Exam III Random Mix Flashcards

Question

Conditioned reinforcer

Answer 1

•associated with a primary reinforcer - something that derives its reinforcing value from primary reinforcers such as money and praise

Answer 2

•repetitive pattern of behavior that violates the rights of other or major societal rules Diagnostic Criteria - 3 for at least 12 months, and one in the last 6 months •aggression to people/animals •serious violation of rules •destruction of property •deceitfulness/theft Treatment •psychotherapy •psychopharmacology -treatment of agression with alpha 2 agonists or mood stabilizers

Answer 3

* A fluent aphasia in which there is good comprehension but poor repetition. Conversational speech is fluent with relatively normal utterance length but marred by paraphasias. * Auditory comprehension is relatively good for casual conversation. Single-word comprehension is well preserved, but patients may have difficulty with complex syntax or multi-step commands. * **Repetition impairment is the hallmark of conduction aphasia**, despite relatively good spontaneous speech. Paraphasias tend to be particularly prominent during repetition tasks. * Naming is always impaired. * Lesion location. Conduction aphasia results from **posterior perisylvian lesions affecting primarily the supramarginal gyrus in the parietal lobe and the arcuate fasciculus**. * Prognosis. Conduction aphasia may persist or may evolve into anomic aphasia.

Answer 4

A contusion is often accompanied by altered consciousness secondary to a head injury. A contusion is caused by blunt trauma, similar to bruise in the rest of the body. The location of the brain damage depends on whether the head is moving or not. The injury will be at the site of impact (coup injury) if the head is stable and struck by a hard object (i.e. a baseball bat). If the head is moving, sudden deceleration will also result in the brain on the opposite side striking the skull. This results in a contrecoup injury which is often larger in size than the coup injury. Brain contusions are characterized by hemorrhage, tissue necrosis and edema. There is a progression of the pathological findings, with neutrophils, followed by macrophages and phagocytosis of necrotic tissue. The injuries are most pronounced at the surface of the brain (crests of gyri) since this is the site of the direct force. The inferior frontal lobes and the inferior surface of the temporal lobes are the most commonly affected because the inner surface of the skull is rough and irregular in these areas. Old contusions are characterized by depressed, yellowish brown patches. •moderate to severe TBI

Answer 5

The physician’s response to the patient; the same emotional expectation that the relationship with the patient will be similar to one from the past.

Answer 6

* Criterion-referenced testing or interpretation involves scoring an examinee’s test performance in terms of how much he/she has mastered the domain being assessed * Results are giving meaning by comparing them with a preset standard (e.g. at Walden Grove High School - “Every student who scores above 75% will pass”) * Also known as content- and domain- referenced testing

Answer 7

* chronic traumatic encephalopathy * first called dementia pugilistica * caused by repeated mild traumatic brain injury * accumulation of tau protein in neurons and astrocytes distributed around small blood vessels at the depths of cortical sulci and in an irregular pattern * tau positive tangles

Answer 8

Damage to the DLPFC impairs mainly “cold” executive functions that require cognitive flexibility such as planning and prioritizing, decision-making, abstract thinking, and working memory. The opposite of cognitive flexibility is perseverance. Cognitive flexibility is manifest when a person is required to shift from one set of the rules to another. The Wisconsin card-sorting task is a classic test of cognitive flexibility and whether there might be damage in the DLPFC. The patient is asked to sort a deck of cards but not how to sort or match the cards; however, the patient is told whether a particular match is right or wrong. As the patient continues you change the rules of how to sort the cards. Patients with DLPFC damage are unable to switch between rules and they perseverate (to repeat something insistently) in sorting the cards based on the first instruction even though they are told it is wrong. Perseveration is a major component of the frontal syndromes in frontotemporal dementia, in adult ADHD, and in multiple behavioral conditions related to trauma to the DLPFC. In other words, the DLPFC plays a role in being able to change cognitive tasks upon changing rules – or adapt quickly in figuring out tasks. •Working Memory - n-back and delayed response task - dopamine •problem solving, planning, sequencing

Answer 9

Damage to the VMPFC leads to preserved working memory and reasonable planning but severe disruption in social behavior, judgment, impulsivity, and personality. Typically patients with ventromedial PFC lesions become impulsive. Impulsivity can be tested by the Iowa gambling task. The VMPFC computes the value of rewards, punishments, risks, and even of regret based on the time elapsed between the stimulus and the outcome.The VMPFC computes the value of rewards, punishments, risks, and even of regret based on the time elapsed between the stimulus and the outcome. The VMPFC computes the value of rewards, punishments, risks, and even of regret based on the time elapsed between the stimulus and the outcome.

Answer 10

•Decerebrate posture is an abnormal body posture that involves the arms and legs being held straight out, the toes being pointed downward, and the head and neck being arched backward. The muscles are tightened and held rigidly. This type of posturing usually means there has been severe damage to the brain.

Answer 11

•Decorticate posture is an abnormal posturing in which a person is stiff with bent arms, clenched fists, and legs held out straight. The arms are bent in toward the body and the wrists and fingers are bent and held on the chest. This type of posturing is a sign of severe damage in the brain.

Answer 12

Dementia with Lewy bodies is the second most common form of degenerative dementia after Alzheimer’s disease. As with any dementia a decline in cognition is seen in dementia with Lewy bodies. Associated findings include delusions and hallucinations. These are seen early in the process of the illness. Additionally, individuals are sensitive to medications. Dopaminergic medications may exacerbate the experience of psychosis. Dopamine blocking agents may lead to rigidity and features of Parkinson’s. Despite the overlap with Parkinson’s, dementia is the prominent symptoms and motor signs are less severe. Often the course of the illness is recognized as fluctuating and families will report that at one moment the patient seems completely normal, while at another they are completely confused. Another associated symptom is REM sleep behaviors. The person may start talking in their sleep, walking in their sleep or even acting out their dreams. Unlike Parkinson’s where Lewy bodies are visualized in the midbrain, especially the substantia nigra, in dementia with Lewy bodies, Lewy bodies are found in the brainstem as well as widespread throughout the cerebral cortex.

Answer 13

•immature defence mechanism •direct disavowal of a painful reality that is overwhelmingly disturbing

Answer 14

These diffuse infiltrating astrocytomas show only a mild increase in cellularity, minimal atypia and no mitoses. MRI scans show an ill-defined, non-enhancing expansion of brain parenchyma because of infiltration of the neoplastic cells. IDH mutation is present in the majority of cases. The median time survival of a patient IDH mutant diffuse astrocytoma is approximately 10 years. Without IDH mutation, the median time for survival is 4-5 years.

Answer 15

The diffuse astrocytoma is the most common primary brain tumor. Diffuse astrocytomas are commonly seen in the cerebral hemispheres of adults but can occur at any age and in any location. A diffuse astrocytoma is characterized by neoplastic astrocytes that migrate and infiltrate as single cells within brain parenchyma. For that reason they are commonly termed diffuse and infiltrating. Three Grades: no Grade I because it cannot be resected * diffuse astrocytoma (WHO Grade II) * anaplastic astrocytoma (WHO Grade III) * glioblastoma (WHO Grade IV)

Answer 16

Severe head trauma resulting in a coma is often accompanied by diffuse axonal injury. This is commonly seen within the deep white matter especially the corpus callosum and periventricular white matter. It is caused when there is movement of the brain within the skull and axons are injured by mechanical forces. Rotational acceleration and deceleration cause shearing forces which tears axons. Microscopically, diffuse axonal injury is characterized by widespread axonal swelling. Axonal transport continues even after an axons is torn, which leads to a build-up of proteins in the segment still attached to the cell body. Ultimately, diffuse axonal injury causes degeneration of the fiber tracts distal to the torn axons

Answer 17

* severe head trauma * deep white matter, especially corpus callosum and periventricular white matter * mechanical forces - rotaional acceleration and deceleration * widespread axonal swelling * ultimately diffuse axonal injury causes degeneration of fiber tracts distal to the torn axons * any severity of injury

Answer 18

•immature defence mechanism •unconscious process by which feelings attached to one source are redirected to another

Answer 19

•frequent, severe, recurrent temper outbursts and chronically irritable and/or angry mood - decrease misdiagnosis of pediatric bipolar disorder Diagnostic Criteria •severe outbursts Treatment •still working on it...

Answer 20

•immature defence mechanism •the splitting off one’s thoughts and associated feelings from conscious awareness

Answer 21

Imprecise articulation due to muscle weakness or incoordination that results from damage to motor areas (including motor cortex, basal ganglia, cerebellum, upper motor neurons, lower motor neurons, neuromuscular junction, or muscle)

Answer 22

Regulation of one’s own emotions Decision making and risk taking Impulse control Insight and foresight The ability to maintain social relationships Depends on the ventromedial PFC (VMPFC) Linked to reward and punishment

Answer 23

Not surprisingly, ependymomas are typically located in the ventricles (IV ventricle\> lateral ventricles\> III ventricle\> aqueduct of Sylvius). Growth of ependymomas into a ventricle will obstruct of the flow of CSF resulting in hydrocephalus from. These tumors also have a tendency to spread through the CSF. Microscopically these tumors show a fibrillary background with structures termed rosettes. The rosettes are arrangements of tumor nuclei around a lumen (true ependymal rosette) or around a capillary (perivascular pseudorosettes). The survival after the diagnosis of ependymoma is variable depending on the extent of resection and location.

Answer 24

Between the dura and the skull - associated with skull fractures. Often due to a tear in the middle meningeal artery. Sudden, rapidly evolving neurologic symptoms

Answer 25

•withholding the consequences that reinforce behavior •extinction burst

Answer 26

* variety, primarily involve the CNS and others that include the CNS along with many other systemic sites * may be due to a mutation in an ioncogene resulting in an increase in function driving toward cancer cell proliferation or loss of function of a gene that normally acts as a tumor suppressor ex. neurofibromatosis 1 and 2, tuberous sclerosis, Von Hipple-Landau disease

Answer 27

•immature defence mechanism •seen when one avoids seeing their own mistakes and continue behavior, or react to a situation, even though it has been determined to be maladaptive

Answer 28

•No behavior will be reinforced until the time has elapsed •engaging in the behavior is pointless until the time elapses •rate of behavior increases near the end of the interval in a rapid and steady manner

Answer 29

•a behavior is reinforced when it has occurred a fixed number of times •perform at a high rate, often punctuated by short pauses after the reinforcement - post reinforcement pauses •FR1 = CRF Ex: paid for each shirt sewn or each bushel picked

Answer 30

Clinical observations indicate that damage around the walls of the third ventricle in the mid-to-caudal hypothalamus cause drowsiness and lethargy. Conversely, damage in the vicinity of the lamina terminalis causes inability to sleep. Thus, there appear to be additional sleep and wakefulness centers in the forebrain. Yet another collection of monoaminergic neurons is located in the hypothalamus near the mammillary bodies (in the tuberomammillary nucleus). Like neurons of the locus ceruleus and raphe nuclei, they project to widespread CNS areas, in this case releasing histamine (Fig. 5). Histamine depolarizes both thalamic and cortical neurons, and turning these histaminergic neurons off causes drowsiness or sleep (like antihistamines such as Benadryl® that block the H1 receptor). In addition, a set of neurons in the lateral midhypothalamus has widespread excitatory connections that use a neuropeptide called orexin (also known as hypocretin) (Fig.6) that may be the master controller since they communicate with the histamine neurons and the ARAS of the brainstem. Finally, cholinergic neurons of the basal nucleus increase the excitability of cortical neurons. GABAergic neurons of the preoptic region and anterior hypothalamus periodically inhibit the orexin and histamine neurons and the other wakefulness-promoting neurons, helping to cause sleep. These neurons get input from the suprachiasmatic nucleus.

Answer 31

The symptoms of the frontal syndrome include loss of desired behavior and gain of undesired behavior. The losses of desired behaviors include: abulia (lack of will), apathy, lack of spontaneity, akinetic mutism, pseudodepressive state, lack of drive, poor motivation. The gains of undesired behaviors include: unjustified euphoric state, distractibility, impulsivity, disinhibition, irritability, restlessness, moria (childish excitement, not Middle Earth), pseudopsychopathic state, anosognosia, indifference, confabulation, and perseveration. Clinically, it is important to recognize the symptoms because the diagnosis of frontal syndrome interferes with decisions making and has major implications for the patient’s autonomy. The frontal syndrome is prevalent because it can appear as a central entity (e.g., in traumatic brain injury, stroke, and tumors in the frontal lobe) or it can accompany other disorders such as adult forms of attention-deficit disorder (ADHD), addiction, schizophrenia, various forms of dementia (especially fronto-temporal dementia), and also to some degree normal aging. Classically the symptoms of the frontal syndrome can be grouped into three clusters: 1) Cognitive Deficits 2) Supervisory Deficits 3) Deficits of Initiation and Inhibition links between the prefrontal cortex and the basal ganglia - motor loop - cognitive loop: DLFPC, caudate nucleus and dorsolmedial This loop is responsible for the initiation and termination of cognitive processes involved in focused attention on a task, planning, and loading or erasing the content of working memory. This loop initiates and terminates thoughts the same way the motor loop initiate and terminates movements. - limbic loops that regulate emotional behaviors, emotional impulses, and in general drive-related behaviors: anterior cingulate cortex, the surrounding medial PFC, and the nucleus accumbens. While the motor loop receives dopamine from the substantia nigra, the cognitive and limbic loops receive dopamine from the ventral tegmental areas. * trauma, tumors, infections (dental abscesses) and symptoms depend on the prefrontal region affected * diagnosis requires symptoms form all three classes * ADHD - rarely finish their education (deficits of concentration, planning, organization), they cannot hold a job (they are unreliable, disorganized, inefficient, socially and emotionally impulsive) and cannot manage their finances, their health care, their family obligations. Typically, adult ADHD has comorbidities with anxiety and depression (as their deficits are regarded as flaws of character rather than a veritable mental dysfunction) and they are powerless in overcoming the challenges of school, work, and everyday life without psychiatric attention. Adult ADHD patients respond well to stimulants, SNRI’s, and recently to blood pressure medications. •schizophrenia - often unable to separate and process accordingly task-relevant and task-irrelevant information. This process requires a normal flow of information between the prefrontal cortex, other association cortices, and the other areas of the brain. These types of deficits led to the formulation of disconnection syndromes that are frontal syndromes caused by remote lesions, such as strokes in the thalamus or the basal ganglia. Both clinical and recent MRI studies show that frontal lobe dysfunction can be caused by damage to areas outside the prefrontal cortex. The explanation for this phenomenon (called diaschisis) is the dynamic interruption of circuits established between the prefrontal cortex to other areas of the brain. The disruption of a single segment of these circuits is sufficient to compromise the complex functions of the entire prefrontal cortex. DLPFC (cognitive): - Working memory, problem solving, mental flexibility, symbolic thinking - distracted on delayed responses task, cannot solve the Tower of Hanoi, persevernace on card sorting task, cannot explain proverbs/concepts VMPFC (supervisory): - impulse control, emotional stability, social incompetence - losses on Iowa ganbling task, frequent mood swings, lack of empathy and inability to obey social rules DLPFC/VMPFC (initiation/inhibition): - motor perseverance, verbal perseverence, inability to function - utilization behavior, poor word generation/echolalia, lack ofmotivation and organization to carry out simple daily activities

Answer 32

Frontotemporal dementia is thought to be at least as common as early-onset Alzheimer’s dementia (Alzheimer’s that develops before the age of 60). The prevalence may be approximately 15 per 100,000 persons aged between 45 and 64 years. Generally speaking, individuals tend to present with frontotemporal dementia at a younger age compared to individuals with Alzheimer’s. Variants of frontotemporal include a behavioral form where changes in personality and behavior are seen early on. They also tend as a group to have disordered initiation, goal-setting and planning. Another form of frontotemporal dementia has a greater impact on language. Individuals with this form exhibit profound anomia associated with progressive loss of conceptual knowledge of words . Patients with predominantly right temporal degeneration are associated with deficits in empathy and knowledge about people’s emotions. MRI is the best imaging modality for visualizing atrophy. CTs are good if the person is unable to get an MRI. Functional imaging such as SPECT and PET scans are becoming more common. Most often these modalities are most helpful to confirm suspicion of dementia type such as frontotemporal dementia, where decreased metabolism in the frontal and temporal lobes might be seen, versus Alzheimer’s, where decreased metabolism in the parietal and posterior temporal areas may be seen initially.

Answer 33

Are used to induce states of: 1) analgesia 2) amnesia 3) loss of consciousness 4) skeletal muscle relaxation 5) inhibition of sensory and autonomic reflexes 2 important physiological effects: 1) hyperpolarize neurons 2) modulate synaptic transmission

Answer 34

This is a diffuse infiltrating astrocytoma with features of anaplastic astrocytoma (mitotic figures) but also necrosis and/or microvascular proliferation. In many cases the tumor cells line up around the necrosis and this feature is termed pseudopalisading necrosis. The microvascular proliferation is so abundant that there are loops upon loops of endothelial cells resembling renal glomeruli (glomeruloid vascular proliferation). This is due to the secretion of a vascular endothelial growth factor by the tumor. Glioblastomas commonly infiltrate through the white matter tracts of the corpus callosum into the other hemisphere resulting in a characteristic “butterfly appearance” grossly. Glioblastomas often appear as ring-enhancing lesions on MRI scans due to central areas of necrosis and a ring-like enhancement due to breakdown of the blood brain barrier from the proliferating vessels. This “ring enhancing” appearance may also be seen with abscess formation, metastases, or primary CNS lymphoma. Rarely, acute multiple sclerosis can show a mass lesion with ring enhancement. Because the neoplastic cells travel widely along white matter tracts, even when the scans look like the tumor has been totally removed by surgery (called a gross-total resection), there are microscopic cells left behind. Glioblastoma has a bad prognosis, with most patients dying within 1-2 years after diagnosis. MGMT promotor methylation and IDH mutations are favorable prognostic features.

Answer 35

* A severe nonfluent aphasia with poor auditory comprehension and poor repetition. Conversational speech is nonfluent with slow, halting speech production. Utterances may be restricted to single words or phrases that are perseverative, such as I can see. * Auditory comprehension is reduced to the extent that even single-word comprehension is significantly compromised. Comprehension is markedly impaired at the phrase or sentence level. * Repetition is defective and even single words may not be repeated accurately. * Naming is severely impaired. * Lesion location. Lesions in global aphasia are extensive and **typically involve the entire left perisylvian language zone**. A common cause is embolic occlusion of the main stem of the middle cerebral artery. * Prognosis. Global aphasia may evolve to Broca’s aphasia, or it may persist as global aphasia.

Answer 36

* a hereditary (autosomal dominant) disorder that affects the basal ganglia and the cerebral cortex. The onset of symptoms is usually in the 4th to 5th decades. The clinical findings are characterized by a triad of involuntary movements (chorea), dementia and psychiatric disturbances (especially depression). Movement abnormalities include chorea, dystonic posturing and dysarthria. Pathologically, Huntington’s disease is characterized by symmetrical degeneration of caudate nucleus and putamen, which may be seen on CT scan. There may also be degeneration of the frontal lobes. Microscopically, loss of neurons with gliosis is seen in caudate and putamen * the CAG trinucleotide region is expanded in length in a gene that encodes a protein called huntingtin. Although the function of the huntingtin protein is unknown, it is essential, because targeted gene disruption in the mouse leads to a lethal phenotype. The normal huntingtin gene has less than 26 CAG repeats. With a repeat count of more than 40, there is full penetrance of the gene and the disease will be transmitted in an autosomal dominant fashion. The longer the CAG repeat region, the earlier and more severe the disease. There is a tendency of repeats to expand when transmitted from parent to child (called anticipation). The long polyglutamine region results in protein misfolding which impedes clearance. This toxic misfolded protein can be demonstrated in the nucleus of caudate neurons by immunohistochemistry

Answer 37

•mature defence mechanism •ability to playfully poke fun at yourself and the situation you are in

Answer 38

•immature defence mechanism •when one sees another individual as perfect and ignores any faults of that individual

Answer 39

•immature defence mechanism •occurs when one perceives another as a threat and tries to emulate their behavior in an unconscious effort to pacify them

Answer 40

Infant and preschool tests are generally considered valid as screening devices for developmental delays and disabilities * Prior to Age 2 - little predictive validity * E.g., Denver Development Screen Test, Bayley Scales, Fagan Test of Intelligence

Answer 41

•immature defence mechanism •thinking or talking about an emotional subject in an unemotional way

Answer 42

Intelligence Quotient (IQ) – is a general estimate of the functional capacity of a person. IQ is not an absolute score, but a comparison among people. Studies suggest that 70% is inherited. * Previously used IQ formula: – Mental age (MA) method: • IQ = mental age/chronological age x 100 – \*\*Now use standardized tests * Verbal IQ; Performance IQ; Full scale IQ * Wechsler Adult Intelligence Scale (WAIS-R) (ages \>17) * Wechsler Intelligence Scale for Children, fifth edition (WISC-V) (ages 6:0 – 16:11) * Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV) (ages 2:6 – 7:7) * Stanford-Binet Intelligence Scales, 5th edition (ages 2 – 85) * Universal Nonverbal Intelligence Test 2 (UNIT2) (ages 5 – 21:11)

Answer 43

Contusions can lead to bleeding into the brain, preferentially at the crests of gyri Other causes of brain hemorrhage include hypertension, cerebral amyloid angiopathy, tumors and vascular malformations.

Answer 44

•immature defence mechanism •separation of affect from ideation

Answer 45

Development of the K-ABC was based on Luria’s distinction between sequential and simultaneous processing • Emphasis on nonverbal items, makes it – “culturally-fair” and appropriate for – language impaired

Answer 46

* mutations in genes whose protein products are involved in the generation, turnover or maintenace of myelin * unlike demyelinating diseases, these diseases present at an early age and are characterized by progressive deterioration of cerebral function * diffuse, symmetric deterioration of white matter * Krabbe disease, metabolic leukodystrophy and adrenoleukodystrophy

Answer 47

* Alert * Lethargic (somnolent): drowsy and may fall asleep if not stimulated in some way, easily sidetracked * Obtunded: difficult to arouse froma somnolent state and is frequently confused when awake, repeated stimulatoin to maintain consciousness, unproductive interactions with examiner * Stuporous (semicoma): responds only to strong, generally noxious stimuli, when aroused patientis unable to interact with examiner * Coma (deep coma): cannot be aroused by any type of stimulation, reflex motor responses may or may not be seen

Answer 48

* basal pontine storke could destroy the descending corticospinal and corticobulbar fibers bilaterally but leave the ARAS intact * normal sleep-wake cycles but unable to communicate except with limited eye movements

Answer 49

* characterized by mutations in the genes encoding lysosomal enzymes - loss of function of these enzymes leads to accumulation of storgae material which may eventaully lad to cell death * can be divided into catefores based on the nature of the accumulated material * predominanlty grey matter (neuronal storage disease) or white matter (leukodystrophy) or both * systemic disease may also be observed * neuronal storage disease: accumulation of storage material within neurons usually leading to death of cell ex. Tay-Sachs, Niemann-Pick Disease, mucopolysaccharidoses and ceroid lipofuscinosis * Leukodystrophies: mutations in genes whose protein products are involved in teh generation, turnover or mainteneance of myelin ex. Krabbe disease, metabolic leukodystrophy and adrenoleukodystophy * Metachromatic leukodystrophy: an autosomal recessive lysosomal storage disorder

Answer 50

This is an undifferentiated tumor with a high nuclear/cytoplasmic ratio (small blue cell tumor) and frequent mitoses. Some may show rosettes with a fibrillary center (Homer-Wright Rosettes). By definition, medulloblastomas are found in the cerebellum. Tumors with this undifferentiated morphologic appearance in other areas of the brain are called CNS embryonal tumors. Medulloblastomas are extensively subdivided based on morphology and molecular characteristics and these features will impact prognosis. Many medulloblastomas are very responsive to radiation treatment with a 75% five-year survival after treatment. Because of the tendency of these tumors to spread through the cerebrospinal fluid, radiation of the entire brain and spinal cord (the entire neuroaxis) is necessary.

Answer 51

These tumors show the differentiating features of meningothelial cells. Histologically they are characterized by benign appearing nuclei with indistinct cellular borders, whorl formation and psammoma bodies. Grossly, they are well-circumscribed tumors that compress but generally do not invade the brain. They typically are attached to the dura. Most meningiomas are slowly growing and have an excellent prognosis if completely excised. Meningiomas with atypical features (WHO grade II, with mitoses, necrosis, increased cellularity and atypia) have a higher rate of recurrence. Brain invasion signifies a greater tendency for recurrence after excision and are also considered WHO grade II tumors (atypical meningiomas). An anaplastic meningioma (WHO grade III) is a highly aggressive tumor with the appearance of a high-grade sarcoma and very high mitotic rates.

Answer 52

• an autosomal recessive lysosomal storage disorder caused by the deficiency of aryl-sulphatase A. Deficiency of this enzyme causes lysosomal storage of the sphingolipid cerebroside sulphate (a sulfatide), a lipid that is abundant in myelin. Storage of sulfatides in the lysosomes of oligodendroglial cells and Schwann cells is toxic resulting in demyelination of both the CNS and PNS. Within the brain and peripheral nerve, the storage material may also be identified in macrophages. Clinically the disease is heterogeneous, and there are three different types of metachromatic dystrophy which vary by age of onset. The name of the disease “metachromatic” is based on the brown color of the storage material when stained using a blue dye.

Answer 53

Metastatic tumors are high on the differential diagnosis of ring-enhancing lesions on MRI. The microscopic appearance is similar to the primary tumor: e.g. carcinoma, sarcoma, lymphomas. Lung, breast, skin (melanoma), gastrointestinal and kidney are the most common sites of origin.

Answer 54

•The definition of minimally conscious state is not completely codified. The minimally conscious state is defined as severely altered consciousness in which minimal but definite, sustained and/or reproducible behavioral evidence of awareness of self or environment is demonstrated. The person may have periods where they can communicate or respond to commands, such as moving a finger when asked. A person may enter a minimally conscious state after being in a coma orvegetative state. In some cases a minimally conscious state is a stage on the route to recovery, but in others it's permanent. To make the diagnosis of MCS, limited but clearly discernible evidence of self or of environmental awareness must be demonstrated on a reproducible or sustained basis by one or more of the following behaviors: 1. Follow simple commands (eg touch your nose, look up). 2. Gestural or verbal yes/no responses (regardless of accuracy). 3. Intelligible verbalization. 4. Purposeful behavior that is not due to reflexive activity. - Appropriate smiling or crying in response to emotional but not to neutral topics or stimuli - Reaching for objects demonstrating a clear relationship between object location and direction of reach - Touching or holding objects appropriately in relation to the size and shape of the object - Pursuit eye movement or sustained fixation that occurs in direct response to moving or salient stimuli.

Answer 55

* Finally, volatile general anesthetics are administered based on a concept of the minimal alveolar concentration (MAC). MAC is a concept used to compare the potency of volatile anesthetics. MAC concentrations are reported based on the concentration of vapors delivered to the lungs that prevents motor responses in 50% of subjects in response to a painful stimulus. Things that may alter MAC include age (i.e., 6%/decade), hypotension, pregnancy, metabolic acidosis, hypoxemia, body temperature and other medications/medications)…. Most importantly is to understand that the Anesthesia achieved depends upon the brain partial pressure. A good rule to remember is that the partial pressure in the Brain will be equal to the Alveolar partial pressure (i.e., Pbrain = Palveolar). The partial pressure of the alveolar (PA) is a balance between delivery of the medication to the alveolus and uptake of the medication into the blood and the body. Factors that influence uptake include the solubility (i.e., blood:gas partition coefficient), cardiac output and alveolus-venous pressure gradient. Remember the anesthesia one achieves is related to Pbrain = Palveolar ; So, more anesthetic dissolves in the blood, the less remains in the alveoli. More molecules of a soluble gas are required to saturate the liquid phase before increasing partial pressure. Therefore, the lower the blood:gas partition coefficient the faster the onset. (i.e., blood:gas partition coefficients = desflurane 0.45, nitrous oxide 0.47, sevoflurane 0.65, isoflurane 1.8 – speed of onset desflurane\>nitrous oxide\>sevoflurane\>isoflurane). * Some Rules to go by: 1. Greater systemic uptake of anesthetic leads to lower mixed venous anesthetic concentrations and to a slower induction of anesthesia. (It also leads to greater alveolar-venous partial pressure gradients). 2. Lower solubility in the blood compared to alveolar gas (lower blood/gas partition coefficient) leads to more rapid induction of anesthesia. 3. Lower cardiac output leads to more rapid induction of anesthesia.

Answer 56

* The MMPI is used to screen for personality and psychosocial disorders in adults (i.e., over age 18) and adolescents age 14 to 18. It is also frequently administered as part of a neuropsychological test battery to evaluate cognitive functioning. * The MMPI-2 is designed with 10 clinical scales which assess 10 major categories of abnormal human behavior, and four validity scales, which assess the person's general test-taking attitude and whether they answered the items on the test in a truthful and accurate manner. Assess test-taking attitudes to determine if the tests are valid * High L – favorable light * High F – carelessness (eccentric) * High K – clinical defensiveness (faking good) * Score on K is used to correct scores on several clinical scales

Answer 57

* Also called the “isolation syndrome” because the perisylvian language zone is disconnected from extrasylvian regions. * It is a nonfluent aphasia with poor comprehension but relatively preserved repetition. Conversational speech is similar to that found in global aphasia, in that meaningful verbal expression is severely limited or is absent altogether. Stereotyped utterances are common, as is echolalia – the inappropriate, and somewhat irrepressible, repetition of what others say. * Auditory comprehension is markedly impaired, often even at the single-word level. Repetition of phrases and complete sentences is preserved, although repetition typically occurs without comprehension. * Naming is significantly impaired. * Lesion location. MTcA is seen in association with **diffuse or multifocal lesions that result in anatomic isolation of the perisylvian language zone from surrounding cortical areas**. * Prognosis. Variable recovery occurs in MTcA; patients in whom the cause is vascular have the best chance of some recovery of language.

Answer 58

This is a strange disorder defined by a variable combination of excessive daytime sleepiness, often accompanied by irresistible sleep attacks; **cataplexy**, a sudden loss of muscle tone during wakefulness, usually triggered by emotion; sleep paralysis, a complete loss of muscle tone during sleep-wake transitions; and hallucinations during sleep-wake transitions. Narcoleptic patients usually have abnormal sleep at night; they typically slip almost immediately into REM and may have many awakenings. In just the last few years the major probable cause of narcolepsy has been figured out. The small group of peptidergic neurons in the tuberal hypothalamus, near the columns of the fornix, that release orexin (aka hypocretin) are selectively lost in most of the narcoleptic brains examined to date, perhaps through an autoimmune mechanism. Loss of input to histaminergic neurons and to REM-control circuitry could explain the symptoms of narcolepsy, and the development of orexin agonists may provide new treatments.

Answer 59

Event that, when removed after a response, increases likelihood of that response occurring again - escape

Answer 60

•a response is followed by the removal of or decrease in the intensity of a stimulus •and averse stimulus an organism tries to “escape” (Alarm clock, seat belt buzzer)

Answer 61

* an autosomal dominant disorder with a frequency of 1 in 3000. In half of the cases it is inherited, with the other half being new mutations. The NF1 gene is very large, with approximately 250,000 base pairs and thus there is a high number of spontaneous mutations. The NF1 gene encodes a protein called **neurofibromin**. This protein is found in many tissues and is thought to be a tumor suppressor gene that normally acts by converting RAS (an oncogene) from an active to an inactive form. RAS plays a key role in promoting cellular growth. A decreased cellular brake on RAS because of a mutated NF1 gene may explain the occurrence of multiple tumors in NF1. * The clinical phenotype does not correlate with the type or location of the mutation, and the clinical course is highly variable. This is an example of variable expressivity, in which there are differing manifestations in people with the same genotype. Persons with NF1 may develop neurofibromas (both solitary and plexiform) of peripheral nerves, gliomas of the optic nerve, pheochromocytomas, Lisch nodules (pigmented nodules in the iris) and multiple cafe-au-lait spots on the skin. * Neurofibromas are commonly found in the skin. They occur as elevated dermal lesions which microscopically consist of haphazard Schwann cells and fibroblasts. Growth may produce a nodule, or over time, a pedunculated mass. A patient with a simple neurofibroma of the skin may or may not have neurofibromatosis. If a neurofibroma expands a nerve to produce a complicated growth, it is termed a plexiform neurofibroma. Massive diffuse and plexiform neurofibromas of the skin may produce large tumors. Multiple skin tumors and/ or plexiform neurofibromas are consistent with a diagnosis of neurofibromatosis. Microscopically, plexiform neurofibromas consist of diffusely proliferating Schwann cells and fibroblasts, often in association with a myxoid (mucus-like) matrix. Because Neurofibromas incorporate the parent nerve, residual axons may be present within the substance of the tumor. Because these tumors grow within the nerve, tumor removal requires sacrifice of the nerve. Neurofibromas can undergo malignant degeneration and this is more likely to occur in larger tumors. Therefore, large neurofibromas that are resected should be examined for evidence of malignancy (numerous mitotic figures and high cellularity). These are termed **malignant peripheral nerve sheath tumors**.

Answer 62

* (central form of NF) is also an autosomal dominant disorder with a frequency of 1 in 50,000 to 100,000. Like NF1, this disease may be inherited or be a result of a new mutation. The NF2 gene produces a protein known as **merlin** which has a structural similarity to cytoskeletal proteins and is widely distributed in tissues throughout the body. This protein functions as a tumor suppressor that mediates contact inhibition of growth through signals from the extracellular matrix. * Patients with NF2 develop vestibular schwannomas (typically bilateral), multiple meningiomas and spinal cord ependymomas. The schwannoma is a well circumscribed, encapsulated, benign tumor of Schwann cells attached to a peripheral or cranial nerve. Bilateral vestibular schwannomas are the hallmark of NF2. (Schwannomas are also common tumors throughout the peripheral nervous system and in the cranial nerves in individuals without gene mutations.) Vestibular schwannomas are located at cerebellopontine angle of the brainstem, attached to the vestibular portion of the eighth nerve. Microscopically, these tumors have a biphasic pattern with spindled cells palisading in compact zones (Antoni A) and microcystic zones with a loose meshwork of cells (Antoni B).

Answer 63

One of the most useful ways to compare an individual’s performance on a test to the test scores of others. * Norms are average scores computed for a large representative sample of the population. * Focus on validity and reliability of test * An appropriate normative sample answers these: – How large is the sample? – When and Where was the sample gathered? – How were individuals identified and selected? – What was the composition of the sample (i.e. age, gender, sex, ethnicity, SES, education level, etc.)? Intelligence

Answer 64

– Utilize simple stimuli – Have a restricted range of possible responses (provided options) – Scored mechanistically using a standardized scoring key – Requires no clinical experience to score – Some tests require specific training or a particular license to administer

Answer 65

Tumors that show the differentiating features of oligodendroglial cells are most commonly found in the cerebral hemispheres of adults. Microscopically they are characterized by monotonous cells with round nuclei and clear cytoplasm (fried egg appearance), fine capillaries in chicken wire distribution and calcification. Oligodendrogliomas are diffusely infiltrating tumors similar to the diffuse astrocytomas. On imaging, they are difficult to distinguish from low grade astrocytomas. They tend to be calcified but a small proportion of diffuse astrocytomas can also have calcifications. A characteristic feature of oligodendrogliomas is loss of chromosomes 1p and 19q. Similar to grade astrocytomas, oligodendrogliomas are usually IDH mutant. Most are WHO grade II, but higher grades are also seen.

Answer 66

•striated muscles an volition •reinforcement INCREASES BEHAVIOR \*positive: event that when presented after a response, increases likelihood of that response again \*negative: event that, when removed after a response, increases likelihood of that response run again - escape •punishment \*consequences that reduce the strength of behavior

Answer 67

•conflict with authority Diagnostic Criteria •6 on this with 4 symptoms Treatment •psychotherapy •psychopharmacology -aggression: clonidine, guanfacine –hyperactivity/inattention: clonidine and guanfacine or stimulants - methylphenidate and amphetamine salts or atomoxetine -anxiety and/or depressive symptoms: alpha 2 agonists or atomoxetine

Answer 68

encodes value to both internal and external characteristics

Answer 69

Many cortical lesions extend to subcortical regions, but aphasia can also result from deep lesions that appear to spare the cerebral cortex. Subcortical aphasias include thalamic aphasia and aphasia associated with damage to the basal ganglia and surrounding white matter pathways. Language impairment is one of the symptoms of generalized cognitive decline associated with dementia. In the case of Alzheimer’s disease, language deterioration typically follows a progressive course that begins with anomic aphasia, proceeds to transcortical sensory aphasia, and then to Wernicke’s aphasia, and ultimately becomes global aphasia. In some patients, progressive language deterioration occurs without significant dementia and is referred to as primary progressive aphasia (PPA).

Answer 70

• Sentence Completion Test – Semi-structured: provided with “stems” to complete – Discovering attitudes, beliefs, motivations or other mental states • Projective Drawings (e.g. Draw-A-Person test) – Provided with a sheet of paper asked to draw a house, tree, person, family, etc. – Limited validity (pathology or poor artist?)

Answer 71

incorrect word choice and sound substitution errors

Answer 72

* Parasomnias are undesirable physical or behavioral phenomena that occur predominantly during sleep. * disorders of arousals, such as **sleepwalking** or **night terrors**; -classic disorders of arousal include sleepwalking, sleep terrors, and confusional arousals. These behaviors are more common in children and adolescents and are characterized as events occurring as partial arousals from the deeper stages of SWS. Sleep terrors start with a piercing scream or fright with significant sympathetic nervous system output. Patients have tachycardia, pupillary dilation, and sweating and appear wide-eyed and inconsolable. They occur during the deepest stages of SWS (stage III/IV) and therefore, unlike nightmares, often cannot remember the arousal episode. Confusional arousals occur following sudden awakening and may be accompanied with disorientation and the patient striking out. * sleep-wake transition disorders, such as **sleep talking**; **rhythmic movement disorder** (e.g., head banging); * REM parasomnias, such as REM sleep behavior disorder **(RBD)** -malfunction of parts of the brainstem responsible for suppressing muscle tone during REM sleep can cause patients (usually older males) to thrash around in bed, sometimes seemingly acting out their dreams. Occasionally this is associated with a pontine lesion, but typically the cause is unknown.

Answer 73

•immature defence mechanism •occcurs when aggressive feelings to thoughts are disavowed, so one may engage in other behaviors as an outlet for the aggressive cognitions

Answer 74

* Either spontaneously or in response to stimuli, comatose patients may assume postures that are correlated with the level of the damage. The names decorticate and decerebrate have come to be associated with two of these postures. * **decorticate posturing** usually means damage in the **rostral midbrain or above** * **decerebrate posturing** usually means damage **below the rostral midbrain**. * A transition from decorticate to decerebrate can mean something like compression moving down the brainstem.

Answer 75

* Lots of things can cause changes in behavior of the pupils. There are metabolic, pharmacological (i.e., opiates, excess acethylcholine) or diencephalic damage that causes a bilateral, small pupils that remain reactive to light. * When **both pupils** are **dilated and fixed** (do not react to light) it could be a sign of diffuse damage, global hypoxia, barbiturates or atropine. * One might expect various kinds of midbrain damage affecting parts of the pupillary reflex arc to have an effect on pupil size (e.g., uncal herniation can push unilaterally on CN III and cause one pupil to be dilated and fixed). * In addition, **bilateral pontine damage that causes coma typically results in tiny but still-reactive pupils.** This apparently results from damage to descending sympathetic neurons (as in Horner’s syndrome) combined with disruption of normally present inhibitory inputs to the Edinger-Westphal nuclei. * Whereas **bilateral midbrain damage can result in pupils that are in a mid-position and fixed**.

Answer 76

* There are a few repiratory patterns in coma that are diagnostic for the location of damage. * **Cheyne-Stokes respiration**, is a waxing and waning breathing pattern with a period of 10–20 seconds, that indicates **bilateral diencephalic damage, cardiac failure, or acidosis**. * Damage to the **pontine respiratory centers (e.g., parabrachial nucleus) causes a pattern of respiration called apneustic breathing** characterized by deep, gasping inspiration with a pause at full inspiration followed by a brief exhale. * **Upper medullary damage causes a respiratory pattern called ataxic breathing** that is irregular and has periods or disorganized sequences of inhales and exhales interleaved with periods of apnea but some automaticity is still there because the pre-Botzinger cells are still intact. Finally, when the damage spreads to the preBotzinger complex of the medulla respiration ceases (respiratory failure).

Answer 77

WHO Grade I These tumors commonly occur in the cerebellar hemispheres of children. Grossly, the pilocytic astrocytoma is a wellcircumscribed, homogeneously enhancing nodule associated with cyst formation. Microscopically there are pilocytic (hair-like or elongated) regions with eosinophilic inclusions termed Rosenthal fibers. The solid areas alternate with cystic regions that contain fluid. Mitotic figures are rare. The circumscription of pilocytic astrocytomas allows complete resection and therefore these tumors have an excellent prognosis.

Answer 78

Event that, when presented after a response, increases likelihood of that response occurring again

Answer 79

•appetitive stimulus - food, water, physical contact

Answer 80

We must make the distinction between speech and language production. Speech production involves moving the muscles, bones, and cartilage involved in articulation, primarily in the lower airway, larynx, pharynx, and mouth. Speech is the motor act that carries the linguistic message. Disorders of motor control for speech are distinct from language impairments, but can co-occur with aphasia.

Answer 81

•immature defence mechanism •unwanted wishes/feelings displaced onto another person

Answer 82

* Use ambiguous stimuli and have a wide range of possible responses. * Response meaning is interpreted (content analyzed) by clinical correlation between collected cases of responses and personal characteristics (psychopathologies). * Tests are only scored by experienced clinicians using consensual standards * Origins in psychoanalysis

Answer 83

Consequences that reduce the strength of behavior •Type 1 - positive •Type 2 - negative

Answer 84

•immature defence mechanism •attributing a behavior to a cause that is thought to be more acceptable than the actual cause

Answer 85

•immature defence mechanism •warding off an unacceptable wish/impulse by adopting a character trait that is diametrically opposed to it

Answer 86

•immature defence mechanism •seen when one reverts to an earlier developmental stage when feeling threatened by uncomfortable thoughts or feelings

Answer 87

•how and what is delivered •size, amount and quality

Answer 88

Event is reinforcing if it allows you to engage in something you are deprived of (eating when hungry etc...)

Answer 89

Events are no longer reinforcing if satiety has occurred due to prior access

Answer 90

The triggers for REM sleep are also built into the brainstem, as is the machinery for many of its peculiar features. After a midpontine transection the forebrain is constantly awake, as described previously. In contrast, the parts of the brain caudal to the cut begin to cycle through parts of REM sleep without regard for what the forebrain is doing. That is, muscle tone periodically vanishes and there are superimposed twitches of the lateral recti. The cells responsible for REM sleep reside in the reticular formation from the rostral pons to the caudal midbrain. Cholinergic neurons in the reticular formation become active during REM sleep, and move thalamic neurons back into tonic mode, triggering the other parts of REM sleep (Fig. 7). Microinjection of an acetylcholine agonist into nuclei of the reticular formation results in extended periods of REM sleep. The REM sleep machinery probably chugs along constantly with a 90-minute cycle, only reaching threshold when disinhibited during non-REM sleep. The nature of the “clock” for the 90- minute cycle is unknown, but periodic firing of raphe and locus ceruleus neurons help to terminate episodes of REM sleep. There are clinical syndromes in which parts of REM sleep intrude into the waking state.

Answer 91

REM sleep is a much more peculiar state, with both phasic and tonic characteristics. * Heart rate, blood pressure and respiratory rate increase again. * Muscle tone disappears almost completely, due to inhibition of both alpha and gamma motor neurons. * The hypothalamic thermostat shuts off, and we become reptilian in terms of temperature regulation. * Superimposed on this baseline are bursts of rapid eye movements (hence the name REM sleep) and twitches of other muscles. * Cerebral blood flow increases almost to waking levels. * People awakened from REM sleep are very likely to report that they were dreaming, and that the dream had detailed visual imagery and a story. * We believe REM sleep is necessary since lab rats that go without 5 weeks of REM sleep will end up dyeing. In humans, the rare hereditary condition, fatal familial insomnia (FFI), which is associated with a progressive inability to sleep, invariably leads to death, with a time course of between 8 and 72 months. FFI is caused by an abnormal variant in the prionrelated protein (PRPN) gene in which abnormal prions (misfolded proteins) build up primarily within the thalamus of the brain. This leads to the progressive loss of neurons and the various symptoms associated with this disorder. There is no cure.

Answer 92

•immature defence mechanism •defence used against internal wishes or impulses (as opposed to denial) such as blocking a thought, feeling, or memory from conscious awareness

Answer 93

The unconscious wish by a patient or a physician to maintain the “status quo” and avoid unpleasant feelings.

Answer 94

•Neurodevelopmental disorder •MECP2 mutation •females •typical development for first year, regressive symptoms ages 1-4 •disruptions in social interactions, deceleration in head growth, loss of hand movements and poor coordination, may regain social communication skills with time

Answer 95

Projective personality test * 10 inkblots * Two phases – Free association – Inquiry * Responses presumably reflect underlying personality, conflicts, etc. * Scoring – Location – Determinants – Form Quality – Content – Frequency of occurrence

Answer 96

•continuous •partial -Interval Fixed Variable -Ratio Fixed Variable

Answer 97

•separation from primary caregivers causes developmentally inappropriate levels of distress in a child Diagnostic Criteria •persistent and excessive worry about at least 3 for at least 4 weeks Treatment •psychotherapy •psychopharmacology -SSRIs fluoxetine, sertraline, fluvoxamine -atomoxetine

Answer 98

•an operant conditioning procedure in which successive approximations of a desired response are reinforced

Answer 99

•contrived reinforcers -events arranged by someone to modify behavior or change behavior (therapy, research) •natural reinforcers -events that typically-naturally follow behavior and reinforce (social interactions, Bruce=sing teeth, motivation to exercise)

Answer 100

* pause in breathing, \>10 seconds * oxygen desaturationa nd arousals * light NREM and REM sleep * CNS disease (epilepsy, strokes, head trauma) * peripheral disease (muscular dystrophy and myotonic dystrophy) * obstructive and central

Answer 101

We have many physiological rhythms with a period of about a day—circadian rhythms including body temperature, hormone secretion, sleep and wakefulness, etc. The master clock for these rhythms is the suprachiasmatic nucleus of the hypothalamus. If all cues about day length are removed, the clock and the rhythms it coordinates “free run” with a period typically of about 25 hours. Light/dark information reaches the suprachiasmatic nucleus directly from the retina, and entrains it to a 24-hour cycle. The photic influence is enhanced by cyclic secretion of melatonin by the pineal gland (suprachiasmatic neurons are loaded with melatonin receptors). Other entraining inputs also reach the suprachiasmatic nucleus, probably by way of serotonergic fibers from the raphe nuclei, but they are less powerful than photic input. How this timing machinery in the hypothalamus normally interacts with the ARAS to produce sleep-wake cycles is not completely known. Yet, neurons in the most anterior part of the hypothalamus (the preoptic area (Fig. 8) send inhibitory projections to most or all parts of the wakefulness-promoting network. It is thought that the preoptic neurons receive input from the suprachiasmatic nucleus about light/dark and when activated result in the inhibition of histaminergic, orexinergic and possibly the ARAS neurons.

Answer 102

Awake: beta waves Awake but Sleepy: alpha waves Stage I: light sleep, theta waves Stage II: deeper sleep, sleepspindles and K-complexes Stages III and IV: deepest sleep, delta waves Slow Wave Sleep - Stages I-IV, wave amplitude gets larger with less cycles/time

Answer 103

* Stages I-IV * heart rate, blood pressure, respiratory rate and set pont of hypothalamci thermostat deccrease, gut motility increases * blood flow to the brain decreases, particularly in the thalamus, basal ganglia, and multimodal cortical association areas * muscle tone decreases because of inhibition to gamma motor nerons, but tone is not abolished (rolling around, deepest stages --\> sleep walking) * not much in the way of dreams

Answer 104

•immature defence mechanism •transfer of painful feelings to body parts such that emotional concerns are expressed through physical complaints

Answer 105

•immature defence mechanism •seeing others in black or white terms, and/or polarising one’s views/beliefs into all good or all bad attributes

Answer 106

•discrimination is when learned behavior occurs in one situation but not in other situations. When discrimination learning brings behavior under the influence of discriminate stimuli, the behavior is said to be under “stimulus control” (braking when light is red) •sometimes stimulus control is exerted by a complex array of stimulithat collectivley influence behavior (formal ball)

Answer 107

•gradual removal of either a prompt or reinforcement

Answer 108

•increased ratio of dopamine to serotonin metabolites in their CSF (impulsiveness, disinhibition, aggression) •low amygdala activity (inability to learn from punishment and inability to associate one’s actions with the pain it causes to others)

Answer 109

•anterior cingulate gyrus (increased aggression, inability to autocorrect) •orbitofrontal areas (impulsivity and poor emotional regulation) •amygdala (impaired facial expressions perception, poor regulation of the autonomic expression of emotion) •hippocampus (although the memory function of these patients can be intact) •insula (lack of empathy, no concept of fairness)

Answer 110

•reduced volume of the pulvinar and of the mediodorsal nucleus of the thalamus •abnormalities in the shape and volume of the corpus callosum •abnormalities in temporal lobe structures including the superior temporal gyrus, parahippocampal gyrus, amygdala and hippocampus •abnormal dopamine synthesis and metabolism, aberrant eye movements, cognitive deficits and several electrophysiological abnormalities

Answer 111

Into the subarachnoid space. Although often associated with spontaneous rupture (non-traumatic) of a Berry aneurysm, subarachnoid hemorrhage can also be caused by trauma. Traumatic damage to vessels from blunt injury (contusions) can lead to bleeding in the subarachnoid space.

Answer 112

Between the dura and the arachnoid membrane. Movement of the brain when the dura is fixed to the skull tears the bridging veins. May be delayed from the time of injury

Answer 113

•mature defence mechanism •unconscious process by which socially unacceptable drives/wishes are channeled into socially acceptable alternatives

Answer 114

•mature defence mechanism •a portly conscious mechanism to banish unacceptable thoughts/feelings from your mind

Answer 115

* classic example of a neuronal storage disease * secondary to a mutation in the beta-hexosaminidase A gene whcih helps break down Gm2 gangliosides * autosomal recessive, progressive neurodegenerative disease, fatal by 2-3 yo * margins of retina --\> cherry red spot

Answer 116

Stage 1 Anesthesia, also known as the "induction", is the period between the initial administration of the induction agents and loss of consciousness. During this stage, the patient progresses from analgesia without amnesia to analgesia with amnesia. Patients can carry on a conversation at this time. Stage 2 Anesthesia, also known as the "excitement stage", is the period following loss of consciousness, marked by excited and delirious activity. During this stage, respirations and heart rate may become irregular. In addition, there may be uncontrolled movements, vomiting, breath-holding,and pupillary dilation. Since the combination of spastic movements, vomiting, and irregular respirations may lead to airway compromise, rapidly acting medications are used to minimize time in this stage and reach stage 3 as fast as possible. Stage 3 “Surgical anesthesia". During this stage, the skeletal muscles relax, and the patient's breathing becomes regular. Eye movements slow, then stop, and surgery can begin. It has been divided into 4 planes: 1. eyes initially rolling, then becoming fixed 2. loss of corneal and laryngeal reflexes 3. pupils dilate and loss of light reflex 4. intercostal paralysis, shallow abdominal respiration, dilated pupils Stage 4 Anesthesia, also known as "overdose", is the stage where too much medication has been given relative to the amount of surgical stimulation and the patient has severe brain stem or medullary depression. This results in a cessation of respiration and potential cardiovascular collapse. This stage is lethal without cardiovascular and respiratory support.

Answer 117

Person views ambiguous scenes of people, and is asked to describe various aspects of the scene (e.g. the person may be asked to describe what led up to this scene, the emotions of the characters, and what might happen afterwards). * A clinician will evaluate the following: descriptions, attempting to discover the conflicts, motivations and attitudes. * General guidelines to uncover expressed thoughts and described behaviors associated with a specific trait, e.g., the need for Achievement, which has a validated and reliable scoring system. * In the answers, the person "projects" their unconscious attitudes and motivations into the picture.

Answer 118

* Tourette’s -both multiple motor and at least one vocal tic * Persistent (chronic) motor or vocal tic disorder -single or multiple motor or vocal tics, but not both \*\*\*for above, 1 yr +, onset before 18yrs\*\*\* •provisional tic disorder -single or multiple motor or vocal tics present for less than a year Assessment •CBCL, SNAPfor tics —-\> MOVES, TSSS Treatment * impairing disorder treated first * psychoeducation * CBIT, HRT * psychopharmacology - alpha 2 adrenergics: clonidine, guanfacine - typical antipsychotics: haloperidol, pimozide SE - atypical antipsychotics: risperidone, aripiprazole not as many SE

Answer 119

* A nonfluent aphasia characterized by relatively good auditory comprehension and preserved repetition. Conversational speech is nonfluent, and patients make little attempt to produce speech spontaneously. In the acute stage, patients may be mute. When utterances are produced, usually after a long delay, they tend to be of reduced length (typically less than four words) and grammatical complexity. * Auditory comprehension is good for most conversational interaction, but there may be difficulty with complex syntax or multi-step commands. * Repetition is preserved in striking contrast to the virtual absence of spontaneous conversational speech. * Naming can be relatively preserved. * Lesion location. Lesions producing TcMA involve **extrasylvian regions of the left frontal lobe**. TcMA has also been described following **dorsolateral frontal lesions located anterior or superior to Broca’s area**. This is another lesion that causes the language area to be isolated. * Prognosis. TcMA may essentially resolve, or it may persist as relatively mild anomic aphasia.

Answer 120

* A fluent aphasia with impaired comprehension and preserved repetition. Conversational speech is fluent with relatively normal utterance length but semantic paraphasias, word-finding difficulties, and circumlocutions are common. * Auditory comprehension is significantly impaired, although usually not to the extent seen in Wernicke’s aphasia. * Repetition is surprisingly preserved, sometimes even for long complex utterances and unfamiliar words. * Naming is severely impaired. * Lesion location. TcSA most commonly results from **extrasylvian lesions involving the temporo-parietal-occipital region**, typically located posterior and deep to Wernicke’s area. This means that sensory information does not reach language areas. * Prognosis TcSA due to stroke may evolve to anomic aphasia. TcSA associated with dementing disease may progress to Wernicke’s aphasia over time and ultimately to global aphasia.

Answer 121

An emotional expectation that current relationships wil be similar to those experienced in childhood.

Answer 122

•There are more than 40 human diseases described that are due to unstable nucleotide repeats. Typically this instability is due to expansion of a stretch of trinucleotides, but unstable expansion of tetra-penta and hexa- nucleotides have also been described. Diseases with expanded CAG repeats are usually found in the coding region of the gene and results in expanded regions of polyglutamine in the protein. The polyglutamine expansion leads to protein misfolding. Because of the misfolded proteins, CAG repeat expansion results in degeneration of the CNS. As in other neurodegenerative diseases, the misfolded proteins aggregate and evade degradation by lysosomes. The misfolded proteins form intranuclear inclusions that are toxic, leading to degeneration of neurons. Some examples of Trinucleotide Repeat Expansion Disorders: * Fragile X syndrome (CGG triplet in familial mental retardation gene, most common genetic cause of mental retardation after Down syndrome) * Huntington's (CAG repeat) * Friedriech’s Ataxia (GAA repeat in gene encoding frataxin) * Spinocerebellar ataxia (CAG repeats in types 1,2,3,6,7,8, 10, 12 and 17

Answer 123

•Positive Punishment -and aversive event is added to a situation which decreases or weakens the behavior (scolding, spanking, shock)

Answer 124

•Negative Punishment - response cost or penalty training -a reinforcer is subtracted from the situation which decreases or weakens behavior (payinga fine for speeding, taking away privileges)

Answer 125

* objective * intelligence * norm referenced * criterion * objective

Answer 126

* The UWS is when a person is awake but showing no signs of awareness. On recovery from the coma state, UWS is characterized by the return of arousal without signs of awareness. (In contrast, a coma is a state that lacks both awareness and wakefulness.) * Absence of awareness can only be inferred by lack of responsiveness to the environment. We may not be able to determine lack of consciousness by behavioral measures. For this reason, the term ‘Unresponsive Wakefulness Syndrome’ (UWS) is a more accurate descriptive terms for Vegetative State. * A patient may open their eyes, wake up and fall asleep at regular intervals and have basic reflexes, such as blinking when they're startled by a loud noise, or withdrawing their hand when it's squeezed hard. However, a person in a vegetative state doesn't show any meaningful responses, such as following an object with their eyes or responding to voices. * They also show no signs of experiencing emotions nor of cognitive function. UWS patients' eyes might be in a relatively fixed position, may track moving objects (visual pursuit), or move in a completely unsynchronized manner. * Sleep-wake cycles may resume or patients may appear to be in a state of chronic wakefulness. They may grind their teeth, swallow, smile, shed tears, grunt, moan, or scream without any apparent external stimulus. UWS patients do not respond to sound, hunger, or pain. * Patients cannot obey verbal commands and lack local motor responses. Additionally, UWS patients cannot talk in comprehensible terms and may become noisy, restless, and hypermobile. * One of the most challenging tasks facing clinicians is that of differentiating UWS from minimally conscious (MCS) states

Answer 127

•it is possible to vary the time interval around some average •the length of the interval during which performing is not reinforced varies around some average •high steady run rates, higher than FI schedules, but not as high as FR and VR Ex: the nature photographer has to wait varying lengths of time to get the right shot

Answer 128

•the number of behaviors required for reinforcement varies around an average •ready performance at run rates similar to comparable FR schedules •PRPs are less often and shorter •hardest to extinguish Ex: a salesperson working on commission but not every effort results in a sale

Answer 129

* stepwise decline puctuated by periods of relative stability followed by abrupt declines * incremental impairment of memory and behavior initiation, extrapyramidal features - paucity of speecha nd motor activity, emotional incontinence, pseudobulbar palsy and rigidity * prominent fronta;/executive dysfunction early on and slow speed of information processing * lesslanguage impairment than in Alzheimer's

Answer 130

•a change in observer’s behavior due to model’s behavior and consequences •consequences of model’s behavior •consequences of observer’ s behavior •characteristics of model -observer’s age -attractiveness -observer’s learning history -emotional state •applications: therapy for phobia, can be used with biofeedback

Answer 131

IQ test yields Verbal, Performance, and Full-Scale IQ scores as well as individual subtest scores and factor index scores * Mean = 100, SD = 15 * Subtests Mean = 10, sd = 3 * Ages \>17

Answer 132

* A fluent aphasia with poor auditory comprehension and repetition. Conversational speech is fluent, easily articulated speech of relatively normal utterance length. Abundant semantic and phonemic paraphasias are present, as well as some neologisms. Utterances may be empty due to a lack of content words (nouns, verbs), an excess of grammatical words (e.g., articles, prepositions), and overuse of imprecise words (it, thing). Utterances may violate the rules of syntax and grammar, resulting in paragrammatic speech (e.g., “We need the thing in the over the house”). Verbal output may be excessive and rapid, with an apparent lack of inhibition of the flow of speech. * Auditory comprehension is severely impaired, even at the singleword level in many cases. Difficulty with complex syntax or multi-step commands is always present. Poor self-monitoring of their own speech may make patients surprisingly unaware of their inability to produce meaningful speech, and result in failure to attempt self-correction. * Repetition is significantly defective; patients may not be able to repeat even single words. * Naming attempts are often paraphasic, and severe anomia is the rule. * Lesion location. Wernicke’s aphasia is typically associated with **large posterior perisylvian lesions** **encompassing Wernicke’s area and often extending superiorly into the inferior parietal region**. * Prognosis. If auditory comprehension improves over time, the profile becomes more consistent with conduction aphasia. Other cases may evolve in the direction of TcSA.

Answer 133

Pick disease is an example of frontotemporal lobar degeneration. Grossly there is degeneration of the frontal and temporal lobes. Microscopically, these brains show Picks Bodies in the cerebral cortex and hippocampus. Pick bodies are intracytoplasmic, round inclusions containing tau protein. Other types of frontotemporal lobar degeneration have inclusions of TDP-43, an RNA binding protein that is also altered in amyotrophic lateral sclerosis.

Answer 134

Snoring is created by turbulent airflow vibrating upper airway soft tissue and is more prominent during inspiration. Persistent loud snoring is a classic symptom of obstructive sleep apnea syndrome (OSAS), but the absence of snoring does not exclude the diagnosis. Some patients' airways do not resonate to produce snoring.

Answer 135

Parkinson disease is an example of a movement disorder that is characterized clinically by tremor at rest, stooped posture, akinesia, rigidity, postural disequilibrium, slowness of voluntary movement and diminished facial expression. A similar clinical syndrome can occur from other diseases such as multiple system atrophy (striatonigral degeneration) or progressive supranuclear palsy. Parkinson disease is caused by degeneration of dopamine neurons in the substantia nigra. Grossly, the substantia nigra is pale due to the degeneration of neuromelanincontaining neurons. Microscopically, there are reduced neuromelanin-containing neurons in the substantia nigra and locus coeruleus. The Lewy Body is a hallmark of the disease. This is an eosinophilic inclusion found in the cytoplasm of remaining pigmented neurons of the substantia nigra and locus coeruleus. Lewy bodies contain aggregated filaments of α-synuclein. Alpha synuclein is a protein that is normally associated with synapses. Mutations of the α-synuclein gene have been described in familial cases of Parkinson Disease. A mainstay of treatment is with levodopa, the precursor of dopamine, which can cross the blood brain barrier. This treatment provides substantial improvement in the early phases; however, eventually patients do become refractory. In cases of Parkinson Disease with dementia, Lewy Bodies may be identified in the cerebral cortex. This is known as Dementia with Lewy Bodies or Diffuse Lewy Body Disease. In other patients who exhibit Parkinson with dementia, Alzheimer Disease (i.e. plaques and tangles in cortex) may coexist with Parkinson Disease.

Answer 136

ALS is a progressive neurodegenerative disease characterized by loss of upper motor neurons in the cerebral cortex and lower motor neurons in the spinal cord and brainstem. Clinically there is profound weakness of skeletal muscle and dysarthria and dysphagia secondary to involvement of cranial motor nuclei. Lower motor neuron involvement causes atrophy of tongue and skeletal muscle with fasciculations. Upper motor neuron involvement results in spasticity, hyperactive reflexes, clonus and the Babinski sign. There are typically no abnormalities of eye movement, no loss of bladder control or decreased sensation. Respiratory insufficiency leads to death. On microscopic sections of spinal cord, corticospinal tract degeneration can be seen. There is also prominent degeneration of motor neurons in the cerebral cortex, ventral horn of the spinal cord and the hypoglossal nucleus of the brainstem. TAR-DNA binding protein (TDP-43) is hyper-phosphorylated, abnormally folded and forms inclusions in motor neurons in ALS.

Answer 137

* Creutzfeldt-Jakob Disease * Gerstmann-Stroussler-Scheinker: Hereditary ataxia with cerebellar amyloid plaques * Fatal familial insomnia: Dementia following difficulty sleeping. This is the only prion disease that does not exhibit spongiform change. * Kuru: Subacute fatal disease of cerebellar degeneration with ataxia and dementia following ritualistic cannibalism * Variant Creutzfeldt-Jakob Disease

Answer 138

Bacteria can reach the brain from direct implantation (trauma), local extension (from mastoiditis or sinusitis) or by hematogenous spread (e.g. from endocarditis, pneumonia or an infected tooth). Acute bacterial (pyogenic) meningitis is a life threatening condition characterized by bacteria and acute inflammation in the subarachnoid space. Symptoms may include headache, photophobia, irritability, neck stiffness and clouding of consciousness. Grossly, the CSF looks cloudy and is under increased pressure. A spinal tap shows increased protein with markedly decreased glucose content. Untreated pyogenic meningitis can be fatal. Because the blood vessels are located in the subarachnoid space, a dreaded complication of acute meningitis is secondary vasculitis and brain infarcts. Another problem is the development of diffuse cerebral edema. Swelling of the brain will also compress the intracranial blood vessels producing generalized ischemia. Blockage of CSF reuptake into the arachnoid granulations will also raise intracranial pressure. With early and appropriate antibiotic treatment, complete recovery is possible. If significant scarring occurs in the subarachnoid space, however, hydrocephalus may be a long-term complication.

Answer 139

An abscess may be deadly because of significant mass effects. It is characterized by a necrotic center with pus, a rim of granulation tissue and surrounding fibrosis and edema. MRI will show a ring-enhancing lesion with edema. The abscess is one of the very few times in the brain that a fibrous scar forms rather than an astrocytic response (gliosis). As in other sites in the body, treatment involves drainage and antibiotics.

Answer 140

Viral infections usually include both brain parenchyma and the subarachnoid space (meningoencephalitis). Microscopically, viral encephalitis is characterized by perivascular lymphocytes infiltrates and microglial nodules. Microglial nodules are small foci of chronic inflammatory cells including microglial cells (identified by elongated nuclei), lymphocytes and reactive (gemistocytic) astrocytes. Some viruses produce characteristic inclusion bodies, but most often the microscopic appearance is nonspecific. Some viruses can produce exhibit striking tropism for a particular cell type. For example, poliovirus affects neurons in the grey matter in the spinal cord. Poliomyelitis causes paralysis because of necrosis of anterior horn motor neurons. Herpes simplex Type I (HSV-I) encephalitis causes a distinct gross appearance characterized by necrosis and hemorrhage of the temporal lobes. Microscopically there are perivascular inflammatory infiltrates, Cowdry type A intranuclear inclusions and the virus may be demonstrated using immunocytochemistry. This disease is commonly diagnosed by PCR of cerebrospinal fluid to detect viral DNA and can be treated using antiviral agents. In newborn infants, Herpes simplex type II is transmitted from maternal genital lesions and causes a diffuse necrotizing brain disease in addition to visceral necrosis.

Answer 141

The two major targets of HIV infection are the immune system and the central nervous system. Destruction of helper T cells expressing the CD4 receptor leads to profound immunodeficiency, the hallmark of AIDS. Immunodeficiency can lead to a wide variety of opportunistic infections in the central nervous system. These include cytomegalovirus, toxoplasmosis, atypical mycobacterium, cryptococcal meningitis, progressive multifocal leukoencephalopathy and others. In addition, immunosuppression may result in primary CNS lymphoma. The CD4 receptor that binds HIV is also present on the surface of the monocyte/macrophage series (including microglial cells), but these cells are relatively resistant to cell killing. The virus gains access through the brain via blood born monocytes, which then convert to macrophages in the tissue. The resistance to cell killing by the virus makes the macrophage an important reservoir of persistent virus in the central nervous system, even after antiviral treatment. HIV encephalitis is secondary to HIV infection of the CNS. HIV encephalitis, like other viral infections in the CNS, is characterized by a microglial nodules and perivascular lymphocytes. As distinctive finding in HIV encephalitis are macrophages that fuse to form multinucleated giant cells. These cells are commonly found in a perivascular location with lymphocytes. Brain atrophy, demyelination and white matter pallor may also be present. Immunohistochemical stains show the presence of HIV in the multinucleated giant cells and macrophages. The dementia that is associated with HIV infection is not explained by structural changes in the brain. Effective antiviral therapy has greatly decreased the incidence of neurological disease caused by HIV. However, HIV-associated cognitive disorders still occur, even after retroviral therapy. Although overt dementia is now rare, cognitive dysfunction secondary to HIV can still interfere with activities of daily life. The pathogenesis of this disorder is not understood, but is proposed to be due to the infection of HIV in the macrophages with secretion of inflammatory cytokines or HIV-derived proteins.

Answer 142

Fungal infections occur most commonly occur in immunocompromised patients. Common fungi for brain infections include aspergillus, candida, mucormycosis and cryptococcus. It tissue sections, it is useful to determine if the fungus exhibits yeast forms and/or hyphae. Further classification can be made on the morphological features of the hyphae (such as the angle of branching) or yeast (broad or narrow budding). When aspergillus is lodged in the cerebral vessels, it can directly invade blood vessels walls to gain access to the subarachnoid space (meningitis). Vascular thrombosis and vasculitis can obstruct the artery and lead to underlying infarction of the brain. Cryptococcal meningitis may be fulminant when occurring in the setting of AIDS, or may evolve over months or years in immune-competent individuals. It is very distinctive yeast with a polysaccharide capsule. This thick gelatinous capsule provides a mechanism to evade host defenses and results in gelatinous masses of fungi in the subarachnoid space, spreading into the brain around vessels in the Virchow-Robin spaces. Based on its appearance, this growth pattern has been described as producing soap bubbles.

Answer 143

An example of a protozoal infection is toxoplasmosis. Cerebral Toxoplasmosis is an opportunistic infection caused by Toxoplasma Gondii. Imaging typically shows multiple ring-enhancing lesions, however, a similar appearance occurs in immunocompromised patients with CNS lymphoma. Microscopically, toxoplasmosis is characterized by necrotic lesions surrounded by acute and chronic inflammation and macrophages. The diagnosis is made by the identification of tachyzoites (free) and bradyzoites (in cysts), Toxoplasma gondii has a complex life cycle with cats as the definitive host.

Answer 144

The four criteria for RLS consist of the patient noting an irresistible urge to move the legs that is worse with rest, more prominent in the evening and improved with movement. Patients may complain of unpleasant crawling, deep aching, or sensation of energy in the legs or arms, which causes the need for them to walk or have continuous movement of their limbs. Some patients note that their limbs move involuntarily. These complex symptoms may interfere with sleep onset, resulting in insomnia. Diagnostic criteria focusing on the main symptoms have been established. Patients with RLS may relay that the discomfort can be debilitating at times and even drive some individuals to pursue extreme measures. Certain chronic diseases and medical conditions, including iron deficiency, Parkinson’s disease, kidney failure, diabetes, and peripheral neuropathy often include symptoms of RLS. Treating these conditions often gives some relief from RLS symptoms. Periodic limb movements in sleep (PLMS) are found in most patients with RLS who are studied with polysomnography, but are more commonly associated without symptoms of RLS. Although most patients do not complain of symptoms related to the PLMS, patients or their bed partner may complain of leg or arm movements during sleep. PLMS are repetitive stereotyped movements of any of the extremities occurring as periodic events or appear random during NREM sleep. They are different from hypnic jerks (sleep starts), which are normal, nonperiodic, isolated myoclonic movements. Similar to RLS, periodic limb movements are provoked by uremia, anemia, peripheral neuropathy, antiemetics, antidepressants, and caffeine use. Dopamine agonists such as ropinirole and pramipexole have been approved for RLS and usually at doses smaller than those used for Parkinson disease. Levodopa plus benzerazide or carbidopa have been used, but patients often experience augmentation (earlier onset and increase in severity of RLS symptoms) or rebound symptoms in the morning; thus, this agent is not used frequently. For those individuals who have low iron, iron supplementation should be considered.

Answer 145

* enhance GABA A receptor activity * inhibition of NMDA glutamate receptor activity * enhance potassium channel activity

Answer 146

* decrease in systemic arterial blood pressure * decrease in sympathetic tone * decrease or complete loss of ventilatory drive and the reflexes that mainatin airway patency * hypothermia * nausea and vomiting - activation of chemoreceptor trigger zone and btainstem vomiting center, area postrema - rostral medulla very close to the obex

Answer 147

Diffuse astrocytoma

Answer 148

Anaplastic Astrocytoma

Answer 149

Glioblastoma with microvascular proliferation

Answer 150

Glioblastoma with pseudopalisading necrosis

Answer 151

Glioblastoma crossing the corpus callosum

Answer 152

Glioblastoma

Answer 153

Pilocytic Astrocytoma

Answer 154

Pilocytic Astrocytoma

Answer 155

Pilocytic Astrocytoma with Rosenthal fibers

Answer 156

Oligodendroglioma

Answer 157

Oligodendroglioma

Answer 158

Oligodendroglioma chicken wire formation

Answer 159

Oligodendroglioma Calcification

Answer 160

Ependymoma

Answer 161

Ependymoma withtrue rosettes

Answer 162

Ependymomam with perivascualr rosettes

Answer 163

Medulloblastoma

Answer 164

Medulloblastoma undifferentiated blue cell appearance

Answer 165

Medulloblastoma Homer Wright rosettes

Answer 166

Medulloblastoma subarachnoid spread

Answer 167

Meningioma

Answer 168

Meningioma

Answer 169

Meningioma whorls

Answer 170

Meningioma whorls

Answer 171

Meninigioma psamomma bodies

Answer 172

Meningioma with brain invasion (WHO Grade II)

Answer 173

Metastatic Carcinoma

Answer 174

Metastatic Cancer

Answer 175

Metastatic Cancer

Answer 176

Neurofibrillary tangles - Alzheimer's

Answer 177

neuroitic plaque and neurofibrillary tangle - Alzheimer's

Answer 178

neuritic plaque - Alzheminer's neuritic processes - fragments of axona and dendrites with tau amyloid core - beta amyloid peptide

Answer 179

amyloid beta peptide

Answer 180

frontotemporal lobar degeneration - Pick's

Answer 181

Normal vs. Parkinson's

Answer 182

Lewy Body - alpha synuclein

Answer 183

Lewy Body in Cortex - Lewy Body Dementia

Answer 184

ALS corticospinal tract degeneration

Answer 185

ALS - motor neuron degeneration

Answer 186

ALS - atrophy of ventral roots

Answer 187

ALS - neuronal inclusion misfolded TDP-43

Answer 188

spongiform change

Answer 189

spongiform change

Answer 190

prion ## Footnote * There is a normal endogenous prion protein * Infectious prion protein differs from normal by a conformational change (alpha helix to a beta pleated sheet). * The abnormal protein can covert other prion proteins into the abnormal conformation (propagation) * Aggregation and deposition damages brain tissue

Answer 191

spongiform change and amyloid plaques in new variant CJD

Answer 192

Bacterial Meningitis

Answer 193

Bacterial Meningitis

Answer 194

Bacterial Meningitis

Answer 195

* Neonates: **Group B streptococci; E. coli** * Infants and children: **Haemophilus influenzae (now \<2 / 100,000)** * Adolescents and young adults: **Neisseria meningitis** * Elderly: **Streptococcus pneumoniae**

Answer 196

polymorphonuclear lymphocytes - abscess

Answer 197

morphology of an abscess

Answer 198

viral encephalitis

Answer 199

viral encephalitis - microglial nodule

Answer 200

herpes encephalitis - prediliction for temporal lobe

Answer 201

herpes encephalitis

Answer 202

herpes encephalitis - perivascualr mononuclear cells, encephalitis and brain necrosis

Answer 203

herpes encephalitis - Cowdry Type A intranuclear inclusion

Answer 204

herpes encephalitis - long term sequelae

Answer 205

HIV encephalitis

Answer 206

HIV encephalitis - microglial nodule

Answer 207

HIV encephalitis - perivascular macrophages, multinucleated giant cells

Answer 208

HIV encephalitis - multinucleated giant cells site of HIV

Answer 209

fungal infection - cryptococcus

Answer 210

CNS Lymphoma - ring enhancing lesion

Answer 211

toxoplasmosis

Answer 212

primary CNS Lymphoma

Answer 213

toxoplasmosis

Answer 214

normal vs. Tay Sachs anterior horn motor neurons

Answer 215

metachromatic leukodystrophy

Answer 216

metachromatic leukodystrophy

Answer 217

metachromatic leukodystrophy - brown is stored material

Answer 218

Trinucleotide Repeat Expansion Disorder - Huntington's frontal lobe atrophy

Answer 219

normal vs. Huntington's

Answer 220

Huntington's Disease

Answer 221

Huntington's Disease - atrophy of caudate corresponds to severity of movement disorder

Answer 222

Huntington's Disease - loss of neurons and gliosis, huntingtin protein

Answer 223

plexiform neurofibroma

Answer 224

plexiform neurofibroma

Answer 225

neurofibromatosis 1

Answer 226

cutaneous neurofibromas

Answer 227

neurofibroma vs. malignant peripheral nerve sheath tumor

Answer 228

schwannoma

Answer 229

schwannoma

Answer 230

schwannoma

Answer 231

neurofibromatosis 1

Answer 232

neurofibromatosis 2 multiple meningiomas vestibular schwannomas and trigeminal schwannoma

Answer 233

* **Schwannoma** * benign tumor of Schwann cells * well circumscribed tumor attached to the nerve * commonly located on the vestibular nerve (CN VIII) * biphasic pattern of spindled and loose areas (Antoni A and B) * **Neurofibroma** * contains Schwann cells, fibroblasts, mast cells and axons * grows in (and incorporates) the nerve of origin * may form plexiform lesions in Neurofibromatosis * Has the potential to develop into malignant peripheral nerve sheath tumor * **Malignant Peripheral Nerve Sheath Tumor** * can arise in a neurofibroma or de novo

Answer 234

contusions

Answer 235

old contusion

Answer 236

diffuse axonal injury

Answer 237

diffuse axonal injury - axonal spheroids

Answer 238

CTE - tau positive tangles

Answer 239

traumatic dissection of vertebral artery