____________ arise from chromaffin cells in the adrenal medulla, which is derived from neural crest cells.
Pheochromocytomas
Neurocutaneous disorders (phakomatoses) are characterized by involvement of structures derived from what embryonic layer?
the embryonic ectoderm (central nervous system, skin, and eyes).
What disease/finding in a young child is highly suspicious (nearly 100% specific) for tuberous sclerosis?
cardiac rhabdomyoma
What degenerative ocular disease is commonly misdiagnosed as Parkinson’s?
Parkinson disease can sometimes be confused with progressive supranuclear palsy.
Progressive supranuclear palsy usually presents as an isolated vertical gaze palsy, followed by paresis of other ocular movements, and signs and symptoms of Parkinsonism (ie, tremor, bradykinesia, rigidity, and postural instability).
What drug combo decreases dopamine breakdown in pt. with parkinsons diz?
Selegiline (MAO-inhibitor) + COMT inhibitor (e.g. entacapone or tolcapone) leads to decreased dopamine breakdown. Entacapone is a peripheral COMT inhibitor while tolcapone is a central and peripheral COMT inhibitor.
What drugs can be used to treat Parkinson disease leading to decreased tremor and rigidity?
Antimuscarinics like Benztropine can also be used to treat Parkinson disease leading to decreased tremor and rigidity (mnemonic: Park your Mercedes-Benz).
Neuroblastoma is the most common tumor of the adrenal medulla in children, and it frequently results from amplification of what?
N-myc oncogene.
Do oligodendrogliomas contain Psammoma bodies?
NO!!!
Where do oligodendrogliomas tend to occur and what do oligodendrogliomas look like on histology?
Cerebral Hemisphere of middle aged people; may present with siezures Sx.
Histo: large, round nuclei with a clear lao of cytoplasm “FRIED EGG” cells.
What are psammoma bodies?
lamellated mineral deposits formed via calcification of whorled clusters of cells found inside the tumor.
Psammoma bodies are associated with what neoplasms?
meningioma, papillary adenocarcinoma of the thyroid, ovarian serous papillary cystadenocarcinoma, and mesothelioma (mnemonic: PSaMMoma (Papillary [thyroid], Serous [ovary], Meningioma, Mesothelioma).
What are Meningiomas, the 2nd most common type of primary brain tumor? Where are they located?
Meningiomas arise from arachnoid cells external to the brain.
frequently occur in the convexities of cerebral hemispheres and in the parasagittal regions.
What findings are ~w/ Neurofibromatosis type 1 (NF-1)?
A helpful mnemonic for the NF1 is: CAFE SPOT:
Café-au-lait spots Axillary freckling (and inguinal) Fibroma Eye) lisch nodule Scoliosis or other skeletal abnormality Pheochromocytoma OT optic tumor (glioma).
A defect in excision of thymidine dimers is the cause of _______________, an autosomal-recessive disorder that predisposes individuals to melanomas and basal and squamous cell carcinomas. Because of the inability to repair ultraviolet-induced DNA damage, deleterious mutations lead to frequent skin malignancies.
xeroderma pigmentosum
Medial longitudinal fasciculus syndrome is characteristic of _____________. It leads to palsy of the ipsilateral medial rectus.
multiple sclerosis
Medial longitudinal fasciculus syndrome is characteristic of multiple sclerosis. It leads to palsy of the ______________.
ipsilateral medial rectus.
Dissection or thrombosis of the posterior inferior cerebellar artery classically results in _____________________.
lateral medullary syndrome.
Manifestations include ipsilateral Horner syndrome, absent pain and temperature sensation on the ipsilateral face and contralateral body, and ataxia.
_____________ is a manifestation of a lesion to the nondominant parietal lobe of the cerebral cortex
Hemineglect
Deviation of the tongue indicates damage to the __________ nucleus
hypoglossal
What are periodic acid–Schiff-positive cytoplasmic inclusions that are remnants of autophagic vacuoles called?
What disease process are they associated with?
Bunina bodies
ALS
These are found in the neurons of patients with amyotrophic lateral sclerosis, not the muscle. This image of a neuron containing Bunina bodies was produced using ubiquitin immunohistocemistry.
What neuromuscular disease will show small angulated muscle fibers on muscle biopsy?
ALSA
muscle biopsy specimen (like that shown here) would reveal muscular atrophy due to lack of neuronal input. Atrophy is defined as a decrease in preexisting cell mass; atrophy with severe fatty replacement.
What is the func. of the golgi tendon organs?
Muscle preconception
Group B streptococci is one of the leading causes of newborn meningitis. After an episode of meningitis has resolved, meningeal scarring can occur as a complication.
What can result from this?
Communicating (non-obstructive) hydrocephalus.
d/t decrease absorption of CSF by the arachnoid villi
What is the MOA of a drug that is used to improve cognitive measures in pt. with Alzheimer’s?
donepezil (a cholinesterase inhibitor/indirect cholinomimetic) improves cognitive measures by upregulating acetylcholine activity. Donepezil, however, does not alter the course of the disease.
The ____1____ nerve arises from S2–S4 of the sacral plexus and innervates the structures of the ___________2___________.
- pudendal
2. perineum, including sensation of the genitalia
What are the Motor functions of the pudendal nerve?
voluntary urinary and fecal continence, and contraction of pelvic and urogenital diaphragms to support pelvic viscera.
What are the motor and sensory innervation of the Ulnar nerve?
the ulnar nerve innervates the hypothenar muscles, two of the lumbrical muscles, and all of the interosseous muscles; also, it gives off two sensory branches: (1) the palmar cutaneous branch and (2) the dorsal cutaneous branch, which supplies the skin over the hypothenar eminence, and the dorsal ulnar aspect of the hand, respectively.
Left inferior frontal gyrus = ?
Broca’s area (BA 44)
Left Superior temporal gyrus = ?
Weernicke’s area (BA 22)
What makes up the BBB?
Complex of:
endothelial cells
pericytes
astrocyte foot processes
Proximal portion of the basilar membrane is responsible for hearing what frequency of sound?
HIGH!
thinnest and least compliant part of the basilar membrane.
Resting Tremor + bradykinesia (slow movements) == ?
Parkinsons
Parkinson disease is associated with increased muscle tone, cogwheel rigidity, and postural instability. It is a movement disorder caused by the degeneration of the pars compacta region of the substantia nigra, resulting in decreased dopaminergic stimulation of the direct excitatory pathway of the basal ganglia.
accumulation of α-synuclein deposits leading to cytoplasmic inclusions (Lewy bodies) are often seen in pathologic specimens from patients with what disease?
Parkinsons
history of menstrual irregularities, cold intolerance, and constipation suggests multiple endocrine disorders that can be attributed to dysfunction of the anterior pituitary, is ~w/ what ophthalmic issue?
Bitemporal Hemianopia
d/t compression of the optic chiasm
What are the physical manifestations of cerebellar lesions?
including loss of coordination (ataxia), hypotonia, intention tremor, and instability (patients feel they are going to fall toward the side of their lesion)
What disease involves inflammation and demyelination of peripheral nerves.
Guillain-Barré syndrome (GBS)
GBS also has been associated with systemic diseases such as Hodgkin lymphoma, systemic lupus erythematosus, sarcoidosis, Lyme disease, and infection with Epstein-Barr virus, cytomegalovirus, herpes simplex virus, and HIV.
MS is ~w/ what HLA?
HLA-DR2
What is a S/Sx that is seen in the early stages of MS?
Sudden vision loss
MRI demonstrating periventricular white matter lesions (plaques) & alevated oligoclonal bands in the cerebrospinal fluid are highly suggestive of what?
MS
Are Fasciculations ~w/ UMN or LMN?
LMN
Weakness, atrophy, fasciculations, decrease reflexes, decrease muscle tone and faccid paralysis = ?
LMN lesion
Protein aggregates and neuronal death in the caudate nucleus = ?
Huntingtons
CAG
Gerstmann syndrome is a neurologic disorder characterized by four primary symptoms:
(1) Writing disability exhibited as inability to write known as agraphia
(2) Lack of understanding the rules for calculation or arithmetic known as acalculia
(3) Inability to identify fingers known as finger agnosia
(4) Inability to distinguish right from left is termed right-left disorientation
damage to the lateral forearm suggests injury to the ___________ nerve
musculocutaneous;
also will have an absent biceps reflex (C5)
What sign is associated with internal malignancies such as colorectal, stomach, liver, or pancreatic cancers.
Leser-Trélat sign
what are the skin manifestation of Gastric cancer?
Skin manifestations of gastric cancer include acanthosis nigricans and Leser-Trélat sign, which is the sudden eruption of multiple seborrheic keratoses
___________ is characterized by physical restlessness, difficulty sitting still, and a compelling need to move.
Akathisia
Drug-induced parkinsonism manifests as?
tremor, bradykinesia, and cogwheel rigidity.
The superior laryngeal artery accompanies the internal branch of what nerve in the larynx?
superior laryngeal nerve
A lesion of this nerve can lead to loss of sensation in the laryngeal mucosa above the vocal folds and loss of the cough reflex.
Pt. is unable to look up, but the rest of the eye movements are normal. Compression of what structure is responsible?
Superior colliculus; this is Parinaud syndrome
What can lead to defects in vertical gaze, near-light dissociation, and noncommunicating hydrocephalus because of compression of the cerebral aqueduct.
Parinaud syndrome
Parinaud syndrome is caused by a lesion in what?
dorsal midbrain.
____________ cells give rise to neuroglial cells including astrocytes and oligodendrocytes.
Neuroectoderm
what cells do schwann cells and pigment cells come from?
NCC
What nerve is a branch of the vagus nerve that innervates all of the intrinsic laryngeal muscles except the cricothyroid muscle?
The recurrent laryngeal
The recurrent laryngeal nerve is a branch of the vagus nerve that innervates all of the intrinsic laryngeal muscles except the __________ muscle.
cricothyroid
The cricothyroid muscle is innervated by what?
the external branch of the superior laryngeal nerve.
the external branch of the superior laryngeal nerve innervates what muscle?
cricothyroid muscle
What is the MCC eye tumor of childhood?
Retinoblastoma;
caused by mutations in RB1 gene on chromosome 13q
mmc eye tumor in peds that looks to reveals small, round, primitive-appearing blue cells; may have rosettes.
Retinoblastoma
Familial retinoblastoma: bilateral eye tumors, associated with what other tumor?
osteosarcoma
The pituitary can be approached transnasally via the _________ sinus for hypophysectomy.
sphenoid
What are the 4 functions of the CN3?
CN3 = Oculomotor nerve
- Constricts pupil (sphincter pupillae)
- Accommodates (focus for near vision; ciliary muscle)
- Innervates extraocular muscles (medial rectus, superior rectus, inferior rectus, inferior oblique). Adduction (looking toward the nose, medial rectus) is the most important function.
- Raises eyelid (levator palpebrae)
Oculomotor lesions can result in: (5)
Oculomotor lesions can result in:
I- nability to adduct the eye (leading to horizontal diplopia)
- Mydriasis
- Ptosis
- Inability to constrict the eye
- Loss of accommodation
What type of seizure typically presents as staring blankly into space for a few seconds?
Absence seizure typically presents as staring blankly into space for a few seconds.
What brain structure is sensitive to anoxic injury and can be selectively affected, leading to a deficit in the ability to form new memories?
Hippocampus; involved in the formation of new memories.
The caudate and putamen together are called what?
~w/ what disease?
Striatum or neo-striatum
HUNTINGTONS
Facial nerve (CN VII) lesion leads to what defects? (6)
Facial nerve (CN VII) lesion:
- Paralysis of muscles of facial expression (including the orbicularis oculi)
- Hyperacusis (caused by paralysis of the stapedius muscle)
- Loss of taste from the anterior two-thirds of the tongue
- Loss of corneal reflex (efferent limb)
- Deficits in salivation (submandibular and sublingual glands)
- Lacrimal gland dysfunction
In unilateral (left) facial paralysis due to a lesion of the facial nerve (CN VII; Bell’s palsy).
Lower motor neuron lesions of CN VII affect what?
Upper motor neuron lesions causes what?
Lower motor neuron lesions of CN VII affect the entire ipsilateral half of the face and
upper motor neuron lesions cause contralateral symptoms that spare the forehead,
The median nerve of the arms/hands, passes thru what forearm muscle?
Pronator teres
The musculocutaneous nerve passes thru what forearm muscle?
Coracobrachialis
The ulnar nerve passes thru what forearm muscle?
Flexor carpi ulnaris
The radial nerve passes thru what forearm muscle?
Supinator
What nerve emerges from the interpeduncular fossa of the midbrain and then passes between the superior cerebellar artery and the posterior cerebral artery immediately lateral to the basilar artery.
The oculomotor nerve (CN III)
The oculomotor nerve (CN III) emerges from the interpeduncular fossa of the midbrain and then passes between what arteries?
superior cerebellar artery and the posterior cerebral artery immediately lateral to the basilar artery.
Compression of CN III by an adjacent aneurysm can result in the inability to do what?
adduct that eye
Craniopharyngioma is from what embryological structure?
Rathke’s pouch;
tumors cells look like cells of tooth enamel, b/c of similar embryo.
Symptoms due to encroachment on pituitary stalk or optic chiasm
What is visual agnosia?
You can see objects, but you CANNOT recognize or tell what they are.
What lesion is ~w/ visual agnosia?
lesions in the Temporo-Occipital association cortex (the “what” pathway/ Ventral Pathway)
What brain pathway analyzes spatial relationships between objects, between the body and visual stimuli, and motion?
The dorsal pathway, or the “where” pathway projects to parieto-occipital association cortex
(cortex that bridges the occipital and parietal lobes)
Where does CNV2 exit?
Foramen Rotundum
A useful mnemonic for the foramina through which the branches of the trigeminal nerve leave the skull is “SRO”—or “Standing Room Only”—for V1 to V3:
Superior orbital fissure—V1
Foramen Rotundum—V2
Foramen Ovale—V3
HSV-1 can remain latent in what part of the nervous system?
Trigeminal Ganglion
What does bacterial abscesses in the brain look like on CT?
Ring-Enhancing!!
Bacterial abscesses in the brain do NOT present with nuchal rigidity.
What is the mcc of crain abscesses in peds?
recurrent episodes of otitis media
A astrocytic tumor that grows from the walls of the lateral ventricles, and contains the large ganglioid cells is called?
Sub-ependymal Giant Cells Astrocytoma.
It is pathognomonic of tuberous sclerosis, which is caused by mutations of the TSC1 or TSC2 genes
The following are ~w/ what disease?
- Autosomal dominant
- Facial lesions (adenoma sebaceum)
- Hypopigmented “ash-leaf” spots on the skin
- Multiple hamartomas, including cortical tubers
- Renal angiomyolipomas
- Cardiac rhabdomyomas
- Astrocytomas
- Subependymal giant cell astrocytoma
Tuberous sclerosis:
Bilateral Schwannomas of the 8th cranial nerve is ~w/ what ?
NF2
small, pigmented, nodular lesions of a hamartomatous nature that are present in patients who have ???
neurofibromatosis type 1; there are called Lisch Nodules.
Other features of NF1 include café-au-lait spots, axillary freckling, neurofibromas, scoliosis, pheochromocytoma, and optic gliomas.
The follwoing is ~w/…
- Hemandtioblastoma
- Renal cell carcinomas
- pheochromocytomas
VHL; chr. 3 [AD]
Café-au-lait spots (choice A) are pigmented macules of the skin found in both types of neurofibromatosis.; and can also be seen in what other syndrome?
McCune-Albright syndrome
The chemoreceptor trigger zone (CTZ), which causes vomiting, is located in the __________ on the floor of the fourth ventricle.
area postrema
The ___________ zone, which causes vomiting, is located in the area postrema on the floor of the fourth ventricle.
chemoreceptor trigger zone (CTZ)
The chemoreceptor trigger zone (CTZ), which causes vomiting, is located in the area postrema on the floor of the ____________.
fourth ventricle
___________ lies just lateral to the floor of the rostral part of the fourth ventricle. Cells in this nucleus synthesize norepinephrine, and involved in the control of cortical activation (arousal).
Locus coeruleus
Locus coeruleus lies just lateral to the floor of the rostral part of the fourth ventricle. Cells in this nucleus synthesize __________ , and involved in the control of cortical activation (arousal).
norepinephrine
The floor of the third ventricle contains the ________________ , with temperature regulation, feeding centers, pituitary control, and other regulatory functions, but has no significant role in vomiting.
hypothalamus
Corneal reflex:
Afferent limb: ?
Efferent limb: ?
Corneal reflex:
Afferent limb of the corneal blink reflex is by ipsilateral CN V.
Efferent limb of the corneal blink reflex is by bilateral CN VII.
Adduction of the left eye is controlled by the _________ nerve via the action of the medial rectus.
oculomotor nerve (CN III)
Adduction of the left eye is controlled by the oculomotor nerve (CN III) via the action of the _______ muscle.
medial rectus m.
Sensory innervation to the anterior half of the external ear canal is supplied by the __________ nerve, which also supplies the facial surface of the upper part of the auricle.
auriculotemporal nerve of the Mandibular br. of the Trigeminal nerve.
CNV_3
Loss of knee flexion, foot dorsiflexion, and weak extension of the thigh == what nerve?
Sciatic n.
Sensory Loss= posterior thigh, leg, and foot
Loss of ABduction of the limb; Trendelenburg gait == what nerve?
Superior Gluteal nerve.
Weakness of hip extension and lateral rotation of the thigh = what nerve?
INFERIOR gluteal n.
A useful mnemonic for Patau syndrome is M1CRoCePHaly:
Mental retardation, 13 chromosome, Cardiac defects, Renal defects, Cleft lip & palate, Polydactyly, Holoprosencephaly.
________________ is a form of neural tube defect, associated with folate deficiency, and is characterized by complete failure of higher brain structures to develop.
Anencephaly
What is lissencephaly?
is a forebrain anomaly, characterized by the absence of cortical gyri. Grossly, the fetal cortex has a smooth surface and lacks the normal gyri.
Various motor and sensory deficits separated in space and time == ?
MS; unmistakable appearance of well-demarcated areas of demyelination of the white matter.
Shine light in Marcus Gunn pupil ⇒ pupils do not constrict fully
Shine light in normal eye ⇒ pupils constrict fully
Shine light in affected pupil again ⇒ ??
apparent dilation of both pupils because the stimulus carried by the optic nerve (CN II) of the affected eye is weaker than the normal eye.
pathologic features in the brain include microglial nodules, with multinucleated giant cells is ~w/ what?
HIV encephalitis
round intracytoplasmic neuronal inclusions that contain alpha-synuclein in the substantia nigra and neocortex ==?
Lewy bodies.
What etiologic agent is a negative-sense single-stranded RNA virus transmitted to humans by animal bite and what is the classic histo?
Rabies. Elongated intracytoplasmic neuronal inclusions (Negri bodies)
MRI in patients with MS can show ____1____ lesions on T1 weighted images, but ____2____ lesions on T2 weighted images
- hypointense
2. hyperintense
older plaques show hyperplasia and hypertrophy of astrocytes transform the plaque into a gliotic area, in which axons are relatively preserved but oligodendroglial cells are greatly diminished is known as what?
Gliosis.
What is the classic cause of CHRONIC bacterial meningitis?
Mycobacterium tuberculosis; CSF shows lymphocytes, plasma cells, and macrophages; decrease glucose, elevated protein.
arylsulfatase A (cerebroside sulfatase in leukocytes ==> ?
Metachromatic leukodystrophy. ataxia, central and peripheral demyelination, dementia, and occasional optic atrophy. Onset during infancy typically predicts poorer prognosis compared to onset during adolescence and adulthood.
accumulation of galactocerebroside. Classic features include peripheral neuropathy, developmental delay, optic atrophy, and globoid cells (multinucleated cells) at sites of disease. == ??
Krabbe disease
Diffuse atrophy with prominent sulci == ??
alzheimers
evidence of intraventricular blood is typical for what?
Subarachnoid hemorrhage.
A “lens-shaped” (biconvex) hematoma ==?
Epidural; do NOT cross sutulre lines. bleed from middle meningeal a. ~w/ skull fracture and “LUCENT PERIOD”.
hematoma that extendes across suture lines = ?
Subdural hematoma: Sx present days-weeks after injury. d/t trauma to the bridging vessels. CRESCENT-Shaped.
Sx of bilateral papilledema, n/v, nuchal rigidity, and mental status changes ==?
increased ICP. like in the tumor “filling the 4th ventricle” which blocks the circulation of CSF causing non-comm hydrocephalus.
“filling the 4th ventricle” == ??
obstruction causing non-communicating hydrocephalus.
subependymal nodules (swollen glial cells and multinucleated cells), cardiac rhabdomyoma, cortical and retinal hamartoma (non-neoplastic growths consisting of disorganized local tissue), renal angiomyolipoma, adenoma sebaceum (red angiofibroma of the face- confused with acne), ash-leaf spots (hypomelanotic skin macules), giant-cell astrocytomas, and intellectual disability/seizures.
???
Tuberous sclerosis
retinal hemanigoblastomas, bilateral RCC, retinal hemangioblastomas == ?
Von Hippel-Lindau
Granulovacuolar degeneration and Hirano bodies & neurofibilary tangles ==?
Alzheimer’s; neurofibilary tangles = hyperphos. tau protein.
Occlusion of What artery (dominant hemisphere) results in:
Broca aphasia.
Spastic paresis of the contralateral lower face and upper limb.
Anesthesia of contralateral face and upper limb.
left middle cerebral artery
is a structural disorder in which a cavity (syrinx) forms within the spinal cord. It classically leads to a cape-like loss of pain and temperature sensation due to damage to decussating spinothalamic fibers (not simply demyelination) in the anterior white commissure.== ???
Syringomyelia
bowel/bladder/sexual dysfunction can be a late presentation of what neurological syndrome?
Horner’s syndrome
Post infection, an autoimmune attack on the myelin of peripheral nerves (Schwann cells). == ?
GBS, smilar pathophysiology to MS.
Pt. with Alzheimer disease are at in risk for what type of brain hemorrhage?
“Lobar” hemorrhage, b/c cerebral amyloid angiopathy makes vessels weak and prone to rupture.
What type of brain aneurysm might cause a sudden hemorrhage within the basal ganglia and brainstem; and are primarily seen in patients with severe hypertension?
rupture of a Charco-Bouchard aneurysm
multifocal lymphohistiocytic infiltrates with numerous microglial nodules and scattered multinucleated giant cells. ==?
HIV encephalopathy. IHC stain will show positive p24 antigen within affected microglial and multinucleated cells.
MRI shows multifocal nonenhancing lesions in white matter without mass effect; mild cortical atrophy may be seen. ==?
progressive multifocal leukoencephalopathy (PML); d/t JC virus.
in 50yo. pt., CT scan shows hyperostosis of the skull and an intracranial mass, whirling patterns and psammoma bodies == what brain tumor?
meningioma
usually caused by trauma, rupture of bridging veins = ?
Subdrual hematoma
usually traumatic, rupture of middle meningeal a. after a skull fracture, lucid interval before LOC == ?
Epidural hematoma.
mmc rupture of berry aneurysm
SAH
worst headache of my life, ~w/ Marfans, ehlers-danlos, adult polycystic kidney disease, HTN and Smoking.
SAH; ~w/ weak blood vessels.
common visual defect in pt. with Wernicke aphasia?
right upper quadrantanopia; “pie-in-the-sky”. d/t to fucked temporal lobe.
Patients with Wernicke aphasia cannot comprehend spoken language and have fluent verbalization that lacks meaning (“word salad”). Reading and writing are similarly affected.
Fuck temporal lobe = what visual defect?
right upper quadrantanopia; “pie-in-the-sky”
Histologic features include: loss of pigmented dopaminergic neurons from the substantia nigra and Lewy bodies (intracytoplasmic eosinophilic inclusions).
what disease?
Parkinsons
Granulovacuolar degeneration and Hirano bodies are intracytoplasmic inclusions that are classically found in hippocampal pyramidal neurons of what patients?
Alzheimer disease (but can also be found in intellectually intact elderly people)
microglial nodules found in what?
viral encephalitis
seizures characterized by quick, repetitive jerks =?
myoclonic seizures
brain mass that have atypical cells that stains positive for s100 and HMB45 = ?
metastatic melanoma.
Multiple masses located at the gray-white matter junction is highly suggestive of what?
metastatic disease. The gray-white junction is not only highly vascular, but many of these vessels are of narrow caliber, thus metastatic cells can easily lodge in these spaces.
What develops as a saccular expansion of the arterial wall and most commonly affects the anterior part of the circle of Willis, including the anterior cerebral artery (ACA) close to where the anterior communicating artery branches off.
rupture of a berry aneurysm leading to a SAH. ~w/ pt. with ADPKD.
What causes Treacher-Collin’s syndrome?
Failure of development of 1st and 2nd pharyngeal arches/neural crest cells fail to migrate
How does treacher-collins syndrome present?
craniofacial abnormalities that cause feeding difficulties/airway compromise; conductive hearing loss (incus/malleus/stapes)
What molecules are derived from the polypeptide molecule POMC and what does this mean?
ACTH, MSH, Beta-endorphins; there is a relationship between the stress axis and the opioid system
What mutated genes can be implicated in parkinson’s?
Parkin, PINK-1, DJ-1
What molecule is needed for ubiquitin to work?
ATP
What area gets cystic degeneration in Wilson’s?
Putamen
What is first line treatment for serotonin syndrome?
Cyproheptadine; histamine antagonist with nonspecific 5HT-1/2 receptor antagonism
What is first line treatment for serotonin syndrome?
Cyproheptadine; histamine antagonist with nonspecific 5HT-1/2 receptor antagonism
Aneurysm at which artery causes CN III palsy?
P-Comm; mydriasis (damaged parasympathetic efferent), down and out eye and ptosis (levator palpebrae superioris issue)
Where is the lesion in Internuclear ophthalmoplegia?
ipsilateral MLF/ipsilateral dorsal pons; contralateral eye abducts with nystagmus
increase N-myc copies = ?
neuroblastoma; increase urine catecholamines
Conduction aphasia location:
arcuate Fascisulus; Conduction aphasia: can’t do repetition.
to have the patient draw a clock is to test what?
executive function
Failure of the rostral neuropore to fuse?
anencephaly
Failure of caudal neuropore to fuse?
spina bifida
Why do you hyperventilate patients with elevated ICP?
Because decreased PaCO2 leads to vasoconstriction of the cerebral vessels–> decreased ICP
If a patient has rheumatoid arthritis that affects the cervical spine, then what are they at risk for?
Increased risk of subluxation of the atlantoaxial joint
Increased risk of subluxation of the atlantoaxial joint ~w/ what disease?
RA
Chorioretinitis, hydrocephalus, and intracranial calcifications = ?
congential toxoplasmosis
Compression due to pelvic trauma, surgery or cancer (bladder cancer) d/t?
obturator n. injury
Miosis, bradycardia, hypotension, bradypnea, decreased bowel sounds = ?
opioid OD
What eye manifestation can atropine worsen?
Acute angle-closure galucoma; leads to mydriasis which narrows the anterior chamber of the eye–> decreased aqueous humor outflow
It’s pigmented; posterior rostral pons near the lateral floor of the fourth ventricle
Locus Ceruleus
What nerves/vein exit through the superior orbital fissure?
Occulomotor III, Opthalmic (V1), Trochlear (IV), Abducens (VI), Superior ophthalmic vein
What nerves are involved in the corneal blink reflex?
Sensory limb is the nasociliary branch of trigeminal CNV1.
Motor limb is the temporal branch of Facial CNVII
How does a pineal gland tumor present?
Sensory limb is the nasociliary branch of trigeminal CNV1
Motor limb is the temporal branch of Facial CNVII
What are the symptoms of Parinaud Syndrome (Dorsal Midbrain)?
upward gaze palsy, bilateral eyelid retraction, light near dissociation (pupils that react to accommodation, but not to light)
What are the 3 brain areas most susceptible to ischemic injury?
Pyramidal cells of the hippocampus/neocortex and purkinje cells of the cerebellum
Horizontal nystagmus/bilateral abducens palsy/opthalmoplegia, ataxia, AMS, are S/Sx of what?
Wernicke-Korsakoff syndrome
Fever, Rhabdomyolysis, Parkinsonism, hypertension, tachycardia are S/Sx of what?
Neuroleptic Malignant Syndrome
Dopamine agonist ergot?
bromocriptine
How does phenytoin cause gingival hyperplasia?
increased expression of platelet derived growth factor; also causes megaloblastic anemia due to interference with folic acid metabolism.
What can get damaged in patient that supinate/pronate a lot (ie they are using screwdrivers)?
Radial nerve
compression of CNIII with dilated pupils; also decorticate/dcerebrate posturing and lost of vestibulo-ocular reflexes are S/Sx of what?
Uncal herniation
Injury of ulnar nerve at the elbow causes what deformity/weaknesses?
Ulnar claw; weakness of flexion/adduction of the wrist, abduction/adduction of the fingers, weakness of flexion of 4th and 5th digits
What is the primary cause of lacunar infarcts?
Lipohyalinosis/microatheroma formation
Most common cause of aseptic meningitis?
Enteroviruses (Coxsackie virus)
Where are circadian rhythms maintained?
Suprachiasmatic nucleus; melatonin
Right MCA stroke?
Left MCA stroke?
Right MCA stroke?
Left facial/extremity weakness (lower limb is usually less affected)
Left MCA stroke?
Right facial/extremity weakness with aphasia
What nerve can be damaged in an appendectomy?
Iliohypogastric; decreased suprapubic/gluteal sensation and anterolateral abdominal motor dysfunction
What type of receptors are mu-opioid receptors?
Gi
What nerve is affected by crutch palsy?
Radial nerve
Mass in temporal lobe will cause what?
Homonymous superior quandrantanopia (Meyer’s loop)
Stroke in the Subthalamic nucleus leads to what?
Contralateral hemiballismus (caused by lacunar stroke)
Where are cutaneous neurofibromas derived from?
Schwann cells/neural crest cells
What is the primary virulence factor of E. Coli in Meningitis?
K1 Capsule (prevents phagocytosis)
Adverse effects of carbamazepine?
agranulocytosis, SIADH
What is the lngth constant of a nerve?
measure of how far along an axon an electrical impulse can propgate; demyelination decreases length constant.
An interscalene nerve block usually causes paralysis of what nerve?
ipsilateral phrenic n.
Where does CN VIII exit?
Cerebellopontine angle
3 Hz spike-wave complexes superimposed on normal background activity = ?
Absence seizures
What is the most common physical exam finding in patients with PCA infarction?
Contralateral Homonymous Hemianopia with macular sparing (also thalamus symptoms)
What can be seen with an internal capsule stroke?
pure UPN signs contralaterally
ADRs of inhaled anesthetics:
bradycardia/decreased CO hypoventilation Increased cerebral perfusion Decreased GFR decreased hepatic perfusion
What enzymes is Vitamin B1 a cofactor for? (4)
- Pyruvate Dehydrogenase
- Alpha ketoglutarate dehydrogenase
- Branched chain ketoacid dehydrogenase
- Transkelotase (pentose phosphate pathway)
Vascular malformation of dilated blood vessels that can compress brain structures and cause seizures/neuro deficits ==?
cavernous hemagioma
Why do people with MS feel fatigued after taking a hot shower?
b/c heat decreases axonal transmission
What CN are affected in Cavernous Sinus Thrombosis?
III, IV, V (Ophthalmic and maxillary branches), VI
What visual field defects do macular lesions cause?
Central Scotomas
Pathophys of Macular degeneration?
Drusen/lipid deposition behind the retina and neovascularization of the retina
What beta receptor is found in the uterus/what is the effect of a Beta agonist in this case?
[B2]; relaxation (tocolysis)
What is a gross brain finding in PKU?
Pallor in areas of catecholamine synthesis (Substantia nigra, locus ceruleus, vagal nucleus dorsalis (makes neuromelanin)
PICA ischemia Deficits (Lateral Medullary Syndrome)
Ipsilateral horner’s syndrome, ipsilateral facial loss of pain/temp, contralateral body loss of pain/temp, nystagmus/vertigo, romberg sign (fall to side of the lesion), bulbar symptoms (dysphagia/hoarseness)
What is a common hearing finding in Bell’s palsy?
Hyperacusis (sensitivity to hearing noises); because facial nerve innervates the stapedius nerve/muscle
What can cause unilateral nasal hemaniopsia?
Internal carotid aneurysm compressing the lateral optic chiasm
What are three weird things that can be seen with bell’s palsy?
Decreased lacrimation, decreased taste over ant 2/3 of tongue, hyperacusis.
What can be seen years after an ischemic stroke?
Persistent myelin debris
What biochemical disturbance is present in patients with Alzheimer’s?
Decreased choline acetyltransferase–? decreased acetylcholine in the Hippocampus and Basal Nucleus of Meynert
Intracranial Schwannomas arose from where? What nerves can be compressed by an intracranial schwannoma?
Cerebello-pontine angle. CN V, CN VII, CN VIII
How does Argninase Deficiency Present?
Spastic diplegia, growth delay, and abnormal movements
Damage to the brainstem AT OR BELOW the level of the Red Nucleus (pons/midbrain) causes what?
Decerebrate/Extensor posturing?
Damage to the brainstem AT OR BELOW the level of the Red Nucleus (pons/midbrain)
What causes Cerebrate (Flexor) posturing?
Damage above the Red nucleus (cerebral hemispheres/internal capsule)
Deep brain stimulation involved what structures in parkinson’s patients? what does it do?
Subthalamic nucleus/Globus Pallidus internus; decrease firing of nuclei.
Staining for Synaptophysin means mass originated from what cell?
neurons
GFAP positive for what?
Neoplasms of glial origin (astrocytomas, ependymomas, oligodendrogliomas)
What is the Pudendal nerve susceptible to during the birth process and why?
Stretch injury; because it courses around the ischial spine and stress during birth causes this
Lacunar stroke symptoms/brain area-Pure sensory stroke
VPL/VPM
Lacunar Stroke symptoms/brain area-Ataxia-hemiplegia
posterior internal capsule/basal pons
Lacunar stroke symptoms/brain area-Dysarthria-Clumsy hand syndrome
genu of the internal capsule or basal pons
No cerebellr vermis, cystic dilation of the 4th ventricle, non-communicating hydrocephalus = ?
Dandy-walker malformation
Trendelenburg gait nerve?
Superior gluteal nerve; Patient stands on affected leg and pelvis sags towards the unaffected side
What are two drugs that can treat spasticity secondary to spinal cord/brain disease, like MS? Also what is their MOA?
Baclofen (GABA-B Agonist); Tizanidine (Alpha-2 agonist)
What structures pass through the superior orbital fissure?
CN III, IV, V1, VI, ophthalamic vein/sympathetic fibers
What structure pass through the Foramen Rotundum?
CN V2 maxillary
What structure pass through the Foramen Ovale?
CNV3 mandibular
What structures pass through the Foramen Spinosum?
Middle Meningeal Artery/vein
What structures pass through the internal acoustic meatus?
CNVII, VIII
What structures pass through the Jugular Foramen?
IX, X, XI, Jugular vein
What structures pass through the foramen magnum?
Spinal roots of CNXI, brains stem, vertebral arteries
What is it called when the axon is severed from the body of a neuron…on the neuron side?
Neuronal reaction; increased protein synthesis that facilitates axon repair; dispersed nissl substance
What is it called when the neuron body is severed from the axon…on the axon side?
Wallerian degeneration; schwann cells eating up myelin/dead axon
Elevated urine methylmalonic acid and propionic acid = ?
Methylmalonic Acidemia
Spinal Muscular Atrophy Gene/function & S/Sx
SMN1 (survival motor neuron 1); protein that helps assemble snRNPs/spliceosome;
Dalyed motor development, flaccid paralysis, hypotonia, decreased DTRs; degeneration of the anterior horn cells of the spinal cord.
What does a high blood/gas partition coefficient mean?
High solubility in the blood
What is Paraneoplastic Cerebellar Degeneration cause?
Tumor Immune response cross reacts with purkinje neuron antigens ~w [Anti-Yo, Anti-P/Q, Anti-Hu]; Small Cell Lung cancer, breast, ovarian, and uterine malignancies
Cerebellar Vermis Lesion symptoms
truncal ataxia (wide based gait), vertigo/nystagmus (flocculonodular lobe)
Diabetic CNIII Mononeuropathy symptoms
down and out pupil with ptosis, but PUPILLARY SIZE AND REACTIVITY IS NORMAL
What fibers are located where in CNIII and why is this important?
Parasympathetic fibers are located on the outside of the nerve and motor portions are on the internal part of the nerve; important for ischemia versus compression
Signs of Abusive Head Trauma (Shaken baby syndrome)
Acute on chronic SDH
Retinal hemorrhages
Posterior Rib Fractures
Injuries inconsistent with hx or developmental age
3 D’s of C. Botulinum poisoning?
Diplopia, dysphagia, dysphonia
What causes subacute sclerosing panencephalitis?
measles virus infection; years later
Symptoms of Glossopharyngeal nerve lesion
Loss of taste over posterior 1/3 of tongue
Loss of sensation of tonsils, post 1/3 of tongue, upper pharynx, middle ear
loss of gag reflex (afferent limb)
Presentation of Chiari Type 1 Malformation
adolescence/adulthood; occipital headaches, dizziness/ataxia
Presentation of Chiari II malformation
neonatal period; cerebellum and medulla through foramen magnum; non-communcating hydrocephalus 2/2 aqueductal stenosis
Medulla problems (stridor, apnea, dysphagia)
Myelomeningocele
What are causes of intraventricular hemorrhage in a newborn? (3)
prematurity (<32 weeks)
low birth weight <1500 g
occurs in first 5 days
Where is the damage in Korsakoff syndrome?
Anterior and dorsomedial thalamic nuclei.
S/Sx= anterograde amnesia
confabulation
memory loss
How does a lesion of the Ventromedial Nucleus of the Hypothalamus present?
Obesity and hyperphagia (center of satiety)
How does a lesion of the lateral nucleus of the hypothalamus present?
loss of appetite, starvation
Lesion of Anterior nucleus of the hypothalamus?
hyperthermia
Lesion of Posterior nucleus of hypothalamus?
hypothermia
What does the arcuate nucleus of hypothalamus do?
secretes:
Dopamine
Growth hormone releasing hormone
GNRH
What does the suprachiasmatic nucleus of the hypothalamus do?
circadian rhythm/pineal gland function
What does the supraoptic nucleus of the hypothalamus do?
ADH and oxytocin
Features of Frederich Ataxia?
- Degeneration of spinocerebellr tract (ataxia)
- degeneration of posterior column/DRG (proprioception/vibration)
- Skeletal abnormalities (kyphoscoliosis, pes cavus feet)
- HCM
- DM
What are 3 drugs to give for someone with Alzheimer’s Dementia?
- Cholinesterase Inhibitor (Donepezil)
- Antioxidant (Vitamin E/alpha tocopherol)
- NMDA antagonist (Memantine)-blocks overstimulation by glutamate
How do benzos affect GABA-A firing?
How do barbituates affect GABA-A firing?
Benzos: increases frequency
Barbs: increases duration
What can Physostigmine do that other acetylcholinesterase inhibitors can’t and why?
Cross the BBB
Because it is tertiary and neostigmine/edrophonium are quaternary amines
pure sensory stroke involves what part of the brain?
Thalamus;
The nuclei that relay the modalities of touch, pain, temperature, vibration, and proprioception are the ventral posterolateral (VPL) and ventral posteromedial (VPM) nuclei of the thalamus, and are supplied by the thalamogeniculate branches of the left posterior cerebral artery.
lateral pontine syndrome due to blockage of what artery?
the anterior inferior cerebellar artery (AICA); causes trigeminal and facial nerve symptoms due to decreased blood supply to the spinal trigeminal nucleus and facial nucleus. Patients also commonly present with ataxia, loss of gag reflex, and Horner’s syndrome.
The pyramidal tracts of the corticospinal tract decussate at the ____1____; therefore, any lesion that accounts for a right lateral gaze palsy, right lower facial droop, and left-sided motor weakness must occur in ____2____, above the level of the ___1___.
- caudal medulla
2. left pons
Both the sympathetic and parasympathetic nervous systems have what @ the postganglionic neurons?
nicotinic ACh receptors
Lesions to the dominant parietal lobe results in what?
Gerstmann syndrome, which is a condition characterized by agraphia, acalculia, finger agnosia, and left-right disorientation.
contralateral homonymous hemianopsia with macular sparing is the result of a stroke in what part of the brain?
posterior cerebral artery; which is loss of the ipsilateral nasal and contralateral temporal visual fields with sparing of the direct center field of vision.
uncal herniation –> palsy of what nerve?
CN III (3rd nerve palsy)
Unilateral lesions to the occipital lobe can cause? What about bilateral lesions?
Unilateral lesions: contralateral hemianopia or quadrantanopia.
Bilateral lesions: can cause cortical blindness.
superior colliculus is also involved in the coordination of eye movement; lesions to this region results in what?
vertical gaze palsy rather than horizontal gaze palsy. (progressive supranuclear palsy, or tumors of the pineal gland/region).
The lateral geniculate nucleus of the thalamus is involved in the visual pathway but not in eye movement; lesions to this structure result in what?
homonymous hemianopsia in the visual field contralateral to the side of the lesion.
The pretectal nucleus functions as a relay station for pathways from the retina to the hypothalamic nuclei, other cranial nerve nuclei, and thalamic nuclei. What are these circuits involved in?
behavioral and autonomic responses to changes in light, and not voluntary ocular movement.
Sumatriptan is a medication frequently used for abortive therapy of migraine headaches, what is it contraindicated in?
Triptans inhibit pain pathways by stimulating vasoconstriction via inhibiting the release of vasoactive peptides. Given the vasoconstrictive mechanism, triptan therapy is not recommended for patients with a history of ischemic stroke, ischemic heart disease, Prinzmetal’s angina, and uncontrolled hypertension.
What type of channel is the acetylcholine receptor present in the neuromuscular junction?
ligand-gated non-selective cation channel.
What type of channel is the acetylcholine receptor present through out the ANS? (i.e. NOT the NMJ)
GPCR
NMDA receptor is what type of channel?
voltage- and ligand-gated non-selective cation channel.