29. Central Nervous System Pathology Flashcards
(223 cards)
1
Q
What is acute purulent meningitis?
A
Purulent leptomeningeal inflammation due to bacteria.
2
Q
Which organism is responsible of acute purulent meningitis in neonates?
A
Group B streptococci, Escherichia coli.
3
Q
Which organism is responsible of acute purulent meningitis in infants and children?
A
Haemophilus influenza.
4
Q
Which organism is responsible of acute purulent meningitis in adolescents and young adults?
A
Neisseria meningitidis.
5
Q
Which organism is responsible of acute purulent meningitis in elderly?
A
Streptococcus pneumoniae and Listeria monocytogenes.
6
Q
What are two sequelae due to organization of purulent exudate and fibrosis?
A
Hydrocephalus and cranial nerve impairment (neural deafness).
7
Q
Which part of the brain does mycobaterial meningoencephalitis affect?
A
Basal surface of the brain.
8
Q
Which type of mycobateria causes meningoencephalitis? Which one in AIDS patients?
A
Usually by Mycobacterium tuberculosis or atypical mycobateria. Mycobacterium avium-intracellulare (MAI) in AIDS patients.
9
Q
What is the normal value of proteins (mg/dL) in cerebrospinal fluid?
A
15-45.
10
Q
What is the normal value of pressure (cm H2O) in cerebrospinal fluid?
A
70-180.
11
Q
What is the normal lymphocyte count in cereborspinal fluid?
A
Less than five.
12
Q
What is the normal value of glucose (ug/dL) in cerebrospinal fluid?
A
45-85 (50-70% glycemia)
13
Q
In which type of meningitis do we see normal values of glusose in CSF?
A
Aseptic (viral).
14
Q
Which types of meningitis do we see moderate 100-1000 lymphocyte count?
A
Aseptic (viral) and Granulomatous (mycobacterial/fungal).
15
Q
What are 4 clinical presentations of viral encephalitides?
A
- Perivascular cuffs.
- Microglial nodules.
- Neuron loss.
- Neuronophagia.
16
Q
What is a characteristic presentation of Herpes simplex type 1 viral encephalitis?
A
Hemorrhagic necrosis of temporal lobes.
17
Q
What micro presentation is characteristic of Rabies encephalitis?
A
Negri bodies in hippocampal and Purkinje neurons.
18
Q
What are 5 anthropod-borne viral encephalitides?
A
- St. Louis
- California
- Eastern equine
- Western Equine
- Venezuelan
19
Q
What does HIV cerebral involvement lead to?
A
AIDS-dementia complex.
20
Q
What micro presentation do we see in HIV-related encephalitides?
A
Microglial nodules and diagnostic mutlinucleated giant cells.
21
Q
What does spinal involvement of HIV lead to?
A
Vacuolar myelopathy similar to vitamin B12 deficiency-associated subacute combined degeneration.
22
Q
What virus is related to Progressive multifocal leukoencephalopathy (PML)?
A
JC virus (John Cunningham).
23
Q
What 3 micro presentations do we see in Progressive multifocal leukoencephalopathy?
A
- Demyelination.
- Lymphohistiocytic
- Astrogliosis.
24
Q
What happens to astrocytes in Progressive multifocal leukoencephalopathy? What happens to oligodendrocytes?
A
Astrocytes acquire bizarre shapes. Oligodendrocytes in active lesions contain intranuclear inclusions.
25
What are the 4 most common fungi involved in fungal meningoencephalitis?
1. Candida
2. Aspergillus
3. Cryptococcus
4. Mucor
26
What two species of fungi have a penchant for marked tropism for blood vessels?
Aspergillus and Mucor. They can cause vasculitis, rupture of blood vessels and hemorrhage.
27
What type of meningoencephalitis does Cryptococcus cause and what type of lesions?
It causes diffuse meningoencephalitis: invasion of the brain through Virchow-Robin and soap bubble lesions.
28
What does toxoplasmosis cause in the brain?
Cerebral abscess with central necrosis and chronic inflammation.
29
What do we find in MRI/CT scan of someone with toxoplasmosis?
Characteristic ring-enhancing lesions.
30
What is the cause of Creutzfeldt-Jakob disease (CJD)?
Caused by prion protein (PrP) that has turned from its normal conformation of alpha-helix PrP(C) to beta-pleated PrP(SC).
31
What gene and which chromosome is the agent that causes Creutzfeldt-Jakob disease?
The prior protein is encoded by a single-exon gene on chromosome 20.
32
What change does Creutzfeldt-Jakob disease cause in the brain?
Spongiform change by fine vacuolization of the neuropil in the gray matter (especially the cortex) due to large membrane-bound vacuoles within neuronal processes.
33
What percentage of Creutzfeldt-Jakob disease are sporadic? How many are by familial?
85% are sporadic, 15% are familial.
34
Which disease causes Subacute Spongiform Encephalopathy (SSE)?
Kuru in the Fore tribe in New Guinea due to the consumption of infected brains.
35
What is another name for Global cerebral ischemia?
Diffuse ischemic encephalopathy.
36
What are 3 vulnerable places in the brain for global cerebral ischemia?
Purkinje neurons, hippocampus CA1 (Sommer sector) and pyramidal neurons of cortex.
37
What type of strokes are the most frequent?
Infarctions (85% of all stroke cases).
38
What is the percentage of all infarctions caused by hemorrhage?
15% of all stroke cases.
39
Which type of emboli causes the majority of emboli occlusions?
By thromboemboli from cardiac chambers, less frequently due to atheroemboli.
40
At what time do we see liquefactive necrosis after cerebral infarction?
2-3 weeks after the cerebral infarction.
41
What is the most frequent predisposing condition for intracerebral (intraparenchymal) hemorrhage?
Hypertension.
42
What are the symptoms of intracerebral hemorrhage?
Severe headache, frequent nausea/vomiting, steady progression of symptoms over 15-20 minutes and coma.
43
Which is the most frequent artery involved in epidural hemorrhage?
Middle meningeal artery.
44
Which type of brain herniation does epidural hemorrhage lead to if not promptly evacuated?
Usually subfalcine.
45
What is the "talk-and-die syndrome" and in which pathology does it present?
It is the lucid interval before loss of consciousness seen in epidural hemorrhage.
46
What is the cause of epidural hemorrhage?
Virtually traumatic, associated with skull fractures, due to tear of dural arteries, most frequently middle meningeal artery.
47
What is the cause of subdural hemorrhage?
Usually (in contrast to epidural which is virtually) traumatic, caused by the rupture of bridging veins (from cerebral convexities to sagittal sinus).
48
What are the symptoms of subdural hemorrhage?
Headache, drowsiness, focal neurologic deficits, sometimes dementia. Recurs frequently.
49
What is the most frequent cause of subarachnoid hemorrhage?
Ruptured berry aneurysms.
50
What are the symptoms of subarachnoid hemorrhage?
Sudden ("thunderclap") headache, nuchal rigidity, and neurological deficits on one side, and stupor.
51
What is a berry aneurysm?
Thin-walled sacular outpouchings, consisting of intima and adventitia only.
52
What is the most frequent site of berry aneurysm?
Anterior circle of Willis at branching points.
53
What are 3 pathologies associated with berry aneurysms?
1. Marfan syndrome.
2. Ehlers-Danlos type 4.
3. Adult polycystic kidney disease.
54
What is the prognosis after a berry aneurysm rupture?
1/3 die, 1/3 recover, 1/3 rebleed.
55
What is a concussion?
Change in the momentum of the head (impact against a rigid surface).
56
What are the clinical manifestations of a concussion?
Loss of consciouness and reflexes, temporary respiratory arrest, and amnesia for the event.
57
What is a contusion?
Impact of parts of the brain against the inner calvarial surfaces. Causes bruising to the brain resulting from tissue and vessel disruption.
58
Describe the site of injury of a contusion.
Crests of orbital gyri in frontal and temporal poles.
59
What are "Coup" and "contrecoup" and when do we see them?
Coup: site of injury
Contrecoup: site of diametrically opposite.
They both develop when the head is mobile at the time of impact in contusions.
60
What happens in an acute contusion?
Hemorrhage of brain tissue in wedge-shaped area.
61
What happens in subacute contusions?
Necrosis and liquefaction of brain.
62
What happens in remote contusions?
Depressed area of cortex with yellow discoloration ("plaque jaune")
63
What is diffuse axonal injury?
Injury to the white matter due to acceleration/deceleration. It causes damage to axons at the nodes of Ranvier with impairment of axoplasmic flow.
64
What five sites of the brain does diffuse axonal injury has a predilection for?
1. Corpus callosum.
2. Periventricular white matter.
3. Hippocampus
4. Cerebral peduncles.
5. Cerebellar peduncles.
65
What micro presentations does diffuse axonal injury cause?
Axonal swellings appreciable in the white matter.
66
What is the clinical presentation of diffuse axonal injury?
Coma after trauma without evidence of direct parenchymal injuries.
67
What does the prognosis of diffuse axonal injury depend on?
Related to the duration of coma.
68
What do lesions to the thoracic segments or below cause?
Paraplegia.
69
What do lesions to cervical segments cause?
Tetraplegia.
70
What do lesions above C4 cause and why?
Respiratory arrest due to paralysis of diaphragm.
71
What is another name for Subfalcine herniation?
Cingulate gyrus herniation.
72
What happens in a Subfalcine herniation?
Cingulate gyrus is displaced underneath the falx to the opposite side. Causes compression of anterior cerebral artery.
73
What is another name for Transtentorial herniation?
Uncal herniation.
74
What is acute aseptic meningitis and what micro presentation do we see?
Leptomeningeal inflammation due to viruses (enterovirus most frequent). Lymphocytic infiltration of leptomeninges and superficial cortex.
75
What happens in a transtentorial hernia?
Uncus of the temporal lobe is displaced over the free edge of the tentorium. Compression of the third nerve; pupillary dilation on the same side, infacrt in dependnt territory.
76
What happens in the advanced stages of transtentorial herniation?
Durret hemorrhage within the central pons and midbrain.
77
What is Cerebellar tonsillar?
Displacement of cerebellar tonsils through the foramen magnum.
78
What happens in the compression of medulla?
Cardiorespiratory arrest.
79
What is anencephaly?
Absence of cranial vault; incompatible with life -babies soon die after birth.
80
What is spina bifida?
Bony defect of the vertebral arch.
81
What is meningocele?
Bony defect with outpouching of the meninges.
82
What is meningomyelocele?
Defective formation of the bony arch with cystic outpouching of meninges, spinal cord, and spinal roots.
83
What is myelocele?
Defective bony arch with complete exposure of spinal cord.
84
Which neural defect does not lead to increas in alfa-fetoprotein during pregnancy?
Spina bifida occulta.
85
What is Anorld-Chiari malformation?
It is faulty craniospinal junction, resutling in small posterior fossa with: (4)
1. Downward displacement of cerebellar vermis and medulla.
2. Compression of the fourth ventricle.
3. Obstruction hydrocephalus.
4. Frequent lumbar meningomyelocele.
86
What other pathology is Arnold-Chiari malfomation is associated with?
Syringomyelia.
87
Which type of Arnold-Chiari malformation is the most common?
Type 1
88
Which type of Arnold-Chiari malformation is the most symptomatic?
Type 2.
89
Which type of Arnold-Chiari malformation is the one with downward displacement of cerebellar tonsils?
Type 1.
90
What is Syringomyelia?
Ependymal-lined, CSF-filled channel parallel to and connected with central canal . (Hydromyelia: central canal is simply dilated). Syrinx enlarges progressively and destroys the spinal parenchyma.
91
Which type of Arnold-Chiari malformation is 90% associated with syringomyelia?
Type 2.
92
What are other causes of syringomyelia other than Arnold-Chiari?
Post-traumatic or associated with intraspinal tumors.
93
What are the symptoms of Syringomyelia?
Paralysis and loss of sensory functions.
94
What is the most common cause of cerebral palsy?
Perinatal brain injury.
95
What happens in a transtentorial hernia?
Uncus of the temporal lobe is displaced over the free edge of the tentorium. Compression of the third nerve; pupillary dilation on the same side, infacrt in dependnt territory.
96
What happens in the advanced stages of transtentorial herniation?
Durret hemorrhage withing the central pons and midbrain.
97
What is Cerebellar tonsillar?
Displacement of cerebellar tonsils through the foramen magnum.
98
What happens in the compression of medulla?
Cardiorespiratory arrest.
99
What is periventricular leukomalacia?
Infarcts in watershed areas (periventricular white matter in the fetus) seen in perinatal brain injury.
100
What is Multicystic encephalopathy?
Multiple brain infarcts occuring early in preganancy.
101
What is multiple sclerosis?
Chronic relapsing-remitting disorder of probable autoimmune origin characterized by recurrent episodes of demyelination in the brain (including optic nerves) and spinal cord, which results in progressive neurological deficits.
102
Which gender is more probable of developing multiple sclerosis?
Women.
103
Which gene is strongly associated with multiple sclerosis?
HLA-DR2
104
What five infectious agents are suspected of causing multiple sclerosis?
1. Mumps
2. Rubella
3. Herpes simplex
4. Measles
5. JC virus
105
What is the gross presentation of acute lesion of multiple sclerosis?
Well circumscribed plaques, with loss of myelin, frequently periventricular, with same color as gray matter.
106
What is the micro presentation of an acute lesion of multiple sclerosis?
Chronic (yes, chronic) inflammation , with phagocytosis of myelin by macrophages; axons are initially preserved.
107
What is the micro presentation of chronic lesions of multiple sclerosis?
No inflammation, with axons showing remyelination.
108
Why is remyelination defective in multiple sclerosis?
Because myelin sheaths are thinner with shorter internodes.
109
What is the pathophysiology of an acute attack of multiple sclerosis?
Nerve conduction is entirely blocked, acute neurological deficits.
110
What is the pathophysiology of a chronic plaque in multiple sclerosis?
Slower nerve conduction, allowing for partial recovery.
111
What type of course does 85% of cases have?
Relapsing-remitting course. Recovery from each episode of demyelination occurs in weeks or months.
112
What organ is affected with diplopia and vertigo in multiple sclerosis?
Brainstem.
113
What organ is compromised in the presence of loss of sensation or weakness in one leg?
Spinal cord.
114
What organ is compromised in the involvement of hemiparesis or loss of sensation of half of the body?
Cerebral white matter.
115
What is the treatment for acute attacks in mutliple sclerosis?
High-dose steroids facilitates recovery.
116
What are the long term treatments for multiple sclerosis?
Interferon-B and Copolymer 1 (Copaxone).
117
What are three immune factors involved in multiple sclerosis?
1. Oligocolonal CD4 lymphocytic infiltration.
2. Experimental allergic encephalitis (EAE) obtained by injection of myelin basic protein (MBP).
3. T(H1) cytokines (IF-gama and TNF) facilitate; T(H2) cytokines (IL-4 and IL-10) retard EAE.
118
What is Central pontine myelinosis (CPM)? And what is the pathophysiology of it?
Focal demyelination of central area of "basis pontis". Probably derives from rapid correction of hyponatremia.
119
What type of patients is at risk for central pontine myelinosis?
Severely malnourished alcoholics with liver disease.
120
What is Parkinson disease and syndrome cause and why?
Loss of dopaminergic neurons in the substantia nigra, causes tremor, rigidity and akinesia.
121
What is the difference between Parkinson disease and Parkinson syndrome?
Disease (PD) is the idopathic form. Syndrome (PS) is secondary to known injuries to the substantia nigra (SN) (e.g., infections, vascular conditions, toxic insults).
122
What chemical can cause Parkinson syndrome?
Exposure to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes death of dopaminergic neurons in SN. MPTP is a byproduct of illicit synthesis of meperidine analogue.
123
What is the gross presentation of Parkinson?
Pallor of substancia nigra (SN).
124
What is the micro presentation of Parkinson?
Loss of pigemented (dopaminergic) neurons in Substancia nigra. Presence of Lewy bodies.
125
What are Lewy bodies?
Lewy bodies are intracytoplasmic round eosinophilic inclusions that contain alpha-synuclein. They can be seen in the substancia nigra in Parkinson and in other places in other pathologies.
126
What is the pathophysiology of Parkinson?
Loss of extrapyramidal nigra-striatal pathway. Causes inhibition of movement of proximal muscles and disruption of fine regulation of distal muscles. The pathophysiology of Parkinson disease associated dementia is not clear.
127
What are 5 clinical presentations of Parkinson?
1. Slowing of all voluntary movements.
2. Tremor at rest that disappears during movement.
3. Expressionless face.
4. Rigidity of limbs and trunk and inability to initiate voluntary movement.
5. Increased incidence of dementia and depression.
128
What is the treatment for Parkinson?
Levadopa.
129
What is Hunting Disease (HD)?
Autosomal dominant disease characterized pathologically by degeneration of GABA-nergic neuros of caudate nucleus and clinically by chorea and dementia.
130
Which gene and what chromosome is responsible for Huntington Disease?
HD gene is located in chromosome 4 coding for a protein called "huntington".
131
What is a rare characteristic of Huntington in terms of hereditary matters?
HD shows features of anticipation and genomic imprinting.
132
What is the cause of Huntington Disease?
Mutations are due to expansion of an unstable trinucleotide repeat of "CAG".
133
What is the gross presentation of Huntington Disease?
Atrophy of the caudate nucleus with secondary ventricular dilation.
134
What is the micro presentation of Huntington Disease?
Loss of small neurons in the caudate nucleus.
135
What is the pathophysiology of Huntington Disease?
Loss of caudate nucleus GABA-nergic neurosn removes inhibitory influences on extrapyramidal circuits, thus leading to chorea.
136
What are two clinical presentations of Huntington Disease?
1. Chorea: sudden, unexpected and purposeless contractions of proximal muscles.
2. Changes in Personality: Marked tendency for suicide and dementia.
137
What is the cause of 60% of a dementias?
Alzheimer disease (AD).
138
What are 3 mutations know to cause Alzheimer's Disease?
1. Amyloid precursor protein (APP).
2. Presenilin-1 gene
3. Apolipoprotein E gene.
139
In which chromosome is the Amyloid precursor protein found? And in which pathology is the subject virtually guaranteed to develop Alzheimer disease (AD)?
Amyloid precursor protein gene is found on chromosome 21. Virtually all Down syndrome subjects are destined to develop AD in their forties because they have triple copies of the APP gene.
140
On which chromosome is Presenilin-1 gene found? What does it cause?
Chromosome 14. Causes Alzheimer Disease.
141
On which chromosome is Presenilin-2 gene found? What does it cause?
Chromosome 2. Causes Alzheimer Disease.
142
Which gene mutation is the cause of the majority of hereditary Alzheimer Disease?
Presenilin-1 gene.
143
Which gene mutation is associated with late onset of Alzheimer Disease?
Apolipoprotein 4 e4 gene.
144
What are the two abnormal proteins that produced in Alzheimer Disease?
1. A-Beta amyloid: 42-residue peptide from a normal transmembrane protein, the amyloid precursor protein (APP).
2. Abnormal tau (a microtubules-associated protein).
145
What are senile plaques and in which pathology are they seen?
Core of A-beta amyloid surrounded by dystrophic neuritic/dendritic processes and associated with microglia and astrocytes. They are seen in Alzheimer Disease.
146
What are neutrofibrillary tangles (NFT) and in which pathology are they seen?
They are intraneuronal aggregates of insoluble cytoskeletal elements, mainly composed of abnormally phosphorylated tau forming paired helical filaments. They are seen in Alzheimer Disease.
147
What is Cerebral amyloid angiopathy (CAA) and in which pathology are they seen?
It is accumulation of A-beta amyloid within the media of small and medium-size intracortical and leptomeningeal arteries. CAA may occur by itself and cause intracerebral hemorrhage.
148
What 2 abnormal things develop in the hippocampus in Alzheimer Disease?
Granulovacuolar degeneration (GVD) and Hirano bodies (HBs). They are less significant diagnostically.
149
What 4 distinct sites of the brain develop lesions during Alzheimer Disease?
1. Neocortex.
2. Hippocampus.
3. Several subcortical nuclei, including forebrain cholinergic nuclei (i.e., basal nucleus of Meynert).
4. Temporal lobes.
150
What are gross presentations in Alzheimer Disease?
Brains are smaller (atrophic), with thinner gyri and wider sulci. Hippocampi and temporal lobes are markedly atrophic.
151
What are 4 clinical presentations of Alzheimer Disease?
1. Progressive memory impairment, especially related to recent events.
2. Alterations in mood and behavior.
3. Progressive disorientation.
4. Aphasia (loss of language skills) and apraxia (loss of learned motor skills).
152
What is the prognosis of Alzheimer Disease patients?
Insidious onset beginning usually in the seventh or eighth decade. Within 5-10 years, patients become mute and bedridden.
153
What pharmacologic agent gives mild improvement for Alzheimer Disease patients?
Acetylcholinesterase (e.g., tacrine).
154
What is the cause of Dementia with Lewy bodies?
Obscure, no known risk factors.
155
What is the pathophysiology of Dementia with Lewy bodies?
The hallmark is Lewy body that is also seen in Parkinson Disease. There is neuron loss accompanied by Lewy body formation.
156
What are two distinct sites affected by dementia with Lewy bodies?
1. Neocortex, especially the limbic systems and cingulate gyrus.
2. Subcortical nuclei: basal nucleus of Meynert, amygdala, and substantia nigra.
Involvement of both sites is what causes cognitive deterioration and parkinsonism.
157
What is the 3 clinical manifestation of Dementia with Lewy bodies?
1. Memory loss
2. Parkinsonism
3. Visual hallucinations
158
What is amyotrophic lateral sclerosis?
Degeneration and loss of upper and/or lower motor neurons that usually manifests in middle age.
159
What are two clinical manifestations of the loss of upper motor neurons in amyotrophic lateral sclerosis?
1. Hyperreflexia
| 2. Spasticity
160
What are 3 clinical manifestations of loss of lower motor neurons in Amyotrophic lateral sclerosis?
1. Weakness
2. Atrophy
3. Fasciculations
161
What method is used to diagnose amyotrophic lateral sclerosis?
Biopsy of muscle.
162
What two anatomical sites does amyotrophic lateral sclerosis affect?
1. Primary lateral sclerosis of the corticospinal tract.
2. Progressive spinal muscular atrophy of the ventral horn.
In some cases, involvement of cranial nerve nuclei.
163
What is the etiopathogenesis of a small number of cases of amyotrophic lateral sclerosis?
Due to mutation of the gene encoding zinc-copper superoxide dismutase on chromosome 21.
164
What is the cause of Friedreich ataxia?
Due to expansion of an unstable triplet nucleotide repeat in frataxin gene. It causes degeneration of a group of neurons.
165
What are the 6 group of neurons that degenerate in Friedreich ataxia?
1. Dorsal root ganglia.
2. Clarke's column (origin of spinocerebellar tract)
3. Neurons of posterior column of spinal cord.
4. Cranial nerve nuclei of VII, X and XII.
5. Dentate nucleus and Purkinje cells of cerebellum.
6. Betz neurons of primary motor cortex.
166
What are 6 clinical manifestations of Friedreich ataxia?
1. Gait ataxia
2. Dysarthria
3. Hand clumsiness
4. Loss of sense of position.
5. Impaired vibratory sensation.
6. Loss of tendon reflex.
167
What percentage of the tumors of the brain and spinal cord are metastatic?
Half of them are metastatis.
168
What are the 2 most frequent primary CNS tumors?
1. Meningiomas
| 2. Glioblastoma multiforme.
169
What are 5 clinical manifestations of CNS tumors?
1. Headache, often worse at night or early morning.
2. Seizures, with tumors involving cerebral cortex.
3. Mental changes (e.g., deficits in memory, concentration, reasoning, etc.)
4. Focal neurological symptoms, related to involvement of specific brain regions.
5. Symptoms related to increased intracranial pressure.
170
What are 3 ways that can raise intracranial pressure?
1. Presence of space-occupying mass within the cranial cavity.
2. Blockage of CSF flow.
3. Edema around the tumor (peritumoral edema).
171
What is one important trait of malignant CNS tumors?
They do no metastasize outside the cranial cavity.
172
What are 3 properties of primary CNS tumors?
1. Poorly circumscribed.
2. Usually single.
3. Location varies according to specific type.
173
What are 3 properties of Metastatic CNS tumors?
1. Well circumscribed.
2. Often multiple
3. Usually located at the junction between gray and white matter.
174
What are 3 general things for Astrocytomas?
1. Fibrillary background.
2. Immunoreactivity for glial fibrillary acidic protein (GFAP).
3. Diffuse (ill-decarcated) pattern of growth.
175
What are the 2 most common grading scales used for fibrillary astrocytomas?
Daumas-Duport and WHO.
176
What are grades 1-2 astrocytomas?
Well differentiated astrocytomas.
177
What is a grade 3 astrocytoma?
Anaplastic astrocytomas.
178
What is a grade 4 astrocytoma?
Glioblastoma multiforme (GBM).
179
Which type of astrocytomas is the most common?
Glioblastoma multiforme.
180
What is a characteristic micro presentation of glioblastoma multiforme (GBM)?
Areas of necrosis surrounded by rows of neoplastic cells (pseudopalisading necrosis).
181
What is the most common location for astrocytomas?
White matter, commonly in the centrum semiovale.
182
Which age group presents well differentiated astrocytomas that grow slowly?
Younger patients.
183
Which age group has anaplastic astrocytomas and glioblastoma mulitorme that is aggressive?
Older patients.
184
Why do they call glioblastoma multiforme, "Butterfly glioma"?
It has a tendency to cross the midline by involving the corpus callosum.
185
What is a pilocytic astrocytoma?
Benign astrocytic tumor of children and young adults.
186
Where are 2 usual location of a pilocystic astrocytoma?
1. Posterior fossa (cerebellum)
| 2. Diencephalon
187
What is a usual macro presentation of pilocytic glioblastoma?
Often presents as a cystic lesion with a mural nodule.
188
What is the micro presentation of a pilocytic glioblastoma?
Spindly neoplastic astrocytes with long bipolar processes: tumors rich in Rosenthal fibers, thick corkscrew-like eosinophilic structures, which derive from hypertrophic precesses of astrocytes.
189
What is a location of pilocytic glioblastoma that has a favorable prognosis?
Tumors in posterior fossa.
190
What is oligodendroglioma?
A glioma of oligodendroglial origin. Often manifests with seizures.
191
What is the location of oligodendroglioma?
White matter of cerebral hemisphere adjacent to neocortex.
192
What are 3 characteristic micro presentations?
1. Neoplastic cells are similar to oligodendroglia.
2. Pronounced perinuclear halo: "fried-egg" apperance.
3. Prominent capillary network in chickenwire pattern.
193
What is the prognosis for cases of oligodendroglioma?
Not good since they are slow-growing tumors that allow long survival (5-10 years). Recur after surgery and degenerate into high-grade gliomas over time.
194
What is an ependymoma?
Glioma of ependymal origin.
195
What is the location of ependymoma in children?
Fourth ventricle.
196
What is the location of ependymoma in adults?
Lateral ventricle or spinal canal.
197
What is the macro presentation of ependymoma?
Circumscribed tumors with papillary architecture.
198
What is the micro presentation of ependymoma?
Neoplastic cells resemble ependymal cells. Characteristic features:
1. Ependymal rosettes: cells organized around a lumen.
2. Perivascular pseudorosettes: cells arranged around small vessels.
199
What is the prognosis of ependymoma?
Tend to recur after surgery and acquire more aggressive behavior.
200
What are meningioma?
Originates from meningothelial cells of the arachnoid.
201
What is the demographics for meningioma?
Tumors of adulthood (women>men), rare in children.
202
What is the gross presentation of Meningioma?
Attached to the dura, pushes underlying brain without invasion.
203
What are 3 micro presentations of meningioma?
1. Spindle-shaped cells with indistinct borders (syncytial).
2. Cells arranged in whorls or fascicles.
3. Psammmoma bodies are frecuent.
204
What is the location for meningiomas?
May develop at any site but the most frequent are dural convexities. Tumors in some locations may not be amenable to complete resection.
205
What is the prognosis for meningioma?
Generally good.
206
What are Primitive neuroectodermal tumors (PNET)?
Highly undifferentiated that originate from a primordial neuroglial precursor.
207
What are the 2 most frequent Primitive neuroectodermal tumors?
Medulloblastoma and ritinoblastoma.
208
What are 3 characteristics that all primitive neuroectodermal tumors share?
1. Develop in children.
2. Highly aggressive but respond to radiation therapy.
3. Histo: blue, small, round cell tumors with pseudoresettes.
209
Where do the medulloblastomas arise from?
From the cerebellar vermis (midline location).
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What are Schwannomas?
Originates from Schwann cells of cranial or spinal nerves.
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What is the most frequent location of Schwannomas?
Eight cranial nerve, cerebellopontine angle (CPA).
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What are the 2 characteristic clinical presentation of Schwannoma?
Loss of hearing and tinnitus.
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What are 2 micro presentations of Schwannoma?
1. Spindly cells arranged in hypercellular Antoni A areas, alternating with hypocellular Antoni B areas.
2. Verocay bodies: parallel rows of neoplastic Schwann cells.
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What protein are Schwannoma neoplastic cells immunoreactive to?
Protein S-100.
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Bilateral acoustic schwannomas are pathognomonic for which disease?
Neurofibromatosis type 2.
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What is the prognosis for Schwannoma?
Good prognosis after surgical resection.
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What is a Craniopharyngioma?
Tumor that arises from rests of odontogenic epithelium within the suprasellar/diencephalic region.
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What is a macro presentation of Craniopharyngioma?
Contains deposits of calcium evident on X-rays.
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Which demographic does craniopharyngioma affect?
Children or young adults.
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What is the micro presentation of craniopharyngioma?
Resembles adamantinoma, the most common tumor of the tooth.
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What is the prognosis for craniopharyngioma?
Benign but tends to recur after resection.
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What is the most common cause of subdural effusion?
Meningitis caused by Haemophilus Influenzae.
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What is meralgia paresthetica and what is the most common presentation of it?
Tingling, numbness and burning pain in the outer thigh. It is usually unilateral and may intensify after walking or standing.
