Chapter 17 CNS Flashcards
1
Q
Invagination of the neural plate early in gestation forms what?
A
The neural tube
2
Q
What do the following structures eventually form?Wall of the neural tubeHollow lumenneural crest
A
Wall of the neural tube forms CNS tissueHollow lumen forms ventricles and spinal cord canalNeural crest forms the PNS
3
Q
What nutritional deficiency is associated with NTD?
A
Folate PRIOR to conception
4
Q
What marker in maternal blood and amniotic fluid is used to test for neural tube defects?
A
elevated AFP levels in amniotic fluid and maternal blood
5
Q
What maternal complication does does anencephaly lead to?
A
polyhydramnios since fetal swallowing of amniotic fluid is impaired
6
Q
How does spina bifida and spina bifida occulta present?
A
Spina bifida presents as with cystic protrusion of the underlying tissue through the vertebral defectspina bifida occulta presents as a dimple or patch of hair overlying the vertebral defect
7
Q
What is the difference between a miningocele and a meningomyelocele?
A
Meningocele - protrusion of meningesMeningomyelocele - protrusion of meninges and spinal cord
8
Q
What is the cerebral aqueduct?
A
channel that drains CSF from the 3rd to the 4th ventricle
9
Q
What does cerebral aqueduct stenosis lead to?
A
hydrocephalus
10
Q
How does CSF move from lateral to third ventricle?
A
interventricular Foramen of monro
11
Q
How does CSF flow from the 4th ventricle into the subarachnoid space?
A
Via the foramina magendie and luschka
12
Q
How does congenital cerebral aqueduct stenosis present in newborns?
A
Presents with enlarging head circumference due to dilation of the ventricles (Cranial suture lines are not fused)
13
Q
Where is CSF produced?
A
Choriod plexus
14
Q
What is the Dandy-Walker Malformation, and how does it present?
A
Congenital failure of the cerebellar vermis to develop. Presents as a massively dilated 4th ventricle (posterior fossa) with an absent cerebellum; often accompanied by hydrocephalus
15
Q
What is the Arnold-Chiari Malformation Type I and II?
A
Type I is usually asymptomatic Type II is congenital downward displacement of the cerebellar vermis and tonsils though the foramen magnum
16
Q
What does an Arnold-Chiari type II malformation lead to?
A
Commonly results in hydrocephalus due to obstruction of CSF flow. It is often associated with meningomyelocele and syringomyelia
17
Q
What is syringomyelia?
A
Cystic degeneration of the spinal cord
18
Q
How does syringomyelia commonly arise?
A
With trauma or in association with a type 1 arnold-chiari malformation
19
Q
At what spinal level does syringomyelia generally occur?
A
C8-T1
20
Q
How does syringomyelia present?
A
Sensory loss of pain and temp with sparing of fine touch and position sense in the upper extremities (“cape like” distribution)
21
Q
What spinal cord structure is involved in syringomyelia?
A
anterior white commisure of the spinothalamic tract with sparing of the dorsal column
22
Q
What addition symptoms can occur in syringomyelia is the syrinx expands into other spinal structures?
A
Muscle atrophy and weakness with decreased muscle tone and impaired reflexes- due to damage to lower motor neurons of the anterior hornHorner syndrom with ptosis, miosis, and anhydrosis due to disruption of the lateral horn of the hypothalamospinal tract
23
Q
Where does polio initially infect? how does it spread to CNS?
A
Initially infects small bowel and oropharynx giving you constitutional symptoms then eventually spreads to CNS by the blood and infects anterior horn
24
Q
What spinal cord structure is damages in poliomyelitis?
A
damage to the anterior motor horn due to poliovirus infection
25
How does poliomyelitis present?
with lower motor neuron signs- flaccid paralysis with muscle atrophy, fasciculations. weakness with decreased muscle tone, impaired reflexes, and negative babinski sign (downgoing toes)
26
What is Werding-Hoffman Disease and how does it present?
| What is the inheritance pattern?
Inherited degeneration of the anterior motor horn: autosomal recessive. Presents as a "floppy baby"; death occurs within a few years after birth
27
What types of neurons are affected in Amyotrophic lateral sclerosis?
Upper and lower motor neurons of the corticospinal tract
28
What does anterior horn degeneration in ALS lead to?
leads to lower motor neuron signs - flaccid paralysis with muscle atrophy, fasciculations, weakness with decreased muscle tone, impaired reflexes, and negative babinski sign.
29
What does lateral corticospinal tract degeneration lead to in ALS?
Leads to upper motor neuron signs - spastic paralysis with hyperreflexia, increased muscle tone, and positive babinski sign
30
What is an early sign in ALS?
atrophy and weakness of hands
31
What distinguishes ALS from syringomyelia?
Lack of sensory impairment
32
Are most cases of ALS sporadic or inherited?
sporadic occurring in middle aged adults
33
What mutation is implicated in familial ALS?
Zinc-copper superoxide dismutase (SOD1) leads to free radical injury (O2 --> H2O2)
34
What structures are involved in Friedreich Ataxia?
Degeneration of the Cerebellum and spinal cord
35
What does degeneration of the cerebellum lead to in friedreichs astaxia?
ataxia
36
What does degeneration of multiple spinal cord tracts lead to in friedreichs ataxia?
loss of vibratory sense and proprioception, muscle weakness in the lower extremities, and loss of deep tendon reflexes
37
How is Friedreichs ataxia inherited and what is the defect?
AR, due to expansion of an unstable trinucleotide repeat GAA in the frataxin gene
38
What is frataxin and what does loss result in?
Frataxin is essential for mitochondrial iron regulation; loss results in iron buildup with free radical damage
39
When does Friedreichs ataxia present?
in early childhood; patients are wheelchair bound within a few years
40
What complication is friedreichs ataxia associated with?
hypertrophic cardiomyopathy
41
What are the leptomeninges?
The pia and the arachnoid?
42
What layers are inflammed in meningitis?
the leptomeninges
43
What are the 3 most common infectious agents leading to meningitis in neonates?
Group B strepE coliListeria Monocytogenes
44
What is the most common viral cause of meningitis in children?
Cocksackievirus (fecal-oral transmission)
45
What is the most common bacterial cause of meningitis in children and teens?
N Meningitidis
46
What is the most common bacterial cause of meningitis in adults and elderly?
Steptococcus Pneumoniae
47
What is the most common bacterial cause of meningitis in nonvaccinated infants?
H. Influenza
48
What is the most common cause of meningitis in immunocompromised patients?
Fungi
49
What is the classic presenting triad of meningitis and what are some other associated symptoms?
Classic triad - headache, nuchal rigidity, and fever Other associated - photophobia, vomiting and altered mental status
50
How is diagnosis of meningitis confirmed?
Lumbar puncture
51
What spinal level is an LP performed at and what space is samples?
between L4 and L5 (level of iliac crest) and samples subarachnoid space
52
Where does the spinal cord end?
L2
53
What are the CSF findings in bacterial meningitis?
neutrophils and decreased glucose (bacteria consume it)gram stain and culture often identify the causative organism
54
What are the CSF findings in viral meningitis?
lymphocytes with NORMAL CSF glucose
55
What are the CSF findings in fungal meningitis?
lymphocytes with decreased CSF glucose
56
What is a normal level of CSF glucose?
~2/3 of serum glucose
57
What percentage of cerebrovascular disease is due to ischemia and what percent is due to hemorrhage?
ischemia 85%Hemorrhage 15%
58
How fast to neurons undergo necrosis due to ischemia?
3-5 min
59
Which cause of meningitis is usually associated with complication and why?
bacterial meningitis due immune reaction creating massive amounts of exudate and pus
60
What complications seen with bacterial meningitis?
Death - herniation secondary to cerebral edema hydrocephalus, hearing loss, and seizures are all related to fibrosis caused by the healing process
61
Name four causes of global ischemia to the brain
1 Low perfusion (atherosclerosis)
2 Acute decrease in blood flow (Cardiogenic shock)
3 Chronic Hypoxia (anemia)
4 Repeated episodes of hypoglycemia (insulinoma)
62
What do the clinical features of global ischemia depend on?
duration and magnitude of the insult
63
What does mild global ischemia result in and what is the classic example?
transient confusion with prompt recovery. Classic example is insulinoma
64
What does severe global ischemia lead to?
results in diffuse necrosis which most dont survive. those who do survive are left in a vegetative state
65
What does moderate global ischemia lead to?
infarcts in watershed areas between the anterior and middle cerebral arteries and damage to highly vulnerable regions
66
Name 3 highly vulnerable locations for moderate global ischemia
1 pyramidal neurons of the cerebral cortex (layers 3,5,6) leads to laminar necrosis - known as cortical laminar necrosis
2 Pyramidal neurons of the hippocampus (temporal lobe)- important in long term memory
3 Purkinje layer of the cerebellum - integrates sensory perception with motor control
67
What is an ischemic stroke and how does it differ from a transient ischemic event (TIA)?
regional ischemia to the brain that results in focal neurologic deficits lasting > 24 hours. If symptoms last < 24 hours the event is termed a TIA
68
What are the 3 subtypes of ischemic strokes?
thrombotic, embolic, and lacunar
69
What are thrombotic strokes due to?
rupture of an atherosclerotic plaque
70
Where does atherosclerosis tend to develop?
at branch points ( eg bifurcation of internal carotid and middle cerebral artery in the circle of willis)
71
What type of infarct does a thrombotic stroke cause?
Pale. The body with try and lyse this but since the plaque is ruptured the thrombosis with continue to reform
72
What is the most common source of emboli in an embolic stroke?
left side of the heart (eg atrial fibrillation)
73
What artery is usually involved in a hemorrhagic stroke?
middle cerebral
74
What type of infarct does an embolic stroke result in?
hemorrhagic infarct at the periphery of the cortex. Thrombus eventually gets lysed and blood goes back in
75
What do lacunar strokes occur secondarily to?
hyaline arteriosclerosis; a complication of HTN (benign HTN or diabetes)
76
What vessels are usually involved in lacunar strokes? and what is the result?
SMALL vessels, most commonly the lenticulostriate vessels (Branches of the MCA) resulting in small cystic areas of infarction
77
What two major areas of the brain are involved in lacunar strokes and what are the consequences?
Internal capsule involvement leads to a pure motor strokeThalamus involvment leads to pure sensory stroke
78
What type of necrosis do ischemic strokes lead to?
liquefactive
79
What is an early microscopic finding in ischemic strokes?
Eosinophillic change in the cytoplasm of neurons (RED NEURONS) occurs after about 12 hours
80
What cells cause necrosis in ischemic strokes?
Neutrophils then microglial cells
81
What is gliosis and when does it occur after an infarct?
Gliosis is reactive astrocytes that will line the cystic space with gliotic connective tissue similar to granulation tissue
82
How long does it take to form a fluid filled cyst after an ischemic stroke?
about 1 month
83
What is an intracerebral hemorrhage?
Bleeding into the brain parenchyma
84
What are the classic cause of intracerebral hemorrhage?
rupture of Charcot-Brouchard microaneurysms of the lenticulostriate vessels
85
What is intracerebral hemorrhage a complication of and what structures are most commonly affected?
Complication of hypertension; treatment of hypertension reduces the incidence by halfBasal ganglia is the most common site
86
How do intracerebral hemorrhage present?
severe headache, nausea, vomiting, and eventual coma
87
How does a subarachnoid hemorrhage present?
presents as a sudden headache ("worst of my life") with nuchal rigidity
88
What does lumbar puncture show in subarachnoid hemorrhage?
xanthochromia (yellow hue due to bilirubin breakdown)
89
What is the most frequent cause of subarachnoid hemorrhage and what are two other causes?
Most frequently (85%) due to rupture of a berry aneurysm; other causes include AV malformations and an anticoagulated state.
90
Describe a berry aneurysm and the most frequent location
Berry aneurysms are thin walled saccular outpouching that lack a media layer, increasing the risk for ruptureMost frequently located in the anterior circle of willis at branch points of the anterior communicating artery
91
What conditions are associated with berry aneurysm and subarachnoid hemorrhages?
Marfan syndrome and autosomal dominant polycystic kidney disease
92
Where does blood collect in an epidural hematoma?
Collection of blood between the dura and the skull
93
What is the classic cause of an epidural hematoma?
fracture of the temporal bone with rupture of the middle meningeal artery; bleeding separates the dura from the skull.
94
What is seen on CT with an epidural hematoma?
a lens shaped lesion
95
Why is an epidural hematoma called the talk and die syndrome?
Because a lucid period may precede neurological deficits
96
What is a lethal complication from epidural hematoma?
herniation
97
Where does blood collect in a subdural hematoma?
blood underneath the dura; blood covers the surface of the brain
98
What are subdural hematomas due to?
tearing of bridging veins that lie between the dura and arachnoid; usually arises with trauma
99
What is seen on CT with a subdural hematoma?
A crescent shaped lesion. also is the only type where you will see a bleed on the bottom of the brain
100
How does a subdural hematoma present?
presents with progressive neurological signs as blood builds up.
101
Which population has an increased rate of subdural hematomas and why?
increased rate of occurrence in the elderly due to age related cerebral atrophy which stretches the veins
102
What is the lethal complication of subdural hematomas?
herniation
103
What does tonsillar herniation involve? what does it cause?
the displacement of the cerebellar tonsils into the foramen magnum which causes compression of the brain stem and leads to cardiopulmonary arrest
104
What does subfalcine herniation involve? what does it cause?
displacement of the cingulate gyrus under the falx cerebri which causes compression of the anterior cerebral artery which leads to infarction.
105
What does uncal herniation involve? what does it cause?
displacement of the temporal lobe uncus under the tentorium cerebelli which leads to
1 compression of CN III leading to the eye moving down and out and a dilated pupil (first)
2 Compression of posterior cerebral artery leads to infarction of occipital lobe (contralateral homonymous hemianopsia)
3 Rupture of the paramedian artery leads to duret (brainstem) hemorrhage
106
What cells myelinate neurons in the CNS? PNS?
CNS - oligodendrocytesPNS - Schwann Cell
107
Are axons preserved in demyelinating disease?
Yes, however the conduction of the impulse is impaired
108
In general terms, what are leukodystrophies?
Problems with white matter
109
Inherited leukodystrophies involve enzymes with what types of functions?
production and maintenance of myelin
110
What enzyme is deficient in metachromic leukodystrophy and what does this lead to? What is the inheritance pattern? What cells are involved?
deficiency in arylsulfatasesulfatides cannot be degraded and accumulate in the lysosomes of oligodendrocytes (lysosomal storage disease)Autosomal Recessive inheritance
111
What enzyme is deficient in Krabbe disease, what does this lead to and what is the inheritance pattern? What cells are involved?
deficiency in galactocerebrosidase
galactocerebrosides accumulate in macrophages
Autosomal recessive inheritance
112
What function is impaired in adrenoleukodystrophy? what is the inheritance pattern?
impaired addition of coenzyme A to long-chain fatty acids.
| Accumulation of fatty acids damages adrenal glands and white matter of the brainX-linked
113
What happens in multiple sclerosis? (type of disease, what is damaged...not symptoms)
Autoimmune destruction of CNS myelin and oligodenrocytes. Leukodystrophy
114
MS more common in men or women?
women
115
What genetic marker is associated with MS?
HLA-DR2
116
In what regions is MS most common?
Away from the equator (Environmental trigger)
117
How does MS present (general terms not specific symptoms)
relapsing neurologic deficits with periods of remission (multiple lesions in time and space)
118
What are 6 clinical features of MS
1 blurred vision in one eye (optic nerve).
2 Vertigo and scanning speech mimicking alcohol intoxication (Brainstem).
3 internuclear opthalmoplegia (MLF).
4 Hemiparesis or unilateral loss of sensation (cerebral white matter, usually periventricular).
5 Lower extremity loss of sensation or weakness (spinal cord).
6 Bowel, bladder, and sexual dysfunction (autonomics)
119
How is diagnosis of MS made? what are the findings?
MRI reveals plaques (areas of white matter demyelination)
LP shows increase lymphocytes, increase immunoglobulins with oligoclonal IgG bands on high resolution electrophoresis, and myelin basic protein
120
What does gross examination show in MS?
Shows gray-appearing plaques in the white matter
121
How are acute MS attacks treated? what does long term treatment involve?
Acute attacks are treated with high does steroids
| long-term treatment with interferon beta slows progression
122
What is subacute sclerosing panencephalitis and what causes it?
It is a progressive, debilitating encephalitis leading to death due to slowly progressing, persistent infection of the brain by measles virus
123
When does infection occur in sclerosing panencephalitis and when doe neurological signs arise?
infection occurs in infancy and neurologic signs arise years later (during childhood)
124
What is subacute sclerosis panencephalitis characterized microscopically?
viral inclusions within neurons (gray matter) and oligodendrocytes (white matter)
125
What is Progressive multifocal leukoencephalopathy? What cells does it affect?
JC virus infection of oligodendrocytes (White matter)
126
What can cause Progressive multifocal leukoencephalopathy?
Immunosuppression (AIDS or Leukemia) leads to reactivation of the latent virus
127
How does Progressive multifocal leukoencephalopathy present?
with rapidly progressive neurologic signs (visual loss, weakness, dementia) leading to death.
128
What is central pontine myelinolysis?
Focal demyelination of the pons (anterior brain stem)
129
What causes central pontine myelinolysis?
rapid IV correction of hyponatremia
130
Who does central pontine myelinolysis occur in typically?
severely malnourished patients (alcoholics and patients with liver disease)
131
How does central pontine myelinolysis classically present?
as acute bilateral paralysis in which voluntary movement from head to toe is paralyzed except for eyes ("locked in" syndrome)
132
What are dementia and degenerative orders characterized by?
Loss of neurons within the gray matter; often due to accumulation of protein which damages neurons
133
Degeneration of which structures correlate with dementia and movement disorders?
cortex - dementia.
| brainstem and basal ganglia - movement disorders
134
What is degenerated in Alzheimer Disease?
cortex - most common cause of dementia
135
What are 4 clinical features of alzheimer disease?
1 slow onset memory loss (Begins with short-term memory loss and pregresses to long-term memory loss) and progressive disorientation
2 Loss of learned motor skills and language
3 changes in behavior and personality
4 patients become mute and bedridden
136
What is a common cause of death is AD?
infection
137
Do focal neurologic deficits occur early or late in AD?
LATE!!!
138
Are most cases of AD sporadic or inherited and what demographic are they seen in?
most are sporadic(95%) seen in the elderly
139
What are two risk factors for sporadic AD?
Age
e4 allele of apolipoprotein increases risk
e2 allele decreases risk
140
What are the two scenarios where early onset AD is seen and what causes it?
familial - associated with presenilin 1 and presenilin 2 mutations
Down Syndrome - occurs by age 40 and is due to APP being on Cr 21
141
What can be seen grossly in AD?
Diffuse cerebral atrophy with narrowing of the gyri, widening of the sulci, and dilation of the venticles (hydrocephalus ex vacuo)
142
Describe the structure of neuritic plaques in AD?
extracellular core comprised of AB amyloid with entangled neuritic processes
143
Where is AB amyloid derived from, whats its normal processing and what processing leads to amyloid?
derived from amyloid precursor protein which is coded on Cr21. APP normally undergoes alpha cleavage; beta cleavage results in AB amyoid
144
What enzymes are involved in breaking down APP?
normally alpha secretase, however can be beta secretase which leads to amyloidosis
145
What is the definition of dementia?
memory loss and cognitive dysfunction without any loss of consciousness
146
Describe cerebral amyloid angiopathy
AB protein can also deposit around blood vessels causing amyloid angiopathy which weakens the wall of blood vessels which increases the risk for hemmorrhage
147
What are neuofibrillary tangles and what protein is involved?
intracellular aggregates of fibers composed of hyperphosphorylated tau protein. tau is a microtubule associated protein
148
Where is there a loss of cholinergic neurons in AD?
basalis of meynert
149
How is diagnosis of AD made?
by clinical and pathological correlationpresumptive diagnosis is made clinically after excluding other causes and is confirmed only by histology at autopsy
150
What is vascular dementia a consequence of?
moderate global cerebral ischemia
151
What type of injury is vascular dementia and what is it due to?
Multifocal infarction and injury due to hypertension, atherosclerosis, or vasculitis2nd most common cause of dementia
152
What areas are most vulnerable to vascular dementia?
layers 3,5,6 of cortex and pyramidals of hippocampus
153
What is Pick Disease?
Degenerative disease of the frontal and temporal cortex; spares the parietal and occipital lobes
154
What is Pick Disease characterized by histologically?
ROUND aggregates of tau protein (pick bodies) in neurons of the cortex
155
Describe the symptomatic progression of pick disease
Behavioral (Frontal) and language (Temporal) symptoms arise early; eventually progresses to dementia
156
What happens in parkinsons disease (not symptoms)
Degenerative loss of DA neurons in the substantia niagra of the basal ganglia. nigrostriatal pathway of basal ganglia uses DA to initiate movement
157
What are the clinical features of parkinsons disease?
'TRAP'
Tremor - pill rolling tremor at rest; disappears with movement
Rigidity - cogwheel rigidity in the extremities
Akinesia/bradykinesia - slowing of voluntary movement ; expressionless face
Postural instability and shuffling gate
158
What dopamine receptors stimulate and what inhibit the cortex
D1 increases stimulation D2 Decreases inhibition
159
What does histology reveal in parkinsons?
loss of pigmented neurons in the substantia nigra and round, eosinophillic inclusions of alpha-synuclein (lewy bodies) in affected neurons
160
Is dementia a feature of early or late disease in parkinsons? what does the other suggest?
Dementia is common feature of LATE parkinsonsEarly onset dementia is suggestive of Lewy Body dementia
161
What Lewy body dementia characterized by?
characterized by dementia, hallucinations and parkinsonian features: histology reveals cortical Lewy Bodies
162
What happens in Huntingtons disease? (be specific)
degeneration of GABAergic neurons in the caudates nucleus of the basal ganglia
163
How is Huntingtons disease inherited what is the defect?and what expression property does it display?
Autosomal dominant inheritance, characterized by expanded trinucleotide repeats (CAG) in the huntingtin gene on chromosome 4 Further expansion of repeats during spermatogenesis leads to anticipation (future generations get earlier onset)
164
How does huntingtons present and progress?
presents with chorea that can progress to dementia and depression; average age at presentation is 40 yearscan also get aphetosis which is slow snake-like movements of the fingers
165
What is a common cause of death in Huntington's?
suicide
166
How does normal pressure hydrocephalus present?
urinary incontinence, gait instability, and dementia ("wet, wobbly, and wacky")
167
What can relieve symptoms in normal pressure hydrocephalus and what is a long term treatment?
lumbar puncture relieves symptoms and treatment involves a ventriculoperitoneal shunt
168
What is spongiform encephalopathy due to?
degenerative disease due to prion protein
169
What are the two forms of prion protein?
Prion protein is normally expressed in CNS neurons in an alpha helical configuration (PrPc)Disease arises with conversion to a beta pleated conformation (PrPsc)
170
What are the three modes of conversion in spongiform encephalopathy?
sporadic
inherited
transmitted
171
What is cellular damage characterized by in spongiform encephalopathy? What type of cells are affected?
Damage to neurons and glial cells is characterized by intracellular vacuoles
172
What causes increased CSF in normal pressure hydrocephalus?
loss of function of arachnoid granulations
173
How does creutzfeld-jakob disease usually arise?
Most cases are sporadic; rarely can arise due to exposure to prion infected human tissue (human growth hormone or corneal transplant)
174
How does CJD present?
presents as rapidly progressive dementia associated with ataxia (cerebellar involvement) and startle myoclonus periodic sharp waves (spikes) are seen on EEGResults in death usually in less than a year
175
What is variant CJD?
a special form of the disease related to exposure to bovine spongiform encephalopathy (mad cow disease)
176
What is familial fatal insomnia?
an inherited form of prion disease characterized by severe insomnia and an exaggerated startle response.
177
What is Amyloid Precursor Protein?
A membrane receptor with unknown function
178
What percentage of CNS tumors are metastatic vs primary?
50:50
179
In general terms describe the locational trends of adult vs child tumors
Tumors in adults usually occur above the tentorium and child CNS tumors generally occur below.
180
How doe metastatic CNS tumors present and what are 3 common sources?
present as multiple, well circumscribed lesions at the gray-white junction
Lung
Breast
Kidney
181
What are the most abundant glial cell?
astrocytes
182
Primary CNS tumors are classified according to cell type of origin, what are the five major cell types?
```
astrocytes (form BBB)
meningothelial
ependymal
oligodendrocytes
neuroectoderm
```
183
Do primary CNS tumors tend to metastasize?
they are locally destructive but rarely metastasize
184
What are the most common (3) CNS tumors in adults?
Glioblastoma multiforme
meningioma
schwannoma
185
What percentage of CNS cells are neurons vs glial?
50/50
186
What are the most common (3) CNS tumors in children?
pilocytic astrocytoma
ependymoma
medulloblastoma
187
What cell type is involved in Glioblastoma multiforme? what is the grade and malignant/benign? prognosis?
Malignant, high-grade tumor of astrocytespoor prognosis
188
What is the most common primary malignant CNS tumor in adults?
Glioblastoma multiforme
189
Describe the gross involvement of the brain in glioblastoma multiforme?
Usually arises in the cerebral hemisphere; characteristically crosses the corpus callosum "butterfly lesion"
190
Describe the histology seen in Glioblastoma multiforme?
characterized by regions of necrosis surrounded by tumor cells (pseudopalisading) and endothelial cell proliferation; tumor cells are GFAP positive
191
What is GFAP?
an intermediate filament in glial cells
192
What cell type is involved in a meningioma, malignant/benign? who is it most commonly seen in?
Benign tumor of arachnoid cellsmore commonly seen in women; rare in children
193
What hormone receptor are meningioma positive for?
Estrogen
194
How doe meningiomas present?
may present as seizures; tumor compresses, but does not invade, the cortex
195
What does imaging reveal in meningioma?
round mass attached to the dura
196
What is the most common benign primary CNS tumor in adults?
meningioma
197
What does histology show in meningioma?
whorled patter; psamomma bodies may be present
198
What cell type is affected in schwannoma? malignant/benign?
benign tumor of schwann cells
199
Describe the structural involvement of schwannoma?
Involves crainial or spinal nerves; within the cranium, most frequently involves CN VIII at the cerebellopontine angle (presents as loss of hearing and tinnitus)
200
What cell marker are schwannomas positive for?
S-100
201
what disease leads to bilateral schwannomas?
neurofibromatosis type 2
202
what cell type is involved in oligodendroglioma? malignant/benign? kids/adults?
malignant tumor of oligodenrocytes
203
What does imaging reveal in oligodendroglioma?
reveals a calcified tumor in the white matter, usually involving the frontal lobe; may present with seizures
204
What is the classic appearance of cells on biopsy of oligodendroglioma?
Fried egg appearance
205
What cell type is affected in pilocytic astrocytoma? malignant/benign? kids/adults? where?
benign tumor of astrocytes in children usually arises in the cerebellum
206
What does imaging reveal in pilocytic astrocytoma?
cystic lesion with a mural nodule
207
What does biopsy reveal in pilocytic astrocytoma?
Rosenthal fibers (thick eosinophilic processes of astrocyte) and eosinophilic granular bodies;
208
What are tumor cells positive for in pulocytic astrocytoma?
GFAP
209
What cell type is affected in medulloblastoma? malignant/benign? adults or kids?
Malignant tumor derived from the granular cells of the cerebellum (neuroectoderm) usually arises in children
210
What does histology reveal in medulloblastoma?
reveals small, round blue cells; Homer-Wright rosettes may be present (small round blue cells wrap around pink areas of neuritic processes)
211
What is the prognosis in medulloblastoma?
poor prognosis; tumor grows rapidly and spreads via CSF
212
What is a metastasis to the cauda equina from the brain termed?
drop-metastasis
213
What cell type is affected in ependymoma? malignant/benign? kids/adults?
Malignant tumor of ependymal cells usually seen in children
214
Where do ependymomas commonly arise and what do they present with?
4th ventricle and may present with hydrocephalus
215
What are a characteristic finding on biopsy in ependymoma?
perivascular pseudorosettes
216
What are ependymal cells?
They line the ventricular spaces
217
Where do craniopharyngiomas arise from? malignant/benign?
Arise from epithelial remnants of Rathke's pouchIt is benign, but tends to recur after resection
218
How does craniopharyngioma present?
supratentorial mass in a child or young adult; may compress the optic nerve chiasm leading to bitemporal hemianopsia
219
What are commonly seen on imaging in craniopharyngioma?
calcifications (derived from "tooth-like" tissue)
