Chapter 28: The CNS Flashcards
1
Q
Neuronal response to injury within 12-24 hours
A
Red neurons
Show shrinkage of cell body, pyknosis, loss of nucleolus, loss of nissl substance, with intense eosinophilia of cytoplasm
2
Q
Axonal reaction to injury in which nissl substance is removed from the center of the cell to the periphery
A
Central chromatolysis
Other axonal reactions to injury include enlarged/rounded cell body, peripheral displacement of nucleus, and enlarged nucleolus
3
Q
Primary example of neuron intracytoplasmic inclusion
What clinical conditions are neuronal intracytoplasmic inclusions seen in?
A
Lipofuscin
Rabies negri bodies, alzheimer nuerofibrillary tangles, parkinson lewy bodies, CJD
4
Q
Clinical examples of neuronal intranuclear inclusions
A
Herpes cowdry bodies
CMV has both intranuclear and cytoplasmic inclusions
5
Q
Most important histopathologic indicator of CNS injury, regardless of etiology
A
Gliosis (astrogliosis)
Characterized by hypertrophy and hyperplasia of astrocytes (now called gemistocytes
6
Q
In what conditions might you see an alzheimer type 2 astrocyte?
A
Hyperammonemia (chronic liver disease)
Wilson disease
Hereditary metabolic disorder of urea cycle
[characteristics include enlarged nucleus, pale staining central chromatin, intranuclear glycogen droplet, prominent membrane and nucleolus]
7
Q
Thick, elongated, brightly eosinophilic, irregular structures occurring within astrocytic processes and containing 2 heat shock proteins: alpha-B-crystallin and HSP27 as well as ubiquitin
A
Rosenthal fibers
8
Q
Polyglucosan bodies that are PAS+ associated with increasing age and representative of degenerative change
A
Corpora amylacea
9
Q
Surface markers of microglia
A
CR3, CD68 [same as peripheral macrophages]
10
Q
One way in which microglia respond to injury is neuronophagia - what is this process?
A
Microglia congregate around cell bodies of dying neurons
11
Q
Other glial responses to injury include ________ in PML, which develop intranuclear inclusions
These cells develop glial cytoplasmic inclusions in multiple sytem atrophy (MSA) that contain _________, the product also seen in Parkinsons Lewy bodies
A
Oligodendrocytes
Alpha-synuclein
12
Q
Response of ciliated ependymal cells (line the ventricles) to injury
A
Disruption of ependymal lining and proliferation of subependymal astrocytes —> ependymal granulations
[seen in CMV]
13
Q
Difference between vasogenic and cytotoxic cerebral edema
A
Vasogenic:
Increased extracellular fluid due to BBB disruption and increased vascular permeability; OFTEN FOLLOWS ISCHEMIC INJURY
Cytotoxic:
Increased intracellular fluid secondary to neuronal, glial, or endothelial cell membrane injury; characteristic appearance of flattened gyri, narrowed sulci, compressed ventricles, and potential complication of HERNIATION
14
Q
Responses of the body to increased CSF
A
Absorption by transventricular and nerve root sleeves
Dilation of frontal and temporal horns
Thinning of cerebral mantle
Stretching/perforation of septum pellucidum
Enlargement of 3rd ventricle downwards
Increased ICP noted as papilledema
15
Q
In what condition might hydrocephalus be due to increased production of CSF?
A
Choroid plexus papilloma
16
Q
What is communicating hydrocephalus?
A
Communicating (non-obstructive):
CSF is not absorbed properly at the dural sinus level, thus the ventricles tend to be symmetrically dilated
17
Q
What is hydrocephalus ex vacuo? How is this distinguished from other cases of hydrocephalus?
A
Dilation of ventricles to compensate for shrinkage of brain substance due to other cause (atrophy with age, stroke or other injury, chronic neurodegenerative disease)
CSF pressure is normal in these cases
18
Q
Classic triad of symptoms seen with normal pressure hydrocephalus
A
“Wet, wobbly, wacky”
Urinary incontinence, gait disturbance (magnetic), dementia
19
Q
3 principle causes of increased ICP
A
Generalized brain edema
Expanding mass lesion (tumor, abscess, hemorrhage)
Increased CSF volume
20
Q
What are the 3 types of herniation
A
Subfalcine (cingulate): cingulate gyrus displaced under falx
Transtentorial (uncal): medial aspect of temporal lobe compressed against the tentorium
Tonsillar: cerebllar tonsils displaced through foramen magnum; life threatening due to respiratory and cardiac center compression
21
Q
Which type of herniation involves risk to CN3? What are the effects when CN3 is involved?
A
Transtentorial (uncal) herniation — dilated pupil and impaired eye movement
22
Q
What is kernohan’s notch phenomenon
A
Result of compression of cerebellar peduncle against the tentorium cerebelli due to transtentorial herniation
Causes ipsilateral hemiparesis or hemiplegia
[if you have a right hemisphere transtentorial herniation, you have a kernohan’s notch phenomenon in left cerebellar peduncle, which results in right-sided motor impairment]
23
Q
______ = type of hemorrhage in midbrain and pons associated with progression of transtentorial herniation
A
Duret hemorrhage
24
Q
And infarct in the CNS results in what type of necrosis?
A
Liquifactive
25
What general pathology accounts for most CNS malformations?
Neural tube defects [usually folate deficiency]
26
Diverticulum of disorganized brain tissue extending through defect in cranium; usually posterior fossa
Encephalocele
27
Conditions associated with microcephaly
Chromosomal abnormalities
Fetal alcohol syndrome
HIV-1
Zika virus
28
What forebrain anomaly is associated with entrapment of meningeal tissue?
Polymicrogyria
29
Neuronal heterotopias are collections of neurons in innappropriate places (i.e., ventricular surface)along the path of migration; commonly associated with what condition?
Epilepsy
30
Changes in Filamin A and DCX proteins on the X-chromosome leads to what anomalies in males vs. females?
Males: lissencephaly
Females: subcortical band heterotopias
31
Anomaly characterized by incomplete separation of cerebral hemispheres across midline
Holoprosencephaly
32
A “bat-wing” appearance of the lateral ventricles on imaging may indicate what forebrain anomaly?
Agenesis of corpus callosum
33
Misshapen midline cerebellum with downward extension of vermis through foramen magnum
Arnold chiari malformation type II
[commonly associated with hydrocephalus and myelomeningocele]
34
What is the dandy-walker malformation
Enlarged posterior fossa; expanded roofless fourth ventricle (cerebellar vermis absent) - replaced by cyst with ependymal lining that is contiguous with leptomeninges on outer surface
35
Hypoplasia of vermis, elongation of cerebellar peduncles, altered brainstem shape
Joubert syndrome
[“molar tooth sign”]
36
Fluid-filled cleft-like cavity in the inner portion of the cord - may lead to loss of pain/temp in upper extremities
Syringomyelia (Syrinx)
37
Type of hemorrhage usually seen in germinal matrix of premature infants at the junction between thalamus and caudate nucleus; may lead to subarachnoid hemorrhage
Intraparenchymal hemorrhage
38
Perinatal brain injury characterized by infarcts in supratentorial white matter; occurs in premature infants and consists of chalky yellow plaques due to necrosis and calcification
Periventricular leukomalacia
39
Perinatal brain injury in which there is extensive ischemic damage of both white and gray matter leading to large destructive cystic lesions
Multicystic encephalopathy
40
Perinatal ischemic lesions in the depths of the sulci leading to thinned out gliotic gyri
Ulegyria
41
Repeated blows o the head increase risks for developing CTE, leding to progressive loss of normal brain matter and an abnormal buildup of a protein called ____
Tau
[deposition of hyperphosphorylated tau protein as neurofibrillary tangles, astrocytic tangles, and neurites in striking clusters around small blood vessels of the cortex, typically at sulcul depths]
Note that beta-amyloid may also be identified in some cases
42
Type of CNS injury characterized by axonal swelling with out without focal hemorrhagic lesions; appears within hours but persists much longer; visualized by silver stain or APP and alpha-synuclein immunostains
Diffuse axonal injury (DAI)
43
What vascular territory was likely affected if a pt presents with contralateral leg weakness consistent with upper motor neuron injury?
Anterior cerebral artery
[would also be likely with “alien hand” syndrome]
44
What vascular territory was likely affected if pt presents with contralateral homonymous hemianopia?
Posterior cerebral artery
45
What vascular territory is the most common site for infarcts and ischemia due to its large area of coverage?
Middle cerebral a.
46
Gaze preference toward the side of the lesion would indicate infarct in what vascular territory?
Middle cerebral a.
[may also see aphasia, hemineglect, face-arm or face-arm-leg sensorimotor loss]
47
A watershed infarct of the ACA-MCA would have what clinical effects?
Proximal arm and leg weakness
Transcortical aphasia; language issues
48
A watershed infarct of the MCA-PCA would have what clinical effects?
Deficits in higher order visual processing
49
What is the most common cause of thrombotic occlusions?
Atherosclerosis
50
Minute aneurysms in the basal ganglia associated with chronic HTN
Charcot-Bouchard microaneurysms
51
Dementia, gait abnormalities, and pseudobulbar signs are associated with infarctions caused by what?
Malignant HTN
52
Most frequent cause of clinically significant subarachnoid hemorrhage
Rupture of saccular (berry) aneurysm
[most fequently found in anterior circulation — usually anterior communicating artery]
53
Within the first few days after a subarachnoid hemorrhage, regardless of etiology, there is increased risk of additional ischemic injury from _____ affecting vessels bathed in extravasated blood
Vasospasm
54
What are arteriovenous malformations?
Occur in subarachnoid space (more common in males) - may extend into brain parenchyma or exclusively in parenchyma
Tangle, wormlike vascular channels with prominent pulsatile arteriovenous shunting (no intervening capillary beds!) with high blood flow
55
Most common vessels affected by arteriovenous malformations
MCA and posterior branches
56
Most common route of infection to CNS
Hematogenous — arterial primarily but retrograde venous spread via anatomosing facial veins is possible
57
Herpes simplex and zoster route of infection to CNS
Produces latent infection of SENSORY ganglia, replicates in schwann cells, and ascends to CNS within SENSORY nerves
58
Rabis virus route of infection to CNS
Virus binds at or near ACh receptors at the NMJ and ascends to the CNS via MOTOR nerves
59
Complication of pneumococcal meningitis
Chronic adhesive arachnoiditis
60
What complication of meningitis can lead to hydrocephalus?
Leptomeningeal fibrosis
61
What is waterhouse friderichsen syndrome
Complication of bacterial meningitis consisting of meningococcemia —> adrenal hemorrhage —> death
62
Morphology of N. meningiditis
Gram-negative diplococci
63
Morphology of S. pneumoniae
Gram-positive dipolococci
64
Morphology of H. influenzae
Gram-negative pleomorphic
65
Morphology of staph infection
Gram-positive cocci
66
Morphology of E. Coli
Gram-negative bacilli
67
CSF findings in viral meningitis in terms of CSF appearance, pressure, dominant cell type, glucose and protein content
Clear CSF, normal or increased pressure
Early on will see PMNs, later get lymphocytes
Glucose normal or decreased
Protein normal or decreased
68
CSF findings in bacterial meningitis in terms of CSF appearance, pressure, dominant cell type, glucose and protein content
Opaque CSF; increased pressure
PMNs dominant cell type
Decreased glucose, increased protein
69
CSF findings in fungal meningitis in terms of CSF appearance, pressure, dominant cell type, glucose and protein content
Clear CSF, Increased pressure
Early on will see PMNS, later lymphocytes
Decreased glucose, increased protein
70
CSF findings in cranial abscess infection
High WBC
High protein
Normal glucose
71
Bacterial or fungal infection of skull bones or sinuses spread to subdural space
Subdural empyema
72
Clinical manifestations of N.meningiditis infection
Rapidly progressive septicemia with fever, hypotension, DIC, petechial and purpuric lesions
73
Hemorrhagic skin lesions seen in N.meningiditis infections which progress to gangrene, occuring in distal portions of limbs
Purpura fulminans
74
What conditions might lead to chronic cases of meningitis?
Tuberculosis
Neuroborreliosis
Neurosyphilis
75
Condition causing insidious, but progressive mental deficits associated with mood alterations (delusions of grandeur), that terminate in severe dementia; may also see perivascular iron deposits
Paretic neurosyphilis
[may also see granular ependymitis and associated hydrocephalus]
76
Potential complication of treponema pallidum infection consisting of damage to the sensory nerves, impaired joint position sense and resultant ataxia, loss of pain sensation (Charcot joints), lightening pains, and absence of deep reflexes
Tabes dorsalis
77
In what type of infection would you see Cowdry type A intranuclear viral inclusions in neurons and glia?
HSV-1
78
Effects of in utero CMV infection
Periventricular necrosis, severe brain destruction, microcephaly, and periventricular calcification
Localizes in paraventricular subependymal regions!
79
What clinical feature of rabies is diagnostic?
Paresthesias around wound
[also see negri bodies in purkinje cells]
80
Microglial nodules with multinucleated giant cells would be indicative of what type of infection?
HIV (chronic)
81
What is IRIS?
Immune reconstitution inflammatory syndrome:
Paradoxical deterioration after starting antiviral therapy —> exuberant inflammatory response —> paradoxical exacerbation of sxs from opportunistic infections
82
What type of infection is associated with progressive multifocal leukoencephalopathy (PML)?
JC polyoma virus — which almost exclusively occurs in immunosuppressed individuals
83
Subacute sclerosing panencephalitis (SSPE) is associated with what type of infection?
This is a rare, progressive syndrome with cognitive decline, spasticity of limbs, etc. that occurs months to years after early acute infection with MEASLES (rubeola)
84
Patients with DM are more susceptible to fungal meningoencephalitis with what species?
Mucormycoses
85
Clinical presentation of CJD
Rapidly progressive dementia with startle myoclonus
86
Histologic findings in someone with CJD
Neuron with vacuoles representing spongiform changes
Kuru plaques are PAS+ and Congo red +
87
CHANGes mnemonic for middle cerebral artery signs and symptoms
Contralateral paresis and sensory loss in face and arm
Homonymous hemianopsia
Aphasia
Neglect
Gaze preference toward side of lesion
88
Autoimmune demyelinating disorder with relapsing/remitting episodes typically initially presenting as unilateral visual impairment due to optic neuritis
MS
89
Genes associated with MS
DR2
IL-2 and IL-7 receptor genes [because it is considered a T cell mediated disease]
90
CSF changes associated with MS
Mildly elevated protein
Moderate pleocytosis
IgG increased
Oligoclonal IgG bands (gamma region) in immunoelectrophoresis
91
Synchronous bilateral optic neuritis and spinal cord demyelination with antibodies to aquaporins
Neuromyelitis optica
92
Diffuse monophasic demyelinating disease that follows either viral infection or rarely viral immunization, presents as a perivenous encephalomyelities
Acute disseminated encephalomyelitis (ADEM)
93
Fulminant syndrome of CNS demyelination seen in young adults and children following recent upper respiratory infection
Acute necrotizing hemorrhagic encephalomyelitis (ANHE)
94
Symmetric demyelination involving basis pontis and portions of pontine tegmentum following overly rapid correction of hyponatremia — leads to rapidly evolving quadriplegia (Locked in syndrome)
Central pontine myelinolysis
95
Most common cause of dementia in the elderly
Alzheimers disease
96
Asymmetric atrophy of frontal and temporal lobes with sparing of posterior 2/3 of superior temporal gyrus characterized by early onset of behavioral changes with alterations in personality and language disturbance
Pick disease
97
Disease causing widespread neuronal loss, characterized by truncal rigidity with disequilibrium and nuchal dystonia; pseudobulbar palsy and abnormal speech, ocular disturbances including vertical gaze palsy progresing to difficulty with all eye movements; mild progressive dementia
Progressive supranuclear palsy
[see globose neurofibrillary tangles - 4R tau straight filaments]
98
Parkinsonism describes a condition in which there is damage to the ______ _____ system
Nigrostriatal dopaminergic
99
Inheritance of Parkinson disease
Autosomal dominant: alpha synuclein; Chr4q21
[Juvenile autosomal recessive parkin]
100
Morphology of Parkinson disease
Pallor of substantia nigra and locus ceruleus
Lewy bodies containing alpha synuclein
101
Characteristic clinical feature of dementia with lewy bodies
Hallucinations
102
Sporadic disorder affecting a number of different systems in the brain; characterized by cytoplasmic inclusions of alpha-synuclein in oligodendrocytes
Multiple system atrophy
103
Inheritance of Huntington disease
Autosomal dominant: Polyglutamine trinucleotide repeat (CAG) on Chr4p16.3
104
What is “anticipation” and what disease is it associated with?
Huntington disease: Repeat expansions during spermatogenesis leads to earlier onset (juvenile form)
105
CAG expansion in Huntington disease seems to produce toxic gain of function on Huntingtin protein - which aggregates to form intranuclear inclusions.
The brain is small, with striking atrophy of the ____ ____, and later the ________.
The globus pallidus is secondarily atrophied, as well as the frontal lobes
Caudate nucleus; putamen
[overall severe loss of striatal neurons - most marked in caudate nucleus]
106
Disease associated with GAA trinucleotide repeat on Chr9 with autosomal recessive inheritance pattern
Friedrich ataxia
107
Autosomal recessive condition associated with mutations in ATM gene on Chr11, which encodes a kinase with critical role in orchestrating cell response to dsDNA breaks - resulting in increased sensitivity to x-rays
Ataxia-Telangiectasia
108
Disease associated with mutations in SOD1, resulting in adverse gain of function
ALS
[may also see TDP-43, as with frontotemporal lobar degenerations]
109
A deficiency in _____ may lead to numbness, tingling, and slight ataxia in LE within a few weeks; histological signs include vacuoles in axons of both ascending tracts of posterior columns and descending pyramidal tracts
Vitamin B12
110
Most common leukodystrophy
Metachromatic leukodystrophy — deficiency in arylsulfatase
111
Leukodystrophy characterized by deficiency in galactocerebroside beta-galactosidase
Krabbe disease
112
what do most patients with Friedrich ataxia die from?
Complications of cardiomyopathy [arrhythmias, CHF, etc]
113
Generally well-circumscribed tumor, often cystic with a mural nodule; predisposing factor is NF1
Pilocytic astrocytoma
114
Characteristic feature of pilocytic astrocytoma on histology
Marked increase in rosenthal fibers
[also eosinophilic granular bodies]
115
Most common primary brain neoplasm
Glioblastoma
116
Genetic changes associated with primary vs. secondary glioblastoma
Primary: EGFR and PTEN
Secondary: TP53, IDH1 and IDH2
117
Imaging and histologic markers of glioblastoma
Contrast ring enhancing lesions; hypodense central necrosis
Histology: serpentine patterns of necrosis, pseudopalisading, vascular/endothelial proliferation
118
Tumor found primarily in adults and characterized by calcification, usually restricted to the cortex
Oligodendroglioma
119
Genetic changes associated with favorable prognosis in oligodendroglioma
IDH1 and IDH2
1p19q loss
120
4 groups associated with medulloblastoma as they relate to prognosis
WNT
SHH
Group 3: MYC amp. and Chr17
Group 4: Chr i17q, no MYC
Worst prognosis is group 3, best prognosis is WNT type
121
Characteristics of primary CNS lymphoma
Usually in Immunosuppressed individuals; primary often multifocal periventricular spread
B-cell origin CD20+; often latently infected with EBV
122
Primary brain tumor that occurs along midline and is more common in Japanese populations
Germ cell tumors
123
Tumor associated with changes in NF2 and TRAF7; EMA+
Meningioma
124
Gross and histological findings in brain with meningioma
Calcified psammoma bodies; en plaque — sheet like spread of tumor along surface of tumor
Histo: whorled clusters of monotonous cells; psammoma bodies
125
What type of tumor tends to worsen in pregnancy?
Meningiomas
126
Most common metastatic brain tumors
Lung, breast, melanoma
[also kidney, GI]
127
Subacute cerebellar degeneration is a paraneoplastic syndrome associated with ____ antibodies with destruction of purkinje cells, gliosis, and mild chronic inflammatory infiltrate. It is seen in women with ovarian, uterine, or breast carcinoma
PCA-1 Ab (anti-yo)
128
What paraneoplastic syndrome often accompanies neuroblastoma in kids?
Eye movement disorders
129
Molecular changes associated with the limbic encephalitis paraneoplastic syndrome
ANNA-1 Antibody (small cell carcinoma of lung)
NMDA receptor (ovarian teratomas)
VGKC complex Ab
130
Syndrome associated with pheochromocytoma, neurofibromatosis, cafe au lait spots, and optic nerve glioma
NF1
131
Syndrome associated with pheochromocytoma, paraganglioma, renal cell carcinoma, hemangioblastoma, pancreatic endocrine neoplasms
VHL
132
Gene/protein associated with neurofibromatosis type I
NF1; neurofibromin
[negatively regulates RAS signaling]
133
Gene/protein associated with neurofibromatosis type II
NF2; merlin
[integrates cytoskeletal signaling/neurofibromas and acoustic neuromas]
134
Autosomal dominant disease associated with polycythemia, hemangioblastomas of CNS (cerebellum and retina); associated with renal cell carcinoma and pheochromocytoma
VHL
135
A 28-year-old man undergoes induction chemotherapy for acute myelogenous leukemia. A week later he becomes severely pancytopenic, with WBC count of 1320/microliter, Hgb 7.9 g/dL, and platelet count 72,000/microliter. Head CT scan shows a right parietal hemorrhage. MR imaging and angiography reveals a right middle cerebral arterial thrombosis with right parietal hemorrhagic infarction. Which of the following infectious agents is most likely to cause these findings?
```
A. Herpes Simplex Virus
B. Toxoplasma gondii
C. HIV
D. CMV
E. Aspergillus flavus
```
E. Aspergillus flavus
Aspergillus loves to invade blood vessels and produce thrombosis. Neutropenia is a risk for aspergillosis. The portal of entry may be the lung, but a fungemia can disseminate the infection to the brain.
136
A 22-year-old primigravida has noted no fetal movement at 18 weeks gestation. Fetal ultrasound examination shows marked hydrops fetalis and organomegaly. There is extensive cerebral necrosis and periventricular calcification. Infection with which of the following organisms is most likely to produce these findings?
```
A. CMV
B. HSV
C. HIV
D. EBV
E. Rubeola
```
A. CMV
CMV is the 'C' in the TORCH mnemonic for congenital infections. congenital CMV is a disseminated infection that often involves the CNS and can produce extensive prenatal CNS damage, such as periventricular leukomalacia. Dissemination of the infection to other organs accounts for organomegaly.
137
A 48-year-old woman has the sudden onset of a severe headache. On physical examination there are no localizing neurologic signs, but she is minimally responsive. A cerebral angiogram demonstrates marked narrowing of cerebral artery branches near the base of the brain, consistent with vasospasm, but no intraparenchymal hemorrhage is present. Laboratory studies show a serum urea nitrogen of 50 mg/dL. An ultrasound scan of the abdomen shows bilaterally enlarged cystic kidneys. Which of the following is the most likely pathologic finding in this woman?
```
A. Acute meningitis
B. Severe atherosclerosis
C. Arteriosclerosis
D. Cerebral edema
E. Subarachnoid hemorrhage
```
E. Subarachnoid hemorrhage
The blood irritates the arteries. This effect is often delayed by several days following the initial hemorrhagic event. Berry aneurysms are located in the circle of Willis at the base of the brain, and rupture leads to extravasation of blood into the subarachnoid space. Her renal scan suggests a diagnosis of autosomal dominant polycystic kidney disease (ADPKD). About 10% of persons with ADPKD develop berry aneurysms.
138
A 50-year-old man was involved in a vehicular accident in which he was not wearing any restraint device and struck his head against the windshield of his van. He did not lose consciousness at that time or at any point thereafter. Physical examination showed a minor contusion to his forehead. However, a month later he begins complaining of headaches, becoming irritable and acting strangely. Which of the following intracranial vascular abnormalities most likely developed in this man?
```
A. Epidural hematoma
B. Subdural hematoma
C. Cerebral contusions
D. Subarachnoid hemorrhage
E. Intracerebral hematoma
```
B. Subdural hematoma
The continued presence of a subdural hematoma leads to the problems described, even if it is relatively small. The trauma led to a rupture of dural bridging veins. Venous bleeding may be slow, so that the hematoma accumulated over time. When the clot begins to organize, it may imbibe additional fluid and increase in size. Rebleeding may occur through delicate capillaries in the organizing wall of the clot. Neurosurgical intervation is required to remove the clot.
139
A 14-year-old boy is brought to the emergency room following an accident in which he hit his head against a concrete wall. He was initially unconscious but then regained alertness 5 minutes later. However, an hour later in the emergency room, he is comatose, and skull radiograph reveals a linear skull fracture of the temporal-parietal region on the left. Which of the following is the most likely develop in this boy?
```
A. Subdural hematoma
B. Epidural hematoma
C. Ruptured berry aneurysm
D. Cerebral edema with herniation
E. Contusion of frontal lobes
F. Sagittal sinus thrombosis
```
B. Epidural hematoma
The 'lucid' interval is classic for an epidural hematoma from a tear of the middle meningeal artery. The hematoma accumulates rapidly, because the bleeding is arterial
140
A 45-year-old man has had a severe, intractable headache for a week. Physical examination reveals papilledema on the right. A head CT scan shows marked right to left midline shift. MR imaging shows a 6 cm enhancing mass lesion in the right parietal region with marked surrounding edema. He then develops a dilated pupil on the right. Which of the following vascular lesions is he most likely to have?
A. Superior sagittal sinus thrombosis
B. Right cerebellar hemispheric hemorrhage
C. Pontine hemorrhages
D. Thrombosis of the posterior cerebral artery
E. Diffuse subarachnoid hemorrhage
C. Pontine hemorrhages
The cerebral hemispheric swelling leads to herniation beneath the tentorium, which damages small perforating vessels and results in Duret hemorrhages in the pons and midbrain. The hemispheric lesion that led to these findings is most likely a high grade glioma.
141
A 50-year-old woman suddenly loses consciousness. On examination in the emergency department, her temperature is 37°C, pulse 79/minute, respirations 18/minute, and blood pressure 160/95 mm Hg. A head CT scan shows a 4 cm area of bright attenuation in the left basal ganglia region. There is effacement of the lateral ventricles and a shift of the midline to the right. Through which of the following mechanisms is death in the patient most likely to occur?
```
A. Cerebellar tonsillar herniation
B. Intraventricular hemorrhage
C. Widespread metastases
D. Dissemination of infection
E. Extensive watershed infarction
```
A. Cerebellar tonsillar herniation
She has a hypertensive hemorrhage, and the large collection of blood produces a mass effect with downward pressure to the posterior fossa to produce herniation. Recent hemorrhage appears bright with CT images.
142
A 66-year-old man has had general paresis with increasing loss of higher mental functions for the past 3 years. On physical examination he walks with a widened gait, and he has a positive Romberg test. Laboratory studies show that a VDRL is positive on cerebrospinal fluid obtained by lumbar puncture. The CSF protein and glucose are normal, and there is 1 mononuclear cell present. Which of the following pathologic findings is most likely to be present in his spinal cord?
```
A. Anterior horn cell loss
B. Hemorrhage
C. Plaques of demyelination
D. Vacuolar myelopathy
E. Dorsal column atrophy
```
E. Dorsal column atrophy
He has neurosyphilis. This helps to explain the term 'tabes dorsalis' in syphilis. T. pallidum infection leads to endarteritis in brain (as well as in the aorta). T. pallidum infection can also lead to chronic meningitis.
143
A 46-year-old woman has experienced severe headaches, worsening over the past 2 months. She has noted difficulty moving her left arm during the past day. On physical examination papilledema is present, worse on the right. A lumbar puncture is performed, and the CSF reveals a protein of 190 mg/dL, glucose of 68 mg/dL (serum glucose is 100 mg/dL), and a cell count of 5 WBCs/microliter (4 mononuclears and 1 PMN) and 6 RBCs/microliter. Through which of the following mechanisms are these findings most likely to be produced?
A. Blockage of lymphatics by metastatic tumor
B. Overproduction of CSF
C. Storage disease with neuronal cell loss
D. Hyperosmolar coma with diabetes mellitus
E. Edema adjacent to a primary neoplasm
E. Edema adjacent to a primary neoplasm
The new vessels (neovascularization) at the margin of a tumor, particularly a rapidly-growing neoplasm such as a glioblastoma, or in the wall of an abscess, lack an effective blood-brain barrier, leading to cerebral edema.
144
A 48-year-old woman has had headaches for the past 4 months. On examination she is afebrile. The only neurologic deficit is loss of cranial nerve I function on the right. A head CT scan shows a 6 cm circumscribed solid mass in the right anterior fossa. What is the most likely cell of origin for this mass?
```
A. Microglial cell
B. Neuron
C. Neuroblast
D. Meningothelial cell
E. Breast ductal epithelial cell
```
D. Meningothelial cell
Arachnoidal meningothelial cells give rise to meningiomas. The subfrontal location extrinsic to the brain in the fossa is consistent with a meningioma.
