CNS Flashcards
1
Q
Pseudotumor cerebri
A
- Increased intracranial pressure due to decreased CSF reabsorption
- Papilledema, headache, vision change
- Risk factors: hypothyroidism, Cushing’s, OCPs, isotretinoin, tamoxifen
- Flattening of posterior globe on MRI
2
Q
Subfalcine cerebral herniation
A
- Cingulate gyrus herniates under falx cerebri
- Confusion and drowsiness; possible contralateral LE weakness and urinary incontinence w/ ACA compression
3
Q
Uncal cerebral herniation
A
- Medial temporal lobe herniates thru tentorium cerebelli
- Midbrain compression (Duret hemorrhages)
- CN 3 compression (down-and-out eye deviation), pupil dilation
- PCA compression (occipital lobe infarct, visual disturbance)
- Hemiparesis ipsilateral to mass
4
Q
Tonsillar cerebral herniation
A
- Cerebellar tonsils herniate into foramen magnum (“coning”)
- Cardiorespiratory arrest
5
Q
Hydrocephalus
A
- Increased CSF volume —> ventricular enlargement
- Noncommunicating hydrocephalus may be caused by pineal gland tumor or aqueduct of Sylvius (b/w 3rd and 4th ventricles) blockage
- Communicating hydrocephalus: can result from dural venous sinus thrombosis
- Increased head circumference in newborns
- Hydrocephalus ex vacuo: ventricular enlargement w/ Alzheimer’s-related cerebral atrophy
- Normal pressure hydrocephalus: wide-based gait, urinary incontinence, dementia
- Causes: prior trauma/surgery, prior subarachnoid hemorrhage
6
Q
Arnold-Chiari malformation
A
- Caudal extension of medulla and cerebellar vermis thru foramen magnum
- Noncommunicating hydrocephalus
- Platybasia (flattened base of skull)
- Associated w/ meningomyelocele, syringomyelia
7
Q
Dandy-Walker malformation
A
- Partial or complete absence of cerebellar vermis
- Cystic dilation of 4th ventricle ‘
- Noncommunicating hydrocephalus
8
Q
Syringomyelia
A
- Sx starting in 20s-30s
- Syrinx (fluid-filled cavity) w/in cervical spinal cord expands and causes degeneration of spinal tracts
- Associated w/ Arnold-Chiari malformation
- Disruption of spinothalamic tracts (pain and temp loss in “cape-like” distribution)
- Disruption of anterior horn cells (atrophy of intrinsic muscles of hand)
- Disruption of ANS
- Charcot joint
9
Q
Neurofibromatosis
A
- Autosomal dominant
- Mutation on chr 17 (neurofibromin) or 22 (merlin), both tumor suppressors
- Both types: café-au-lait spots, pigmented cutaneous/subQ neurofibromas (except palms and soles)
- Type 1: Lisch nodules (pigmented hamartoma of iris), axillary/inguinal freckling, pigmented plexiform neurofibromas, pheochromocytoma, Wilms tumor (both w/ HTN), CML
- Type 2: bilateral acoustic neuromas, meningiomas, spinal schwannomas, juvenile cataracts
10
Q
Tuberous sclerosis
A
- Autosomal dominant
- Mental retardation, seizures in infancy
- Angiofibromas on face, shagreen patches/ash leaf spots (Wood lamp), nail fibromas
- Neuroectoderm abnormalities —> “tubers” in cerebral CTX
- Subependymal giant cell astrocytomas (“candlestick drippings” in ventricles), angiomyolipoma of kidney, rhabdomyoma of heart
11
Q
Sturge-Weber syndrome
A
- Vascular malformation of face (trigeminal nerve distribution)
- Ipsilateral AV malformation in meninges
- Unilateral “port wine stain” on face
12
Q
Acute epidural hematoma
A
- Middle meningeal artery bleed creates blood-filled space b/w bone and dura
- Temporoparietal bone Fx
- May have period of lucidity before neuro degeneration
- Often fatal
13
Q
Subdural hematoma
A
- Bridging veins b/w brain and dural sinus bleed b/w dura and arachnoid membrane
- Slowly enlarging blood clot covers brain
- Sx may emerge over months: HA, contralateral weakness, seizures, etc.
14
Q
Atherosclerotic stroke
A
- Majority preceded by TIA
- Pale infarct (no reperfusion)
- Edema, loss of gray-white differentiation, myelin breakdown
- 3-10 day: liquefactive necrosis —> cystic change
- MCA: contralateral hemiparesis and sensory loss in face and upper extremity; expressive aphasia; visual field defect
- ACA: contralateral hemiparesis and sensory loss in lower extremity
- Vertebrobasilar arterial system: deafness, vertigo, ataxia, ipsilateral sensory loss in face, contralateral in trunk and limbs
15
Q
Embolic stroke
A
- Most emboli from L heart (mural thrombus, A fib)
- MCA
- Hemorrhagic infarct (reperfusion)
16
Q
Intracerebral hemorrhage
A
- HTN
- Abrupt Sx onset
- Lenticulostriate branches develop Charcot-Bouchard microaneurysms that rupture
- Basal ganglia/thalamus, pons, cerebellum
- Slit hemorrhages (resorbed blood from small vessels)
- Lobar ICH: white matter hemorrhage suggestive of amyloid angiopathy, vascular malformation, coagulopathy, or bleeding from tumor
17
Q
Subarachnoid hemorrhage
A
- Berry aneurysm or AV malformation
- Thunderclap headache w/ nuchal rigidity
- Risk factors: epithelial stressors
- Communicating branches, most often anterior + ACA
- Blood covers surface of brain
- Xanthochromia (bilirubin makes CSF yellow)
- In survivors, rebleeding is frequent
18
Q
Lacunar infarct
A
- Small cystic infarcts of parenchymal arteries or arterioles
- Risk factors: HTN, atherosclerosis
19
Q
Meningitis
A
- Inflammation of pia mater
- Usu. hematogenous spread
- Seizures, focal neuro deficits, CN palsies, hearing loss, hydrocephalus
20
Q
Multiple sclerosis
A
- Females 20-40 y/o
- HLA-DR2 (or others) and microbial triggers
- Type 2 and 4 hypersensitivity: TH1, TH17, CD8 T cells, and Abs vs myelin sheath and oligodendrocytes
- Episodic course
- Often begins with visual complains
- Paresthesias; loss of pain, temp, vibratory sense
- Spasticity; increased DTRs; muscle weakness; urinary incontinence
- Optic neuritis (blurry/lost vision); cerebellar ataxia; “drunken” speech; intention tremor; nystagmus; ophthalmoplegia
- Increased CSF WBCs, protein
21
Q
Arbovirus
A
- Encephalitis
- Mosquitos all over US
22
Q
Coxsackievirus
A
- Meningitis
- Enterovirus
23
Q
CMV
A
- Encephalitis
- Neonates (vertical transmission) or AIDS patients
- Eosinophilic inclusions
24
Q
HSV1
A
- Meningitis and encephalitis
- Hemorrhagic temporal lobe necrosis
25
Q
HIV
A
- Encephalitis
- Slowness of thought and bradykinesis
- Microglial cells fuse to form multinucleated cells
26
Q
Lymphocytic choriomeningitis
A
- Meningitis and encephalitis
- Mouse transmission
27
Q
Poliovirus
A
- Encephalitis and spinal cord inflammation
- Destroys upper and lower motor neurons
- Muscle paralysis
28
Q
Rabies virus
A
- ACh receptor; moves to CNS, then saliva
- Incubation period 10-90 days
- Prodrome: fever, paresthesias at wound site
- Hydrophobia
- Encephalitis: seizures, coma, death
- Eosinophilic inclusions called Negri bodies
29
Q
Progressive multifocal leukoencephalopathy
A
- Slow encephalitis
- AIDS patients
- Papovavirus (JC virus)
- Scattered demyelination foci
- “Ground-glass” inclusions in oligodendrocytes
30
Q
Subacute sclerosing panencephalitis
A
- Slow, fatal encephalitis
- Rubeola (measles) virus
- Inclusions in neurons and oligodendrocytes
31
Q
Bacteria that cause neonatal meningitis
A
- Group B strep (Gram+ coccus)
- E. coli (Gram- rod)
- Listeria monocytogenes (Gram+ rod with tumbling motility; cheese and hot dogs)
32
Q
Bacteria that cause meningitis
A
- Neisseria meningitidis (Gram- diplococcus); children; may show petechial rash
- Strep pneumoniae (Gram+ diplococcus); high incidence w/ basilar skull Fx
- Mycobacterium tuberculosis (complication of primary tuberculosis); involves base of brain; tuberculomas w/ caseous necrosis; may also cause Pott disease (in spine)
- T. pallidum (Gram- spirochete); multiple small infarcts; may also cause tabes dorsalis (loss of joint position sense and fine touch); late recurrence may cause dementia with “wind-blown appearance” of cortical neurons and “rod cells” (iron-encrusted microglia)
33
Q
Fungi that cause meningitis
A
- Cryptococcus neoformans (immunocompromised; budding yeasts visible w/ India ink)
- Mucor species (frontal lobe abscess; diabetic ketoacidosis)
- Coccidiodes immitis (Southwest US; refractile endosporulating spherule)
34
Q
Parasites that cause CNS infections
A
- Naegleria fowleri (amoeba from freshwater lakes; frontal lobes)
- Trypanosoma brucei (hemoflagellate from tsetse fly; Winterbottom sign [post cerv lymph]; somnolence, cyclical fever)
- Taenia solium (helminth; pigs; eggs invade brain)
- Toxoplasma gondii (sporozoan; AIDS pts; ring-enhancing lesions on CT; congenital —> basal ganglia calcification)
- Acanthamoeba: granulomatous encephalitis; usu. fatal
- P. falciparum: diffuse swelling, microinfarcts w/ gliosis (Dürck granulomata) or many small hemorrhages
35
Q
Central pontine myelinolysis
A
- Alcoholics w/ hyponatremia
- Rapid salt correction CAUSES demyelination in basilar pons
36
Q
Adrenoleukodystrophy
A
- Boys 3-10 yrs old, progresses to coma
- XLR
- Deficiency in beta-oxidation of FAs
- Cortex-sparing loss of brain myelin, adrenal insufficiency
37
Q
Krabbe disease
A
- Autosomal recessive lysosomal storage disease
- Deficiency in galactocerebroside beta-galactocerebroside; accumulation of galactocerebroside
- Small brain w/ widespread myelin loss
- Large, multinucleated, histiocytic globoid cells
- Death w/in 1-2 yrs
38
Q
Friedreich ataxia
A
- Autosomal recessive, Sx appear before age 25
- Frataxin deficiency (iron transport into mitochondria)
- Degeneration of dorsal root ganglia, posterior columns, sensory peripheral neurons
- Hypertrophic cardiomyopathy
- Gait ataxia, DTR loss, vibratory/proprioception loss, BLE weakness
39
Q
Astrocytoma
A
- Diffuse tumors
- Adults: frontal lobe, children: cerebellum
- Diffuse pontine astrocytoma: lethal pontine tumor in young children
- Pilocytic astrocytoma: does not infiltrate; well-circumscribed; Rosenthal fibers
- Pleomorphic xanthoastrocytoma: Hx of seizures; BRAF mutation; very pleomorphic but low mitotic activity
- Subependymal giant cell astrocytoma: associated w/ tuberous sclerosis; low-grade tumor in lateral ventricle causing hydrocephalus
40
Q
Glioblastoma
A
- Astrocytoma
- Hemorrhagic tumor
- Ring-enhancing areas of necrosis and cystic degradation
- Commonly cross corpus callosum (“butterfly” glioblastoma)
41
Q
Meningioma
A
- Benign tumor of meningothelial cell of arachnoid membrane
- Female predominance (progesterone receptors)
- Parasagittal MC location; may appear in dural venous sinuses
- Risk factors: NF2, Hx of radiation
- Well-circumscribed, firm, tan tumor that may infiltrate bone
- Swirling mass of meningothelial cells encompass psammoma (calcified) bodies
- Common cause of new-onset focal seizures
42
Q
Ependymoma
A
- Benign tumor of ependymal cells, usually in children and young adults
- Children: 4th ventricle, may produce hydrocephalus
- Adults: cauda equina
- Well-circumscribed with (pseudo-)rosettes
- Myxopapillary ependymoma: low SC of adults
- Subependymoma: adults, usu. asymptomatic but may block foramen of Monro or 4th ventricle outlet
43
Q
Medulloblastoma
A
- Malignant small cell tumor of children; occasionally adults 20-45 y/o
- Cerebellum; often seeds neuraxis and invades 4th ventricle
- Desmoplastic/nodular variants: common in adults or infants, resembles lymph nodes; SHH gene
- Anaplastic/large cell variants: Wnt gene
44
Q
Oligodendroglioma
A
- Benign tumor of oligodendrocytes
- Frontal lobe tumor that frequently calcifies
- Highly infiltrative but responsive to therapy
- Chromosome 1:19 translocation
- “Fried egg” appearance of cells, blood vessels in “chicken wire” pattern
- Cells cluster around neuron cell bodies or blood vessels
45
Q
CNS lymphoma
A
- Majority are metastatic high-grade B-cell non-Hodgkin lymphomas
- Often AIDS and/or EBV-associated
46
Q
Schwannoma
A
- Benign tumor of Schwann cells
- Acoustic neuroma: CN 8; cerebellopontine angle; NF2 association; may impinge on CN 5
47
Q
Metachromatic leukodystrophy
A
- Accumulation of cerebroside in white matter and peripheral nerves
- Rusty-brown coloring with violet or blue stains
- Disease of infancy, lethal w/in several years
48
Q
Tay-Sachs disease
A
- Hexosaminidase A deficiency w/ accumulation of ganglioside
- Cherry-red spot in macula, lipid droplets distent neurons
- Delayed motor development by 6 mos., death w/in 2 yrs
49
Q
Subacute combined degeneration
A
- B12 deficiency (pernicious anemia)
- Degeneration of thoracic posterior spinal cord
- Burning in soles of feet, other paresthesias
- Limb weakness, defective postural sensibility, incoordination
50
Q
Huntington’s disease
A
- Involuntary movements, deteriorating cognitive fxn, emotional disturbances
- Frontal CTX and caudate/putamen atrophy, lateral ventricle enlargement
51
Q
Holoprosencephaly
A
- Telencephalon (CTX and basal ganglia) fails to divide
- Single large ventricle
- Mildest form: arrhinencephaly (failure of olfactory nerves)
52
Q
Choroid plexus papilloma
A
- Children: lateral ventricle, adults: 4th ventricle
- May disseminate via CSF
53
Q
Atypical teratoid/rhabdoid tumor (ATRT)
A
- Malignant tumor of early childhood
- Differentiation along multiple different cell lines
- Often posterior fossa (cerebellum, brainstem)
- Inactivation of INI-1
54
Q
Craniopharyngioma
A
- Often children
- Sella turcica region, causing endocrine and visual disturbances
- Heterogeneous tumor
- Adamantinomatous type: sheets of squamous epithelium with palisading, “stellate reticulum,” “wet keratin,” possible Rosenthal fibers
- Papillary: exclusively squamous epithelium
55
Q
Germinoma
A
- Often involve pineal gland
- Large malignant cells + small reactive lymphocytes, may have granulomatous response
56
Q
Hemangioblastoma
A
- Mainly cerebellum, can be seen in SC and brainstem
- Risk factors: von Hippel-Lindau disease
- Cystic w/ enhancing mural nodules
