Pathoma Flashcards
1
Q
neural tube defects
A
- associated with low folate levels prior to conception
- elevated AFP in amniotic fluid and maternal blood
- anencephaly: absence of skill and brain (cranial end disruption)
- spin bifida: failure of posterior vertebral arch to close
- occulta: dimple/patch of hair overlying defect
- meningocele: protrusion of meninges
- meningomyelocele: protrustion of meninges and spinal cord
2
Q
cerebral aqueduct stenosis
A
- congenital stenosis of channel that drains CSF from 3rd→ 4th ventricles
- MCC of hydrocephalus in newborns
- presents with enlarging head circumference due to dilation of ventricles; cranial suture lines are not fused
3
Q
dandy-walker malformation
A
- congenital failure of cerebellar vermis to develop
- presents as massively dilated 4th ventricle with an absent cerebellum
- often accompanied by hydrocephalus
4
Q
arnold-chiari malformation
A
- type I: no symptoms; post. fossa forms too shallow for cerebellum
- associated with syringomyelia
-
type II: congenital downward displacement of cerebellar vermis and tonsils through foramen magnum→ obstruction of CSF flow→ hydrocephalus
- associated with meningomyelocele
5
Q
syringomyelia
A
- cystic degeneration of spinal cord
- arises with trauma or in association with arnold-chiari type I
- C8-T1 location; ant. white commisure of spinothalamic tract with sparing of dorsal column
- cape like distribution: loss of pain and temperature, sparing of fine touch and proprioception in upper extremeties
- syrinx expansion→ LMN of ant. horn (muscle atrophy/weakness) and lateral horn of hypothalamospinal tract (horner syndrome)
6
Q
poliomyelitis
A
- damage to ant. motor horn due to poliovirus infection
- LMN signs (flaccid paralysis with muscle atrophy, fascicuations, weakness and decreased tone, impaired relfexes)
7
Q
werdnig-hoffman disease (SMN-1)
A
- AR; degeneration of ant. motor horn
- presents as floppy baby; death in a few years
8
Q
amyotrophic lateral sclerosis (ALS)
A
- degenerative disorder of UMN and LMN of corticospinal tract
- ant. motor horn: LMN signs
- lateral corticospinal tract: UMN signs
- atrophy and weakness of hands is early sign
- lack of sensory impairment (no loss of pain/temp distinguishes from syringomyelia)
- most cases are sporadic; average age is 60yrs
- zinc-copper SOD1 present in some cases (ROS injury neurons)
9
Q
friedreich ataxia
A
- AR; degeneration of cerebellum and spinal cord (post. columns, distal CST, spinocerebellar)
- ataxia
- loss of vibratory sense and proprioception, muscle weakness in lower extremities, loss of deep tendon reflexes
- due to expansion of trinucleotide repeat in frataxin gene (essential for mitochondria Fe regulation; loss results in Fe buildup→ ROS)
- associated with hypertrophic cardiomyopathy
10
Q
meningitis
A
- MC due to infectious agent
- neonates: group B strep, e. coli, listeria
- kids/teens: n. meningitidis, coxsackie
- nonvacc. infants: flu
- adults/elderly: strep pneumo
- immunocompromised: fungi
- headache, nuchal rigidity, fever; photophobia, vomiting, AMS
- diagnosis by LP (between L4&5 at iliac crest; cross skin ligaments, epidural space, dura, and arachnoid NOT pia)
- bacterial: neutrophila with low glucose
- viral: lymphocytes and normal glucose
- fungal: lymphocytes with low glucose
- complications due to bacteria (death due to herniation, sequlae related to fibrosis)
11
Q
global cerebral ischemia
A
- etiologies
- low perfusion (atherosclerosis)
- acute decrease in blood flow (cardiogenic sock)
- chronic hypoxia (anemia)
- repeated episodes of hypoglycemia (insulinoma)
- mild→ transient confusion with prompt recovery
- moderate→ infarcts in watershed areas and damage to vulnerable regions (cerebral cortex 3, 5, 6; hippocampus; purkinje of cerebellum)
- severe→ diffuse necrosis, survival in vegetative state
12
Q
ischemic stroke
A
- regional ischemia→ focal neurologic deficits lasting >24 hrs (<24hrs= transient ischemic attack)
- subtypes: thrombotic, embolic, lacunar
- results in liquefactive necrosis
- red neurons (dead) are early microscopic findings
- necrosis (24 hrs) infiltration by neutrophils (day 1-3), and microglial cells (day 4-7), and gliosis (weeks 2-3)
- fluid filled cystic space surrounded by gliosis
13
Q
thrombotic stroke
A
- due to rupture of atherosclerotic plaque
- results in pale infarct at periphery of cortex
14
Q
embolic stroke
A
- due to thromboemboli (MC source is L heart, e.g., due to afib)
- usually involves middle cerebral artery
- results in hemorrhagic infarct at periphery of cortex
15
Q
lacunar stroke
A
- occur secondary to hyaline arteriolosclerosis (complication of HTN or diabetes)
- MC involves lenticulostriate vessels→ small cystic areas of infarction
- internal capsule: pure motor
- thalamic involvement: pure sensory
16
Q
intracerebral hemorrhage
A
- bleeding into brain parenchyma
- classically due to rupture of charcot-bouchard microaneurysms of lenticulostriate
- complication of HTN
- basal ganglia is MC site
- presents as severe headache, N/V, eventual coma
17
Q
subarachnoid hemorrhage
A
- bleeding into subarachnoid space
- sudden headache (worst ever) with nuchal rigidity
- LP: xanthochromia (yellow due to BR)
- MC due to ruptured berry aneurysm (saccular outpouchings that lack media; occur at branch points of ant. communicating artery)
- associated with Marfan’s and AD PCKD
18
Q
epidural hematoma
A
- blood between dura and skull
- classically due to fracture of temporal bone with rupture of middle meningeal artery→ high pressure bleed→ medical emergency (burr hold to evacuate)
- herniation is lethal complication
19
Q
subdural hematoma
A
- collection of blood underneath dura
- due to tearing of bridging veins, usually due to trauma
- increased rate in eldery/alcoholics due to atrophy (brain shrinks and veins are stretched)
20
Q
brain herniation
A
- displacement of brain tissue due to mass effect or increased ICP
- tonsillar herniation: cerebellar tonsils→ foramen magnum; brain stem compression leads to cardiopulmonay arrest
- subfalcine herniation: cingulate gyrus under flax cerebri; ant. cerebral artery leads to infarction
-
uncal herniation: temporal lobe uncus under tentorium cerebelli
- compression of CN II→ eye is down and out, dilated pupil
- compression of post. cerebral artery: infarction of occipetal lobe→ contralateral homonymous hemianopsia
- rupture of paramedian artery→ brainstem hemorrhage
21
Q
leukodystrophies
A
- mutations in enzymes needed for production/maintenance of myelin
- metachromatic LKD: deficiency of arylsulfatase (can’t degrade myeline); AR
- krabbe disease: deficiency of galactocerebrosidase; AR
- adrenoleukodystrophy: impaired addition of coA to long chain fatty acids; x-linked
22
Q
multiple sclerosis
A
- autoimmune destruction of CNS myeline and oligodendrocytes
- MC CNS disease of young agults; MC in women; MC in regions away from equator
- associated with HLA-DR2
- presents with neurologic deficits with periods of remission: blurred vision, scanning speech, internuclear ophthalmoplegia
- MRI: plaques (areas of white matter demyelination)
- LP: increased lymphocytes, Ig with oligoclonal IgG bands, myelin basic protein
- high dose steroids for acute treatment; IFNß slows progression
23
Q
subacute sclerosing panencephalitis
A
- slowly progressing persistent infection of brain by measles→ debilitating encephalitis→ death
- viral inclusions within neurons and oligodendrocytes
24
Q
progressive multifocal leukoencephalopathy
A
- JC virus infection of oligodendrocytes
- immunosuppression leads to reactivation of latent virus
- rapidly progressive neurologic signs→ death
25
Q
central pontine myelinosis
A
- focal demyelination of pons due to rapid IV correction of hyponatremia
- occurs in severely malnourished patients (alcoholics, patients with liver disease)
- presents as acute bilateral paralysis (locked-in syndrome, can’t move anything except eyes)
26
Q
alzheimer’s disease
A
- degenerative disease of cortex; MCC of dementia
- slow-onset memory loss (short term then long term) and progressive disorientation
- early onset: familial cases (presenilin 1 and 2 mutations) and down syndrome
- 95% are sporadic and seen in elderly
- e4 allele of APOE associated with increased risk, e2 associated with decreased risk
- cerebral atrophy with narrowing gyri, widening sulci, dilation of ventricles
- neuritic plaques: extracellular core of AB amyloid with entangled neuritic processes; congo red stain
- neurofibrillary tangles: intracellular aggregates of fibers of hyperphosphorylated tau
27
Q
vascular dementia
A
- multifocal infarction and injury due to HTN, atherosclerosis, or vasculitis
- 2nd MCC of dementia
28
Q
pick disease
A
- degenerative disease of frontal and temporal cortex (occipetal and parietal sparing)
- characterized by round tau aggregates (pick bodies) in cortex
- behavioral and language symptoms→ dementia
29
Q
parkinson disease
A
- degenerative loss of dopaminergic neurons in substantia nigra of basal ganglia (specifically pars compacta)
- nigrostriatal pathway normally initiates movement
- loss of pigmented neurons in substantia nigra
- lewy bodies: eosinophilic inclusions of a-synuclein
- TRAP: Tremor, Rigidity, Akinesia, Postural instability/shuffling gait
- dementia later
- early onset is suggestive of lewy body dementia (cortical lewy bodies)
30
Q
huntington’s disease
A
-
AD degeneration of GABAergic (inhibitory NT) in caudate nucleus of basal ganglia
- anticipating (expansion of repeats during spermatogenesis
- presents with chorea ~40→dementia and depression
31
Q
normal pressure hydrocephalus
A
- increased CSF→ resulting in dilated ventricles→ stretch of corona radiata→ dementia
- wet, wobbly, wacky
- LP improves syptoms; treat with ventriculoperitoneal shunting
32
Q
spongiform encephalopathy
A
- degenerative disease due to prior protein
- normal a-helical PrPc; disease with conversion to ßpleated PrPsc
- can’t degrade→ damages neurons and glial cells; creates more PrPsc from PrPc
- CJD: MC; usually sporadic in elderly but can arise due to exposure to prion-infected human tissue; periodic sharp waves on EEG, death <1 year
- vCJD: related to exposure to “mad cow”; younger patients
33
Q
MC CNS tumors in adults
A
- glioblastoma multiforme
- meningioma
- schwannoma
34
Q
MC CNS tumors in children
A
- pilocytic astrocytoma
- ependymoma
- medulloblastoma
35
Q
glioblastoma multiforme
A
- high grade tumor of astrocytes (GFAP+)
- MC primary malignant CNS tumor of adults
- arises in cerebral hemisphere, usually crosses corpus collosum (butterfly lesion)
- regions of necrosis surrounded by pseudopalisading tumor cells
- ring enhancing lesion around area of necrosis
36
Q
meningioma
A
- tumor of arachnoid cells; ER+ (more common in women)
- MC benign CNS tumor of adults
- round mass attached to dura; whorled pattern; psamomma bodies
- tumor compresses but does not invade cortex→ seizures
37
Q
schwannoma
A
- benign tumor of schwann cells (S-100+)
- commonly involves CN VIII at cerebellopontine angle (loss of hearing and tinnitus)
- bilateral tumors in NF2
38
Q
oligodendroma
A
- malignant tumor of oligodendrocytes
- calcified tumor in white matter
- biopsy: fried egg appearance of cells, chickenwire capillaries
39
Q
pilocytic astrocytoma
A
- benign tumor of astrocytes (GFAP+)
- MC CNS tumor of children
- cystic lesion with mural nodule, usually in cerebellum
- enhancing lesion (NOT ring enhancing)
- biopsy: rosenthal fibers; eosinophilic granular bodies
40
Q
medulloblastoma
A
- malignant tumor, usually in kids
- derived from granular cells of cerebellum (neuroectoderm)
- biopsy: small round blue cells
- grows rapidly, spread via CSF→ drop metastasis to cauda equina
41
Q
ependymoma
A
- malignant tumor of ependymal cells (line ventricles)
- MC arises in kids in 4th ventricle
- may block CSF flow→ hydocephalus
- biopsy: perivascular pseudorosettes
42
Q
craniopharyngioma
A
- benign tumor of epithelial remants of Rathke’s pouch
- supratentorial mass in child, may compress optic chiasm→ bitemporal hemianopsia
- calcifications (derived from floor of mouth/tooth-like tissue)
