Pathology - neuro Flashcards
Senile amyloid plaques, amyloid angiopathy
Intracellular neurofibrillary tangles
decr. ACh
ApoE4
Alzheimer’s
incr. risk with Down syndrome, APP
Look for B-amyloid (extracellular) and tau proteins (intracellular), increased intracellular NF tangles –> incr. degree of dementia
decr. ACh in basal nucleus of Meynert
first radiological sign: hippocampal atrophy
Pick bodies (spherical tau protein aggregates) Change in personality
Frontotemporal dementia
Look for parietal lobe sparing
Some parkinsonian aspects as well
Dementia + visual hallucinations + parkinsonism
Lewy body dementia
alpha-synuclein defect
Protein structure in CJD
Prions form beta-pleated sheet resistant to proteases
MS findings
incr IgG in CSF (oligoclonal bands)
MRI is gold standard - periventricular plaques (loss of oligos and reactive gliosis) with destruction of axons
Multiple white matter lesions separated in space and time
Autoimmune condition that destroys Schwann cells –> ascending weakness
Guillain-Barre syndrome
Inflammation and demyelination of peripheral nerves and motor fibers (molecular mimicry s/p infection) –> symmetric, ascending weakness
Look for incr. CSF protein w/ normal cells (albuminocytologic dissociation) that may be causing papilledema
Autosomal dominant, assoc. with scoliosis and foot deformities
Charcot-Marie-Tooth
defective production of proteins involved in the structure and function of peripheral nerves or the myelin heath
Excess buildup of very long chain fatty acids in the nervous system, adrenal gland, testes
Adrenoleukodystrophy
X-linked, seen in males, disruption of metabolism
Progressive, leads to coma/death or adrenal crisis
Origin of partial seizures
Medial temporal lobe
preceded by aura, can secondarily generalize
simple = consciousness intact, complex = loss of consciousness
headaches, bilateral, steady pain, no aura
Tension
Tx: analgesics, NSAIDs
Mechanism of migraine headaches
Irritation of CN V, meninges of blood vessels
release of substance P, calcitonin gene-related peptide, vasoactive peptides
POUND: pulsatile, one-day, unilateral, nausea, disabling
Peripheral vs. central vertigo
Peripheral: more common, inner ear etiology, delayed horizontal nystagmus
Central: brain stem/cerebellar lesion, diplopia/dysmetria/skew deviation, immediate nystagmus in any direction, assoc. w/ focal neuro findings
Port-wine stain on face
ipsilateral leptomeningal angioma
intellectual disability
early onset glaucoma
Sturge-Weber syndrome (affect small blood vessels/capillaries)
GNAQ gene activation - developmental anomaly of neural crest derivatives
STURGE: stain, tram track calcifications, unilateral, retardation, glaucoma, GNAQ gene, epilepsy
Neuro complications of tuberous sclerosis
Mental retardation, seizures, incr. incidence of subependymal astrocytomas and ungual fibromas
Hemangioblastomas in retina, brain stem, cerebellum, spine
Cavernous hemangiomas everywhere
von Hippel Landau disease
bilateral renal cell carcinomas + pheochromocytomas
Brain tumor that…
… crosses corpus callosum (butterfly glioma)
… stains for GFAP
… pseudopalisading pleomorphic tumor cells
GBM (adults)
1 yr survival
Brain tumor that…
… extra-axial, found near surface of brain
… arise from arachnoid villi
… spindle cells in whorl pattern + psmammoma bodies
Meningioma (adults)
Often asymptomatic, may present with seizures or focal signs
Brain tumor that…
… cerebellar, assoc. w/ vHL syndrome
… can produce EPO, causing polycythemia
… closely arranged capillaries
Hemangioblastoma (adults)
Brain tumor that…
… stains for S-100
… cerebellopontine angle
Schwannoma (adults)
bilateral in NF2
Brain tumor that…
… rare, slow growing
… chicken-wire pattern, fried egg cells
Oligodendroglioma (adults)
Brain tumor that…
… well circumscribed in posterior fossa
… grossly, cystic and solid components
… stains for GFAP
Pilocytic astrocytoma (children)
benign, good prognosis
Brain tumor that…
… highly malignant cerebellar tumor, commonly in the vermis
… neuroectodermal
… can compress 4th ventricle
Medulloblastoma (children)
Brain tumor that…
… found in 4th ventricle
… perivascular rosettes
… poor prognosis
Ependymoma (children)
perivascular rosettes
Cingulate herniation under falx cerebri
Compression of anterior cerebral artery
Sensory and motor loss in the lower extremities
Downward transtentorial herniation
Caudal displacement of brain stem, rupture of paramedian basilar artery branches, Duret hemorrhages
usually fatal
Uncal herniation
Medial temporal lobe
Compresses ipsilateral CNIII (blown pupil), ipsilateral PCA (contralateral vision loss), ipsilateral paresis
Cerebellar tonsil herniation
Coma and death if there is compression of brain stem
Lacunar infarcts
due to hypertensive changes in the arterioles
Look for arteriolar sclerosis
ischemic changes
Charcot-Bouchard pseudoaneurysms
less than 1mm in diameter
long-standing hypertension
hemorrhagic changes
Lesions found in Wernicke encephalopathy
Foci of hemorrhage and necrosis in mamillary bodies
Complications of subarachnoid hemorrhage
secondary arterial vasospasm –> cerebral ischemia
due to impaired brain autoregulation
Autosomal recessive, trinucleotide repeat, impairment in mitochondrial functioning, degeneration of spinal cord tracts
Friedrich ataxia
gait ataxia, scoliosis, foot abnormalities, hypertrophic cardiomyopathy
impaired upward gaze + hormone secretion (bhCG) + obstructive hydrocephalus
Pineal gland tumor
Most commonly, germinoma
Sensory ataxia + lancinating pains + urinary incontinence + Argyll Robertson pupil
Tabes dorsalis caused by syphillis
Dystrophies genetics
Duchenne - loss of protein that normally helps anchor muscle fibers (connects actin cytoskeleton to dystroglycan, which connect to ECM)
Myotonic - abnormal expression of myotonin protein kinase, myotonia, cataracts, testicular atrophy,
Liquefactive necrosis
Cystic cavity surrounded by gliosis
Release of lysosomal enzymes from ischemic neurons results in degradation of local tissue
phagocytes clean up, then area is surrounded by astrocytes to form a glial scar
Alcohol withdrawal
Tremor then autonomic dysfunction then seizures then delirium tremens (hallucinations, confusion, severe symp discharge)
Spinal cord syndromes
Tabes dorsalis vs. B12 deficiency vs. ASA syndrome
Tabes dorsalis - dorsal columns, dorsal roots (loss of position/vibration)
B12 deficiency - dorsal columns, lateral corticospinal tracts, axonal degeneration of peripheral nerves (loss of position/vibration, UMN signs, numbness/parasthesia)
ASA - complete loss of strength below the level of injury with loss of pain and temp sensation
Global cerebral ischemia
Affects hippocampus first!
Also Purkinje cells of cerebellum
Complications of meningitis
Communicating hydrocephalus - decr. function of the arachnoid granulations
Association with cerebral amyloid angiopathy
Recurrent hemorrhagic strokes
