Neuro patho 0426 Flashcards
dementia
decrease in cognitive ability, memory, or function with intact consciousness.
loss of neurons in GRAY matter.
Alzheimer disease
widespread cortical atrophy.
decreased ACh.
senile plaques and neurofibrillary tangles.
most common cause of dementia in elderly
Alzheimer disease
Alzheimer disease + Down syndrome
Down pts have increased risk of developing AD - APP gene is on chromo 21.
genes in Alzheimer disease
familial form = 10%. most cases are sporadic.
early onset: amyloid precursor protein (APP) on chromo 21. presenilin-1 on 14. presenilin-2 on 1.
late onset: ApoE4 on 19.
protective gene in Alzheimer disease
ApoE2 on chromo 19
senile plaques of Alzheimer disease
extracellular BETA-AMYLOID core.
Abeta amyloid synthesized by cleaving APP.
may cause amyloid angiopathy leading to intracranial hemorrhage.
neurofibrillary tangles in Alzheimer disease
intracellular, abnormally phosphorylated TAU PROTEIN (insoluble cytoskeletal elements).
tangles correlate with degree of dementia.
Pick’s disease
frontotemporal dementia. frontotemporal ATROPHY.
aphasia, parkinsonian aspects, change in personality.
spares parietal lobe and posterior 2/3 of superior temporal gyrus.
Pick bodies.
Pick bodies
intracellular aggregated TAU PROTEIN
Lewy body dementia
parkinsonism with early dementia and hallucinations.
cortical Lewy bodies due to ALPHA-SYNUCLEIN defect.
Creutzfeld-Jacob disease
rapidly progressive dementia with MYOCLONUS. weeks to months.
spongiform cortex (vacuoles).
prions with beta-pleated sheet conformation -resistant to proteases, build up in neurons (PrPc to PrPsc)
other causes of dementia
multifocal infarct (vascular) - #2 cause in elderly.
syphilis HIV vit B12 deficiency Wilson's dz normal pressure hydrocephalus
multiple sclerosis
autoimmune inflamm and demyelination of CNS. destruction of axons.
affects white women in 20s, 30s.
MS presentation
RELAPSING/REMITTING COURSE: optic neuritis (sudden loss of vision) MLF syndrome hemiparesis hemisensory sx bladder/bowel incontinence
Charcot’s classic triad
- Scanning speech
- Intention tremor, incontinence
- Nystamus (internuclear ophthalmoplegia)
“MS is a SIN”
MS dx findings
increased protein (IgG) in CSF. OLIGOCLONAL BANDS.
gold standard: MRI - periventricular plaques (areas of oligodendrocyte loss and reactive gliosis).
lipid-laden macrophages contain myelin breakdown products.
MS tx
beta interferon
immunosuppression
natalizumab
symptomatic tx
for neurogenic bladder: cath, musc antagonists
for spasticity: baclofen, GABA agonist
for pain: opioids
Guillain barre syndrome
aka acute inflammatory demyelinating polyradiculopathy.
inflamm and segmental demyelination of peripheral nn. and motor fibers of ventral roots. Schwann cell destruction.
endoneural inflamm infiltrate.
Guillain barre syndrome - clinical
SYMMETRIC ascending muscle weakness, beginning in distal LEs.
absent DTR.
Bell’s palsy, facial paralysis.
autonomic dysfunction (cardiac irregularities, HTN or hypotension)
Guillain barre syndrome - cause
assoc. with infxs - AUTOIMMUNE attack of peripheral myelin due to MOLECULAR MIMICRY.
campylobacter jejuni herpesvirus inoculations/immunizations allergic rxn stress
Guillain barre syndrome - prognosis
almost all pts survive.
most recover completely after wks to months.
Guillain barre syndrome - dx
increased CSF protein with normal cell count (ALBUMINOCYTOLOGIC DISSOCIATION).
increased protein can lead to papilledema.
