Neuropath Flashcards
Dementia
Decrease in cognitive ability, memory, or function with intact consciousness.
Alzheimer's Pick's (frontotemporal dementia) Lewbody dementia Creutzfeldz-Jakob (CJD) Other causes
Dementia: alzheimers
Common in elderly, increased in Down
Familial form (10%) with altered protein (chromosome)
- Early onset: APP(21), presenilin-1 (14), presenilin 2 (1)
- late onset: ApoE4 (9)
- ApoE2 (19) protective
Finding: widespread cortical atrophy, low ACh
Senile plaques: extracellular beta-amyloid core, may cause amyloid angiopathy -> intracranial hemorrahge.
Abeta synthesized by cleaving amyloid precursor protein.
+ neurofibrillary tangle: intracellular abn phosphorylated tau protein = insoluble cytoskeletal elements; tangles correlates with degree of dementia
Dementia: pick’s disease
Frontotemporal dementia: dementia, aphasia, parkinson aspects; change in personality
Spares parietal lobe and posterior 2/3 of superior temporal gyrus.
Picks bodies: spherical tau protein aggregates
Frontotemporal atrophy
Dementia: Lewy body dementia
Parkinsonism with dementia and hallucinations
alpha synuclein defects
Dementia: Creutzfeldtz Jakob
Rapidly progressive (wks to months) dementia with myoclonus (startle myoclonus)
Spongiform cortex:
Prios (PrPc -> PrPsc sheet, beta pleated sheet resistant to protease)
Dementia: other causes
Multi-infarct: 2nd most common cause of dementia in elderly, syphillis, vitamin B1, B3, B12 deficiency. Wilson’s disease and normal pressure hydrocephalus.
Multiple sclerosis
Demyelination of CNS (brain and spinal cord)
Optic neuritis (sudden loss of vision), MLF syndrome (internuclear ophthalmoplegia), hemiparesis, hemisensory symptoms, or bladder/bowel incontinence.
Relapsing and remitting course.
Most often affect women in their 20s and 30s; more common in whites.
Finding: elevated IgG in CSF, oligoclonal bands are diagnostic, MRI gold standard. Periventricular plagues (areas of oligodendrocyte loss and reactive gliosis) with destruction of axons
Treatment: IFN beta, immunosupp, natalizumab, symptomatic treatment for neurogenic bladder (cath, muscarnic antagonist), spasticity (baclofen, GABA agonist), pain (opioid)
Charcot’s triad:
Scanning speech,
Intention tremor, incontinence, internuclear ophthalmoplegia
Nystagmus
Acute inflammatory demyelinating polyradiculopathy
Most common variant of Guillan-Barre
Autoimmune condition that destroys Schwann cells
Inflam and demyelination of peripheral nerves and motor fibers. Results in symmetric ascending muscle weakness/paralysis BEGINNING in lower extremities.
Facial paralysis in 50% of cases
Associated with campy or CMV
Autonomic function may be severely affected (cardiac, HTN, or hypotension)
Almost all pts survive, majority recover completely after weeks to months.
Finding: CSF protein with normal cell count, increased protein -> papilledema
Treatment: respiratory support critical until recovery, plasmaphresis, IV immune globulins.
Demyelinating: progressive multifocal leukoencephalopathy (PML)
Demyelination pf CNS due to destruction of oligodendrocytes
Associated with JC virus, seen in 2-4% (reactivation)
Rapidly progressive and usually fatal
Demyelinating: acute disseminated (postinfectious) encephalomyelitis
Multifocal perivenular inflam and demyelination after infection, commonly measles or VZV, or certain vaccinations (rabies, smallpox)
Demyelinating: metachromatic leukodystrophy
AR lysosomal storage disease, most due to arylsulfatase A deficiency.
Build up of sulfatide leads to impaired production of myelin sheath
Demyelinating: Charcot-Marie-Tooth disease
Hereditary motor and sensory neuropathy (HMSN)
Group of progressive hereditary nerve disorder related to the defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath.
Demyelinating: Krabbe’s disease
AR lysosomal storage disease, most due to deficiency of galactocerebrosidase
Build up of galactocerebroside destroys myelin sheath.
Seizures
Characterized synchronized, high frequency neuronal firing.
Partial (focal) seizure
Affect 1 area of the brain
Most commonly in medial temporal lobe
Often preceded by seizure aura; can secondarily generalize.
Type:
1) simple: (conscious intact) motor, sensory, autonomic, psychic
2) complex partial (impaired conscious)
Epliepsy: disorder of recurrent seizures (not febrile seziure)
Statis epilepticus: continous seizure for >30 min or recurrent seizures without regaining consciousness between seizures for >30 min. Medical emergency.
Causes:
Children: congenital, infection (febrile), trauma, genetic, metabolic
Adults: tumor, trauma, stroke, infection
Elderly: stroke, tumor, trauma, metabolic, infection.
