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Vascular DementiaUrinary dysfunction, gait disturbance / can have Parkinsonian motor features of CVA Periventricular white-matter lesions are non-specific (can occur in normal aging) Vitamin Deficiencies (causing dementia) Thiamine (see other) Wernicke’s horizontal nystagmus, opthalmoplegia, cerebellar ataxia, encephalopathy (psychoses), orthostatic hypotension Treatment: IV thiamine (with glucose otherwise can cause metabolic neuronal death) Korsakoff’s confabulation, confusion, memory loss (irreversible) Vitamin B12 (see other) subacute combined degeneration (ascending first, then descending track demyelination) Folate (see other) deficiency early in gestation causes neural tube defects Niacin (see other) dermatitis, diarrhea, dementia - degeneration of cortical and BG neurons (rare) Metabolic Disturbances Hypoglycemia - loss of pyramidal hippocampal neurons and cortical III-IV Hyperglycemia - hyperosmolar coma (type 2) or diabetic ketoacidosis (type 1) Hepatic Encephalopathy seizures, rigidity, asterixis (flapping tremor, hyperreflexia) Alzheimer’s 11 cells / edema / symptoms may resolve only 48-72 hrs after normalization of BUN (although symptoms may not correlate to BUN) / give lactulose +/- flagyl
Headache, nausea, confusion Mechanism: heme unable to let go of CO molecules, so heme cannot function properly to deliver O2 to body tissues Pathology: bilateral globus pallidus necrosis (medial) Diagnosis: venous or arterial carboxyhemoglobin levels Treatment: 100% FiO2 (hyperbaric if possible) to displace CO from heme Methanol bilateral putamen and claustrum necrosis (lateral) / retinal ganglion cell death Chronic ethanol ataxia, gait disturbance, nystagmus / degeneration of cerebellar vermis Rhabdomyolysis (see other) Serotonin syndrome (see other) Fetal alcohol syndrome Marchiafava-Bignami acute necrosis/dementia due to cheap red wine Radiation injury pattern of vasogenic and coagulative necrosis Lead cortical cell death (demyelination) in children peripheral neuropathy in adults (wrist and foot drop)
70% of dementia / 4 million in US / 15% familial (apoE e4) / survival 8-10 yrs Presentation: aphasia, agnosia (visual-processing), apraxia (disorder of skilled movement, tools use), personality changes (passivity, stubbornness, hostility, paranoia), delusions (up to 50%, early onset predicts rapid deterioration), depression/anxiety (40%), hallucinations (25%) Motor rigidity and postural instability mimicking Parkinsonism occurs in 30%, usually progresses more rapidly (early extrapyramidal signs suggests atypical variant or other neurological disease) Pathology: decreased ACh activity (with increased butyrylcholinesterase activity) / neuritic plaques (A,B amyloid, Congo Red, Maltese cross birefringence / neurofibrillary tangles (paired helical fragments of hyperphosphorylated tau protein, intracellular) / Hirano bodies (granulovacuolar degeneration) / loss of cholinergic neurons in NB Meynert, loss of serotonergic and dopaminergic neurons in brainstem amyloid deposits in CNS vasculature also Diagnosis: PET with fluorodeoxyglucose (FDG-PET) (93% sensitivity, 76% specificity), MRI only rules out other things (does not diagnose DAT), MMSE and other functional testing Ddx (see dementia): depression, multi-infarct dementia, other neurodegenerative dementia (see below), hypothyroidism, drugs, B12 deficiency, NPH, alcoholism, HIV, syphilis Treatment: Cholinesterase inhibitors (ChEIs) (donepezil, rivastigmine, galantamine) improve cognitive function and global clinical state risperidone reduces psychotic symptoms and aggressive behavior (recent studies 10/6 suggest side-effects may outweigh benefits; but Risperdal has been generally shown to be the most tolerated) SSRI for depression BZ for insomnia www.alz.org DAT Lewy Body Variant More rapid / early onset of extrapyramidal signs (rigidity or tremor) Frontotemporal Degeneration (FTD) Pick’s disease much less common than DAT (1:20) / earlier onset than DAT / course from 2-10+ yrs Presentation: disinhibited behavior / +/- cognitive impairment on testing / aphasia and personality changes usually precede memory impairment (opposite of DAT) Radiology: atrophy of frontal/temporal lobes (sparing of posterior 1/3 of superior temporal gyrus) / can be asymmetric / left > right in 60% of cases Pathology: classified into three type A, B, C / pick cells (chromatolytic or ballooned neurons) / Pick bodies (argyrophilic, tau-positive inclusions) Other FTDs: Primary progressive aphasia (usually without dementia) Semantic dementia Frontal lobe dementia Corticobasal ganglionic degeneration FTD with parkinsonism linked to chromosome 17 Huntington’s Chorea General: onset 35-40 yrs / severe progressive atrophy of caudate and putamen / non-progressive reduction in brain weight in all grades Genetics: short arm of chromosome 4 / CAG triplet repeat / shows anticipation Molecular: loss of medium spiny GABAergic, sparing of large aspiny cholinergics in striatum Presentation: small writhing movements (athetosis) > choreoform jerking movements Radiology: caudate atrophy on CT scan (very reliable finding) Labs: triplet repeat test can rule out disease Parkinson’s Disease General: 500,000 in US Presentation: 1) bradykinia 2) slow thinking 3) rigidity 4) loss of balance 5) tremor 30% get dementia (atrophy of brain stem and cortex) can cause low back pain, leg pain that is often confused with other entities (treatment is more PD meds) central and/or peripheral autonomic insufficiency (see treatment for Shy-Drager’s) gait is shuffling, festinating (versus apractic gait of NPH) may have small handwriting (micrographia) Pathology: depigmentation of substantia nigra (pars compacta) and locus ceruleus / Lewy bodies (also in 10% of normal population) Molecular: MPTP converted to toxic MPP+ by MAO-B (inhibited by seligiline and smoking) Treatment: L-dopa/carbi-dopa (Synemet): benefits are immediate, do not stop abruptly to avoid risk of NMS) Artane and Cogentin: can help restore balance of Ach activity psychosis secondary to PD medication seems to respond best to atypical antipsychotics Comtan blocks COMT Diffuse Lewy Body Disease Hallucinations (more visual), delusions, ?signs of parkinsonism / antipsychotics may actually worsen underlying disease Parkinsonism-dementia form of ALS that occurs in Guam and Japan / no amyloid accumulation Parkinsonism-like syndromes Post-Encephalitic Parkinsonism neurofibrillary tangles / Lewy bodies rare Striatonigral Degeneration no Lewy bodies / pigmental putamenal atrophy (form of MSA) / does not respond to L-dopa Progressive Supranuclear Palsy (PSP) akinesia, opthalmoparesis, dementia / globose type of neurofibrillary tangle Hallervorden-Spatz disease childhood dystonic syndrome / discoloration of globus pallidus and pars reticulata / axonal spheroids Multiple System Atrophy Spinocerebellar ataxia type 1 (olivopontocerebellar atrophy) most common form of MSA / ataxia, rigidity, oculomotor / CAG triplet expansion / AD Shy-Drager’s syndrome nigral disease (Parkinsonism), ANS symptoms (neuronal degeneration) Treatment: stop BP meds, increase dietary salt , waist-high compression stockings, fludrocortisone 0.1 to 0.5 mg qd, increase water intake, small but frequent meals, avoid excessive heat, avoid Valsalva maneuver, elevate head of bed, correcting anemia / in some cases, L-dopa/carbi-dopa may actually worsen ANS symptoms Friedreich’s ataxia most common inherited progressive ataxia / AR / onset before 20s / GAA repeats / loss of frataxin function / Symptoms: cardiomyopathy (arrhythmias, EKG changes), skeletal deformities, DM Acute cerebellar ataxia viral infection, brief duration / less than ½ of cases show increased WBC’s in CSF Other Atypical Dementias Creutzfeldt-Jakob Disease (CJD) General: prions from infected tissue (cannibalism, cow brains, corneal transplants) / familial form exists / other prion diseases include Gerstmann-Straussler-Scheinker syndrome Incidence: 1 in 167,000 (maybe growing) Presentation: personality changes (irritability), somatic sensations, dementia, motor signs (myoclonus, Parkinson’s-like, etc) Diagnosis: brain biopsy only definitive method EEG: slowing and periodic sharp complexes are diagnostic, but may be absent early on Course: rapidly progressive over 1-2 years; no treatment Dialysis encephalopathy syndrome aluminum-containing phosphate binding gels used in dialysis / usually fatal Download 3.95 Mb. 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