University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

175

Pages:

2
Author:

Mariam A.

Prion disease   Also known as transmissible spongiform encephalopathy. Group of disorders with the same basic pathogenesis: o CNS accumulation of abnormal form of pion (neuronal protein). o Prions undergo conformational change by either inoculation (from infected) or spontaneous change. o Conformational change leads to relative resistance to protease digestion. o Abnormal prion then transforms other normal prions (therefore infectious).  Histopathology: o Cytoplasmic vacuolations of neurons, seen as spongiform change of the neuropil. o Extracellular deposits of prion aggregates. Creutzfeldt-Jakob disease: o Usually sporadic, though familial forms and iatrogenic transmission reported. o Frequency of sporadic cases is 1 in a million.    Variant VJD: o Much publicised, with evidence linking this with bovine spongiform encephalopathy (mad cow diseases). o In contrast to usual CJD, seen in younger patients with slower disease progression. Kuru:  o Endemic form described in the Fore tribe of the highlands of PNG. o Secondary to cannibalism. Others (inherited forms): o Gerstmann Straussler Scheinker Syndrome. o Fatal familial insomnia. Toxic/metabolic  Alcohol: o Wernicke encephalopathy. o Korsakoff psychosis; due to thiamine deficiency in chronic alcohol abuse.  Hepatic encephalopathy.  Renal failure: o Uremic encephalopathy. o Dialysis dementia; related to high brain aluminium content. Trauma  Diffuse axonal injury: o Diffuse swelling of aoxons within hours after injury. o Can be caused by acceleration alone (i.e. without impact).  Chronic subdural haematoma.  Dementia pugilistica (“punch drunk” syndrome). o Consequence of repeated head trauma over a protracted time period (e.g. boxers). o Variety of pathological changes can be seen, including accumulation of NPs and NFTs. Tumours  Variety of primary and secondary lesions.  Paraneoplastic encephalitis. Conclusions  Given the ageing Australian population, dementia is projected to be an escalating health issue.  Dementia can be caused by a variety of diseases that are categorised into several broad groups.  The single most important cause of dementia in the elderly is AD, followed by DLB and vascular dementia.