No abstract

Duration of survival in patients who had died of presenile Alzheimer''s disease (AD) or presenile multi-infarct dementia (MID) in 13 mental hospitals in Scotland are described and contrasted. The duration of survival was significantly longer from symptom onset to death in AD (mean 7.4 years) than in MID (mean 5.8 years). Most of this difference was accounted for by a longer duration between symptom onset and presentation to hospital care in AD (mean 3.2 years) than in MID (mean 2.4 years). Age at onset and gender did not influence survival duration in AD or MID.

The observed differences in incidence of AD PSD between Scotland's regions are real and some localities have a higher incidence, mostly in central Scotland.

We estimated survival of patients with early onset Alzheimer’s disease (AD) or vascular dementia (VaD) presenting to psychiatric hospitals in Scotland (1974–1988) and related this to age, gender and socio-economic variables. Hospital records of 1794 early onset dementia patients were reviewed. We identified 451 patients with early onset AD and 384 with VaD. Survival to death was calculated from symptom onset and presentation. Small geographical areas (postcode sectors) were classified by urban/rural category and deprivation score. Five-year survival from presentation of early onset AD was 32% for men and 43% for women compared to 22% for men and 36% for women with VaD. We conclude that increased age at presentation was associated with shorter survival in early onset AD and VaD. Socio-economic deprivation was associated with longer survival in VaD. The effects of urban/rural score were accounted for by the major effects of socio-economic deprivation.

SUMMARYA national retrospective survey of hospital records was used to select those patients with presenile dementia who had undergone neuropathological examination. The National Institute of Neurological and Communicative Disorders and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) clinical criteria for probable Alzheimer's disease and a Hachinski score were applied to each record before the neuropathological diagnosis was known. A discriminant analysis, which entered the criteria as variables, was performed. The diagnostic accuracy of the clinical criteria was compared before and after discriminant analysis. One thousand six hundred and seventy-one records were scrutinised of which 61 patients had undergone neuropathological examination. NINCDS -ADRDA criteria had a diagnostic accuracy of 72% (specificity 88%, sensitivity 61%) compared to 77% (specificity 80%,, sensitivity 75%) after analysis. NINCDS-ADRDA criteria together with the Hachinski score had an accuracy of 72Yn (specificity 61%, sensitivity 88%) compared to 83.6% (specificity 76%, sensitivity 89%) after analysis. Variables of highest discriminating value were the Hachinski score, presence of coexistent neurological disease and presence of coexistent systemic disease. The results highlight limitations of current clinical criteria used to diagnose Alzheimer's disease and suggest that substantial improvements are possible.