DIAGNOSTIC-ACCURACY OF ALZHEIMERS-DISEASE - A NEUROPATHOLOGICAL STUDY

This prospective study focused on the accuracy of diagnosis of Alzheim er's disease (AD). We recruited 100 dementia patients and 20 controls who underwent a systematic evaluation. The clinical diagnosis of proba ble AD or possible AD according to the NINCDS-ADRDA criteria was assig ned In 69%; of the patients, 21% had vascular dementia (VaD) (DSM-III- R) and 8% had mixed AD-VaD; only 2 patients (2%) had the Lewy body var iant of AD (AD-LB). During a 3-year period 57 patients died, 53 of the m (93%) being autopsied. Neuropathological examination according to th e CERAD criteria showed definite AD in 27 out of 28 (96%) patients dia gnosed as probable AD. In the possible AD group, the diagnostic accura cy was also high, 86% showed at least some degree of AD pathological a lterations. The neocortical senile plaque scores correlated significan tly with tangle scores in patients with AD pathology, and there was a significant negative correlation between age of onset and neocortical tangle scores. The concordance between the clinical diagnosis and path ological findings was clearly lower in VaD than in AD. In the clinical VaD group, 8 of 10 patients had at least some degree of AD changes to gether with vascular changes and only 2 of 10 patients had pure VaD. T his study confirms the high accuracy of the NINCDS-ADRDA criteria for diagnosing AD. In contrast, uncertainty in the clinical diagnosis of V aD should be taken into account, for example, in drug trials with VaD patients.