Objective: To study the incidence and neuropathological features of Alzheimer's disease in Chinese and the significance of silver and amyloid beta-protein staining for the pathological diagnosis of Alzheimer's disease.
Methods: Among 445 autopsy cases above 60 years in age (including 60) collected from 1982-1998 in the Department of Pathology, Beijing Hospital, totally 29 cases were diagnosed as Alzheimer's disease pathologically (6.5%), accompanying with a history of mental deterioration and the histological changes in certain areas of the brain fulfilling the Khachaturian or Mirra criteria. Tissue blocks were taken from 6 standard regions of the brains for Bodian, Bielschowsky and amyloid beta-protein immunostaining. Senile plaques and neurofibrillary tangles were quantified.
Results: Four main types of senile plaques were noticed and the result by amyloid beta-protein immunostaining was considered more sensitive than that of the silver impregnation staining. The former one enabled to demonstrate all the 4 types of senile plaques, while silver impregnation staining could only demonstrate clearly the primitive and neuritic plaques, but not the small diffuse and burn-out plaques. The senile plaques were noticed to be focused in the hippocampus, superior temporal gyrus and middle frontal gyrus while the neurofibrillary tangles, were mainly obtained in the hippocampus, temporal cortex and amygdaloid. Cerebral amyloid angiopathy was found in 25 out of 29 Alzheimer's disease cases.
Conclusions: Alzheimer's disease may be the main cause of dementia among the elders in Chinese and immunostaining for amyloid beta-protein pretreated with formic acid may set a high value on the pathological diagnosis of Alzheimer's disease.