[Frequency of different forms of dementia at the Department of Neuropathology of the Hungarian National Institute of Psychiatry and Neurology during a 3-year period]

Abstract

Background: Dementia is an increasing problem in society. The underlying cause of dementia may be difficult to diagnose during life. Only neuropathologic examination gives definite diagnosis. Differences in the reported frequency may be related to factors such as the age or gender of subjects with dementia.

Materials and methods: In our neuropathology-based study we examined 156 consecutive subjects clinically diagnosed with dementia during a 3-year period. Using histopathological criteria we calculated the frequencies of various disorders causing dementia. We studied the effect of age and gender on these frequencies.

Results: Alzheimer's disease was the most frequent pathologic finding (57.7%) followed by vascular dementia (43%); diffuse Lewy body disease (15.4%); argyrophilic grain dementia (12.1%), various forms of frontotemporal dementia (5.7%); and other (4.5%). The latter comprise prion disease, alcoholic encephalopathy, and hippocampal sclerosis. Mixed pathology was common: concomitant Alzheimer's disease was present in 41.6% of diffuse Lewy body disease cases and in 49.2% of vascular dementia patients. Pure disease forms are rare: Alzheimer's disease: 26.3%, vascular dementia: 17.3%, diffuse Lewy body disease: 5.1%, argyrophilic grain dementia: 2.5%. Females were overrepresented among those with Alzheimer's disease with age at death above 75 years (p < 0.02), while males were overrepresented in patients below 75 years with vascular dementia (p < 0.05).

Conclusions: Our study indicates that the frequency of neurodegenerative dementias is high in the examined patients, but vascular pathology frequently influences the clinical course.