Difficulties in the clinical diagnosis of vascular dementia and dementia of the Alzheimer type--comparison of clinical classifications.

The article compares the diagnostic criteria of dementia (DSM-III-R; DSM-IV; ICD-10; NINCDS-ADRDA; CERAD), dementia of the Alzheimer type (DSM-III-R; DSM IV; ICD-10; NINCDS-ADRDA; CERAD) and vascular dementia (DSM-III-R; DSM IV; ICD-10; NINDS-AIREN and ADDTC). There are major differences with respect to the definition of dementia, minor differences with respect to the definition of DAT and major disagreement concerning the definition of vascular dementia resulting in significant variability in the prevalence of the respective disorders. In patients with leukaraiosis and subcortical infarcts the differentiation of vascular and degenerative dementias is particularly difficult. In these cases onset and progression of dementia are often gradual and focal signs and symptoms are not always found. "New diagnoses" such as dementia with Lewy bodies, hippocampal sclerosis. CADASIL and dementia lacking distinctice histological features should be considered.