Unequal distribution of cognitive deficits in vascular dementia--is this a valid criterion in the ICD-10?

Abstract

Objective: To investigate the appropriateness of the ICD-10 criterion for vascular dementia which requires unequal distribution of deficits between different domains of cognitive function.

Design: Cross-sectional comparative study.

Setting: Referrals to a specialist memory clinic in Sheffield and a community sample of patients from a general practice population in Melton Mowbray.

Method: The CAMCOG part of the Cambridge mental disorders of the elderly examination (CAMDEX) was assessed for 131 Sheffield subjects and 396 Melton Mowbray subjects to examine both total variability and differences between individual subscale items. Depression was also examined as this was a potential confounding factor.

Results: After adjustment for age, sex and depression scores, there were no significant differences between vascular dementia subjects and Alzheimer's disease subjects at either centre for total variability of cognitive deficits and little difference between diagnoses for individual subscale items. In Sheffield, subjects with vascular dementia had significantly higher depression scores compared to those with Alzheimer's disease.

Conclusions: The usefulness of the concept of unequal deficits as a diagnostic criterion for vascular dementia in routine clinical practice is doubtful.