Authors:

GRAHAM, N.L., EMERY, T. & HODGES, J.R.

Reference:

Year of publication:

2004

CBU number:

5711

Abstract:

Objectives. There are inconsistencies in the literature regarding the profile of cognitive impairments in vascular dementia (VaD), and its differentiation from Alzheimer's disease (AD). We aimed to identify (i) the overall profile of cognitive impairment in subcortical VaD as compared to AD, and (ii) the tests which best discriminate between these groups. Methods. A total of 57 subjects participated: 19 subcortical VaD, 19 AD and 19 controls. The VaD and AD groups were matched on the basis of age, education, and general levels of cognitive and everyday functioning. Subcortical VaD was defined on the basis of clinical features (prominent vascular risk factors plus a prior history of transient ischaemic events and/or focal neurological signs) and substantial white matter pathology on MRI. All subjects were administered an extensive battery of 33 tests assessing episodic and semantic memory, executive/attentional functioning, visuospatial and perceptual skills. Results. Despite a minimal degree of overall dementia, both patient groups exhibited impairments in all cognitive domains. The AD patients were more impaired than those with VaD on episodic memory, while the VaD patients were more impaired on semantic memory, executive/attentional functioning, visuospatial and perceptual skills. Logistic regression analyses showed that the two groups could be discriminated on the basis of two tests, the WAIS Logical Memory - Delayed Recall and a silhouette naming test, with 89% accuracy. Conclusions. Subcortical VaD and AD produce distinctive profiles of cognitive impairment which can act as an adjunct to diagnosis. Many of the neuropsychological deficits thought to characterise AD are also found in subcortical VaD.