Distinctive cognitive profiles in Alzheimer's disease and subcortical vascular dementia.
BACKGROUND
There are inconsistencies in published reports regarding the profile of cognitive impairments in vascular dementia, and its differentiation from Alzheimer's disease.


OBJECTIVE
To identify the overall profile of cognitive impairment in subcortical vascular dementia as compared with Alzheimer's disease; and the tests which best discriminate between these groups.


METHODS
57 subjects participated: 19 with subcortical vascular dementia, 19 with Alzheimer's disease, and 19 controls. The dementia groups were matched for age, education, and general levels of cognitive and everyday functioning. Subcortical vascular dementia was defined by clinical features (prominent vascular risk factors plus a previous history of transient ischaemic events or focal neurological signs) and substantial white matter pathology on magnetic resonance imaging. All subjects were given a battery of 33 tests assessing episodic and semantic memory, executive/attentional functioning, and visuospatial and perceptual skills.


RESULTS
Despite a minimal degree of overall dementia, both patient groups had impairments in all cognitive domains. The Alzheimer patients were more impaired than those with vascular dementia on episodic memory, while the patients with vascular dementia were more impaired on semantic memory, executive/attentional functioning, and visuospatial and perceptual skills. Logistic regression analyses showed that the two groups could be discriminated with 89% accuracy on the basis of two tests, the WAIS logical memory--delayed recall test and a silhouette naming test.


CONCLUSIONS
Subcortical vascular dementia and Alzheimer's disease produce distinctive profiles of cognitive impairment which can act as an adjunct to diagnosis. Many of the neuropsychological deficits thought to characterise Alzheimer's disease are also found in subcortical vascular dementia.
Graham
N L
NL
University of Cambridge Neurology Unit, Addenbrooke's Hospital, and MRC Cognition and Brain Sciences Unit, 15 Chaucer Rd, Cambridge, UK.
Emery
T
T
Hodges
J R
JR
D000368:Aged; D000544:Alzheimer Disease / Q000150:complications* / Q000523:psychology*; D001288:Attention; D003072:Cognition Disorders / Q000209:etiology* / Q000503:physiopathology*; D015140:Dementia, Vascular / Q000150:complications* / Q000523:psychology*; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000523:psychology; D008875:Middle Aged; D009483:Neuropsychological Tests; D013028:Space Perception; D014796:Visual Perception