I read Dr Stewart's article on vascular dementia (Reference StewartStewart, 2002) with great interest. As a recently appointed consultant in old age psychiatry (having been trained in the ‘old’ way about diagnosing vascular dementia, i.e. sudden onset, stepwise deterioration, history of vascular risk factors, etc.), I started noticing a very different presentation of vascular dementia, especially in those with evidence of extensive periventricular disease on computed tomography. These cases commonly present with a range of frontal executive function deficits, with functional psychiatric symptoms of anxiety and depression and sometimes with progressive aphasia, and do not necessarily have the classical history of vascular dementia as described in textbooks.

The importance of the clinical findings is that as clinicians and educational supervisors we need to use more screening tests for frontal executive functions in routine assessments of dementia. In addition to the Mini-Mental State Examination (Reference Folstein, Folstein and McHughFolsteinet al, 1975), verbal fluency and similarities (FAS; Reference Thomas, O'Brien, Jacoby and OppenheimerThomas & O'Brien, 2002) tests are quick ways of testing frontal functions and should be encouraged among all members of a multi-disciplinary team. This has also been recognised in the new Cambridge Examination for Mental Disorder of the Elderly, Revised (CAMDEX-R; Reference Roth, Huppert and MountjoyRoth et al, 1999).

Findings of periventricular ischaemia are controversial as far as their relevance to dementia diagnosis is concerned but patients who present with marked frontal functioning deficit and evidence of periventricular ischaemia on computed tomography should receive a diagnosis of vascular dementia. It is now known that ischaemia in periventricular areas interferes with the cortico—striato—thalamo—cortical loops which, in turn, affect functioning of frontal lobes.