The clinical diagnosis of vascular dementia: A comparison among four classification systems and a proposal for a new paradigm

Throughout the 1990s a variety of schemes for the diagnosis of Vascular Dementia (VaD) were proposed, including the ADDTC criteria for Ischemic Vascular Dementia, the NINDS-AIREN criteria for Vascular Dementia, Bennett's criteria for Binswanger's disease, and the ICD-10 criteria for Vascular Dementia. We undertook a retrospective analysis of a series of ambulatory outpatients with dementia to determine the prevalence with which patients were diagnosed by each of these diagnostic schemes, and to survey the clinical characteristics associated with VaD. We found that the diagnostic schemes for VaD were not interchangeable; patients diagnosed with VaD using one set of criteria were not necessarily diagnosed with VaD using other criteria. The most common clinical characteristics associated with VaD, regardless of the diagnostic scheme that was used, were hypertension, extensive periventricular and deep white matter alterations on MRI (leukoaraiosis), and differential impairment on neuropsychological tests that assess the ability to establish/maintain mental set and visuoconstruction, with relatively higher scores on tests of delayed recognition memory. Interestingly, the majority of VaD patients obtained low scores on the Modified Ischemic Scale, since cortical infarcts and a history of a sudden onset and/or step-wise decline in cognitive function were rare. We conclude that the current diagnostic schemes for VaD do not necessarily consider the heterogeneous nature of VaD. A new paradigm that seeks to describe, in addition to diagnosing dementia associated with cerebrovascular disease is discussed.