Multi-infarct dementia: a reappraisal.

Multi-infarct dementia (MID) may not be the only or even the most important form of vascular dementia. Vascular factors probably contribute to dementia through cerebral infarcts and white matter changes more often than they cause it. More subtle ischemic insults affecting synapses, cells, or protein synthesis without causing frank infarction remain plausible but unproven postulates. Lest we regress to vague and comforting notions of silting blood vessels and ailing neurons, let us recognize that although MID may not explain all of vascular dementia, it has the virtue of being a firm, testable concept. As such it has not been overthrown or even seriously challenged. But it is time for a reappraisal.