Clinical differentiation of primary degenerative and multi-infarct dementia: a critical review of the evidence. Part I: Clinical studies.

For patient care and for research purposes there is an obvious need for a valid and reliable set of clinical criteria to distinguish antemortem between primary degenerative dementia (PDD) and multi-infarct dementia (MID). To this end, specific diagnostic criteria for each have been promulgated in the official nomenclature, and a rating scale devised to differentiate these disorders is in wide use. These efforts suggest a diagnostic capability that is not, however, well supported by the literature. This critical analysis of representative clinical studies and articles published over the past two decades reveals important drawbacks in methodologic approaches and interpretation of data which seriously undermine confidence in making the clinical distinction between PDD and MID.