Clinical diagnosis of dementia

Abstract

This paper presents recommendations deriving from the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia, concerning the clinical diagnosis of dementia. There are currently no universally accepted biological or radiological markers of dementia. In the absence of these, the diagnosis of dementia remains a clinical exercise aiming to integrate all available clinical and laboratory information. It is proposed that the currently used National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer’s Disease and Related Disorders Association (NINCDS/ADRA) criteria for diagnosis of Alzheimer’s disease (AD) be retained. The currently available vascular dementia (VaD) diagnostic criteria have variable accuracy. An integrative approach to VaD diagnosis based on all the available evidence (history, vascular risk factors, physical exam, clinical course, neuroimaging, cognitive impairment pattern) is recommended. The separation of Lewy body dementia (DLB) from Parkinson’s disease dementia (PDD) is based on the dominant clinical presenting feature of each syndrome, and relies on the duration of this feature: long duration of parkinsonian “motor” syndrome preceding dementia for PDD versus early/initial dementia accompanied by extrapyramidal symptoms for DLB. It is recognized that it is impossible clinically to characterize DLB with (pathologically) coexisting AD changes. The Frontotemporal group of dementia syndromes are discussed in regards to their typical clinical pictures, recognizing that their neuropathological substrate are not predictable from their mode of presentation. Finally, the particular rapid time sequence of evolution of the dementias due to prior disease is recognized as the clinically most useful distinguishing feature of these syndromes.