Clinical Diagnosis of Dementia: Core Clinical Features and Diagnostic Criteria

Abstract

In dementia of the elderly, the majority of patients with onset around the eighth decade have typical Alzheimer's disease; diagnostic workup is usually simple, and a plain computed tomography brain is sufficient to exclude pathology other than generalised brain atrophy. Advanced neuroimaging is often required when onset occurs at a younger age to confirm a major neurocognitive disorder and non-Alzheimer's disease. The prognosis and trajectory of the latter differs to that of Alzheimer's and, because of the younger age, has important psychosocial implications. Particular clinical features often suggest a non-Alzheimer's diagnosis, and although clinical criteria play a vital role, functional neuroimaging helps reach a definitive diagnosis. A simplified diagnostic chart at the end of this article aims to assist such diagnosis.