[Cognitive disorders appearing before the age of 65 in patients of the Alzheimer Centre of the VU Medical Centre: diagnoses and clinical characteristics]. / Cognitieve stoornissen optredend vóór de leeftijd van 65 jaar bij patiënten van het Alzheimercentrum van het VU Medisch Centrum: diagnosen en klinische kenmerken.

ABSTRACT

OBJECTIVE: To obtain a profile of the causes and clinical characteristics of cognitive disorders in patients referred to a memory clinic before the age of 65 years. DESIGN: Retrospective case-note study. METHOD: Data were collected from 127 subjects with objective cognitive disorders who visited the Alzheimer Centre of the VU Medical Centre in Amsterdam, the Netherlands, in the period from 1 January 2001 to 31 December 2003 with an onset of complaints before the age of 65. Besides the diagnoses, we investigated the clinical presentations, the occurrence of cardiovascular risk factors, the family history, and the presence of noncognitive neurological signs. RESULTS: The most common causes of cognitive decline under the age of 65 were Alzheimer's disease (46%) and frontotemporal dementia (23%). Vascular dementia was seen in 5% and dementia with Lewy bodies in 2%; 9% had mild cognitive impairment but no dementia. Hypertension and a positive family history for dementia were each present in 40% of the patients. Non-cognitive neurological abnormalities were found only in cases of non-Alzheimer dementia. During the period under investigation, the number of patients with objective cognitive disorders increased more than did the number without a cognitive disorder. CONCLUSION: Within the population of a memory clinic, Alzheimer's disease was the most frequent cause of cognitive decline under the age of 65, followed by frontotemporal dementia. The distribution differed from causes of dementia at an older age, where vascular dementia had the second place.