Frequency and causes of early-onset dementia in a tertiary referral center in Athens.

Objective: To investigate the frequency and causes of early-onset dementia (EOD) in consecutive patients in a highly specialized dementia referral center, focusing on unusual cases, particularly with early and/or rapid onset, in Athens, Greece.

Methods: Patients referred for dementia diagnosis according to specific referral criteria during a 3 years period. We examined the distribution of patients diagnosis and differences in sex, education, dementia severity, cognitive function, and the duration of disease (from onset to referral) between the EOD (<65 y) and the late-onset dementia (LOD) groups.

Results: From a total of 260 consecutive demented patients, there were 114 EOD patients or 44% of all demented patients. No significant differences were observed between the EOD and LOD groups in cognitive or behavioral measures. However, the duration from onset to consultation was significantly longer in the EOD group. Also, in the EOD group, the rates of patients with Alzheimer disease and Parkinson disease dementia were relatively low and the rate of patients with frontotemporal lobar degeneration was relatively high and the proportion of secondary dementias was high.

Conclusions: We conclude that EOD patients are more likely to be seen in specialized settings. The underlying diseases are considerably different in EOD compared with LOD. Secondary causes are often found in patients with EOD. Patients with EOD had an unexpectedly longer time-to-diagnosis than patients with LOD. This argues for a need of better education about the clinical presentation of dementia in the young and middle aged.