Hospital admission circumstances and prevalence of frontotemporal lobar degeneration: a multicenter psychiatric state hospital study in Germany

Frontotemporal lobar degeneration (FTLD) is a heterogenous, non-Alzheimer's disease, dementia complex with variable clinical presentation. We carried out a prospective nationwide hospital-based clinico-epidemiologic study in geriatric psychiatry to estimate the prevalence and admission circumstances of patients with FTLD. During a 4-week period 33 patients with clinical FTLD were prospectively ascertained in 36 psychiatric state hospitals in Germany with a total catchment area of >20,000,000 people. The relative portion of FTLD patients within the primary dementia population accounted for 1.9%. The estimated prevalence of FTLD in Germany was 47.9/100,000 population aged between 45 and 79 years. The admission circumstances were mainly behavioral disturbances (54.5%), unclear syndromes of dementia (18.1%) and further remarkably heterogeneous psychiatric syndromes. FTLD is a common cause of dementia in geriatric psychiatry with a variable clinical presentation that could mimic most of the major psychiatric diseases. Patients with FTLD may be older than previously assumed (mean age at admission 63.9 years) and show their maximum age-related prevalence between 60 and 70 years (78.7/100,000).