Frontotemporal dementia: a clinically complex diagnosis.

Objective: To compare the time taken to establish a clinical diagnosis of Frontotemporal dementia (FTD) relative to a diagnosis of early onset Alzheimer's dementia (AD).

Methods: The data came from 89 patients under the age of 65 years, 52 of whom met the Manchester-Lund criteria for Frontotemporal dementia; 20 of these came from Lund University Hospital in Sweden. The other 32 patients with FTD along with 37 subjects who fulfilled the ICD-10 criteria for early onset Alzheimer's disease were recruited from four memory clinics and two neurology departments in Norway.

Results: For FTD patients in Norway it took 59.2 months (SD 36.1) from the onset of illness until a clinical FTD diagnosis was made. The corresponding time period for FTD patients in Sweden is 49.5 months (SD 24.5) and for AD patients in Norway 39.1 months (SD 19.9). The time from the first visit to a medical doctor until a diagnosis was made for the FTD patients in Norway was 34.5 months (SD 22.6), for the Swedish FTD patients 23.1 months (SD 22.4) and for the AD patients 25.9 months (SD 13.1). In all, 71% of FTD patients and 30% of AD patients initially received a non-dementia diagnosis.

Conclusion: More knowledge about early presenting cognitive and behavioural signs of FTD is needed in both primary and secondary health care to reduce the time period needed to establish a clinical diagnosis of FTD.