The frontotemporal dementias in a tertiary referral center: classification and demographic characteristics in a series of 232 cases.

BACKGROUND: Frontotemporal lobar degeneration (FTLD) comprises of behavioral variant frontotemporal dementia (bvFTD) and primary progressive aphasia (PPA) with its 3 main variants, namely nonfluent/agrammatic (naPPA), semantic (svPPA) and logopenic (lvPPA). Recently a clinical syndrome with predominant right temporal atrophy was recognized (rvFTD). FTLD often overlaps with parkinsonism plus syndromes such as corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP), as well as with motor neuron disease (FTD-MND). While FTLD syndromes were thought to be rare and difficult to diagnose ante mortem, revised diagnostic criteria as well as recent studies highlighted the plausibility of accurate clinical diagnosis.
METHODS: 232 FTLD patients were assessed from January 1, 2003 to December 31, 2010 in the Neurology Department of a tertiary referral center. Patients were classified as bvFTD, naPPA, svPPA, lvPPA, CBD/PSP and rvFTD and their demographic characteristics were analyzed.
RESULTS: From the 232 patients, 111 (47.8%) were diagnosed with bvFTD, 56 (24.1%) with naPPA, 21 (9.1%) with svPPA, 6 (2.6%) with lvPPA, 20 (8.6%) with CBD or PSP and 18 (7.8%) with rvFTD. 44% of the patients were under 65 years old at onset of symptoms, while only 4.3% reported family history of dementia. FTLD subgroups did not differ with respect to demographic characteristics, but early onset cases had higher educational level. DISCUSSION: FTLD represents a syndrome with different but clinically distinguishable phenotypes. Cultural, educational and socioeconomic status differences might regulate patients' access to medical care and therefore influence age of reported onset and prevalence of FTLD in clinical studies. High clinical alertness and sensitive neuropsychological tests could lead to timely clinical diagnosis in a common presenile type of dementia.