[Frontotemporal lobar degeneration: a diagnostic challenge].

Frontotemporal lobar degeneration (FTLD) is a common cause of dementia in population of under 65 years old. FTLD manifests clinically with progressive behavioural problems and personality changes and/or language impairment. There are no disease-modifying treatments for FTLD. Symptomatic treatments such as selective serotonin reuptake inhibitors and atypical antipsychotic agents are frequently used to manage behavioural symptoms. Immunohistochemical findings have clarified neuropathological classification of the disease. Family history of dementia is positive in approximately 30-50% of FTLD cases. Mutations in five different genes are known to cause FTLD, but these mutations seem to be rare in the Finnish population.