[Frontotemporal lobar degeneration: a descriptive study of 42 patients]

Frontotemporal lobar degeneration (FTLD) is considered to be the second cause of presenile dementia. In spite of the great interest it has generated over the last few years, few studies have been published in our country.

A descriptive retrospective study of 42 patients with FTLD evaluated in our unit during the period 1996-2006 was performed.

Thirty one patients presented with frontal variant FTLD (FTD), eigth with non-fluent progressive aphasia and three with semantic dementia. Mean age at onset was 56 years, diagnostic delay 3.5 years and mean survival 6.8 years. 35% had a family history suggestive of dementia. In patients with FTD the clinical expression was a combination of behavioral and personality disorders together with language impairment. Magnetic resonance imaging showed frontal and/or temporal atrophy in 62% of cases and SPECT showed frontal and/or temporal hypoperfusion in 75%. The P301L tau mutation was detected in four patients (two of them siblings) and the A303AfsX57 progranulin mutation in one. Necropsy was performed in five patients, revealing FTLD with ubiquitininmunoreactive inclusions (FTLD-U) and motor neuron disease in two cases, FTLD-U with <> shaped intranuclear inclusions in the case with the progranulin mutation and FTLD tauopathy with predominance of 4R tau in the remaining two, both with the P301L mutation.

Our results are similar to those of the great European series. FTLD must be suspected in presenile patients with prominent behavioral and/or language disorders. Neuroimaging supports the diagnosis in the majority of cases. The huge sociofamiliar impact of FTLD, presenile onset, high frequency of familial history of dementia and possibility of genetic study and counseling highlight its clinical relevance.