Progressive dysarthria. Case reports and a review of the literature

Two patients presenting with progressive dysarthria as the single initial manifestation of a neurodegenerative condition are described. The nature of the dysarthria as well as the additional symptoms that developed in the course of the disorder are very different in these two cases. Nevertheless, neuroimaging findings are strikingly similar and suggest bilateral involvement of posterior inferior frontal lobe structures, mainly in the dominant cerebral hemisphere. The clinical syndrome of these patients can therefore be considered an example of frontotemporal degeneration presenting without dementia or compartmental alteration, at least in the early stages. This broadens the clinical spectrum of frontotemporal degeneration and demonstrates the need for a syndromal subclassification of this nosological entity.