[Semantic dementia].

Semantic dementia (SD) is characterized by an assymetric atrophy of the temporal lobes and, clinically, by an impairment of the semantic memory associated to psychobehavioral symptoms. The concept of SD was defined in 1989 and still remains controversial. Some authors consider DS as a specific entity, others as part of the frontotemporal dementia (FTD) or a variant of the progressive aphasia syndrome.