Frontotemporal Dementias: A New Clinical Syndrome?

The frontal lobe dementias (FLDs) are a group of disorders that have received considerable attention recently. Diagnosis is based on the presence of behavioral and cognitive disturbances associated pathologically with focal neuronal loss and gliosis without any inclusion bodies. Reports describing FLD differ regarding its clinical features, cognitive disturbances, and neurophysiological and neuropathological characteristics. The authors review the existing literature on FLD and emphasize the similarities and differences between reports. The heterogeneity of this condition as currently described is addressed, and arguments supporting the concept of FLD as a syndrome more appropriately called frontotemporal dementia are discussed. The authors present the development of a more rigid clinical definition of this syndrome using well-defined criteria as the first step toward understanding better this group of disorders.