Frontotemporal dementia: a clinicopathological review of four postmortem studies.

Frontotemporal dementia is a progressive dementing illness characterized clinically by personality change, disinhibition, and apathy. Neuropathologically, neuronal cell loss, astrogliosis, and microvacuolation are present in the superficial frontotemporal cortical layers, with variable involvement of subcortical and limbic structures. The clinical picture and anatomical distribution of the degenerative changes, as well as motor neuron involvement, differentiate four neuropathological groups: 1) frontal lobe type, 2) thalamostriatal type, 3) motor neuron type, and 4) asymmetrical type. The authors review the results of four large postmortem studies with a special emphasis on cliniconeuropathological correlation.