Clinical aspects of argyrophilic grain disease.

Argyrophilic grain disease (AGD) is a dementia in the senium characterized by limbic involvement in the form of massive occurrence of argyrophilic and tau-positive grains in the neuropil. The main affected areas in the limbic system are the hippocampal as well as entorhinal regions, and subsequently the amygdaloid nucleus, where mild to moderate degrees of tissue degeneration are also often observed. Retrospective evaluation of 4 patients with AGD revealed common clinical features which consist of memory disturbance, relatively preserved cognitive function and personality change characterized by emotional disorder with aggression or ill temper. Such clinical characteristics are consistent with limbic involvement, and therefore AGD is thought to be a type of limbic dementia. The lack of Klüver-Bucy syndrome, which constitutes the basic part of limbic dementia, may indicate chronic, progressive and mild degeneration in the limbic areas in this disease.