UNDERSTANDING SYMPTOMS OF MEDIAL FRONTAL-LOBE DISORDER - A CLINICAL CASE-STUDY

A case of anterior communicating artery aneurysm with damage to inferi or medial frontal areas (Brodmann areas 25, 32, 24-inferior) is presen ted. Four prominent deficits are discussed: (I) anterograde amnesia, ( 2) inert perseverative card sorting, (3) motor stereotypies, and (4) r eduplicative paramnesia. These four deficits are discussed as negative or positive symptoms, related either to damage in inferior medial fro ntal (Brodmann areas 25, 32 24-inferior) regions or release phenomena of superior medial frontal (Brodmann areas 6-medial and 24-superior) r egions. It is concluded that the inferior and superior medial frontal regions act as opponent processors, with the inferior (B25, 32) area f unctioning to switch current mental set while the superior (B24-superi or, 6-medial) region functions to maintain current mental set. Testabl e hypotheses about the opponent processor mechanism are suggested, as applied to neuropsychiatric disorders.