Akinetic mutism associated with bicingular lesions: clinicopathological and functional anatomical correlates

The clinical symptoms and neuropathological findings of three patients suffering from akinetic mutism were summarized. The patients showed almost absolute mutism and immobility and were unable to communicate in any way. The neurological signs varied from case to case. The pathological features common to all of the cases were bilateral lesions of the rostral part of the anterior cingulate gyri which overlapped onto the neighboring supplementary motor area, while differing as regards other damage. With the help of more recent neurobiochemical findings we tried to analyze the pathomechanism of akinetic mutism on the basis of the structures damaged. There seems to be an anatomic correspondence between the mesolimbocortical dopaminergic system and the circumscribed bilateral lesions of the medial prefrontal cortex. The study suggests that damage of the mesolimbocortical dopaminergic terminal fields in the anteromedial frontal cortex is essential for this specific type of akinetic mutism.