Akinetic mutism: disconnection of frontal-subcortical circuits.

Akinetic mutism may result from anterior cingulate lesions or a disconnection of the limbic connections projecting from the cingulate through subcortical circuits. Based on nonhuman primate primate tracer studies, ventral pallidal lesions should disrupt the anterior cingulate frontal-subcortical circuit. A patient developed a rigid akinetic mute state caused by bilateral lesions of the globus pallidus interna with ventral extension. The anatomic basis of the patient's clinical findings support a similarity in frontal-subcortical anatomy between humans and nonhuman primates. Isolated pallidal lesions are rare. Future studies should document whether ventral extension below the anterior commissure is associated with a loss of motivation.