Auditory ear extinction in lacunar syndromes.

A dichotic listening test was administered to 28 patients with lacunar syndromes in order to contribute to the investigation of the subcortical route of interhemispheric auditory pathways. Topographic study showed that lesions in the external capsule or in the anterior limb of the internal capsule in both hemispheres produced left ear extinction. The possibility that some of the auditory fibres travel through the external capsule, as well as the anterior limb of the internal capsule, before crossing the contralateral cerebral lobe is suggested.