A case report of crossed aphasia, grasping, and intermanual conflict with the left hand

There are few reports describing the coexistence of alien hand syndrome (AHS) and crossed aphasia. The patient was a right-handed woman in her seventies. Following an infarction involving the medial right frontal lobe and the genu of the corpus callosum, she developed groping, grasping, and intermanual conflict (IC) in the left hand, along with crossed aphasia. The groping and grasping may have resulted from impaired inhibition due to supplementary motor area damage, whereas IC may have arisen from disrupted interhemispheric information transfer. The absence of apraxia in the right hand and the presence of IC in the left hand suggested that praxis functions were lateralized to the left hemisphere. The symptoms of crossed aphasia resembled those typically observed after left hemisphere damage, raising the possibility that language function was lateralized to the right hemisphere. The AHS symptoms in the left hand were considered to have resulted from different mechanisms, while the aphasia may have emerged due to atypical lateralization of language.