Left-handedness and variant patterns of cerebral organization: a case study

A left-middle-cerebral artery infarct in a 51-year-old, nonfamilial left-handed man failed to produce aphasia, but did result in imparied visuospatial functioning, construction dyspraxia, mild limb dyspraxia, and temporal/sequential skill dysfunction. The patient also had severe right-sided sensory and body neglect, right-sided hemiparesis, and mildly dysarthric speech. These neuropsychological findings strongly suggest a reversed pattern of cerebral organization. Posterior anatomical size asymmetries were also reversed, in that the right occipitalparietal area was somewhat larger than the left. However, this patient's limb dyspraxia followed no known pattern of cerebral organization. His dyspraxia suggests that control of complex motor skills in nonfamilial left-handers may remain a left-hemisphere or bilaterally represented function, even when other cognitive abilities are reversed.