Linguistic and non-linguistic abilities in a patient with early left hemispherectomy.

A patient who underwent early removal of the left hemisphere because of Sturge-Weber syndrome was submitted to detailed linguistic and visuospatial batteries. The performances were compared to performances of subjects matched for age, education and IQ, but without focal cerebral lesions. Language was mildly impaired but to the same extent as in IQ controls. On the contrary, visuospatial abilities were clearly worse than in IQ controls, and the most preserved visuospatial abilities seemed to be the less sophisticated ones. Non literal comprehension of language, a function generally attributed to the right hemisphere, was intact. This same pattern, that is, preservation of language and impairment of visuospatial abilities, also seems to occur in subjects who have undergone surgical removal of the right hemisphere; in other words, the cognitive pattern seems the same regardless of which hemisphere is removed. These observations suggest that no matter which hemisphere is removed, functional reorganisation follows a hierarchical criterion which privileges the linguistic function, and the visuospatial functions most essential for independent survival.