Speech and other functions after left (dominant) hemispherectomy.

The development of hemispherectomy for glioma (mostly in adults) by Dandy (1928) and later for infantile hemiplegia by Krynauw (1950) permitted comparisons of effects of removal of either hemisphere on both the adult and young brain. Reviews of over 300 cases of hemispherectomy (e.g., White, 1961; McFie, 1961) reflect the 'functional plasticity' of the young brain. Continuing development of higher and lower level cerebral functions after right or left hemispherectomy in children with gliomas as well as infantile hemiplegia has been reported by most writers. A 10-year-old left-handed girl (Gardner Karnosh, McClure, and Gardner, 1955) and a 14year-old right-handed boy (Hillier, 1954) were reported living 53 and 27 months respectively with functional speech after left hemispherectomy for glioma. Obrador (1964) described transfer of language to the 'non-dominant' hemisphere as the rule up to the age of 15. However, there is general agreement that in the adult this plasticity is largely lost and that dominant hemispherectomy is to be discouraged. Right hemispherectomy in the adult for glioma has been much more frequently reported. This is followed by the expected severe left hemiplegia and hemianopia but ability to walk was often acquired, and some patients developed useful movement of the left arm. The greater reluctancetoremovethe lefthemisphere in adults reflects widespread beliefs that the integrity of various dominant hemisphere structures is necesary for many functions including receptive and expressive language (oral and written), 'higher' mental functions (Smith, 1966), control of right and left-sided purposeful movements (Liepmann, 1905), arithmetical reasoning, and discrimination of colours (Hecaen and Ajuriaguerra, 1964). Numerous cases with left-sided focal lesions have been cited to support these beliefs. Continuing survival over seven months after left hemispherectomy in the case described below provided an opportunity to study the capacity of the minor hemisphere to maintain or acquire speech and other non-language cerebral functions. CASE REPORT