Long-term effects of partial callosal lesions. Preliminary report.

Ten patients with partial callosal lesions were investigated with a broad scale neuropsychological assessment. Nine patients with a variety of lesions affecting midline structures have been operated using a direct transcallosal approach, one patient with a callosal lipoma remained unoperated. Sophisticated studies of the interhemispheric transfer of somaesthetic and perceptual motor tasks, as well as psychometric testing related to parameters of memory and attention performance were applied. The results indicate that there is no clear correlation between the site of callosal lesion and clinical symptoms. Although special disconnecting symptoms due to callosal dissection could be found, they didn't reach clinical significance. The most severe symptoms of impairment were caused by the extracallosal pathology. The results indicate that the transcallosal approach is a safe and feasible alternative in the management of pathological lesions in the midline region.