Effect of lateralized cerebral damage upon contralateral and ipsilateral sensorimotor performances.

Three groups of 50 adult patients with either lateralized vascular, neoplastic, or traumatic cerebral lesions were compared with respect to their contralateral and ipsilateral sensorimotor functioning. The present study investigated the extent of sensorimotor deficits associated with different types of naturally-occurring damage to the right and left hemispheres. Sensorimotor abilities were assessed using tests from the Halstead-Reitan Neuropsychological Test Battery. Intergroup comparisons showed a differential pattern of sensorimotor impairment in which the cerebrovascular group was most impaired, followed by the neoplastic group, with the trauma group demonstrating the least impairment. Interhemispheric comparisons among the lesion groups consistently demonstrated right cerebral hemisphere predominance for contralateral and ipsilateral sensorimotor functions. The findings indicate clearly that the sensorimotor functions of the two cerebral hemispheres are not merely mirror images of each other. Apparently, the functional organization of the human brain is such that the right hemisphere is predominant for both contralateral and ipsilateral sensorimotor functioning. Results are discussed in terms of these theoretical questions and in terms of several methodological considerations necessary for the appropriate study of the functional organization of sensorimotor processes.