Contralateral and ipsilateral tactile extinction in patients with right and left focal brain damage.

Heilman has suggested that right hemisphere lesions produce neglect both in the spaces contralateral and ipsilateral to the damaged hemisphere. To test this hypothesis, we studied the incidence of contralateral and ipsilateral tactile extinctions in 44 right and 59 left brain-damaged patients, by means of a standard test of a double tactile simultaneous stimulation of symmetrical and asymmetrical parts of the two sides of the body and of ipsilateral body parts. Results did not confirm Heilman's hypothesis; while contralateral tactile extinction was more frequent and severe in right than in left brain-damaged patients, no hemispheric difference was found when the number of ipsilateral extinctions was taken into account. Furthermore, ipsilateral tactile extinction was significantly related to aspecific factors (such as age, severity of sensorimotor impairment and widespread mental deterioration), irrespective of the hemispheric side of lesion.