Heilman and Adams1 detailed the behavioral neurologic sequelae of a young woman with extensive, chronic, mainly right hemispheric injury who had minimal cognitive deficits until undergoing a complete callosotomy for intractable seizures. She subsequently showed left neglect on various tests. The findings appeared to contradict the hypothesis of Kinsbourne,2 who stated that unilateral neglect following focal hemispheric injury involves asymmetric interhemispheric inhibition mediated by the corpus callosum and that callosotomy should ameliorate neglect. Instead, the authors suggested that because neglect appeared only after callosal sectioning and because postoperative structural magnetic resonance imaging (MRI) failed to identify other new tissue injury, the callosal lesion had compromised compensation from the less injured left hemisphere during tests of spatial attention. The evidence provided supports the hypothesis of interhemispheric compensation for unilateral neglect. However, their report could have benefited from some revision.
Mark VW. Callosal Neglect and Cognitive Impersistence. Arch Neurol. 2003;60(10):1493-1494. doi:10.1001/archneur.60.10.1493-a