Abstract
An 18-year-old left-handed female with a large left hemisphere arteriovenous malformation in the frontoparietal region underwent brain mapping of the somatosensory cortex using a whole-head neuromagnetometer. Results indicated the presence of two complete somatosensory maps in the unaffected, right hemisphere. A map of contralateral body surface areas was found in the expected location in the anterior parietal lobe. A second map of ipsilateral body surface areas was found inferior to the first, extending from the inferior parietal lobe into peri-insular cortex, including SII. A less topographically organized map of the right side of the body was also found in the left hemisphere. Evoked magnetic flux components associated with right-sided stimulation occurred earlier, were more numerous, and were stronger in the ipsilateral as compared to the contralateral hemisphere, suggesting that the ipsilateral map is functional. These findings are discussed in relationship to other functional imaging studies of reorganization of the functional cortex in response to early trauma or congenital anomaly.