Real-Time Neuropsychological Testing of Sensorimotor Cognition During Awake Surgery in Precentral and Postsomatosensory Areas

BACKGROUND: For patients undergoing brain surgery, once primary motor and sensory areas are identified by direct electrical stimulation, resection can be performed in the precentral and postsomatosensory areas while monitoring cognition. For this purpose, we developed a real-time neuropsychological testing (RTNT) protocol tapping sensorimotor cognition. METHODS: We retrospectively reviewed a consecutive series of 57 adult patients with tumors in the precentral and postsomatosensory areas who performed the RTNT sequence. The testing protocol used continuously throughout resection for excisions comprised action verbs, mental rotation of body parts, action imagery, action semantics, ideomotor praxis, and short-term memory. RESULTS: The patients' median performance on RTNT tests was significantly lower for mental rotation and action imagery (chi(2) (2) = 55.98, P < 0.001), as well as their minimum value of patients' performance (chi(2) (2) = 85.048, P < 0.001) and their delta calculated between the patients' performance at the first versus the last RTNT run (chi(2) (2) = 14.33, P < 0.05). Patients showing such decreases in performance on action imagery had lesions overlapping on the right precentral and postcentral gyrus, the supplementary motor area, and the superior and inferior parietal lobe. For the mental rotation task, their maximum lesion overlay included the right cingulum/supplementary motor area and left superior and inferior parietal lobe and medial precuneus. The mean resection extent was 91.15% +/- 17.45 and correlated with the number of motor-related positive sites found by the direct electrical stimulation at cortical (r = -0.279, P = 0.020) and white matter (r = -0.417, P = 0.001) level. CONCLUSIONS: The sensory-motor RTNT is performed to assist surgery in the precentral and postsomatosensory areas.