Intraoperative language mapping can help preserve language postoperatively in patients with large, dominant-hemisphere high-grade gliomas, according to a presentation at the annual meeting of the American Association of Neurological Surgeons.

The presentation centered on one neurosurgeon’s experience with 250 consecutive patients with large, dominant-hemisphere gliomas requiring language mapping.

Intraoperative language mapping involves operating on an awake patient and mapping the anatomy of his or her language function, helping surgeons identify which portions of the tumor are safe to resect.

“Despite considerable evidence supporting the use of intraoperative cortical stimulation to map language function, the efficacy of this technique in preserving functional neurological outcome following aggressive glioma resection remains poorly understood,” said Nader Sanai, MD, the study presenter.

Overall, 159 of 250 patients 63.6 percent) had intact speech preoperatively. At one week postoperatively, 194 (77.6 percent) remained at baseline language function, whereas 21 (8.4 percent) worsened and 35 (14.0 percent) had new speech deficits.

By six months, 52 (92.8 percent) of 56 patients with new or worsened language deficits returned to baseline or better; the remaining four patients (7.1 percent) had permanent deficits. Thus, 1.6 percent of all patients developed permanent postoperative language deficits.

“This series of patients represents the largest study to date examining intraoperative language mapping for gliomas, and supports the use of language mapping as the rule, rather than the exception, for dominant hemisphere gliomas,” stated Sanai. “The findings support the conclusion that cortical language mapping may be used as a safe and efficient adjunct to optimize glioma resection while preserving essential language sites.”