Indications and limits of intraoperative cortico-subcortical mapping in brain tumor surgery: an analysis of 101 consecutive cases.

AIM: Here we report our recent experience in supratentorial cortico-subcortical stimulation mapping during surgery for cerebral lesions closely related to sensorimotor and language areas.

METHODS: We retrospectively analyzed clinical data of 101 consecutive patients operated on with the aid of electrical stimulation mapping (ESM). Patients harbored a mass lesion situated in or near language (Group A, 30 patients) and sensorimotor (Group B, 71 patients) areas.

RESULTS: A macroscopically complete removal of the tumor was carried out in 22 cases out of 28 of group A and in 57 out of 73 of group B. In the first group there was one postoperative death due to a pulmonary embolism. At a mean follow-up of 24.3 months, 15 patients are still alive, 12 out of them are recurrence free and hold a useful language function, while the other 12 patients had a mean survival time of 19.3 months, with a mean high quality survival period (KPS?70) of 17.8 months. In the second group there was no postoperative death. At a mean follow-up of 24.8 months, 55 patients are alive and 47 maintain a useful motor function. Eighteen patients died for tumor progression, with a mean survival time of 18.7 months. Their median high-quality survival period (KPS ? 70), with preservation of a useful motor function, was 16.5 months.

CONCLUSION: When properly indicated and correctly carried out, ESM for language and motor functions allows to enhance resection of lesions in eloquent areas with a surgical permanent morbidity comparable to that for lesion in non eloquent areas.