Surgery of astrocytomas in the motor and premotor cortex under local anesthesia: report of 11 cases.

Under local anesthesia, gliomas of the premotor and primary motor cortex can be surgically removed with minimal morbidity. However, since these neoplasms exhibit an infiltrative growth pattern towards the pyramidal tract and are frequently not well delineated from functional motor cortex, the long-term outcome is unfavorable. In this series, 5 of 11 patients presented with a recurrent tumor within two years of operation. Two of these patients with recurrent tumors initially had a low grade glioma and three an anaplastic glioma. Due to the longer progression-free interval after surgery and the unpredictable course of patients with low grade gliomas, all efforts should be undertaken to achieve safe and radical resection with the use of intraoperative mapping and monitoring techniques as well as cryo-cut examinations at all tumor border zones to prove radicality. Since malignant tumors are known to recur in most instances, radical resection is justified only in functionally safe areas.