Anesthesia for functional neurosurgery: review of complications

The use of functional stereotactic neurosurgery is increasing for treatment of patients with movement disorders and other chronic illnesses. The anesthetic considerations include the influence of the anesthetic agents on the microelectrode recordings and stimulation testing of an awake patient. The purpose of this study was to review the anesthetic management and incidences of intraoperative complications during functional neurosurgery in our institution. One hundred seventy-eight patients underwent an ablative procedure (n = 6) or the insertion of deep brain stimulator (n = 172) under monitored anesthesia care for movement disorders (n = 124), chronic pain (n = 20), and other procedures (n = 34). Local anesthetic was used for head frame pin sites and burr holes. No sedation/analgesia was administered to 57 (32%) patients. One patient required conscious sedation and another general anesthesia for the entire procedure. The remainder received small increments (mean +/- SD) of propofol (113 +/- 73 mg), midazolam (1.6 +/- 0.8 mg), and/or fentanyl (93 +/- 55 mug). Intraoperative complications that occurred in 16% of the patients included seizures (n = 8), change in neurologic status (n = 5), airway obstruction (n = 2), and hypertension (n = 7). Functional neurosurgery can be performed with minimal anesthesia in many patients. Awareness and vigilance can improve the identification and early treatment of intraoperative complications such as seizures, loss of airway, and changes in the neurologic status.