General Versus Local Anesthesia for Deep Brain Stimulator Insertion
One hundred years ago, in the midst of the carnage of World War I, there was a consensus among the surgeons like Harvey Cushing operating on the frontline, soldiers with traumatic brain injuries that the operative conditions and outcomes were much improved when they conducted craniotomies relying on cocaine infiltration of the scalp instead of a chloroform or ether anesthetic. He coined the term regional anesthesia to differentiate it from; the usual injection of local anesthetics into the surgical wound. With the growth of our anesthetic pharmacological arsenal, controlled ventilation and monitoring, general anesthesia has become a much safer and comfortable option for patients having intracranial procedures. One would presume that with these developments awake brain procedures would be rendered obsolete. Eloquent brain structures, however at risk during tumor resection have compelled neurosurgeons to return to the practice of “awake craniotomy” (a short period of general anesthesia followed by and awake patient under regional anesthesia) to assure their patients the best possible outcome. After a century now, both techniques are still alive and well.
Not too long ago, the controversy between general and regional/local anesthesia reached a peak in the 1980s in the management of carotid endarterectomies. After multiple studies and no definitive difference in outcome for patients, the controversy died with practitioners opting for the technique they are most comfortable with.
It appears that a similar controversy is developing regarding the management of deep brain stimulators. This not so new technique is the last approach in the treatment of movement disorders and represents the best option for some of these unfortunate patients. Implantation of microelectrodes in the brain represents a challenge for the neurosurgeon, the anesthesiologist and more importantly the patient. When first described, the implantation of the electrodes was done under local anesthesia with almost continuous and complex clinical neurological examinations following implantation. This procedure while beneficial in ensuring optimal placement of the electrode is long and tedious and the patients while painless at the surgical site are uncomfortable, usually complaining of staying still on the hard operating room table. Progress in brain imaging and intraoperative micro electrode recording allow now a greater precision in the implantation of these electrodes under general anesthesia. Furthermore, the judicious use of a light anesthetic providing little interference with recordings has provided practitioners an opportunity to reconsider general anesthesia for these procedures. Finally, general anesthesia with a protected airway from the point of view of the practitioner ensures safety while precluding anxiety and discomfort for the patient.
However, no definitive outcome study has been done at this time to define which anesthetic technique: local or general will facilitate the best results for patients. In an effort to understand the whys and why nots of either anesthetic technique, we asked Drs. Venktraghavan and Sheshadri to explain why they are so attracted to the general anesthesia approach, while Drs. Athiraman and Rich will argue for their commitment to a continuous clinical examination under local anesthesia.