Awake craniotomy for brain tumor: indications, technique and benefits

Abstract

Increasing interest in the quality of life of patients after treatment of brain tumors has led to the exploration of methods that can improve intraoperative assessment of neurological status to avoid neurological deficits. The only method that can provide assessment of all eloquent areas of cerebral cortex and white matter is brain mapping during awake craniotomy. This method helps ensure that the quality of life and the neuro-oncological result of treatment are not compromised. Apart from the medical aspects of awake surgery, its economic issues are also favorable. Here, we review the main aspects of awake brain tumor surgery. Neurosurgical, neuropsychological, neurophysiological and anesthetic issues are briefly discussed.

Keywords::

• awake
• brain
• craniotomy
• mapping
• tumor

Financial & competing interests disclosure

M Bernstein is affiliated with the Greg Wilkins-Barrick Chair Medical Student Scholarship in International Surgery. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Having the patient awake during mapping for surgical resection of intra-axial tumors, especially in eloquent areas, is superior in terms of the extent of resection and postoperative neurological status, as compared to resections under general anesthesia.

• Generally, any supratentorial intra-axial mass lesion located under eloquent cortex is considered for this procedure. Not only motor or language cortex but also the cortex responsible for all functions that we can examine is taken as the eloquent cortex.

• During awake craniotomies, patients may be awake throughout the whole procedure (awake–awake–awake procedure) or sedated during the most unpleasant part of the operation and awake for intraoperative testing (asleep–awake–asleep).

• Bipolar stimulation using a probe with two tips separated by 6–10 mm and a 100-μs square wave pulse with a 50-Hz repetition rate is usually used.

• Stimulation of motor cortex may produce involuntary movement or a disturbance of movement that the patient is asked to perform.

• By assessing speech, errors such as anomia (inability to name objects with preserved ability to talk), speech arrest (inability to say anything after an image is shown and stimulation applied) and many others can be examined.

• Seizures and lack of cooperation during testing are two of the most common neurosurgical complications of brain mapping, but with good selection, both are uncommon.

• Patients who undergo awake craniotomy require a shorter stay in the postanesthesia care unit and in the hospital in total.

• Patient satisfaction with the procedure is high.