http://articles.mercola.com/sites/articles/archive/2020/03/12/awake-during-brain-surgery.aspx
Story at-a-glance –- Awake brain surgery is typically performed to treat epileptic seizures or remove tumors without clear borders that have spread throughout the brain
- Because the tumors are often close to brain regions responsible for controlling vision, language and movement, it would be too dangerous to attempt to remove them while the patient is completely under anesthesia,