Awake craniotomy sounds like something from a horror film. The patient’s skull is opened, the brain exposed, and the surgeon begins removing tissue — while the patient is awake and talking.
It is also, in specific circumstances, the safest way to operate.
Why the brain has no pain receptors
The brain itself cannot feel pain. It processes pain signals from the rest of the body, but it has no nociceptors — the receptors that detect tissue damage. This is why awake brain surgery is possible: once the scalp and skull are anaesthetised (which does require local anaesthetic and sedation), the patient can be brought to full consciousness without experiencing pain from the brain being touched.
What the patient does feel is pressure, vibration, and — most importantly from the surgeon’s perspective — the effects of having specific areas stimulated or removed.
The reason for keeping patients awake
The brain’s functional organisation varies considerably between individuals. The areas responsible for speech, language processing, and motor control don’t sit in exactly the same location in every person. Preoperative imaging gives a map, but it’s not reliable enough to use alone when operating millimetres from a region that controls someone’s ability to speak.
The solution is direct cortical stimulation. The surgeon uses a small electrode to briefly disrupt activity in specific patches of cortex, while the patient performs tasks — naming objects, counting, reading words. If stimulating a particular area causes the patient to stop mid-sentence or produce the wrong word, that area is marked as eloquent cortex and left untouched. The surgery routes around it.
This method, developed significantly by George Ojemann in the 1980s, has allowed surgeons to remove tumours that would previously have been considered inoperable due to their proximity to speech areas.
What patients experience
Patients are prepared extensively in advance — they know exactly what to expect, rehearse the tasks they’ll be asked to perform, and are sedated for the portions of surgery that don’t require their input. Most report the experience as surreal but not painful. There are documented cases of patients playing the guitar, speaking multiple languages, and solving maths problems during surgery — partly for assessment, partly because ongoing engagement with the brain’s functions helps the team monitor in real time.