Surgery for brain tumors involves general anesthesia which means the patient is completely asleep for the entire procedure. In some cases, the patient will be woken up during the surgery for monitoring the area of the brain that is being operated on. If the surgeon gets close to the part of the brain that controls speech, he or she will notice a deficit in the patient’s speech. Similarly, movement in an arm or leg will be detected earlier if the surgeon is getting close to a part of the brain controlling that movement.
In order to perform a surgery, an incision is made on the scalp. Very little hair is shaved (more or less the thickness of the size of a pencil) in the vast majority of cases. Once the incision is made, the surgeon gets down to the bone, creating a window that gives him access to the brain. The surgeon resects as much of the tumor safely without damaging the surrounding brain.
After the resection, the bone is placed back on the head and is secured in place with titanium plates and screws. These screws stay in forever, they don't set off metal detectors, and they still allow the patient to get an MRI afterwards. On the skin, the surgeon closes with absorbable sutures that would simply fall out over the course of a few weeks post surgery.
The tumor may be approached in a variety of different ways, depending on the size, location and type. This includes surgical resection, an open or needle biopsy or radiosurgery which includes tools like Gamma Knife, which involves delivering stereotactic radiation to a tumor. The benefits of Gamma Knife radiation is that it does not involve making an incision, it can usually be completed under an hour and the patient gets to go home that same day.