Brain surgery treats problems in the brain and the structures around it through an opening (craniotomy) in the skull (cranium).

The hair on part of the scalp is shaved. The scalp is cleansed and prepared for surgery. An incision is made through the scalp. The incision may be made behind the hairline and in front of your ear, at the hairline near your neck, or elsewhere, based on where the problem in your brain is located.

• The scalp is pulled up. A hole is created in the skull. A piece of the skull (a bone flap) is removed. Most of the time, this flap will be placed back after the surgery is over.
• Through this hole, your surgeon may clip off an aneurysm to cut off the blood flow, biopsy or remove a tumor, remove an abnormal part of your brain, or drain blood or an infection.
• Your surgeon may use a special microscope to perform the procedure. Monitors to check pressure may also be used.
• If possible, the surgeon will make a smaller hole and insert a tube with a light and camera on the end (endoscope). The surgery will be done with tools placed through the endoscope.

The surgeon may use computers to help find the exact spot that needs to be treated (MRI or CT scans).

The bone is usually replaced and secured in place using small metal plates, sutures, or wires. The bone flap may not be put back if your surgery involved a tumor or an infection, or if the brain was swollen. (This is called a craniectomy.)

The time it takes for the surgery varies based on the type of problem that is being treated.

Brain surgery may be needed to treat or remove:

• Brain tumors
• Bleeding (hemorrhage) or blood clots (hematomas) from injuries (subdural hematoma or epidural hematomas)
• Weaknesses in blood vessels (cerebral aneurysms) See also: Brain aneurysm repair
• Abnormal blood vessels (arteriovenous malformations; AVM)
• Damage to tissues covering the brain (dura)
• Infections in the brain (brain abscesses)
• Severe nerve or facial pain (such as trigeminal neuralgia or tic douloureux)
• Skull fractures
• Pressure in the brain after an injury or stroke
• Some forms of seizure disorders (epilepsy)
• Certain brain diseases (such as Parkinson’s disease) that may be helped with an implanted electronic device