Used to relieve pressure on the cranial nerves by moving or isolating blood vessels that are impacting and irritating those nerves, microvascular decompression is an effective treatment for those patients suffering from hemifacial spasms (a neuromuscular disorder that results in muscles on one side of the face twitching in an involuntary manner due to nerve irritation) as well as trigeminal neuralgia (severe facial pain from irritation of the trigeminal nerve).
After being given general anesthesia and having their head secured to prevent movement during surgery, a surgeon makes an incision behind the ear and moves away the skin to access the skull and dura membrane covering the brain. Moving aside tissue and reaching the affected cranial nerve (in the case of hemifacial spasms, the seventh cranial nerve specifically), any blood vessels impacting the nerve are separated and a barrier (a small pad) is placed between the nerve and the blood vessel to prevent any further contact. All tissues, bone and skin are then replaced to their normal position and any incisions are sealed.
Post-surgery the patient is moved to a recovery unit, and is usually discharged within two days. Relief from the symptoms of hemifacial spasms should be immediate, however mild twitching can remain for a few weeks.