Gamma Knife Trigeminal Neuralgia Radiosurgery

Trigeminal neuralgia, also known as tic douloureux, is a neuropathic disorder caused by the compression of one or both of the patient’s trigeminal nerves. The trigeminal nerve is the fifth cranial nerve and it is commonly referred to as “the fifth nerve” or simply “V”. It is responsible for the perception of sensation in the face, and while it is primarily a sensory nerve, it is also involved in certain motor functions like chewing and swallowing. Studies have estimated that approximately 1 in 15,000 people suffer from trigeminal neuralgia. The disease tends to occur with greater frequency in patients who are 50 years or older, and it tends to be more common amongst elderly females. However there have been cases of trigeminal neuralgia in younger patients, some as young as three years of age.

The symptoms associated with trigeminal neuralgia are sharp, intensely mind-numbing shock-like stabs of pain in the face. These can occur separately or at once in different areas, like the ear, eye, nose, lips, forehead, scalp, teeth and side of the face. The pain usually occurs in one side of the face, depending on which trigeminal nerve is affected. However, there are some cases in which both of the patient’s trigeminal nerves are affected, resulting in bilateral pain. Pain can be triggered by interior or exterior stimuli. Even something as small as a chewing motion or a light finger’s touch against the cheek can trigger an episode of intense pain in an affected patient. At times, however, episodes of pain can occur without any apparent trigger.

The pain can last for a few seconds, a few minutes or several hours. Loud noises and large crowds, talking, chewing, and even (in the worst cases) the making of facial expressions can aggravate the condition. Numbness is not usually associated with trigeminal neuralgia unless there is co-existing multiple sclerosis. Pain associated with trigeminal neuralgia occurs in cycles, and often there may be spontaneous remissions from pain lasting weeks to years. Interestingly, this pain usually responds to carbamazepine (Tegretol), an oral anticonvulsant medication.

Trigeminal neuralgia is usually caused by compression of the sensory (trigeminal) nerve within the skull by a small artery or vein at the point where the nerve joins the brain stem. Sometimes a small, benign tumor compresses the nerve, causing jolts of electrical shock-like pain to radiate into the face. A small percentage of trigeminal neuralgia patients also suffer from multiple sclerosis. In this case the inflammatory response affecting the brain also involves the trigeminal nerve, causing paroxysmal pain.

Tic douloureaux is unique among pain disorders because nearly all treatments work for a period of time. Over the years, peripheral nerve avulsion, heating, cooling, compressing, decompressing, chemical ablation, and irradiation have all enjoyed varying degrees of success. Because of the effectiveness of carbamazepine (Tegretol), its use is usually the first level of treatment. Other anticonvulsants may be tried, but these are not usually as effective. When oral medication fails to control this dreadful pain, surgical measures must be taken. Among these, terminal neuralgia radiosurgery has proven to be especially effective and safe.

With the use of the Gamma Knife, trigeminal neuralgia can be successfully treated without the need for surgical incisions that might result in further complications. A single, non-invasive morning treatment has resulted in excellent pain relief in 58% of cases, good pain relief in 36% and failed pain relief in 6%. Transient facial numbness is rare. Long term recurrence rates are unknown. This treatment is a suitable alternative to anticonvulsant therapy and compares favorably to other treatments. Trigeminal neuralgia radiosurgery is an especially preferable treatment option for patients who are medically unfit for the use of general anesthetic.