Trigeminal Neuralgia, also known as tic douloureux, is a disorder abnormality of the fifth cranial nerve, called the trigeminal nerve, which is the largest of the nerves coming directly from the brain. There are two trigeminal nerves, one on each side of the face. The Trigeminal Nerve is the one responsible primarily for sensation to the face and the muscles of chewing. This nerve leaves the brain stem and travels through a tunnel in the skull called Meckels cave. There, at the ganglion it splits into three “arms”, the ophthalmic (to the eye, forehead and nose), the maxillary (cheek) and the mandibular (jaw).
TN is characterized by sudden, severe, one sided, "stabbing" or "shock like" facial pain. In 95% of people it appears on only one side of the face. Each pain is short and can be precipitated by a trigger – like a light touch to a certain area of the face. This pain can occur almost anywhere between the jaw and forehead, including inside the mouth. However, it usually is limited to one side of the face.
About 5 out of every one 100,000 people are diagnosed each year with TN - 1,500 in Canada. It is slightly more common in females, and usually affects patients in their fifties. Although infants, children and young adults may develop this disorder, it is rare in people younger than age 40.The pain comes in quick electrical bursts lasting only seconds to minutes. Such episodes occur in bouts lasting days to weeks and are followed by remissions lasting weeks to years. The pain can be triggered by common activities such as chewing, shaving, talking, and yawning. The face often has one or more sensitive points that trigger the pain. Even a light breeze can cause severe pain.
The pain will normally occur on only one side of the face, most commonly on the right. Occasionally the pain will occur on both sides of the face and when this happens the attacks to each side appear at different times. The painful attacks of TN can involve one or more branches of the trigeminal nerve. Most commonly the middle branch or the lower branch either individually or in combination with each other are involved. The area of the nerve branch involvement determines the type of symptoms the patient will have. Since the largest percentages of patients have involvement of the middle and lower branches many of the initial symptoms are felt in the teeth and gums.
The diagnosis is made on history (the description of the pain) and the neurological examination is normal.
Causes | Treatment | Surgery | Secondary TN | Post Herpetic Neuropathy | Anesthesia Dolorosa |Balloon Compression Rhizotomy
It is believed that TN is caused by irritation of the Trigeminal nerve by a blood vessel sitting on its origin from the brain. It can also result from the loss of the nerve’s protective covering in diseases like MS or from the pressure of a tumor on the nerve.
Patients are usually treated first with drugs. The ones used are anti-seizure drugs and it is believed that these drugs alter the way the brain transmits pain signals. Drugs include:
Carbamazepine (Tegretal)
Oxcarbazepine (Trileptal)
Gabapentin (Neurontin)
Phenytoin (Dilantin)
Baclofen
If the drugs are ineffective or if the side effects become bothersome, then surgery is an option. Surgical options can be classified in one of two ways: Nerve preserving or nerve damaging.
The Microvascular Decompression or MVD involves opening the skull and exposing the nerve. The surgeon locates the blood vessels near the nerve and places Teflon padding between the nerve and blood vessel. The MVD has a success rate of 85-90%. After 15 – 20 years about half the patients will have the return of some pain.
This is major surgery and the risks include death (up to 1% in some reports), stroke, hearing loss, facial nerve weakness, meningitis, cerebral spinal fluid leaks, and seizures.
Patients must remain in the hospital for 3 to 5 days and recovery can take about 2 months.
are those that are done through the skin. The surgeon slides a needle into the skull base so that the tip lies near the Trigeminal nerve’s ganglion.
In all these percutaneous procedures there is an 85% early success rate but within 5 years about half of the patients will have pain return. These procedures can be repeated.
The risks include meningitis, some difficulty chewing, a cheek hematoma, double vision, loss of the corneal reflex, anesthesia dolorosa, a sudden rise or drop in blood pressure, cerebrospinal fluid leaks and meningitis. Only 5% .of patients will experience any complication.
There are several machines used. All provide focused radiation to a small point near the nerve’s origin from the brainstem. The nerve is damaged using radiation.
Gamma Knife – uses cobalt radiation and is the machine used in Winnipeg (soon to be in Toronto and Sherbrooke)
Modified LINAC – this is machine currently used in Calgary, Vancouver, Toronto, Ottawa, Halifax, Montreal
Novalis – currently only Canadian site is Calgary. With this machine the size and shape of the beam can be adjusted to achieve an optimal homogeneous or modulated dose of radiation.
The compression of the nerve is caused by a tumor or a vascular abnormality. It occurs in less than 2% of TN. The pain is slightly different with some associated sensory changes, numbness or weakness.
The pain may be more throbbing and burning than the electrical shock like pains of typical TN and associated with significant facial trauma or reconstructive surgery.
The pain follows an attack of shingles. People describe it as a crawling, prickling and burning sensation.
A complication of the surgeries for TN. Patients experience a combination of numbness and burning pain. It is very difficult to treat.
Medications are the first treatment usually prescribed for Trigeminal Neuralgia. In many patients the disease can be treated for years using the various drugs available. However, for those patients who are unable to control the pain with drugs alone or for whom the side effects of the drugs becomes intolerable there are surgical options available.
One of these options is the “Percutaneous Balloon Compression Rhizotomy.” This is a procedure during which the Trigeminal nerve root is damaged by compression with a balloon at the end of a needle. The term “Rhizotomy” actually means to damage a nerve root. The “Percutaneous” means through the skin.
With the patient under a general anesthetic, a needle is passed through the cheek into the skull so that its tip lies along the Trigeminal Nerve. A small catheter with a balloon at the end is passed through the needle and the balloon inflated for a minute or two to cause an injury to the nerve. The neurosurgeon uses X-rays and/or a fluoroscope to ensure the needle and catheter are in the correct place.
This procedure is a good option for those patients who are hesitant to undergo a craniotomy and MVD procedure either because they are reluctant to have major surgery or they have another health problem making surgery too dangerous.
About 90-95% of patients will find that the TN pain disappears immediately after the balloon procedure although for some patients it may take a day or so for the pain to go away completely. The pain free period varies from person to person, but half the people will still be pain free after 5-8 years. This procedure can be repeated if necessary.
Most patients will experience some degree of facial numbness post operatively. This will decrease over time. The numbness indicates the nerve has been damaged which is the aim of the surgery.
There may be some weakness in the chewing muscles after the surgery. This is usually temporary and will resolve over the first few weeks.
A small percentage of patients (up to 5%) may experience some complication. These complications include meningitis, some difficulty chewing, a cheek hematoma, double vision, loss of the corneal reflex, anesthesia dolorosa, a sudden rise or drop in blood pressure, cerebrospinal fluid leaks and meningitis and an outbreak of cold sores.
Pre-op
The anesthetist and neurosurgeon will likely order some blood tests, a chest X-ray, ECG and in some instances an MRI.
You may be advised to stop taking any aspirin for 2 weeks prior to the surgery to help prevent bleeding.
Post-op
You will be given a schedule for the withdrawal of any drugs you are taking for TN. Follow this schedule closely as drugs such as Tegretal should not be stopped abruptly.
Ice packs against the cheek will decrease bruising and swelling
Report any of the following symptoms to your doctor immediately:
Headache not relieved with Tylenol
Fever
Stiff neck
Drainage of clear fluid from the nose or down the back of your throat
Chest pain or shortness of breath
You should be able to resume your normal activities within a week
All material contained on this site is provided for information only and is not to be considered medical advice or direction.
home contact webmaster message forum
Web site revised November 2004