Trigeminal Neuralgia Overview:
Trigeminal neuralgia (TN) also known as also known as “tic douloureux” is a chronic pain condition that affects the trigeminal nerve, which carries sensation from your face to your brain. Trigeminal neuralgia is a stabbing pain in the face. Trigeminal neuralgia affects women more often than men, and it’s more likely to occur in people who are older than 50.
Trigeminal neuralgia is a disorder of the fifth cranial (trigeminal) nerve. The typical or “classic” form of the disorder known as TN1 causes extreme, sporadic, sudden burning or shock-like facial pain in the areas of the face where the branches of the nerve are distributed – lips, eyes, nose, scalp, forehead, upper jaw, and lower jaw. The pain episodes last from a few seconds to as long as two minutes. These attacks can occur in quick succession, in volleys lasting as long as two hours. The “atypical” form of the disorder known as TN2, is characterized by constant aching, burning, stabbing pain of somewhat lower intensity than TN1. Both forms of pain may occur in the same person, sometimes at the same time.
TN occurs most often in people over age 50, although it can occur at any age, including infancy. The incidence of newly diagnosed cases of TN in the United States population averages approximately 4.3 per 100,000 individuals (per year) and the average for women is slightly higher than for men. If people have TN for an average of 8 years, then a rough estimate of prevalence in United States is 108,000. The definition of a rare disease in the United States is one that affects fewer than 200,000 at any one time. Thus, TN is a rare disease.
The Trigeminal Nerve:
The trigeminal nerve is one of 12 pairs of nerves that are attached to the brain. The nerve has three branches that conduct sensations from the upper, middle, and lower portions of the face, as well as the oral cavity, to the brain. More than one nerve branch can be affected by the disorder. Rarely, both sides of the face may be affected at different times in an individual, or even more rarely at the same time which is known as bilateral TN.
The trigeminal nerve is the fifth of 12 pairs of cranial nerves in the head. It is the nerve responsible for providing sensation to the face. One trigeminal nerve runs to the right side of the head, while the other runs to the left. Each of these nerves has three distinct branches. After the trigeminal nerve leaves the brain and travels inside the skull, it divides into three smaller branches, controlling sensations throughout the face:
- The first branch controls sensation in a person’s eye, upper eyelid and forehead.
- The second branch controls sensation in the lower eyelid, cheek, nostril, upper lip and upper gum.
- The third branch controls sensations in the jaw, lower lip, lower gum and some of the muscles used for chewing.
What Causes Trigeminal Neuralgia?
The pain associated with trigeminal neuralgia represents an irritation of the nerve. The cause of the pain usually is due to contact between a healthy artery or vein and the trigeminal nerve at the base of the brain. This places pressure on the nerve as it enters the brain and causes the nerve to misfire.
Other causes of trigeminal neuralgia include pressure of a tumor on the nerve or multiple sclerosis, which damages the myelin sheaths that insulate and help conduct electrical impulses across nerve cells. Development of trigeminal neuralgia in a young adult suggests the possibility of multiple sclerosis.
Types of Trigeminal Neuralgia:
- Classic Trigeminal Neuralgia, type 1, (TN1): (also known as tic douloureux) facial pain of spontaneous onset with greater than 50% limited to the duration of an episode of pain (temporary pain). TN is often caused by loss of or damage to the nerve’s protective coating, (myelin). The most widely accepted view is that myelin damage results from irritation of the nerve, usually a blood vessel that causes the nerve to be compressed.
- Trigeminal Neuralgia, Type 2, (TN2): facial pain of spontaneous onset with greater than 50% as a constant pain.
- Secondary Symptomatic Trigeminal Neuralgia (STN): Pain resulting from multiple sclerosis.
- Post- Herpetic Neuralgia (PHN): pain resulting from herpes zoster outbreak (SHINGLES) along the trigeminal nerve.
- Trigeminal Neuropathic Pain (TNP): facial pain resulting from unintentional injury to the trigeminal system from facial trauma, oral surgery, ear, nose and throat (ENT) surgery, root injury from posterior fossa or skull base surgery, stroke, etc. This pain is described as dull, burning, or boring and is usually constant because the injured nerve spontaneously sends impulses to the brain. The injured nerve is also hypersensitive to stimulation, so attacks of sharp pain can also be present. The area which is sensitive to touch and triggers these sharp attacks is the same area where the pain occurs. Numbness and tingling are also signs of a damaged nerve.
- Trigeminal Deafferentation Pain (TDP): facial pain in a region of trigeminal numbness resulting from intentional injury to the trigeminal system from neurectomy, gangliolsys, rhizotomy, nucleotomy, tractotomy, or other denervating procedures. Despite the loss of sensation, constant pain is felt in the numb area(s), which varies in intensity and can include sensations of burning, crawling, tingling, boring, stinging, and/or unpleasant aching.
Trigeminal Neuralgia and Multiple Sclerosis:
Approximately 2-4% of people with MS develop trigeminal neuralgia and with MS statistically about 18% of the condition is likely to be the bilateral form. usually the condition begins on one side of the face and after years begins to occur on the other. Trigeminal neuralgia with MS is more likely to be a dull, burning and more constant pain than the more electrical bolt type pain.
It can occur as an initial symptom of MS. While it can be confused with dental pain, this pain is neuropathic (caused by damage to the trigeminal nerve) in origin.
The main symptom of trigeminal neuralgia is sudden attacks of severe, sharp and shooting facial pain that last from a few seconds to about two minutes.
The pain is often described as an excruciating sensation, similar to an electric shock. The attacks can be so severe that you are unable to do anything during them, and the pain can sometimes bring you to your knees.
Trigeminal neuralgia usually only affects one side of your face. In rare cases it can affect both sides, although not at the same time. The pain can be in the teeth, the lower jaw, upper jaw, cheek and, less commonly, in the forehead or the eye.
You may feel aware of an impending attack of pain, though these usually come unexpectedly.
After the main, severe pain has subsided, you may experience a slight ache or burning feeling. There may also be a constant throbbing, aching or burning sensation between attacks.
You may have episodes of pain lasting regularly for days, weeks or months at a time. It is possible for the pain to then disappear completely and not recur for several months or years (a period known as “remission”). However, in severe cases, attacks may occur hundreds of times a day, and there may be no periods of remission.
Attacks of trigeminal neuralgia can be triggered by certain actions or movements, such as:
- brushing your teeth
- washing your face
- a light touch
- shaving or putting on make-up
- a cool breeze or air conditioning
- head movements
- vibrations, such as walking or a car journey
However, pain can occur spontaneously with no triggers whatsoever.
Magnetic resonance imaging (MRI) can detect if a tumor or multiple sclerosis is irritating the trigeminal nerve. However, unless a tumor or multiple sclerosis is the cause, imaging of the brain will seldom reveal the precise reason why the nerve is being irritated. The vessel next to the nerve root is difficult to see even on a high-quality MRI. Tests can help rule out other causes of facial disorders. Trigeminal neuralgia usually is diagnosed based on the description of the symptoms provided by the patient.
Treatment with Medications:
Anticonvulsant medications, which slow down the nerve’s conduction of pain signals, are usually the first treatment option.
Tegretol, Trileptal, Carbatrol, Dilantin, Lamictal, Keppra, Topamax, Neurontin, Klonopin and Lyrica
- Carbamazepine (Tegretol)
- Oxcarbazepine (Trileptal)
- Gabapentin (Neurontin)
- Phenytoin (Dilantin, Phenytek)
- Topiramate (Topamax)
- Lamotrigine (Lamictal, Lamictal ODT, Lamictal XR)
- Pregabalin (Lyrica)
- Baclofen (Lioresal, Gablofen)
Tegretol (carbamazepine) is the primary drug used to treat TN. Many physicians believe that the relief of facial pain with Tegretol confirms the diagnosis of TN.
The Microvascular Decompression (MVD), which was designed to cause no additional nerve damage, is the most invasive of all surgical options to treat TN, but it also offers the lowest probability that the pain will return. This procedure requires a small opening be made behind the ear. While viewing the trigeminal nerve through a microscope, the surgeon places a soft cushion between the nerve and the offending blood vessels.
Balloon Compression is an outpatient procedure, although sometimes the patient is kept overnight. It is performed in the operating room, with the patient receiving general anesthesia. In this percutaneous procedure, a cannula is inserted through a puncture in the cheek and guided to a natural opening in the base of the skull. A soft catheter with a balloon tip is threaded through the cannula. The balloon is inflated, squeezing the nerve against the edge of the dura and the petrous bone. Balloon compression works by selectively injuring nerves which mediate light touch.
Glycerol Injection is also an outpatient or overnight procedure. It is performed with intravenous sedation. A thin needle is introduced through a puncture in the cheek, next to the mouth and guided through a natural opening in the base of the skull. Just inside this opening is the trigeminal ganglion where all three nerves come together. Glycerol bathes the ganglion and affects the demyelinated fibers.
Radiofrequency lesioning is usually performed in an outpatient setting. The patient is sedated for a few minutes while a needle is passed though the cheek, up thorough a natural opening in the base of the skull. The patient is awakened and a small electric current is passed through the needled causing tingling. When the needle is positioned so the tingling occurs in the same area of TN pain, the patient is sedated again and a radiofrequency current is passed through the needle to intentionally destroy part of the nerve.
Radiosurgery (GammaKnife, CyberKnife, etc.) is a non-invasive procedure performed on an outpatient basis; it requires no incision but may require the attachment of a head frame. Highly focused beams of radiation are directed to the area where the trigeminal nerve exits the brainstem. The radiation causes the slow formation of a lesion on the nerve that disrupts the transmission of pain signals to the brain. However, pain relief from this procedure may take several months.
Complementary and Alternative Medications (CAM)
As in traditional medical treatments, the effectiveness of all CAM treatments depends on several things, including the person’s state of health, and the skill and knowledge of the practitioner. Every person responds differently to treatments, and even though most of these remedies are non-invasive, they still may have potential risk and complications.
- Nutritional therapy
- Electrical Nerve Stimulation
- TENS (Transcutaneous Electrical Nerve Stimulation)
- Upper cervical chiropractic
- Vitamin B-12 Injections
- Vitamin Therapy
Living with trigeminal neuralgia can be extremely difficult, and your quality of life can be significantly affected.
You may feel like avoiding activities such as washing, shaving or eating to avoid triggering pain, and the fear of pain may mean you avoid social activities. However, it’s important to try to live a normal life, and be aware that becoming undernourished or dehydrated can make the pain far worse.
The emotional strain of living with repeated episodes of pain can lead to psychological problems, such as depression.
During periods of extreme pain, some people may even consider suicide and at these times you should contact your local emergency services or get to a hospital.
Even when pain-free, you may live in fear of the pain returning. It is imperative that you do not succumb to these impacts and seek both solutions to trigeminal neuralgia and support from friends, family, clinicians and / or support groups.
Research & Tidbits:
- Research is being done to try to stop damage to the myelin sheath, or to help regeneration after the damage is done by utilizing medications, nutrition, and gene therapy.
- A study of MS patients with loss of facial sensation was printed in Archives of Neurology, Jan 2001. In 5 patients, unique lesions were found on the trigeminal nerve root. Similar lesions have been seen during animal studies with Herpes Simplex Virus (HSV), and continued study will be needed to determine the significance—whether a HSV infection causes these lesions, or whether a disease related inflammatory response triggers the HSV.
- An incidence of face pain and MS due to a rare headache disorder, Trigeminal autonomic cephalgia’s (TAC’s), was reported in Cephalalgia, 2004 by R. Dave and A. Al-Din. The pain, which was reported to be shooting, stabbing, piercing intermittent and constant in different locations is accompanied by reddening and tearing of the eye, and was initiated by triggers as in typical TN. A MS lesion of the hypothalamus is thought to be the causative agent, and this patient was pain free after being treated with Lamictal.
- In the June 1999 issue of Archives of Neurology, Dr. Mathias Hartmann, et al discuss a case of TN pain in an MS patient that was triggered by noise, such as a ringing telephone. One of their possible explanations for this phenomenon was that lesions on the pons allowed damaged auditory (hearing) and trigeminal nerve endings to cross over their impulses.