Trigeminal Neuralgia (TN), also known as Tic Douloureux, is considered by many to be the "most terrible pain known to man." The electric shock-like pain generally is on one side of the face and is spasmodic, coming in short bursts lasting a few seconds. Several attacks can follow each other within minutes. There are often trigger points, places on the face which, if touched, trigger an attack.. Eating, shaving, applying makeup and talking can be triggers. There can be periods of remission when pain is completely absent. These periods of remission, which can last days, weeks, months, even years, are unpredictable and without medical treatment, the pain usually returns.
TN is a very rare condition. Statistics vary, but TN occurs in approximately 150 per million people per year. Medical literature notes this condition is rare for anyone under age 50 but in reality, TN is known to exist in many younger individuals including children.
Trigeminal Neuralgia was described as early as the first century A.D. in the writings of Aretaeus.. Early treatments included bloodletting and bandages containing poisons such as arsenic, mercury, hemlock, cobra and bee venom. An 18th century French surgeon, Nicolaus Andre coined the condition "Tic Douloureux," which means "painful spasm."
Several syndromes are closely related to TN, but have specific unique features as well. These include post-herpetic neuralgia, atypical facial pain (ATFP), and TN resulting from multiple sclerosis (MS). Although the distinctions tend to be fluid, these are discussed separately.
There are some relatively effective treatments for TN. Unfortunately, although some of the treatments are becoming standard, there is no single treatment that is effective for all victims.
A SHORT ANATOMY LESSON
Trigeminal Neuralgia is a disorder of the trigeminal nerve, one of twelve pairs of cranial nerves on each side of the head.
The cranial nerves control movement and sense pressure, touch, pain and temperature in the head and neck. These twelve cranial nerves are numbered from 1 to 12 using Roman numerals - e.g. I II III IV V VI VII etc..
You have two trigeminal nerves, one on the right side of your head and one on the left. The trigeminal nerve, the largest cranial nerve can be seen here.
Since the trigeminal nerve is the fifth cranial nerve, it is referred to as "V" in medical literature. The word "trigeminal" derives from the Latin word "tria" which means "three" and from "geminus" which means "twin" and refers to the fact that the trigeminal nerve has three distinct branches on each side of the head. These branches are referred to as V1, V2, and V3. The following table lists these branches and describes what areas each branch affects.
V. TRIGEMINAL NERVE - Fifth Cranial Nerve
Division Click to see a picture Areas Affected Function
V1 Opthalmic
eye, forehead and nose Sensory-1
V2 Maxillary
upper teeth, gums and lip, the cheek, lower eyelid and the side of the nose Sensory-1
V3 Mandibular
lower teeth, gums and lip Sensory-1
jaw Motor-2
1. SENSORY: Transmits pressure, touch, pain and temperature signals to the brain.
2. MOTOR: Controls movement.
For a more in depth discussion of the trigeminal nerve, see
You've Got Some Nerve (12 of Them): The Trigeminal Nerve
by Richard Schuerger, Ph.D., Neurosciences Guide at about.com
For an exceptional, detailed anatomy tour of all aspects of the Trigeminal Nerve, see
Trigeminal Nerve Anatomy
written by Jeremy S. Melker, a medical student at the University of
Florida. With complex interactive graphics, this is a site not to be missed to gain insight into the complexity of the trigeminal nerve.
CAUSES
There are a number of causes of Trigeminal Neuralgia:
• Pressure of a blood vessel on the root of the trigeminal nerve.
• Demyelinization of the nerve. In rare instances (less than 3%), TN is a symptom of Multiple Sclerosis which destroys the myelin sheaths protecting nerve fibers. Trigeminal Neuralgia is rarely the first symptom of Multiple Sclerosis and typically appears in advanced stages of MS.
• Pressure of a tumor on the trigeminal nerve (rare)
• Physical damage to the nerve caused by dental or surgical procedures, injury to the face or infections.
• Unknown. Not all cases seem to have a clear cause.
• There is some speculation that some cases of trigeminal neuralgia may be inherited. See references and more information at: OMIM™ Online Mendelian Inheritance in Man
SYMPTOMS
TN pain is usually described as a sudden sharp electrical, shocking, stinging, stabbing pain that lasts for several seconds and may repeat many times over the course of the day. Usually only one side of the face is affected with pain, but TN on both sides (bilateral TN) is known to exist. TN pain is often triggered by certain stimuli, such as touching the face, eating, talking, shaving, etc. These triggers vary from person to person. The pain may last for days, weeks, or months and then may disappear for months, even years.
Area of Pain
The area of facial pain is reflected by which of the three branches of the trigeminal nerve is affected. From the brief "anatomy lesson" above, we see that
V1 (Opthalmic) the first branch affects the eye, forehead and nose.
V2 (Maxillary) the second branch affects upper teeth, gum and lip, the cheek, lower eyelid and the side of the nose.
V3 ((Mandibular) the third branch affects lower teeth, gum, lower lip and jaw.
TN pain can involve one or more branches of the trigeminal nerve.
"Classic" TN Pain
In classic TN described in medical literature, the pain is extremely sharp, throbbing, and shock-like. There is no facial numbness or weakness. With classic TN pain, there are distinct periods of remission, when there is no pain at all. Classic TN generally responds well to Tegretol, an anti-convulsive drug used to treat seizure disorders.
Atypical TN Pain
One typical feature of TN is that it is rarely typical. For many TN patients, the condition does not conform to the symptoms of "classic" TN. In addition to the stabbing shock-like pain, many victims experience various kinds of pain that they may describe as throbbing, burning, crushing, pulsating, etc. For some, there are no remissions from the pain. These "atypical" forms of TN are often very difficult to treat.
DIAGNOSIS
A thorough medical exam and history of symptoms should be done along with medical tests to rule out any serious medical problems. These tests can include a CAT scan or MRI. In some cases, high-definition MRI angiography (MRTA) of the trigeminal nerve and the brain stem can identify where the nerve is compressed by a vein or artery but more often than not, no cause is found for the pain. If the pain is diminished with carbamazepine (Tegretol) treatment, this is a positive indicator for a diagnosis of TN. A special MRI technique, 3-D volume acquisition, performed with contrast injection, can detect 80% of the time whether a blood vessel pressing on the trigeminal nerve is causing TN pain.
However, up to now, no medical test exists that clearly diagnoses all cases of TN. TN diagnosis should not be difficult, especially in cases of classic TN where the symptoms are clear and distinct. Yet time and again, TN patients have seen numerous medical professionals and have had multiple dental procedures performed before a diagnosis is made. Sometimes years, even decades pass before the patient is diagnosed. In some instances, the diagnosis is missed because the patient does not display "classic" TN symptoms but this does not explain entirely why so many TN patients are misdiagnosed.
TREATMENT
Initial treatment for TN is usually medication with cabamazepine (Tegretol®) being the first drug of choice. Other drugs such as baclofen (Lioresal®) , clonazepam (Klonopin ®) and gabapentin (Neurontin®) are often used alone or in combination. Trileptal, a drug which was recently approved for use in the US, appears to have fewer side-effects than Tegretol and is often effective in controlling TN pain. When medication fails, surgery may be considered. For an overview and in depth description of treatments for TN
The vast majority of TN sufferers will initially find relief with specific medications such as carbamazepine (Tegretol®), oxycarbazepine (Trileptal), phenytoin (Dilantin®), and gabapentin (Neurontin®). These drugs, also used to control seizures in patients with epilepsy, reduce the trigeminal system hyperactivity that causes TN. Regular pain killers, including narcotics, generally do not reduce TN pain.
As the severity and frequency of TN attacks increase over time, a higher drug dose may be required. Unfortunately, these medications may produce unpleasant or even intolerable side effects. Over half of TN sufferers develop pain that can no longer be controlled by medications alone, and various surgical treatment options should be considered.
