Pronunciation- Try-gem-in-el New-ral-gee-ah
Rarity- rare
Difficulty in Diagnosis- There is no clear way to diagnose either with a physical exam or laboratory testing often making it a diagnosis of exclusion.
Trigeminal Neuralgia, also known as prosopalgia, Fothergill's Disease or the Suicide Disease is a neuropathic disorder characterized by episodes of intense pain stemming from the trigeminal nerve in the face and is estimated to affect between 15,000 to 20,000 people, though that number may be low due to misdiagnosis of sufferers.
While often symptoms do not start appearing until a person is in their 50's there have been reports of patients as young as 3 years old being diagnosed.
Most attacks are unilateral (meaning they only affect one side of the face) but about 10-12% are bi-lateral or affect both sides of the face at the same time.
Referred to by some as "the most painful condition in the world", attacks can be triggered by touching the affected area, talking, eating, shaving and brushing teeth. Wind, high pitched sounds, loud noises such as concerts or crowds and chewing can aggravate the condition in many patients meaning that this condition can be very limiting and affect the quality of life in many ways, especially since symptoms can occur spontaneously with no outward stimuli.
An average attack can last from a few seconds to a few minutes and has been described as stabbing electric shocks, burning, pressing, crushing, exploding or shooting pain that becomes intractable and can occur hundreds of times in a single day.
While attacks normally affect the left side of the face, it can effect both sides of the face and has even been reported to affect the middle finger!
It may slowly spread to involve more extensive portions of the trigeminal nerve. The spread may even affect all divisions of the nerve, sometimes simultaneously. Systemic development is suggested with: rapid spreading, bilateral involvement, or simultaneous participation with other major nerve trunks. Examples of systemic involvement include multiple sclerosis or expanding cranial tumor.
There is also a variant of Trigeminal Neuralgia called atypical trigeminal neuralgia (also referred to as "trigeminal neuralgia, type 2"), based on a recent classification of facial pain. In some cases of atypical trigeminal neuralgia the sufferer experiences a severe, relentless underlying pain similar to a migraine in addition to the stabbing shock-like pains. In other cases, the pain is stabbing and intense but may feel like burning or prickling, rather than a shock. Sometimes the pain is a combination of shock-like sensations, migraine-like pain, and burning or prickling pain or can also manifest as an unrelenting, tunneling, piercing pain.
The trigeminal nerve is a mixed cranial nerve responsible for sensory data such as pressure, temperature, and pain originating from the face above the jawline-- it is also responsible for the motor function of the muscles involved in chewing but not facial expressions (such as smiling and frowning).
The current theory is that it is caused by an enlarged blood vessel (possibly the superior cerebellar artery) compressing or throbbing against the microvasculature of the trigeminal nerve near its connection with the pons. Such a compression can injure the nerve's protective myelin sheath and cause erratic and hyperactive functioning of the nerve. This can lead to pain attacks at the slightest stimulation of any area served by the nerve as well as hinder the nerve's ability to shut off the pain signals after the stimulation ends. This type of injury may rarely be caused by an aneurysm (an outpouching of a blood vessel); by a tumor; by an arachnoid cyst in the cerebellopontine angle; or by a traumatic event such as a car accident, though the cause is not often able to be found and it is then classified as "Idiopathic".
While there are ways to manage the pain, they are not often successful and include-
- Medications- carbamazepine is the first line treatment; second line medications include baclofen, lamotrigine, oxcarbazepine, phenytoin, gabapentin, and sodium valproate.
- Surgery- (often only used as a last resort when all medications fail in offering relief since evidence shows that while there can be relief from pain there will also be loss of all sensation) The focus with surgery is to relieve pressure on the nerves by decompression (either removing a tumor or otherwise taking pressure off the nerve) but the effectiveness might diminish over time.
- Glycerol injections involve injecting an alcohol-like substance into the cavern that bathes the nerve near its junction. This liquid is corrosive to the nerve fibers and can mildly injure the nerve enough to hinder the errant pain signals. In a radiofrequency rhizotomy, the surgeon uses an electrode to heat the selected division or divisions of the nerve. Done well, this procedure can target the exact regions of the errant pain triggers and disable them with minimal numbness.
