Trigeminal Neuralgia

Published by Dr Gigi on October 15, 2018

If you have been experiencing episodic, sharp, or stabbing pain that feels like electric shock running down the side of your face? You may have trigeminal neuralgia.

What Is Trigeminal Neuralgia?

Trigeminal neuralgia is a type or nerve pain that affects a part of the face. The pain is often episodic and sharp, it starts suddenly and  sometimes feels like electric shock. Each episode may last for a few seconds, minutes  or days and resolve completely. However, some individuals may have baseline pain that may worsen from time to time with no pain free periods.

Brief Anatomy Of Trigeminal Nerve

The Trigeminal nerve is a pair of nerves, one for each side of face. A nerve is a structure in the body that carries information in form of electrochemical impulses through the body. It is divided into 3 branches on each side that supplies the forehead, the cheeks and chin.

Who Is Affected By Trigeminal Neuralgia

Women are more commonly affected than men. Individuals over 50 are also at higher risk of TN. According to a recent study by Xu et al, individuals with diabetes mellitus  are at increased risk of developing TN, likely due to nerve damage that occur as a result of high sugar level in the blood.

Types

• Typical TN: This is the most common form of TN. The symptoms can be unpredictable, often episodic (this is the main difference between atypical and typical). Symptoms include stabbing, electric shock-like pain in a specific area of the face. Pain may be elicited by touching a  specific area of the face, chewing, talking.
• Atypical TN: It is characterized by persistent dull ache or burning sensation in one area of the face. The pain may increase progressively, becoming sharp and thereafter return to the baseline dull ache. It is often not set off by any specific activity.

Symptoms

The pain associated with trigeminal neuralgia often vary depending on the type: typical vs atypical. Pain may be triggered by minor activities such as eating, drinking, talking, wind touching the cheeks, shaving, applying makeup, brushing teeth. It may be accompanied by facial spasms.

Symptoms of Typical TN Include:
Severe, sudden onset, electric shock-like pain and sometimes burning sensations that comes and goes. The pain can be progressive and constant, as in atypical TN. The pain free periods may become shorter and painful episodes lasts longer with no painless period. TN is not fatal but may affect your quality of life, it may make you avoid social activities, deter you from engaging in some physical activities, and some people have experienced depression as a result of the discomfort.

Causes

Several experts have proposed a number of causes. In any case, it results from damage to the nerve that may be as a result of any of the following mechanisms:

• An abnormally positioned or swollen blood vessel compressing the nerve as it leaves the brain, consequently destroying the outer sheath covering the nerve.
• May be seen in individuals with multiple sclerosis (a disease that destroys the outer sheaths of nerves in the body).
• Very rarely, a tumor adjacent to the nerve will compress and damage the nerve, resulting in TN.
• Any damage to the T nerve, e.g trauma, scomplicetra of mouth surgery or sinus surgery.

Diagnosis

There is no specific test to diagnose TN.

History:  In order to diagnose you, your doctor will ask you specific questions about the type, location and triggers for your facial pain.

Neurological examinations: Your doctor may perform physical examination to determine the part of your face where the pain is occurring and which branches of the trigeminal nerve may be affected. 

Magnetic Resonance Imaging:Your doctor may obtain an MRI scan of your head to determine the cause of the trigeminal neuralgia and also rule out other causes of facial pain. MRI is useful to exclude the presence of a tumor or presence of multiple sclerosis as the cause of TN.

Facial pain may be caused by other conditions such as temporomandibular joint disorder, postherpetic neuralgia ( nerve pain often associated with shingles) cluster headaches. In order to make the diagnosis, your doctor will exclude other causes of facial pain.

Treatment
There is no known cure for TN, however symptoms may resolve after 6-12 months of recurrent TN episodes. Your doctor may prescribe some medicines to relieve your symptoms. If your symptoms are from other conditions such as multiple sclerosis, your doctor will have to treat the underlying condition.

The treatment options available include:

• Anticonvulsants: your doctor may prescribe anticonvulsants such as Carbamazepine (Tegretol), Oxcarbazepine, lamotrigine (Lamictal), phenytoin (Dilantin), gabapentin (Neurontin) clonazepam (Klonopin). Sometimes, your medicine may stop being effective at controlling your symptoms. In this case your doctor may either increase the dosage or change your medicine. Some of the side effects of anticonvulsants include nausea, drowsiness, dizziness and confusion. If you are taking carbamazepine, you will need to check your blood level and liver function.
• Muscle relaxants: They may be used in combination with carbamazepine. Examples include; baclofen (Gablofen, Lioresal). Side effects often include nausea, drowsiness and confusion.
• Botox (botulinum toxin) injections: According to a study by Allam et al, people with TN whose pain are not effectively controlled by other medications may benefit from botox injections. The only limitation is that there is need for more research in order to establish its effectiveness in treating TN.
• Surgery: Your doctor may recommend surgery if your medications are no longer able to control your pain and symptoms. Such procedures include: glycerol injections, stereotactic radiosurgery, radiofrequency thermal lesioning, gamma knife radiosurgery, microvascular decompression. Common side effect of the surgical procedures include temporary to permanent numbness in the face and the likelihood of pain returning after a while.

References

• Sandrini G, De Icco R, Tassorelli C, Smania N, Tamburin S. Botulinum neurotoxin type A for the treatment of pain: not just in migraine and trigeminal neuralgia. The Journal of Headache and Pain. 2017;18(1):38. doi:10.1186/s10194-017-0744-z.
• Bašić Kes V, Zadro Matovina L. Accommodation to Diagnosis of Trigeminal Neuralgia. Acta Clin Croat. 2017 Mar;56(1):157-161. doi: 10.20471/acc.2017.56.01.21.
• Iwai, Yoshiyasu et al. Gamma Knife Radiosurgery for Trigeminal Neuralgia Associated with Osteogenesis Imperfecta.  World Neurosurgery. Volume 115 , 24 – 28
• Kai, Ma et al. Clinical Features and Surgical Management of Cerebellopontine Angle Cholesteatoma That Presented as Trigeminal Neuralgia. World Neurosurgery. Volume 115, e7 – e12
• Wu, Min et al. Microvascular Decompression for Classical Trigeminal Neuralgia Caused by Venous Compression: Novel Anatomic Classifications and Surgical Strategy. World Neurosurgery. Volume 113 , e707 – e713
• Xu et al. Diabetes mellitus in classical trigeminal neuralgia: A predisposing factor for its development. Clinical Neurology and Neurosurgery. Volume 151, December 2016, Pages 70-72
• Lin et al. Cephalalgia. Increased risk of trigeminal neuralgia in patients with migraine: A nationwide population-based study. 2016 Nov;36(13):1218-1227. doi: 10.1177/0333102415623069. Epub 2016 Jul 19.
• Kim et al. Gamma Knife surgery for tumor-related trigeminal neuralgia: targeting both the tumor and the trigeminal root exit zone in a single session. J Neurosurg. 2016 Oct;125(4):838-844. Epub 2016 Jan 22.
• Weber K. Neuromodulation and Devices in Trigeminal Neuralgia. Headache. 2017 Nov;57(10):1648-1653. doi: 10.1111/head.13166. Epub 2017 Sep 14.
• Cruccu G. Trigeminal Neuralgia. Continuum (Minneap Minn). 2017 Apr;23(2, Selected Topics in Outpatient Neurology):396-420. doi: 10.1212/CON.0000000000000451.