Trigeminal Neuralgia
Published on March 4th, 2021. Information will be updated.
Trigeminal neuralgia (also known as tic douloureux or TN) is a pain that involves the lower face and jaw, but the pain can also affect the area around the nose and the upper eye. This pain is usually intense as it is like an electric-shock pain; every patient with this feels like it is the worst pain in the world. Trigeminal neuralgia affects one side of the face, activated by routine, brushing teeth, eating, or even the wind.
Anatomy and Physiology
The trigeminal nerve is part of the cranial nerves on the head responsible for providing sensitivity to the face. There are two trigeminal nerves in which go through the right and the other to the left. Each trigeminal nerve has three distinct branches called ophthalmic (V1), maxillary (V2), and mandibular nerves (V3). The ophthalmic nerve controls sensation in the eye and forehead. The maxillary nerve takes the lower eyelid, cheek, nostril, upper lip, and upper gum. Lastly, the mandibular nerves control the jaw’s sensitivity, lower gum, lower lip, and other muscles used for chewing.
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Causes
There are two types of trigeminal neuralgias which are primary and secondary. Although the cause is unknown, the pain is associated with the irritation of the nerve. Researchers claim that the nerve’s compression at the head’s base could be the cause in primary trigeminal neuralgia. The reason is that the trigeminal nerve is connected with an artery and vein where the spinal cord connects to the brain. As a result, the nerve’s pressure makes the nerve not send the messages to the neurons properly. In secondary trigeminal neuralgia, the nerve’s pressure occurs because of a tumor that can damage the neurons’ myelin sheath, making it hard for the neurons to communicate with one another.
Risk Factors
This disease is relatively rare as less than 200,000 people are diagnosed with trigeminal neuralgia per year. Tic douloureux is most common among 50-year-old women. Another risk factor is if a patient were to have multiple sclerosis, they would have a greater risk of trigeminal neuralgia.
Signs and Symptoms
The symptoms vary depending on the severity of trigeminal neuralgia. Some patients get an immediate attack, so they report it quickly, and the treatment would be very easy for them. Other patients usually go to the dentist because it hurts their jaw, thinking it has to do something with their teeth. However, after going to the dentist to get a root canal, the patient realized that the pain got worse or is the same. Therefore, the patient then figures out it is not dental-related. There are two types of pain for trigeminal neuralgia, which are TN1 and TN2. TN1 is a sharp, throbbing, or burning pain around the eyes, lips, nose, jaw, forehead, and scalp. This type of pain gets worse and eventually longer as it progresses. TN2 is slightly less painful than TN1, but the pain is more constant, burning and aching at the face’s entire side. Suppose attacks were to occur in trigeminal neuralgia. In that case, the possible causes are touching the skin lightly, washing, shaving, brushing teeth, blowing the nose, drinking hot and/or cold beverages, a light breeze is present, applying makeup, smiling, and talking. Sadly, patients can’t do even the most basic activities of daily living because of the pain.
Diagnosis
Trigeminal Neuralgia is challenging to diagnose because other painful diseases have a similar effect to TN. Conditions such as temporal tendinitis, Ernest syndrome, occipital neuralgia, migraines, giant cell arteritis, dental pain, post-herpetic neuralgia, glossopharyngeal neuralgia, sinus infection, ear infection, and temporomandibular joint syndrome can all act like trigeminal neuralgia. Therefore, it is essential to go to the doctor when experiencing sharp pain on one side of the face. Patients should go to a primary physician first to discuss their symptoms. Then, the physician will mention a couple of specialists for the patient to go to identify the disease and cause.
Although there are no diagnostic tests for this disease, other tests such as MRI and neurological examinations will eliminate other options of causing the pain on the face’s side. MRIs (magnetic resonance imaging) can detect a tumor that is affecting the trigeminal nerve by using 3-dimensional or thin-slice dimensional testing to identify compressions caused by a blood vessel. This procedure is usually done once trigeminal neuralgia has been either suspected or confirmed according to the patient’s symptoms. Physicians will check their medical and family history as well to see if there is a genetic cause.
Treatment
Several treatments could potentially cure trigeminal neuralgia. Patients usually take medications such as Carbamazepine, Gabapentin, and Ozcarbazepine to relieve the pain. Carbamazepine is the most common medication used for trigeminal neuralgia. However, some patients aren’t affected when being treated with this medication making the physician second-guess himself/herself whether or not the patient has this disease. So, Gabapentin and Ozcarbazephine are used to treat TN. Gabapentin is used to treat epilepsy and migraine but can help treat TN. Oxcarbazepine is very similar to the function of carbamazephine, and a lot of physicians would recommend this because there aren’t that many side effects. Surgery is also a treatment for trigeminal neuralgia, but it has proven ineffective because the nerves can’t be taken out from the body, or else the face will become numb.
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Resources
Trigeminal Neuralgia – Causes, Symptoms and Treatments. (2021). American Association of Neurological Surgeons. https://www.aans.org/Patients/Neurosurgical-Conditions-and-Treatments/Trigeminal-Neuralgia.