What is Trigeminal Neuralgia?
Trigeminal neuralgia (tic douloureux) is a nerve disorder (neuropathy) that affects the trigeminal nerve – this nerve is responsible for providing sensation to the face. Patients with trigeminal neuralgia typically develop acute, severe, one-sided shooting pain originating near the ear and spreading outward towards the front of the face. Individuals often describe the pain as an electric-shock type sensation. The pain is in the sensory distribution of the trigeminal nerve. It is often precipitated by gentle touch, brushing teeth, or combing hair. Women are affected by the condition more commonly than men.
The pain can be excruciating – in fact, trigeminal neuralgia is associated with an increased risk of suicide due to the debilitating nature of the pain. Due to the importance of this condition, it is critical that patients understand its causes, symptoms, and treatment.
What Causes Trigeminal Neuralgia?
The trigeminal nerve exits the brainstem from a structure called the pons. Nerve branches then supply the face to provide sensation. There are three main branches of the trigeminal nerve:
- Ophthalmic branch – provides sensation to the forehead and around the eyes
- Maxillary branch – provides sensation to the nose, midface, and upper lip
- Mandibular branch – provide sensation to the lower lip and jaw
Trigeminal neuralgia is typically caused by compression of the trigeminal nerve root near its entry into the brainstem. This is most often caused by an artery or vein. Other possible causes include compression by a brain tumor (e.g., acoustic neuroma, meningioma), aneurysm, or arteriovenous malformation. Nerve compression results in nerve injury and inflammation, which causes shooting pain.
Demyelination of the trigeminal nerve may also lead to trigeminal neuralgia – this often occurs in the setting of multiple sclerosis. Occasionally acute trigeminal nerve pain is caused by herpes zoster or herpetic neuralgia. Pain is usually unilateral (one-sided), although multiple sclerosis is often associated by bilateral trigeminal neuralgia.
Studies show that high blood pressure (hypertension) and migraine headache may also be risk factors for the disease.
How Common is Trigeminal Neuralgia?
Trigeminal neuralgia is rare condition. The incidence of the disease is approximately 4-13 per 100,000 people per year. The incidence increases with age, with most idiopathic cases occurring after age 50. The disease is more frequently seen in women compared to men. Atypical or severe cases of the condition may require referral to a neurology specialist, particularly if first-line and conservative measures are unsuccessful.
Signs and Symptoms
Symptoms of trigeminal neuralgia often include severe and sudden one-sided stabbing or lancinating. Pain is often characterized as intense, electric, or shock-like, or stabbing sensations. They typically last for seconds. These episodes tend to be recurrent and involve the distribution of one or more branches of the trigeminal nerve.
The most common branches that are involved include the maxillary and mandibular divisions. Sometimes individuals experience tearing (lacrimation), eye redness (conjunctival injection), and runny nose (rhinorrhea) during episodes of pain. These are called autonomic symptoms. Severe pain can also be associated with facial muscle spasms. Pain may be provoked by gentle touch, brushing teeth, or cold air.
The diagnosis of trigeminal neuralgia is made clinically and is suggested based on symptoms and physical examination. Neuroimaging studies are typically performed to rule out secondary causes such as brain tumor, aneurysm, or multiple sclerosis. The most commonly ordered tests include CT scan or MRI of the brain MRI. The study is typically performed with and without intravenous contrast. MRI is generally preferred over CT scan as it can better visualize the brainstem and provides a more detailed image.
Trigeminal Neuralgia Treatment
The first-line treatment of trigeminal neuralgia is pharmacotherapy with Tegretol (Carbamazepine), which typically leads to significant improvement in pain levels. In addition, patients with a secondary cause of trigeminal neuralgia require treatment of the underlying condition if possible. Patients that do not respond to carbamazepine often benefit from Trileptal (Oxcarbazepine).
Lioresal (Baclofen) may be considered in those who are refractory to the aforementioned. Occasionally, Lamictal (Lamotrigine) is added on to these medications to augment pain reduction. Patients that are unresponsive to medications may consider surgical options such as microvascular decompression or gamma knife radiosurgery. Microvascular decompression is a major surgery that involves cutting open the skull and separating the blood vessels away from the trigeminal nerve. Gamma knife radiosurgery uses focused gamma radiation.
- Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition (beta version). Cephalalgia 2013; 33:629. - https://www.ichd-3.org/wp-content/uploads/2016/08/International-Headache-Classification-III-ICHD-III-2013-Beta-1.pdf
- Maarbjerg S, Gozalov A, Olesen J, Bendtsen L. Trigeminal neuralgia--a prospective systematic study of clinical characteristics in 158 patients. Headache 2014; 54:1574. - https://headachejournal.onlinelibrary.wiley.com/doi/full/10.1111/head.12441
- Bennetto L, Patel NK, Fuller G. Trigeminal neuralgia and its management. BMJ 2007; 334:201. - https://www.bmj.com/content/334/7586/201
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.