3/29/2021 8:20:00 AM Trigeminal neuralgia is painful but rare
Dear Doctor: I was diagnosed with trigeminal neuralgia a few months ago, which I had never heard of before. I have learned that successful treatment can vary from patient to patient. Can you address this disease in your column?
Dear Reader: Trigeminal neuralgia is a rare and extremely painful condition that occurs when the proper functioning of the trigeminal nerve becomes disrupted. This is the fifth cranial nerve, which is actually a pair of nerves that originate in the brain and run to the left and right sides of the face. Each side of the nerve is made up of three distinct branches. They provide sensation to the upper, middle and lower portions of the face, and also to the oral cavity.
When someone has trigeminal neuralgia, or TN, they experience sudden and severe bolts of intense pain that last anywhere from a few seconds to a few minutes. They occur between the jaw and the forehead, usually on just one side of the face, and often arrive in clusters. People describe TN's piercing pain as akin to an electric shock. The sensations can be triggered by the slightest touch or vibration, so actions like putting on makeup, shaving, brushing one's teeth or even being exposed to a breath of wind can lead to excruciating pain. The intensity of the pain, as well as its unpredictability, can become debilitating. It isn't known why, but trigeminal neuralgia rarely occurs during sleep.
Although TN can occur at any age, it has been linked to the aging process and is most often seen in people over the age of 50. It's also more common in women than in men. The main cause is believed to be contact between the trigeminal nerve and one of the blood vessels located where the nerve exits the brainstem. There is some evidence that TN runs in families. Researchers suspect this may be due to inherited blood vessel configurations. The condition is also associated with disorders such as multiple sclerosis, in which the protective myelin sheath that covers many of the nerves in the body suffers damage.
Treatment for TN begins with medications. Anticonvulsants and antispasmodics have been found to be somewhat successful at suppressing the trigeminal nerve's sporadic firing. Up to 90% of patients report at least partial pain relief. Unfortunately, the effectiveness of these drugs often plateaus and then fades. Some patients find they are unable to tolerate the drugs' challenging side effects, which can include dizziness, nausea, fatigue, drowsiness and tremor.
When drug therapies prove ineffective, surgery can become an option. This ranges from the use of radiation or chemicals to damage the nerve and "jumble" the pain pathways, to major surgery to separate the trigeminal nerve from the blood vessel that is compressing it.
Most recently, several small studies have found localized injections of Botox to be quite effective at suppressing nerve activity. This resulted in markedly fewer episodes and less pain. Study participants reported that the benefits lasted for three or more months. Although this is a promising avenue of inquiry, Botox is not yet an approved treatment for TN.