Trigeminal neuralgia is a rare, but an extremely painful conditions. Patients compare the quality and the severity of pain to an electric shock. The underlying cause is usually compression of the trigeminal nerve by a blood vessel inside the skull and underneath the brain. Surgery to place a teflon pad between the nerve and the blood vessel is curative, but many patients can avoid surgery by using drugs such as carbamazepine, oxcarbazepine, baclofen, and other. Botox, which is approved only for one pain condition – chronic migraines, appears to help other painful conditions, including trigeminal neuralgia (TN). A single previous double-blind placebo-controlled study by Chinese doctors confirmed our clinical observation that Botox does indeed help TN.

A new report presented at the annual meeting of the American Headache Society, also by Chinese researchers describes another positive study. This study compared a single injection of Botox with two injections separated by two weeks. It is not clear what was the logic in giving a second treatment so soon after the first one since Botox effect lasts 3 months. They followed 81 patients for 6 months and both groups had more than 80% success in the first 3 months and somewhat less of an effect in the last 3 months of the study. This was not a blinded study, but placebo response is relatively low in TN, probably because of the high pain intensity. While this study was not as scientific as the first one, it does offer some additional evidence of the efficacy of Botox for TN. Botox is certainly much safer than medications, although facial asymmetry can be an unpleasant cosmetic side effect, especially if pain involves the second branch of the TN (middle of the face).

Several of my patients with trigeminal neuralgia (TN) responded to Botox injection (although some have not). My previous post on this topic four years ago discussed a study involving 40 patients with TN, of whom 68% responded to Botox. Recently, two new cases of TN successfully treated with Botox have been reported and in the past month I’ve treated three additional patients. Two of my patients had excellent relief and one had none.

One of the case reports was presented at the recent meeting of the American Headache Society in San Diego. This was a 65-year-old woman who suffered from very severe electric shock-like pain typical of TN. She did not respond to a variety of medications, including carbamazepine (Tegretol), but did respond to Botox injections. Botox did not eliminate her pain, but the severity of it was reduced by 50% and this significantly improved the quality of her life.

The current issue of Headache contains a report of a 60-year-old man with severe TN who also did not respond to any medications. He did obtain complete relief from Botox injections and Botox has remained effective for over 2 years.

With any new treatment we usually hope to see large double-blind controlled clinical trials and eventually an FDA approval. FDA approval usually compels insurance companies pay for the treatment. Botox injections have received approval for chronic migraines, excessive sweating, twitching of muscles around the eyes (blepharospasm), and several other conditions. Unfortunately, it is not likely that Botox will receive approval for the treatment of TN because it is a relatively rare condition, which will make it difficult to conduct a large blinded trial. Fortunately, the amount of Botox needed to treat TN is much smaller than what is used for migraines, making a little more affordable. We use 100 to 200 units of Botox for chronic migraines (the FDA-approved protocol calls for 155 units injected over 31 sites) and only 20 to 50 units for TN.