Allergan, Inc., a major manufacturer of both prescription and non–prescription products, has awarded NYUCD a $100,000–plus grant to mount a six–month pilot study to assess whether BOTOX® (Botulinum Toxin Type A) injections can reduce sudden episodes of stabbing, electric shocklike facial pain associated with paroxysmal trigeminal neuralgia, one of the most painful afflictions known.

The condition, affecting approximately five in 100,000 Americans, occurs when the fifth cranial (trigeminal) nerve causes intense pain in areas where the branches of the nerve are distributed—particularly the lips, eyes, nose, scalp, forehead, upper jaw, and lower jaw.

BOTOX® is Allergan’s brand name for a toxin derived from the bacterium Clostridium botulinum, which is injected in small, diluted amounts to soften wrinkles, and to stop muscle contractions in order to alleviate blepharospasm (uncontrolled blinking) and cervical dystonia (involuntary contractions of the neck and shoulder muscles that cause the head to twist in abnormal positions). BOTOX® can also block the release of certain neurotransmitters, making it an effective treatment for migraine and tension headache pain. Similarly, it is hypothesized that BOTOX® can inhibit the neurotransmitters that cause trigeminal neuralgia pain.

The NYUCD study marks the first time that researchers are comparing BOTOX® against other medications for trigeminal neuralgia pain, said the coinvestigators, Dr. David Sirois, an Associate Professor of Oral and Maxillofacial Pathology, Radiology and Medicine at the NYU College of Dentistry; and Dr. Andrew Blitzer, a Professor of Clinical Otolaryngology at Columbia University College of Physicians and Surgeons. Although BOTOX® proved effective against trigeminal neuralgia pain in one earlier study, that trial had only 13 subjects and did not include other medications or a placebo, for comparison.

Thirty subjects are enrolled in the NYUCD study, with half receiving BOTOX® and half a placebo injection. The subjects may also take other medications, such as anti–convulsant and anti–depressant drugs commonly used for trigeminal neuralgia pain. The researchers are assessing whether BOTOX® provides enough pain relief to enable a reduction in the other medications, thereby leading to a decrease in side effects and an improved quality of life.

If BOTOX® proves effective in this pilot study, a second, larger trial will be required to gain Food and Drug Administration approval to market BOTOX® for trigeminal neuralgia pain.