Scott Diehl, PhD, a researcher at the Rutgers School of Dental Medicine, has received a second grant of $350,000 from the Facial Pain Research Foundation to explore a possible genetic basis for trigeminal neuralgia (TN), an orofacial pain condition that affects one in 10,000 people.
Diehl is collaborating with researchers from Oregon Health and Science University and the University of Toronto. This grant allows Diehl, who specializes in genetic research, to continue work he began in 2015 with an earlier grant from the foundation.
TN affects the trigeminal nerve, which spans from below the jaw to above the eye, and leads to episodes of debilitating pain. Its onset often is sudden and random, beginning with an episode of severe pain that reoccurs.
“One day something just happens to trigger the episode. The nerve will just start firing uncontrollably, and they’ll experience one to two minutes of severe facial pain where they feel like they’ve been hit with a baseball bat,” said Diehl, who also is a professor in the Department of Oral Biology.
Sometimes, a light touch to the face or a mundane activity like tooth brushing will trigger these short periods of excruciating pain. Other times, there is no catalyst.
“People live in terror of what’s going to trigger another episode. They might go hours or days before it happens again,” said Diehl.
Until recently, TN mostly was attributed to neurovascular compression, when a blood vessel wraps around the nerve and compresses it, eventually causing damage. While this can be surgically repaired, not all TN incidents are caused by compression and surgery is not always effective, Diehl said. In other cases, anti-seizure medications can manage pain, though they can have side effects and lose efficacy over time.
Recent research suggests, however, that at least some cases of TN might be hereditary.
“We find that with 7% to 10% of patients, there’s a family history, said Diehl, who is now working with samples from more than a thousand TN patients.
Diehl is especially interested in testing samples from younger patients, who often don’t have neurovascular compression and are believed to be more likely to carry genes that cause TN to develop. Diehl hopes that discovery of genetic mutations that cause TN will allow researchers to develop new cures or more effective treatments.
“It’s possible that novel targets discovered from genetic studies of TN could lead to better ways of treating other, more common types of chronic pain caused by nerve damage for which we have no effective therapies, and as a result contribute to the opioid crisis in our country today,” said Diehl.