Red Light Therapy for Trigeminal Neuralgia: Scientific Evidence

This 2024 systematic review examined whether laser therapy could reduce pain in trigeminal neuralgia (TN). The review searched 5 research databases for randomized trials published between December 1983 and August 2020, narrowing 269 records to the 13 that met its criteria, which used wavelengths from 632.8 to 980 nm across treatment courses lasting 9 to 30 days. The review concluded that low-level laser therapy (LLLT) reduced pain in TN, with diode lasers appearing to work best. It also noted that no standard protocol for laser treatment has been established.

Among 120 adults who had both diabetes and trigeminal neuralgia, a 2023 randomized controlled trial in Egypt compared low-level laser therapy (LLLT) and electromagnetic therapy as additions to medication. Participants were divided into 3 equal groups of 40, with 1 group receiving medication alone, a second receiving medication plus 830 nm light at 15 mW and 150 to 170 mW/cm² for 20 minutes per session 3 times a week over 60 days, and a third receiving medication plus electromagnetic therapy. All 3 groups improved after treatment. The trial found the largest gains in the group given medication plus LLLT, which showed greater reductions in pain scores and larger increases in the electrical signal strength of the jaw muscles than either of the other 2 groups.

Across studies published between 1986 and July 2011 covering 410 patients, a 2014 review examined low level laser therapy (LLLT) for trigeminal neuralgia. The review searched 5 research databases and drew together trials using 632.5, 632.8, 808, and 830 nm light at powers from 1 to 200 mW, with doses of 6 to 10 J per point in long-standing cases and 3 to 6 J per point in recent ones. Most of the reviewed studies were associated with meaningful reductions in how intense and how frequent the pain was compared with other treatments, though a few found no difference between laser and placebo. The review described LLLT as an option that could be used without side effects.

Comparing low-level laser therapy (LLLT) against repeated magnetic pulses applied through the skull, a 2013 randomized controlled trial examined trigeminal neuralgia in people with multiple sclerosis. 30 adults aged 40 to 60 were recruited at a hospital in Saudi Arabia and divided into 2 equal groups of 15, with 1 group receiving 830 nm light at 15 mW, 150 to 170 mW/cm² and 10 Hz, applied in contact along the affected nerve branch inside the mouth for 1 to 2 minutes and then to the tenderest spots on the face for 10 minutes, and the other receiving electromagnetic stimulation at 10 Hz and 50 mA for 20 minutes, 3 times a week across 8 weeks for 24 sessions in total. Both groups improved, but the trial found that the electromagnetic group gained more, with pain scores on a standard 0 to 10 scale falling from 7.6 to 5.3 against 7.5 to 6.2 in the laser group. Maximum mouth opening also rose further in the electromagnetic group, from 15.4 to 28 mm against 16.7 to 23.9 mm with laser.

80% of patients showed excellent or good results in a 1982 observational study of helium-neon soft laser treatment for facial pain of vascular origin. The report described a helium-neon laser at 632.8 nm and 5 mW applied to points along the nerve branch serving the upper jaw and cheek, along with points on the nose and the ear. Those patients had earlier received drug treatment that produced little or no benefit, so the laser treatment appeared to help a group that had not responded to medication.

In 2021, a systematic review examined whether photobiomodulation (PBM) could serve as an alternative to standard treatments for trigeminal neuralgia. The review followed a standard reporting protocol across 3 research databases, narrowing 20 identified articles to the 6 that met its criteria, covering 193 patients treated at wavelengths from 632 to 980 nm with doses between 0.2 and 12.73 J/cm². According to the review, pain control did not differ meaningfully between PBM and conventional therapies, which positioned PBM as a treatment that could sit alongside them rather than replace them. The review rated the overall risk of bias as low, with some concerns about how participants were assigned to groups and how well the treatment was concealed.