Red Light Therapy for Spinal Cord Injury: Scientific Evidence

This 2022 clinical trial tested whether near-infrared light delivered directly onto the spinal cord is safe in people with recent spinal cord injury. 12 patients already undergoing surgery to relieve pressure on the cord had a medical scattering fiber placed above the exposed cord, delivering 810 nm light at 300 mW continuously for 30 minutes a day over 7 days. The trial found no clinically meaningful changes in temperature, blood pressure, breathing rate, heart rate, or oxygen levels during treatment, and markers linked to allergic reactions and to blood clotting stayed within normal limits throughout. Markers of infection rose by day 3 and returned to normal by day 7, and 7 patients had adverse events during the study that the researchers did not consider related to the light treatment. Sensation and muscle strength scores did not change during treatment, though all 12 patients showed minor improvement by the 3-month follow-up.

Among 25 people with incomplete spinal cord injury (SCI) who completed treatment, a 2020 randomized controlled trial in Brazil tested photobiomodulation (PBM) added to physiotherapy. Both groups received physiotherapy 3 times a week, with the active group given 808 nm light at 120 mW, 4720 mW/cm², 983 J/cm², and 25 J in contact with the spine for about 17 minutes per session across 12 sessions over 28 days, and the other group given an inactive device. The active group improved more than the placebo group in sensitivity to a light touch and to a sharp point, and in muscle strength, 30 days after treatment, while the placebo group showed no significant change. The trial concluded that combining physiotherapy with PBM led to better sensory and motor recovery and a better sense of health and quality of life.

Comparing laser light delivered into the bloodstream against an identical inactive procedure, a 2012 randomized controlled trial of 36 people examined long-standing spinal cord injury (SCI) in Taiwan. 24 people with SCI were assigned to the active or inactive group, and 12 people without SCI were recruited for comparison, with the active group receiving 632.8 nm light at 4 mW for 60 minutes a day across 15 sessions over 21 days. The trial found that markers of energy production and the blood's ability to counter cell damage rose in the active group, while a marker of oxidation damage fell, and none of these shifted in the inactive group. Before treatment, the people with SCI showed more oxidation damage and poorer cell energy production than the people without SCI.