Bright light therapy shows hope for MS fatigue in small study

A drug-free approach to multiple sclerosis (MS) fatigue showed some promise in a recent study.

Participants used a bright light therapy (BLT) machine for 30 minutes every day for two weeks. In the main group, the light worked normally, but in the control group, the machine emitted a dim red light, rather than the usual bright white that is used for therapy.

Researchers measured fatigue using the Fatigue Severity Scale (FSS). A score change in the FSS of 4.05 points is classed as clinically significant.

The people in the group given the BLT saw their scores decrease from an average of 46.07 to 39.62 after the two weeks, whereas the control group only saw a decrease from 48 to 46.08, which wasn’t clinically significant.

While there was an improvement for people using the BLT, there were only 26 participants who took part – stringent test requirements for sleep disorders slowed the study’s recruitment, and it was further disrupted by the pandemic which limited the number of people who could take part. The team noted that this meant the study didn’t have the mathematical power to declare a statistically meaningful effect.

They also believed that the pandemic may have diminished the benefits of BLT, saying that research shows the pandemic has caused worsening fatigue and poorer mental health for a lot of people.

The researchers did not assess for sunlight exposure. Given that the theory behind BLT is that exposure to light can affect mood, they suggested that future studies should try to include this data, as well as seek to enrol more patients.

“This could help determine whether bright light is effective to counteract MS-related fatigue,” they wrote.