- A new study from Austria supports the idea that light therapy can help people with multiple sclerosis (MS) reduce the excessive fatigue that often accompanies the disease.
- Although the study authors tried to confirm the effect of bright light therapy, they found that even low red light led to a similarly clinically significant improvement.
- More research is needed to investigate the use of light therapy, a treatment with minimal side effects, for MS fatigue.
A new study from the Medical University of Vienna in Austria has investigated the benefits of light therapy to treat the debilitating fatigue that often occurs in multiple sclerosis (MS).
Since a study from 2014 found that higher sun exposure is associated with an improvement in MS exhaustion, there has been interest in light therapy as a non-drug treatment for the disease.
The new study reports the results of a double-blind, randomized sham control trial in which participants, who were exclusively MS patients, were treated with bright white light therapy. A control group was treated with low red light.
The study found that bright white light therapy led to a clinically significant improvement in MS fatigue after just 14 days of treatment.
The new study was published in Multiple Sclerosis Journal — Experimental, Translational and Clinical.
The Effects of MS Fatigue
According to the National Multiple Sclerosis Society, 80% of MS patients are affected by severe fatigue. It usually occurs on a daily basis and is often cited as the factor that causes people with MS to abstain from work.
MS fatigue is a deeper feeling of tiredness than normal exhaustion.
Other people may regard the symptoms as signs of depression or a lack of commitment on the part of MS patients, but it is a recognized symptom of the disease.
Tiredness can worsen over the course of a day and is also aggravated by humidity and heat.
The mechanistic cause of MS exhaustion is currently unknown, although it is clear that it is not the direct result of depression or is related to the extent of MS-related physical problems.
Promising effects compared to limitations
The researchers started with 26 participants before calculating people with potential confusing causes of fatigue. They came to a final study cohort of 10 people who were treated with bright white light and 12 people who received the dim red light — sham treatment — as a control group.
The authors cite this small study population as a limitation of their study.
Recruiting for the complex study was difficult. The researchers began recruiting less than 3 months before the introduction of COVID-19 lockdowns in Austria. The participants had to visit the researchers’ outpatient clinic, undergo rigorous sleep analyses and answer questions up to four times a day for 6 weeks.
The authors suggest that general fatigue, poor mental health and sleep disorders associated with the pandemic may also have limited the effectiveness of bright light therapy.
Both groups were given a treatment lamp to use in their homes. The participants in the bright light group received a bright white lamp with 10,000 lux for the study.
The control group was given a much darker lamp that produced a red light with an intensity of less than 300 lux. Both groups were expected to use their lamps for half an hour a day.
In the bright light group, the researchers observed several indicators of improvement, including improved physical and mental performance and reduced daytime sleepiness.
“The results of our study represent a promising non-pharmacological therapeutic approach,” says study author Dr. Stefan Seidel from the Department of Neurology at the Medical University of Vienna and Vienna University Hospital.
Fatigue scores: Another story
The primary outcome the researchers aimed for was an improvement in MS exhaustion in each individual, as measured using the Fatigue Severity Scale (FSS).
At the end of the study, there was little difference between the FSS levels in the bright and sham groups, although both led to an improvement that was considered clinically significant.
The authors write: “Although we were unable to demonstrate an effect of [bright white light] that exceeds that of a placebo effect, our results are consistent with the positive effect of [bright white light] on reported MS fatigue.”
“In essence,” Dr. Jonathan Cedernäs, an expert on circadian rhythms at Uppsala University in Sweden, told Medical News Today, “we may need larger and more long-term studies — the present study only covered a two-week intervention period.”
Dr. Cedernäs was not involved in the current study.
According to him, the improvements caused by both types of light could be due to a placebo effect. “That could [simply] be because I was part of the study,” he guessed.
Another problem with the study is that the researchers did not record the time participants spent outside in natural light during the study period. The amount of light varies depending on the time of year.
Dr. Cedernäs explained to us that the
Light therapy is promising
“Many neurodegenerative diseases disrupt circadian rhythms, and this is a great area of research that requires further studies to understand cause and effect. There is […] interest in whether circadian disorders — such as those caused by chronic shift work — can increase the risk of MS. There is some support for such a connection.”
He also stated that there is “evidence that in patients with MS, a more severe disorder of the daily routine on an individual level is associated with more severe symptoms of illness, such as fatigue.”
Light is particularly attractive as a therapy because it has minimal side effects and allows doctors to safely test it as a supplement to other treatments a patient receives.
A recent meta-analysis, Dr. Cedernäs said, was encouraging and suggested that light therapy used with antidepressants is superior to the same medications with a placebo.