Researchers at the Optics and Photonics Research Center (CEPOF; São Paulo, Brazil) have developed a device that combines low-intensity laser light and therapeutic ultrasound to reduce the pain experienced by patients with fibromyalgia, a chronic disease that involves widespread nonarticular high-intensity pain lasting longer than three months.
The research team has shown that application of the combination therapy device to the palms instead of to tender points on different parts of the body has better analgesic and anti-inflammatory effects. As a result of pain reduction, patients also sleep better and are able to perform daily tasks with less discomfort. Their overall quality of life also improves.
In their paper that describes the work, the researchers detail the concomitant application of low-intensity laser light and therapeutic ultrasound for three minutes to the palms of the hands of patients diagnosed with fibromyalgia. The treatment consisted of 10 twice-weekly sessions.
"The study describes two innovations: the device and the treatment protocol. By emitting laser light and ultrasound simultaneously, we succeeded in normalizing the patient's pain threshold. Application to the palms differs from the focus on tender points found practically everywhere today in fibromyalgia care," says Antônio Eduardo de Aquino Junior, a researcher at the University of São Paulo's São Carlos Physics Institute (IFSC-USP) in Brazil and a coauthor of the article.
In the study, 48 women aged 40-65 and diagnosed with fibromyalgia were divided into six groups of eight at the Clinical Research Unit run by IFSC-USP in partnership with the Santa Casa de Misericórdia hospital in São Carlos, São Paulo State. Three groups received applications of laser or ultrasound separately or combined in the region of the trapezius muscle. The other three groups received applications only to the palms.
The results showed that treatment involving application to the palms was more effective regardless of the technique, but the laser-ultrasound combination significantly improved the patients' condition. Assessments were performed using the Fibromyalgia Impact Questionnaire (FIQ) and the Visual Analogue Scale for Pain (VASP).
A comparison of the groups showed a difference of 57.72% in functionality improvement and of 63.31% in pain reduction for the ultrasound-laser group in the case of application to the trapezius. Ultrasound-laser application to the palms produced a 73.37% difference in pain reduction compared with application to the trapezius.
"Previous studies showed that patients with fibromyalgia had larger numbers of neuroreceptors near blood vessels in the hands. Some patients even had red points in this region. We therefore changed focus to test the direct action of the technique on these sensory cells in the hands rather than just so-called pain trigger points, such as the trapezius, which is typically very painful in fibromyalgia patients," says Juliana da Silva Amaral Bruno, a physical therapist and first author of the study.
The study showed that application to the hands affects all pain points in the patient's body. The same group had previously published an article describing a case study in applying the device to pain points. Although the results of this first study were satisfactory, global pain reduction proved impossible.
"Combined application of ultrasound and laser to pain points such as the trapezius was highly effective but did not succeed in reaching the other main innervations affected by the disorder," Bruno says. "Application to the palms of the hands had a global result, restoring the patient's quality of life and eliminating her pain."
According to the study, the optimization of peripheral and brain blood flow via the activation of sensitive areas of the hands during the sessions normalized the patient's pain threshold. "It's important to bear in mind that this isn't a cure, but a form of treatment that doesn't require the use of drugs," Aquino says.
According to Aquino, the new device that combines ultrasound and laser therapy should come to market in early 2019. It is currently being tested for other pathologies by researchers at the São Paulo Research Foundation (FAPESP) Research, Innovation and Dissemination Centers (RIDCs).
"We're testing it for osteoarthritis, knees, hands, and feet, and the results have been interesting. Other projects are being designed for other diseases," Aquino says.
Full details of the work appear in the Journal of Novel Physiotherapies.