Effects of MLS-Laser on neuropathic pain in diabetic sensomotor neuropathy

L. Yosifova, E. Vladeva, M. Siderova
Journal of IMAB, Jul-Sep;29(3):5079-5084, 2023

About 20-50 % of patients with diabetes and about 60 % of those with diabetic neuropathy develop neuropathic pain, which is characterized by tingling, burning, sharp, shooting, or stabbing sensations, and even electric shock-like sensations. Painful diabetic neuropathy can significantly affect the quality of life of patients with diabetes, the ability to perform daily activities and negatively affect mood. According to the 2021 consensus of an international panel of experts regarding the treatment of painful distal symmetric polyneuropathy, non-pharmacological forms of treatment should also be considered due to unsatisfactory pharmacotherapy. A number of studies have demonstrated the role of photobiomodulation as a non-pharmacological method of treating painful diabetic neuropathy.
The purpose of this placebo-controlled, longitudinal study was to investigate the effect of high-energy MLS-laser therapy on neuropathic pain.
Material and methods: A total of 69 cases of patients with type 2 diabetes and painful diabetic neuropathy of the lower extremities were followed, divided into two groups: an experimental - 41 patients received high-energy laser radiation and a control (placebo) group - 28 patients, with a "mock" laser treatment. For objectification of pain, the Bulgarian version of the short form of the McGill pain questionnaire, version SF-MPQ-2, which includes the visual analog scale (VAS), was used. Comparisons between groups were performed with parametric or non parametric tests depending on the distribution of the variables, the number of the compared groups and the study pre test – post test  design.
Results: The pain index, reported by the McGill questionnaire, in the experimental group, decreased by - 63.2 % at the end of the nine-day treatment and by - 56.1 % at the 90th day after the start of treatment compared to the value before therapy. In the control group, there was a minimal change at the end of treatment (day 21), which did not persist until the end of the observation period (day 90).
Conclusions: MLS laser therapy significantly increases the pain threshold and should be considered a safe, non-pharmacological adjunct to standard therapy in patients with painful diabetic peripheral neuropathy.