Effect of high power dual wavelenght NIR laser emission in a rat model of compressive pain

Di Cesare Mannelli L., Ghelardini C., Micheli L., Cialdai F., Vignali L., Fusi F., Monici M.
Energy for Health [14] 2015

Chronic pain condition, such as neuropathic pain, is one of the most important health problems worldwide and, due to its uncertain etiology and poor response to therapy, it represents an important challenge for medicine. Although, nowadays, there are many drugs for the treatment of chronic pain, their use is limited by the frequent side effects and, in some cases, ineffectiveness.
Thus, the search for new therapeutic strategies which minimize this important problem is actually growing.
Since many years, laser therapy has been used as a physical therapy for pain relief and has become increasingly popular because it is non-invasive and no side effects have been reported after treatment. However, its true effectiveness is still controversial because of the counteracting results reported in literature.
In the present study we investigated the effectiveness of a high power, dual wavelenght NIR laser source in producing fast analgesic effect in a rat model of neuropathic pain, induced through loose ligation of the sciatic nerve. Twelve animals were included in the study and two treatment protocols were tested, one performed daily, the other every 48 hours, with a total of 5 applications.
Both protocols used were able to statistically increase the pain threshold of the ipsilateral paw (the one with loose ligation of the sciatic nerve), starting 5 min after their first applications. The anti-hyperalgesic effect of laser treatment terminated 60 min after application. It started again, showing the same anti-hypersensitivity profile, during the subsequent applications.

The treatment protocol tested in this in vivo study in animal model might be applied to give the patient immediate pain relief and combined with treatments aimed to reduce inflammation, thus leading to analgesic effects that lasts over time.