Influence of photobiomodulation on sensory symptoms, balance, and gait speed in chemotherapy-induced peripheral neuropathy.

Introduction: Photobiomodulation (PBM) is a non-invasive therapy that uses low-level light in the visible and near-infrared spectrum to stimulate cellular processes, promoting tissue repair and reducing inflammation without causing thermal damage. PBM has shown potential in alleviating neuropathic pain and improving nerve function by enhancing mitochondrial activity, reducing oxidative stress, and modulating inflammatory pathways. Emerging evidence suggests that PBM may be a promising adjunctive treatment for managing chemotherapy-induced peripheral neuropathy (CIPN) and improving patients' quality of life.

Objective: To evaluate the influence of photobiomodulation (PBM) on sensory complaints, balance, and gait speed in patients with chemotherapy-induced peripheral neuropathy (CIPN).

Methods: Prospective clinical study in 47 patients with CIPN in the lower limbs (CAAE: 70504423.9.0000.5382). Patients received PBM (630/850 nm), in the nerve pathway, 2 × /week for 2 weeks. The Neuropathic Pain Questionnaire (DN-4), the Chemotherapy-Induced Peripheral Neuropathy Assessment Tool (FANPIQ) and its interference items, and the Lower Extremity Functional Scale (LEFS) were used. Balance was assessed by measuring the amplitude, speed, and area of displacement with a force platform on rigid and deformable surfaces. Gait speed (GS) was assessed by the 10-m walk test. Measurements were collected at the beginning and end of treatment and analyzed with descriptive statistics and independent t-test.

Results: Sensory symptoms improved, as evidenced by the results of the DN-4 (p < 0.0001) and the FANPIQ (p = 0.0031), but not in the LEFS (p = 0.2379). There was also a significant improvement in the amplitude of the anteroposterior displacement (APD) and in the amplitude of the mediolateral displacement (MLD) (p = 0.0001 and p < 0.0001), in the velocity of the APD and MLD (p = 0.0431 and p = 0.0016), and in the displacement area (p = 0.0001). On the deformable surface, significant reductions were also observed in the APD and MLD (p = 0.0314 and p = 0.0008), as well as in the velocity of the MLD (p = 0.0091) and displacement area (p = 0.0029). GS showed improvement (p = 0.0315).

Conclusion: PBM proved to be a promising low-cost resource for the management of sensory symptoms of CIPN, with positive clinical repercussions on balance and gait speed.