Peripheral Neuropathic Pain Improved With Spinal Cord Stimulation, Laser Therapy

Authors of a systematic review and meta-analysis published in Contemporary Clinical Trials found evidence to support the use of spinal cord stimulation or laser therapy in the setting of peripheral neuropathic pain associated with diabetic neuropathy, failed back surgery, or carpal tunnel syndrome.

Investigators from the Hong Kong Polytechnic University in China searched publication databases through December 2021 for studies evaluating physiotherapies for neuropathic pain. A total of 17 randomized controlled trials published between 2003 and 2021 were included in this analysis.

The pooled study population consisted of 1470 patients aged 45 to 70 years. The studies recruited patients experiencing peripheral neuropathic pain associated with diabetes (n=5), carpal tunnel syndrome (n=5), cancer (n=4), or chronic low back pain (n=3).  The interventions evaluated included laser therapy (n=5), spinal cord stimulation (n=5), acupuncture (n=4), and electromagnetic stimulation (n=3).

Significant effects were observed for spinal cord stimulation among patients with diabetic neuropathy (standardized mean difference [SMD], -1.63; 95% CI, -2.06 to -1.21; I², 0.00%; P <.001), for laser therapy among patients with carpal tunnel syndrome (weighted mean difference [WMD], -1.27; 95% CI, -2.29 to -0.25; I², 98.90%; P =.01), and for spinal cord stimulation among patients with failed back surgery syndrome (SMD, -0.73; 95% CI, -1.17 to -0.30; I², 74.99%; P =.001) compared with sham or usual care.

No significant effects were reported for acupuncture in the setting of cancer-related pain (SMD, -2.09; 95% CI, -4.27 to 0.09; I², 98.0%; P =.06) or for electromagnetic therapy in the setting of diabetic neuropathy (SMD, -0.77; 95% CI, -1.82 to 0.27; I², 97.00%; P =.15) compared with sham or usual care.

When comparing the effectiveness of the interventions vs control, all 5 studies had serious or very serious risk for bias, and the quality of evidence of the included studies was low or very low.

Limitations of this analysis also included the number of available studies and the significant heterogeneity among the studies.

Study authors concluded, “This review found spinal cord stimulation as an effective intervention for the treatment of [peripheral neuropathic pain] secondary to failed back surgery syndrome and diabetic neuropathy. Laser therapy was found to be beneficial for the treatment of [peripheral neuropathic pain] secondary to carpal tunnel syndrome.” The authors further commented, “Laser therapy and spinal cord stimulation are low-risk, cost-effective, and nonminimally invasive interventions that are unlikely to result in negative or adverse outcomes.”