Neural mobilisation effects in nerve function and nerve structure of patients with peripheral neuropathic pain: A systematic review with meta-analysis

Objective: To assess the effects of neural mobilisation on nerve function and nerve structure of patients with peripheral neuropathic pain. Methods: A systematic review with meta-analysis was conducted. Medline, Embase, CINAHL, Cochrane Library, and World Health Organization International Clinical Trials Registry Platform were searched without restrictions. Eligibility criteria included controlled trials or quasi-experimental studies comparing neural mobilisation versus sham, active or inactive control in adults with peripheral neuropathic pain. Primary outcomes were the change in peripheral nerve cross-sectional area. Secondary outcomes included nerve echogenicity, nerve excursion and nerve conduction. Random effects meta-analysis was conducted. Risk of bias was assessed with the Cochrane Collaboration tool, and certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation framework. Results: Eleven randomised controlled trials and four quasi-experimental studies (total sample = 722 participants) were included. Thirteen studies included participants with carpal tunnel syndrome. Two studies examined the cross-sectional area, revealing improvements (i.e., a reduction) in the cross-sectional area after the neural mobilisation. Neural mobilisation improved motor [mean difference = 2.95 (95%CI 1.67 to 4.22)] and sensory conduction velocity in short-term [mean difference = 11.74 (95%CI 7.06 to 16.43)], compared to control. Neural mobilisation did not alter distal motor or sensory latency. Conclusion: Neural mobilisation seems to improve (i.e., a reduced) the cross-sectional area (very low-quality evidence) and sensory conduction velocity (very low-quality evidence). Neural mobilisation was superior to control in improving motor conduction velocity in patients with peripheral neuropathic pain with moderate quality evidence. Distal motor or sensory latency presented similar results compared to other interventions. Our findings should be interpreted cautiously since most studies included patients with carpal tunnel syndrome.