Non-invasive electrical stimulation in patients with neurodegenerative ataxia and spasticity: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND PURPOSE

There are limited treatment options for patients with neurodegenerative ataxia and spasticity. Non-invasive electrostimulation (NES) is receiving increasing interest because of its ease of implementation, cost-effectiveness and safety. A meta-analysis was conducted to evaluate the efficacy of NES.

METHODS

MEDLINE and Embase were screened for studies using NES in ataxias and spasticity. Key outcome measurements of effectiveness included changes in (1) Modified Ashworth Scale (MAS) scores, (2) cerebellar brain inhibition (CBI), (3) the nine-hole peg test (9HPT), (4) the 8-m walking time (8MWT), (5) International Cooperative Ataxia Rating Scale (ICARS) score and (6) the Scale for Assessment and Rating of Ataxia (SARA) scores.

RESULTS

Seven randomized controlled trials involving 203 patients were included. There were significant improvements in MAS (mean difference [MD] -0.42, 95% confidence interval [CI] -0.76 to -0.08, p = 0.015), CBI (MD -0.35%, 95% CI -0.42 to -0.28, p < 0.001), 8MWT (MD -1.88 s, 95% CI -3.26 to -0.49, p = 0.008), ICARS (MD -7.84, 95% CI -11.90 to -3.78, p < 0.001) and SARA (MD -3.01, 95% CI -4.74 to -1.28, p < 0.001). There was almost no heterogeneity across all outcomes except for CBI (I  = 79%). No significant changes in the 9HPT were observed comparing NES to a sham procedure (MD -3.52 s, 95% CI -9.15 to 2.10, p = 0.220). Most included studies were at low risk of bias, and no severe adverse effects were reported.

CONCLUSION

It was demonstrated that NES is an effective treatment for improving coordination and balance and increased exercise capacity in patients with ataxia and spasticity. There was also a significant modulation of CBI in ataxic patients.