Cycling regimen induces spinal circuitry plasticity and improves leg muscle coordination in individuals with spinocerebellar ataxia.

ABSTRACT

OBJECTIVES: To compare the reciprocal control of agonist and antagonist muscles in individuals with and without spinocerebellar ataxia (SCA) and to evaluate the effect of a 4-week leg cycling regimen on functional coordination and reciprocal control of agonist and antagonist muscles in patients with SCA. DESIGN: Randomized controlled trial with repeated measures. SETTING: Research laboratory in a general hospital. PARTICIPANTS: Individuals with SCA (n=20) and without SCA (n=20). INTERVENTIONS: A single 15-minute session of leg cycling and a 4-week cycling regimen. MAIN OUTCOME MEASURES: Individuals with SCA (n=20) and without SCA (n=20) underwent disynaptic reciprocal inhibition and D1 inhibition tests of the soleus muscles before and after a single 15-minute cycling session. Individuals with SCA were randomly assigned to either participate in 4 weeks of cycling training (n=10) or to receive no training (n=10). The disynaptic reciprocal inhibition and D1 inhibition and International Cooperative Ataxia Rating Scale (ICARS) scores were evaluated in both groups after 4 weeks. RESULTS: Individuals with SCA showed abnormally strong resting values of disynaptic reciprocal inhibition and D1 inhibition (P<.001) and impaired inhibition modulation capacity after a single 15-minute session of cycling (P<.001). The inhibition modulation capacity was restored (P<.001), and the ICARS scores improved significantly (pre 13.5±9.81, post 11.3±8.74; P=.046) after 4 weeks of cycling training. CONCLUSIONS: A 4-week cycling regimen can normalize the modulation of reciprocal inhibition and functional performance in individuals with SCA. These findings are applicable to the coordination training of patients.