Immediate Neurophysiological effect of electrical stimulation via dry needling on H-reflex in post stroke spasticity

Background Many non-pharmacological interventions have been proposed for spasticity modulation in spastic stroke subjects.Objective To investigate the immediate effect of dry needling (DN), electrical stimulation (ES), and dry needling with intramuscular electrical stimulation (DN+IMES) on H-reflex in post-stroke spasticity.Methods Spastic subjects with stroke (N = 90) (55–85 years) were evaluated after 1 month of stroke onset using Modified Ashworth Scale (MAS) score ≥1. Subjects were randomly allocated to receive one session of DN – Soleus (N = 30), ES – posterior lateral side of the leg with 100 Hz and 250 μs pulse width (N = 30), or DN+IMES – Soleus (N = 30). MAS, H-reflex, maximum latency, H-amplitude, M-amplitude and H/M ratio, were recorded before and after one session of intervention. Relationships for each variable within group or the difference among groups were calculated by effect size.Results Significant decrease in H/M ratio in Gastrocnemius and Soleus at post-treatment within DN group (P = .024 and P = .029, respectively), large effect size (d = 0.07 and 0.62, respectively); and DN+IMES group (P = .042 and P = .001, respectively), large effect size (d = 0.69 and 0.71, respectively). No significant differences in all variables at pre-treatment and post-treatment was recorded among ES, DN, and DN+IMES groups. Significant decrease in MAS was recorded at post-treatment compared to pre-treatment within ES group (P = .002), DN group (P = .0001), and DN+IMES group (P = .0001), but not significant (P > .05) among three groups at pre-treatment (P = .194) and post-treatment (P = .485).Conclusions Single session of DN, ES, and the DN+IMES can significantly modulate post-stroke spasticity by possible bottom-up regulation mechanisms.