Publications

Background: Sensory threshold somatosensory electrical stimulation (St-SES) enhances sensory functions and promotes cortical plasticity in people with stroke by increasing motor cortex excitability.

Objective: To investigate the effects of St-SES during modified constraint-induced movement therapy (M-CIMT) on upper extremity muscle mechanical properties and sensory and motor functions in participants with stroke.

Design: This study is a single-blinded randomized controlled clinical trial.

Participants: Sixty participants with stroke were invited to the study. A total of 48 participants met the inclusion criteria.

Interventions: Participants were randomly assigned to three groups: St-SES + M-CIMT, M-CIMT, and a control. All groups received conventional physiotherapy three times per week for 4 weeks. In addition, one of the intevention groups underwent M-CIMT three times per week, while the other group received St-SES concurrently with M-CIMT.

Outcome Measures: The participants’ upper extremity sensory functions were assessed using the Semmes–Weinstein Monofilaments test battery, motor performance was evaluated using the Wolf Motor Function Test and Motor Activity Log, muscle mechanical properties (muscle tone and stiffness) were measured with the MyotonPRO system.

Results: As a result of a 6.2% dropout rate, the final analysis included 45 participants. The St-SES + M-CIMT group showed a significant improvement in sensory functions of upper extremity compared to other groups (p < .001). However, significant differences were not observed between the St-SES + M-CIMT and M-CIMT groups in the Motor Activity Log-28 and Wolf Motor Function Test. The St-SES + M-CIMT group showed a significant decrease in muscle tone and stiffness of the distal muscles compared to other groups (p < .001), but no significant difference was observed in the proximal muscle properties compared to the M-CIMT group (p > .05).

Conclusion: This study has demonstrated that incorporating St-SES as an adjunctive therapy to neurorehabilitation techniques can be beneficial for participants with stroke.

The results of this study suggest that St-SES + M-CIMT may have additional benefits compared to M-CIMT or conventional therapy in improving upper extremity sensory function, distal muscle tone, and stiffness in participants with stroke. There are limited studies on the use of St-SES with motor training; therefore, the findings of this study are expected to contribute significantly to the existing literature. However, no differences in functional outcomes were found between the St-SES + M-CIMT and M-CIMT groups. There is no consensus on the dose–response effects of St-SES. Consequently, future research should be supported by dose–response experiments and advanced neuroimaging methods to determine the optimal amount and duration of St-SES required to achieve sustainable effects.