Treatment of Upper Limb Paresis With Repetitive Peripheral Nerve Sensory Stimulation and Motor Training: Study Protocol for a Randomized Controlled Trial

Abstract

Background: Repetitive peripheral nerve sensory stimulation (RPSS) has emerged as a potential adjuvant strategy to motor training in stroke rehabilitation. The aim of this study is to test the hypothesis that 3 h sessions of active RPSS associated with functional electrical stimulation (FES) and task-specific training (TST) distributed three times a week, over 6 weeks, is more beneficial to improve upper limb motor function than sham RPSS in addition to FES and TST, in subjects with moderate to severe hand motor impairments in the chronic phase (>6 months) after stroke. Methods: In this single-center, randomized, placebo controlled, parallel-group, double-blind study we compare the effects of 18 sessions of active and sham RPSS as add-on interventions to FES and task-specific training of the paretic upper limb, in 40 subjects in the chronic phase after ischemic or hemorrhagic stroke, with Fugl-Meyer upper limb scores ranging from 7 to 50 and able to voluntarily activate any active range of wrist extension. The primary outcome measure is the Wolf Motor Function Test (WMFT) after 6 weeks of treatment. The secondary outcomes are the WMFT at 3, 10, and 18 weeks after beginning of treatment, as well as the following outcomes measured at 3, 6, 10, and 18 weeks: Motor Activity Log; active range of motion of wrist extension and flexion; grasp and pinch strength in the paretic and non-paretic sides (the order of testing is randomized within and across subjects); Modified Ashworth Scale; Fugl-Meyer Assessment-Upper Limb in the paretic arm; Barthel Index; Stroke Impact Scale. Discussion: This project represents a major step in developing a rehabilitation strategy with potential to have impact on the treatment of stroke patients with poor Conforto et al. Nerve Stimulation in Stroke motor recovery in developing countries worldwide. The study preliminarily evaluates a straightforward, non-invasive, inexpensive intervention. If feasibility and preliminary efficacy are demonstrated, further investigations of the proposed intervention (underlying mechanisms/ effects in larger numbers of patients) should be performed. Trial Registration: NCT02658578.

Difference between the Effects of Peripheral Sensory Nerve Electrical Stimulation on the Excitability of the Primary Motor Cortex: Examination of the Combinations of Stimulus Frequency and Duration

“…It is necessary to verify whether the more effective settings for stimulation frequency and duration derived in this study could be applied to patients in the future. In several clinical trials with stroke patients, the stimulation frequency was set at 10 Hz [ 5 , 6 , 7 , 27 , 28 , 29 ]. However, the rationale for this stimulus frequency was not specified in any of these studies.…”

Repetitive Peripheral Sensory Stimulation as an Add-On Intervention for Upper Limb Rehabilitation in Stroke: A Randomized Trial

“…The secondary outcomes 10 were the WMFT at 3 weeks as well as the following at 3 and 6 weeks: grasp and pinch strength; Motor Activity Log; active range of motion (ROM) of wrist extension and flexion; modified Ashworth scale; FMA; Barthel Index (BI); Stroke Impact Scale (SIS); Beck Depression Inventory Short Form (BDI).…”

“…Furthermore, despite the results of debriefing, subjects may have suspected that they were in an active or sham group. We opted for lower limb stimulation as previously described 10 in order to mimic active treatment, without the same effect. Further studies are necessary to compare patients' perceptions about different types of controls for RPSS.…”

“…In the active group, 1.5 hours of RPSS of the median, ulnar, and radial nerves was performed. 10 In the sham group, the tibial, superficial peroneal, and sural nerves were stimulated. Average intensities of nerve stimulation (% of sensory threshold) were as follows: In the active group, 213±95% (median), 193±88% (ulnar), and 165±79% (radial).…”

“…FES for 30 minutes, TST for 45 minutes, and instructions to perform functional tasks at home were administered to both groups. 10 Additional information is reported in Supplementary Materials.…”