Nerve Stimulation Enhances Task-Oriented Training in Chronic, Severe Motor Deficit After Stroke

Abstract

Background and Purpose-A sensory-based intervention called peripheral nerve stimulation can enhance outcomes of motor training for stroke survivors with mild-to-moderate hemiparesis. Further research is needed to establish whether this paired intervention can have benefit in cases of severe impairment (almost no active movement). Methods-Subjects with chronic, severe poststroke hemiparesis (n=36) were randomized to receive 10 daily sessions of either active or sham stimulation (2 hours) immediately preceding intensive task-oriented training (4 hours). Upper extremity movement function was assessed using Fugl-Meyer Assessment (primary outcome measure), Wolf Motor Function Test, and Action Research Arm Test at baseline, immediately post intervention and at 1-month follow-up. Results-Statistically significant difference between groups favored the active stimulation group on Fugl-Meyer at postintervention (95% confidence interval [CI], 1.1-6.9; P=0.008) and 1-month follow-up (95% CI, 0.6-8.3; P=0.025), Wolf Motor Function Test at postintervention (95% CI, −0.21 to −0.02; P=0.020), and Action Research Arm Test at postintervention (95% CI, 0.8-7.3; P=0.015) and 1-month follow-up (95% CI, P=0.025). Only the active stimulation condition was associated with (1) statistically significant within-group benefit on all outcomes at 1-month follow-up and (2) improvement exceeding minimal detectable change, as well as minimal clinically significant difference, on ≥1 outcomes at ≥1 time points after intervention. Conclusions-After stroke, active peripheral nerve stimulation paired with intensive task-oriented training can effect significant improvement in severely impaired upper extremity movement function. Further confirmatory studies that consider a larger group, as well as longer follow-up, are needed. Corroborating evidence from a systematic review of randomized and quasi-randomized trials indicated that motor recovery after stroke may be enhanced with PNS, especially when PNS is delivered as an adjunct to motor training. 13,14A well-validated form of motor training called intensive task-oriented training has been associated with significant neuroplastic change, as well as more significant functional gains than usual and customary care, in cases of mild-to-moderate hemiparesis. 15 Further research is needed to optimize intensive task-oriented training for people with severely impaired movement function after stroke. 7 In addition, randomized controlled trials showing that PNS can enhance outcomes of task-oriented training have primarily targeted only mild-to-moderate UE impairment. [16][17][18][19] In sum, although pairing PNS with motor training can enhance motor recovery after stroke, it remains unclear how severity of motor deficit may affect responsiveness to this paired intervention.14 To address these evidence gaps, the purpose of this study was to investigate whether active PNS paired with intensive task-oriented training would lead to significantly more improved movement function than sham PNS paired with intensive ta...

Combined Brain and Peripheral Nerve Stimulation in Chronic Stroke Patients With Moderate to Severe Motor Impairment

“…Also, RPSS alone led to smaller but significant improvements in accuracy compared to sham stimulation. In another study in which RPSS alone was applied to patients with moderate to severe motor impairments prior to 4-hours modified constraint-induced therapy for ten days, clinically significant improvements were reported in the Action Research Arm Test (8). Taken together with our results, these findings suggest that a single session of RPSS and tDCS may be sufficient to drive improvements in patients with mild motor deficit but not in those with moderate to severe impairments, and that several sessions of RPSS in association with intensive training may be required to enhance outcomes in these patients.…”

Effects of peripheral nerve stimulation on paralysed upper limb functional recovery in chronic stroke patients undergoing low-frequency repetitive transcranial magnetic stimulation and occupational therapy: A pilot study

“…As object manipulation not only involves hand functions, but is also related to the functional level of the proximal part of the arm (such as the shoulder, elbow, and forearm), improvement in hand function alone may not be sufficient to reflect an improvement in object manipulation. Another study that used the WMFT as an outcome for the effects of adding PNS to a programme (Carrico et al, 2016a(Carrico et al, , 2016b provided 2 h of PNS and 4 h of upper limb functional training per day, which is twice the amount in this study.…”

“…Recovery of hand movement has been clinically reported in stroke patients after 2 h of PNS (Celnik, Hummel, Harris-Love, Wolk, & Cohen, 2007;Wu, Seo, & Cohen, 2006). Moreover, using PNS for 2 h before upper limb functional training was found to improve object manipulation skills (Carrico et al, 2016a;Carrico et al, 2016b;Conforto, Cohen, dos Santos, Scaff, & Marie, 2007;Conforto et al, 2010). Effects of upper limb function recovery were also observed when PNS was performed simultaneously with upper limb functional training (Ikuno et al, 2012).…”

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

“…Since then, other studies reported benefits of single or repeated sessions of RPSS in stroke [for a systematic review, see Conforto et al, (10)]. The bulk of the work of RPSS in stroke had focused in patients with mild to moderate motor impairments until 2016, when improvements exceeding minimal clinically important differences in the Active Research Arm Test, were reported in patients with moderate to severe impairments when 2-h RPSS was followed by 4 h of intensive task-oriented motor training for ten consecutive weekdays (11).…”