Randomized Trial of Peripheral Nerve Stimulation to Enhance Modified Constraint-Induced Therapy After Stroke

Abstract

Background: Constraint-based therapy and peripheral nerve stimulation can significantly enhance movement function after stroke. No studies have investigated combining these interventions for cases of chronic, mild-to-moderate hemiparesis following stroke.

Objective: This study aims to determine the effects of peripheral nerve stimulation paired with a modified form of constraint-induced therapy on upper extremity movement function after stroke. Nineteen adult stroke survivors with mild-to-moderate hemiparesis more than 12 mo after stroke received 2 hours of either active (n = 10) or sham (n = 9) peripheral nerve stimulation preceding 4 hours of modified constraint-induced therapy (10 sessions).

Results: Active peripheral nerve stimulation enhanced modified constraint-induced therapy more than sham peripheral nerve stimulation (significance at P < 0.05), both immediately after intervention (Wolf Motor Function Test: P = 0.006 (timed score); P = 0.001 (lift score); Fugl-Meyer Assessment: P = 0.022; Action Research Arm Test: P = 0.007) and at 1-mo follow-up (Wolf Motor Function Test: P = 0.025 (timed score); P = 0.007 (lift score); Fugl-Meyer Assessment: P = 0.056; Action Research Arm Test: P = 0.028).

Conclusion: Pairing peripheral nerve stimulation with modified constraint-induced therapy can lead to significantly more improvement in upper extremity movement function than modified constraint-induced therapy alone. Future research is recommended to help establish longitudinal effects of this paired intervention, particularly as it affects movement function and daily life participation.

To claim cme credits: Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES:: Upon completion of this article, the reader should be able to: (1) Understand the role that afferent input plays with regard to movement function; (2) Understand general concepts of delivering modified constraint-based therapy in stroke rehabilitation research; and (3) Understand the rationale for applying an adjuvant intervention to optimize outcomes of constraint-based therapy following stroke.

Level: Advanced

Accreditation: : The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s). Physicians should only claim credit commensurate with the extent of their participation in the activity.

Trial registration: ClinicalTrials.gov NCT02587234.

Figure 1

Diagram of Study.

Figure 2

Comparison of Groups’ Score Changes on Wolf Motor Function Test (WMFT). Results of the WMFT (primary outcome measure) show that active peripheral nerve stimulation (PNS) can enhance outcomes of a modified form of constraint-induced therapy (CIT) significantly more than sham PNS. Score decrease on the timed portion of the WMFT, as well as score increase on the lift and the grip portions, indicate improvement in affected upper extremity (UE) motor capacity. Immediately post-intervention, as well as at 1-month follow-up, there was a significant difference between groups on the timed portion (upper image) and the lift portion (lower left image). No significant difference emerged between groups on the grip portion (lower right image).

Figure 3

Comparison of Groups’ Score Changes on Upper Extremity (UE) Motor Score of the Fugl-Meyer Assessment (FMA). Increase in FMA score indicates improvement in affected UE motor function. Results at immediately post-intervention show that active peripheral nerve stimulation (PNS) can enhance outcomes of a modified form of constraint-induced therapy (CIT) significantly more than sham PNS.

Figure 4

Comparison of Groups’ Score Changes on Action Research Arm Test (ARAT). Increase in ARAT score indicates improvement in affected upper extremity (UE) motor capacity. Results at immediately post-intervention, as well as at 1-month follow-up, show that active peripheral nerve stimulation (PNS) can enhance outcomes of a modified form of constraint-induced therapy (CIT) significantly more than sham PNS.