The Cortical Motor Effects of PNS and AO on Motor Training in Chronic Stroke

The Motor Effects of Combined Peripheral Nerve Electrical Stimulation and Action Observation on the Affected Hand in People With Stroke

This study aimed to investigate if peripheral nerve stimulation (PNS) paired with action observation (AO) would augment motor training in promoting corticomotor excitability for the paretic hand in people with stroke. Twenty subjects in chronic stage of stroke were exposed to 3 different interventions involving one-hour PNS or sham PNS paired with 30 minutes of AO or sham AO, all followed by 30 minutes of finger abduction training in 3 separate sessions.

Study Overview

• Status: Completed
• Conditions: Stroke
• Intervention / Treatment: Genetic: PNS+AO+Training; Genetic: PNS+AOsham+Training; Genetic: PNSsham+AOsham+Training

Detailed Description

The investigator's previous study (Liu & Au-Yeung, 2017; PMID: 28383292) has demonstrated that 1-hour peripheral nerve stimulation (PNS) applied to the radial and ulnar nerves of the paretic UL of people with chronic stroke can increase transcranial magnetic stimulation (TMS)-evoked excitability of corticomotor pathways in both hemispheres projected to the contralateral first dorsal interosseous (FDI) hand muscle, and also improve dexterity in the paretic hand. This bi-hemispheric effect of PNS suggests that certain additional therapies such as action observation (AO) and motor training should be incorporated to strengthen the plastic corticomotor adaptation specifically for paretic UL control. The hypothesis of this study is that PNS paired with AO would augment task training of the paretic hand by increasing the corticomotor excitability in the lesioned hemisphere for the trained hand muscle in people with stroke, with associated dexterity function improvement. Twenty subjects were recruited by convenience in the community. They then attended an assessment session to evaluate the baseline sensorimotor status of their paretic upper limb. After the clinical tests，the subjects were introduced the assessment procedure for measuring corticomotor excitability with transcranial magnetic stimulation (TMS). After 1-week intermission, the subjects returned for 3 intervention sessions with different protocols including (1)PNS+AO+Training; (2)PNS+AOsham+Training; and (3)PNSsham+AOsham+Training. These 3 intervention sessions were arranged in random sequence for subjects. For "PNS+AO+Training" session, electrical stimulation was applied to the radial and ulnar nerve (PNS) of the paretic arm for 60 minutes. During the last 30 minutes of PNS, action observation (AO) was introduced in which subjects were required to watch a series of video clips. After one hour's PNS+AO, the subjects then proceeded to a 30-minute period of motor training of paretic hand. During "PNS+AOsham+Training" session, PNS was given as described before. During the last 30 minutes of the PNS, subjects were shown different photos illustrating a letter, a number or a hand as AOsham. The protocol of motor training was the same as described before. In the session of "PNSsham+AOsham+Training", The 1-hour PNSsham was conducted with the electrical stimulation unit turned on but without current output. The protocols for AOsham and motor training were the same as those described before.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 43 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• age between 40 and 80 years;
• has history of first hemispheric stroke of 6or more months;
• presence of electromyographic signals in first dorsal interosseous (FDI) during active abduction of the index finger contralateral to the lesioned hemisphere;
• medically stable;
• able to comprehend instructions.

Exclusion Criteria:

• past history of musculoskeletal or neurological impairment in the paretic upper limb;
• recurrent stroke;
• cognitive impairment (Mini-mental state examination (MMSE) < 24);
• visual impairment not correctable by optical lens;
• presence of metal in the head region or a cardiac pacemaker as contraindications for TMS (Rossi et al., 2009).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PNS+AO+Training; adopted "PNS+AO+Training" as the intervention	Genetic: PNS+AO+Training; Electrical stimulation was applied to the radial and ulnar nerve (PNS) of the paretic arm for 60 minutes. During the last 30 minutes of PNS, action observation (AO) was introduced in which subjects were required to watch a series of video clips. After one hour's PNS+AO, the subjects then proceeded to a 30-minute period of motor training of paretic hand.
Experimental: PNS+AOsham+Training; adopted "PNS+AOsham+Training" as the intervention	Genetic: PNS+AOsham+Training; PNS was given as described before. During the last 30 minutes of the PNS, subjects were shown different photos illustrating a letter, a number or a hand as AOsham. The protocol of motor training was the same as described before.
Placebo Comparator: PNSsham+AOsham+Training; adopted "PNSsham+AOsham+Training" as the intervention	Genetic: PNSsham+AOsham+Training; The 1-hour PNSsham was conducted with the electrical stimulation unit turned on but without current output. The protocols for AOsham and motor training were the same as those described before.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Corticomotor excitability evoked by Transcranial magnetic stimulation (TMS)	Corticomotor excitability in terms of the slope of the MEP recruitment curve and peak MEP amplitude captured for the contralateral FDI hand muscle in both hemispheres were assessed.	90 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hand dexterity of paretic hand evaluated with Purdue Pegboard	The score was the total number of pins inserted into the holes with paretic hand in 30 seconds.	24 hours

Collaborators and Investigators

• Sponsor: The Hong Kong Polytechnic University

Study record dates

Study Major Dates

• Study Start (Actual): June 23, 2014
• Primary Completion (Actual): June 1, 2015
• Study Completion (Actual): June 30, 2015

Study Registration Dates

• First Submitted: June 28, 2018
• First Submitted That Met QC Criteria: August 8, 2018
• First Posted (Actual): August 10, 2018

Study Record Updates

• Last Update Posted (Actual): August 10, 2018
• Last Update Submitted That Met QC Criteria: August 8, 2018
• Last Verified: August 1, 2018

More Information

Terms related to this study

• Keywords: Transcranial Magnetic Stimulation; Electrical Stimulation; Cortical Excitability
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Stroke
• Other Study ID Numbers: HSEARS20140617001-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No