Fatiguing Arm Exercise Following Stroke

Neural Mechanisms Mediating Interlimb Transfer Following Stroke

This study investigates the effects of sub-maximal exercise to task-failure (e.g., fatigue) with the less involved, or so-called non-paretic hand, in people who have experienced a stroke. In previous work the investigators found that non-paretic hand exercise to task-failure increased excitability of the motor cortex in the more involved hemisphere and produced behavioral improvements in the unexercised paretic hand. Importantly, the magnitude of increased brain excitability is greater than what has been observed following brain stimulation with either repetitive transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS) and lasts longer. This approach could be implemented in the clinical setting and could be accessible to a greater number of people than brain stimulation. The investigators' goals in the current study are to: repeat previous findings in a different group of participants and investigate the neural mechanisms that produce brain and behavioral facilitation in order to inform development of this approach for clinical implementation.

Study Overview

• Status: Completed
• Conditions: Stroke
• Intervention / Treatment: Other: submaximal exercise (grip)

Detailed Description

The long-term goal is to restore upper extremity (UE) motor function following stroke. The overall objective of this proposal is to improve the investigators' understanding of neural mechanisms contributing to inter-limb and inter-hemispheric transfer following non-paretic limb exercise to task failure. The investigators will use transcranial magnetic stimulation to probe acute adaptations in cortical excitability, intracortical and inter-hemispheric circuits that accompany behavioral facilitation of the paretic hand.

The work proposed in this two year project will enable the investigators to obtain three data elements critical to complete the working hypothesis:

1. . Changes in intracortical and interhemispheric inhibition in both hemispheres following non-paretic limb exercise to task-failure.
2. . Behavioral effects using a motor task involving manipulation and dexterity.
3. . Determine the persistence and consistency of neural and behavioral facilitation.

• Study Type: Interventional
• Enrollment (Actual): 15
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32608
      • North Florida/South Georgia Veterans Health System, Gainesville, FL

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• individuals at least 6 months post-stroke in the cortical or sub-cortical distribution with residual upper-extremity hemiparesis
• Non-Veteran Participants are eligible

Exclusion Criteria:

• multiple strokes
• strokes in both hemispheres
• brainstem/medullary/cerebellar stroke
• seizure disorder
• metal implants in head or neck
• pacemaker or other implanted device
• inability to produce any measurable grip force

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Task-failure, Extended Session; Repeated sub-maximal gripping exercise with the less affected hand to task-failure - followed by repeated measurements (5) during recovery period	Other: submaximal exercise (grip); participants perform repeated gripping with visual feedback to task failure

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Short Intracortical Inhibition (SICI)	SICI is a neurophysiologic measure of intra-cortical inhibition, obtained using transcranial magnetic stimulation (TMS) measured here in the ipsilesional hemisphere (IH) at each point to determine how it is modulated in response to task-failure. SICI is quantified as a ratio where values <1 reflect inhibition and >1 disinhibition or relative excitation. In health, SICI is ~0.5. Thus if SICI = 0.8, while <1 it would indicate less inhibition than expected in health. Transient change in SICI from 0.8 to 1.1 over the course of this experimental paradigm would reflect a period of relative excitation in response to the exercise paradigm.	baseline, post task-failure (minutes to an hour), every 45 min up to 3.5 hours post-task-failure (7 points total)
SICI Ratio	SICI is a neurophysiologic measure of intra-cortical inhibition, obtained using transcranial magnetic stimulation (TMS) measured here in the ipsilesional hemisphere (IH) at each point to determine how it is modulated in response to task-failure. SICI is quantified as a ratio where values <1 reflect inhibition and >1 disinhibition or relative excitation. In health, SICI is ~0.5. Thus if SICI = 0.8, while <1 it would indicate less inhibition than expected in health. Transient change in SICI from 0.8 to 1.1 over the course of this experimental paradigm would reflect a period of relative excitation in response to the exercise paradigm.	Baseline, pre-exercise of 8 repeated sessions

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Box and Blocks Test (BBT)	The BBT measures motor function/dexterity, scored as the number of blocks transferred in 1 minute. Here function of the paretic hand was measured at each time point: baseline, post-task failure, 45min post, 90min post, 135min post, 180min post, 225min post-task failure to determine the change in paretic hand BBT performance following exercise to task-failure. Scores are numeric ranging from 0 (no blocks transferred) to whatever the participant is able to achieve. Healthy age-matched adults without motor disability score in the range of 60 (+/- 10) blocks transferred in 1 minute.	baseline, post task-failure (requires variable timeline from minutes to an hour), every 45 min up to 3.5 hours post-task-failure (7 points total)
Box and Blocks Test (BBT)	The BBT measures motor function/dexterity, scored as the number of blocks transferred in 1 minute. Here function of the paretic hand was measured prior to exercise at each of 8 repeated sessions conducted twice weekly for 4 weeks to determine the change in paretic hand BBT performance following repeated sessions of exercise to task-failure. Scores are numeric ranging from 0 (no blocks transferred) to whatever the participant is able to achieve. Healthy age-matched adults without motor disability score in the range of 60 (+/- 10) blocks transferred in 1 minute.	baseline, pre-exercise of 8 repeated sessions

Collaborators and Investigators

• Sponsor: VA Office of Research and Development
• Investigators: Principal Investigator: Carolynn Patten, PhD, North Florida/South Georgia Veterans Health System, Gainesville, FL

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2016
• Primary Completion (Actual): May 21, 2018
• Study Completion (Actual): May 21, 2018

Study Registration Dates

• First Submitted: October 14, 2016
• First Submitted That Met QC Criteria: June 20, 2017
• First Posted (Actual): June 21, 2017

Study Record Updates

• Last Update Posted (Actual): June 4, 2020
• Last Update Submitted That Met QC Criteria: June 1, 2020
• Last Verified: June 1, 2020

More Information

Terms related to this study

• Keywords: hemiparesis
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Stroke
• Other Study ID Numbers: N1759-P

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
• product manufactured in and exported from the U.S.: No