Premotor Cortex: A New Target for Stroke Motor Rehabilitation Using Transcranial Magnetic Stimulation
Overview
- Phase
- N/A
- Intervention
- Not specified
- Conditions
- Stroke
- Sponsor
- Emory University
- Enrollment
- 50
- Locations
- 1
- Primary Endpoint
- Change in stimulus response curve (SRC)
- Status
- Suspended
- Last Updated
- 2 years ago
Overview
Brief Summary
The goal of the study is to determine the effect of repetitive transcranial magnetic stimulation (rTMS) over the premotor cortex on training-related improvements in motor performance and associated neural plasticity.
Detailed Description
Motor training is an important part of recovery after stroke. During motor training, stroke patients practice performing a movement and become better at performing the trained movement over time. Repetitive transcranial magnetic stimulation (rTMS), which uses magnetism to excite neurons near the surface of the brain, may further improve performance. Healthy adults made larger training-related improvements in their motor performance when they received rTMS over the primary motor cortex during motor training. There is evidence that the premotor cortex may be a more effective target than the primary motor cortex for rTMS for some stroke survivors. In the current study, the investigator will determine the effect of rTMS over the premotor cortex on training-related improvements in motor performance in healthy adults.
Investigators
Cathrin Buetefisch
Associate Professor
Emory University
Eligibility Criteria
Inclusion Criteria
- •Motor training only (pilot participants):
- •Have the ability to give informed, written consent
- •Be aged 18-80 years old
- •Be right-handed using the Edinburgh handedness inventory
- •Have intact cognitive abilities (score higher than 75th percentile on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS))
- •No current depression (score less than 7 on the Hamilton Depression Rating Scale (HDRS))
- •No neurological disease
- •No contradictions to Transcranial Magnetic Stimulation (TMS)
- •TMS over the extensor carpi ulnaris (ECU) hotspot must evoke a motor evoked potential (MEP) in the ECU muscle
- •MEP amplitude must increase by at least 20% as the TMS intensity increases
Exclusion Criteria
- •Impaired cognitive abilities (score lesser than 75th percentile on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS))
- •Current depression (score more than 7 on the Hamilton Depression Rating Scale (HDRS))
- •Neurological disease
- •Has a contradiction to TMS
- •MEP cannot be evoked with TMS in the ECU muscle
- •Inability to tolerate one or more TMS strengths
Outcomes
Primary Outcomes
Change in stimulus response curve (SRC)
Time Frame: Baseline, post-motor training (1 minute, 30 minutes and 60 minutes after completion of motor training)
The stimulus response curve (SRC) is a set of motor evoked potentials (MEPs) collected in response to transcranial magnetic stimulation (TMS) pulses of increasing intensities. The SRC can characterize input-output parameters of the corticospinal tract and organization of the primary motor cortex. A change in the SRC parameters after training will reflect a change in the organization of the primary motor cortex associated with motor learning. We will compare the effect of the rTMS protocols on the change in the SRC parameters associated with motor learning (baseline to post 1 min, baseline to post 30 mins, baseline to post 60 mins).
Change in short interval intracortical inhibition (SICI)
Time Frame: Baseline, post-motor training (1 minute, 30 minutes and 60 minutes after completion of motor training)
Short interval intracortical inhibition (SICI) is an inhibitory phenomenon in the motor cortex. To test for SICI, a sub-threshold conditioning stimulus (CS) will precede a supra-threshold test stimulus (TS) by 2 milliseconds (ms). The amplitude of a conditioned TS-evoked MEP will be expressed as a percent of the amplitude of an unconditioned TS-evoked MEP. A decrease in the percent MEP after training would indicate a increase in SICI. An increase in the percent MEP after training would indicate a decrease in SICI. We will compare the effect of the rTMS protocols on the change in SICI associated with motor learning (baseline to post 1 min, baseline to post 30 mins, baseline to post 60 mins).
Change in wrist acceleration
Time Frame: Baseline, post-motor training (1 minute, 30 minutes and 60 minutes after completion of motor training)
The subjects will be asked to perform 7 isometric wrist extensions before and after motor training. Wrist acceleration will be measured by a gyroscope taped to the dorsum of the subject's hand undergoing motor training. An increase in the maximum acceleration that persists at least an hour after training is indicative of motor learning. We will compare the effect of the rTMS protocols on the change in the wrist acceleration associated with motor learning (baseline to post 1 min, baseline to post 30 mins, baseline to post 60 mins).
Secondary Outcomes
- Change in wrist force(Baseline, post-motor training (1 minute, 30 minutes and 60 minutes after completion of motor training))
- Change in reaction time(Baseline and post-motor training (1 minute, 30 minutes and 60 minutes after completion of motor training))
- Change in task accuracy(Baseline and post-motor training (1 minute after completion of motor training))