Brain Stimulation During Arm Immobilisation

Study Overview
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Brief Summary
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The research project explores how non-invasive brain stimulation can be used to detect and ameliorate loss of muscle strength after inactivity. At present, there is a limited understanding of how to maintain muscle strength during inactivity. Increasing evidence indicates that reduction in muscle strength following immobilisation is associated with reduced cortical motor output. Therefore, the aim of the study is to test if brain stimulation, can maintain cortical motor output and ameliorate the loss of muscle strength following immobilisation.

Official Title
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Exercising the Motor Cortex Using Brain Stimulation

Conditions
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Muscle Loss

Intervention / Treatment
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* Other: Transcranial Magnetic Stimulation (TMS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male right-handed aged 18-30 healthy BMI Exclusion Criteria: no primary muscle disorders no open wounds or skin conditions to arms and hands no neurological disorders or history of no history of fainting/convulsions no metal implanted into head/eye/neck non-smoker no arm, hand, fingers, shoulder injuries

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: TMS<br>Six 30-pulse trains of 20 Hz repetitive Transcranial Magnetic Stimulation to left primary motor cortex hand area, separated by 60 seconds, repeated at 0, 24, 48, and 72 hours post-immobilisation. | Other: Transcranial Magnetic Stimulation (TMS)<br>* TMS is a safe and non-invasive technique, which involves the generation of brief magnetic pulses applied to the head through a coil. The magnetic pulses pass through the scalp and skull and induce weak electric currents in the neural tissue directly underneath the coil. When TMS is applied in repetitive, patterned trains of pulses (rTMS), it can induce cortical plasticity specifically in the targeted brain region.<br>|
| Sham Comparator: Sham<br>Six 30-pulse trains of 20 Hz repetitive sham Transcranial Magnetic Stimulation above, but not in contact with, the head, separated by 60 seconds, repeated at 0, 24, 48, and 72 hours post-immobilisation. | Other: Transcranial Magnetic Stimulation (TMS)<br>* TMS is a safe and non-invasive technique, which involves the generation of brief magnetic pulses applied to the head through a coil. The magnetic pulses pass through the scalp and skull and induce weak electric currents in the neural tissue directly underneath the coil. When TMS is applied in repetitive, patterned trains of pulses (rTMS), it can induce cortical plasticity specifically in the targeted brain region.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Motor Evoked Potentials (MEPs) across time points | MEPs are elicited via TMS to primary motor cortex and index the excitability of the motor pathway. They are recorded non-invasively from muscles using surface electrodes. At each time point of the study (0, 24, 48, 72 hours) record MEPs will be recorded pre and post-intervention from the hand muscles of the dominant (immobilised) arm, and non-dominant (non-immobilised arm), to evaluate changes in excitability. Specifically, the peak-to-peak value of the MEPs from the hand will be measured, which reflects the amplitude of the MEP response. The latency of the MEP to index neural conduction speed will also be measured. | 0, 24, 48, and 72 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in grip strength across time points | Grip strength of the dominant and non-dominant hands will be assessed using an isokinetic dynamometer at 0 and 72 hrs post-immobilisation. This will measure the strength of the hand muscles. | 0, and 72 hours. |