Cortical Plasticity Assessment in Athletes With a History of Concussion

Study Overview
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Brief Summary
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The purpose of this research is to determine whether athletes with concussion have changes in cortical excitability. Single and paired transcranial magnetic stimulation (TMS) can be used as reliable neurophysiological marker of motor cortex reorganization in athletes with concussions. This study also aims to determine whether modulation of cortical activity by a powerful technique of noninvasive brain stimulation (tDCS) results in a different cortical response as compared with sham tDCS.

Detailed Description
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This study is a multicenter study with investigators from other institutions (Dr. Alvaro Pascual-Leone and Dr. Hugo Theoret).

Official Title
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Cortical Plasticity Assessment in Athletes With a History of Concussion

Conditions
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Concussion

Intervention / Treatment
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* Device: Transcranial direct current stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Student-athletes at risk for traumatic brain injury (collegiate football, ice hockey) Age between 18 and 30 yr. Concussion as defined by the American Academy of Neurology: trauma-induced alteration in mental status that may or may not involve loss of consciousness (confusion and amnesia are the hallmarks of concussion) Concussion that occurred > 6 months All head injuries classified as minor with a Glasgow Coma Scale of 13 to 15 at the time of the trauma Participants are cleared for full sport participation based upon neurological and neuropsychological (NS) assessments Classified as symptomatic based on Post-concussion Symptom List Exclusion Criteria: Previous significant neurological history Use of tricyclic anti-depressants such as amitriptyline, nortriptyline and imipramine within the past six months. Use of anticonvulsants such as carbamazepine, phenytoin, valproic acid and gabapentin within the past six months History of seizures, depression or PTSD Presence of post-concussion symptoms such as complaints of loss of concentration, dizziness, fatigue, headache, irritability, visual disturbances, and light sensitivity. Contraindications to single pulse TMS (TMS will be used to measure cortical excitability) such as metal head implants history of seizures unexplained loss of consciousness metal in the head frequent or severe headaches or neck pain implanted brain medical devices. Contraindications to tDCS: metal in the head implanted brain medical devices For the control group (subjects with no concussion) we will select subjects according to the previously stated list of exclusions as well as the following criteria: Subjects who are athletes (similar to the concussed group) with the same age range and also similar level of education; however these subjects will have no prior history of concussion or neurological insult as self reported. They should also have no contraindications to TMS or tDCS.

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

Sexes Eligible for Study
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All

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: Non-Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Healthy Subjects<br>Each subject will undergo each of the three conditions (active anodal tDCS, cathodal tDCS and sham tDCS), but the order in which they do so will be randomized. | Device: Transcranial direct current stimulation<br>* Each type of stimulation will be administered with a time interval of a week in between to prevent any carryover affects.<br>|
| Experimental: Athletes with history of concussion<br>Each subject will undergo each of the three conditions (active anodal tDCS, cathodal tDCS and sham tDCS), but the order in which they do so will be randomized. | Device: Transcranial direct current stimulation<br>* Each type of stimulation will be administered with a time interval of a week in between to prevent any carryover affects.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cortical excitability and cortical plasticity assessment | TMS and tDCS | Baseline, 1st, 2nd and 3rd week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cognitive functioning in athletes with concussion compared to athletes without concussion | Will use the Immediate Postconcussion Assessment and Cognitive Test (IMPACT): a neuropsychological test battery that measures aspects of cognitive functioning including attention, memory, reaction time and information processing speed. | Baseline, 1st, 2nd and 3rd week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Athletes, Multiple Concussions, Transcranial Stimulation