mTBI Mechanisms of Action of HBO2 for Persistent Post-Concussive Symptoms

Post-Concussion Syndrome Clinical Trial

— BIMA  

Official title:

Brain Injury and Mechanisms of Action of HBO2 for Persistent Post-Concussive Symptoms After Mild Traumatic Brain Injury (BIMA) Protocol

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01611194
• Other study ID #: S-11-17
• Status: Completed
• Phase: Phase 2
• Start date: September 11, 2012
• Est. completion date: January 29, 2016

Study information

• Verified date: October 2018
• Source: U.S. Army Medical Research and Materiel Command
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Purpose of this study is to investigate the mechanisms of action of hyperbaric oxygen therapy for persistent post-concussive symptoms after mild tramatic brain injury

Description:

Active duty military personnel and Veterans received for 60-minute daily chamber sessions in which they received HBO2, 1.5 atmospheres absolute (ATA), or sham intervention (1.2 ATA, room air) for post concussion syndrome (PCS).

The study is to provide a rationale for the selection of outcome assessments to serve as primary and secondary endpoints for a pivotal randomized clinical trial of hyperbaric oxygen for the treatment of PCS. The participants will undergo a comprehensive battery of symptom and quality of life assessments. The distribution of response, change in response over time, homogeneity of variance across subgroups, and relationships between outcome measures will be compared by treatment assignment with a cohort from a study of similar design among a normal study population.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 71
• Est. completion date: January 29, 2016
• Est. primary completion date: January 2015
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria

• On active duty (TRICARE beneficiary) at the time of consent and through the 6-month visit or a Veteran, as well as Active Duty military who become Veterans after enrollment.

• Men and women 18-65 years of age at the time of study enrollment.

• Able to equalize middle ear pressure in a test of chamber pressure and tolerate the chamber environment.

• Able to speak and read English, as primary language.

• Agrees to and appears able to participate in all outcome assessments.

• Agrees to provide blood samples for clinical lab tests.

• Demonstrates the ability to offer informed consent and signs the study informed consent document.

• Participants stationed or living outside the Colorado Springs/Denver, Colorado area must be willing and able to travel. A reliable companion may accompany the participant if travel supervision is required.

• Active duty participants must obtain a letter of support from a supervisor or commanding officer prior to the outcome assessments (and travel, if necessary) to the OAC.

Participants must have a history of at least one (minimum requirement) mild traumatic brain injury (mTBI) with persistent symptoms that meets all the following criteria:

• Brain injury that occurred more than 3 months prior to baseline screening at the local site, with the most recent injury occurring no more than 5 years prior to randomization.

• Most recent traumatic brain injury (TBI) occurred on active duty.

• TBI was caused by non-penetrating trauma or blast exposure.

• TBI resulted in at least one of the following at the time of injury: a period of loss of or a decreased level of consciousness (up to 30 minutes); a loss of memory for events immediately before or after the injury (up to 24 hours); or alteration in mental state at the time of the injury (becoming dazed or confused).

• Has current complaints of TBI symptoms such as headache, dizziness, or cognitive or affective problems that score at least 3 post-concussive symptoms as assessed by the OSU TBI-ID.

• Has received current standard of care pharmacologic and nonpharmacologic interventions for TBI and any concomitant post traumatic stress disorder (PTSD) with no significant change in psychoactive therapy for at least 1 month.

• Creatinine level that is less than or equal to the EACH laboratory's upper limit of normal. If the creatinine level exceeds the EACH laboratory's upper limit of normal, participants cannot have a CT scan due to risk of contrast dye-induced renal failure. Such participants may be randomized but must be approved by the Study Director.

Exclusion Criteria:

• Prisoners.

• Pregnant Women.

• Minors.

• Individuals whose most recent TBI was sustained during illegal activity.

• Potential active duty participants stationed >1 hour outside the designated recruitment area of a participating local site will be excluded unless the command authorizes temporary relocation and appropriate relocation resources.

• Potential Veteran participants who live >1 hour outside the designated recruitment area of a participating local site, must be willing and able to travel to the local site to participate in all required local site visits without additional financial assistance than that which is described in the Veteran Payment Schedule (consent attachment C).

• Active duty individuals with anticipated prolonged TAD/TDY or deployment within 6 months of study enrollment will be excluded.

• Veterans with anticipated prolonged travel or relocation within 6 months of study enrollment will be excluded.

An individual with any of the following characteristics will be excluded from this study based on contraindications to hyperbaric pressurization and hyperbaric oxygenation or other study assessment measures:

• Women who are pregnant or who plan to become pregnant during the study period.

• Women who are breastfeeding.

• Women of childbearing potential who do not agree to practice an acceptable form of birth control during the study period.

• Epilepsy or seizure disorder not stable on anticonvulsant therapy (stable defined as 6 months seizure-free).

• Inability to protect airway or requires frequent suctioning.

• Known or suspected perilymphatic fistula.

• Presence of tracheostomy (due to limitations in autoinflation of the middle ear space).

• Diabetes (risk of hypoglycemia).

• Creatinine level that exceeds 1.5 times the EACH laboratory's upper limit of normal.

• A diagnosis (from patient report or medical record evidence within one year) of untreated clinical hypo- or hyperthyroidism.

• Allergy to iodine-based contrast dye (exclusion criteria for neuroimaging assessment measures only).

• Presence of implanted device (e.g., cardiac defibrillator, intrathecal drug delivery device, cochlear implant, pacemaker, stents or aneurysm clips) that poses increased risk to the participant during hyperbaric exposure or magnetic resonance imaging (MRI). Any implanted device must be cleared through the manufacturer for exposure to hyperbaric pressure and 3.0 Tesla MRI.

• Participants who must travel to altitudes greater than 10,000 feet during chamber session intervention.

• Paratroopers who are unable to suspend activity during chamber exposures.

• An individual who has had refractive eye surgery within the last 90 days.

• Any brain injury not of traumatic etiology, such as stroke or drug-induced coma.

• Heart failure with ejection fraction < 50% (due to increased risk for precipitating acute lung edema during exposure to HBO2).

• Emphysema, chronic bronchitis, or bullous lung disease (due to risk for pulmonary barotrauma during hyperbaric decompression).

• Asthma not well controlled.

An individual with any of the following characteristics will be excluded from this study based on confounding of the outcome measures:

• Those who are unable to participate fully in outcome assessments unless randomization is reviewed and approved (in writing) by the study director.

• Vision uncorrectable to 20/50 (monocular vision acceptable).

• Dynavision within 30 days of screening.

• Deafness in both ears defined as 90 dB HL or greater, through the speech frequencies of each of 500 Hz, 1 kHz, 2 kHz and 4 kHz in each ear; this is determined by a baseline measurement of pure tone air conduction thresholds.

• Participant self-report or documented diagnosis of psychiatric disorders in the medical record within the last year of any of the following: schizophrenia, dissociative disorder, or bipolar disease.

• Anxiety or claustrophobia precluding participation in the hyperbaric chamber sessions or neuroimaging procedures.

• Verifiable neurodegenerative disease (e.g., Alzheimer's disease, multiple sclerosis, senile dementia).

• Presence of chronic debilitating disease (e.g., end-stage renal disease, end-stage liver disease, diabetes with sequelae).

• Documented unresolved anemia, with anemia defined as hematocrit less than 30%.

• History, by self-report, of receiving therapeutic ionizing radiation to the head.

• Foreign material in head that would interfere with brain imaging (e.g., MRI or computed tomography [CT]), unless randomization has been cleared by the study director.

• Foreign (unknown composition) or metallic/ferromagnetic material within the individual that poses risk from MRI, unless randomization has been cleared by the study director.

• History, by self report, of illicit drug use, except remote (prior to military enlistment) non-habitual (habitual is considered greater than weekend) use of marijuana.

• History, by self report or medical record in the last year, of alcohol abuse. Prospective participants who have been sober for the last 90 days prior to screening may be eligible based on the site principal investigator determination.

• Current positive urine test for an illicit substance(s).

• Any condition or use of prescribed medication in which, in the opinion of the investigator, participation in this study would impact the safety of the individual.

• Brain injury of moderate or severe degree: duration of loss of consciousness at the time of injury greater than 30 minutes, duration of post-traumatic amnesia greater than 24 hours, or brain injury of a penetrating etiology.

• Any lifetime history of penetrating brain injury.

• Active malignancy, prior malignancy (except basal cell carcinoma) within the last 5 years, or any prior treatment with bleomycin (trade name Blenoxane). Prior treatment with doxorubicin (trade name Adriamycin) is acceptable as long as an echocardiography following treatment is normal.

• Unable to abstain from caffeine or tobacco products for at least a 2-hour interval.

• Concurrent enrollment in an alternate interventional trial.

• Unable or unwilling to cease participation in sports in which another head injury is likely (e.g., mixed martial arts, boxing) during the study period.

• Diagnosis of Meniere's disease by self-report or medical record evidence within one year.

• Pre-TBI history of significant dizziness (lasting more than 1 day).

A prospective participant with any of the following characteristics will be excluded from this study to protect blinding:

• Prior treatment with HBO2 for TBI or PCS.

• Prior HBO2 treatment for indications other than TBI or PCS within the last 3 months.

• Experienced hyperbaric chamber inside attendant (anyone deemed to have experience with hyperbaric pressurization that could compromise their blind to allocation).

• Technical, military, or occupational divers.

Related Conditions & MeSH terms

• Brain Injuries
• Brain Injuries, Traumatic
• Post-Concussion Syndrome
• Traumatic Brain Injury With Brief Loss of Consciousness
• Unconsciousness
• Wounds and Injuries

Intervention

Drug:
• Hyperbaric oxygen (HBO2) at 1.5 atms
The Hyperbaric oxygen (HBO2) at 1.5 atms (active) group (hyperbaric oxygen-chamber compressed to 1.5 atm abs and breathing 100% oxygen). Each participant should complete 40 sessions over the course of 12 weeks, one session per day, five per week.
• Sham control 1.2 atms
The chamber will be compressed with air to 1.2 atm abs to simulate the active group. Participants will don a hood and breathe 21% oxygen (room air). Each participant will complete 40 sessions, one session per day, five sessions per week, within 12 weeks following randomization. Breathing air at a pressure of 1.2 atm abs is equivalent to inhaling 25% oxygen at sea level pressure (1.0 atm abs).

Locations

Country	Name	City	State
United States	Outcomes Assessment Center, Evans Army Community Hospital	Colorado Springs	Colorado
United States	Evans Army Community Hospital / Hyperbaric Medicine Complex	Fort Carson	Colorado
United States	Joint Base Lewis-McChord	Fort Lewis	Washington
United States	Camp Lejeune	Jacksonville	North Carolina
United States	TBI Program/HBO2 Research Program Madigan Healthcare system	Tacoma	Washington

Sponsors (1)

Lead Sponsor	Collaborator
U.S. Army Medical Research and Materiel Command

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Summary of Treatment-Emergent Adverse Events	Safety was evaluated in-person during the first 3 months and at month 6, and via telephone follow-up calls at months 4, 5, and 7-12. Extended annual follow-up continued for up to 36 months through January 2016.	months 3, 6, 4, 5 and 7-12. Extended f/u up to 36 months
Primary	Summary of Study Intervention-Related Adverse Events	Safety was evaluated in-person during the first 3 months and at month 6, and via telephone follow-up calls at months 4, 5, and 7-12. Extended annual follow-up continued for up to 36 months through January 2016.	months 3, 6, 4, 5 and 7-12. Extended f/u up to 36 months
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ, RPQ3 and RPQ13) - Baseline (ITT Population)	RPQ/RPQ-3 was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-3 ranges from 0-12 and access a subset of symptoms. RPQ-13 ranges from 0-52 and access's 13 remaining symptoms. Analyses of the RPQ-3 and RPQ-13 domain scores are presented separately. For each of the RPQ-3, RPQ-13, and RPQ total scales, the scores were derived by totaling the corresponding question scores for each domain.	Baseline
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ, RPQ3 and RPQ13) - Baseline (Per Protocol (PP) Population)	RPQ/RPQ-3 was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-3 ranges from 0-12 and access a subset of symptoms. RPQ-13 ranges from 0-52 and access's 13 remaining symptoms. Analyses of the RPQ-3 and RPQ-13 domain scores are presented separately. For each of the RPQ-3, RPQ-13, and RPQ total scales, the scores were derived by totaling the corresponding question scores for each domain.	Baseline
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ) - Change From Baseline (ITT Population)	RPQ was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. The scores were derived by totaling the corresponding question scores for each domain and it's change from baseline.	Baseline to week 13, Months 6 and 12
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ3) - Change From Baseline (ITT Population)	RPQ-3 was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-3 ranges from 0-12 and access a subset of symptoms. Analyses of the RPQ-3 domain scores are presented separately. For the RPQ-3 total scales, the scores were derived by totaling the corresponding question scores for each domain and it's change from baseline.	Baseline to week 13, Months 6 and 12
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ13) - Change From Baseline (ITT Population)	RPQ was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-13 ranges from 0-52 and access's 13 remaining symptoms. Analyses of the RPQ-13 domain scores are presented separately. For RPQ-13 total scales, the scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to week 13, Months 6 and 12
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ) - Change From Baseline (Per Protocol (PP) Population)	RPQ was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-3 ranges from 0-12 and access a subset of symptoms. For the RPQ total scales, the scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to week 13, Months 6 and 12
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ3) - Change From Baseline (Per Protocol (PP) Population)	RPQ/RPQ-3 was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-3 ranges from 0-12 and access a subset of symptoms. For the RPQ-3total scale, the scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to week 13, Months 6 and 12
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ13) - Change From Baseline (Per Protocol (PP) Population)	RPQ was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". RPQ-13 ranges from 0-52 and access's 13 remaining symptoms. Analyses of the RPQ-13 domain scores are presented separately. The scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to week 13, Months 6 and 12
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ) - Change From Baseline: 24 and 36 Months (ITT Population)	RPQ was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. For the RPQ total scales, the scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to 24 months and 36 months
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ3) - Change From Baseline: 24 and 36 Months (ITT Population)	RPQ-3 was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-3 ranges from 0-12 and access a subset of symptoms. Analyses of the RPQ-3 domain scores are presented separately. For the RPQ-3 total scales, the scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to 24 months and 36 months
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ13) - Change From Baseline: 24 and 36 Months (ITT Population)	RPQ was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-13 ranges from 0-52 and access's 13 remaining symptoms. Analyses of the RPQ-13 domain scores are presented separately. For RPQ-13 total scales, the scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to 24 months and 36 months
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ) - Change From Baseline (Per Protocol (PP) Population)	RPQ was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. For the RPQ total scales, the scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to month 24 and month 36
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ3) - Change From Baseline (Per Protocol (PP) Population)	RPQ-3 was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-3 ranges from 0-12 and access a subset of symptoms. Analyses of the RPQ-3 domain scores are presented separately. For the RPQ-3 total scales, the scores were derived by totaling the corresponding question scores for each domain and change from baseline.	Baseline to month 24 and month 36
Secondary	Presence of Post Concussion Symptoms Following Traumatic Brain Injury Using The Rivermead Post-Concussion Symptom Questionnaire (RPQ13) - Change From Baseline (Per Protocol (PP) Population)	RPQ was created to measure the severity of post-concussion symptoms following traumatic brain injury. Scale compares any current symptoms to pre-injury levels to account for potential symptom exacerbation due to the TBI. The RPQ is the most commonly used clinical measure for mild TBI research because it is simple and reflects psychosocial function. The RPQ is intended to measure the presence and severity of 16 of the most commonly reported post-concussion symptoms found in the literature. The RPQ scale includes 16 common post-concussion symptom items whose responses range from "0= Not experienced at" to "4= A severe problem". Total range is 0 to 64. RPQ-13 ranges from 0-52 and access's 13 remaining symptoms. Analyses of the RPQ-13 domain scores are presented separately. For RPQ-13 total scales, the scores were derived by totaling the corresponding question scores for each domain change from baseline.	Baseline to month 24 and month 36