ÌÇÐÄvlog

Key Points

QuestionÌý What is the association between persistent postconcussion symptoms and overall health-related quality-of-life (HRQoL) in children following an acute concussion?

FindingsÌý This multicenter cohort study of children aged 5 to 18 years confirmed that those with persistent postconcussion symptoms had significantly lower global as well as physical, emotional, social, and school HRQoL subscores than did those without persistent postconcussion symptoms. Furthermore, even children whose symptoms resolved quickly reported lower school HRQoL subscores compared with published healthy norms through 12 weeks after head injury.

MeaningÌý Children with persistent postconcussion symptoms have lower HRQoL subscores compared with those who recovered from concussion, yet HRQoL deficits may persist for months even in children whose symptoms have resolved.

ImportanceÌý Persistent postconcussion symptoms (PPCS) pose long-term challenges and can negatively affect patients’ health-related quality of life (HRQoL). To date, no large comprehensive study has addressed the association between PPCS and HRQoL.

ObjectivesÌý To determine the association between HRQoL and PPCS at 4 weeks after concussion and assess the degree of impairment of HRQoL in the subsequent 12 weeks.

Design, Setting, and ParticipantsÌý In a prospective, multicenter cohort study (Predicting Persistent Postconcussive Problems in Pediatrics [5P]) from August 14, 2013, to September 30, 2014, children aged 5 to 18 years who presented to the emergency department within 48 hours after head injury and were considered to have an acute concussion were enrolled across 9 pediatric emergency departments within the Pediatric Emergency Research Canada Network. Persistent postconcussion symptoms were defined as 3 or more persistent symptoms on the validated Post-Concussion Symptom Inventory at 4 weeks. Linear mixed effects random coefficients models evaluated the association between PPCS and HRQoL, adjusting for potential confounders including age, sex, prior concussions, migraine, anxiety, learning disability, depression, and sleep disorder.

Main Outcomes and MeasuresÌý The primary outcome was HRQoL assessed with the validated Pediatric Quality of Life Inventory version 4.0 (PedsQL-4.0) at 4, 8, and 12 weeks after head injury.

ResultsÌý Of 2006 children enrolled (median age, 11.8 years [interquartile range, 8.9-14.6 years]; 1241 boys and 765 girls), 1667 (83.1%) completed the PedsQL-4.0 at all 3 time points. Of these 1667 children, the 510 with PPCS (30.6%) had lower total PedsQL-4.0 scores (mean, 70.0) than did those without PPCS (mean, 80.3; mean difference, –10.3; 95% CI, −9.4 to −11.2). Patients with PPCS also had significantly lower physical, emotional, social, and school PedsQL-4.0 subscores at 4, 8, and 12 weeks. Patients with PPCS had lower HRQoL than published healthy norms at 4 weeks (mean difference, 13.89; 95% CI, 11.55-16.23), 8 weeks (mean difference, 11.63; 95% CI, 9.34-13.93), and 12 weeks (mean difference, 9.38; 95% CI, 7.01-11.75; P &±ô³Ù; .001). Patients who recovered from concussion also had lower HRQoL than norms at 4 weeks (mean difference, 3.56; 95% CI, 1.28-5.85) and 8 weeks (mean difference, 2.75; 95% CI, 0.48-5.02; P &±ô³Ù; .05). School functioning PedsQL-4.0 subscores were significantly lower for all children regardless of PPCS status at all time points.

Conclusions and RelevanceÌý Children with PPCS have lower HRQoL compared with those who have recovered from concussion, yet deficits in HRQoL are pervasive across all domains and may persist for months even in children whose symptoms have resolved. Future interventional research should target the effect of concussion on HRQoL.

Concussion is a major public health concern in children.^1-3 Although many children recover quickly, approximately 30% experience persistent postconcussion symptoms (PPCS) for at least 1 month⁴ to years after head injury, which may lead to significant functional morbidity.^5,6The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision defines PPCS as an increase from perceived preconcussion baseline of 3 or more concussion symptoms at 28 days following the injury.⁷ Persistent postconcussion symptoms can include ongoing physical symptoms, cognitive problems, decreased mood, and behavior changes.⁶ Prolonged symptoms after a concussion may detrimentally affect participation in academic and recreational activities, thereby reducing social interactions.^6,8,9 Lower educational attainment and employment status have been identified in young adults who experienced concussion as children.¹⁰ As a result, PPCS may pose long-term challenges, thus reducing health-related quality of life (HRQoL),⁶ a multidimensional concept representing one’s perceived health status.

Several studies have shed light on pediatric HRQoL following head injuries. Strong associations exist between moderate to severe traumatic brain injury (TBI) and lower HRQoL, particularly in psychosocial functioning (eg, emotional, social, and school), compared with individuals who experienced only orthopedic injuries.^11,12 A limited number of studies have addressed HRQoL in patients with mild TBI, suggesting that PPCS is associated with lower physical and psychosocial HRQoL up to 12 months after injury, as well as an increased need for educational interventions.^6,13,14 Despite these important findings, previous studies are limited by small sample sizes and lengthy intervals between concussion and enrollment into the study (introducing potential selection bias toward patients with chronic concussion). Therefore, large comprehensive studies are warranted to address the association between PPCS and HRQoL as a function of the recovery timeline.¹⁵ Ultimately, better understanding of children’s outcomes after concussion is needed to provide an improved standard of care focusing on the patient’s physical, mental, and social well-being.¹⁶

The primary objective of this study was to determine the association between PPCS and HRQoL at 4 weeks after concussion in children aged 5 through 18 years. We hypothesized that HRQoL would be significantly lower at 4 weeks in children with PPCS than in children without PPCS. We had the following 3 secondary objectives: (1) evaluating the progression of global HRQoL and its subcomponents (physical, emotional, social, and school), (2) comparing HRQoL of both PPCS and non-PPCS groups with published healthy norms, and (3) identifying independent associations of change in overall HRQoL from 4 to 12 weeks after concussion.

This was a planned secondary analysis of data from the Predicting Persistent Postconcussive Problems in Pediatrics (hereafter to be referred to as 5P) study conducted from August 14, 2013, to September 30, 2014; the protocol¹⁷ and clinical prediction score for PPCS⁴ have been previously published.

The study uses the same inclusion and exclusion criteria as the 5P protocol.¹⁷ Participants recruited were children aged 5 through 18 years who presented to the emergency department (ED) within 48 hours after head injury and were considered to have a concussion as defined by Zurich criteria.¹⁸ Children were excluded if they had any of the following: Glasgow Coma Scale score of 13 or less; abnormal neuroimaging findings; a need for neurosurgical operative intervention, intubation, or intensive care; multisystem injuries requiring hospital admission, operating room, or procedural sedation; severe chronic neurologic developmental delay; or intoxication.

Participants were enrolled from the EDs of the following 9 Canadian pediatric hospitals within the Pediatric Emergency Research Canada Network: Izaak Walton Killam Health Centre, Halifax, Nova Scotia; Centre Hospitalier Universitaire Ste.-Justine, Montreal, Quebec; Montreal Children’s Hospital, McGill University Health Centre, Montreal, Quebec; Children’s Hospital of Eastern Ontario, Ottawa, Ontario; The Hospital for Sick Children, Toronto, Ontario; Children’s Hospital of Western Ontario, London, Ontario; Children’s Hospital of Winnipeg, Winnipeg, Manitoba; Stollery Children’s Hospital, Edmonton, Alberta; and Alberta Children’s Hospital, Calgary, Alberta. These EDs have a combined annual census of approximately 500 000 patient-visits. The research ethics committee at each participating institution approved the study.

Details of patient recruitment are outlined in the published 5P protocol.¹⁷ Briefly, children presenting to the ED with a head injury were considered to be potentially eligible for the study. Trained research assistants screened patients for eligibility; families that qualified were approached for and provided written consent in all cases and patient assent where applicable.

With help from research assistants, participants answered questions in electronic survey format in their first language (English or French) using a portable tablet computer. In addition to questions about patient demographics, parents completed the Acute Concussion Evaluation, a 22-item dichotomous validated tool used to objectively help diagnose concussion (as indicated by ≥1 symptoms on the Acute Concussion Evaluation).¹⁹ Data were further collected on injury characteristics, history (prior concussion, headache, and developmental or psychiatric disorder), and presenting symptoms (physical, emotional, cognitive and sleep) through the Post-Concussion Symptom Inventory (PCSI).^20,21

Participants were contacted at 1, 2, 4, 8, and 12 weeks after head injury (eTable 1 in the Supplement) by either an automated follow-up web survey using Research Electronic Data Capture or a telephone follow-up survey. In the event that participants did not complete the electronic survey within 24 hours of receipt, a second email was sent. If there was still no response, the family was contacted by telephone for an interview. The follow-up questionnaires included the PCSI at all follow-up dates and the Pediatric Quality of Life Inventory version 4.0 (PedsQL-4.0) at 4-, 8-, and 12-week follow-up.

The primary outcome measure was the total score on the PedsQL-4.0, a reliable and valid measure of HRQoL in healthy children and those with acute and/or chronic health conditions.²² Parent versions exist for children aged 2 to 18 years (in 4 age groups) and child versions exist for those 5 years or older. Patients 8 years or older completed the child PedsQL-4.0, while parents of children aged 5 through 8 years completed the parent version. Items are calculated and transformed into an overall score with a range of 0 to 100 points, with more points indicating better HRQoL. Secondary outcomes included the PedsQL-4.0 subscale scores: physical, emotional, social, and school (8, 5, 5, and 5 items, respectively). The self-report PedsQL-4.0 normative scores for a healthy child²³ are as follows: mean total, 83.9; physical, 87.7; emotional, 79.2; social, 84.9; and school, 81.3.

The PCSI was used to measure the persistence and severity of symptoms. The PCSI is a valid and reliable set of symptom scales for parents (20 items on a 7-point Likert scale) and children aged 5 to 7 years (13 items on a 3-point scale), 8 to 12 years (17 items on a 3-point scale), and 13 to 18 years (21 items on a 7-point scale), with excellent internal consistency and interrater agreement.^20,21 The PCSI measures symptoms in physical, cognitive, emotional, and sleep domains. Symptoms were defined as the absolute difference between the current self-reported PCSI ratings and those from before the injury. To be considered as having PPCS, patients were required to have a positive minimum 1-point change for 3 or more symptoms.^4,17

The primary objective of this study was to determine the association between HRQoL and PPCS at 4 weeks after concussion. Health-related quality of life was calculated using scoring instructions for the PedsQL-4.0. Descriptive statistics were used to summarize the data. Differences between patients who completed the PedsQL-4.0 and PCSI and those who did not were compared at each time point using χ² and Mann-Whitney tests where appropriate. Variables associated with HRQoL (total score) were identified by using parametric and nonparametric tests (t tests and Wilcoxon rank sum tests). For the primary outcome, linear mixed effects random coefficient models were used to evaluate the association between PPCS and HRQoL over time, adjusting for variables associated with univariate analyses or supported by observations from clinical practice. This method resulted in a model with fixed effects of PPCS, time, interaction of PPCS with time, age, sex, previous concussion, duration of previous concussion symptoms, prior treatment for headache, personal history of migraines, learning disability, anxiety, depression, and sleep disorder. The mixed effects procedure avoids listwise deletion owing to missing data. Next, the estimated marginal means at each time point were compared with the child self-report mean total score from a sample of healthy children²³ using a z test with correction for multiple comparisons using the Holm method. Secondary analyses examining the association between PPCS and the PedsQL-4.0 subscale scores (physical, emotional, social, school) were conducted identically. All analyses were performed using SPSS, version 21 (IBM Corp), and R, version 3.0.2 (R Project for Statistical Computing). All P values were 2-sided, and P < .05 was considered statistically significant.

Of the 5229 patients screened for eligibility, 2006 children were enrolled, of which 1667 (83.1%) completed the primary outcome survey at 4 weeks (eFigure in the Supplement). Of these 1667 children, 510 (30.6%) had PPCS at 4 weeks after injury. Table 1 describes the enrolled patients’ baseline characteristics. Minimal differences were found between patients who did and did not complete the PedsQL-4.0 and PCSI (eTable 2 in the Supplement). Participants with attention-deficit disorder or attention-deficit/hyperactivity disorder were less likely to respond at 8 weeks (77% vs 84%) and 12 weeks (72% vs 78%; P = .05), and participants with a history of 2 or more concussions were less likely to respond at 12 weeks (72% vs 79%; P = .04).

For our primary outcome, at 4 weeks, children with PPCS had a significantly lower PedsQL-4.0 total score than did children without PPCS (70.0 vs 80.3; mean difference, –10.3; 95% CI, –9.4 to –11.2). Lower PedsQL-4.0 total score in the PPCS group persisted at each follow-up time point compared with the group without PPCS. The mean difference in PedsQL-4.0 total score between the groups was –8.9 (95% CI, −8.2 to −9.6) at 8 weeks and –7.4 (95% CI, −6.5 to −8.4) at 12 weeks. Figure 1 displays the estimated marginal means from the model, as well as the progression of PedsQL-4.0 total scores over time for the groups with and without PPCS.²³ Although both groups showed increases in PedsQL-4.0 total scores over time (β = 0.56; 95% CI, 0.43-0.70; P < .001), the scores for the PPCS group increased faster than did the scores for the group without PPCS from 4 to 12 weeks after concussion, as reflected in a significant interaction of PPCS with time (β = 0.36; 95% CI, 0.21-0.51; P &±ô³Ù; .001).

Figure 2 displays the PedsQL-4.0 subscale scores (physical, emotional, social, and school) of children with and without PPCS at 4, 8, and 12 weeks of follow-up.²³ The PPCS group scored significantly lower on all subscales compared with the group without PPCS. This finding was consistent at each follow-up point (weeks 4, 8, and 12) for all subscales (Table 2).²³

Using published healthy norms, we compared the total and subscale PedsQL-4.0 scores for all patients with concussion (both those with and without PPCS). The estimated marginal means of patients with PPCS were significantly lower than the healthy population mean of 83.9 at 4, 8, and 12 weeks (eTable 3 in the Supplement). Patients without PPCS had significantly lower estimated marginal means than the healthy population mean at weeks 4 and 8, but not at week 12 (eTable 3 in the Supplement). Compared with published norms, children with PPCS scored significantly lower than healthy children at every time point for the physical, emotional, and school subscales (eTable 3 in the Supplement). Children with PPCS scored lower on the social subscale at 4 weeks but not at 8 or 12 weeks (eTable 3 in the Supplement). In comparison, children without PPCS did not have significantly lower physical, emotional, or social scores compared with healthy children at any of the time points (eTable 3 in the Supplement). However, scores on the school subscale were significantly lower (eTable 3 in the Supplement) for children without PPCS at all time points.

Finally, we examined factors significantly associated with lower overall HRQoL. Variables associated with lower HRQoL during 3 months included female sex, previous concussion, history of migraine, learning disability, and anxiety disorder (Table 3).

Children with PPCS report significantly lower overall HRQoL for up to 12 weeks after concussion when compared with children whose symptoms resolve within the first 4 weeks after injury. The detriments to HRQoL are pervasive across all domains (physical, emotional, social, and school functioning). All children with concussion (regardless of duration of symptoms after injury) have significantly lower HRQoL compared with published norms. Furthermore, even children who reported resolution of symptoms exhibited prolonged declines in HRQoL relative to healthy norms owing primarily to detriments in school functioning. However, both the HRQoL in children with and without PPCS improved over time.

Results of our study are consistent with those of smaller studies reporting decrements in the HRQoL of children following concussion. Moran et al¹³ concluded that higher initial symptom burden puts patients at risk for lasting declines in HRQoL and thus suggest that PPCS may be a target for improving HRQoL. Furthermore, Ransom et al²⁴ determined that symptomatic children and their parents report greater difficulties at school after concussion than their nonsymptomatic counterparts. Similarly, children who were no longer symptomatic after concussion also had school difficulties, with nearly half reporting diminished academic skills and trouble in at least 1 class during their recovery. These results are supported by our findings, which established that even asymptomatic children reported lower PedsQL-4.0 school functioning compared with healthy norms for at least 12 weeks after head injury. Our results indicate that school functioning is the last domain of HRQoL to resolve in both children with PPCS and those with concussion but without PPCS.

There are several hypotheses for the delayed effect of concussion on school functioning in children with PPCS and those without PPCS. First, our results may reflect a direct cognitive effect of concussion on pediatric HRQoL. A second hypothesis involves an epiphenomenon of the injury situation. As a student recovers from a concussion, schoolwork begins to accumulate, which may be stressful for certain children. After the student has largely recovered, completing the accumulated work takes time, and some children still feel this stress when no other symptoms are present. Therefore, their school HRQoL reports may reflect the effect of this stress. Third, our baseline school measure did not differentiate between quality of school functioning before and after the concussion. Therefore, it is possible that reports of school difficulties may be associated with those already present before the concussion.

Comparing our findings with those of other studies reporting on HRQoL among children with chronic illness provides insight into the potential effect of concussion on HRQoL. For instance, 1 month after hematopoietic stem cell transplantation, children report a mean total PedsQL-4.0 score of 74, similar to that in our overall concussion cohort.²⁵ Children with PPCS reported a lower HRQoL than that reported by children with type 1 diabetes, whose PedsQL-4.0 scores are similar to those in our group without PPCS.²⁶ Furthermore, both children with and without PPCS scored below healthy norms on the PedsQL-4.0 school functioning subscale, which seems to be the subscale most affected by chronic health conditions.²³

Several studies have examined independent associations with poor HRQoL after concussion. For instance, Scholten et al,²⁷ in a cohort of adults with mild, moderate, and severe TBI, identified female sex and medical comorbidities as the strongest associations with decreased HRQoL at 6 and 12 months after TBI. Furthermore, pediatric patients with TBI exhibited improvement in the initial 3 to 24 months after injury compared with their baseline PedsQL-4.0 results²⁸; however, significant long-term HRQoL impairments remained without further improvement from 24 to 36 months.²⁹ Significant associations of poor functioning after pediatric mild TBI included lower parental education, Hispanic race/ethnicity, low household income, and Medicaid insurance.³⁰ Additional studies have found that repeated concussions may lead to greater cognitive dysfunction and neuropsychiatric conditions, which themselves can negatively affect pediatric HRQoL.^31,32 Furthermore, female sex, previous TBI, and neurologic and psychological illness were associated with PPCS in both children and adults.^33-35 Female sex and prior concussion were also identified in our study, along with migraine history, learning disability, and/or anxiety disorder as independently associated with overall HRQoL decrement in children after concussion.

The study has several strengths that contribute to the validity of our results. First, to our knowledge, this is the largest prospective multicenter study to date examining the effect of pediatric concussion on HRQoL. We collected a large sample from a geographically diverse population from pediatric hospitals across Canada, with participants being included despite preexisting behavioral, learning, or psychological problems. By excluding patients presenting more than 48 hours after head injury, we ensured that our results are applicable to any child presenting for acute concussion assessment and not biased toward those presenting with persisting symptoms. Our data are bolstered by the standardization of training for all research staff. Furthermore, we used validated outcome variables and achieved excellent follow-up rates.

This study has several potential limitations. First, we did not include a control group, and thus we are unable to directly attribute PPCS and its effect on HRQoL to concussion. However, we did compare our results with published normative data. Second, we used only self-report for assessing both PPCS and HRQoL in the group 8 years or older, introducing shared rater variance. However, parent-child agreement regarding PPCS and HRQoL is only moderate, so using different raters might underestimate the association of PPCS with HRQoL.^19,36 Moreover, as we included only children with concussions who presented to the ED within 48 hours of their injury, our results may not be generalizable to those presenting with delayed-onset symptoms, those not seeking care, or seeking care outside the ED (as only few children with concussion may seek ED care).³⁷ Patients in the ED may be primed to have lower HRQoL and/or higher risk of PPCS, but since we did not collect baseline PedsQL-4.0 assessments, we were unable to assess their HRQoL before injury. This fact, plus our nontrial study design, precluded our ability to determine causality. Future research should examine if PPCS leads to poor HRQoL or vice versa, with subsequent interventions targeting the root cause.

Children with PPCS had significantly lower total, physical, emotional, social, and school quality of life that persisted for at least 12 weeks after concussion than did children with no PPCS. Overall, both patients with and without PPCS with concussion report declines in overall and school quality of life relative to healthy norms.²³ Finally, the following independent associations with HRQoL decrement in children after concussion were identified: female sex, having a previous concussion, history of migraine, learning disability, or anxiety disorder. Results from our study provide insight into the psychosocial burden of pediatric concussion and may help identify patients and families requiring extra support or guidance regarding management of expectations and coping mechanisms after concussion. Finally, our results will help guide future interventions to reduce the effect of concussion on HRQoL.

Knowledge translation and mobilization is an important next step to ensure that parents, teachers, school administrators, and educational boards are aware of the effect of concussion on children’s HRQoL in school. Health care professionals should identify patients and families at higher risk for PPCS and decreased HRQoL.

Accepted for Publication: July 28, 2016.

Corresponding Author: Roger L. Zemek, MD, Children’s Hospital of Eastern Ontario Research Institute, 401 Smyth Rd, Ottawa, ON K1H 8L1, Canada (rzemek@cheo.on.ca).

Published Online: October 24, 2016. doi:10.1001/jamapediatrics.2016.2900

Author Contributions: Dr Zemek had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Aglipay, Gravel, Freedman, Gagnon, Gioia, Boutis, Burns, Osmond, Zemek.

Acquisition, analysis, or interpretation of data: Novak, Aglipay, Barrowman, Yeates, Beauchamp, Gravel, Freedman, Gagnon, Gioia, Boutis, Burns, Ledoux, Zemek.

Drafting of the manuscript: Novak, Aglipay, Boutis, Zemek.

Critical revision of the manuscript for important intellectual content: Novak, Aglipay, Barrowman, Yeates, Beauchamp, Gravel, Freedman, Gagnon, Gioia, Burns, Ledoux, Osmond, Zemek.

Statistical analysis: Aglipay, Barrowman.

Administrative, technical, or material support: Gravel, Freedman, Gioia, Ledoux, Zemek.

Study supervision: Beauchamp, Gravel, Freedman, Gagnon, Boutis, Zemek.

Conflict of Interest Disclosures: Dr Gioia reported being the author of the Postconcussion Symptom Inventory (PCSI); the PCSI is freely available and he receives no financial benefit for its use. No other conflicts were reported.

Funding/Support: This study was supported by operating grant TM1 127047 from the Canadian Institutes of Health Research and grant 126197 from the Canadian Institutes of Health Research–Ontario Neurotrauma Foundation Mild Traumatic Brain Injury Team. Preliminary work was funded by planning grant MRP 119829 from the Canadian Institutes of Health Research.

Role of the Funder/Sponsor: The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Group Information: The Pediatric Emergency Research Canada Predicting Persistent Post-concussive Problems in Pediatrics (PERC 5P) Concussion Team includes Candice McGahern, BA (Children’s Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada); Gurinder Sangha, MD (Department of Pediatrics, Children’s Hospital of Western Ontario, Western University, London, Ontario, Canada); Darcy Beer, MD (Department of Pediatrics, Manitoba Children’s Hospital, Winnipeg, Manitoba, Canada); William Craig, MDCM (Department of Pediatrics, Stollery Children’s Hospital, Edmonton, Alberta, Canada); Ken J. Farion, MD (Department of Pediatrics, Children’s Hospital of Eastern Ontario, University of Ottawa, Ottawa, Canada); Angelo Mikrogianakis, MD (Department of Pediatrics, Alberta Children’s Hospital, Calgary, Alberta, Canada); Karen Barlow, MD (Department of Pediatrics and Clinical Neurosciences, Alberta’s Children’s Hospital, University of Calgary, Calgary, Canada); Alexander S. Dubrovsky, MDCM, MSc (Department of Pediatrics, Montreal Children’s Hospital, McGill University Health Center, Montreal, Quebec, Canada); Willem Meeuwisse, MD, PhD (Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Canada); William P. Meehan III, MD (Sports Concussion Clinic, Boston Children’s Hospital, Boston, Massachusetts); Yael Kamil, BSc (Children’s Hospital of Eastern Ontario Research Institute, Ottawa, Canada); Anne M. Grool, MD, PhD, MSc (Children’s Hospital of Eastern Ontario Research Institute, Ottawa, Canada); Blaine Hoshizaki, PhD (Department of Kinesiology, University of Ottawa, Ottawa, Canada); Peter Anderson, PhD (Department of Psychology, Children’s Hospital of Eastern Ontario, Ottawa, Canada); Brian L. Brooks, PhD (Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, Canada); Michael Vassilyadi, MDCM, MSc (Department of Neurosurgery, Children’s Hospital of Eastern Ontario, Canada); Terry Klassen, MD (Department of Pediatrics, Manitoba Children’s Hospital, Winnipeg, Canada); Michelle Keightley, PhD (Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada); Lawrence Richer, MD (Department of Neurology, Stollery Children’s Hospital, Edmonton, Canada); and Carol DeMatteo, MSc (School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada).