Sport Originated Brain Injury: An Update for PhysiotherapistsSPRINZ

Joshua McGeown 1 , Patria Hume 1,2 Natalie Hardaker 3,1 1 Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New

Zealand; 2 National Institute for Stroke and Applied Neuroscience Research, Auckland University of Technology, Auckland, New Zealand; 3 Accident Compensation Corporation

Sport originated brain injury (SOBI) is a growing area of concern to the public, media, clinicians and researchers. Approximately 30% of athletes who sustain a SOBI will experience protracted symptom resolution characterised by one or more post-concussion disorders. A proportion of patients with SOBI require attention from physiotherapists with specialty training in the identification and treatment of cervical and/or vestibulo-ocular pathologies. Physiotherapists play a crucial role in the management of SOBI. We call upon physiotherapists and sports physicians to discuss how we can improve early identification of the predominant symptom cluster and develop therapy protocols that can be individualised for SOBI patients.

KEYWORDS: concussion, mild traumatic brain injury, assessment, rehabilitation, return to

play, return to learn.

Severity of traumatic brain injury (TBI) can range from mild concussion to a severe penetrating injury resulting in coma or death [1]. In New Zealand, approximately 21% of all reported TBIs were sustained while playing sport or during physical activity [2]. Of these TBIs 98% were considered mild TBIs, and 51% of these were sustained by youth under the age of 18 years old [2]. Sport Related Concussion (SRC) and mild Traumatic Brain Injury (mTBI) are often used interchangeably both in the literature and in clinical practice. It is important to understand that concussion is a subset of mTBI and therefore not all mTBIs are necessarily concussion [3].

To improve the understanding of the seriousness of any brain injury that can result from sport, and to improve clarity surrounding the implications of mTBI and SRC resulting from sporting activities, we have coined the easily remembered abbreviation SOBI for sport originated brain injury. SOBI describes the mechanical loading and deformation of brain tissue [1] that occurs as a result of impacts to the head or body and transmitted to the head that can occur during sport participation. This loading results in the brain colliding with the inside of the skull, and triggers a complex pathophysiological process causing disruption to normal brain function and metabolism which manifests clinically with somatic, cognitive, and emotional symptoms[5, 6] reported by the patient, and signs observed by clinicians [3-5].

*CONTINUED >> Following SOBI, approximately 70% of individuals will experience spontaneous resolution of their symptoms within 10-14 days after the initial mechanical injury took place [6]. Conversely, other evidence indicates that 20-40% of individuals sustaining SOBI may continue to experience

persistent symptoms for weeks, months, or years

after the initial injury [7, 8]. It was hypothesised that persistent symptoms beyond the acute period of SOBI were a result of unresolved global physiological dysfunction due to the initial forces applied to the brain [9].

A classification system for persistent symptoms was proposed to stratify individuals into one of three predominant symptom cluster (PSC) subgroups [9- 12]. 1. Vestibulo-ocular PSC includes persistent symptoms such as dizziness, postural instability, or blurry vision caused by dysfunction of the vestibulo-ocular system due to the initial SOBI [9].

Cervicogenic PSC includes persistent concussion symptoms such as neck pain, lightheadedness, or occipital headaches caused by injury and dysfunction of the cervical spine somatosensory system due to the initial forces causing SOBI [9].

Physiologic PSC includes persistent symptoms such as difficulty concentrating, memory loss, fatigue, or exercise intolerance and is associated with impaired brain metabolism and autonomic function [9].

This method of classification provides clinicians and researchers a means to assess and differentiate between which PSC is underlying the majority of symptoms. Individuals with SOBI would be expected to present with symptoms attributed to more than one PSC. Nevertheless, there is still limited evidence regarding the ideal clinical model for the management of SOBI.

Physiotherapists play a crucial role in the multidisciplinary management of mTBI. Currently, physicians are required to make diagnosis and clearance decisions for injured athletes before they can return to training, and eventually competition. Physicians have stated they lack the time to provide detailed and individualised therapy directly to the SOBI patient. There is potential to expand the role of physiotherapists in the management of SOBI.

Emerging evidence indicates that early identification of vestibulo-ocular abnormalities following SOBI is predictive of complicated clinical recovery >14 days [11]. SOBI patient’s presenting with vestibulo-ocular dysfunction may benefit from early referral to a specialised physiotherapist who can initiate an individualised treatment plan. Patients may develop vestibulo-ocular compensations if treatment is not promptly initiated.

Assessment of cervical spine/whiplash and disorders comorbid with SOBI may also be conducted by physiotherapists resulting in earlier recognition and initiation of treatment. The increased use of physiotherapists trained specifically in SOBI related assessment and rehabilitation may reduce the proportion of patients who experience complicated outcomes.

We call upon physiotherapists and sports physicians to discuss how in New Zealand we can improve early identification of the predominant symptom cluster and develop therapy protocols that can be individualised for SOBI patients.

References

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10. Ellis, M.J., et al., Vestibulo-ocular dysfunction in pediatric sports-related concussion. Journal of Neurosurgery: Pediatrics, 2015. 16(3): p. 248-255.

11. Ellis, M.J., et al., Multidisciplinary management of pediatric sports-related concussion. The Canadian Journal of Neurological Sciences, 2017. 44(1): p. 24-34.

12. Leddy, J., et al. A randomized controlled trial of assessment of exercise tolerance in adolescents with acute Sport-Related Concussion (SRC). Clinical Journal of Sport Medicine., 2015. 25, 216 DOI: 10.1097/JSM.0000000000000199.

Josh McGeown HBK, MscKine, PhD Student Josh McGeown is a PhD student at Auckland University of Technology’s Sport Performance Research Institute New Zealand (SPRINZ). Josh’s research focuses on optimizing rehabilitation and return to play strategies for athletes injured during training and competition. For his PhD project, Josh will be working with athletes who have suffered a concussion during sport, and will evaluate the effectiveness of exercise based rehabilitation techniques on a wide variety of subjective and objective outcome measures of symptom recovery. The findings of Josh’s PhD will aid in improving postconcussion rehabilitation guidelines, and provide a better understanding of safe return to play practices.

Patria Hume is Professor of Human Performance at Auckland University of Technology’s Sport Performance Research Institute New Zealand (SPRINZ). She has an international reputation in sports biomechanics, kinanthropometry and sports injury prevention. Her work has been recognised with national and international awards, including the most prestigious award in her field –the International Society of Biomechanics in Sports Geoffrey Dyson Award 2016. She was the 2016 AUT University Medalist for her outstanding contribution to research and sustained and exceptional academic achievement. With over 600 scholarly publications her work has been cited over 5000 times.

Natalie Hardakerhas 15 years of mixed clinical and research experience in the area of Sports Injury Prevention and Rehabilitation. She currently has a role at ACC as a Senior Injury Prevention Specialist and is a PhD Candidate at AUT, Auckland, New Zealand. Her research area is the effect of the female sex hormones on the risk for and recovery from Sports Related Concussion. Natalie leads the Sports Collaboration Group (cross code group to address injury issues and management in sport) and has been actively involved in the development of the ACC National Guideline for Concussion in Sport.