A Study on the Effect of Mindfulness-based Yoga on Youth With Persistent Concussion Symptoms

Mild traumatic brain injury (mTBI), also known as concussion, is of great concern in the youth population, with incidences of injury steadily increasing within the past few years. Current Canadian estimates have indicated that the total rate of concussions per 100,000 increased from 467 to 754 for boys and from 209 to 441 for girls from 2003-2010. As defined by the recent Zurich Consensus statement, concussion is a pathophysiological injury induced by biomechanical forces, which can be caused by impact to the head, neck or body. In 10-20% of youth, concussion symptoms persist in the weeks, months or even years following the injury. Consequently, youth with persistent concussion symptoms are unable to fully participate in the meaningful activities (e.g. attending school, engaging with friends and community) they did prior to the injury and experience a reduced quality of life.

Persistent concussion symptoms in youth requires an approach that directly addresses the rumination and attention to distressful thoughts about their functional performance, while still promoting appropriate levels of physical and cognitive demands. Targeting these constructs may shift the focus away from symptoms, while building self-efficacy and enhancing participation in daily activities. Mindfulness-based yoga (MBY) is a mind-body intervention that uses physical yoga poses, purposeful breathing techniques and a focus on being in the present moment. MBY encourages participants to develop moment-to-moment awareness of physical sensations, emotions, and thoughts, and promotes the cultivation of non-judgemental and accepting relationships to personal experiences. In chronic pain, fibromyalgia, mental health and now TBI populations, MBY has demonstrated benefits in physical (i.e. increased muscle strength, endurance), psychological (i.e. decreased stress, increased self-efficacy), cognitive (i.e. increased concentration) and social (i.e. emotional regulation, improved mood) domains. Although mindfulness based yoga has been validated as a form of rehabilitation in the adult population, its applicability for youth with persistent concussion symptoms has yet to be explored. Understanding the impact of a MBY intervention on this population may enhance management of persistent symptoms and ultimately, participation in meaningful activities.

In addition to the functional sequelae that ensue following this injury, concussion in both the acute and persistent phases is being recognized as a neurophysiological injury. Traditional methods of assessment following concussion place emphasis on subjective self-report and administration of neuropsychological batteries. These assessments are used in an effort to return the youth to activity (i.e school, sport). However, these methods can be unreliable as youth have a high incentive to return to play and neurocognitive resolution does not necessarily equate to pre-injury function. To augment these measures, an objective indicator of neurophysiological stress is needed. Heart rate variability (HRV) is an objective, neurophysiological indicator of autonomic nervous system functioning. HRV is quantified by measuring the time intervals between heartbeats. Increased variability in heart rate (i.e. increased HRV) is seen as healthy neurophysiological function, demonstrating an individual's ability to adapt and be flexible to the demands of the environment. Conversely, decreased HRV is demonstrative of an individual's reduced ability to respond flexibly to their environment. Investigating the impact of persistent concussion symptoms on HRV has the potential to enhance our understanding of autonomic nervous system functioning in the chronic phases of this injury for an understudied population.

The specific objectives are to: (1) adapt the MBY intervention protocol to suit the unique needs of youth with mTBI (i.e. safety, fatigue), (2) collect data on the impact of MBY on HRV, self-efficacy and participation, (3) describe changes in HRV, self-efficacy and participation associated with MBY across pre-intervention, post-intervention and 3 months following intervention, (4) identify if post concussion symptoms change (i.e. increase or decrease) following MBY and (5) identify if changes in post concussion symptoms occur with changes in HRV, self-efficacy and participation.