Chronic Exertional Symptoms Post-Concussion in the Military: Roles of Heart Rate Variability, Exercise, and Text Message Monitoring

Chronic Exertional Symptoms Post-Concussion in the Military:

Roles of Heart Rate Variability, Exercise, and Text Message Monitoring

Created by: Sarah Morrison, SPT

Background

During my second year clinical rotation in the TBI clinic at Fort Bragg, I came into contact with many military service members (SM’s) with chronic concussion symptoms (headache, vertigo, etc.) that severely decreased their quality of life and limited their ability to perform their active duties and daily functional activities. Their symptoms were especially aggravated by the physical demands necessary to perform military jobs. A progressive exercise program based on maximum heart rate reached during the Buffalo Concussion Treadmill Test (BCTT) often led to improvement in symptoms and even the ability to return to full duty and exercise without significant limitations.

I became very interested in helping these individuals recover, and was interested to find that there is very little research and no real consensus on the effectiveness of graded exercise treatment or evaluation for military with chronic exertional symptoms post-mTBI. My advisor, Karen McCulloch, has a long history of working with military mTBI research and advocating for individuals with mTBI symptoms. So I was very excited to have the opportunity to work with her to appraise the available evidence on the topic and add updated information on treatment and patient monitoring by mobile phone to a proposal for funding of a randomized clinical trial.

Overview

Since 2001, over 325,000 SM’s have sustained a traumatic brain injury with over 80% of those being mTBI¹, and up to 35% of these mTBI’s result in chronic physical, sensory, emotional, and affective symptoms that make it unsafe for SM’s to perform full active duty responsibilities². Dysfunction of the autonomic nervous system (ANS) and reduced heart rate variability (HRV) have been shown to play a role in persistence of mTBI symptoms³, perhaps especially with exertional activities^4,5. The respiratory effects of exercise have been proposed to improve autoregulation and increase heart rate variability⁶. Preliminary research demonstrates a graded aerobic exercise program to be safe and effective for decreasing symptom number and severity, improving quality of life and lessening time necessary to return to activity in athletes^7,8.

However, current research is limited to only a few studies of low-level evidence with small samples and little randomization. No research specifically assesses the effectiveness of such a program in the military population or its ability to alter HRV. Available evidence suggests sub-symptom graded aerobic exercise to be safe and effective, but best clinical judgement and patient preferences should also be taken into account to make the most informed treatment decisions.

Potential barriers to further research and treatment include cost, time and manpower necessary for treatment and symptom monitoring, and unwillingness of military personnel to participate in formal treatment of mTBI. A mobile phone text message system of symptom monitoring may help overcome these barriers⁹, as well as improve severity and self-management of symptoms¹⁰. Again, research is limited in the military population, but available evidence indicates text messaging has good potential to be a feasible monitoring system in treatment and research.

Gathering Evidence

I began literature review in our fall semester Evidence Based Practice II course with the clinical question, “In a 30 year old active military male suffering from post-traumatic headaches (PTH) during physical exertion, is a progressive aerobic exercise program effective for decreasing headache pain with physical activity?”. Due to the lack of research specifically regarding headache, I expanded my critically appraised topic (CAT) to include post-concussion symptoms. I reran the search this semester to review the latest evidence and expanded my review to investigate the feasibility of using mobile phone technology to monitor SM’s chronic post-concussion symptoms and responses to treatment. Creating a CAT and performing the literature review revealed how little research has been done on either topic, especially in the military population, highlighting how this project could help achieve grant approval for necessary future research.

The Project

Kmac and I met in the fall to discuss possible involvement in performing literature review to add current evidence to a proposal for a randomized trial investigating the effect of graded exercise treatment on HRV and symptom management in military personnel with chronic exertional symptoms following mTBI. While we had hoped to also analyze pre-existing data on patients undergoing treatment at Fort Bragg Army Base, the available data was unfortunately insufficient.

Kmac continues to participate in multi-disciplinary collaboration on this topic and helped me better understand the slow and multi-faceted process of research and grant approval. While I was unable to perform data analysis, I did continue with the literature review and making additions to Kmac’s research proposal. The two papers I wrote discuss the current literature on the role of Heart Rate Variability and Exercise Treatment in military SM’s with chronic concussion symptoms exacerbated by exertion, as well as the feasibility of Text Message Monitoring in this population during clinical research and treatment.

I also intended to collect heart rate and symptom data from a potential case study participant with chronic concussion symptoms. However, after performing the Buffalo Concussion Treadmill Test (a submaximal graded exercise test) while tracking heart rate and rating of perceived exertion, it was apparent that his symptoms were not exertional in nature. However, I was able to try text messaging to monitor headache symptoms and provide support on a daily basis over the course of a couple of weeks prior to testing. His response rate was 100%, and he reported after testing that the text check-ins were not burdensome to his daily schedule. He also reported that the text support helped ease his worries about his symptoms and aided his self-management.

Evaluation

I sought feedback from Dr. Karen McCulloch through in-person meetings, phone conversations, and emails. My final project incorporates her evaluation and critique.

While my project did not result in a case study or direct patient data analysis, I hope my work will help strengthen future proposal submission and play a positive role in furthering research on this important topic. I hope to remain involved in deepening our knowledge on this subject through evaluating direct patient treatment and outcomes, as well as possibly continuing to work with Dr. McCulloch in future research.

Self-Assessment

This capstone project taught me so much about the many intricacies and potential unexpected roadblocks that play an important role in the research process. Reviewing and adding to Kmac’s original proposal and talking with her about the process of writing and submitting it made me realize the importance of flexibility, collaborative teamwork, persistence, and innovation in the research process. After realizing the difficulty in gaining grant approval and learning more about chronic concussion and the lack of evidence-based guidance that therapists have for treating so many affected SM’s, I feel even more strongly about remaining dedicated to the advancement of the research process for this topic.

I felt good about my high level of independence with the project and my ability to remain flexible in the face of obstacles to the project. Even with the challenges, I held myself accountable for creating the highest quality work possible and avoided frustration. These skills will come in handy later in my career, and being able to utilize them now gives me confidence to practice as an independent physical therapist in the future.

Acknowledgements

I would like to thank Karen McCulloch, PT, PhD, NSC for allowing me to take part in her grant proposal writing and for her feedback throughout this process. I would also like to thank Amy Cecchini, MS, PT for her efforts to collect data at Fort Bragg and her willingness to be a part of my committee. Lastly but most definitely not least, I would like to give a big thank you to my wonderful UNC DPT classmates (especially Miss Elizabeth Nixon, SPT) for supporting me throughout the capstone process, as well as throughout the entire three years of our DPT program.

 References

1. DoD worldwide numbers for TBI. Defense and Veterans Brain Injury Center Web site. http://dvbic.dcoe.mil/dod-worldwidenumbers-tbi. Published May 15, 2015. Accessed April 1, 2016.
2. Schneiderman AI, Braver ER, Kang HK. Understanding sequelae of injury mechanisms and mTBI incurred during the conflicts in Iraq and Afghanistan: persistent PCS and PTSD. Am J Epidemiol. 2008;167:1446-52
3. Keren O, Yupatov S, Radai MM, et al. Heart rate variability (HRV) of patients with traumatic brain injury (TBI) during the postinsult sub-acute period. Brain Inj. 2005;19:605–611.
4. Abaji JP, Curnier D, Moore RD, Ellemberg D. Persisting effects of concussion on heart rate variability during physical exertion. Journal of Neurotrauma. doi:10.1089/neu.2015.3989.
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6. Brown RP, Gerbarg PL. Sudarshan Kriya yogic breathing in the treatment of stress, anxiety, and depression: part I-neurophysiologic model. J Altern Complement Med. 2005;11:189–201.
7. Leddy JJ, Koslowski K, Donnelly JP, Pendergast DR, Epstein LH, Willer B. A preliminary study of subsymptom threshold exercise training for refractory post-concussion syndrome. Clinical Journal of Sport Medicine. 2010;20(1):21-27.
8. Schneider KJ, Iverson GL, Emery CA, McCrory P, Herring SA, Meeuwisse WH. The effects of rest and treatment following sport-related concussion: a systematic review of the literature. The British Journal of Sports Medicine. 2013;47:304-307.
9. Zinzow HM, et al. Connecting active duty and returning veterans to mental health treatment: interventions and treatment adaptations that may reduce barriers to care. Clin Psychol Rev. 2012;32(8):741-753.
10. Suffoletto B, Wagner A, Arenth PM, et al. Mobile phone text messaging to assess symptoms after mild traumatic brain injury and provide self-care support: a pilot study. Journal of Head Trauma Rehabilitation. 2013;28(4):302-312.