The Effectiveness of Biofeedback for Individuals With Long-term Post-concussive Symptoms

Most concussions resolve within 7-10 days, but approximately 40% of individuals do not fully recover and suffer from persistent post-concussive symptoms. This 8-week intervention study will evaluate the efficacy of heart rate variability (HRV) biofeedback and neurofeedback on reducing the number and severity of concussion symptoms.

40% of minor head injuries are diagnosed with post-concussion syndrome 3 months after injury (Ingebrigtsen, Waterloo, Marup-Jensen, Attner, \& Romner, 1998). These individuals have persistent symptoms after completing conventional rehabilitation programs. Persistent post-concussion symptoms not only decrease quality of life (Ingebrigtsen et al, 1998), but also impair cognitive and motor performance and increase the likelihood of impaired driving performance (Preece, Horswill, \& Geffen, 2010) and motor vehicle accidents (Bivona et al, 2012). While case reports indicate that biofeedback can reduce the number and severity of post-concussive symptoms (Lagos, Thompson, \& Vaschillo, 2013; Thompson, Thompson, Reid-Chung, \& Thompson, 2013), no studies have systematically evaluated these biofeedback treatment programs.

HRV biofeedback works by displaying beat-to-beat heart rate data to the participant, and through operant conditioning with breathing techniques, the participant learns to control their HRV (Lehrer \& Gevirtz, 2014). This results in an increase in parasympathetic (PNS) activity and decrease in sympathetic (SNS) activity, which leads to reduced anxiety, and increased focus and concentration (Lagos, Bottiglieri, Vaschillo, \& Vaschillo, 2012). Neurofeedback works in a similar fashion, except it monitors brain wave power, frequency, and connectivity using quantitative electroencephalogram (EEG). Brain functioning is displayed while playing an electronic game, and the participant learns through operant conditioning to increase the amplitude of desired EEG frequencies, such as low beta waves that are associated with active problem solving, usually while simultaneously decreasing the amplitudes of undesired EEG frequencies (Conder \& Conder, 2014).

This will be an eight-week intervention where participants suffering from long-term post-concussion symptoms will be recruited using email from the cohort of individuals that have been discharged after completing a concussion rehabilitation protocol (BrainEx90) at Parkwood Institute in London, Ontario. Non-concussed control participants will be recruited using posters. Participants will complete pre, mid, and post-intervention driving simulation tasks, electrocardiogram and HRV measures, and subjective questionnaires. These will be utilized to evaluate the effectiveness of HRV biofeedback and neurofeedback in this difficult to treat population.

Eligibility Criteria:
Inclusion Criteria:

Participants in HRV and the HRV/Neurofeedback intervention arms, and the post-concussion control arm:

1. Previously suffered a clinically diagnosed concussion
2. Participated in, completed, and have been discharged from the BrainEx90 outpatient concussion rehabilitation program at Parkwood Institute
3. Continued post-concussive symptoms
4. 18 years of age or older
5. Access to transportation
6. Capable of utilizing hand-held technology (ie. cell phone, tablet, etc.)
7. Holds a valid Driver's License
8. English speaking

Participants in the non-concussed control arm:

1. 18 years of age or older
2. Holds a valid driver's license
3. English speaking
4. Has not suffered a concussion in the last two years

Exclusion Criteria:

All participants:

1. Any heart disease, pacemaker, abnormal heartbeat patterns, coronary artery disease, or bypass surgery
2. Any mental health disorder that would interfere with participation in the study
3. Under 18 years of age
4. Unable to provide written informed consent or complete questionnaires due to language or cognitive difficulties
5. Inability to operate a motor vehicle
6. Inability to look at a digital screen for 30 minutes

Participants in the non-concussed control arm:

1. Suffered a concussion in the last two years