File
Sanzo P.1, McGeown J.2, Zerpa C.2, Lees S.3, Niccoli S.3
1Lakehead University, School of Kinesiology, Northern Ontario School of Medicine, Thunder Bay, Canada, 2Lakehead University, School of Kinesiology, Thunder Bay, Canada, 3Lakehead University, Northern Ontario School of Medicine, Thunder Bay, Canada
Background: Concussion continues to be a very common brain injury that is poorly understood and treated. Often times, variable symptoms persist for several months despite suggested rest. Typically, rest is prescribed in combination with education and reassurance. Although the majority of concussions improve within the first 7-10 days, many patients develop persistent symptoms and post-concussion syndrome (PCS). Extended rest beyond the initial few weeks often leads to increased physical, psychological, and social stress, deconditioning, and awareness of symptoms. The ability to track change using neurocognitive testing such as the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery or biological markers, including brain derived neurotrophic factor (BDNF), may assist with monitoring progress with treatment. The optimal treatment for persistent symptoms, however, is not well understood. Early evidence suggests the benefits of exercise on neuroplasticity and the ability of neurons to repair or create new synaptic connections in some neurologically impaired populations but the utility of exercise within the concussed population is not known.
Purpose: The purpose of this pilot study was to investigate the impact of a four week exercise program on cognitive function and salivary-BDNF levels in individuals diagnosed with PCS.
Methods: Nine participants (5 females; 4 males; age M = 16.33, SD ± 2.55; number of days with persistent symptoms of PCS M = 99.88, SD ± 79.95) were included. Subjects completed two assessments and 12 supervised exercise sessions over the course of four weeks. The pre- and post-treatment assessments included the collection of a saliva sample to measure BDNF concentrations followed by the completion of the Post-Concussion Symptom Scale (PCSS) and ImPACT battery to measure the degree of symptoms and neurocognitive function. The exercise sessions consisted of supervised, progressive aerobic and cardiovascular conditioning and balance retraining exercises. The intensity and difficulty of the exercises were progressed using pre-determined parameters and incremental increases. The data were analyzed using descriptive statistics and Paired Samples T-Tests with an alpha set at .05.
Results: Statistically significant improvement in the PCSS scores (t(8)=3.37, p=.01, d=0.56) and visual motor speed on ImPACT testing (t(8)=-2.56, p=.03, d=0.55) was found. There were no statistically significant changes in salivary-BDNF concentrations (t(8)=0.29, p=.78) and in verbal memory (t(8)=-1.68, p=.13), visual memory (t(8)= -1.73, p=.12), and reaction time (t(8)=-0.16, p=.88) on ImPACT testing.
Conclusion(s): A progressive exercise program resulted in decreased symptoms of PCS and improved visual motor speed but did not change other neurocognitive factors or salivary-BDNF levels.
Implications: The preliminary evidence is clinically relevant suggesting that exercise-based treatments may improve PCS outcome in a more favourable manner than simply prescribing prolonged rest. Further research is required exploring the effects of exercise on the different subgroups of the PCS population (physiologic, cervicogenic, vestibulo-occular) and how all groups respond to exercise.
Funding acknowledgements: Not applicable as work was unfunded.
Topic: Neurology
Ethics approval: Ethics approval was obtained from the Lakehead University Research Ethics Board
All authors, affiliations and abstracts have been published as submitted.
