According to Leddy et al. (2014), the 2012 Zurich Consensus Statement on Concussion in Sport defines a sport-related concussion as “a complex pathophysiological process affecting the brain, induced by biomechanical forces., which may becaused either by a direct blow to the head, face, neck, or elsewhere on the body with an “impulsive” force transmitted to the head.” There is no gold standard method for diagnosing a concussion so a clinical diagnosis is made based off a combination of widespread cognitive, emotional, and physical disturbances post injury. While the majority of patients recover within 2 to 4 weeks following a concussion, approximately 30% suffer from persistent post concussive symptoms (PPCS)(Leddy et al., 2018). Athletes can present asymptomatic at rest but can elicit reemerging symptoms during tasks that require physical and mental exertion as micro structural and functional abnormalities persist even after symptoms subside (Porter, Silverberg, &Virji-Babul, 2018). Tasks requiring both cognitive and physical exertion, such as return to sport participation, are often most problematic for concussed patients.
Because exercise intolerance is commonplace among the physical symptoms post concussion, recommendations for concussed patients have traditionally been to stop exercise secondary to symptom exacerbation, but evidence supports that strict rest beyond two days duration can prolong recovery. Leddy and colleagues(2018) found that moderate levels of physical activity during the first week following concussion reduced the incidence of PPCS in children and adolescents in comparison to those who did not participate in structured physical activity.In animal models, voluntary exercise following traumatic brain injury has also been shown to promote neuroplasticity, reduce neuronal degeneration and cell death, increase neuronal stem cell proliferation, and improve cognitive performance, whereas complete rest impedes symptom recovery (Leddy et al.,2018).
Prolonged rest coupled with social isolation worsen symptoms of concussion and delay recovery in adolescent athletes. Because the physically trained brain responds differently than the sedentary brain, exercise training can help improve cerebral blood flow and autonomic nervous system functioning, which are often disrupted post concussion due to altered sensitivity to carbon dioxide in the brain stem. Because adolescent athletes who performed high levels of activity reported worsened symptoms than those who performed moderate levels of activity post concussion, recent evidence emphasizes that tactfulness in prescribing a therapeutic dose of exercise for a progressive training program is needed to determine an adequate threshold of activity to safely facilitate recovery and return to sport without exacerbating symptoms (Leddy et al.,2018).
Cognitive symptoms, on the other hand, while often attributed to injury to the brain, are not exclusive to head injury alone as post concussive symptoms are commonplace in both PPCS and cervicogenic/vestibular disorders since symptoms of neck injury can closely mimic those of head injury in athletes. Leddy et al.(2014) suggests that concussion symptoms can emanate from the cervical spine as headache, dizziness, blurred vision, vertigo, poor concentration, and memory deficits can result from the acceleration and deceleration forces transmitted through the cervical spine in whiplash related injuries. When comparing the results of cognitive symptoms (difficulty concentrating, difficulty remembering, feelings lowed down, feeling mentally foggy, etc.) on the 22-symptom Post-Concussion Symptom Scale (PCSS) questionnaire, a validated instrument for assessing concussion symptoms, there was no significant differences in symptom scores between patients with PPCS and those with cervicogenic/vestibular disorders,suggesting that the source of post concussion symptoms can be multifactorial in nature. Consequently, clinicians should perform careful physical examinations of the cervical spine as well as screening of the vestibular/ocular systems to help identify sources other than the brain underlying post concussion symptoms and guide treatment interventions appropriately.
Mucha et al. (2014) found the vestibular/ocular motor screen (VOMS) to be highly sensitive and accurate in identifying athletes who experienced as port-related concussion. The VOMS consists of five domains including smooth pursuits, horizontal and verticalsaccades, near point of convergence distance, horizontal vestibular ocularreflex, and visual motion sensitivity. Concussed and non concussed athletes were administered the VOMS and PCSS and had to rate changes in headache, dizziness,nausea, and fogginess symptoms compared with their pretest baseline after each VOMS assessment to determine if each component provoked symptoms. The researchers found VOMS items to be positively correlated to total PCSS symptom scores. The VOMS was able to distinguish concussed from non concussed athletes as patients post concussion scored significantly higher on all of the VOMS components in comparison to controls that reported very few, if any, symptoms after each VOMS assessment.
In a study performed by Schneider et al. (2014), the number of days from the start of treatment until medical clearance to return to sport by a physician,determined by improvement in dizziness, headache, and neck pain, was measured in patients following concussion. All patients performed gentle range of motion exercises, stretching, and postural education whereas the intervention group received joint mobilization to the cervical and thoracic spine, cervical neuromotor retraining exercises targeting the craniovertebral flexors and extensors, and vestibular rehabilitation including adaptation and habituation exercises, gaze stabilization, canalith repositioning maneuvers, and static and dynamic balance exercises. A significantly higher proportion of patients who received cervical and vestibular interventions experienced significant symptom improvement as 73% were medically cleared to return to sport within 8 weeks of treatment compared to only 7% of controls. When screening indicates involvement of the cervical spine post concussion, cervical, vestibular, and visual interventions should be utilized to effectively manage symptoms.
Kristen Gasnick, SPT
Dr.Brandon Cruz PT,DPT
Board Certified in Orthopedics
Board Certified in Sports
Fellow in Training
Certified Strength & Conditioning Specialist
Leddy, JJ, Baker, JG, Merchant, A, Picano, J, Gaile, D, Matuszak, J, &Willer, B. (2014). Brain or Strain? Symptoms Alone Do Not Distinguish Physiologic Concussion From Cervical/Vestibular Injury. Clinical Journal of Sports Medicine;25(3):237-242.
Leddy, JJ, Haider, MD, Ellis, M, & Willer, BS. (2018). Exercise is Medicine for Concussion. Current Sports Medicine Reports;17(8):262-270.
Mucha, A, Collins, MW, Elbin, RJ, Furman, JM, Troutman-Enseki, C, DeWolf, RM,Marchetti, G, & Kontos, AP. (2014). A brief vestibular/ocular motorscreening (VOMS) assessment to evaluate concussions: Preliminary findings.American Journal of Sports Medicine;42(10):2479-2486.
Porter, S, Silverberg, ND, Virji-Babul, N. (2018). Cortical activity and network organization underlying physical and cognitive exertion in active young adult athletes: Implications for concussion. Journal of Science and Medicine inSport;2018:1-6.
Schneider, KJ, Meeuwisse, MH, Nettel-Aguirre, A, Barlow, K, Boyd, L, Kang, J,& Emery, CA. (2014). Cervicovestibular rehabilitation in sport-related concussion: a randomised controlled trial. British Journal of Sports Medicine;48:1294–1298.