By David M. Schwartz, Ph.D., ABPdN
The topic of concussion has become very popular in recent years. As a result, research has improved our knowledge about concussion and public awareness has increased substantially. Unfortunately, there has also been a significant increase in misinformation related to concussion.
The 5th International Conference on Concussion in Sport was held in Berlin in October 2016, and a Consensus Statement on Concussion in Sport was prepared. The Workgroup producing this Consensus Statement included some of the most prominent neurologists, neuropsychologists and sports medicine physicians working in concussion.
In February 2017, the 2017 Berlin Concussion in Sport Group (CISG) published this Consensus Statement, and it was quickly adopted as the Berlin Guidelines for Concussion1 by most of the professional organizations and specialties that care for individuals with concussion. These guidelines were expanded to apply to concussions that occur outside of sports. This was important because it provides a uniform understanding and approach to the assessment and management of concussion.
The Berlin Guidelines define a concussion as follows:
Sport related concussion (SRC) is a traumatic brain injury induced by biomechanical forces. Several common features that may be utilized in clinically defining the nature of a concussive head injury include:
• SRC may be caused either by a direct blow to the head, face, neck or elsewhere on the body with an impulsive force transmitted to the head.
• SRC typically results in the rapid onset of short-lived impairment of neurological function that resolves spontaneously. However, in some cases, signs and symptoms evolve over a number of minutes to hours. SRC may result in neuropathological changes, but the acute clinical signs and symptoms largely reflect a functional disturbance rather than a structural injury and, as such, no abnormality is seen on standard structural neuroimaging studies.
• SRC results in a range of clinical signs and symptoms that may or may not involve loss of consciousness. Resolution of the clinical and cognitive features typically follows a sequential course. However, in some cases symptoms may be prolonged.
• The clinical signs and symptoms cannot be explained by drug, alcohol or medication use, other injuries (such as cervical injuries, peripheral vestibular dysfunction, etc.) or other comorbidities (e.g., psycho- logical factors or coexisting medical conditions).
In addition, the 2017 CISG stated the following regarding some of the products on the market today described as concussion protection devices:
Although current helmet-based measurement devices may provide useful information for collision sports, these systems do not yet provide data for other (non-collision) sports, limiting the value of this approach. Furthermore, accelerations detected by a sensor or video-based systems do not necessarily reflect the impact to the brain itself, and values identified vary considerably between studies. The use of helmet-based or other sensor systems to clinically diagnose or assess Sport Related Concussion (SRC) cannot be supported at this time.
The Berlin Guidelines provide the most current research and clinical information available to diagnose and treat concussion. They include specific information on Sideline Evaluation including symptoms and signs, removal of a player from play, reevaluation of the patient, neuropsychological assessment, rest, rehabilitation, referral, recovery, reconsideration of different approaches for different populations, residual effects and sequelae, and risk reduction. As a result of this consensus statement, the approach to the identification and management of concussions has changed.
We now approach concussions with the understanding that they are a result of chemical and metabolic events within the brain, and the majority of patients recover completely. For example, Iverson, et al.2 have shown that recovery from SRC is usually complete within 4 to 6 weeks for the majority of individuals experiencing concussion. Most uncomplicated concussions resolve in 10 to 14 days. Consequently, most of the uncomplicated concussion recovery approaches do not require medication to facilitate recovery or minimize symptoms. This is not as true for more complicated concussions that involve multiple types of symptoms.
When a concussion is suspected, an evaluation by a healthcare professional trained in concussion is recommended. The Berlin Guidelines state the following:
It is recommended that all athletes should have a clinical neurological assessment (including evaluation of mental status/cognition, oculomotor function, gross sensorimotor, co- ordination, gait, vestibular function and balance) as part of their overall management. This will normally be performed by the treating physician, often in conjunction with computerized NP screening tools.
At the Concussion Institute (CI) at Gwinnett Medical Center – Duluth, we follow the Berlin Guidelines closely for all of our patients. Initial evaluation includes all of the components outlined by the Berlin Guidelines. Patients are often initially evaluated by our neurologists and neuropsychologists. A brief history is taken, and a diagnostic interview obtains information about the type of injury, the mechanism of injury and the sequelae of the injury. Patients complete computerized assessments and undergo evaluation of sensorimotor, vestibular functions and balance.
Computerized assessment is completed through the use of the Immediate Post Concussion and Cognitive Testing tool known as ImPACT. This is the same tool that is utilized by teams in the NFL, NHL, NCAA and high school sports.
ImPACT is a computer-administered assessment of neurocognitive functions. It measures basic verbal memory, visual memory, visuomotor (hand-eye) coordination, impulse control and cognitive efficiency. It is not as comprehensive as a neuropsychological evaluation, but it does provide significant amounts of data to assist in the diagnosis of concussion.
It is important to remember that no one measure should be used to diagnose concussion, and ImPACT was not designed to be a stand-alone diagnostic measure for concussion. However, one of the most important contributions of the ImPACT measure is that it can be used as a recovery progress monitor. This assists the physician in identifying recovery and those areas that are lagging behind.
Another computerized measure used is the RightEye assessment. RightEye uses an eye tracker to precisely measure oculomotor functions. Functions measured by the assessment include circular smooth pursuits, horizontal and vertical smooth pursuits, horizontal and vertical saccades, fixation stability, choice reaction time and discriminate reaction time. These are areas that may be affected by concussion and the related sequelae. As with ImPACT, the ability to use this tool as a recovery progress monitor makes it a valuable part of the assessment and management of concussion.
In addition to computerized assessments, there are several areas that are clinically evaluated. These include balance, vestibular function, sensorimotor functioning, gait, active range of motion and response to physical exertion. The results of these assessments are combined with the results of ImPACT and RightEye to facilitate the diagnosis of concussion. In addition, the combination of tools contribute to making appropriate referrals for more comprehensive neurological, vestibular and sleep medicine evaluations. Patients benefit greatly from this comprehensive approach to concussion diagnosis and management.
Finally, research by Collins, et al. (2013)3 and Henry, et al. (2015)4 have identified six recovery trajectories that impact and potentially prolong recovery from a concussion. These recovery trajectories and the research done to identify them are unique, can occur in combination, and respond to specific and differentiated types of treatment and management.
The trajectories identified by the research are Cervical, Oculomotor, Vestibular, Cognitive/Fatigue, Anxiety/Mood and Post-Traumatic Headache/Migraine. Two other trajectories that have been identified through clinical practice are Sleep Dysfunction and Pre-Injury and Comorbid Medical Factors. Identification of the recovery trajectory and using the designated evidence-based approaches results in resolution of the concussion and shortening of the time to recover fully.
References:
1. McCrory P, Meeuwisse W, Dvorak J, et al. Consensus statement on concussion in sport—the 5th international conference on concussion in sport held in Berlin, October 2016. Br J Sports Med Published Online First April 26, 2017. doi:10.1136/bjsports-2017-097699.
2. Iverson GL, Brooks B, Collins MW, Lovell MR. Tracking neuropsychological recovery following concussion in sports. Brain Injury, 2006: 20(3), 245-252.
3. Collins, M.W., Kontos, A.P., Reynolds, E., Murawski, C.D., Fu, F.H. A comprehensive, targeted approach to the clinical care of athletes following sport-related concussion, Knee Surg Sports Traumatol Arthrosc, DOI 10.1007/s00167-013- 2791-6.
4. Henry, L.C., Elbin, R.J., Collins, M.W., Marchetti, G., Kontos, A.P. Examining Recovery Trajectories After Sport-Related Concussion With a Multimodal Clinical Assessment Approach. Neurosurgery, Volume 78, Number 2, February, 2016.
