The prevention, detection, and related treatment of concussions is emerging as a new field of specialty, located somewhere between sports medicine and neurology. With concussions getting more and more air time in the media, a burgeoning industry has arrived, featuring the latest in technological advances.
While the industry has come a long way, it still has a way to go. However, new tools combining science with technology are putting this sub-specialty at the forefront of neurology and critical care, where early detection of acute brain injury could mean the difference between life and death.
The new era of concussion detection tools fall into three categories:
- Impact sensors
- Sideline assessments
Impact sensors are accelerometer devices that record forces transmitted to the head during collision. The latest in impact sensor technologies are now being attached to the helmet, within mouthguards, and directly to the skin.
They can detect linear and rotational forces applied to the head. Linear forces are measured in gravitational (or “G”) force, while rotational energy is measured in radians per second. Most sensors will record and report not only force of impact in real time but also track the number and severity of hits over time.
Although much research still needs to be done, impact sensor technology has already found a place on the sidelines to help detect acute concussion injury and the effects of successive sub-concussive hits. For example, the Sports Legacy Institute has initiated the Hit Count™ program in efforts to standardize the reporting and tracking of sub-concussive hits using helmet impact sensors such as Gforcetracker.com.
A new technology group out of Washington, i1 Biometrics, has developed sensors that track force and direction of impact events, helping spot concussion symptoms in the early stages with wearable mouthguard technology. Using wireless communications, the mouthguard device collects data and automatically alerts coaches on the sidelines if the severity of a hit reaches a certain threshold.
Other products are surfacing as well to track impacts, including patches that can be worn behind the ear or adhered to other surfaces. These wearable impact sensors also communicate via mobile technology to signal when a hit surpasses an established threshold. Examples include the Linx Impact Assessment System by BlackBox Biometrics Inc., and X2 Biosystems’ xPatch.
By counting and measuring the velocity of hits sustained to the head, we gain valuable data that can lead to prevention of concussions and further brain damage. However, further research is necessary to identify the appropriate threshold level of force,whether it’s 50G, 80G, or 100G, all the while considering the athlete’s age.
Integrating the data collected from impact sensors into a reporting software will greatly aid the medical professional in tracking hits and concussions, perhaps over the athlete’s career.
A number of sideline assessments are available and being developed to assist with detection during practice or gameplay, guiding the decision to allow the athlete to return or not.
The most significant prototype of sideline assessment tool for the acute assessment of concussion in sport is the SCAT3, which is designed specifically for use by medical professionals. It includes a Glasgow Coma Scale assessment, orientation, verbal memory, digit span, documentation of observed and reported symptoms, and the modified Balance Error Scoring System.
However, a few mobile apps have integrated the SCAT3 or similar assessments into a semi-automated assessment tool which can be transmitted electronically to the appropriate medical professionals for review. These assessments are not meant to diagnose a concussion in the absence of a medical professional on the sidelines, but rather document the condition of the injured athlete for a medical professional to review when available.
Some advanced sideline assessment mobile apps help document the BESS test, such as the Concussion Assessment and Response app. Other apps utilize the accelerometer technology built in to smartphones to measure balance, like the XLNTbrain mobile app and Sway Balance.
Oculomotor testing is finding its way onto the sidelines as well to help identify risk of concussion by measuring what is one of the brain’s most sensitive systems to the effects of traumatic injury. The King-Devick Test evaluates visual tracking and saccadic eye movements. The test uses rapid number naming that involves reading a string of numbers on three test cards to measure for saccades, attention, concentration, speech, and language. Significantly slower times indicate presence of concussion risk.
An up and coming sideline assessment is the on-location evaluation of electroencephalogram. Brainscope is developing a five-channel field test measuring the EEG from frontal and temporal regions with discriminant analysis in attempts to identify acute injury on the sideline.
Researchers at Notre Dame developed a detection system that prevents results from being swayed by answers given by a player who wants to continue to participate. The diagnostic tool required participants to simply speak into a mobile device.
Previous studies have found that head injuries change speech characteristics, with negative effects on vowel production in particular. The researchers initially tested the app with 125 boxers participating in a collegiate competition.
Before any bouts started, the researchers recorded each boxer saying the numbers one through nine as a baseline. After boxing, the researchers recorded the athletes reciting the numbers again. By analyzing several acoustic features of the vowel sounds, including their pitch, the app was able to identify all nine boxers who were later diagnosed with concussion.
A developing capability, not yet in use in the field, is using screening for blood and saliva biomarkers on the sideline or during recovery. Biomarkers being explored for this purpose include the S100 protein, tau protein, and the ApoA1 protein.
Although markers may be more sensitive to detecting acute concussion injury, the specificity of the tests still needs to be established. Technical challenges of obtaining and analyzing samples within a reasonable time on the sidelines need to be addressed.
It may be that these tests will not be useful in determining whether an athlete returns to the game on that day, but rather managing return to play decisions during the recovery period.
The Challenge of Universal Detection
Concussion injury may affect different regions of the brain. Because of this, no single subsystem of brain function is universally affected by concussion injury. For some athletes, the main symptoms may be cognitive or emotional, and for others balance and equilibrium. Some may present with deregulated sleep, and others with a headache.
Because of the diverse presentation of concussion injury, we cannot rely on an assessment of any one subsystem in order to detect brain dysfunction related to concussion. Rather, a blended assessment that evaluates cognition and emotional status, balance and oculomotor function, and features a graded symptom checklist is important in effective and thorough concussion detection and management.
Harry Kerasidis, MD, is the founder of Chesapeake Neurology Associates in Prince Frederick, Maryland and serves as the Medical Director for the Center for Neuroscience, Sleep Disorders Center, and Stroke Center at Calvert Memorial Hospital. He is the founder and medical director for the sports concussion management platform XLNTbrain, LLC. His new book, “Concussionology: Redefining Sports Concussion Management” comes out in May 2015.
For more information
- Lee H et al. “Smartphone and tablet apps for concussion road warriors (team clinicians): a systematic review for practical users.” Br J Sports Med. 2014; doi: 10.1136/bjsports-2013-092930.
- Kutcher JS et al. “What evidence exists for new strategies or technologies in the diagnosis of sports concussion and assessment of recovery?” Br J Sports Med. 2013 Apr;47(5):299-303.