Brain Network Activation Technology Does Not Assist with Concussion Diagnosis and Return to Play in Football Athletes

Neurophysiological Markers to Guide Return to Sport After Sport-Related Concussion

SUMMARY

Sport-related concussion (SRC) has been defined as a subset of mild traumatic brain injury (mTBI), without structural abnormalities, reflecting a functional disturbance. Over the past decade, SRC has gained increasing awareness and attention, which coincides with an increase in incidence rates. Because this injury has been considered one of the most challenging encounters for clinicians, there is a need for objective biomarkers to aid in diagnosis (i.e., presence/severity) and management (i.e., return to sport) of SRC/mTBI.The primary aim of this article was to present state-of-the-art neurophysiologic methods (e.g., electroencephalography, magnetoencephalography, transcranial magnetic stimulation, and autonomic nervous system) that are appropriate to investigate the complex pathophysiological process of a concussion. A secondary aim was to explore the potential for evidence-based markers to be used in clinical practice for SRC management. The article concludes with a discussion of future directions for SRC research with specific focus on clinical neurophysiology.

The Current Status of Concussion Assessment Scales: A Critical Analysis Review

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Concussion is a complex pathophysiologic process that affects the brain; it is induced by biomechanical forces, with alteration in mental status with or without loss of consciousness.

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Concussion assessment tools may be broadly categorized into (1) screening tests such as the SAC (Standardized Assessment of Concussion), the BESS (Balance Error Scoring System), and the King-Devick (KD) test; (2) confirmatory tests including the SCAT (Sport Concussion Assessment Tool), the ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing), and the VOMS (Vestibular Oculomotor Screening); and (3) objective examinations such as brain network activation (BNA) analysis, imaging studies, and physiologic markers.

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The KD, child SCAT3 (cSCAT3), child ImPACT (cImPACT), and VOMS tests may be used to evaluate for concussion in the pediatric athlete.

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Future work with BNA, functional magnetic resonance imaging, diffusion tensor imaging, and serum biomarkers may provide more objective assessment of concussion, neurologic injury, and subsequent recovery.

Nonverbal Hand Movement Durations Indicate Post-Concussion Symptoms of Athletes

Methods of post-concussion diagnosis are still under debate with regard to sensitivity, objectivity, reliability, and costs. Spontaneous displays of nonverbal hand movement behavior during interaction are indicative of psychopathology and are relatively simple to record and analyze. Increased continuous (irregular) body-focused hand movement activity in particular indicates psychopathologies that overlap in symptomatology with those of sport-related concussions (SRCs). We therefore hypothesized that the duration of "irregular," "on body," and "act on each other" hand movements is increased in athletes with SRC who suffer from post-concussion symptoms. Three matched groups of 40 athletes were investigated: 14 symptomatic athletes with a concussion, 14 asymptomatic athletes with a concussion, and 12 non-concussed athletes. Using the Neuropsychological Gesture (NEUROGES)-Elan analysis system, four certified raters analyzed all nonverbal hand movements that were displayed during a videotaped standardized anamnesis about concussion history, incidence, course of action, and post-concussion symptoms. The duration of irregular Structure units among symptomatic athletes was significantly longer compared with asymptomatic athletes. Irregular, on body, and act on each other hand movement durations correlated with post-concussion symptoms. Whereas the duration of irregular units significantly predicted the post-concussion symptom score, working memory performances showed only marginal effects. Increased duration of irregular hand movement units indicates post-concussion symptoms in athletes with SRC. Because the recording of spontaneous displays of nonverbal hand movement behavior is relatively simple and cost efficient, we suggest using the neuropsychological analysis of hand movement behavior as a future diagnostic parameter of concussion management protocols.

Advanced biomarkers of pediatric mild traumatic brain injury: Progress and perils

There is growing public concern about neurodegenerative changes (e.g., Chronic Traumatic Encephalopathy) that may occur chronically following clinically apparent and clinically silent (i.e., sub-concussive blows) pediatric mild traumatic brain injury (pmTBI). However, there are currently no biomarkers that clinicians can use to objectively diagnose patients or predict those who may struggle to recover. Non-invasive neuroimaging, electrophysiological and neuromodulation biomarkers have promise for providing evidence of the so-called "invisible wounds" of pmTBI. Our systematic review, however, belies that notion, identifying a relative paucity of high-quality, clinically impactful, diagnostic or prognostic biomarker studies in the sub-acute injury phase (36 studies on unique samples in 28 years), with the majority focusing on adolescent pmTBI. Ultimately, well-powered longitudinal studies with appropriate control groups, as well as standardized and clearly-defined inclusion criteria (time post-injury, injury severity and past history) are needed to truly understand the complex pathophysiology that is hypothesized (i.e., still needs to be determined) to exist during the acute and sub-acute stages of pmTBI and may underlie post-concussive symptoms.