Mild traumatic brain injury (mTBI) presents a substantial burden to patients, families, and health care systems. Whereas, recovery can be expected in the majority of patients, a subset continues to report persisting somatic, cognitive, emotional, and/or behavioral problems, generally referred to as post-concussion syndrome (PCS). However, this term has been the subject of debate since the mechanisms underlying post-concussion symptoms and the role of pre- and post-injury-related factors are still poorly understood. We review current evidence and controversies concerning the use of the terms post-concussion symptoms vs. syndrome, its diagnosis, etiology, prevalence, assessment, and treatment in both adults and children. Prevalence rates of post-concussion symptoms vary between 11 and 82%, depending on diagnostic criteria, population and timing of assessment. Post-concussion symptoms are dependent on complex interactions between somatic, psychological, and social factors. Progress in understanding has been hampered by inconsistent classification and variable assessment procedures. There are substantial limitations in research to date, resulting in gaps in our understanding, leading to uncertainty regarding epidemiology, etiology, prognosis, and treatment. Future directions including the identification of potential mechanisms, new imaging techniques, comprehensive, multidisciplinary assessment and treatment options are discussed. Treatment of post-concussion symptoms is highly variable, and primarily directed at symptom relief, rather than at modifying the underlying pathology. Longitudinal studies applying standardized assessment strategies, diagnoses, and evidence-based interventions are required in adult and pediatric mTBI populations to optimize recovery and reduce the substantial socio-economic burden of post-concussion symptoms.

Objective. To determine the prevalence of vision diagnoses after concussion in adolescents. Methods. Cross-sectional study from July 1, 2013 to February 28, 2014, of patients aged 11 to 17 years with concussion evaluated in a comprehensive concussion program. Results. A total of 100 adolescents were examined, with a mean age of 14.5 years. Overall, 69% had one or more of the following vision diagnoses: accommodative disorders (51%), convergence insufficiency (49%), and saccadic dysfunction (29%). In all, 46% of patients had more than one vision diagnosis. Conclusions. A high prevalence of vision diagnoses (accommodative, binocular convergence, and saccadic eye movement disorders) was found in this sample of adolescents with concussion, with some manifesting more than one vision diagnosis. These data indicate that a comprehensive visual examination may be helpful in the evaluation of a subset of adolescents with concussion. Academic accommodations for students with concussion returning to the classroom setting should account for these vision diagnoses.

Concussion in youth has received heightened attention owing to emerging evidence that this common injury can affect academics and cause behavioral changes and neurocognitive deficits in working memory, concentration, processing speed, and eye and motor function.^1-3 Reported estimates of the number of youth with concussion have increased in recent years, likely owing in part to increased involvement in youth sports, introduction of return-to-play legislation, and increased awareness of concussion by clinicians, parents, and youth themselves.^1,4-6

Objective: This review provides an in-depth overview of diagnostic schema and risk factors influencing recovery during the acute, subacute (operationally defined as up to 3 months postinjury), and chronic injury phases across the full spectrum of individuals (e.g., athletes to neurosurgery patients) with mild traumatic brain injury (mTBI). Particular emphasis is placed on the complex differential diagnoses for patients with prolonged postconcussive symptoms. Methods: Select literature review and synthesis. Results: In spite of an increase in public awareness surrounding the acute and potential long-term effects of mTBI, the medical field remains fragmented both in terms of the diagnostic (different criteria proffered by multiple medical organizations) and prognostic factors that influence patient care. Conclusions: Given the lack of objective biomarkers and the spectrum of different disorders that likely encompass mTBI, clinicians are encouraged to adopt a probabilistic, rather than definitive, diagnostic and prognostic framework. The relevance of accurately diagnosing and managing the different manifestations of mTBI becomes clear when one considers the overall incidence of the disorder (42 million people each year worldwide), and the different treatment implications for patients with a true neurodegenerative disorder (e.g., chronic traumatic encephalopathy; rare) vs potentially treatable conditions (e.g., depression or posttraumatic headache; frequent).