Postconcussive Syndrome Following Sports-Related Concussion
Abstract and Introduction
Postconcussive syndrome is an increasingly recognized outcome of sports-related concussion (SRC), characterized by a constellation of poorly defined symptoms. Treatment of PCS is significantly different from that of SRC alone. Primary care physicians often are the first to evaluate these patients, but some are unfamiliar with the available therapeutic approaches. This review provides an overview of the pathophysiology of SRC and descriptions of both pharmacologic and nonpharmacologic treatment options to allow primary care physicians to provide evidence-based care to patients experiencing postconcussive syndrome.
Postconcussive syndrome (PCS) is defined as a constellation of symptoms occurring after a traumatic brain injury (TBI) and persisting for longer than 3 months, although the exact time frame is debatable. Diagnostic criteria are poorly defined but include the presence of at least three of the following symptoms: headache, dizziness, fatigue, irritability, insomnia, concentration or memory difficulty, and intolerance of stress or emotion. Each year, an estimated 10 million cases of TBI arise globally, 1.7 million occurring in the United States. Sports-related concussion (SRC) accounts for approximately 30% of minor TBI, the majority of which resolve spontaneously within 7 to 10 days; however, up to 33% of individuals may experience symptoms for more than 3 months following the initial injury. Patients with PCS have been referred to as "the walking wounded" because many of them struggle with lasting neuropsychiatric sequela that last weeks, months, or even years. An increasing amount of evidence suggests that concussion, although primarily a brain injury, involves more than just a disturbance of cerebral function and can actually affect multiple physiological systems. As a result, the treatment options for PCS range broadly from rehabilitative and alternative to psychopharmacologic measures.
Although the overall incidence of TBI is difficult to determine, the Centers for Disease Control and Prevention (CDC) estimates that 1.7 million Americans experience TBI annually. Sports and recreation account for a significant portion (30%) of minor TBI, and military blast injuries account for some of the most severe injuries. Comparing treatment of sports- and military-related TBI can be tempting, but should be approached with caution. Although approximately 92.3% of sports-related TBI are mild and 80% to 90% of military TBI may be mild, the impact of confounding variables unique to the military theatre on downstream sequela should not be underestimated. The sports-related incidence of TBI was estimated to be 45.6/100,000 in 2011, an increase from 19.7/100,000 in 1998, with the highest incidence rate occurring in adolescents 12 to 18 years old. This increased incidence in adolescents may be explained by physiologic differences between adult and developing brains, increasing the susceptibility to injury and time to recovery. The most common mechanisms were football (38%) and fall injuries in sports (20.3%), which include a variety of activities such as soccer, basketball, skating activities, cheerleading, and gymnastics. The most severe injuries were noted in off-road vehicular sports, repeated head trauma, and equestrian sport.