Post-concussion syndrome is the persistence of a constellation of physical, cognitive, emotional, and sleep symptoms beyond the usual recovery period after a concussion. The World Health Organization’s International Classification of Diseases, 10th revision (ICD-10), defines PCS2 as
a syndrome that occurs following head trauma (usually sufficiently severe to result in loss of consciousness) and includes a number of disparate symptoms such as headache, dizziness, fatigue, irritability, difficulty in concentration and performing mental tasks, impairment of memory, insomnia, and reduced tolerance to stress, emotional excitement, or alcohol.
(WHO, 2010, F07.2)
The Diagnostic and Statistical Manual of Mental Disorders (DSM) no longer contains a specific entry for “postconcussional disorder.” Instead, the fifth edition of the DSM captures persistent concussive symptoms under “neurocognitive disorder due to traumatic brain injury” (APA, 2013, pp. 624ff). The diagnostic criteria specify that the neurocognitive disorder must persist “past the acute post-injury period.” There is concern that the symptoms associated with the diagnostic criteria for PCS are nonspecific and that they frequently occur in the absence of head injury and in conjunction with other psychiatric conditions (Ruff, 2011).
Several studies have looked at different approaches to predicting which athletes will be most likely to have a prolonged recovery (typically more than 2 weeks post injury). A study of high school and college athletes with concussions found that loss of consciousness, posttraumatic and retrograde amnesia, and greater symptom severity (an increase of 20 points or more on the Graded Symptom Checklist) within the first 24 hours following injury were associated with longer recoveries (7 or more days) (McCrea et al., 2013). The researchers also found that demographic variables, competition level (high school versus college), player position, mechanism of injury, concussion history, and acute scores on the Standardized Assessment of Concussion (SAC) and the Balance Error Scoring System (BESS) tests were not predictive of a longer recovery time (McCrea et al., 2013).
Chrisman and colleagues (2013) used High School RIO™ data to identify predictors of prolonged symptoms, defined as lasting 7 or more days, in high school athletes. Presenting with four or more symptoms
2The ICD-10 uses the term “postconcussional syndrome.”