Predicting Recovery Patterns After Sport-Related Concussion

Abstract

Context: Clinicians sometimes treat concussed individuals who have amnesia, loss of consciousness (LOC), a concussion history, or certain symptom types more conservatively, but it is unclear whether recovery patterns differ in individuals with these characteristics.

Objective: To determine whether (1) amnesia, LOC, and concussion history influence the acute recovery of symptoms, cognition, and balance; and (2) cognition and balance are influenced by acute symptom type.

Design: Cohort study.

Setting: Seven sports at 26 colleges and 210 high schools.

Patients or other participants: A total of 8905 collegiate (n = 1392) and high school (n = 7513) athletes.

Main outcome measure(s): The Graded Symptom Checklist, Standardized Assessment of Concussion, and Balance Error Scoring System were administered to all athletes during the preseason. To allow us to track recovery patterns, athletes diagnosed with a concussion (n = 375) repeated these assessments immediately after the injury, 3 hours postinjury, 1 day postinjury, and at 2, 3, 5, 7, and 90 days after injury.

Results: Athletes who experienced amnesia had markedly greater deficits in and a slower recovery trajectory on measures of symptoms, cognition, and balance. Athletes with 2 or more prior concussions demonstrated poorer balance than those with no previous history. Otherwise, LOC and concussion history largely did not affect symptoms, cognition, or balance. Greater deficits in balance scores were observed in athletes with all symptom types. Regardless of these characteristics, most athletes recovered within 7 to 10 days.

Conclusions: Athletes who experienced amnesia had more symptoms and greater deficits in cognition and balance. Symptoms and cognitive or balance deficits were not consistently associated with LOC or concussion history. Acute symptoms had a strong influence on balance scores and, to a lesser extent, on cognition. However, we found no evidence to support more cautious return-to-play decisions for athletes with these characteristics, as group recovery occurred within normal timelines. Our study supports current clinical practice: recommending that athletes be withheld from activity until they are asymptomatic, followed by a graduated return-to-play progression.

Keywords: Balance Error Scoring System; Standardized Assessment of Concussion; return to play; traumatic brain injuries.

Figure 1.

Recovery patterns of the Graded Symptom Checklist based on, A, amnesia, B, loss of consciousness, and C, concussion history. Athletes who experienced amnesia for 30 minutes or longer had greater overall symptom scores (P < .05) than those who experienced no or 30 minutes or less of amnesia. The groups did not differ based on loss of consciousness or concussion history. Symptoms for all groups returned to baseline by day 7 postinjury. Values estimated from linear mixed model with x-axis in log (time in hours +1). Continued on next page.

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Figure 2.

Recovery patterns of Standardized Assessment of Concussion (SAC) scores based on, A, amnesia, B, loss of consciousness (LOC), and C, concussion history. The overall score and slope of the curve showed deficits in both amnesia groups (0–30 and ≥30 minutes) for up to 72 hours postinjury (P < .05). Athletes with LOC at time of injury tended to score worse on the SAC than those with no LOC, but this trend failed to reach significance (P = .08). No differences in SAC scores were observed based on concussion history. All groups returned to baseline within 72 hours postinjury. Values estimated from linear mixed model with x-axis in log (time in hours +1). Continued on next page.

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Figure 3.

Recovery patterns of Balance Error Scoring System (BESS) scores based on, A, amnesia, B, loss of consciousness (LOC), and C, concussion history. Those athletes with 30 minutes or longer of amnesia had worse BESS scores for the first 48 hours postinjury than the short-duration and no-amnesia groups. The same trend was seen based on concussion history: athletes with 2 or more previous concussions had worse overall BESS scores for up to 48 hours postinjury than athletes with 1 or 0 previous concussions. Athletes with LOC had better scores for the first 48 hours postinjury than athletes who did not sustain LOC. All athletes returned to baseline by 72 hours postinjury. Values estimated from linear mixed model with x-axis in log (time in hours +1). Continued on next page.

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