Prognostic Utility of Immediate Memory and Delayed Recall Assessments for Adolescent Concussion.

Objective: To evaluate the prognostic utility of 10-word immediate memory and delayed recall assessments at an initial post-concussion evaluation for predicting persisting post-concussion symptom (PPCS) development.

Design: Retrospective cohort study.

Participants: Adolescents (N = 160) seen for concussion at a sports medicine center between June 2018 and November 2019.

Independent Variables: We categorized participants based on their symptom recovery time, as PPCS (symptoms >28 days) and no PPCS (symptoms ≤28 days).

Main Outcomes: Patients completed 10-word immediate memory and delayed recall assessments at the time of their initial evaluation. We grouped patients based on timing of their initial visit: 1 to 7 days post-concussion versus 8 to 21 days post-concussion and calculated their symptom duration (time from injury until symptom resolution).

Results: For patients seen 1 to 7 days post-concussion (N = 69; 14.4 ± 2.4 years; 41% female), those who developed PPCS (N = 19, 28%) had significantly worse immediate memory (6.2 ± 1.8 vs 7.2 ± 1.7 words correct; P = 0.04; Cohen d = 0.55) and delayed recall (3.6 ± 1.8 vs 5.5 ± 2.2 words correct; P = 0.002; Cohen d = 0.87) performance compared with those who did not develop PPCS. For patients seen 8 to 21 days post-concussion (N = 91; 14.1 ± 2.6 years; 53% female), there were no significant differences between those who developed PPCS (N = 45, 49%) and did not on immediate memory (7.2 ± 1.7 vs 6.7 ± 2.1 words correct; P = 0.21; Cohen d = 0.26) or delayed recall (5.2 ± 2.3 vs 5.4 ± 2.1 words correct; P = 0.61; Cohen d = 0.11) performance.

Conclusions: The 10-word immediate memory and delayed recall assessments have prognostic utility for PPCS when administered within the first week post-concussion and may help clinicians identify those at greatest risk of developing PPCS.