Acute And Sub-acute Differences In Neurophysiology And Cognition Post-concussion

There are conflicting findings about the acute effects of concussion on neurophysiology and cognition. It is also unclear whether those effects last in the sub-acute stage and whether there are differences in these concussion outcomes between males and females. PURPOSE: To determine the acute and sub-acute effects of concussion in males and females on neurophysiological and cognitive outcomes compared to healthy controls. METHODS: Eight individuals who were acutely concussed (81.8 ± 13.8 hrs post-injury, 20.9 ± 2.0 years; 4 F) and 8 healthy individuals who were age- and sex-matched (21.6 ± 2.7 years; 4 F) participated in this study. The concussion group attended the lab within 4 days and again at 14 days post-injury. Control participants followed a similar testing timeline. Outcome measures included i) symptoms – SCAT6 symptom questionnaire, ii) neurophysiology – corticospinal excitability and inhibition via transcranial magnetic stimulation, and iii) cognition – 12-item online cognitive battery. RESULTS: The concussion group reported a significantly greater number and severity of symptoms at both time points compared to the control group (p < 0.001); however, there were no significant sex-related differences (p ≥ 0.57). There were no significant differences between groups in neurophysiology (p ≥ 0.20) and cognitive (p ≥ 0.24) outcomes. However, females had greater corticospinal excitability compared to males (p = 0.007). Overall, females performed worse (p = 0.03) in the response inhibition cognitive domain compared to males. There was a sex*time interaction in the verbal reasoning domain (p = 0.02), where females showed no significant difference across time, while males demonstrated an improvement from the first visit to the second (p = 0.02). CONCLUSION: In these preliminary findings, males and females demonstrated a similar number and severity of symptoms. Although neurophysiology and cognitive outcomes showed no significant group differences, females showed greater corticospinal excitability but worse performance in some cognitive domains.