Sleep Architecture Immediately After a Sport-Related Concussion Sustained During a Professional Rugby Union Match: A Retrospective Case Study.

PURPOSE: A sport-related concussion (SRC) can cause sleep disturbances within 72 hours of injury. However, most research focuses on sleep after >72 hours, with limited attention to acute sleep responses, despite their potential impact on SRC recovery.

METHODS

This case study examines a 22-year-old professional rugby union player who sustained an SRC during an away match. Sleep architecture (sleep stages: N1, N2, N3, and rapid eye movement [REM] sleep) and physiological responses during sleep over 4 nights were analyzed-sleep before injury (PRE), the 2 nights immediately following injury (INJ and INJ + 1), and after recovery from injury (POST)-using home-based polysomnography. Return transmeridian travel was undertaken on INJ + 1.

RESULTS

The player took 15 minutes to fall asleep and slept <6 hours on INJ, with reductions in N3 (19% vs 22%-37%) and REM sleep (18% vs 20%-32%) compared with all other nights. Despite increased N3 and REM sleep on INJ + 1, sleep disturbances persisted (23 min to fall asleep, 69 min of wake after sleep onset, 40 awakenings, and sleep efficiency below 85%). Compared with sleep on PRE and POST, mean oxygen saturation and heart-rate variability were lower, mean heart rate was elevated, and respiratory events during sleep were greater on INJ and INJ + 1.

CONCLUSION

Acute responses after the SRC included sleep disturbances and elevated sympathetic activity (during sleep). The player had difficulty achieving deep, restorative sleep the first night following the SRC, aligning with the non-restorative-sleep complaints commonly reported by concussed athletes on the night(s) immediately following injury.