Monitoring concussion in a knocked-out boxer by CSF biomarker analysis.

Concussion is common in many sports, and the incidence is increasing. The medical consequences after a sport-related concussion have received increased attention in recent years since it is known that concussions cause axonal and glial damage, which disturbs the cerebral physiology and makes the brain more vulnerable for additional concussions. This study reports on a knocked-out amateur boxer in whom cerebrospinal fluid (CSF) neurofilament light (NFL) protein, reflecting axonal damage, was used to identify and monitor brain damage. CSF NFL was markedly increased during 36 weeks, suggesting that neuronal injury persists longer than expected after a concussion. CSF biomarker analysis may be valuable in the medical counselling of concussed athletes and in return-to-play considerations.