Elevated levels of neurofilament light proteins and decreased amyloid β in cerebrospinal fluid (CSF) may represent markers of central nervous system (CNS) injury among patients with postconcussive syndrome (PCS), according to a study published in JAMA Neurology. Although symptoms of mild TBI are typically short-lived, up to 15% of patients will develop PCS, or mTBI symptoms that persist beyond 3 months.
Researchers evaluated professional Swedish ice hockey players for CSF markers of CNS injury. Of 31 participants, 16 were hockey players with PCS due to repeated mTBI, and 15 were healthy controls with no PCS. Players who had PCS symptoms for more than 1 year had higher levels of neurofilament light protein, a marker of axonal white matter damage, compared with players whose PCS symptoms resolved within 1 year and normal controls (median, 410 pg/mL vs 210 pg/mL and 238 pg/mL, respectively; P = .04 and P = .02, respectively). Amyloid β levels were significantly lower in all players with PCS than in controls (median, 1000 pg/mL vs 1094 pg/mL; P = .05). “Increased neurofilament light proteins and reduced amyloid β were observed in patients with PCS, suggestive of axonal white matter injury and amyloid deposition,” the authors concluded.