- Serum level of neurofilament light (NfL) performs well as a diagnostic and prognostic indicator in patients with traumatic brain injury (TBI).
Why this matters
- Editorial commends studies but says hurdles remain, including standardizing measurements and establishing cutoffs by age group and TBI severity.
- Prospective dual-cohort study.
- Swedish cohort:
- 45 hockey players with acute concussion.
- 31 with repetitive concussion having persistent symptoms.
- 28 preseason controls.
- 14 nonathletic controls.
- US clinic-based cohort:
- 162 patients with subacute or chronic TBI.
- 68 healthy controls.
- Main outcome: discrimination of TBI presence, severity, prognosis.
- Funding: Intramural Research Program at NIH; Department of Defense.
- Among hockey players:
- Both cerebrospinal fluid (CSF) and serum NfL distinguished players with postconcussive symptoms lasting >1 year vs ≤1 year (areas under curve [AUCs], 0.80 and 0.81).
- Serum NfL distinguished players with postconcussive symptoms lasting >1 year vs preseason controls (AUC, 0.97).
- Among clinic patients:
- Baseline serum NfL distinguished patients with mild TBI vs moderate TBI (P<.001 severe tbi>=.048).
- Serum NfL in TBI group decreased over 5 years (P.0001), but was still higher than for controls.
- Serum NfL correlated with Glasgow Outcome Scale-Extended functional outcome (P=.0002).
- Related study suggests serum NfL outperforms serum glial fibrillary acidic protein, tau, ubiquitin C-terminal hydrolase-L1.
- Lack of CSF samples in some players.
- Number of concussions in preseason athletes is unknown.
- Unavailable longitudinal data for some points.