TBI: serum NfL gains more clout as diagnostic, prognostic tool

  • Shahim P & al.
  • Neurology
  • 8 Jul 2020

  • curated by Susan London
  • Clinical Essentials
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Takeaway

  • 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.

Study design

  • 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.

Key results

  • 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.

Limitations

  • Lack of CSF samples in some players.
  • Number of concussions in preseason athletes is unknown.
  • Unavailable longitudinal data for some points.