Serum neurofilament light as biomarker of seizure-related neuronal injury in status epilepticus

Biomarkers of neuronal damage in status epilepticus (SE) would be of great relevance for clinical and research purposes. In a retrospective cross-sectional study, serum neurofilament light chain (NfL) levels were measured in patients with SE (30 subjects), patients with drug-resistant epilepsy (30 subjects), and healthy controls (30 subjects). Serum NfL levels were higher in patients with SE (median = 26.15 pg/ml) compared to both epilepsy patients (median = 7.35 pg/ml) and healthy controls (median = 6.81 pg/ml; p <.001). In patients with SE, serum NfL levels showed a high correlation with cerebrospinal fluid (CSF) NfL (τ =.68, p <.001) as well as with CSF total tau (t-tau) levels (τ =.627, p <.001); they were higher in SE lasting >24 h (p =.013), in refractory/superrefractory SE (p =.004), and in patients who died within 30 days or who presented a worsening of clinical conditions (p =.001). Values of >28.8 pg/ml predicted 30-day clinical worsening or death (odds ratio [OR] = 10.83, 95% confidence interval [CI] = 1.96–59.83, p =.006) and SE refractoriness (OR = 9.33, 95% CI = 1.51–57.65, p =.016). In conclusion, serum NfL levels are increased in SE and correlate with SE treatment response, duration, and outcomes, therefore representing a promising biomarker of seizure-related neuronal damage.