By Matthew E. Fink, MD, Editor
Professor and Chairman, Department of Neurology, Weill Cornell Medical College; Neurologist-in-Chief, New York Presbyterian Hospital
Dr. Fink reports he is a retained consultant for Procter & Gamble and Pfizer.
SOURCE: Moseby-Knappe M, Mattsson N, Nielsen N, et al. Serum neurofilament light chain for prognosis of outcome after cardiac arrest. JAMA Neurol 2018; Oct. 29. doi:10.1001/jamaneurology.2018.3223. [Epub ahead of print].
Determining the prognosis of neurological outcome after cardiac arrest is notoriously difficult. It usually is performed in a multimodal fashion and includes the clinical examination, electroencephalogram, somatosensory evoked potentials, brain imaging, and biochemical markers. The most commonly studied blood-based biomarkers after brain injury are S100 and neuron-specific enolase, but neither has shown high accuracy in predicting prognosis. Neurofilament light chain (NFL) is a new potential biomarker, for which elevated levels in the spinal fluid or blood indicate axonal injury in several neurological diseases.
Moseby-Knappe et al used an ultrasensitive assay to quantify serum and cerebrospinal fluid levels in patients who suffered cardiac arrest. They analyzed levels in 782 unconscious patients who had out-of-hospital cardiac arrest. Measurements were analyzed at 24, 48, and 72 hours after cardiac arrest. The main outcome measures were poor neurological outcome at six months of follow-up, defined by the Cerebral Performance Category Scale as category 3 (severe cerebral disability), category 4 (coma), or category 5 (brain death).
Of 782 eligible patients, 717 were included, with 80.9% men, and a median age of 65 years. At six months, 360 patients (50.2%) had poor neurological outcomes. Median serum NFL levels were significantly higher in patients with poor outcomes vs. good outcomes at 24 hours, 48 hours, and 72 hours. The NFL measurements showed a high overall performance and high sensitivities and specificities (69% sensitivity with 98% specificity at 24 hours). The serum NFL levels had greater performance than other biochemical serum markers (tau, neuron-specific enolase, and S100). At comparable specificities, serum NFL had greater sensitivity for poor outcomes compared to other diagnostic tests such as electroencephalogram, somatosensory evoked potential, head CT, and neurological examination. The authors concluded that measurement of serum NFL is highly predictive of long-term poor neurological outcome 24 hours after cardiac arrest and may be a helpful complement to other tests used to predict neurological prognosis.
