Seizures, CSF neurofilament light and tau in patients with subarachnoid haemorrhage

ObjectivesPatients with severe subarachnoid haemorrhage (SAH) often suffer from complications with delayed cerebral ischaemia (DCI) due to vasospasm that is difficult to identify by clinical examination. The purpose of this study was to monitor seizures and to measure cerebrospinal fluid (CSF) concentrations of neurofilament light (NFL) and tau, and to see whether they could be used for predicting preclinical DCI. MethodsWe prospectively studied 19 patients with aneurysmal SAH who underwent treatment with endovascular coiling. The patients were monitored with continuous EEG (cEEG) and received external ventricular drainage (EVD). CSF samples of neurofilament light (NLF) and total tau (T-tau) protein were collected at day 4 and day 10. Cox regression analysis was applied to evaluate whether seizures and protein biomarkers were associated with DCI and poor outcome. ResultsSeven patients developed DCI (37%), and 4 patients (21%) died within the first 2months. Six patients (32%) had clinical seizures, and electrographic seizures were noted in one additional patient (4.5%). Increased tau ratio (proportion tau10/tau4) was significantly associated with DCI and hazard ratio [HR=1.33, 95% confidence interval (CI) 1.055-1.680. P=.016]. ConclusionAcute symptomatic seizures are common in SAH, but their presence is not predictive of DCI. High values of the tau ratio in the CSF may be associated with development of DCI.