Continuous EEG detection of DCI and seizures following aSAH: a systematic review

Objective: Delayed cerebral ischemia (DCI) and seizures are dreaded neurological complications following aneurysmal subarachnoid hemorrhage (SAH). They may lead to severe mortality or mobility. Continuous electroencephalography (cEEG) is quite useful for secondary brain injury monitoring. This study aims to assess the effectiveness and sensitivity of cEEG in detecting DCI and seizures.Methods: Reports published up to July 31, 2018 were retrieved from PubMed, Medline, Cochrane and EMABSE. A systematic review was carried out on eligible studies.Results: 1. DCI was diagnosed in 20%-62% of aSAH patients, which was detected by a decrease on alpha/delta ratio; DCI can be predictive from 7 h to 1.9 days prior to standard diagnosis by CT, TCD and MRI. 2. Nonconvulsive status epilepticus (NCSE) occurred in 2.9%-30.8% of aSAH patients, and nonconvulsive seizures (NCSZ) in 6-23%; poor outcomes (high disability and mortality) were associated with NCSE.Conclusions: cEEG is an effective monitoring tool for early detection of DCI and seizures, which may help to improve the diagnostic accuracy and provide early treatment for patients with aSAH.