Short paper Awakening from post anoxic coma with burst suppression with identical bursts Patrick J. Coppler a, * , Amanda E. Kusztos b , Mark Andreae c , Brad W. Butcher c , Ankur Doshi a , Maria E. Baldwin d , Niravkumar Barot d , James F. Castellano a , Joanna S. Fong-Isariyawongse d , Alexandra Urban d , Clifton W. Callaway a , Alexis Steinberg c,d , Jonathan Elmer a,c,d , on behalf of the University of Pittsburgh Post-Cardiac Arrest Service a Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA, USA b University of Pittsburgh School of Medicine, Pittsburgh, PA, USA c Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA d Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA Abstract Background: Electroencephalography (EEG) is commonly used after cardiac arrest. Burst suppression with identical bursts (BSIB) has been reported as a perfectly specific predictor of poor outcome but published case series are small. We describe two patients with BSIB who awakened from coma after cardiac arrest. Methods: We identified two out-of-hospital cardiac arrest (OHCA) patients with coma and BSIB. We determined the etiology of arrest, presenting neurological examination, potential confounders to neurological assessment, neurodiagnostics and time to awakening. We reviewed and interpreted EEGs using 2021 American Clinical Neurophysiology Society guidelines. We quantified identicality of bursts by calculating pairwise correlation coe- cients between the first 500 ms of each aligned burst. Results: In case one we present a 62-year-old man with OHCA secondary to septic shock. EEG showed burst suppression pattern, with bursts consisted of high amplitude generalized spike waves in lock-step with myoclonus (inter-burst correlation = 0.86). He followed commands 3 days after arrest, when repeat EEG showed a continuous, variable and reactive background without epileptiform activity. Case two was a 49-year-old woman with OHCA secondary to polysubstance overdose. Initial EEG revealed burst suppression with high amplitude generalized polyspike-wave bursts with associated myoclonus. She followed commands on post-arrest day 4, when repeat EEG showed a continuous, variable and reactive back- ground with frequent runs of bifrontal predominant sharply contoured rhythmic delta activity. Conclusion: These cases highlight the perils of prognosticating with a single modality in comatose cardiac arrest patients. Keywords: Cardiac arrest Anoxic brain injury Anoxic coma Prognostication Electroencephalography Outcome Burst suppression Introduction Hypoxic-ischemic brain injury from cardiac arrest often results in coma after return of spontaneous circulation (ROSC). 1 Prognostica- tion in this population is challenging, with few highly specific tests available in the first days after ROSC. 2 Electroencephalography (EEG) is a commonly used diagnostic and prognostic test after cardiac arrest. The EEG observation of burst suppression with iden- tical bursts (BSIB) is an ominous finding observed in 10 to 18% of comatose post-arrest patients. 3–7 Initially described by Hofmeijer, et al., 6 the histopathological correlate of BSIB is severe cortical, deep brain and cerebellar necrosis. 8 These observations and available outcomes data support the concept that BSIB is a sign of irrecover- able brain injury. A recent systematic review found BSIB to be a per- fectly specific predictor of poor outcome, 2 but noted broad https://doi.org/10.1016/j.resplu.2021.100151 Received 20 April 2021; Received in revised form 14 June 2021; Accepted 2 July 2021 Ó 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). * Corresponding author at: Iroquois Building, Suite 400A, 3600 Forbes Avenue, Pittsburgh, PA 15213, USA. E-mail address: copplerpj@upmc.edu (P.J. Coppler). diabetes research and clinical practice 7 (2021) 100151 Available online at www.sciencedirect.com Resuscitation Plus journal homepage: www.elsevier.com/locate/resuscitation-plus