Characterization of post-anoxic tonic eyelid-opening (PATEO): A poorly-recognized prognostic sign

ABSTRACT Background Post-anoxic myoclonus is a known poor prognostic sign and other post-anoxic spontaneous movements have been reported but poorly described. We aim to describe the electro-clinical phenomenon of post-anoxic eyelid openings in context of its possible prognostic value. Methods We collected clinical data on post-cardiac arrest patients with suspicious eyelid movements noted on continuous EEG monitoring. The eyelid movements captured on the video were correlated to the EEG findings and final clinical outcome. Neuroimaging data was reviewed when available. We also conducted a thorough literature review on this topic. Results A total of 10 patients (5 females) with average age of 56.1 (±14.4) years were included. The mean cardiopulmonary resuscitation duration was 18.9 (±11.3) minutes. Post-anoxic eyelid-opening movements occurred at variable intervals (0.5 to 570 seconds) in each individual. Close examination of eyelid opening (available in 6 patients) revealed them to be tonic movements, lasting an average of 3 (±0.8) seconds and always succeeded the onset of burst of EEG activity in a burst-suppression background. This is a transient phenomenon, lasting a median duration of 30 (IQR 7.75-36) hours. MRI findings in 3 patients demonstrated diffuse cortical ischemic injury with relative sparing of the brainstem. All patients passed away within 2-7 days following cardiac arrest. Conclusion Contrary to previous descriptions, the post-anoxic tonic eyelid-openings (PATEO) are repetitive but non-periodic, non-myoclonic movements. Their close and specific temporal correlation to the burst of EEG activity suggests that this could be considered an ictal phenomenon requiring an intact midbrain based on MRI findings.