Brain Magnetic Resonance Imaging in Patients with Favorable Outcomes after Out-of-Hospital Cardiac Arrest: Many Have Encephalopathy Even with a Good Cerebral Performance Category Score

Background: The aim of this study was to retrospectively evaluate and analyze the brain magnetic resonance imaging (B-MRI) findings of patients with a favorable neurological outcome following cerebral performance category (CPC) after out-of-hospital cardiac arrest (OHCA) at single university hospital emergency center. Methods: Patients with return of spontaneous circulation (> 24 h) after OHCA who were older than 16 years of age and who had been admitted to the emergency intensive care unit (EICU) for over a 57-month period between July 2007 and March 2012 and survived with a favorable neurological outcome were enrolled. B-MRI was taken after recovery of their mental status. Results: Fifty-two patients among the 305 admitted patients had a good CPC, and 33 patients’ B-MRI were analyzed (CPC 1: 26 patients, CPC 2: 7 patients). Among these, 18 (54.5%) patients had a normal finding on B-MRI. On the other hand, ischemia/infarction/microangiopathy compatible with hypoxic-ischemic encephalopathy (HIE) were found on various brain areas including subcortical white matter (7/13), cerebral cortex, central semiovlae, basal ganglia, putamen, periventricular white matter, and cerebellum. Conclusions: Survivors with a favorable neurological outcome from OHCA showed HIE on B-MRI, especially all of the patients with a CPC 2. More detail neurologic category including brain imaging would be needed to categorize patients with favorable outcome after OHCA.