Clinical reasoning: a 76-year-old man remaining comatose after cardiopulmonary resuscitation

A 76-year-old man was admitted to the hospital after having a "cardiac arrest" while riding his bicycle and subsequently falling into a canal. Thirty minutes after the accident, he was resuscitated by an ambulance crew. They detected a ventricular tachycardia, which responded to defibrillation. Thereafter, there was a sinus bradycardia, which was treated with atropine and adrenaline. After 30 minutes of resuscitation, there was return of spontaneous circulation (ROSC). At admission to our hospital, the patient was comatose, with a body temperature of 30°C and Glasgow Coma Scale score (GCS) of E1M1V1. According to protocol for presumed acute hypoxic ischemic encephalopathy, he was started on therapeutic hypothermia. The body temperature of the patient was kept at 32°C to 34°C for 24 hours. A few hours after starting hypothermia, twitches around the eyes and mouth were noticed and a neurology consultation was requested. Neurologic examination during hypothermia and under sedation showed a deeply comatose patient with intact pupillary reaction to light bilaterally and present oculocephalic reflex. He had multifocal random twitching movements involving the face, arms, and legs. These shock-like movements were found to increase by external stimuli.