Although brainstem infarction is known to cause cardiopulmonary arrest, there are only a few reported cases. We experienced a patient who was brought into our emergency department with cardiopulmonary arrest. After successful resuscitation, she remained comatose, her eyes being fixed in the middle position with no light reflex. She was quadriplegic, but showed occasional right-sided myoclonic involuntary movement. Brain computed tomography performed on the fourth hospital day revealed a diffuse low-density area in the left temporo-occipital lobe. Secondary brainstem infarction due to cerebral hypoperfusion or hypoxemia was ruled out, as other causes of cardiopulmonary arrest were not found. We considered that her cardiopulmonary arrest was caused by brainstem infarction. Cardiopulmonary arrest due to brainstem infarction may be overlooked because of diagnostic difficulty.
