A Case of Delayed Carbon Monoxide Encephalopathy

ABSTRACT

Following are brief statements about the delayed encephalopathy of a patient who recovered without disturbance of consciousness after acute carbon monoxide poisoning. A 72-year-old male was found without consciousness at home and then visited the ER center. Later we learned that the patient was using briquettes as a household heating source. Blood carbon monoxide hemoglobin level was 17.5%. As carbon monoxide poisoning was uncertain after the first interview with the patient, hyperbaric oxygen therapy was not administered at the early stage. After supplying 100% oxygen, the patient recovered consciousness, however, the strength of the lower limb muscle had decreased to class II. The patient showed continued weakening of the lower limb muscle and an increase of CPK; therefore, he was diagnosed as carbon monoxide intoxication and rhabdomyolysis and then admitted to the intensive care unit (ICU) for conservative treatment. During the hospitalization period, continued weakening of the lower limb muscle was observed and he was diagnosed as myopathy after EMG/MCV. However, he suddenly showed altered mentality on the 20th day of hospitalization, and underwent brain MRI. T2 weighted MRI showed typically high signal intensity of both globus pallidus and periventricular white matter; therefore, he was diagnosed as delayed carbon monoxide encephalopathy. This case showed delayed encephalopathy accompanied by rhabdomyolysis and myopathy of a patient who recovered without disturbance of consciousness.