Carbon-monoxide poisoning presenting as an afebrile seizure.

A 1-year-old male who experienced an afebrile seizure and loss of consciousness caused by carbon-monoxide poisoning is reported. His blood gas analysis revealed an elevated carboxyhemoglobin level (up to 25%) and metabolic acidosis. A cranial computed tomography depicted diffuse swelling of the brain. He was promptly treated with hyperbaric oxygen. He recovered fully 8 hours after the onset of the illness. No neurologic deficit was evident during the 8 months of follow-up. Although seizures are generally regarded as a manifestation of severe and near-fatal carbon-monoxide poisoning, an early diagnosis and aggressive hyperbaric-oxygen therapy could result in a good clinical outcome. In a patient presenting with an afebrile seizure, carbon monoxide poisoning should always be considered as one of the etiologies.