Stroke caused by cerebral air embolism during endoscopy

Abstract

Intracranial air may occur spontaneously. It can develop as a result of trauma, or it may be introduced iatrogenically. In most reported cases of cerebral air embolism, the air was found in the cerebrospinal fluid-containing compartments, the epidural space, or in the intracranial venous system. Arterial pneumocephalus is uncommon. A case of stroke caused by cerebral arterial air embolism during upper endoscopy is described. The most likely explanation for the embolism is the development of a bronchovenous connection after alveolar rupture. Case report. An 80-year-old man who had undergone a total laryngectomy for a recurrent spinocellular carcinoma underwent upper endoscopy 8 days later because of redbrown sputum and melena. A conventional video-endoscope was used and the procedure was performed without administration of sedative medication. Oxygen saturation and blood pressure remained normal during the procedure. At endoscopy, some fresh blood noted in the pharynx was attributed to the recent surgery. No abnormalities were present in the esophagus, stomach, and duodenum. Toward the end of an otherwise uneventful procedure, the patient developed bronchospasm, became cyanotic, and lost consciousness. He remained unresponsive and developed a flaccid left hemiparesis. There was no evidence of subcutaneous emphysema. Chest radiograph disclosed sequelae of pulmonary tuberculosis on the right side with decreased expansion of the lung and pleural calcification. CT of the brain demonstrated several areas of markedly decreased attenuation compatible with air within the sulci of the right frontal lobe (Fig. 1A). Subsequent magnetic resonance imaging disclosed a recent infarct on the diffusion-weighted images (Fig. 1B and C). Hyperbaric oxygen therapy was not available and no other treatment was initiated. Fever developed during the morning before the endoscopy. Blood cultures were positive for Enterobacter and Streptococcus 2 days after the procedure and treatment was initiated with antibiotics. Evidence of pneumonia was noted on chest radiograph. Cardiac US was normal. Because of a swelling in the neck, US was performed; needle aspiration under US guidance obtained only air. This finding was thought to be related to the development of a fistula after laryngectomy. The patient underwent no additional procedures. He was discharged 1 month after the cerebrovascular insult with a residual left hemiparesis. Discussion. Pneumocephalus, a general term for air within the cranium, may be associated with skull fracture, an intrathecal procedure, cerebral angiography, infection,