Abstract
Cerebral air embolism is a catastrophic phenomenon described in trauma, vascular intervention, barotrauma related to positive pressure ventilation, SCUBA diving and rarely air travel.1 A 71-year-old woman was found unrousable at the end of an uneventful three-hour flight on a small aircraft. On examination, she was obtunded, without lateralising or brainstem signs, and a possible seizure was witnessed. She was loaded with antiseizure medication and intubated for airway protection.
Initial CT stroke protocol showed bilateral frontal lobe attenuation without perfusion deficit or vessel occlusion. Lumbar puncture revealed elevated protein with normal cell count, and EEG showed generalised, bifrontal predominant asymmetric slowing. The clinical impression was of acute encephalopathy; infective, toxic and metabolic screens were unremarkable, no further seizures were observed. Antibiotics and antivirals were discontinued, autoimmune aetiology was considered, and IVIG commenced. Serial MRI Brains demonstrated progressive bilateral cortical and thalamic T2 changes with initial areas of enhancement and progressive milary cortical susceptibility foci on SWI. Despite treatment, there was minimal initial recovery. Autoimmune markers in blood and CSF were negative. CT chest to exclude malignancy revealed a right pneumatocele. We concluded diffuse ischaemic injury had occurred secondary to air embolism. No intravascular gas was seen on imaging review. Our patient was outside the time frame for hyperbaric oxygen therapy. She slowly recovered but was discharged with significant deficits to a nursing home.
This case highlights a rare phenomenon due to atmospheric pressure changes during flight in patients with pulmonary pneumatoceles/cysts. Timely recognition is essential to facilitate treatment.2
References
Edwardson M, Wurth D, Lacy JM, Fink J, Becker K. Cerebral air embolism resulting in fatal stroke in an airplane passenger with a pulmonary bronchogenic cyst. Neurocritical Care. 2009;10(2):218–21.
Farshchi Zarabi S, Parotto M, Katznelson R, Downar J. Massive ischemic stroke due to pulmonary barotrauma and cerebral artery air embolism during commercial air travel. The American Journal of Case Reports. 2017;18:660–4.
