[Paradoxical arterial gas embolism following a direct incisive injury to the skull].

INTRODUCTION: An arterial gas embolism is defined as the presence of air in the arterial circulation. This is an extremely rare cause of stroke that has been described in a multitude of clinical scenarios, generally related to iatrogenic processes. A clinical case is reported in which the arterial gas embolism occurred after a traumatic brain injury, and the most relevant aspects of diagnosis and aetiopathogenesis are reviewed.

CASE REPORT: We report the case of a 52-year-old woman with an open craniofacial wound resulting from an attack with an axe. The initial CT scan found fractures in the left zygomatic, sphenoidal and maxillary arches, as well as pneumocephalus in the cavernous sinuses and the right carotid canal. One hour later, the patient showed a neurological deficit in the right hemisphere, and so a new cranial computed tomography scan with multimodal vascular study was urgently requested, which revealed the mobilisation of the pneumocephalus and ruled out a large vessel arterial occlusion. A shunt study using transcranial Doppler and echocardiography showed the presence of a patent foramen ovale to be the cause of arteriovenous communication that justified an arterial gas embolism. The follow-up CT scan at 48 hours confirmed the appearance of a right parietal ischaemic lesion.

CONCLUSION: This case reflects the simultaneous presence of air in the arterial and venous circulation of the brain, as well as the peripheral communication through a patent foramen ovale. This production mechanism is poorly documented in the literature.