Acute aortic dissection mimicking basilar artery occlusion in a patient presenting with sudden coma.

A 77-year-old female suddenly became comatose. Examination at the emergency room revealed stable vital signs and bilateral positive plantar reflexes but absent brainstem reflexes. Basilar artery occlusion was initially diagnosed and recombinant tissue plasminogen activator was administered. However, her blood pressure dropped after thrombolysis. A chest CT scan showed aortic dissection extending to the bilateral common carotid arteries. Her follow-up brain CT scan disclosed infarctions over bilateral carotid territories without brainstem involvement. Aortic dissection should be listed as a possible diagnosis in a patient who presents with a sudden coma mimicking basilar artery occlusion. Detailed clinical examination and discussion might lead to the correct diagnosis and avoid inadvertent thrombolysis in the emergency room.