Transcranial Doppler sonography: abnormal waveform pattern of intracranial arteries in acute aortic arch dissection.

We describe an interesting pattern of transcranial Doppler (TCD) intracranial blood flow waveforms in a patient with an acute aortic arch type A dissection. A 49-year-old patient presented with a low blood pressure after a syncopal episode, severe chest pain, and mild left hemiparesis. Contrast-enhanced computed tomography revealed the aortic arch dissection and the formation of the false lumen. TCD revealed an abnormal waveform pattern recorded in middle cerebral, internal carotid, and anterior cerebral arteries bilaterally with a pre-systolic sharp wave that gave the appearance of duplicated systolic phase. Our finding adds another interesting pattern of hemodynamic changes in cerebral circulation in patients with acute aortic arch dissections.