Acute paraplegia: a presenting manifestation of aortic dissection.

Two patients who presented with acute paralysis of the lower extremities as an initial manifestation of aortic dissection are described. The first patient had transient chest pain followed by flaccid paralysis of her lower extremities and severe back pain. In the second patient, sudden paralysis of both legs developed without pain of any sort. The paraplegia completely resolved in a few minutes; however, chest and back pain later ensued. Both patients had a proximal (type I or A) aortic dissection. The first patient's entrance tear in the aortic intima was just above the aortic valve with antegrade propagation, whereas in the second patient, the entrance tear was at the aortic isthmus, with both antegrade and retrograde dissection. Acute cardiac tamponade resulted in sudden deterioration and death in both patients, before any therapeutic intervention could be entertained.