Temporary homonymous hemianopsia after epidural blood patch.

We describe a case in which homonymous hemianopsia developed abruptly following an epidural blood patch procedure. The procedure was performed in a patient complaining of post-dural puncture headache after an emergency Cesarean section under spinal anesthesia. Computed tomography and magnetic resonance imaging demonstrated that air bubbles had moved from the prepontine and premedullar cisterns toward the left retrochiasmal region.