Transient global amnesia as the presenting feature of heparin-induced thrombocytopenia.

A 57-year-old man developed transient global amnesia within an hour of bolus unfractionated heparin administration on day 4 post-mitral valve replacement. Both immunoglobulin G-specific enzyme-linked immunosorbent assay and serotonin release assay were strongly positive for the antibodies that cause heparin-induced thrombocytopenia. The patient's cognitive functions returned to normal following discontinuation of unfractionated heparin and warfarin and commencement of lepirudin infusion.