Thrombotic Thrombocytopenic Purpura Masquerading as Acute Ischemic Stroke

Thrombotic thrombocytopenic purpura (TTP) is a hematologic disorder that results in widespread clotting due to a deficiency of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) protease. This leads to excessive von Willebrand factor (VWF) protein-platelet multimers. Due to platelet consumption, platelet levels fall, resulting in thrombocytopenia. We examined a case of a 31-year-old female with no significant medical history who presented with expressive aphasia and paresthesias and was sent to the Emergency Department for a stroke workup. Imaging was negative for ischemic or hemorrhagic stroke; however, a complete blood count (CBC) was consistent with anemia and thrombocytopenia, resulting in a high suspicion for TTP. She was admitted to the intensive care unit and given fresh frozen plasma and packed red blood cells. Plasma exchange therapy was initiated, and her aphasia and paresthesias began to improve. The ADAMTS13 level returned at less than 5%, which prompted the initiation of rituximab therapy. During her 36-day hospital stay, she continued to receive daily steroids and plasma exchange and a total of four courses of rituximab. Her platelets steadily climbed, and she was discharged with instructions to follow up with outpatient hematology. TTP is a thrombotic microangiopathy that results in microscopic blood clots anywhere in the body, including the cerebral arteries. This results in the neurologic abnormalities that are often seen in TTP. Because TTP is a rare disease, treatment modalities are still scarce but include steroids, plasma exchange therapy, and rituximab. Novel therapies are on their way, one being caplacizumab, a monoclonal antibody that inhibits VWF from interaction with glycoprotein 1b. A concern highlighted by this case is the exclusion criteria for the administration of tissue plasminogen activator (TPA). As this patient presented with stroke symptoms and a negative head CT, TPA would have been administered had a CBC not returned showing evidence of TTP. This highlights the importance of strict adherence to the American Heart Association/American Stroke Association guidelines that include ensuring that the platelet count is >100,000 prior to the initiation of TPA.