Abstract #1395609: Moyamoya Syndrome in a Patient with Thyroid Storm; Role of Plasmapheresis?

Abstract

Moyamoya syndrome is a rare cerebrovascular disorder that can be associated with Graves’ disease. We are presenting a case of young woman with Graves’ disease who developed acute neurologic symptoms. She was treated with plasmapheresis and developed cerebral edema after one procedure. A 28-year-old Hispanic female with 3 years history of Graves’ disease presented to ER with worsening symptoms of thyrotoxicosis. She was not taking antithyroid medications for the previous months. She was admitted for severe hyperthyroidism symptoms. Antithyroid medication was resumed on admission. A day later she developed sudden weakness of the right upper and lower extremities, then she became unresponsive. TSH was < 0.007 uIU/mL [0.36-3.7 mIU/mL], free T4 >8.0 ng/dl [0.76-1.46 ng/dl], total T3 2.75 ng/mL [0.6-1.8 ng/mL]. Brain imaging demonstrated occlusion of the right and left internal carotid arteries consistent with the diagnosis of Moyamoya disease. Treatment for thyroid storm with Propylthiouracil and steroids were initiated. The patient’s mental status did not improve, and plasmapheresis was initiated to improve her symptoms and neurologic outcome. Patient was hemodynamically stable during plasmapheresis with no signs of fluid shift. Several hours after the 1st session, the patient neurologically deteriorated, pupils were fixed and dilated, and corneal reflex was negative. Repeated brain imaging showed cerebral herniation, which ultimately led to brain death. Moyamoya disease is an isolated vascular disorder and a rare cause of stroke. It involves endothelial hyperplasia and narrowing of the proximal portion of the internal carotid arteries, leading to development of abnormal collateral vessels. There are several studies correlating increased thyroid hormone and auto-antibody levels with Moyamoya disease. Therapeutic plasma exchange is used to achieve rapid improvement in symptoms due to the long half-life of thyroid hormones and to eliminate the autoantibodies. It is considered a safe procedure with low incidence of adverse events. However, in patients with severe comorbidities, especially those in the intensive care unit (ICU), the prevalence of adverse events during plasmapheresis is reported to be higher. In this case, no water imbalance was reported during the procedure, and it is unknown whether the plasmapheresis played a role in cerebral edema and herniation. In general, Plasmapheresis is considered a relatively safe for patients hospitalized in ICU in literature reviews, with no reports of cerebral edema as a complication of plasmapheresis in these literatures. However, close monitoring of patients in the ICU is essential for procedure-related safety.