IN GRAVE DANGER: A CASE OF GRAVES THYROTOXICOSIS WITH MOYAMOYA SYNDROME

Abstract

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Graves’ thyrotoxicosis has been associated with Moyamoya syndrome, a condition characterized by diffuse steno-occlusive disease of the cerebral vasculature. Ischemic strokes have been reported in this sub-population often presenting with focal neurological deficits. However, global encephalopathy could be the presenting symptom of this rare association. CASE PRESENTATION: A 43-year-old female with Graves’ disease was admitted with confusion, fevers, and tachycardia. She was diagnosed with sepsis due to urinary tract infection and her biochemical tests were suggestive of severe hyperthyroid state. Initial treatment included steroids, propranolol, and antithyroid agents along with antibiotics. However, on day 2 of admission, she developed right hemiparesis. Computed Tomography Angiograms (CTA) from both days showed evolving multifocal infarcts in bilateral cerebral hemispheres and worsening stenotic disease of anterior cerebral vessels (Figure 1). CT perfusion studies demonstrated markedly prolonged cerebral perfusion bilaterally, a pattern consistent with Moyamoya disease (Figure 2). Due to concern of acute ischemic infarction, the patient was started on vasopressor support to improve neuro-perfusion. Following discontinuation of vasopressors, the patient had further deterioration of neurological status. Magnetic Resonance Imaging (MRI) of the brain depicted evolving watershed infarcts bilaterally (Figure 3). Due to worsening sepsis with labile hemodynamics, plasmapheresis was deferred. Due to persistent comatose state, she was transitioned to comfort care. DISCUSSION: Hemiparesis was often the presenting symptom of this rare association. However, confusion was noted in our patient, not an uncommon finding in thyrotoxicosis. While the mechanism behind this association is unclear, one hypothesis suggests cross-reactivity between Thyroid-Stimulating Hormone (TSH) antibodies and cerebral arteries leading to immune-mediated arteritis. Another hypothesis suggests a demand-supply mismatch in stenosed cerebral vasculature caused by the hypermetabolic state in thyrotoxicosis. The role of accentuating cerebral perfusion with vasopressor support in these patients has not been discussed in literature. Cases of thyrotoxicosis with Moyamoya syndrome report improvement with hormonal control of thyrotoxicosis followed by cerebral revascularization. Malik et al reported improved neurological outcomes in patients managed with early plasmapheresis and aspirin. CONCLUSIONS: The association between Graves’ disease and Moyamoya syndrome is rare and can present as a spectrum of encephalopathy from confusion to coma. When present, it leads to multiple strokes with poor neurological outcomes. Early diagnosis with high index of suspicion is key, as management includes treating thyroid storm and cerebral revascularization. Further studies are required to stratify at-risk populations. Reference #1: Moyamoya Syndrome Associated With Graves' Disease: A Case Report and Review of the Literature. Shaneela M, Andrew N R. J Stroke Cerebrovasc Dis. 2011 Nov;20(6):528-36. Reference #2: Multiple Intracranial Arterial Stenoses Around the Circle of Willis in Association With Graves' Disease: Report of Two Cases. Kazuhiro N, Kiyoyuki Y. Neurosurgery. 2003 Nov;53(5):1210-4; discussion 1214-5. Reference #3: Rapidly Progressive Fatal Bihemispheric Infarction Secondary to Moyamoya Syndrome in Association with Graves Thyrotoxicosis. S.W. Hsu, J.C. Chaloupka and D. Fattal. American Journal of Neuroradiology March 2006, 27 (3) 643-647. DISCLOSURES: No relevant relationships by Ayesha Azmeen, source=Web Response No relevant relationships by Naga Vaishnavi Gadela, source=Web Response No relevant relationships by Viraj Modi, source=Web Response