Acute Bilateral Stroke in a Moyamoya Patient With High Risk of Thrombosis Due to Multiple Myeloma With Chemotherapy.

Multiple myeloma (MM) is a common hematologic malignancy. Multi-agent chemotherapy and anti-myeloma immunomodulatory drugs increase the incidence of arterial and venous thrombosis. We present a moyamoya patient with MM who had a stroke shortly after induction chemotherapy. We present the case of an adult female patient who arrived at the ER due to automatism seizures, dysarthria, and left hemiparesis. The patient had a medical history of MM and underwent six cycles of induction chemotherapy (cyclophosphamide, dexamethasone, thalidomide, and bortezomib). MRI of the brain showed bilateral watershed ischemic strokes. Angiogram showed occlusion at the supraclinoid segment of both internal carotid arteries consistent with moyamoya. The patient was discharged with full-dose anticoagulation, levetiracetam, and physical therapy. At three years of follow-up, the patient has no recurrent cerebrovascular disease. MM patients treated with thalidomide/lenalidomide in combination with high-dose dexamethasone, doxorubicin, or multiagent chemotherapy should be on anticoagulation for venous thromboembolism (VTE) prophylaxis. There are no clear recommendations for arterial thrombosis prevention. Moyamoya is a vasculopathy characterized by progressive intracranial artery stenosis with a high risk of ischemic stroke, ischemia recurrence, and intracerebral hemorrhage. Despite the risk of intracerebral hemorrhage, we decided on anticoagulation due to the high risk of thrombosis due to MM, multi-agent chemotherapy, and moyamoya.