Seizures, deep vein thrombosis, and pulmonary emboli in a severe case of May–Thurner syndrome: a case report

May–Thurner syndrome is a vascular disorder caused by the right common iliac artery compressing the left common iliac vein against the lumbar spine, causing distal venous stasis and potentially leading to fibrous change in the venous wall structure. Although May–Thurner syndrome is most commonly discovered in females upon investigation of new-onset deep vein thrombosis, we present the case of an otherwise healthy 29-year-old male with severe May–Thurner syndrome who presented with seizures, bilateral deep vein thrombosis, and diffuse pulmonary emboli. Seizures constituted the earliest presenting symptoms for the patient. Although it is difficult to prove that the patient’s seizures were related to the May–Thurner syndrome, this possible association renders this case extraordinary.

This report describes the case of a 29-year-old previously healthy white male with a severe case of left-sided May–Thurner syndrome that required extensive medical and interventional treatment. The patient experienced two seizures, one month apart, both of which occurred while residing at high altitude. The patient had no prior history of seizures, and epilepsy was ruled out. Three weeks after the second seizure, he presented to the emergency room with hemoptysis, dyspnea, and severe leg pain. Sites of thrombus were confirmed in both legs and diffusely in the lungs. Etiological work-up after treatment with intravenous tissue plasminogen activator revealed May–Thurner syndrome. Hematology workup including genetic testing showed no evidence of coagulopathy. Bilateral common iliac venous stents were placed to attempt definitive treatment. Despite stenting, the patient had another thrombotic event with associated sequelae after discontinuation of anticoagulation. The patient has not had another seizure since the stents were placed. Despite the negative testing, the patient remains on lifelong chemoprophylaxis in the event of an undiscovered hypercoagulopathy.

The care team theorizes that the seizures resulted from hypoxia due to May–Thurner syndrome-induced hemostasis and associated thrombotic events, the high-altitude location of his residence at the time he experienced the seizures, and shallow breathing during sleep. For patients with lower limb venous thrombosis, May–Thurner syndrome should be considered in the differential diagnosis. Endovascular treatment followed by extended prophylactic anticoagulation therapy until the patient is determined to be no longer at risk for thrombosis is recommended. Post-venoplasty thrombosis is a common complication of endovascular treatment of May–Thurner syndrome and should be carefully monitored.