Cerebral Venous Thrombosis Presenting as Lower Limb Action Myoclonus: A Case Report

Cerebral venous thrombosis is a rare stroke caused by occlusion of venous sinuses or smaller feeding cortical veins. Most cases usually present with headaches, seizures, or focal deficits, but rarely as movement disorders. Herein, we describe a 57-year-old female who presented with action myoclonus in the right lower extremity. Venous thrombosis involving the straight and inferior superior sagittal sinuses was noted on CT angiography. She was treated with apixaban and levetiracetam, with good control of the myoclonic jerks. However, she later developed an action myoclonus and weakness in the left leg, attributed to a new-onset venous infarction. Apixaban was shifted to enoxaparin, with the cerebral angiography showing clearing of the thrombosis in the previously affected sinuses. Workup for prothrombotic conditions predisposing to venous thrombosis was unremarkable. Anticoagulation with warfarin and a higher dose of levetiracetam eventually afforded a gradual improvement of the weakness and complete resolution of her myoclonus. Although rare, cerebral venous sinus thrombosis should also be considered as an acquired cause of action myoclonus.