Bilateral Vein of Trolard Thrombosis Presenting with Seizure and Minimal Deficits: A Rare Case Report

Isolated cortical vein thrombosis is a rare subtype of cerebral venous thrombosis with highly variable clinical and radiologic manifestations that frequently delay diagnosis. Bilateral thrombosis of the veins of Trolard is exceptionally uncommon, with only a few cases reported in the literature. We report a 64-year-old right-handed man who presented after being found unresponsive with suspected seizure. Although his neurological examination was normal at evaluation (NIHSS 0), noncontrast CT demonstrated subtle bilateral cortical vein hyperdensities (cord sign). Subsequent MRI and MR venography confirmed bilateral thrombosis of the veins of Trolard with associated venous congestion and a small sulcal subarachnoid hemorrhage. The patient was treated with therapeutic anticoagulation and levetiracetam. The patient achieved an excellent functional outcome (modified Rankin Scale score of 0). At 3-month follow-up, he remained neurologically intact without recurrent seizures. Follow-up MRI demonstrated improvement of the cortical FLAIR abnormality, and MR venography showed significant interval improvement in the bilateral vein of Trolard thromboses with residual short-segment nonocclusive filling defects, consistent with partial venous recanalization. This case expands the recognized clinical spectrum of the bilateral vein of Trolard thrombosis by demonstrating that extensive bilateral cortical venous involvement may present predominantly with seizure despite a normal neurological examination (NIHSS 0). Early recognition of subtle CT findings, confirmation with dedicated venous imaging, and prompt anticoagulation can result in excellent clinical recovery and favorable radiographic evolution.