ABSTRACT NUMBER: ESOC2026A837 BRAINSTEM AND CERVICAL CORD DYSFUNCTION SECONDARY TO CEREBRAL VENOUS SINUS THROMBOSIS AND DURAL ARTERIOVENOUS FISTULA. A CASE REPORT

Abstract Background and aims Brainstem and upper cervical cord dysfunction caused by venous outflow obstruction is rare and can mimic tumor or ischaemia. We report a case related to sigmoid sinus thrombosis and dural arteriovenous fistula. Methods A 70-year-old woman presented with cervicalgia, dizziness, nausea, gait instability, and blurred vision. Examination revealed horizontal nystagmus, left ptosis, and ataxic gait. CT perfusion showed hypoperfusion in the lower pons and medulla. Brain MRI demonstrated a hyperintense left-sided bulbomedullary lesion on T2/FLAIR extending to the upper cervical cord, without diffusion restriction and with punctate hypointense foci on susceptibility-weighted imaging. Chronic-appearing left sigmoid sinus thrombosis was noted. Results The patient developed progressive cranial nerve deficits, cerebellar signs, and tetraparesis. Angiography confirmed left sigmoid sinus and ipsilateral jugular occlusion with a small dural fistula. Endovascular angioplasty and venous stenting were performed, followed by anticoagulation and antiplatelet therapy. She improved clinically, with follow-up MRI showing resolution of the lesion. At discharge she persisted with dysphagia and mild dysarthria-dysphonia. Control angiography demonstrated partial in-stent rethrombosis and minimal residual fistula, without clinical impact. Conclusions Brainstem and cervical cord dysfunction caused by venous congestion due to dural arteriovenous fistulas or venous sinus thrombosis is uncommon. Case series and reports have documented that prompt diagnosis and endovascular management can lead to reversal of imaging abnormalities and improvement in neurological function. Recognition of this entity is essential to differentiate it from neoplastic or ischemic lesions. Conflict of interest Miriam Ravelo León: nothing to disclose. Figure 1 - belongs to Background and aims Figure 1 - belongs to Methods Figure 1 - belongs to Results Figure 1 - belongs to Conclusions