Surgical disconnection of a hypoglossal canal dural arteriovenous fistula demonstrating rapid progression of medulla oblongata disturbance: illustrative case

BACKGROUND: Dural arteriovenous fistulas of the hypoglossal canal (HCDAVFs) with dominant drainage to perimedullary veins are extremely rare. These patients are prone to develop slow and progressive myelopathy, however, their clinical course has not been fully elucidated. We report an unusual case of HCDAVF in which the patient demonstrated rapid progression of hemiplegia and respiratory insufficiency. OBSERVATIONS: An 82-year-old woman demonstrated motor weakness of the left extremities. T2-weighted magnetic resonance imaging showed a high intensity area in the right medulla oblongata and angiography revealed HCDAVF with dominant drainage to the anterior medullary vein through the anterior condylar vein. Within 3 days, her hemiparesis and respiratory function worsened, and she needed mechanical ventilation. Considering that venous congestion in the medulla oblongata could cause the symptoms, we immediately performed surgical obliteration of the anterior condylar vein. The disappearance of HCDAVF was confirmed by angiography and the patient was weaned from mechanical ventilation 3 days postoperatively. Her left hemiplegia gradually resolved and she was independent in daily life 8 months after the operation. LESSONS: HCDAVFs with dominant drainage to the perimedullary veins can demonstrate rapid progression of medulla oblongata disturbance. Early disconnection should be considered to provide an opportunity for substantial recovery.