Brainstem Congestion due to Dural Ateriovenous Fistula at the Craniocervical Junction

Abstract

Dural ateriovenous fistula (DAVF) at the craniocervical junction is rare. We report a patient presenting with brainstem dysfunction as an uncommon onset. Brainstem lesion was suggested by magnetic resonance image study. Angiogram revealed a DAVF at a high cervical segment supplied by the meningeal branch of the right vertebral artery, with ascending and descending venous drainage. Complete obliteration of the fistula was achieved via transarterial Onyx embolization. Clinical cure was achieved in the follow-up period; meanwhile, imaging abnormalities of this case disappeared. Accordingly, we hypothesize that a brainstem lesion of this case was caused by craniocervical DAVF, which induced venous hypertension. Thus, venous drainage patterns should be paid attention to because they are important for diagnosis and theraputic strategy.

Keywords: Brainstem dysfunction; Diagnosis; Dural arteriovenous fistula; Venous congestion.

Fig. 1

Sagittal T2-weight MRI (A) and FLAIR image (B) demonstrating abnormalities from pons to medulla oblongata. C : Sagittal contrast enhanced imaging demonstrating abnormal enhancing lesions located at pontobulbar junction, dorsal oblongata and craniocervical junction. D : Sagittal cervical T2-weight MRI demonstrating abnormal flow void (arrow) at ventral surface from craniocervical junction to cervical cord.

Fig. 2

A and B : Right VA angiogram, posterior-anterior and lateral view, demonstrating DAVF with a meningeal branch originated from radicular artery of the right C2 segment of VA as a feeding vessel, draining via abnormally hypertrophic pontomesencephalic veins (arrows) ascending from basal vein retrogradely into straight sinus and descending into the anterior spinal vein, anterior internal vertebral venous plexus and vertebral artery venous plexus (arrowheads). C : Right VA angiogram immediately after embolization, lateral view, demonstrating complete obliteration of the fistula. D : Right VA angiogram six months after embolization, lateral view, demonstrating complete obliteration of the fistula and disappearance of abnormal venous drainage. VA : vertebral artery, DAVF : dural ateriovenous fistula.

Fig. 3

Follow-up six-month brain MRI. Axial T1-weight imaging (A), axial T2-weight imaging (B), and contrast enhanced T1-weight imaging (C) demonstrating disappeared brainstem abnormal signals.