Development of a dural arteriovenous fistula subsequent to cerebral venous thrombosis by venous hypertension

Abstract

Dural arteriovenous fistulas (dAVF) refer to an aberrant connection between an artery and a vein within the dura. Although the pathogenesis of dAVF is unclear, a link to cerebral venous thrombosis (CVT) has been posited though not fully identified. The current case is the first report demonstrating dAVF formation following CVT according to dynamic changes in the intracranial pressure and venous drainage pattern. This observation provides insight into the pathophysiological association between dAVF and CVT. A 60-year-old woman presented with acute onset of a severe headache and first-onset seizure. Initial magnetic resonance imaging showed an extensive thrombosis in the cerebral venous sinuses. However, there was no evidence of any vascular malformation. Eight months later, she reported dizziness, visual obscurations and pulsatile tinnitus. Follow-up digital subtraction angiography showed multiple dAVFs. Endovascular treatments for the dAVF embolization was performed twice, resulting in the obliteration of the dAVF along with the resolution of her optic disc edema, visual obscurations and tinnitus. The degree and pattern of the venous pressure, not hypoxia-induced growth factors, are the key pathogenic mechanisms of dAVF following CVT. Oral anticoagulants and good adherence do not ensure the prevention of dAVF. Thus, careful clinical observation and follow-up examinations are recommended.

Keywords: Cerebral venous thrombosis; Dural arteriovenous fistula.

Fig. 1

Magnetic resonance venography at the time of presentation shows extensive thrombosis in the superior sagittal sinus, straight sinus, right transverse sinus, and right jugular vein(A, B). Right internal carotid angiogram showed an occlusion of the posterior one-fourth of the superior sagittal sinus and a drainage pattern into the anterior venous system(C). Vertebral angiogram showed a poor visualization of the left transverse sinus(D).

Fig. 2

In the fundoscopic exam at presentation(A), bilateral papilledema was noted. After three weeks(B), the bilateral papilledema had worsened despite the improvement of her symptoms. After the second AVF embolization, her papilledema was resolved with improvement of visual obscuration(C).

Fig. 3

Nine months after initial presentation, right external carotid angiogram showed multiple dAVFs in the torcular herophili, right transverse sinus and right sigmoid-jugular bulb(A). Left external carotid angiogram showed torcular dAVF(B). There was a larger amount of veins drained into the anterior venous system compared to Fig. 1-C(C).