Original Contribution Venous Hypertension as the Cause of Intracranial Hypertension in Patients With Transverse Sinus Dural Arteriovenous Fistula Rebekah M. Ahmed, MBBS(Hons), FRACP, Bryan Khoury, MBBCh, FRANZCR, Mark Wilkinson, MBChB, FRANZCR, Geoffrey D. Parker, MBBS, FRANZCR, G. Michael Halmagyi, MD, FRACP Abstract: We describe 2 patients with transverse sinus CASE REPORTS dural arteriovenous fistulas (DAVFs) who presented with headache and papilledema due to intracranial hypertension. It has been proposed, but never proven, that venous Case 1 hypertension causes the intracranial hypertension in DAVF. The data from our patients support this hypothesis. An A 51-year-old man presented with a 4-month history of left additional factor leading to intracranial hypertension could pulsatile tinnitus. He had an easily palpable left occipital be stenosis of the fellow transverse sinus. artery, a bruit over the left mastoid, and moderately severe, – bilateral papilledema. Visual acuity was 20/20 in each eye, Journal of Neuro-Ophthalmology 2013;33:102 105 fi doi: 10.1097/WNO.0b013e318250575b and visual elds demonstrated enlarged blind spots without © 2012 by North American Neuro-Ophthalmology Society peripheral field constriction. MRA and magnetic resonance venogram (MRV) with auto-triggered elliptic centric or- dered (ATECO) sequences (8) (Fig. 1A) showed occlusion of the left transverse and sigmoid sinuses, with an associated D ural arteriovenous fistula (DAVF) of one transverse DAVF; the occipital artery was dilated and there was subtle sinus can cause intracranial hypertension with papil- cortical venous reflux (Cognard grade IIB) (9). Arteriogra- ledema but without ventriculomegaly, simulating idiopathic phy (Fig. 1B) confirmed a DAVF of the left transverse sinus – intracranial hypertension and leading to vision loss (1 5). with arterial supply from a large transmastoid occipital Cerebral venous sinus hypertension leading to decreased branch of the external carotid artery, the left middle men- fl cerebrospinal uid (CSF) absorption has been proposed ingeal artery, the left internal carotid artery via the – (3 6), although never been proven to be the mechanism. meningo-hypophyseal trunk, and from both vertebral We report 2 patients with intracranial hypertension and arteries via suboccipital branches. The left superior sigmoid DAVFs of one transverse sinus, in whom intracranial sinus was severely attenuated with multiple venous chan- hypertension resolved after embolization of the DAVF. nels, suggesting previous thrombosis. Venous sinus pressure We found that in addition to the DAVF of one transverse measurements were recorded before and after embolization sinus, there was a stenosis of the fellow transverse sinus. We (Table 1). propose that in these patients the lack of even one func- The patient underwent 2 arterial embolization procedures tioning transverse sinus allowed intracranial hypertension to with Onyx. After the second, a left carotid arteriogram dem- develop (7). onstrated no reflux in to cortical veins (Cognard grade IIA). Five months after embolization, the patient still had papilledema but no longer had tinnitus. Lumbar puncture Departments of Neurology (RMA, GMH) and Radiology (BK, MW, showed an opening pressure of 350 mm H20 with normal GDP), Royal Prince Alfred Hospital, Camperdown, Sydney, Australia. CSF contents. Arteriography showed no change in the The authors report no conflict of interest. DAVF. Venography demonstrated that the left transverse Address correspondence to Rebekah M. Ahmed, Department of Neu- rology,RoyalPrinceAlfredHospital,MissendenRoad,Camperdown, sinus was occluded, and there was a swollen arachnoid gran- Sydney, NSW, Australia 2050; E-mail:[email protected] ulation in the right transverse sinus impairing venous flow 102 Ahmed et al: J Neuro-Ophthalmol 2013; 33: 102-105 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Original Contribution FIG. 1. Case 1. A, MRA with ATECO sequences (8) shows extensive, arterialized flow into a very irregular transverse/sigmoid sinus (long arrow) by a dural arteriovenous fistulous channel; left occipital artery (arrowhead); left internal carotid artery (small arrow). B, Late arterial phase from left external carotid artery injection shows extensive dural arteriovenous fistulous channels (black arrow) entering the left transverse/sigmoid sinus with rapid retrograde flow across the torcular into the right transverse/sigmoid sinus (white arrow). The distal left sigmoid sinus is markedly narrowed, with prominent flow into the left vertebral venous plexus (arrowheads). C, Onyx cast within the left transverse/sigmoid sinus and dural channels (white arrow) and coils within the proximal left transverse sinus (black arrow). (pressure gradient: 25 mm Hg). Anterior sagittal sinus pres- Case 2 sure was elevated at 54 mm Hg. An 85-year-old woman with a long history of left pulsatile Six months after arterial embolization, the DAVF was tinnitus was found to have papilledema. Her visual acuity embolized via the right transverse sinus, with 11 hydrocoils was 20/30 in each eye, and visual fields showed enlarged placed in the stump of the left transverse sinus (Fig. 1C). blind spots but no peripheral constriction. MRV disclosed Superior sagittal sinus and torcular pressure decreased to a DAVF draining into the left transverse sinus and distal 29 mm Hg, and the pressure gradient across the arachnoid occlusion of the left sigmoid sinus, with no filling of the left granulation of the right transverse sinus decreased to 5 mm Hg. internal jugular vein. The patient’s papilledema resolved. Arteriography (Fig. 2A) demonstrated a DAVF involving The most recent venogram documented that venous the left transverse sinus with no cortical reflux, and drainage sinus pressure remained stable with a superior sagittal sinus across the torcular into the right transverse sinus and right pressure of 27 mm Hg and a pressure gradient across the internal jugular vein (Cognard grade IIA). Arterial supply was right transverse sinus of 7 mm Hg (Table 1). The patient predominantly via the left occipital and middle meningeal remains well without headache or papilledema. branches, with lesser supply via suboccipital and posterior TABLE 1. Venous Sinus Pressures Recorded Before and After Embolization of DAVF of Transverse Sinus Case 1 Case 2 Post-embolization Post-embolization Pre-embolization 1 Month 9 MonthsPre-embolization Immediate 4 Months ASSS 53 29 27 38 21 16 MSSS 54 29 27 41 21 16 PSSS 54 29 26 42 21 15 Torcular 52 29 24 40 21 15 PTS 52 28 22 43* 21 14 Mid TS 47* 27* 22* 21 12 ATS 42 22* 15 15* 21 11 Sup. sig. sinus 22* 21 15* 19 12 9 Inf. sig. sinus 19 21 14 15 12 9 Jugular bulb 19 21 11 14 12 8 Internal jugular 18 22 9 11 11 7 Right atrium 17 17 7 9 9 6 All pressure measurements are expressed in millimeters of mercury. *Gradient across stenosis. ASSS, anterior superior sagittal sinus; ATS, anterior transverse sinus; MSSS, mid-superior sagittal sinus; PSSS, posterior superior sagittal sinus; PTS, posterior transverse sinus; sup. sig. sinus, superior sigmoid sinus; inf. sig. sinus, inferior sigmoid sinus. Ahmed et al: J Neuro-Ophthalmol 2013; 33: 102-105 103 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Original Contribution FIG. 2. Case 2. A, Arteriogram demonstrates left transverse sinus dural arteriovenous fistula. B, Venogram shows high venous pressure throughout the venous sinuses before embolization and narrowing of the right transverse sinus (arrows). C, Manometry of the venous sinuses reveals a pressure gradient of 28 mm Hg (arrow) across stenosis of the right transverse sinus. D, Four months after embolization, venogram shows normal venous pressures throughout the sinuses and less narrowing of the right transverse sinus. ASSS, anterior superior sagittal sinus; ATS, anterior transverse sinus; MSSS, mid- superior sagittal sinus; PSSS, posterior superior sagittal sinus; PTS, posterior transverse sinus; RA, right atrium; RIJV, right inferior jugular vein; R. Inf. Sig., right inferior sigmoid sinus; R. Sup. Sig., right superior sigmoid sinus. meningeal branches of the vertebral arteries and meningo- Hg, and the pressure gradient across the stenosis in the right hypophyseal tentorial branches. There was no drainage into transverse sinus resolved (Table 1). The patient developed the left sigmoid sinus or left jugular vein. Venography dem- a small intracerebral occipital hemorrhage but made a full onstrated a narrowing of the right transverse sinus together recovery. Papilledema and pulsatile tinnitus resolved. with rapid inflow of unopacified blood via the fistula. The Four months later, venography showed normal venous narrowing was felt to be due to a combination of swelling of sinus pressures (Table 1) and narrowing of the right trans- an arachnoid granulation and elevated intracranial pressure. verse sinus had improved (Fig. 2D). Superior sagittal sinus pressure measured 41 mm Hg (Fig. 2B, 2C; Table 1), with an abrupt drop to 15 mm Hg across the DISCUSSION narrowed segment of the right transverse sinus (Fig. 2C). The DAVF was embolized with Onyx via a transarterial It has been proposed that intracranial hypertension in the approach. Superior sagittal sinus pressure decreased to 21 mm setting of a transverse sinus DAVF is the result of a decreased 104 Ahmed et al: J Neuro-Ophthalmol 2013; 33: 102-105 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction