Acta Neurochir DOI 10.1007/s00701-017-3135-y CASE REPORT - VASCULAR Dural arteriovenous fistula manifesting as pontine hemorrhage at the craniocervical junction Xuan Liu 1 & Atsushi Ogata 1 & Jun Masuoka 1 & Kohei Inoue 1 & Yukiko Nakahara 1 & Shoko Shimokawa 1 & Yukinori Takase 1 & Yusuke Yakushiji 2 & Hideo Hara 2 & Tatsuya Abe 1 Received: 8 January 2017 / Accepted: 20 February 2017 # Springer-Verlag Wien 2017 Abstract Craniocervical junction (CCJ) dural arteriovenous fistula (DAVF) manifesting as intracerebral hemorrhage is extremely rare. We report the first case of CCJ-DAVF manifesting as pontine hemorrhage. A 69-year-old male presented with a pontine hemorrhage manifesting as a sudden onset of right hemiparesis and dysarthria. Digital subtraction angiography revealed a CCJ-DAVF fed by the meningeal branches of the right vertebral artery. The patient underwent surgical ligation of the cerebral draining veins to prevent re-bleeding. The postoperative course was uneventful. The patient had no neurological deficit after 1 month rehabilitation. Keywords Dural arteriovenous fistula . Craniocervical junction . Intracerebral hemorrhage . Pontine hemorrhage Introduction Dural arteriovenous fistula (DAVF) with cortical venous reflux (CVR) has an annual mortality rate of 10.4% and annual risk rates of 8.1% and 6.9% for hemorrhagic and nonhemorrhagic events, respectively [8]. DAVF at the craniocervical junction (CCJ-DAVF) with CVR manifests as myelopathy or subarachnoid hemorrhage (SAH), with a ratio of 1:1 [1]. Most patients with spinal venous drainage presented with myelopathy, whereas most with intracranial venous * Atsushi Ogata ogata.a24@gmail.com 1 Department of Neurosurgery, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga-shi, Saga 849-8501, Japan 2 Division of Neurology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan drainage presented with SAH [4]. CCJ-DAVF manifesting as intracerebral hemorrhage is extremely rare. Only two cases of CCJ-DAVF manifesting as intracerebral hemorrhage (ICH) have been reported [3, 9]. We report the first case of CCJDAVF manifesting as pontine hemorrhage. Case report A 69-year-old male presented to the emergency room complaining of acute onset of right hemiparesis and dysarthria. He had a history of myocardial infarction and cholelithiasis. Computed tomography (CT) showed left pontine hemorrhage (Fig. 1a). We performed three-dimensional CT angiography (3D-CTA), which showed enlarged veins of the posterior fossa (Fig. 1b). Heavily T2-weighted black-and-white reversed magnetic resonance imaging (MRI) showed enlargement of the left transverse pontine vein (Fig. 2a), and arterial spin labeling (ASL)-MRI showed hyperintensity around the pontine hematoma (Fig. 2c). Right vertebral angiography revealed an arteriovenous shunt at the right side of the craniocervical junction (CCJ) (Figs. 3a, b). The feeding arteries were the meningeal branches of the right vertebral artery at the C1 level. The shunt flow drained upwards into the left petrosal vein via the anterior medullary and the transverse pontine veins (Figs. 3a, b). Feeder aneurysms and venous varices were not indicated. After 16 days from onset of initial bleeding, we performed surgical ligation of the cerebral draining veins to prevent re-bleeding. We performed midline suboccipital craniotomy and C1 laminectomy. An enlarged draining vein was detected near the site of dural penetration of the vertebral artery (Fig. 4a). We identified the draining veins by using intraoperative digital subtraction angiography (DSA) and intravenous indocyanine green angiography. We occluded the draining vein by placing a clip at the nearest Acta Neurochir Fig. 1 (a) Computed tomography showing left pontine hemorrhage. (b) Threedimensional computed tomography angiography showing enlarged veins of the posterior fossa (white arrowhead) point of the dural penetration (Fig. 4b). Postoperative DSA showed disappearance of the arteriovenous shunt at the CCJ (Fig. 3c). The postoperative course was uneventful, and the patient’s right hemiparesis and dysarthria gradually improved. He had no neurological deficit after 1 month rehabilitation. MRI performed 3 months postoperatively revealed normalization of the caliber of the transverse pontine vein and disappearance of hyperintensity on ASL-MRI (Figs. 2b, d). Fig. 2 (a) Preoperative heavily T2-weighted magnetic resonance imaging (MRI) showing enlargement of the transverse pontine vein (circle). (b) Postoperative heavily T2weighted MRI showing normalization of the caliber of the transverse pontine vein (circle). (c) Preoperative arterial spin labeling (ASL)-MRI showing hyperintensity around the pontine hematoma (white arrowhead). (d) Postoperative ASL-MRI showing disappearance of the hyperintensity signal Discussion CCJ-DAVF manifesting as ICH is extremely rare. Only two cases each presenting with cerebellar and medullary hemorrhage have been reported [3, 9]. This is the first report of CCJDAVF manifesting as pontine hemorrhage. Inamasu et al. reported a case of CCJ-DAVF with onset of cerebellar hemorrhage [3]. The patient was primarily diagnosed with hypertensive ICH and was treated conservatively. Four Acta Neurochir Fig. 3 Preoperative (a, b) and postoperative (c) anteroposterior right vertebral angiograms. (a) Arterial phase showing craniocervical junction (CCJ) dural arteriovenous fistula (DAVF) fed by a meningeal branch originating from the right vertebral artery (white arrow indicating the shunting point). (b) Capillary phase showing the shunt flow draining upwards into the left petrosal vein via the anterior medullary vein and the transverse pontine vein (white arrowheads). Neither feeder aneurysms nor venous varices were indicated. (c) Disappearance of CCJ-DAVF months later, the patient suffered SAH and underwent DSA following a diagnosis of CCJ-DAVF. Hypertensive ICH occurs frequently in the cerebellum and pons. In CCJ-DAVF, cerebellar and pontine hemorrhage also occurs. Duffau et al. reported that DAVF with CVR presented a high risk of early re-bleeding, and the rate of re-bleeding within 2 weeks after the first hemorrhage was 35% [2]. Therefore, early diagnosis and treatment are extremely important in patients with DAVF presenting with hemorrhagic stroke. We performed CTA a day after the initial bleeding occurred and achieved an early diagnosis of CCJ-DAVF. Because of higher rates of obliteration for CCJ-DAVF after microsurgery compared to those after embolization [9], we performed microsurgery. Although the patient did not suffer from re-bleeding, we should have performed surgery earlier. Most patients with CCJ-DAVF presenting with SAH had feeder aneurysms or venous varices, and aneurysms or the varices may be the causes of hemorrhage [1, 7]. Here, there were neither aneurysms nor varices, and the dural arteriovenous shunt was located at the right side of the CCJ and drained into the left petrosal vein via the transverse pontine vein. The causative factor for the pontine hemorrhage might be venous congestion because pontine hemorrhage occurred on the same side of the venous drainage. Additionally, preoperative ASLMRI indicated hyperintensity around the pontine hematoma. ASL-MRI is a non-contrast perfusion imaging technique that electromagnetically labels arterial blood proximal to the brain and uses it as a diffusible flow tracer [5]. Noguchi et al. reported the findings of ASL-MRI in patients with DAVF [6]. Hyperintensity in the brain around the shunting areas was observed before operation and is normalized afterwards [6]. The physicians suggested that these findings have demonstrated abundant shunting flow via the fistulas [6]. In the present case, preoperative ASL-MRI may have demonstrated abundant shunting flow in the left pons. Fig. 4 Intraoperative photographs (a) An enlarged draining vein (asterisk) near the site of dural penetration of the vertebral artery was detected. (b) The draining vein was occluded by using a clip at the nearest point of the dural penetration Acta Neurochir CCJ-DAVF can cause not only SAH but also ICH. We should consider CCJ-DAVF as a cause of cerebellar or brain-stem hemorrhage and perform the assessment of vascular disease by a technique such as 3D-CTA or DSA as soon as possible. Compliance with ethical standards Conflicts of Interest The authors declare that they have no conflicts of interest. Human and animal rights and informed consent References 1. 2. 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