A Long Styloid Process and a Long Way to the Development of Intracranial Hypertension

Compression of the internal jugular vein can lead to venous thrombosis, which can be further complicated by the development of dural arteriovenous fistulas. We present a rare case in which compression of the dominant internal jugular vein by an elongated styloid process triggered a particular series of events leading to the development of intracranial hypertension and papilledema.

Poster 99 A Long Styloid Process and a Long Way to the Development of Intracranial Hypertension Amadeo Rodriguez1, Christine Hawkes2, Bill Wang3, Brian Van Adel2 Division of Ophthalmology and Neurology, McMaster University, Hamilton, Canada, 2Division of Neurology, McMaster University, Hamilton, Canada, 3Division of Neurosurgery McMaster University, Hamilton, Canada 1 Introduction: Compression of the internal jugular vein can lead to venous thrombosis, which can be further complicated by the development of dural arteriovenous fistulas. We present a rare case in which compression of the dominant internal jugular vein by an elongated styloid process triggered a particular series of events leading to the development of intracranial hypertension and papilledema. Description of Case(s): A 44 years old man presented with 3-weeks history of sudden onset of headaches, blurry vision and bilateral pulsatile tinnitus. On exam, there was marked bilateral papilledema. CT venogram revealed a hypoplastic left transverse – sigmoid sinus, with a non-occlusive thrombus involving the posterior superior sagittal sinus, torcula, bilateral transverse and sigmoid sinuses, and bilateral proximal internal jugular vein, more pronounced on the dominant right side. In addition, obvious deformity of the internal jugular vein with compression by the styloid process against the transverse process of C1, was noted bilaterally. Opening pressure was 50 cmH2O with normal CSF constituents. He was started on warfarin and acetazolamide. Thrombophilia work-up was negative. A cerebral angiography revealed a Borden type III B dural arteriovenous fistula of the left sigmoid sinus, which was treated with endovascular embolization. There was improvement of the headaches and pulsatile tinnitus and resolution of the papilledema. Subsequently, he underwent resection of C-1 right transverse process to decompress the dominant right internal jugular vein. Conclusions, including unique features of the case(s): An elongated styloid process as seen in Eagle Syndrome can compress local neurovascular structures, including the internal jugular vein. We hypothesize that in our patient, the compression of the internal jugular vein against C-1 transverse process led to cerebral venous sinus thrombosis. With a thrombosed dominant right venous system, the subsequent development of a dural arterio-venous fistula in the non-dominant sigmoid sinus further contributed to the development of intracranial hypertension. It was successfully treated with endovascular embolization. References: Zhang FL, Zhou HW, Guo ZN, Yang Y. Eagle Syndrome as a cause of Cerebral Venous Sinus Thrombosis. Can J Neurol Sci.;46:344-345, 2019 Cognard C, Casasco A, Toevi M, Houdart E, Chiras J, Merland JJ. Dural Arteriovenous Fistulas as a Cause of Intracranial Hypertension Due to Impairment of Cranial Venous outflow. J Neurol Neurosurg Psychiatry, 65:308-316, 1998 Ahmed RM, Khoury B, Wilkinson M, Parker GD, Halmagyi GM. Venous Hypertension as the Cause if Intracranial Hypertension in Patients with Transverse Sinus Dural Arteriovenous Fistula. J Neuroophthalmol ;33:102-105, 2013. Keywords: vascular disorders, neuroimaging Financial Disclosures: The authors had no disclosures. Grant Support: None. Contact Information: None provided. 2022 Annual Meeting Syllabus | 163