Progressive headache and neck pain associated with neck rotation due to a congenital external carotid-jugular arteriovenous fistula: illustrative case.

Background: Congenital external carotid-jugular arteriovenous fistulas (AVFs) are often diagnosed based on a pulsatile neck mass. Patients rarely complain of headaches or neck pain.

Observations: A 45-year-old woman with no history of trauma had been diagnosed with a congenital cervical external carotid AVF 10 years earlier. At that time, only a pulsatile neck mass in the right neck had been observed, and she had been managed conservatively. Over the next 10 years, the right neck mass had enlarged, and she started experiencing unbearable headaches and neck pain when she turned her head. Angiography images showed that the outflow veins, including the external and internal jugular veins, were more dilated and tortuous than they had been 10 years earlier. During neck rotation, the internal jugular vein constricted, causing intracranial venous reflux. Complete occlusion of the shunt was achieved with coils and n-butyl-2-cyanoacrylate. Immediately after surgery, the pulsation in the right neck, the unbearable headaches, and neck pain on neck rotation resolved.

Lessons: Even in adults with congenital cervical external carotid AVFs that have been managed as simple neck masses, progressive dilatation and tortuosity of the outflow veins can, over time, lead to venous reflux during neck rotation and can cause unbearable headaches and neck pain. https://thejns.org/doi/10.3171/CASE24407.