Eagle syndrome is a rare disorder most associated with an elongated styloid process causing cervicofacial pain, dysphagia, or carotid compression. A lesser-known variant, venous Eagle syndrome, involves internal jugular vein (IJV) compression, typically between the styloid process and the C1 transverse process, resulting in impaired cerebral venous outflow. This form is increasingly recognized in headache pathophysiology, yet the role of C1 transverse process osteotomy as a definitive treatment remains underreported.

A 57-year-old woman with no significant medical history presented with intractable right-sided headaches and facial pain persisting for over a decade. The headaches were near-daily, disabling, and resistant to multiple medications and conservative measures. CT brain and CTA of the head and neck revealed no acute findings or vascular malformations. Given her refractory symptoms, diagnostic cerebral venography with manometry was performed, revealing bilateral IJV stenosis from compression between the styloid process and the C1 transverse process, worse on the left. Dynamic occlusion occurred with certain neck positions. Manometry confirmed a >4 cm H₂O pressure gradient, indicating significant hemodynamic obstruction and resultant venous congestion contributing to headache generation.

The patient underwent microsurgical resection of the left C1 transverse process with stereotactic navigation, without styloidectomy. The procedure was uncomplicated, and she experienced complete and sustained resolution of her headaches and facial pain, maintaining full relief at six-month follow-up without medications.

This case illustrates the importance of considering venous Eagle syndrome in chronic refractory headache. When bony impingement at C1 contributes to IJV compression, C1 transverse process osteotomy alone can restore venous drainage and relieve symptoms. Manometry provides critical confirmation of physiologic significance, guiding surgical decision-making in this rare but treatable cause of headache. The findings broaden the understanding of cranial venous physiology in pain generation and support expanding neurology’s diagnostic lens beyond purely arterial or neurochemical paradigms.