Styloidogenic Internal Carotid Artery Dissection Presenting as Severe New-Onset Headache in a Young Adult.

Cervical artery dissection is a leading cause of stroke in young adults and may present with isolated headache without objective focal neurological deficit. Vascular Eagle syndrome (also known as stylocarotid artery syndrome) is a specific variant of Eagle syndrome, characterised by an elongated styloid process that may mechanically irritate or compress the internal carotid artery, predisposing it to dissection. We report a case of a 31-year-old man who presented with severe new-onset headache and was found on CT angiography to have internal carotid artery dissection in the context of an elongated styloid process consistent with vascular Eagle syndrome. His brain MRI demonstrated no acute infarction. He was managed with antiplatelet therapy and discharged with stroke follow-up and planned interval CT angiography. This case highlights the importance of considering cervical artery dissection in young patients with severe headache even without neurological deficit, the diagnostic value of CT angiography in identifying both the dissection and underlying structural contributors, and the clinical significance of recognising stylocarotid artery syndrome (vascular Eagle syndrome) as a potentially reversible mechanical risk factor triggering this vascular phenomenon.