Persistent Hypoglossal Artery as a Rare Anatomical Variation Mimicking Carotid Artery Aneurysm: A Case Report.

We present a case of a rare vascular variation of the persistent hypoglossal artery (PHA) in a 57-year-old Caucasian female patient with a medical history of poorly controlled hypertension, headaches, diabetes mellitus, and depression. This anatomical variation was initially misdiagnosed as an internal carotid artery (ICA) aneurysm during the extracranial carotid Doppler imaging conducted due to nonspecific symptoms of cerebrovascular insufficiency, manifesting as coordination disturbances. PHA is one of the four vertebrobasilar anastomoses, originating from the cervical segment of the ICA. Together with the hypoglossal nerve, the meningeal branch of the ascending pharyngeal artery, and an emissary vein from the basilar plexus, it traverses the hypoglossal canal and enters the posterior cranial fossa, where it joins the basilar artery. This artery typically involutes during embryonic development but can persist into adulthood. If present, PHA is most often asymptomatic; however, it can be associated with pathological conditions such as atherosclerosis, cerebral ischemia, aneurysms, and arteriovenous malformations. This case highlights the diagnostic challenges posed by this anatomical variation and underscores the importance of further investigations in confirming accurate vascular anatomy. Here, we discuss the diagnostic criteria for PHA, its clinical significance, and therapeutic modalities.