Internal carotid artery dissection caused by elongated styloid process.

A 69-year-old man with impaired consciousness, right hemiplegia, and aphasia was admitted to our emergency room for thorough examination. Magnetic resonance imaging (MRI) and 3-dimensional computed tomography (3D CT) scan of the head revealed a cerebral infarction due to dissection of the left internal carotid artery. Contrast-enhanced CT prior to internal carotid artery stenting showed that the left elongated styloid process ran in close proximity to the left internal carotid artery, with a minimum distance of 2 mm. The patient underwent stenting at the internal carotid artery 16 days after disease onset. The patient was referred to our department for left elongated styloid process resection to reduce the risk of further internal carotid artery injury. Resection of the left styloid process through a cervical incision was performed. Six months after surgery, there was no recurrence of the internal carotid artery dissection.