Spontaneous Bilateral Cervical Internal Carotid and Vertebral Artery Dissection in a Japanese Patient without Collagen Vascular Disease with Special Reference to Single-Nucleotide Polymorphisms

Spontaneous cervical artery dissection (sCAD) is a major cause of ischemic stroke in young adults. Frequently, sCAD involves multiple neck arteries, accounting for 13%-28% of the total sCAD cases. However, little is known about factors related to multiple sCAD. In this case, a 52-year-old man was admitted due to headache without aura. There was a personal history of migraine with aura and a family history of similar symptoms. The patient's younger brother had a left vertebral artery (VA) dissecting aneurysm and underwent endovascular occlusion of his parent artery at the age of 48. Magnetic resonance imaging of our admitted patient showed hyperintensities in the right internal carotid artery (ICA) without acute infarction, and magnetic resonance angiography revealed a narrowing of the right ICA. Angiography was then performed, which showed a trace of dissection of the left ICA and both VAs as well as the right ICA. The patient did not fulfill any major criteria of collagen vascular disease such as Ehlers–Danlos syndrome type IV or Loeys–Dietz syndrome. The data in our patient are quite similar to those reported in patients with single-nucleotide polymorphism (SNP) of PHACTR1. Obtaining the patient's informed consent, we analyzed a common SNP variation in the rs9349379[G] allele (PHACTR1), which has been reported to be associated with a lower risk of sCAD.