Carotid dissections and vertebral dissections cause ~20% of strokes in patients <45 years old and can be caused by direct trauma to or round the neck, whiplash injury, violent coughing, strenuous events like exercise or childbirth, or occur spontaneously. Arterial dissections are also more common in patients with connective tissue disease such as Marfan, Loeys–Deitz, and Ehlers–Danlos syndromes; osteogenesis imperfecta; fibromuscular dysplasia; and 𝛼1-antitrypsin deficiency. Carotid dissections are much more common than vertebral dissections, comprising ~70–80% of all cervicocerebral arterial dissections, and vertebral dissections comprising ~15%.