Intracranial dissections: A pictorial review of pathophysiology, imaging features, and natural history.

Intracranial artery dissections (IAD) are uncommon entities associated with high rates of morbidity and mortality. Certain ethnic groups and patients with underlying connective tissue disorders may be at a higher risk of developing IAD, but these relationships are unclear due to the condition's rarity. Patients often present with a prodromal headache followed by subarachnoid hemorrhage (SAH) or ischemic stroke. Imaging findings are critical to establishing the diagnosis, as the lesions have a myriad of presentations based on the severity, location, and timing of the dissection. Lesions that present with ischemia are at high risk for future ischemia but low risk of future hemorrhage, whereas lesions, which present with hemorrhage have a high rate of re-bleeding if left untreated. There are no evidence-based guidelines for medical or surgical management. Several endovascular and surgical techniques have been used to prevent or treat hemorrhage by ligating the parent artery or reconstructing the vessel wall. Outcomes are generally poorer in patients with IAD than cervical artery dissection, particularly in those who suffer SAH.