Pathogenesis of spontaneous cervico-cerebral artery dissection. A hypothesis and a review of the literature.

The pathogenesis of spontaneous cervico-cerebral artery dissection remains speculative due to the rarity of histopathological observations, which often correspond to late stage lesions. Transposition of theoretic data from experimental models, study of pathologies with morphological lesions of the same type, and review of some clinical cases, suggest a sequence for the pathological events leading to arterial dissection. Arterial dysplasia, aneurysms and dissections could all result from vascular remodeling in response to endothelial injury. It induces morphologic changes of the internal elastic lamina, smooth muscle cell proliferation, various matrix abnormalities involving the fibrillary components or their enzymatic regulation, arterial wall neoangiogenesis and dissection. Endothelial dysfunction could so play a key role in the imbalance between arterial degenerative and reparative processes and the initiation of cervico-cerebral artery dissection.