Association of cervical artery dissection with connective tissue abnormalities in skin and arteries

Abstract

Spontaneous cervical artery dissections (sCAD) often occur in otherwise healthy individuals without known risk factors for stroke and frequently develop spontaneously without relevant trauma. An underlying arteriopathy leading to a so-called 'weakness of the vessel wall' and predisposing certain individuals to dissection has often been postulated. Therefore, the morphology of connective tissue, a main component of vessel wall and environment, was investigated in carotids and skin. While the overall morphology of dermal connective tissue is normal, about half of patients with sCAD show mild ultrastructural connective tissue alterations. These ultrastructural morphological aberrations can be designated either as 'Ehlers-Danlos syndrome (EDS) III-like', resembling mild findings in patients with the hypermobility type of EDS (EDS III); or coined 'EDS IV-like' with collagen fibers containing fibrils with highly variable diameters resembling mild findings in vascular EDS; or the abnormalities are restricted to the elastic fibers (with fragmentation and minicalcifications) without significant alterations in the morphology of the collagen fibrils. These findings had some similarity with the morphology found in heterozygous carriers of pseudoxanthoma elasticum. A grading scale according to the severity of the findings has been introduced. Similar connective tissue abnormalities were detected in some first-degree relatives of patients with sCAD showing hereditary at least in a subgroup. They can serve as a phenotypic marker for further genetic studies in patients with sCAD and large families to possibly identify the underlying basic molecular defect(s). Very few of patients (<5%) with sCAD and connective tissue abnormalities have clinical manifestations of skin, joint, or skeletal abnormalities of a defined heritable connective tissue disorder. In specimens of arterial walls of carotid, aortic, and renal arteries of patients with sCAD, pronounced systemic, histopathological, and ultrastructural abnormalities were detected with elastic fiber fragmentation and medial degeneration, described before only in a few patients with known hereditary connective tissue diseases such as the Marfan syndrome. We hypothesize that a major part of sCAD cases represents a manifestation of a connective tissue disorder with a vascular phenotype.