Spontaneous Cervical Artery Dissections

Review Article

Austin J Clin Neurol 2014;1(3): 1012.

Spontaneous Cervical Artery Dissections

Steinsiepe VK, Jung S, Goeggel Simonetti B and Arnold M*

Department of Neurology, Bern University Hospital, Switzerland

*Corresponding author: Marcel Arnold, Department of Neurology, Bern University Hospital, Freiburgstrasse 10, 3010 Bern, Switzerland

Received: March 19, 2014; Accepted: June 11, 2014; Published: June 15, 2014

Abstract

Spontaneous cervical artery dissection is a rare cause of stroke in general, but it is a major cause of stroke in young adults. While connective tissue abnormalities and minor trauma may be involved, to this date, its pathogenesis remains unclear. Genetic mutations may also play a role and a seasonal pattern as well as associations with migraine, high plasma homocysteine and chiropractic manipulative therapy have been found. Clinical presentation comprises of local and, more importantly, ischemic symptoms, but only recently randomized controlled trials have been started to assess thrombolysis and antithrombotic treatment. Because early diagnosis could possibly prevent or alleviate ischemic manifestations, these patients should be assessed quickly and accurately. The following review aims to provide a well-rounded insight into the disease.

Keywords: Cervical artery dissection; Spontaneous; VAD

Abbreviations

CAD: Cervical Artery Dissection; ICAD: Internal Carotid Artery Dissection; VAD: Vertebral Artery Dissection

Introduction

First pathological reports of cervical artery dissection (CAD) date back as far as 1872, but the condition was only recognized as a cause of stroke as late as the mid-1950s [1]. While at first considered a rather rare disease [2], CAD has gained a lot of attention over the past decades and is now recognized as one of the most important etiologies of stroke in young people [3], accounting for more than 2% of strokes in the general population and about 20% in adults under the age of 45 [2,4,5], therefore being an equally frequent cause of stroke as cardiac embolism [3].

Pathology

CAD is defined by the presence of an intramural hematoma in a cervical artery, mostly the internal carotid artery or the vertebral artery. The relatively high frequency of dissections in cervical arteries compared to dissections in other arteries of the same diameter maybe partially explained by their greater mobility. This led to the recognition of CAD as a more or less independent pathology [2].

Two kinds of pathomechanisms have been postulated to lead to CAD: Either, for unknown reasons, the tunica intima tears apart, and blood enters through the tear and forms a false lumen within the tunica media with the subsequent development of an intramural hematoma [2]. Or, after initial rupture of the vasa vasorum, the primary formation of an intramural hematoma causes the intimal tear [6].

The dissection itself usually appears distally to the tear [5,7]. A subintimal entry of blood is thought to lead to primary dilatation of the vessel wall into the original vessel lumen causing stenosis or occlusion while a sub-adventitial hemorrhage would primarily dilate outwardly and form a so-called dissecting aneurysm [2,8]. While these aneurysms sometimes have been referred to as pseudoaneurysms or false aneurysms, these terms should not be used because a pseudoaneurysm is not contained by the arterial wall, but by the surrounding tissue, in contrast to the dissecting aneurysm, the boundaries of which always partially include the blood vessel [2,8].

Cervical artery dissections are divided into three subtypes (Figure 1): They may present as stenotic in about half of all cases and occlusive as well as of dissecting aneurysmal form in about one-fourth each, but numbers may vary and combined forms occur [8-10]. The higher the degree of stenosis, the more likely are ischemic events, while aneurysmal forms are thought to cause more local symptoms [10,11]. Aneurysmal dilatation occurs usually in the sub-petrous segment of the internal carotid artery [10]. Aneurysms are described as either saccular (pouchy) or fusiform (dilating) [8].