Spontaneous dissection of the cervical internal carotid artery: correlation of arteriography, CT, and pathology

To investigate the clinical significance of lucent defects in computed tomography (CT) scans of the cervical carotid artery plaque, we studied 95 patients with recent symptoms of hemispheric ischemia. Using multiple linear regression analysis, we estimated the strength of the association of symptoms with laterality of carotid artery lucent lesions, stenoses, and ulcerations observed in CT scans. Hemispheric symptoms correlated strongly with ipsilateral carotid lucent lesions (partial p<0.025) and with ipsilateral severe (> 75%) carotid stenosis (partial p< 0.025). Carotid artery ulcerations had a weaker association (partial p<0.1), and stenoses of mild and moderate degrees showed none. The overall performance of all three plaque complications was highly significant (p< 0.005). The lucent defect indicates a morphologic change in the carotid plaque that plays an important role in the development of symptoms of hemispheric ischemia. This is in agreement with the notion that the lucent defect is the image of intraplaque hemorrhage and/or necrosis, which are complications central to the development of symptomatic carotid disease. (Stroke 1988;19:723-727) H igh-resolution computed tomography (CT) of the cervical region permits a low-risk evaluation of the carotid vessels and atheromatous plaque formations, including intramural and extramural histopathologic plaque complications.112 In contrastenhanced cervical CT images, carotid vessels are located immediately lateral and posterior to the pharyngeal cavity and medial to the sternocleidomastoid muscle ( Figure 1). The internal carotid artery is usually found lateral and posterior to the external carotid, although occasional variations occur. In normal individuals, CT images of the vascular wall merge with the image of the contrast-filled lumen and are not observed as a distinct structure. Carotid atheromatous plaques are identified by the irregular, often constricted and commonly calcified contour of the vascular wall, encircling a contrast-filled lumen. Irregularities are more prominent at the carotid bifurcation or in the proximal segment of the internal carotid artery. In CT images of the cervical carotid plaque, it is possible to identify extramural morphologic changes such as stenosis, ulceration, and occlusion, as well as intramural lesions manifested by hyperdense changes indicative of calcification, and lucent, hypodense defects (Figures 2 and 3). Lucencies indicate an intraplaque histologic change that can be observed only by CT. They are suggestive of arterial subintimal hemorrhage or plaque necrosis, which are both complications that play an important role in the development of cerebral ischemia. Should that be the case, plaque lucencies could serve as markers or predictors of risk of stroke. Received September 14, 1987; accepted December 4, 1987. To investigate the clinical significance of intramural lucent defects observed in contrast-enhanced CT images of the cervical carotid plaque, we studied patients with symptoms of hemispheric ischemia. The streng...

Section: Discussionsupporting

confidence: 80%

Computed tomography of the cervical carotid artery: significance of the lucent defect.

Culebras

Magaña

Cacayorin

1988

“…The intramural hematoma may expand outward toward the adventitia to create an aneurysmal sac or dissecting aneurysm. These aneurysms may harbor thrombi 1,11,163,[173][174][175][176][177] (Figures 1-3). The intramural hematoma is located within the layers of the tunica media but may be eccentric and directed toward the intima (subintimal dissection) or toward the adventitia (subadventitial dissection).…”

Section: Pathologymentioning

confidence: 99%

Cervical Arterial Dissections and Association With Cervical Manipulative Therapy

Biller¹,

Sacco²,

Albuquerque³

et al. 2014

175

3155Purpose-Cervical artery dissections (CDs) are among the most common causes of stroke in young and middle-aged adults.The aim of this scientific statement is to review the current state of evidence on the diagnosis and management of CDs and their statistical association with cervical manipulative therapy (CMT). In some forms of CMT, a high or low amplitude thrust is applied to the cervical spine by a healthcare professional. Methods-Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee and the American Heart Association's Manuscript Oversight Committee. Members were assigned topics relevant to their areas of expertise and reviewed appropriate literature, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge. Results-Patients with CD may present with unilateral headaches, posterior cervical pain, or cerebral or retinal ischemia (transient ischemic or strokes) attributable mainly to artery-artery embolism, CD cranial nerve palsies, oculosympathetic palsy, or pulsatile tinnitus. Diagnosis of CD depends on a thorough history, physical examination, and targeted ancillary investigations. Although the role of trivial trauma is debatable, mechanical forces can lead to intimal injuries of the vertebral arteries and internal carotid arteries and result in CD. Disability levels vary among CD patients with many having good outcomes, but serious neurological sequelae can occur. No evidence-based guidelines are currently available to endorse best management strategies for CDs. Antiplatelet and anticoagulant treatments are both used for prevention of local thrombus and secondary embolism. Case-control and other articles have suggested an epidemiologic association between CD, particularly vertebral artery dissection, and CMT. It is unclear whether this is due to lack of recognition of preexisting CD in these patients or due to trauma caused by CMT. Ultrasonography, computed tomographic angiography, and magnetic resonance imaging with magnetic resonance angiography are useful in the diagnosis of CD. Follow-up neuroimaging is preferentially done with noninvasive modalities, but we suggest that no single test should be seen as the gold standard.

“…1215 A mural thickening, eccentric in distribution and describing a spiral around the vessel from level to level, is reported by Petro et al 13 in five stenotic-type dissections of the internal carotid arteries. More recently, Dal Pozzo et al 15 have described a picture composed of a narrowed central or eccentric enhancement (residual lumen) surrounded by a hypodensity (mural hematoma), itself surrounded by a thin annular contrast enhancement in 2 of 3 dissected internal carotid arteries.…”

Section: Discussionmentioning

confidence: 85%

Magnetic resonance imaging and dynamic CT scan in cervical artery dissections.

Züber

Meary

Méder

et al. 1994

127

The typical magnetic resonance imaging picture of arterial dissection, namely, a narrowed eccentric signal void surrounded by a semilunar signal hyper-intensity (corresponding to the mural hematoma) on T1- and T2-weighted images, has been repeatedly reported, but the sensitivity of magnetic resonance imaging for the diagnosis of cervical dissection is poorly known. Another technique, dynamic computed tomography, may provide evidence of mural hematoma, but there has been no systematic evaluation of this technique. The aims of this study were to assess both the sensitivity of routine 0.5-T magnetic resonance imaging for the detection of a typical picture of cervical artery dissection and the value of dynamic computed tomographic scans to provide evidence of dissecting hematoma. Fifteen consecutive patients with angiographically confirmed extracranial internal carotid (n = 9) or vertebral (n = 10) dissections were studied using a standardized 0.5-T spin-echo magnetic resonance imaging protocol with axial slices. Twelve of these patients had dynamic computed tomographic scans at the site of the dissection suggested by angiography. A typical magnetic resonance imaging picture of cervical artery dissection was observed in 12 of 15 (80%) patients and in 13 of 19 (68%) dissected vessels. The sensitivity of magnetic resonance imaging was higher in internal carotid (78%) than in vertebral (60%) dissections and in stenotic-type dissections (85%) than in occlusive or aneurysmal-type dissections. The dynamic computed tomographic scan showed the mural hematoma in 11 of the 12 (92%) patients and in 12 of 15 (80%) dissected vessels. Routine 0.5-T magnetic resonance imaging with axial slices is a sensitive technique for the diagnosis of dissection, but in about 20% of patients with cervical artery dissection magnetic resonance imaging will demonstrate no typical abnormality. Dynamic computed tomographic scans are a sensitive neuroimaging procedure to confirm the presence of the mural hematoma, but it needs to be directed by prior angiography.