Morphometric analysis of collagen fibrils in skin of patients with spontaneous cervical artery dissection.

BACKGROUND AND AIM: The aetiopathogenesis of spontaneous cervical artery dissection (sCAD) is largely unknown. Electron microscopic (EM) examination of skin biopsies of patients with sCAD revealed very subtle pathological changes of dermal connective tissue in about half of these patients leading to the hypothesis of an underlying connective tissue disorder. However, connective tissue abnormalities did not allow clear discrimination between patients and controls in our hands. Therefore, we sought to establish an objective basis for the assessment of connective tissue abnormalities in patients with sCAD using standardised morphometric assessment of collagen fibrils. METHODS: In this study a blinded examination was performed of collagen in skin biopsies and it sought parameters which are able to discriminate between patients with sCAD and controls. Various morphometric parameters were compared between patients with sCAD (n = 20) and control subjects (n = 18). RESULTS: Previously described "flower-like" collagen fibrils in skin biopsies were extremely rare in patients and controls and did not discriminate between the groups. However, they were abundant in the skin biopsy of a patient with Ehlers-Danlos syndrome type III (EDSIII) used as a reference. Morphometric parameters such as collagen fibril diameter, fibril density and relative fibril area did not discriminate between patients and controls on an individual basis, but the mean diameter of collagen fibrils in the skin was lower in patients with sCAD compared with controls while fibril density was higher resulting in nearly equal fibril areas per unit of area (relative fibril area) comparing both groups as well as individuals. CONCLUSIONS: Blinded pathological and morphometric analysis of collagen fibres in skin biopsies was, in our hands, unable to discriminate reliably between patients with sCAD and controls on an individual basis but did show differences in collagen fibril morphometry on a group basis. Furthermore, systematic and blinded pathological studies of skin biopsies in patients with sCAD and controls are needed.

Do extracellular-matrix-regulating enzymes play a role in cervical artery dissection?

BACKGROUND: An underlying extracellular matrix defect is suspected in patients with spontaneous cervical artery dissection (SCAD). We test the hypothesis that levels of matrix metalloproteinase (MMP) 2 and 9, and elastase, extracellular-matrix-regulating enzymes involved in the vascular wall remodeling process, are modified in SCAD. METHODS: The authors prospectively and consecutively recruited 47 patients with SCAD and 52 patients with an ischemic stroke from another cause in 2 centers, and measured their plasmatic level of MMP-2, MMP-9 and elastase 3 months after the vascular event. RESULTS: Patients with SCAD had a higher mean MMP-2 level compared with controls [379.2 (SD = 76.6) vs. 355.9 (75.1) ng/ml; p = 0.11] and had more frequently a high level of MMP-2 (>326 ng/ml) than controls (77.8 vs. 54.5%, p = 0.019). This association was stronger in patients with multiple dissection than single artery dissection or controls (84.6, 75.0 and 54.5%, respectively, p = 0.018). The levels of MMP-9 and elastase were similar in cases and controls, but more patients had a high level of these enzymes in the group with multiple dissections than in the group with single artery dissection or controls. CONCLUSION: Patients with SCAD have higher plasma levels of proteases, particularly MMP-2. The association is stronger in patients with multiple dissections.

Elevated inflammatory laboratory parameters in spontaneous cervical artery dissection as compared to traumatic dissection: a retrospective case-control study.

Several studies have reported infection as a possible risk factor for cervical artery dissection (CAD). We retrospectively analyzed several inflammatory parameters of CAD patients with the aim of detecting differences between spontaneous (n = 25) and traumatic (n = 18) CAD. In this case-control study, we observed significantly higher absolute leucocyte values (10.3 versus 8.1 G/L; p = 0.02) as well as an elevated frequency of leucocytosis (64% versus 28%; p = 0.02) and elevated CRP (60% versus 28%; p = 0.04) in patients without a history of trauma ("spontaneous" CAD) compared with patients with trauma-related CAD. As the elevated inflammatory laboratory parameters were not associated with an elevated infection rate, these findings imply a role of an acute inflammation as a pathogenetic factor in spontaneous CAD. The cause and mechanism of the inflammatory process remain unknown.

Vertebral artery dissection in children: a comprehensive review.

Vertebral artery dissection (VAD) has been infrequently recognized in children. The authors have reviewed 68 reported cases of VAD in children in the existing literature. An association between routine types of neck movement in sports and the evolution of VAD was recognized in half of the reported cases. Boys outnumbered girls by a ratio of 6.6 to 1, in contrast to adults, for whom the male to female ratio is approximately equal (1.3 to 1). Neck pain, one of the hallmark symptoms of VAD in adults, was infrequently noted in this young population (12%). Most children presented with various combinations of symptoms and signs, including ataxia (53%), headache (38%) and vomiting (34%). Eye signs or symptoms were noted in 72% of patients, and paresis/paralysis of one or more extremity occurred in 54%. Angiography was the method most frequently used to diagnose VAD (63/68; 93%). Magnetic resonance angiography (MRA) revealed pathognomonic signs of VAD in only 3 out of 13 patients evaluated (23%). In this series of 68 patients, 48 reports failed to indicate whether or not a cervical X-ray was performed, but in the 20 patients for whom such information was recorded, half had skeletal abnormalities in the occipital/atlas/axis region. The most common treatments were antiplatelet therapy (n = 15) and anticoagulation with (n = 8) or without (n = 7) supplemental antiplatelet therapy. Asymptomatic recovery occurred in 12 of the 15 patients (80%) who received antiplatelet therapy compared with 4 of the 15 patients (27%) who received anticoagulation therapy with or without antiplatelet therapy. There is a very high incidence of associated cervical anomalies in children with VAD. Further studies are required to determine if noninvasive examinations such as magnetic resonance imaging, ultrasonography, computed tomography angiography and MRA could replace angiography as the modality of choice in establishing the diagnosis of VAD in children. The role of different therapies for children presenting with symptoms related to VAD is unclear.

Plasma homocysteine concentration, C677T MTHFR genotype, and 844ins68bp CBS genotype in young adults with spontaneous cervical artery dissection and atherothrombotic stroke.

BACKGROUND AND PURPOSE: The role of mild hyperhomocysteinemia as a risk factor for cerebral ischemia may depend on stroke subtype. To test this hypothesis, we undertook a prospective case-control study of a group of patients with spontaneous cervical artery dissection (sCAD), a group of patients with atherothrombotic stroke (non-CAD), and a group of control subjects. METHODS: Fasting total plasma homocysteine (tHcy) concentration, C677T MTHFR genotype, and 844ins68bp CBS genotype were determined in 25 patients with sCAD, 31 patients <45 years of age with non-CAD ischemic stroke, and 36 control subjects. Biochemical data in the patient groups were obtained within the first 72 hours of stroke onset. RESULTS: Median tHcy levels were significantly higher in patients with sCAD (13.2 micromol/L; range, 7 to 32.8 micromol/L) compared with control subjects (8.9 micromol/L; range, 5 to 17.3 micromol/L; 95% CI, 1.05 to 1.52; P=0.006). Cases with tHcy concentration above the cutoff level of 12 micromol/L were significantly more represented in the group of patients with sCAD compared with control subjects (64% versus 13.9%; 95% CI, 2.25 to 44.23; P=0.003); a significant association between the MTHFR TT genotype and sCAD was also observed (36% versus 11.1%; 95% CI, 1.10 to 19.23; P=0.045). No significant difference in tHcy levels and in the prevalence of thermolabile MTHFR was found between patients with non-CAD ischemic stroke and control subjects and between patients with sCAD and non-CAD ischemic stroke. The distribution of the 844ins68bp CBS genotype and the prevalence of subjects carrying both the TT MTHFR and 844ins68bp CBS genotypes were not significantly different among the 3 groups. CONCLUSIONS: Our results are consistent with the hypothesis that increased plasma homocysteine levels and the TT MTHFR genotype may represent risk factors for sCAD. In contrast, their role in atherothrombotic strokes remains a contentious issue.