Anatomical characteristics of the styloid process in internal carotid artery dissection: Case-control study.

Introduction Pathophysiology of cervical artery dissection is complex and poorly understood. In addition to well-known causative and predisposing factors, including major trauma and monogenic connective tissue disorders, morphological characteristics of the styloid process have been recently recognized as a possible risk factor for cervical internal carotid artery dissection. Aims To study the association of the anatomical characteristics of styloid process with internal carotid artery dissection. Methods Retrospective, multicenter, case-control study of patients with internal carotid artery dissection and age- and sex-matched controls. Consecutive patients with internal carotid artery dissection and controls with ischemic stroke or transient ischemic attack of any etiology excluding internal carotid artery dissection, who had performed computed tomography angiography, diagnosed between January 2010 and September 2016. Two independent observers measured styloid process length and styloid process distance to internal carotid artery. Results Sixty-two patients with internal carotid artery dissection and 70 controls were included. Interobserver agreement was good for styloid process length and styloid process-internal carotid artery distance (interclass correlation coefficient = 0.89 and 0.76, respectively). Styloid process ipsilateral to dissection was longer than left and right styloid process in controls (35.8 ± 14.4 mm versus 30.4 ± 8.9 mm and 30.3 ± 8.2 mm, p = 0.011 and p = 0.008, respectively). Styloid process-internal carotid artery distance ipsilateral to dissection was shorter than left and right distance in controls (6.3 ± 1.9 mm versus 7.2 ± 2.1 mm and 7.0 ± 2.3 mm, p = 0.003 and p = 0.026, respectively). Internal carotid artery dissection was associated with styloid process length (odds ratio = 1.04 mm-1, 95% confidence interval = 1.01-1.08, p = 0.015) and styloid process-internal carotid artery distance (OR = 0.77 mm-1, 95% confidence interval = 0.64-0.92, p = 0.004). Conclusion Longer styloid process and shorter distance between styloid process and cervical internal carotid artery are associated with cervical internal carotid artery dissection.

Cerebrovascular Dissemination in Time and Space as a Predictor of Cardioembolism.

BACKGROUND: Cardioembolism has tendency to recur and cause lesions in distinct cerebrovascular territories. Using the imaging characteristics of cerebral lesions to determine dissemination in time and space (DTS) is a concept already used in other neurologic conditions; however, it has never been applied as a diagnostic tool in ischemic stroke etiology. AIM: This study aimed to assess DTS as a diagnostic marker of cardioembolism. METHODS: We enrolled consecutive patients with acute ischemic stroke of various etiologies admitted in a cerebrovascular disease nursery from a university hospital in a retrospective cohort study. We excluded patients with coexisting etiologies, incomplete study, or without an acute vascular lesion on computed tomography scan. Lacunar infarctions were not considered. Cerebrovascular territory was divided into right anterior, left anterior, and posterior. Localization of the acute vascular lesion(s), existence of previous vascular lesions, and their respective areas were analyzed. The presence of dissemination in time, space, or DTS was determined. RESULTS: We included 661 patients (mean age: 74.05 years (SD: 13.01)). Cardioembolism was the etiology with most DTS (30.47% of cardioembolic strokes); DT occurred more frequently within the atherosclerotic subtype (9.88%); DS was more prevalent within the arterial dissection group (3.33%). There was a statistically significant difference in stroke etiology between patients with DTS and patients without dissemination (P < .001). DTS had 81.67% specificity, 30.47% sensitivity, 66.67% positive predictive value, and 49.40% negative predictive value for the identification of cardioembolism. CONCLUSION: DTS is a specific diagnostic predictor of cardioembolic stroke and may be helpful in guiding etiologic investigation.