Reclassifications of ischemic stroke patterns due to variants of the Circle of Willis.

BACKGROUND: Variants of the Circle of Willis (vCoW) may impede correct identification of ischemic lesion patterns and stroke etiology. We assessed reclassifications of ischemic lesion patterns due to vCoW. METHODS: We analyzed vCoW in patients with acute ischemic stroke from the 1000+ study using time-of-flight magnetic resonance angiography (TOF MRA) of intracranial arteries. We assessed A1 segment agenesis or hypoplasia in the anterior circulation and fetal posterior cerebral artery in the posterior circulation. Stroke patterns were classified as one or more-than-one territory stroke pattern. We examined associations between vCoW and stroke patterns and the frequency of reclassifications of stroke patterns due to vCoW. RESULTS: Of 1000 patients, 991 had evaluable magnetic resonance angiography. At least one vCoW was present in 37.1%. VCoW were more common in the posterior than in the anterior circulation (33.3% vs. 6.7%). Of 238 patients initially thought to have a more-than-one territory stroke pattern, 20 (8.4%) had to be reclassified to a one territory stroke pattern after considering vCoW. All these patients had fetal posterior cerebral artery and six (30%) additionally had carotid artery disease. Of 753 patients initially presumed to have a one-territory stroke pattern, four (0.5%) were reclassified as having more-than-one territory pattern. CONCLUSIONS: VCoW are present in about one in three stroke patients and more common in the posterior circulation. Reclassifications of stroke lesion patterns due to vCoW occurred predominantly in the posterior circulation with fetal posterior cerebral artery mimicking multiple territory stroke pattern. Considering vCoW in these cases may uncover symptomatic carotid disease.

Biomarkers in Vasculitides of the Nervous System.

Besides being affected by the rare and severe primary angiitis of the central nervous system (PACNS) the nervous system is also affected by primary systemic vasculitides (PSV). In contrast to PACNS, PSV affect not only the central but also the peripheral nervous system, resulting in a large array of potential symptoms. Given the high burden of disease, difficulties in distinguishing between differential diagnoses, and incomplete pathophysiological insights, there is an urgent need for additional precise diagnostic tools to enable an earlier diagnosis and initiation of effective treatments. Methods available to date, such as inflammatory markers, antibodies, cerebrospinal fluid (CSF) analysis, imaging, and biopsy, turn out to be insufficient to meet all current challenges. We highlight the use of biomarkers as an approach to extend current knowledge and, ultimately, improve patient management. Biomarkers are considered to be useful for disease diagnosis and monitoring, for predicting response to treatment, and for prognosis in clinical practice, as well as for establishing outcome parameters in clinical trials. In this article, we review the recent literature on biomarkers which have been applied in the context of different types of nervous system vasculitides including PACNS, giant-cell arteritis, Takayasu's arteritis, polyarteritis nodosa, ANCA (anti-neutrophil cytoplasm antibody)-associated vasculitides, cryoglobulinemic vasculitis, IgA vasculitis, and Behçet's disease. Overall, the majority of biomarkers is not specific for vasculitides of the nervous system.

Clinical significance of acute and chronic ischaemic lesions in multiple cerebral vascular territories.

OBJECTIVES: To investigate the association between acute and chronic ischaemic lesions in a multiple territory lesion pattern (MTLP) detected by 3-Tesla MRI and stroke aetiology, specifically atrial fibrillation-associated stroke. METHODS: We analysed data from the 1000+ study - a prospective, observational 3-Tesla MRI cohort study of consecutively included acute stroke patients. Acute and chronic lesions were detected by DWI and fluid-attenuated inversion recovery, respectively. Observers blinded to clinical data allocated lesions to the right anterior, left anterior or posterior circulation. Lesion pattern was categorised as MTLPa/c when more than one territory was affected by either acute or chronic lesions or as MTLPa when more than one territory was affected by acute lesions alone. RESULTS: Of the 1,000 included patients, an MTLPa/c was found in 43% and MTLPa in 24%. Advanced age (aOR=1.21 per 10 years, 95% CI 1.06-1.39), atrial fibrillation (aOR=1.44, 95% CI 1.06-1.94), aortic arch atherosclerosis (aOR=2.52, 95% CI 1.10-5.77), malignant disease (aOR=1.99, 95% CI 1.25-3.16) and lower estimated glomerular filtration rate (eGFR) (aOR=0.90 per 10 ml, 95% CI 0.84-0.97) were associated with MTLPa/c. Only malignant disease (aOR=2.03, 95% CI 1.27-3.23) and lower eGFR (aOR=0.91 per 10 ml, 95% CI 0.85-0.97) were associated with MTLPa. CONCLUSIONS: An MRI-detected multiple territory lesion pattern of acute and chronic ischaemic lesions is frequent and more often present in older patients and patients with atrial fibrillation, aortic arch atherosclerosis, malignant disease and lower eGFR. Considering not only acute but also chronic ischaemic lesions may facilitate identifying atrial fibrillation-associated or aorto-embolic stroke. KEY POINTS: • Brain imaging with MRI may help to determine the aetiology of stroke. • Of 1,000 stroke patients undergoing 3-Tesla MRI, 43% had acute and chronic ischaemic lesions in multiple cerebral vascular territories. • Atrial fibrillation, aortic arch atherosclerosis and malignant disease were associated with a multiple territory lesion pattern.