Meschia, James F.

Background: Migraine is associated with neuroimaging differences in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). However, it is unknown if migraine-related disability (MRD) or if calcitonin gene-related peptide (CGRP), a vasoactive peptide important in migraine pathology, have radiographic implications. The aims of this study were to identify whether MRD or interictal serum CGRP levels impacted neuroimaging findings for those with CADASIL. Materials and Methods: A cross-sectional analysis was performed. The primary outcomes were neuroimaging differences associated with MRD among those with migraine or interictal serum CGRP levels of those with and without migraine. MRD was defined by 2 migraine disability scales (Migraine Disability Assessment, Headache Impact Test-6). Retrospective brain magnetic resonance imaging was reviewed (average 1.7 ± 2.0 y before enrollment). Rank-sum and χ2 tests were used. Results: Those with migraine (n=25, vs. n=14 without) were younger [median 49 (25 to 82) y vs. 60 (31 to 82) y, P<0.007], had fewer cerebral microbleeds (0 to 31 vs. 0 to 50, P=0.02) and less frequently had anterior temporal lobe T2 hyperintensities [68% (17/25) vs 100% (14/14), P=0.02]. MRD scale outcomes had no significant radiographic associations. Interictal serum CGRP did not differ (migraine: n=18, 27.0±9.6 pg/mL vs. no migraine: n=10, 26.8±15.7 pg/mL, P=0.965). Conclusions: Migraine may forestall microangiopathy in CADASIL, though possibly independent of severity as measured by MRD. Interictal serum CGRP did not differ in our cohort suggesting CGRP may not be vital to migraine pathophysiology in CADASIL. Larger studies are needed to account for age differences.

Introduction: Cervical artery dissection (CAD) is a well-recognized cause of acute ischemic stroke, especially in young adults, accounting for up to 20-25% of all cases. Several studies reported an incidence between 2.5-5 per 100,000 in the general population. However, the actual incidence may be higher as many patients remain asymptomatic. Even though CAD is one of the leading causes of ischemic stroke, there is a lack of consensus in management. Our study surveyed practicing clinicians involved in the management of CAD to characterize current practice trends and provide a foundation for future research. Methods: An online case-based questionnaire with 11 questions regarding the management of cervical artery dissection was developed and piloted internally with 12 Mayo Clinic cerebrovascular neurologist/neurosurgeons. The survey was finalized, and initially sent to the STOP-CAD study group. We then sent the survey to practicing vascular neurologists across different academic institutions. Surveys were sent to 126 unique individuals. Results: A total of 42 clinicians completed the questionnaires. The response rate was 33% (42/126). Aspirin antiplatelet monotherapy was seen as the most appropriate therapy for asymptomatic CAD (81% [34/42]). Anticoagulation was the treatment of choice for cases with CAD and concomitant intraluminal thrombus (74% [31/42]). Most (74% [31/42]) of the participants recommended repeat imaging at three months. However, no consistent response regarding the type of antithrombotic agent for symptomatic CAD without intramural thrombus or cases with pseudoaneurysm. There was marked variability regarding the duration of antithrombotic therapy, ranging from three months to life-long treatment. Conclusion: Marked variability was seen in the management of CAD, especially regarding the choice of antithrombotic agent in symptomatic and complicated (stenosis or pseudoaneurysm) cases and the duration of such therapy, which reflects the lack of definitive clinical trial data. Ongoing research is needed to better guide the optimal management of these patients.

Introduction: Carotid revascularization is known to prevent stroke in patients with high-grade carotid stenosis, but whether carotid revascularization may slow the progression of hemispheric WMD in patients with carotid stenosis to prevent cognitive decline have not been well described. Methods: We conducted a longitudinal study involving patients age ≥40 years with carotid stenosis on ultrasound from 2011-2015 with serial brain MRI scans at least 1 year apart followed for radiographic and clinical outcomes to 2020. Severity of carotid stenosis was defined as moderate 50-69%, high-grade 70-99%, or occluded. Hemispheric WMD volume was quantified from axial T2 FLAIR images. Patients were stratified by revascularization status. Primary outcome was change in WMD volume per year ipsilateral or contralateral to the index carotid. Hemispheric differences in the annual rate of WMD progression (cc/yr) were compared between revascularized vs not revascularized using multivariable linear regression analysis adjusted for variables that differed between revascularization status. Results: Of the 150 patients, moderate stenosis was present in 37.3%, high-grade stenosis in 42.0%, and carotid occlusion in 20.7%. Mean age was 71±10 years, 36.7% were female. Seventy-three (48.7%) had carotid revascularization with a median follow-up of 5.1 years. Baseline WMD volume was 4.86cc ipsilateral and 4.39cc contralateral to the index carotid. Patients who underwent revascularization trended to have slower WMD progression in the hemisphere ipsilateral to the index carotid compared to those not revascularized (0.32cc/yr vs 0.63 cc/yr, p=0.340). The same trend was not observed in the contralateral hemisphere. In adjusted models, carotid revascularization was associated with a 0.33 cc per year decrease in WMD progression between hemispheres compared to those not revascularized (β= -0.33, p=0.070). Conclusions: In this study with a median follow-up of 5 years, we found that carotid revascularization resulted in a 50% reduction in the annual rate of WMD progression. Intervention trials should test whether carotid revascularization slows WMD progression in patients with cognitive impairment to prevent further cerebrovascular events and cognitive decline.

Introduction: Collateral circulation plays a crucial role in determining the extent of brain tissue ischemia and functional outcome in large vessel occlusive (LVO) stroke. Heart failure (HF) is known to cause cerebral hypoperfusion, yet the relationship between HF and robustness of collateral flow has not been well described. Here we hypothesized that HF is associated with poor collateral flow and functional outcome in patients presenting with LVO treated with mechanical thrombectomy (MT). Methods: A single center retrospective study of patients presenting with LVO ischemic stroke who underwent MT between 2012-2020 was done. Single-phase CTA of head prior to MT was used to assess collateral status with poor status defined as ≤ 50% filling and good status as >50% filling. Classification of HF by left ventricular ejection fraction (LVEF) on echocardiogram was used where HF with reduced ejection fraction (HFrEF) had LVEF ≤40%, HF with preserved EF (HFpEF) had LVEF ≥50% with evidence of structural heart disease, and no HF was LVEF≥50% without structural heart disease. Functional outcome was modified Rankin scale (mRS) at 90 days with scores of 0-2 representing good outcome and 3-6 representing poor outcome. Multivariable logistic regression analyses were performed to evaluate the association between HF and poor collaterals after adjusting for vascular risk factors. Results: We identified 235 patients, mean age was 69 ±15 years, median NIHSS was 18, and 45.5% had HF (HFrEF 12.8%, HFmrEF 4.7%, HFpEF 28.1%) while 54.5% had no HF. Poor collaterals were seen in 47.7%, and those with HF were likely to have poor collaterals compared to those without HF (56.1% vs 35.1%, P=.001). There was a dose-dependent relationship between severity of HF and poor collaterals: adjusted odds of poor collaterals were 1.63 and 2.45 in HFpEF and HFrEF, compared to those without HF (trend p=.018). Patients with poor collaterals were likely to have poor outcome at 3 months compared to those with good collaterals (75.0% vs 57.8%; p=.015). Conclusion: Patients with HFrEF were twice as likely to have poor collaterals. This study demonstrated a likely mechanism for poor outcomes seen in ischemic stroke with HF, future studies may explore whether optimization of HF may augment collaterals to improve outcomes.

Introduction: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic, progressive microangiopathy caused by mutations in the NOTCH3 gene. Patients often present with migraine and progressive subcortical infarcts resulting in vascular cognitive impairment and death. Currently, there are no disease modifying treatments. Limiting future trials is the lack of an objective construct to classify and monitor severity of disease. The purpose of this study was to gain experience with a novel CADASIL severity grading system. Methods: Neurologists at 5 academic centers retrospectively reviewed charts of those with confirmed CADASIL. Demographic and clinical data were recorded. The CADASIL severity grades were then assigned: 0 (asymptomatic), 1 (migraine alone), 2 (stroke or mild cognitive impairment), 3 (gait impairment or early dementia) and 4 (bedbound) based on available data. Standard descriptive statistical analyses were used. Results: We identified 138 patients; overall mean age of 50.9±13.1 years, 42.8% were men. 15 (10.9%) were grade 0, 50 (36.2%) were grade 1, 41 (44.2%) were grade 2, 12 (8.7%) were grade 3, and none were grade 4. Those with less severe disease tended to be younger, more likely men, had a lower rate of hypertension and diabetes mellitus and were less frequently tobacco users, Table 1. Increasing number of vascular risk factors was associated with higher severity grading. Conclusion: Our study highlights the ability of this severity scale to separate those with CADASIL into an ordinal system. As known in the literature, more advanced phenotypes of CADASIL tend to have more vascular risk factors. Future trials may consider utilizing this ordinal construct to monitor disease progression, response to therapy, or as a screening tool.

Abstract This study aimed to investigate the influence of stroke lesions in predefined highly interconnected (rich‐club) brain regions on functional outcome post‐stroke, determine their spatial specificity and explore the effects of biological sex on their relevance. We analyzed MRI data recorded at index stroke and ~3‐months modified Rankin Scale (mRS) data from patients with acute ischemic stroke enrolled in the multisite MRI‐GENIE study. Spatially normalized structural stroke lesions were parcellated into 108 atlas‐defined bilateral (sub)cortical brain regions. Unfavorable outcome (mRS > 2) was modeled in a Bayesian logistic regression framework. Effects of individual brain regions were captured as two compound effects for (i) six bilateral rich club and (ii) all further non‐rich club regions. In spatial specificity analyses, we randomized the split into “rich club” and “non‐rich club” regions and compared the effect of the actual rich club regions to the distribution of effects from 1000 combinations of six random regions. In sex‐specific analyses, we introduced an additional hierarchical level in our model structure to compare male and female‐specific rich club effects. A total of 822 patients (age: 64.7[15.0], 39% women) were analyzed. Rich club regions had substantial relevance in explaining unfavorable functional outcome (mean of posterior distribution: 0.08, area under the curve: 0.8). In particular, the rich club‐combination had a higher relevance than 98.4% of random constellations. Rich club regions were substantially more important in explaining long‐term outcome in women than in men. All in all, lesions in rich club regions were associated with increased odds of unfavorable outcome. These effects were spatially specific and more pronounced in women.