Ronit Agid

Background: The Alberta Stroke Program Early CT Score (ASPECTS) and CT angiography (CTA) Collateral Score (CS) are routinely used to estimate ischemic core burden and collateral status in acute ischemic stroke due to large vessel occlusion, but suffer from limited reliability. Whether automated CT perfusion (CTP) maps improve scoring consistency remains unclear. Objectives: To assess the reliability of these scores on non-contrast computed tomography (NCCT) and CTA among numerous raters, with and without access to automated perfusion maps, and their correlations with endovascular thrombectomy (EVT) decisions. Methods: Twenty-nine clinicians independently rated 60 imaging cases from 30 late-window stroke patients with large vessel occlusion, each presented twice: once using NCCT and CTA alone (‘non-CTP cases’), and once with the addition of perfusion maps (‘CTP cases’). Twenty-eight raters (97%) completed the survey twice. Inter- and intra-reliability was assessed using Gwet’s AC1/2 coefficients (κ _G ). Correlations with EVT decisions were evaluated using Cramer V. Results: Inter-rater reliability for ASPECTS was substantial and similar between non-CTP (κ _G = 0.65, 95% CI: 0.53 to 0.78) and CTP cases (κ _G = 0.64, 95% CI: 0.51 to 0.77). CS showed an almost perfect reliability in both scenarios (κ _G = 0.82 and 0.83). Intra-rater agreement was at least substantial. Dichotomizing ASPECTS as 0-2/3-10 improved reliability to almost perfect. ASPECTS strongly correlated with EVT decisions (V=0.80), whereas CS showed moderate correlation (V=0.56), both remaining similar with the addition of CTP (V=0.75 and 0.54, respectively). Conclusion: Automated perfusion imaging did not improve the reliability of ASPECTS or CS. Strong reliability was achieved with NCCT and CTA alone.

Objective: Carotid web can serve as a nidus for clot formation and subsequent thromboembolic stroke. Although treatment historically involved antiplatelet therapy, recent evidence demonstrates notably elevated recurrent stroke rates despite best medical therapy. We examined the safety and efficacy of carotid artery stenting (CAS), which involves placing a coil in the artery, and carotid endarterectomy (CEA), a surgery to remove the clot, for treatment of symptomatic carotid web. Methods: A multi-institutional retrospective registry including adult patients with carotid web with history of ipsilateral acute ischemic stroke or transient ischemic attack (TIA) treated with either carotid artery stenting or endarterectomy was reviewed. Patient demographics, comorbidities, clinical presentation, treatment methodology, and outcomes at follow up were collected. Results: Among the 71 included patients (mean age 52.4 years, 44 (62.4%) female), 23 (32.4%) underwent CEA, and 48 (67.6%) underwent CAS. The most common presenting symptoms were hemibody numbness/weakness, aphasia, and gaze deviation. On average, patients had experienced 1.12 ± 0.7 strokes or TIAs before intervention, with a mean delay of 115 ± 224 days between initial stroke/TIA and intervention. The median preintervention modified Rankin Scale (mRS) score was 2. Perioperatively, one patient (1.41%) experienced stroke and none experienced myocardial infarction. During mean 14.8 (±29.2)-month follow up, one patient experienced asymptomatic recurrent stroke (1.41%). Median mRS at follow up was 1, and carotid artery stenting and endarterectomy demonstrated similar rates of postoperative complication and recurrent stroke rates. Conclusion: Our results suggest that endarterectomy and stenting are safe and efficacious for minimizing subsequent stroke risk in patients who have experienced stroke or TIA from carotid webbing, warranting further studies to determine the optimal timing and method of treatment.

BACKGROUND AND PURPOSE: Dural arteriovenous fistulas (DAVFs) exhibit varied clinical manifestations, and high-grade cases are associated with both a risk of hemorrhage and (in certain cases) dementia. Less known, however, is the association between DAVF and more subtle cognitive changes, which might not be clinically apparent without formal neurocognitive testing. This study prospectively assesses baseline cognitive changes in patients with unruptured DAVFs and looks at the effects of treatment on any such changes. MATERIALS AND METHODS: A longitudinal prospective study was conducted to formally evaluate the neurocognitive status of patients with unruptured DAVFs undergoing embolization. Pre- and posttreatment assessments included neurologic examinations and cognitive tests (Repeatable Battery for the Assessment of Neuropsychological Status and Trail-Making Test [TMT]). RESULTS: A total of 23 patients were treated, with 78% demonstrating cortical venous reflux at baseline. At baseline, 50% of patients demonstrated cognitive impairment in at least 1 cognitive domain, and this was significantly associated with cortical venous reflux (P < .05). Following treatment, significant improvements were observed in several cognitive domains. The mean change in Immediate Memory was an increase of 10.5 points (95% CI, 6.2–14.8, P < .001). Visuospatial/Constructional abilities showed a mean increase of 3.8 points (95% CI, 1.1–6.5, P = .008), while Language improved by a mean of 4.2 points (95% CI, 0.9–7.5, P = .015). Attention scores increased by a mean of 6.1 points (95% CI, 2.7–9.5, P < .001). Delayed Memory demonstrated a mean improvement of 7.4 points (95% CI, 3.5–11.3, P < .001), and the Total Repeatable Battery for the Assessment of Neuropsychological Status Score increased by a mean of 8.6 points (95% CI, 5.0–12.2, P < .001). For the TMT, the mean change in TMT-A was a decrease of 9.2 seconds (95% CI, 5.6–12.8, P < .001), indicating faster completion times. TMT-B scores decreased by a mean of 12.7 seconds (95% CI, 8.4–17.0, P < .001). The TMT B-A difference decreased by a mean of 3.5 seconds (95% CI, 0.5–6.5, P = .023), and the TMT B/A ratio showed a mean decrease of 0.18 (95% CI, 0.10–0.26, P = .002). Overall, among the patients with baseline cognitive impairment, 70% showed significant cognitive improvement following endovascular treatment, particularly in memory domains. CONCLUSIONS: In our study, 50% of patients with DAVFs had cognitive impairment when assessed with formal neurocognitive testing, with a significant link to cortical venous reflux. This cognitive impairment improved in 70% of those patients following treatment. These findings expand our understanding of how DAVF affects the brain, highlighting cognitive impairment as a critical factor. Consequently, the treatment of DAVFs should perhaps not only focus on hemorrhagic risk but also consider cognitive outcomes as a potential indicator for intervention.

Introduction: Posterior cerebral artery (PCA) aneurysms represent up to 1% of all cerebral aneurysms. P1-P2 perforator aneurysms are thought to be even less prevalent and often require complex treatment strategies due to their anatomical and morphological characteristics, with risk of a perforator infarct. We studied the treatment of P1-P2 perforator aneurysms in a single-center cohort from a high-volume tertiary center, reporting clinical and anatomical characteristics, treatment strategies, and outcomes. Methods: A retrospective analysis of adult patients with a P1-P2 perforator aneurysm who presented at our institution between January 2000 and January 2023 was performed. The patients were analyzed for demographics, clinical presentation, imaging findings, treatment techniques, outcomes, and complications. Subgroup analyses between ruptured versus non-ruptured cases were included. Results: Out of 2733 patients with a cerebral aneurysm, 14 patients (0.5%) presented with a P1-P2 perforator aneurysm. All six patients with a ruptured aneurysm were treated by endovascular coiling, of whom one patient (16.7%) required surgical clipping of a recurrence. One out of eight (12.5%) patients with unruptured aneurysms was treated by surgical clipping. P1-P2 perforator aneurysms predominantly affected middle-aged individuals (median 59.5 years), with 10/14 (71.4%) being female. Endovascular coiling was the primary treatment modality overall, yielding favorable technical outcomes, however, it was complicated by a perforator infarct in two patients (33.3%) without new permanent morbidity or mortality secondary to treatment. Conclusions: P1-P2 perforator aneurysms are a rare subtype of intracranial aneurysm. Endovascular coiling could present an effective treatment modality; however, care should be taken for ischemic complications in the dependent perforator territory. Larger studies are required to provide more insights.

Background: Limited research exists regarding the impact of neuroimaging modality on endovascular thrombectomy (EVT) decisions for late window large vessel occlusion (LVO) stroke cases. Purpose: This study assesses whether perfusion CT imaging: 1) alters the proportion of recommendations for EVT, and 2) enhances the reliability of EVT decision-making compared to non-contrast CT and CT angiography. Materials and Methods: We conducted an online survey using 30 patients drawn from an institutional database of 3144 acute stroke cranial CT scans. These cases were presented to 29 stroke or neurointerventional physicians from Canada across two sessions. Physicians evaluated each patient both with and without perfusion imaging and gave EVT recommendations. We used non-overlapping 95% confidence intervals and difference in agreement classification as criteria to suggest a difference between the Gwet AC1 statistics (κ _G ). Our outcomes were: 1) the proportion of EVT recommendations, and 2) interrater and intrarater agreement, with or without perfusion imaging. Results: In the first round, 29 raters completed the assessment, with 28 finishing the second round. The percentage of EVT recommendations differed by 1.1% with or without perfusion imaging. However, individual decisions changed in 21.4% of cases, with 11.3% against EVT and 10.1% in favor. Interrater agreement (κG) among the 29 raters was similar between non-perfusion CT neuroimaging and perfusion CT neuroimaging (κG = 0.487; 95% CI 0.327, 0.647 and κG = 0.552; 95% CI 0.430, 0.675). The 95% CIs overlapped with moderate agreement in both. Intrarater agreement exhibited overlapping 95% CIs for all 28 raters. κG was either substantial or excellent (0.81-1) for 71.4% (20/28) of raters in both groups. Conclusion: The difference in EVT recommendations is minimal with either neuroimaing protocol. Regarding agreement we found that use of automated CT perfusion images does not significantly impact the reliability of EVT decisions for late window LVO patients.

BACKGROUND AND PURPOSE: Ticagrelor is a novel P2Y12 antagonist, and little is known about its efficacy and safety in the endovascular treatment of aneurysms. This study evaluated the efficacy and safety of ticagrelor versus clopidogrel for stent-assisted coiling or flow-diversion treatment in patients with unruptured cerebral aneurysms. MATERIALS AND METHODS: From November 2003 to February 2019, two hundred one patients (mean age, 57.5 years; 156 women) with 233 unruptured aneurysms underwent stent-assisted coiling or flow-diversion treatment. All patients received antiplatelet therapy of aspirin plus clopidogrel (clopidogrel group, 121 patients with 140 aneurysms) or aspirin plus ticagrelor (ticagrelor group, 80 patients with 93 aneurysms). The clinical and radiologic data in each group were retrospectively reviewed and compared. RESULTS: Two hundred thirty-six procedures were performed, including stent-assisted coiling (n = 101) and flow diversion (n = 135). At 90 days, the primary outcome—a composite of any stroke and death—occurred in 9.9% of the clopidogrel group and 8.6% of the ticagrelor group (P = .822). Ischemic stroke occurred in 10 (7.0%) of the clopidogrel group and 7 (7.5%) of the ticagrelor group (P > .999). Disabling stroke occurred in 4 (2.8%) in the clopidogrel group and in 4 (4.3%) in the ticagrelor group (P = .716). Ninety-day death occurred in 3 (2.1%) in the clopidogrel group and 1 (1.1%) in the ticagrelor group (P > .999). Any bleeding at 90 days occurred in 13 (9.2%) in the clopidogrel group and 6 (6.5%) in the ticagrelor group (P = .479). CONCLUSIONS: Ticagrelor appears to be as effective and safe as clopidogrel in stent-assisted coiling or flow-diversion treatment for unruptured cerebral aneurysms.

Background: Delivery of most flow diverters (FD) requires larger, and thus stiffer microcatheters (0.021–0.027in.) which can pose challenges to intracranial navigation. The concomitant use of two microwires within one microcatheter, also known as the buddy-wire technique, may be helpful for navigation and support in challenging situations. Methods: We analyzed all flow diverter procedures in our prospectively collected database. We recorded all patient-related, anatomical and procedural information. We performed univariate statistics and technical descriptions. Results: In total, 208 consecutive patients treated with a FD at our institution between July 2014 and August 2020 were retrospectively analyzed. In 17 patients the buddy-wire technique was used (mean age 63 years, range 31–87 years: 16 female). Aneurysms were located at the petrous, cavernous, supraophthalmic internal carotid artery, and a proximal M2 branch in 2, 7, 7 and 1 patient(s), respectively. In all cases a 0.027in. microcatheter was used for device deployment. In 14 patients with a wide-necked aneurysm the buddy-wire provided additional support to advance the microcatheter and mitigated the ledge between the aneurysm neck and the parent artery or a side branch. In two giant cavernous aneurysms treated with telescoping FDs, the buddy-wire was used to re-enter the proximal end of the foreshortened FD. Conclusion: The buddy-wire is a useful technique in FD procedures to prevent herniation of the microcatheter into the aneurysm sack, in wide-necked aneurysms to mitigate the ledge effect between the aneurysm neck and the parent artery where the microcatheter tip may get stuck, or to enable re-entry into a foreshortened FD.

BACKGROUND AND PURPOSE: A number of studies have demonstrated the existence of segmental vascular disorders affecting soft tissues of the head and neck along with the intracranial vasculature. The purpose of this study was to determine whether there is an association between cerebral developmental venous anomalies and venous malformations of the face, head, and neck. MATERIALS AND METHODS: A consecutive series of patients with head and neck venous malformations who underwent MR imaging of the brain with postcontrast T1- or T2*-weighted imaging were included. Developmental venous anomaly prevalence in this patient population was compared with an age- and sex-matched control group without venous malformations at a ratio of 1:2. All images were interpreted by 2 neuroradiologists. Data were collected on venous malformation location, developmental venous anomaly location, developmental venous anomaly drainage pattern, and metameric location of venous malformations and developmental venous anomalies. Categoric variables were compared using χ² tests. RESULTS: Forty-two patients with venous malformations were included. The mean age was 38.1 ± 11.1 years, and 78.6% of patients were female. The prevalence of developmental venous anomalies in this patient population was 28.6%. The control population of 84 patients had a mean age of 40.0 ± 5.9 years, and 78.6% of patients were female. The prevalence of developmental venous anomalies in this patient population was 9.5% (P = .01). In 83.3% of cases, developmental venous anomalies were ipsilateral to the venous malformation, and in 75% of cases, they involved the same metamere. CONCLUSIONS: Our case-control study demonstrated a significant association between brain developmental venous anomalies and superficial venous malformations. These findings suggest that there may be a similar pathophysiologic origin for these 2 entities.