Transcranial Doppler cerebrovascular reactivity: Thresholds for clinical significance in cerebrovascular disease.

BACKGROUND AND PURPOSE: Thresholds for abnormal transcranial Doppler cerebrovascular reactivity (CVR) studies are poorly understood, especially for patients with cerebrovascular disease. Using a real-world cohort with cerebral arterial stenosis, we sought to describe a clinically significant threshold for carbon dioxide reactivity (CO2R) and vasomotor range (VMR). METHODS: CVR studies were performed during conditions of breathing room air normally, breathing 8% carbon dioxide air mixture, and hyperventilation. The mean and standard deviation (SD) of CO2R and VMR were calculated for the unaffected side in patients with unilateral stenosis; a deviation of 2 SDs below the mean was chosen as the threshold for abnormal. Receiver operating characteristic (ROC) curves for both sides for patients with unilateral and bilateral stenosis were evaluated for sensitivity (Sn) and specificity (Sp). RESULTS: A total of 133 consecutive CVR studies were performed on 62 patients with stenosis with mean±SD age 55±16 years. Comorbidities included hypertension (60%), diabetes (15%), stroke (40%), and smoking (35%). In patients with unilateral stenosis, mean±SD CO2R for the unaffected side was 1.86±0.53%, defining abnormal CO2R as <0.80%. Mean±SD CO2R for the affected side was 1.27±0.90%. The CO2R threshold predicted abnormal acetazolamide single-photon emission computed tomography (SPECT) (Sn = .73, Sp = .79), CT/MRI perfusion abnormality (Sn = .42, Sp = .77), infarction on MRI (Sn = .45, Sp = .76), and pressure-dependent exam (Sn = .50, Sp = .76). For the unaffected side, mean±SD VMR was 39.5±15.8%, defining abnormal VMR as <7.9%. For the affected side, mean±SD VMR was 26.5±17.8%. The VMR threshold predicted abnormal acetazolamide SPECT (Sn = .46, Sp = .94), infarction on MRI (Sn = .27, Sp = .94), and pressure-dependent exam (Sn = .31, Sp = .90). CONCLUSIONS: In patients with multiple vascular risk factors, a reasonable threshold for clinically significant abnormal CO2R is <0.80% and VMR is <7.9%. Noninvasive CVR may aid in diagnosing and risk stratifying patients with stenosis.

A systematic review on the assessment of cerebral autoregulation in patients with Large Vessel Occlusion.

As the majority of large vessel occlusion (LVO) patients are not treated with revascularization therapies or efficiently revascularized, complementary management strategies are needed. In this article we explore the importance of cerebral autoregulation (CA) assessment in the prediction and/or modification of infarct growth and hemorrhagic transformation. In patients with LVO, these are important factors that affect prognosis. A systematic search of the PubMed, EMBASE databases and a targeted Google search was conducted, resulting in the inclusion of 34 relevant articles. There is an agreement that CA is impaired in patients with LVO; several factors have been identified such as time course, revascularization status, laterality, disease subtype and location, some of which may be potentially modifiable and affect outcomes. The personalized CA assessment of these patients suggests potential for better understanding of the inter-individual variability. Further research is needed for the development of more accurate, noninvasive techniques for continuous monitoring and personalized thresholds for CA.

Stroke characteristics and outcomes in urban Tanzania: Data from the Prospective Lake Zone Stroke Registry.

BACKGROUND: Stroke is a second leading cause of death globally, with an estimated one in four adults suffering a stroke in their lifetime. We aimed to describe the clinical characteristics, quality of care, and outcomes in adults with stroke in urban Northwestern Tanzania. METHODS: We analyzed de-identified data from a prospective stroke registry from Bugando Medical Centre in Mwanza, the second largest city in Tanzania, between March 2020 and October 2022. This registry included all adults ⩾18 years admitted to our hospital who met the World Health Organization clinical definition of stroke. Information collected included demographics, risk factors, stroke severity using the National Institutes of Health Stroke Scale, brain imaging, indicators for quality of care, discharge modified Rankin Scale, and in-hospital mortality. We examined independent factors associated with mortality using logistic regression. RESULTS: The cohort included 566 adults, of which 52% (294) were female with a mean age of 65 ± 15 years. The majority had a first-ever stroke 88% (498). Premorbid hypertension was present in 86% (488) but only 41% (200) were taking antihypertensive medications before hospital admission; 6% (32) had HIV infection. Ischemic strokes accounted for 66% (371) but only 6% (22) arriving within 4.5 h of symptom onset. In-hospital mortality was 29% (127). Independent factors associated with mortality were severe stroke (adjusted odds ratio (aOR) = 1.81, 95% confidence interval (CI) = 1.47-2.24, p < 0.001), moderate to severe stroke (aOR = 1.49, 95% CI = 1.22-1.84, p < 0.001), moderate stroke (aOR = 1.80, 95% CI = 1.52-2.14, p < 0.001), leukocytosis (aOR = 1.19, 95% CI = 1.03-1.38, p = 0.022), lack of health insurance coverage (aOR = 1.15, 95% CI = 1.02-1.29, p = 0.025), and not receiving any form of venous thromboembolism prophylaxis (aOR = 1.18, 95% CI = 1.02-1.37, p = 0.027). CONCLUSION: We report a stroke cohort with poor in-hospital outcomes in urban Northwestern Tanzania. Early diagnosis and treatment of hypertension could prevent stroke in this region. More work is needed to raise awareness about stroke symptoms and to ensure that people with stroke receive guidelines-directed therapy.

Venous Sinus Stenting for Low Pressure Gradient Stenoses in Idiopathic Intracranial Hypertension.

BACKGROUND: Medically refractory idiopathic intracranial hypertension (IIH) is frequently treated with venous sinus stenosis stenting with high success rates. Patient selection has been driven almost exclusively by identification of supraphysiological venous pressure gradients across stenotic regions based on theoretical assessment of likelihood of response. OBJECTIVE: To explore the possibility of benefit in low venous pressure gradient patients. METHODS: Using a single-center, prospectively maintained registry of patients with IIH undergoing venous stenting, we defined treatment groups by gradient pressures of ≤4, 5 to 8, and >8 mmHg based on the most frequently previously published thresholds for stenting. Baseline demographics, clinical, and neuro-ophthalmological outcomes (including optical coherence tomography and Humphrey visual fields) were compared. RESULTS: Among 53 patients, the mean age was 32 years and 70% female with a mean body mass index was 36 kg/m 2 . Baseline characteristics were similar between groups. The mean change in lumbar puncture opening pressure at 6 months poststenting was similar between the 3 groups (≤4, 5-8, and >8 mmHg; 13.4, 12.9, and 12.4 cmH 2 O, P = .47). Papilledema improvement was observed across groups at 6 months (100, 93, and 86, P = .7) as were all clinical symptoms. The mean changes in optical coherence tomography retinal nerve fiber layer (-30, -54, and -104, P = .5) and mean deviation in Humphrey visual fields (60, 64, and 67, P = .5) at 6 weeks were not significantly different. CONCLUSION: Patients with IH with low venous pressure gradient venous sinus stenosis seem to benefit equally from venous stenting compared with their higher gradient counterparts. Re-evaluation of our restrictive criteria for this potentially vision sparing intervention is warranted. Future prospective confirmatory studies are needed.

Ischemic Stroke at a Tertiary Academic Hospital in Tanzania: A Prospective Cohort Study With a Focus on Presumed Large Vessel Occlusion.

Background: Large vessel ischemic strokes account for more than one-third of all strokes associated with substantial morbidity and mortality without early intervention. The incidence of large vessel occlusion (LVO) is not known in sub-Saharan Africa (SSA). Definitive vessel imaging is not routinely available in resource-limited settings. Aims: We aimed to investigate the burden and outcomes of presumed LVO among patients with ischemic stroke admitted to a large tertiary academic hospital in Tanzania. Methods: This cohort study recruited all consenting first-ever ischemic stroke participants admitted at a tertiary hospital in Tanzania. Demographic data were recorded, and participants were followed up to 1 year using the modified Rankin Scale (mRS). A diagnosis of presumed LVO was made by a diagnostic neuroradiologist and interventional neurologist based on contiguous ischemic changes in a pattern consistent with proximal LVO on a non-contrast computed tomography head. We examined factors associated with presumed LVO using logistic regression analysis. Inter-observer Kappa was calculated. Results: We enrolled 158 first-ever ischemic strokes over 8 months with a mean age of 59.7 years. Presumed LVO accounted for 39.2% [95% confidence interval (CI) 31.6-47.3%] and an overall meantime from the onset of stroke symptoms to hospital arrival was 1.74 days. Participants with presumed LVO were more likely to involve the middle cerebral artery (MCA) territory (70.9%), p < 0.0001. Independent factors on multivariate analysis associated with presumed LVO were hypertension [adjusted odds ratio (aOR) 5.74 (95% CI: 1.74-18.9)] and increased waist-hip ratio [aOR 7.20 (95% CI: 1.83-28.2)]. One-year mortality in presumed LVO was 80% when compared with 73.1% in participants without presumed LVO. The Cohen's Kappa inter-observer reliability between the diagnostic neuroradiologist and interventional neurologist was 0.847. Conclusion: There is a high burden of presumed LVO associated with high rates of 1-year morbidity and mortality at a tertiary academic hospital in Tanzania. Efforts are needed to confirm these findings with definitive vessel imaging, promoting cost-effective preventive strategies to reduce the burden of non-communicable diseases (NCDs), and a call for adopting endovascular therapies to reduce morbidity and mortality.

Temporal Trends in Racial and Ethnic Disparities in Endovascular Therapy in Acute Ischemic Stroke.

Introduction Endovascular therapy (EVT) use increased following clinical trials publication in 2015, but limited data suggest there may be persistent race and ethnicity differences. Methods and Results We included all patients with acute ischemic stroke arriving within 6 hours of last known well and with National Institute of Health Stroke Scale (NIHSS) score ≥6 between April 2012 and June 2019 in the Get With The Guidelines-Stroke database and evaluated the association between race and ethnicity and EVT use and outcomes, comparing the era before versus after 2015. Of 302 965 potentially eligible patients; 42 422 (14%) underwent EVT. Although EVT use increased over time in all racial and ethnic groups, Black patients had reduced odds of EVT use compared with non-Hispanic White (NHW) patients (adjusted odds ratio [aOR] before 2015, 0.68 [0.58‒0.78]; aOR after 2015, 0.83 [0.76‒0.90]). In-hospital mortality/discharge to hospice was less frequent in Black, Hispanic, and Asian patients compared with NHW. Conversely discharge home was more frequent in Hispanic (29.7%; aOR, 1.28 [1.16‒1.42]), Asian (28.2%; aOR, 1.23 [1.05‒1.44]), and Black (29.1%; aOR, 1.08 [1.00‒1.18]) patients compared with NHW (24%). However, at 3 months, functional independence (modified Rankin Scale, 0-2) occurred less frequently in Black (37.5%; aOR, 0.84 [0.75‒0.95]) and Asian (33%; aOR, 0.79 [0.65‒0.98]) patients compared with NHW patients (38.1%). Conclusions In a large cohort of patients treated with EVT, Black versus NHW patient disparities in EVT use have narrowed over time but still exist. Discharge related outcomes were slightly more favorable in racial and ethnic underrepresented groups; 3-month functional outcomes were worse but improved across all groups with time.

Predictors of 30-day mortality among patients with stroke admitted at a tertiary teaching hospital in Northwestern Tanzania: A prospective cohort study.

Background: Stroke is the second leading cause of death worldwide, with the highest mortality rates in low- to middle-income countries, particularly in sub-Saharan Africa. We aimed to investigate the predictors of 30-day mortality among patients with stroke admitted at a tertiary teaching hospital in Northwestern Tanzania. Methods: This cohort study recruited patients with the World Health Organization's clinical definition of stroke. Data were collected on baseline characteristics, the degree of neurological impairment at admission (measured using the National Institutes of Health Stroke Scale), imaging and electrocardiogram (ECG) findings, and post-stroke complications. The modified Rankin scale (mRS) was used to assess stroke outcomes. Kaplan-Meier analysis was used to describe survival, and the Cox proportional hazards model was used to examine predictors of mortality. Results: A total of 135 patients were enrolled, with a mean age of 64.5 years. Hypertension was observed in 76%, and 20% were on regular anti-hypertensive medications. The overall 30-day mortality rate was 37%. Comparing patients with hemorrhagic and ischemic stroke, 25% had died by day 5 [25th percentile survival time (in days): 5 (95% CI: 2-14)] versus day 23 [25th percentile survival time (in days): 23 (95% CI: 11-30) (log-rank p < 0.001)], respectively. Aspiration pneumonia was the most common medical complication, occurring in 41.3% of patients. ECG abnormalities were observed in 54.6 and 46.9% of patients with hemorrhagic and ischemic stroke, respectively. The most common patterns were as follows: ST changes 29.6 vs. 30.9%, T-wave inversion 34.1 vs. 38.3%, and U-waves 18.2 vs. 1.2% in hemorrhagic and ischemic stroke, respectively. Independent predictors for case mortality were as follows: mRS score at presentation (4-5) [aHR 5.50 (95% CI: 2.02-15.04)], aspiration pneumonia [aHR 3.69 (95% CI: 1.71-13.69)], ECG abnormalities [aHR 2.28 (95% CI: 1.86-5.86)], and baseline stroke severity [aHR 1.09 (95% CI: 1.02-1.17)]. Conclusion: Stroke is associated with a high 30-day mortality rate in Northwestern Tanzania. Concerted efforts are warranted in managing patients with stroke, with particular attention to individuals with severe strokes, ECG abnormalities, and swallowing difficulties to reduce early morbidity and mortality.

Disparities among neurointerventionalists suggest further investigation of conscious sedation versus general anesthesia during thrombectomy for acute stroke.

INTRODUCTION: Prior retrospective and case-control studies have shown that the use of general anesthesia (GA) during endovascular therapy (EVT) for acute ischemic stroke with large vessel occlusion (AIS-LVO) was independently associated with poor clinical outcomes compared with cases performed under conscious sedation (CS). Conversely, recent small randomized clinical trials (RCT) demonstrated a trend toward better outcome in cases performed under GA. METHODS: We submitted an online survey to 193 Society of Vascular Interventional Neurology and 78 American Association of Neurological Surgeons and Congress of Neurological Surgeons - Cerebrovascular Section neuroendovascular practitioners. Questions were aimed at understanding the current state of anesthesia practice during EVT, and to determine if there is clinical equipoise for a large multicenter RCT comparing GA versus CS during EVT. RESULTS: Between March and May of 2017, we received 116 (43%) responses. Anesthesiologists were responsible for managing 96% of the GA cases as compared to only 51% of the CS cases (P < 0.0001). Notable 56% of providers reported performing less than a quarter of their cases under GA. Only 7% performed all cases under GA compared with 17% who used solely CS (P = 0.048). More than half of respondents thought a new RCT was necessary, of whom 61% were interested in participating. Among interested responders, 59% were located in centers with 3 or more neurointerventionalists. CONCLUSION: The significant variation among neuroendovascular providers, added with the lack of consensus among recent trials and meta-analyses, demonstrate clinical equipoise for further studies to explore the effects of anesthesia during EVT in AIS-LVO.

Dual-center study comparing transradial and transfemoral approaches for flow diversion treatment of intracranial aneurysms.

BACKGROUND: The transfemoral approach (TFA) has been the traditional approach for neurointerventional cases. While the TFA allows for triaxial support in flow diverting stent cases, it is associated with access site complications. Recently, the transradial approach (TRA) has emerged as a safer alternative to the TFA. To the best of our knowledge, there have only been single-center studies comparing outcomes in flow diverter cases for these approaches. We demonstrate the safety and feasibility of the TRA for placement of flow diverting stents in the treatment of unruptured intracranial aneurysms at two high-volume centers. MATERIALS AND METHODS: We performed a retrospective review of prospectively collected institutional databases at two high-volume neuroendovascular centers. Cases from 2016 to 2018 of unruptured intracranial aneurysms treated by flow diverting stenting accessed through either the TRA or the TFA were compared. Patient demographics, procedural and radiographic metrics including location and size of the aneurysm, size, and length of the flow diverter implant, and fluoroscopic time were recorded. Puncture site complications and length of hospital stay were also included in the data analysis. RESULTS: There were three out of 29 TRA cases which were converted to the TFA. None of the TRA patients experienced site complications, whereas three TFA patients experienced site complications. While TRA and TFA patients did not differ significantly in their exposure to radiation, TRA patients experienced shorter hospital stays. CONCLUSIONS: While long-term studies are still lacking regarding this approach, we demonstrate that the TRA is a safe and feasible approach for flow diverter stent placement.

Dual Antiplatelet Therapy Duration After Venous Sinus Stenting for Idiopathic Intracranial Hypertension and Stent Survival-Is Longer Necessarily Better? A Meta-Regression.

BACKGROUND: Venous stenting (VS) for venous sinus stenosis in the setting of idiopathic intracranial hypertension has been increasing in acceptance by neurointerventionalists. Stent-adjacent stenosis (SAS) and in-stent stenosis leading to symptom recurrence and the need for retreatment are known delayed complications. However, the effect of the dual antiplatelet therapy (DAPT) duration on these complications has remained poorly characterized. METHODS: An extensive literature search was performed to identify reports of VS for patients with idiopathic intracranial hypertension from 2000 to 2020. The primary outcome was the occurrence of SAS. The secondary outcomes included the occurrence of composite stenosis (in-stent stenosis and SAS) and stent survival, defined as the need for retreatment or other surgical management. Generalized linear mixed models were used to explore the effects of DAPT duration (3 vs ≥6 months) on the primary and secondary outcomes. RESULTS: A total of 325 patients met the inclusion criteria and were included in our analysis. SAS occurred in 9% (95% confidence interval, 6%-15%) of the patients, and stent survival was 90% (95% confidence interval, 84%-93%) in the cohort. With every 1-mm Hg increase in the venous pressure gradient, an 8% decrease was found in the odds of stent survival (P = 0.043). The meta-regression revealed no association between the DAPT duration and the primary outcome or the odds of composite stenosis and stent survival. CONCLUSIONS: We found no differences between 3 and ≥6 months of DAPT in terms of the risk of stent stenosis or stent survival. However, patients with a higher venous pressure gradient before VS had a greater risk of stent failure.

Validation of diffuse correlation spectroscopy measures of critical closing pressure against transcranial Doppler ultrasound in stroke patients.

SIGNIFICANCE: Intracranial pressure (ICP), variability in perfusion, and resulting ischemia are leading causes of secondary brain injury in patients treated in the neurointensive care unit. Continuous, accurate monitoring of cerebral blood flow (CBF) and ICP guide intervention and ultimately reduce morbidity and mortality. Currently, only invasive tools are used to monitor patients at high risk for intracranial hypertension. AIM: Diffuse correlation spectroscopy (DCS), a noninvasive near-infrared optical technique, is emerging as a possible method for continuous monitoring of CBF and critical closing pressure (CrCP or zero-flow pressure), a parameter directly related to ICP. APPROACH: We optimized DCS hardware and algorithms for the quantification of CrCP. Toward its clinical translation, we validated the DCS estimates of cerebral blood flow index (CBFi) and CrCP in ischemic stroke patients with respect to simultaneously acquired transcranial Doppler ultrasound (TCD) cerebral blood flow velocity (CBFV) and CrCP. RESULTS: We found CrCP derived from DCS and TCD were highly linearly correlated (ipsilateral R2 = 0.77, p = 9 × 10 - 7; contralateral R2 = 0.83, p = 7 × 10 - 8). We found weaker correlations between CBFi and CBFV (ipsilateral R2 = 0.25, p = 0.03; contralateral R2 = 0.48, p = 1 × 10 - 3) probably due to the different vasculature measured. CONCLUSION: Our results suggest DCS is a valid alternative to TCD for continuous monitoring of CrCP.

Exception from informed consent in the era of social media: The SEGA stroke trial experience.

INTRODUCTION: Patients with acute ischemic stroke (AIS) and neurologic deficits are often unable to provide consent and excluded from emergency research participation. Experiences with exception from informed consent (EFIC) to facilitate research on potentially life-saving emergency interventions are limited. Here, we describe our multifaceted approach to EFIC approval for an ongoing randomized clinical trial that compares sedation versus general anesthesia (SEGA) approaches for endovascular thrombectomy during AIS. METHODS: We published a university clinical trial website with EFIC information. We initiated a social media campaign on Facebook within a 50 mile radius of Texas Medical Center. Advertisements were linked to our website, and a press release was issued with information about the trial. In-person community consultations were performed, and voluntary survey information was collected. RESULTS: A total of 193 individuals (65% female, age 46.7 ± 16.6 years) participated in seven focus group community consultations. Of the 144 (75%) that completed surveys, 88.7% agreed that they would be willing to have themselves or family enrolled in this trial under EFIC. Facebook advertisements had 134,481 (52% females; 60% ≥45 years old) views followed by 1,630 clicks to learn more. The website had 1130 views (56% regional and 44% national) with an average of 3.85 min spent. Our Institutional Review Board received zero e-mails requesting additional information or to optout. CONCLUSION: Our social media campaign and community consultation methods provide a significant outreach to potential stroke patients. We hope that our experience will inform and help future efforts for trials seeking EFIC.

Use of single versus multiple vasodilator agents in the treatment of cerebral vasospasm: is more better than less?

BACKGROUND: Patients with cerebral vasospasm caused by aneurysmal subarachnoid hemorrhage (aSAH) are often treated with intra-arterial (IA) vasodilator infusion. However, the optimal drug regimen is yet to be elucidated. METHODS: A retrospective review of patients with aSAH and cerebral vasospasm treated with IA vasodilator infusion was performed. Patients in group 1 (2008-2011) were treated with a single agent, either nicardipine or verapamil, and patients in group 2 (2010-2016) were treated with a regimen of nitroglycerin, verapamil, and nicardipine. The post-infusion improvement ratio (PIIR) was compared between groups. Adjusted multivariate logistic regression models were utilized to determine whether patients treated with multiple vasodilators had an improved functional outcome, defined by the modified Rankin Scale, at discharge and 90-day follow-up. RESULTS: Among 116 patients from group 1 (N = 47) and group 2 (N = 69), the median age was 54.5 years [IQR, 46-53 years] and 78% were female. Use of multiple-agent therapy resulted in a 24.36% improvement in vessel diameter over single-agent therapy (median PIIR: group 1, 10.5% [IQR, 5.3-21.1%] vs group 2, 34.9% [IQR, 21.4-66.0%]; p < 0.0001). In the adjusted multivariate logistic regression, the use of multiple-agent therapy was associated with a better functional outcome at discharge (OR 0.15, 95% CI [0.04-0.55]; p < 0.01) and at 90-day follow-up (OR 0.20, 95% CI [0.05-0.77]; p < 0.05) when compared to single-agent therapy. CONCLUSION: In this study, we found that patients treated for cerebral vasospasm with IA infusion of multiple vasodilators had an increased vessel response and better functional outcomes compared to those treated with a single agent.

Dynamic Cerebral Autoregulation Post Endovascular Thrombectomy in Acute Ischemic Stroke.

The development of the endovascular thrombectomy (EVT) technique has revolutionized acute stroke management for patients with large vessel occlusions (LVOs). The impact of successful recanalization using an EVT on autoregulatory profiles is unknown. A more complete understanding of cerebral autoregulation in the context of EVT may assist with post-procedure hemodynamic optimization to prevent complications. We examined cerebral autoregulation in 107 patients with an LVO in the anterior circulation (proximal middle cerebral artery (M1/2) and internal cerebral artery (ICA) terminus) who had been treated using an EVT. Dynamic cerebral autoregulation was assessed at multiple time points, ranging from less than 24 hours to 5 days following last seen well (LSW) time, using transcranial Doppler ultrasound recordings and transfer function analysis. Complete (Thrombolysis in Cerebral Infarction (TICI) 3) recanalization was associated with a more favorable autoregulation profile compared with TICI 2b or poorer recanalization (p < 0.05), which is an effect that was present after accounting for differences in the infarct volumes. Less effective autoregulation in the first 24 h following the LSW time was associated with increased rates of parenchymal hematoma types 1 and 2 hemorrhagic transformations (PH1-PH2). These data suggest that patients with incomplete recanalization and poor autoregulation (especially within the first 24 h post-LSW time) may warrant closer blood pressure monitoring and control in the first few days post ictus.

Microembolic Signals Detected by Transcranial Doppler Predict Future Stroke and Poor Outcomes.

BACKGROUND AND PURPOSE: Although transcranial Doppler detects microembolic signals (MES) in numerous settings, the practical significance of such findings remains unclear. METHODS: Clinical information from ischemic stroke or transient ischemic attack patients (n = 248) who underwent embolic monitoring from January 2015 to December 2018 was obtained. RESULTS: MES were found in 15% of studies and ischemic recurrence was seen in 11% of patients (over 7 ± 6 days). Patients with MES had more lacunes than those without MES (1 ± 3 vs. 1 ± 2, P = .016), were more likely to have ischemic recurrence (37% vs. 6%, P < .001), undergo a future revascularization procedure (26% vs. 10%, P = .005), have a longer length of stay (9 vs. 4 days, P = .043), and have worse functional disability at discharge (modified Rankin Scale 3-6, 66% vs. 34%, P < .001). After controlling for several relevant cofactors, patients with MES were more likely to have ischemic recurrence (HR 4.90, 95% CI 2.16-11.09, P < .001), worse functional disability (OR 3.31, 95% CI 1.22-8.99, P = .019), and longer length of stays (ß = .202, P < .001). CONCLUSIONS: MES may help to risk stratify patients as their presence is associated with ischemic recurrence and worse outcomes.

Embolization of carotid-cavernous fistulas: A technical note on simultaneous balloon protection of the internal carotid artery.

A carotid-cavernous fistula (CCF) is an abnormal connection between the carotid circulation and the cavernous sinus. Treatment of CCFs often consists of obliteration of the fistula by a transarterial or transvenous endovascular approach using embolic agents. However, fistula embolization is often halted due to the potential embolic complications that may arise from the retrograde flow of the embolic agents into the arterial circulation, which often leads to the development of fistula recurrence. Moreover, retreatment of a CCF recurrence is challenging and more complex approaches may be required. In this technical note, we describe our experience with CCF embolization in 25 patients treated at a single center. We utilized a transvenous approach for CCF embolization with simultaneous balloon occlusion of the internal carotid artery during the infusion of the embolic material into the fistula. In our series, this simultaneous protection of the internal carotid artery showed to be a safe technique to prevent embolic complications and to achieve successful obliteration of the fistula. On follow-up, 2 cases presented a recurrence, one due to technical difficulties and the other related to an undetected vascular injury. In conclusion, this technique provides a safe approach in the treatment of CCFs by decreasing the risk of embolic complications and increasing the effectiveness of the embolic agents in accomplishing the obliteration of the CCF.

De novo thalamic arteriovenous malformation in a boy with a brainstem cavernous malformation.

Brain arteriovenous malformations (bAVMs) have long been considered to be congenital, developing between the third and eighth weeks of embryogenesis. However, cases reporting their de novo formation suggest that these lesions can develop after birth and have challenged this concept. We present a case of a 6-year-old boy with a history of a brainstem cavernous malformation diagnosed after birth who later developed a de novo bAVM. The de novo occurrence of this bAVM distant to the site of the cavernous malformation and a prior negative catheter angiography contributes to the uncertainty of the dynamics and pathophysiology of bAVMs.

Microemboli After Successful Thrombectomy Do Not Affect Outcome but Predict New Embolic Events.

Background and Purpose- We aimed to determine if microemboli after endovascular thrombectomy correlate with unfavorable outcomes despite successful recanalization. Methods- This is a prospective multicenter study of consecutive patients with ischemic stroke and occlusion of anterior circulation vessels (terminal internal carotid or main trunk of the middle cerebral artery/first-order branch of the main trunk of the middle cerebral artery segments of middle cerebral artery) after successful thrombectomy (modified Treatment In Cerebral Ischemia grades 2b-3). Microembolic signals (MES) were assessed by 30 minutes of transcranial Doppler monitoring within 72 hours of the last-seen-well time. Major outcomes included modified Rankin Scale at 90 days and infarct volume on head computed tomography at 24 hours. We also assessed early outcomes based on National Institutes of Health Stroke Scale variation and recurrence of stroke, transient ischemic attack, or systemic embolism within 90 days. Results- Among 111 patients, MES were detected in 43 (39%), with a median rate of 4 counts/h (interquartile range 2-12). The occurrence of MES was not associated with a significant difference in modified Rankin Scale (ordinal shift analysis, adjusted odds ratio, 1.06 [95% CI, 0.48-2.34] P=0.85) nor in functional independence (modified Rankin Scale, 0-2: adjusted odds ratio, 0.52 [95% CI, 0.19-1.39] P=0.19). Patients with and without MES had similar infarct volumes (adjusted beta, 11.2 [95% CI, -46.6 to +22.9] P=0.51) on 24-hour computed tomography. MES did predict new embolic events (adjusted Cox hazard ratio, 6.78 [95% CI, 1.63-27.8] P=0.01). Conclusions- MES detected by transcranial Doppler following endovascular treatment of anterior circulation occlusions do not predict clinical or radiological outcome. However, such emboli are an independent marker of recurrent embolic events within 90 days.