Detection and Quantification of Symptomatic Atherosclerotic Plaques With High-Resolution Imaging in Cryptogenic Stroke

BACKGROUND AND PURPOSE

High-resolution vessel wall imaging (HR-VWI) is a powerful tool in diagnosing intracranial vasculopathies not detected on routine imaging. We hypothesized that 7T HR-VWI may detect the presence of atherosclerotic plaques in patients with intracranial atherosclerosis disease initially misdiagnosed as cryptogenic strokes.

METHODS

Patients diagnosed as cryptogenic stroke but suspected of having an intracranial arteriopathy by routine imaging were prospectively imaged with HR-VWI. If intracranial atherosclerotic plaques were identified, they were classified as culprit or nonculprit based on the likelihood of causing the index stroke. Plaque characteristics, such as contrast enhancement, degree of stenosis, and morphology, were analyzed. Contrast enhancement was determined objectively after normalization with the pituitary stalk. A cutoff value for plaque-to-pituitary stalk contrast enhancement ratio (CR) was determined for optimal prediction of the presence of a culprit plaque. A revised stroke cause was adjudicated based on clinical and HR-VWI findings.

RESULTS

A total of 344 cryptogenic strokes were analyzed, and 38 eligible patients were imaged with 7T HR-VWI. Intracranial atherosclerosis disease was adjudicated as the final stroke cause in 25 patients. A total of 153 intracranial plaques in 374 arterial segments were identified. Culprit plaques (n=36) had higher CR and had concentric morphology when compared with nonculprit plaques (P≤0.001). CR ≥53 had 78% sensitivity for detecting culprit plaques and a 90% negative predictive value. CR ≥53 (P=0.008), stenosis ≥50% (P<0.001), and concentric morphology (P=0.030) were independent predictors of culprit plaques.

CONCLUSIONS

7T HR-VWI allows identification of underlying intracranial atherosclerosis disease in a subset of stroke patients with suspected underlying vasculopathy but otherwise classified as cryptogenic. Plaque analysis in this population demonstrated that culprit plaques had more contrast enhancement (CR ≥53), caused a higher degree of stenosis, and had a concentric morphology.

Food allergies are associated with increased disease activity in multiple sclerosis

OBJECTIVE

The association between allergy and multiple sclerosis (MS) is still unclear. In our study, we assessed the association between a self-reported history of allergic conditions with MS clinical and MRI disease activity.

METHODS

A subset of 1349 patients enrolled in the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women's Hospital (CLIMB) study completed a self-administered questionnaire on environmental, food and drug allergies. Patients were distributed among four allergy groups: (1) environmental, (2) food, (3) drug, (4) no known allergies (NKA). Clinical (number of attacks, expanded disability status scale (EDSS), MS severity score (MSSS)) and radiological variables (presence of gadolinium-enhancing lesions and lesion count), and their associations with the different allergy groups or those with NKA, were assessed.

RESULTS

The food allergy group had a 1.38 times higher rate for cumulative number of attacks compared with the NKA group (P=0.0062); this difference remained significant in the adjusted analysis (relapse rate ratio 1.27, P=0.0305). The food allergy group showed more than twice the likelihood (OR 2.53, P=0.0096) of having gadolinium-enhancing lesions on MRI. The environmental and drug allergy groups did not show significant differences when compared with the NKA group. The EDSS and MSSS were not affected by any type of allergy.

CONCLUSIONS

MS patients with food allergy had more relapses and a higher likelihood of gadolinium-enhancing lesions compared with patients with no known allergy. Future prospective studies are needed to confirm our findings and investigate underlying biological mechanisms, which may unveil new therapeutic and preventative strategies for MS.

Combined Transradial and Transfemoral Approach With Ostial Vertebral Balloon Protection for the Treatment of Patients With Subclavian Steal Syndrome

Background: Patients with an obstructive subclavian artery (SA) may exhibit symptoms of vertebrobasilar insufficiency known as subclavian steal syndrome (SSS). Endovascular treatment with stent assisted percutaneous transluminal angioplasty (SAPTA) demonstrates significantly lower percentage of intraoperative and postoperative complications in comparison with open surgery. There is a 1–5% risk of distal intracranial embolization through the ipsilateral vertebral artery (VA) during SAPTA.

Objective: To assess the safety and feasibility of a novel technique for distal embolic protection using balloon catheters during SA revascularization with a dual transfemoral and transradial access.

Methods: We describe a case series of patients with SSS who underwent SAPTA due to severe stenosis or occlusion of the SA using a combined anterograde/retrograde approach. Transfemoral access to SA was obtained using large bore guide sheaths. Ipsilateral transradial access was obtained using intermediate bore catheters. A Scepter XC balloon catheter was introduced through the transradial intermediate catheter into the ipsilateral VA at the ostium during SAPTA for distal embolic protection.

Results: A total of eight patients with SSS underwent subclavian SAPTA. Four patients had the combined anterograde/retrograde approach. Successful revascularization was achieved in three of them. It was difficult to create a channel in the fourth unsuccessful case due to heavily calcified plaque burden. No peri-operative ischemic events were identified. On follow-up, we demonstrated patency of the stents with resolution of symptoms and without any adverse events.

Conclusion: Subclavian stenting using a combined transradial and transfemoral access with compliant balloon catheters at the vertebral ostium for prevention of distal emboli may represent an alternative therapeutic approach for the treatment of SA stenosis and occlusions.

3D Enhancement Color Maps in the Characterization of Intracranial Atherosclerotic Plaques

BACKGROUND AND PURPOSE

High-resolution MR imaging allows the identification of culprit symptomatic plaques after the administration of gadolinium. Current high-resolution MR imaging methods are limited by 2D multiplanar views and manual sampling of ROIs. We analyzed a new 3D method to objectively quantify gadolinium plaque enhancement.

MATERIALS AND METHODS

Patients with stroke due to intracranial atherosclerotic disease underwent 7T high-resolution MR imaging. 3D segmentations of the plaque and its parent vessel were generated. Signal intensity probes were automatically extended from the lumen into the plaque and the vessel wall to generate 3D enhancement color maps. Plaque gadolinium (Gd) uptake was quantified from 3D color maps as gadolinium uptake = (µPlaque T1 + Gd -µPlaque T1/SDPlaque T1). Additional metrics of enhancement such as enhancement ratio, variance, and plaque-versus-parent vessel enhancement were also calculated. Conventional 2D measures of enhancement were collected for comparison.

RESULTS

Thirty-six culprit and 44 nonculprit plaques from 36 patients were analyzed. Culprit plaques had higher gadolinium uptake than nonculprit plaques (P < .001). Gadolinium uptake was the most accurate metric for identifying culprit plaques (OR, 3.9; 95% CI 2.1-8.3). Gadolinium uptake was more sensitive (86% versus 70%) and specific (71% versus 68%) in identifying culprit plaques than conventional 2D measurements. A multivariate model, including gadolinium uptake and plaque burden, identified culprit plaques with an 83% sensitivity and 86% specificity.

CONCLUSIONS

The new 3D color map method of plaque-enhancement analysis is more accurate for identifying culprit plaques than conventional 2D methods. This new method generates a new set of metrics that could potentially be used to assess disease progression.

Combined Transradial and Transfemoral Approach Using a Compliant Balloon for Emboli Protection at the Vertebral Artery During Subclavian Stenosis Stenting: 2-Dimensional Operative Video

Endovascular intervention has become the mainstay of treatment for subclavian artery stenosis in many centers, with high technical success and low complication rates.1,2 However, potential embolization during proximal subclavian artery intervention can lead to catastrophic posterior circulation ischemic complications.3-5 Although considered a rare complication, the presence of a contralateral hypoplastic vertebral artery with persisting anterograde vertebral blood flow on the affected side is likely to increase the risk of embolization.3 The use of embolic protection devices, such as filters and noncompliant balloons, has been previously described.3,6,7 However, there is still a risk of distal embolization and vessel injury with the use of these devices.7 We present a technical video of a patient in their 80s with left subclavian stenosis who underwent subclavian stent-assisted percutaneous transluminal angioplasty (SAPTA) using an anterograde-retrograde access technique with a dual-lumen compliant balloon catheter (Scepter XC; MicroVention, Aliso Viejo, California) placed at the proximal segment of the left vertebral artery. With this approach, the compliant balloon provides adequate protection while minimizing the risk of endothelial injury and distal embolization. Written informed consent was obtained for the procedure. Patient consent was waived because all health information was deidentified.

High resolution 7T MR imaging in characterizing culprit intracranial atherosclerotic plaques

BACKGROUND

Current imaging modalities underestimate the severity of intracranial atherosclerotic disease (ICAD). High resolution vessel wall imaging (HR-VWI) MRI is a powerful tool in characterizing plaques. We aim to show that HR-VWI MRI is more accurate at detecting and characterizing intracranial plaques compared to digital subtraction angiography (DSA), time-of-flight (TOF) MRA, and computed tomography angiogram (CTA).

METHODS

Patients with symptomatic ICAD prospectively underwent 7T HR-VWI. We calculated: degree of stenosis, plaque burden (PB), and remodeling index (RI). The sensitivity of detecting a culprit plaque for each modality as well as the correlations between different variables were analyzed. Interobserver agreement on the determination of a culprit plaque on every imaging modality was evaluated.

RESULTS

A total of 44 patients underwent HR-VWI. Thirty-four patients had CTA, 18 TOF-MRA, and 18 DSA. The sensitivity of plaque detection was 88% for DSA, 78% for TOF-MRA, and 76% for CTA. There's significant positive correlation between PB and degree of stenosis on HR-VWI MRI (p < 0.001), but not between PB and degree of stenosis in DSA (p = 0.168), TOF-MRA (p = 0.144), and CTA (p = 0.253). RI had a significant negative correlation with degree of stenosis on HR-VWI MRI (p = 0.003), but not on DSA (p = 0.783), TOF-MRA (p = 0.405), or CTA (p = 0.751). The best inter-rater agreement for culprit plaque detection was with HR-VWI (p = 0.001).

CONCLUSIONS

The degree of stenosis measured by intra-luminal techniques does not fully reflect the true extent of ICAD. HR-VWI is a more accurate tool in characterizing atherosclerotic plaques and may be the default imaging modality in clinical practice.

Quantitative Assessment of Ventriculostomy-Related Hemorrhage: A Volume-Based Classification System to Predict New Neurological Symptoms

BACKGROUND

Hemorrhage is one of the most feared complications following ventriculostomy placement. Current studies have assessed factors associated with increased risk of ventriculostomy-related hemorrhage (VRH). However, the clinical significance of VRH has not been determined.

OBJECTIVE

To correlate quantitative volumetric measurements of VRH with new neurological symptoms.

METHODS

A retrospective review of our institutional database of ventriculostomy patients during the last decade was performed. Patients' demographics and procedural details such as indication, number of passes and position of the catheter were recorded. VRH volume was quantified on noncontrast head computed tomography using the Picture Archiving Communication System (Carestream Vue®, Rochester, New York) semi-automated livewire segmentation tool. Patients with new neurological symptoms within 48 h of VRH were considered symptomatic. Several clinical confounders were ruled out. Logistic regression analyses were performed. The best volumetric cut-offs in predicting symptomatic VRH were determined through receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 3090 patients underwent ventriculostomy procedures and 179 (∼6%) developed VRH. A total of 41 (1.06%) patients with VRH developed new neurological symptoms. Only 12 (0.39%) were attributable to a new VRH. Multivariable logistic regression showed that volume of the hemorrhage (OR 1.17, P = .006) is the only significant predictor of symptomatic VRH. ROC curve analysis demonstrated that VRH volume <1.10 cc has 91.7% sensitivity to rule out symptomatic VRH, whereas a volume >7.59 cc has 95.5% specificity to predict symptomatic VRH.

CONCLUSION

Approximately 6% of patients developed postprocedural VRH, but only 0.4% were symptomatic. VRH volumes <1 cc are extremely unlikely to become symptomatic, whereas volumes >7.5 cc may predict development of new neurological deficits.

Ocular lateral deviation as a vestibular clinical sign of medial posterior inferior cerebellar artery strokes: A case report

We report a case of posterior circulation stroke that presented with a unique ocular vestibular sign called Ocular Lateral Deviation (OLD). OLD is eye deviation to one side that is made more prominent by brief eye closure. OLD has been reported to occur ipsilesional in a third of medullary strokes, and occasionally in other posterior fossa strokes. Here we report a case of acute stroke that presented with contralesional eye deviation consistent with OLD due to inferior vermis stroke. To our knowledge, this presentation has not been reported before. Clinicians should be aware of potential ocular manifestations of posterior circulation strokes, as these syndromes may not generate significant NIHSS scores and may be missed.

Factors and Outcomes Associated with National Institutes of Health Stroke Scale Scores in Acute Ischemic Stroke Patients Undergoing Thrombectomy in United States

BACKGROUND AND PURPOSE

The National Institutes of Health Stroke Scale (NIHSS) is the standard for assessing neurological deficits in acute ischemic stroke patients undergoing thrombectomy. However, data on NIHSS scores in patients undergoing thrombectomy at national-level studies in the United States are lacking.

METHODS

Acute ischemic stroke patients admitted between 2018 and 2021 were identified using ICD-10-CM codes from the Nationwide In-patient Sample, with NIHSS scores categorized into specific strata (0-9, 10-19, 20-29, 30-42). We analyzed the effect of NIHSS scores on in-hospital mortality, routine discharge without palliative care (based on discharge disposition), poor outcome defined by NIS SAH outcome measure, and length and costs of hospitalization after adjusting for potential confounders.

RESULTS

The NIHSS score strata among 108,990 acute ischemic stroke patients undergoing thrombectomy were: NIHSS score 0-9 (29.6%), 10-19 (40.6%), 20-29 (26.4%), and 30-42 (3.4%). Patients in the Midwest and West regions (adjusted odds ratio [adjusted OR] = 1.51, p=0.002 and adjusted OR = 1.63, p<0.001, respectively), those treated in rural hospitals (adjusted OR = 1.35, p=0.009) and those who were self-pay (adjusted OR = 1.51, p=0.048) had higher odds of being in higher NIHSS score strata. Patients in higher NIHSS score strata (NIHSS score 10-19, 20-29, and 30-42 had significantly lower odds of discharge home without palliative care (adjusted OR= 0.50, 0.32, and 0.22 respectively, all p<0.001) and higher odds of in-hospital mortality (adjusted OR = 1.51, 2.30, and 3.80 respectively, all p<0.001) compared to those in NIHSS score strata of 0-9. Patients in higher NIHSS score strata had significantly higher hospital stays and higher hospitalization costs.

CONCLUSIONS

We provide a comprehensive national-level analysis of NIHSS scores in acute ischemic stroke patients undergoing thrombectomy which may assist in understanding variations in outcomes and resource utilizations in United States.

Bilateral diaphragmatic dysfunction: A cause of persistent dyspnea in patients with post-acute sequelae of SARS-CoV-2

Persistent shortness of breath is one of the most common concerns reported by patients with post-acute sequelae of SARS-CoV-2. Here, we present a case of bilateral diaphragmatic paralysis as a cause shortness of breath that developed after SARS-CoV-2 infection. A middle-aged gentleman with history of sleep apnea and body mass index 27.9 kg/m2 presented to our post-COVID clinic with 3 months of dyspnea and orthopnea after contracting SARS-CoV-2 in November 2020. During acute infection, he was hospitalized for hypoxemia, which improved with steroids and supplemental oxygen. At 3 months, he continued to report dyspnea and orthopnea. On examination, he had tachycardia and increased respiratory rate with paradoxical respiratory abdominal movement. Chest imaging showed elevated bilateral hemidiaphragms without any parenchymal lung disease. Pulmonary function test revealed severe ventilatory defect with restrictive lung disease. He was diagnosed with bilateral diaphragmatic dysfunction which was confirmed by absence of evoked potentials in diaphragm after phrenic nerve stimulation bilaterally. He was advised to use continuous positive airway pressure machine to assist with breathing at night. At his last follow-up (1-year post-infection), he was symptomatically improving without specific interventions.

Effect of post thrombolytic intracerebral hemorrhage volume on 90-day outcomes in acute ischemic stroke patients

BACKGROUND AND PURPOSE

Post thrombolytic intracerebral hemorrhage (ICH) is associated with higher rate of death or disability in acute ischemic stroke patients. We investigated the relationship between post thrombolytic ICH volume and change in volume and death or disability at 90 days in acute ischemic stroke patients.

METHODS

We analyzed 110 patents recruited in the Safety Evaluation of 3K3A-APC in Ischemic Stroke (RHAPSODY) trial who received intravenous tissue plasminogen activator (tPA) followed by mechanical thrombectomy (if indicated) and 3K3A-APC or placebo. ICH volume was measured at Day 2 and Day 7 using susceptibility weighted sequence (SWI) on magnetic resonance imaging (MRI). We also calculated the post thrombolytic ICH volume change between Day 2 and Day 7. Outcomes were determined by using utility weighted modified Rankin scale (UW-mRs) at 90-days, Outcomes were determined by using utility weighted modified Rankin scale (UW-mRS) at 90 days. To minimize interpretation bias, outcome assessors were blinded to the treatment allocation and clinical data.We adjusted for age, gender, National Institutes of Health Stroke Scale (NIHSS) score (<10,10-19 and ≥20), location of hemorrhage (single basal ganglia hemorrhage, single lobar, single cerebellum, and multiple sites) in multivariate regression analysis.

RESULTS

A total of 88 (80%) of 110 patients had post thrombolytic ICH (mean volume 28.3 ml ± SD 62 ml). The strata of ICH volume were not associated with UW-mRs at 90 days: <20 cc (regression coefficient (RC)-0.05, p= 0.58), 20-39 cc (RC-0.22, p=0.17), or ≥40 cc (RC-0.34, p= 0.083) compared with no ICH after adjusting for potential confounders. Change in ICH mean volume 26.78 ml ±59.68, 52 had increase in volume) between Day 2 and day 7 was not associated with UW-mRS at 90 days (RC -67.71, p= 0.06).

CONCLUSIONS

We did not observe any independent effect of post thrombolytic ICH volume on death or disability in acute ischemic stroke patients. Although further studies must be done, our data suggest that strategies to prevent ICH expansion such as antifibrinolytic medications and reduction in ICH volume such as surgical evacuation may not reduce death or disability in acute ischemic stroke patients with post thrombolytic ICH.

Risk of new cerebral ischemic events in patients with symptomatic internal carotid artery stenosis while awaiting carotid stent placement

BACKGROUND AND PURPOSE

Although there is an emphasis on performing carotid artery stent (CAS) placement within 2 weeks after index event of transient ischemic attack (TIA) or minor stroke in patients with significant extracranial internal carotid artery (ICA) stenosis, the risks and characteristics of recurrent cerebral ischemic event while waiting for CAS placement are not well defined.

METHOD

We analyzed patients admitted to our institution over a 45-month period with symptomatic extracranial ICA stenosis. We identified any new cerebral ischemic events that occurred between index cerebral or retinal ischemic event and CAS placement and categorized them as TIA and minor or major ischemic strokes. We calculated the risk of new ipsilateral cerebral ischemic events between index cerebral or retinal ischemic event and CAS placement.

RESULTS

The mean age of 131 patients analyzed was 67 years (range: 47-94 years; 92 were men), and 94 and 37 patients had 70%-99% and 50%-69% severity of stenosis, respectively. The mean and median time intervals between index cerebral or retinal ischemic event and CAS performance were 28 (standard deviation [SD] 30) and 7 (interquartile range 33) days, respectively. A total of 9 of 131 patients (6.9%, 95% confidence interval 2.5%-11.2%) experienced new cerebral ischemic events over 3637 patient days of observation. The risk of new ipsilateral cerebral ischemic events was 2.5 per 1000 patient days of observation.

CONCLUSION

We estimated the risk of new ipsilateral cerebral ischemic events in patients with ICA stenosis ≥50% in severity while waiting for CAS placement to guide appropriate timing of procedure.

Effect of race/ethnicity on arterial recanalization following intravenous thrombolysis in acute ischemic stroke patients

INTRODUCTION

Several reports have identified that clinical outcomes such as death or disability in acute ischemic stroke (AIS) patients following intravenous (IV) tissue plasminogen activator (tPA) treatment can vary according to race and ethnicities. We determined the effect of race/ethnicity on rates of arterial recanalization in AIS patients with large vessel occlusion (LVO) after IV tPA.

METHODS

We analyzed 234 patients with LVO detected on computed tomographic angiography (CTA) who received IV tPA and subsequently underwent angiography for potential thrombectomy. The primary occlusion sites on CTA and digital subtracted angiography (DSA) were compared and a score was given to the level of recanalization with values ranging from 1 (complete recanalization), 2 (partial recanalization), or 3 (no recanalization).The effect of race/ethnicity were assessed for predicting vessel recanalization using the covariates of age, gender, time since stroke onset, tPA dose received, NIHSS (National Institute of Health Stroke Scale) score at baseline, and location of the occlusion, using logistic regression analysis.

RESULTS

Five patients (2.1%) were Hispanic or Latino, 8 (3.4%) Asian, 24 (10.3%) African American, and 197 (84.2%) White. A total of 50% had a distal ICA/proximal M1 occlusion, 20% distal M1 occlusion, and 16% single M2 occlusion. At the primary occlusion site, 44 (18.8%) had complete recanalization on post IV tPA angiogram, 17 (7.3%) had partial recanalization, and 165 (70.5%) had no recanalization. We did not find any association between race/ethnicity and vessel recanalization post IV tPA (Nonwhite combined [OR=1.49, p=0.351]; Asian [OR=1.460, p=0.650]; African American [OR=1.508, p=0.415]; White [OR=0.672, p=0.351]; ethnicity (Hispanic or Latino) [OR= 1.008, p=0.374]); Occlusion location (OR=0.189, p<0.001). Final TICI scores and mRS at 90 days were similar among the different groups.

CONCLUSION

Approximately 19% of patients had complete recanalization after IV tPA, but race and ethnicity did not seem to have an effect on arterial recanalization. Arterial recanalization was only affected by location of occlusion.