Characterizing coma in large vessel occlusion stroke

BACKGROUND

Coma is an unresponsive state of disordered consciousness characterized by impaired arousal and awareness. The epidemiology and pathophysiology of coma in ischemic stroke has been underexplored. We sought to characterize the incidence and clinical features of coma as a presentation of large vessel occlusion (LVO) stroke.

METHODS

Individuals who presented with LVO were retrospectively identified from July 2018 to December 2020. Coma was defined as an unresponsive state of impaired arousal and awareness, operationalized as a score of 3 on NIHSS item 1a.

RESULTS

28/637 (4.4%) patients with LVO stroke were identified as presenting with coma. The median NIHSS was 32 (IQR 29-34) for those with coma versus 11 (5-18) for those without (p < 0.0001). In coma, occlusion locations included basilar (13), vertebral (2), internal carotid (5), and middle cerebral (9) arteries. 8/28 were treated with endovascular thrombectomy (EVT), and 20/28 died during the admission. 65% of patients not treated with EVT had delayed presentations or large established infarcts. In models accounting for pre-stroke mRS, basilar occlusion location, intravenous thrombolysis, and EVT, coma independently increased the odds of transitioning to comfort care during admission (aOR 6.75; 95% CI 2.87,15.84; p < 0.001) and decreased the odds of 90-day mRS 0-2 (aOR 0.12; 95% CI 0.03,0.55; p = 0.007).

CONCLUSIONS

It is not uncommon for patients with LVO to present with coma, and delayed recognition of LVO can lead to poor outcomes, emphasizing the need for maintaining a high index of suspicion. While more commonly thought to result from posterior LVO, coma in our cohort was similarly likely to result from anterior LVO. Efforts to improve early diagnosis and care of patients with LVO presenting with coma are crucial.

Understanding the variability of the electrophysiologic laryngeal adductor reflex

OBJECTIVE

The laryngeal adductor reflex (LAR) is vital for airway protection and can be electrophysiologically obtained under intravenous general anesthesia (IGA). This makes the electrophysiologic LAR (eLAR) an important tool for monitoring of the vagus nerves and relevant brainstem circuitry during high-risk surgeries. We investigated the intra-class variability of normal and expected abnormal eLAR.

METHODS

Repeated measures of contralateral R1 (cR1) were performed under IGA in 58 patients. Data on presence/absence of cR2 and potential confounders were also collected. Review of neuroimaging, pathology and clinical exam, allowed classification into normal and expected abnormal eLAR groups. Using univariate and multivariate analysis we studied the variability of cR1 parameters and their differences between the two groups.

RESULTS

In both groups, cR1 latencies had coefficients of variation of <2%. In the abnormal group, cR1 had longer latencies, required higher activation currents and was more frequently desynchronized and unsustained; cR2 was more frequently absent.

CONCLUSIONS

cR1 latencies show high analytical precision for measurements. Delayed onset, difficult to elicit, desynchronized and unsustained cR1, and absence of cR2 signal an abnormal eLAR.

SIGNIFICANCE

Understanding the variability and behavior of normal and abnormal eLAR under IGA can aid in the interpretation of its changes during monitoring.

Relationship between prior statin therapy and radiological features and clinical outcomes of intracerebral hemorrhage

OBJECTIVES

A post-hoc analysis of the ICH Deferoxamine (i-DEF) trial was performed to examine any associations pre-ICH statin use may have with ICH volume, PHE volume, and clinical outcomes.

MATERIALS AND METHODS

Baseline characteristics were assessed. Various ICH and PHE parameters were measured via a quantitative, semi-automated method at baseline and follow-up CT scans 72-96 h later. A multivariable logistic regression model was created, adjusting for the variables that were significantly different on univariable analyses (p < 0.05), to assess any associations between pre-ICH statin use and measures of ICH and PHE, as well as good clinical outcome (mRS ≤2), at 90 and 180 days.

RESULTS

262 of 291 i-DEF participants had complete data available for analysis. 69 (26.3 %) used statins prior to ICH onset. Pre-ICH statin users had higher prevalences of hypertension, diabetes, and prior ischemic stroke; higher concomitant use of antihypertensives and antiplatelets; and higher blood glucose level at baseline. On univariable analyses, pre-ICH statin users had smaller baseline ICH volume and PHE volume on repeat scan, as well as smaller changes in relative PHE (rPHE) volume and edema extension distance (EED) between the baseline and repeat scans. In the multivariable analysis, none of the ICH and PHE measures or good clinical outcome was significantly associated with pre-ICH statin use.

CONCLUSION

Pre-ICH statin use was not associated with measures of ICH or PHE, their growth, or clinical outcomes. These findings do not lend support to either overall protective or deleterious effects from statin use before or after ICH.

Left ventricular hypertrophy and left atrial size are associated with ischemic strokes among non-vitamin K antagonist oral anticoagulant users

BACKGROUND

Ischemic strokes (IS) occurring in patients taking non-vitamin K antagonist oral anticoagulants (NOACs) are becoming increasingly more frequent. We aimed to determine the clinical, echocardiographic, and neuroimaging markers associated with developing IS in patients taking NOACs for atrial fibrillation.

METHODS

From a quaternary care center, clinical/radiologic data were collected from consecutive NOAC users with IS and age-matched controls without IS. Brain MRIs were reviewed for markers of cerebral small vessel disease. Variables with significant differences between groups were entered into a multivariable regression model to determine predictors of IS. Among IS patients, a Cox regression analysis was constructed to determine predictors of IS recurrence during follow-up.

RESULTS

112 patients with IS and 94 controls were included in the study. Variables significantly different between groups included apixaban use, dabigatran use, prior cerebrovascular events, hemoglobin A1c (HbA1c), left ventricular hypertrophy, left atrial volume index, and severe white matter hyperintensities. After multivariable adjustment, prior cerebrovascular events (aOR 23.86, 95% CI [6.02-94.48]), HbA1c levels (aOR 2.36, 95% CI [1.39-3.99]), left ventricular hypertrophy (aOR 2.73, 95% CI [1.11-6.71]) and left atrial volume index (aOR 1.05, 95% CI [1.01-1.08]) increased the risk of stroke, whereas apixaban use appeared to decrease the risk (aOR 0.38, 95% CI [0.16-0.92]). Malignancy was associated with IS recurrence (aHR 4.90, 95% CI [1.35-18.42]) after adjustment for age and chronic renal failure.

CONCLUSIONS

Prior cerebrovascular events, diabetes, left ventricular hypertrophy, and increased left atrial size are risk factors for developing an IS among NOAC users.

Neuroendovascular Surgery Applications in Craniocervical Trauma

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.

Mechanistic Implications of Cortical Superficial Siderosis in Patients With Mixed Location Intracerebral Hemorrhage and Cerebral Microbleeds

BACKGROUND AND OBJECTIVES

Hypertensive cerebral small vessel disease (HTN-cSVD) is the predominant microangiopathy in patients with a combination of lobar and deep cerebral microbleeds (CMBs) and intracerebral hemorrhage (mixed ICH). We tested the hypothesis that cerebral amyloid angiopathy (CAA) is also a contributing microangiopathy in patients with mixed ICH with cortical superficial siderosis (cSS), a marker strongly associated with CAA.

METHODS

Brain MRIs from a prospective database of consecutive patients with nontraumatic ICH admitted to a referral center were reviewed for the presence of CMBs, cSS, and nonhemorrhagic CAA markers (lobar lacunes, centrum semiovale enlarged perivascular spaces [CSO-EPVS], and multispot white matter hyperintensity [WMH] pattern). The frequencies of CAA markers and left ventricular hypertrophy (LVH), a marker for hypertensive end-organ damage, were compared between patients with mixed ICH with cSS (mixed ICH/cSS[+]) and without cSS (mixed ICH/cSS[-]) in univariate and multivariable models.

RESULTS

Of 1,791 patients with ICH, 40 had mixed ICH/cSS(+) and 256 had mixed ICH/cSS(-). LVH was less common in patients with mixed ICH/cSS(+) compared with those with mixed ICH/cSS(-) (34% vs 59%, p = 0.01). The frequencies of CAA imaging markers, namely multispot pattern (18% vs 4%, p < 0.01) and severe CSO-EPVS (33% vs 11%, p < 0.01), were higher in patients with mixed ICH/cSS(+) compared with those with mixed ICH/cSS(-). In a logistic regression model, older age (adjusted odds ratio [aOR] 1.04 per year, 95% CI 1.00-1.07, p = 0.04), lack of LVH (aOR 0.41, 95% CI 0.19-0.89, p = 0.02), multispot WMH pattern (aOR 5.25, 95% CI 1.63-16.94, p = 0.01), and severe CSO-EPVS (aOR 4.24, 95% CI 1.78-10.13, p < 0.01) were independently associated with mixed ICH/cSS(+) after further adjustment for hypertension and coronary artery disease. Among ICH survivors, the adjusted hazard ratio of ICH recurrence in patients with mixed ICH/cSS(+) was 4.65 (95% CI 1.38-11.38, p < 0.01) compared with that in patients with mixed ICH/cSS(-).

DISCUSSION

The underlying microangiopathy of mixed ICH/cSS(+) likely includes both HTN-cSVD and CAA, whereas mixed ICH/cSS(-) is likely driven by HTN-cSVD. These imaging-based classifications can be important to stratify ICH risk but warrant confirmation in studies incorporating advanced imaging/pathology.

Aspiration Versus Stent‐Retriever as First‐Line Endovascular Therapy Technique for Primary Medium and Distal Intracranial Occlusions: A Propensity‐Score Matched Multicenter Analysis

BACKGROUND

For acute proximal intracranial artery occlusions, contact aspiration may be more effective than stent‐retriever for first‐line reperfusion therapy. Due to the lack of data regarding medium vessel occlusion thrombectomy, we evaluated outcomes according to first‐line technique in a large, multicenter registry.

METHODS

Imaging, procedural, and clinical outcomes of patients with acute proximal medium vessel occlusions (M2, A1, or P1) or distal medium vessel occlusions (M3, A2, P2, or further) treated at 37 sites in 10 countries were analyzed according to first‐line endovascular technique (stent‐retriever versus aspiration). Multivariable logistic regression and propensity‐score matching were used to estimate the odds of the primary outcome, expanded Thrombolysis in Cerebral Infarction score of 2b–3 (“successful recanalization”), as well as secondary outcomes (first‐pass effect, expanded Thrombolysis in Cerebral Infarction 2c‐3, intracerebral hemorrhage, and 90‐day modified Rankin scale, 90‐day mortality) between treatment groups.

RESULTS

Of the 440 included patients (44.5% stent‐retriever versus 55.5% aspiration), those treated with stent‐retriever had lower baseline Alberta Stroke Program Early Computed Tomography Scale scores (median 8 versus 9; P <0.01), higher National Institutes of Health Stroke Scale scores (median 13 versus 11; P =0.02), and nonsignificantly fewer medium‐distal occlusions (M3, A2, P2, or other: 17.4% versus 23.8%; P =0.10). Use of a stent‐retriever was associated with 15% lower odds of successful recanalization (odds ratio [OR], 0.85; [95% CI 0.74–0.98]; P =0.02), but this was not significant after multivariable adjustment in the total cohort (adjusted OR, 0.88; [95% CI 0.72–1.09]; P =0.24), or in the propensity‐score matched cohort (n=105 in each group) (adjusted OR, 0.94; [95% CI 0.75–1.18]; P =0.60). There was no significant association between technique and secondary outcomes in the propensity‐score matched adjusted models.

CONCLUSION

In this large, diverse, multinational medium vessel occlusion cohort, we found no significant difference in imaging or clinical outcomes with aspiration versus stent‐retriever thrombectomy.

Peak width of skeletonized mean diffusivity and cognitive performance in cerebral amyloid angiopathy

Background

Cerebral Amyloid Angiopathy (CAA) is a cerebral small vessel disease that can lead to microstructural disruption of white matter (WM), which can be measured by the Peak Width of Skeletonized Mean Diffusivity (PSMD). We hypothesized that PSMD measures would be increased in patients with CAA compared to healthy controls (HC), and increased PSMD is associated with lower cognitive scores in patients with CAA.

Methods

Eighty-one probable CAA patients without cognitive impairment who were diagnosed with Boston criteria and 23 HCs were included. All subjects underwent an advanced brain MRI with high-resolution diffusion-weighted imaging (DWI). PSMD scores were quantified from a probabilistic skeleton of the WM tracts in the mean diffusivity (MD) image using a combination of fractional anisotropy (FA) and the FSL Tract-Based Spatial Statistics (TBSS) algorithm (www.psmd-marker.com). Within CAA cohort, standardized z-scores of processing speed, executive functioning and memory were obtained.

Results

The mean of age and sex were similar between CAA patients (69.6 ± 7.3, 59.3% male) and HCs (70.6 ± 8.5, 56.5% male) (p = 0.581 and p = 0.814). PSMD was higher in the CAA group [(4.13 ± 0.94) × 10-4 mm2/s] compared to HCs [(3.28 ± 0.51) × 10-4 mm2/s] (p < 0.001). In a linear regression model corrected for relevant variables, diagnosis of CAA was independently associated with increased PSMD compared to HCs (ß = 0.45, 95% CI 0.13-0.76, p = 0.006). Within CAA cohort, higher PSMD was associated with lower scores in processing speed (p < 0.001), executive functioning (p = 0.004), and memory (0.047). Finally, PSMD outperformed all other MRI markers of CAA by explaining most of the variance in models predicting lower scores in each cognitive domain.

Discussion

Peak Width of Skeletonized Mean Diffusivity is increased in CAA, and it is associated with worse cognitive scores supporting the view that disruption of white matter has a significant role in cognitive impairment in CAA. As a robust marker, PSMD can be used in clinical trials or practice.

Abstract TMP76: Left Atrial Appendage Closure In Atrial Fibrillation Patients At High Intracranial Hemorrhage Risk

Background: Lifelong oral anticoagulant (OAC) use is associated with higher intracranial hemorrhage (ICH) risk in nonvalvular atrial fibrillation (NVAF) patients. We aimed to assess the long-term outcomes of left atrial appendage closure (LAAC) in NVAF patients at high baseline ICH risk, as LAAC was FDA-approved for NVAF patients who have a reasonable rationale to seek a nonpharmacological alternative to lifelong OAC use.

Methods: We collected baseline and follow up data from consecutive NVAF patients who had LAAC because of either past ICH or finding cerebral microbleeds (CMB) on MRI without ICH (CMB-only). The outcome measures were the occurrence of ICH or acute ischemic stroke (AIS) after LAAC.

Results: Out of a total of 644 LAAC performed in a single hospital system between 2015-2022, 142 NVAF patients had LAAC with WATCHMAN because of past ICH or CMB-only. Their mean age was 75.8± 7.6, 41 were female (29%). Mean CHA 2 DS 2 -VASc score was 5.24±1.4. Of the 142 patients, 67 (47.2%) had intraparenchymal hemorrhage (IPH, 52% related to cerebral amyloid angiopathy [CAA]), 19 (13.4%) had non-traumatic subdural hemorrhage (SDH), 36 (25.3%) had traumatic ICH (T-ICH), and 20 (14.08%) were CMB-only (65% with CAA pattern). Eighty-one patients were discharged on OAC (57%) and 133 patients were not taking OAC at 1 year (94%). Over a mean 1.98 years follow up, one patient had recurrent non-traumatic IPH (incidence rate [IR] 0.36 per 100 patient-years), four had traumatic ICH/SDH due to severe falls (IR 1.4%/year), and five had AIS (IR 1.78%/year).

Conclusions: In NVAF patients at high ICH risk, our results show a 74% decrease in AIS risk (actual 1.76%/year vs expected 6.8%/year based on CHA 2 DS 2 -VASc). Despite the very high ICH risk population studied including at least 48 CAA patients, only one patient had a recurrent IPH after LAAC. LAAC should be considered in NVAF patients at high ICH risk and studied in RCTs in this cohort.

Abstract 160: Etiologies Of Intracerebral Hemorrhage In Patients With Atrial Fibrillation On Or Off Oral Anticoagulants: The Neuro-Afib Study

Background: Intracerebral hemorrhage (ICH) is the most feared complication of oral anticoagulants (OAC) used to prevent ischemic strokes (IS) in patients with atrial fibrillation (AF). As different ICH etiologic factors correspond to different ICH risks, we aimed to present the causes of ICH in AF patients who were or were not using OAC, based on data from a multicenter contemporary cohort.

Methods: The Neuro-AFib study is a multicenter effort to elucidate the current causes and consequences of IS and ICH in AF patients. Detailed clinical, laboratory and multimodal imaging data were collected from consecutive patients with AF admitted to 15 US stroke centers with an IS or ICH between 1/2018-12/2019. Etiologic factors of AF patients who were admitted with ICH on OAC (OAC-ICH) and off OAC (nonOAC-ICH) will be compared.

Results: A total of 868 patients presented with ICH and had a diagnosis of AF, either previously known (88%) or diagnosed during admission (12%). 571 patients (66%) were on OAC at the time of their ICH of whom 58% were on direct OAC (DOAC), 40% on warfarin and 2% on heparin. OAC-ICH patients were older than nonOAC-ICH (76.6±10 vs 74.4±13, p=0.006) while sex distribution was the same in both groups (43% female). CHA 2 DS 2 -VASC was higher in OAC-ICH (4.3±1.6 vs 3.9±1.9, p=0.001) but HAS-BLED score was the same in both groups (2.7±1.1). Cerebral amyloid angiopathy (CAA) was diagnosed in 42.5% of the ICH patients based on modified Boston criteria while hypertensive cerebral small vessel disease (HTN-cSVD) in 57.5%. HTN-cSVD was the more common ICH etiology among OAC-ICH (65%) compared to nonOAC-ICH (49%). Among OAC-ICHs, DOAC-related ICHs tended to be more commonly of hypertensive etiology when compared to warfarin-ICH (p=0.09).

Conclusions: Our study is the first to report the etiologic mechanisms of ICH in AF patients on or off OAC. CAA is known to be a major cause of OAC-ICH with exceedingly high recurrence rates. Despite this fact, HTN-cSVD was more common among OAC-ICH (especially DOAC-ICH) patients, supporting the view that the presence/absence of HTN-cSVD risk markers such as deep microbleeds are as important as CAA-markers in determining the optimal stroke prevention method in AF patients (left atrial appendage closure vs lifelong OAC).

Abstract 162: Molecular And Microstructural Alterations In Cerebral Amyloid Angiopathy-related Hemorrhagic Manifestations

Background and Purpose: We aimed to compare the amyloid load and degree of microstructural injury among Cerebral Amyloid Angiopathy (CAA) patients with either higher lobar cerebral microbleed (CMB) counts or higher cortical superficial siderosis (cSS) extent against CAA patients with lower hemorrhagic load.

Methods: The study included 38 cognitively healthy probable CAA patients with lobar intracerebral hemorrhage (ICH) and 38 age, sex-matched healthy controls (HC) who underwent advanced MRI, and Pittsburgh Compound B (PiB) PET scans. Patients were categorized into CMB-Dominant (CMB-D) and cSS-Dominant (cSS-D) based on the number and extent of CMB and cSS using previously identified cutoffs (Figure). The mean global cortical amyloid load was calculated from PiB-PET scans and represented by PiB-DVR. Within the CAA cohort, the Peak Width of Skeletonized Mean Diffusivity (PSMD) was calculated from diffusion MRIs and used as a marker of microstructural integrity.

Results: Patients with CAA had significantly higher PiB-DVR than HCs (1.40±0.24 vs. 1.19±0.22, p<0.001). Both CMB-D and cSS-D CAA patients had significantly higher amyloid and increased (worse) PSMD compared to CAA patients with a non-dominant low hemorrhagic load (Figure). These results did not change in separate regression models corrected for age and sex. PiB-DVR significantly correlated with increased PSMD (r=0.346, p=0.033).

Conclusions: Our findings support the view that vascular amyloid load drives higher CMB counts, more extensive cSS, and microstructural injury in patients with CAA. Furthermore, the correlations among these markers suggest that these MRI-based categorizations (CMB-D and cSS-D patients) can be used for disease staging and further research.

Abstract WP118: Mechanistic Implications Of Cortical Superficial Siderosis In Patients With Mixed Location Intracerebral Hemorrhage And Cerebral Microbleeds

Introduction: Hypertensive cerebral small vessel disease (HTN-cSVD) is the predominant microangiopathy in patients with a combination of lobar and deep cerebral microbleeds (CMBs) and intracerebral hemorrhage (mixed ICH/CMB). We tested the hypothesis that cerebral amyloid angiopathy (CAA) is also a contributing microangiopathy in mixed ICH/CMB patients with cortical superficial siderosis (cSS), a marker that is strongly associated with CAA.

Methods: Brain MRIs from a prospective database of consecutive non-traumatic ICH patients admitted to a single referral center (2003 to 2019) were reviewed for the presence of CMBs, cSS, and non-hemorrhagic CAA markers (lobar lacunes, centrum semiovale enlarged perivascular spaces (CSO-EPVS), and multispot pattern of leukoaraiosis). The frequency of CAA markers and left ventricular hypertrophy (LVH), a marker for hypertensive end-organ damage, were compared between mixed ICH/CMB patients with cSS (mixed +cSS ) and without cSS (mixed -cSS ) in univariate and multivariate models.

Results: Of the 1824 ICH patients, 40 had mixed +cSS and 256 had mixed -cSS . LVH was less common in patients with mixed +cSS compared to those with mixed -cSS (34% vs. 59%, p = 0.01). The frequency of multispot pattern (18% vs. 4%, p < 0.01) and severe CSO-EPVS (33% vs. 11%, p < 0.01) were higher in patients with mixed +cSS compared to mixed -cSS , whereas lobar lacune frequency was similar (23% vs. 20%, p = 0.67). In a logistic regression model, older age (aOR 1.04 per year, 95% CI [1.01-1.08], p = 0.01), presence of multispot pattern (aOR 5.82, 95% CI [1.82-18.60], p < 0.03), severe CSO-EPVS (aOR 4.08, 95% CI [1.73-9.61], p < 0.01), and LVH (aOR 0.43, 95% CI [0.20-0.94], p = 0.03) were independently associated with mixed +cSS after further adjustment for sex and hypertension (Table).

Conclusions: CAA and HTN-cSVD appear to confer injury in patients with mixed ICH/CMB and cSS, a finding that warrants confirmation in studies incorporating advanced imaging/pathology.

Abstract 33: Risk Scores And Brain Mri Markers In Distinguishing Ischemic Stroke And Intracerebral Hemorrhage Risk Among Atrial Fibrillation Patients: The Neuro-Afib Study

Background: Recent studies cast doubt on the accuracy of the most-commonly used risk scores (CHA 2 DS 2 -VASC and HAS-BLED) in differentiating the risk of acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH) among patients with fibrillation (AF). Because of the importance of AIS/ICH risk determination for choice of proper preventive approaches, we aimed to compare the value of these risk scores and brain MRI markers to differentiate the occurrence of AIS and ICH in a large cohort of AF-related strokes.

Methods: The Neuro-AFib study is a multicenter effort to elucidate the causes and consequences of AIS and ICH in AF patients. Demographics, CHA 2 DS 2 -VASC and HAS-BLED scores, and ischemic/hemorrhagic brain MRI markers were compared between AF patients admitted with AIS and ICH to 15 academic stroke centers in the US between 1/2018-12/2019.

Results: Of 5694 stroke admissions with AF, 4826 (84.8%) had AIS and 868 (15.2%) ICH. Mean age was similar between groups (75.9±11.5 vs 76.6±11.9, p=0.1), more ICH patients were male (57% vs 50%). Pre-index event CHA 2 DS 2 -VASC (4.14±1.6 vs 4.22±1.6) and HAS-BLED (2.71±1.09 vs 2.68±1.13) were similar between groups [both p>0.2]. Cerebral microbleeds (CMB, 56% vs 33.5%), cortical superficial siderosis (cSS, 15% vs 9.4%), and moderate-to-severe leukoaraiosis (41% vs 33.4%) were more commonly found among ICH patients compared to AIS (all p<0.001). Chronic lacunar infarcts (43.5% vs 39.5%, p=0.03) and chronic non-lacunar infarcts (29% vs 18%, p<0.001) were more commonly found in AIS. In a multivariable logistic regression model that included all variables above, male sex, presence of CMBs, cSS, moderate-to-severe leukoaraiosis were associated with ICH, chronic non-lacunar infarcts with AIS (all p<0.005), while CHA 2 DS 2 -VASC (p=0.9) and HAS-BLED (p=0.9) were not related to the stroke type.

Conclusions: Data from our multicenter study confirm the lack of specificity of CHA 2 DS 2 -VASC and HAS-BLED to categorize the risk of AIS vs ICH in AF patients. The chronic MRI findings (CMB, cSS, moderate-to-severe leukoaraiosis, chronic infarcts) should be incorporated into risk scores, and their predictive value for AIS and ICH should be investigated in prospective studies to select optimal stroke prevention methods in AF patients.

Abstract WP140: Coma As A Presentation For Large Vessel Occlusion Stroke

Introduction: Coma is an unresponsive state of disordered consciousness characterized by impaired arousal and awareness. While coma has been studied in the context of traumatic brain injury, the epidemiology and pathophysiology of coma in ischemic stroke has been underexplored. We sought to characterize the incidence and clinical features of coma as a presentation of large vessel occlusion (LVO) stroke.

Methods: Individuals who presented with LVO were identified from July 2018 to December 2020. Coma was defined as an unresponsive state of impaired arousal and awareness, operationalized as a score of 3 on NIHSS item 1a: responds only with reflex motor or autonomic effects or totally unresponsive, flaccid, and areflexic.

Results: A total of 28/638 (4.4%) patients with large vessel occlusion stroke were identified as presenting with coma. The median age was 65 (IQR 48-78), and 57% were female. The median NIHSS was 32 (IQR 29-34). Occlusion locations included basilar (10), vertebral (2), P1 posterior cerebral (2), internal carotid (4), M1 middle cerebral (6), and M2 middle cerebral arteries (4). In all 14 patients with anterior LVO, the acute LVO was unilateral. Of these 14, 6 had evidence of acute or chronic stroke involving the contralateral hemisphere; 1 experienced seizure; 1 experienced cardiac arrest; and 1 had chronic occlusion of the contralateral ICA. Overall, 20/28 died during the admission. Of those who died, 9 presented with anterior LVO and 11 with posterior LVO. Eight patients were treated with EVT. For those not treated, reasons included established infarct with ASPECTS <6 (11), delayed presentation (2), pre-stroke disability and goals of care (3), and absence of intracranial proximal occlusion on repeat imaging (2).

Conclusions: It is not uncommon for patients with LVO stroke to present with coma, and 65% of patients not treated with EVT had delayed presentations or large established infarcts, emphasizing the need for maintaining a high index of suspicion. While more commonly thought to result from posterior LVO, coma in our cohort was similarly likely to result from anterior LVO. Further study of these patients may shed light on the pathophysiology of coma. Efforts to improve early diagnosis and care are crucial given their poor outcomes.

Abstract TP128: Hemorrhagic Transformation After Endovascular Thrombectomy Is Associated With Basal Ganglia Infarct Volume

Introduction: With continued expansion in indications for endovascular thrombectomy (EVT), understanding the pathophysiology of reperfusion injury and the risks of hemorrhagic transformation (HT) becomes increasingly important. Pre-EVT infarct topography may have implications for treatment decisions acutely (e.g. stenting), and with post EVT care (e.g. antithrombotics). We sought to quantify region-specific volumes of infarcted tissue on pre-EVT MRI, understand their importance for HT, and identify associations with clinical and imaging characteristics.

Methods: Patients with pre-EVT MRI were identified from a prospectively maintained database. Each patient’s diffusion weighted sequence underwent manual infarct delineation and was registered to a standard space for overlay with cortical, subcortical, and white matter atlases. HT was defined as ECASS PH1 or PH2. Variables with p<0.10 in univariate analyses were included in multivariable models.

Results: A total of 165 participants [median age 69 (IQR 56-79), 56% women] were identified. Intravenous alteplase was administered to 52%; 70% achieved TICI 2b-3 reperfusion. HT occurred in 8%. The distribution of pre-EVT infarcts was 48% (38-60%) white matter, 23% (6-47%) cortex, and 15% (4-28%) basal ganglia. Pre-EVT infarct volumes [median (IQR)] were 22 cc (12-43 cc) for total, 11 cc (6-19 cc) for white matter, 5 cc (1-19 cc) for cortex, and 3 cc (1-6 cc) for basal ganglia infarct. Paramagnetic sequences showed 3% had petechial hemorrhage and 40% had susceptibility vessel sign. Basal ganglia infarct volume was independently associated with HT (OR=1.342, 95%CI=1.002,1.797) in a model including white matter infarct volume, cortex infarct volume, smoking, and puncture-to-recanalization time. Basal ganglia infarct volume was linked to susceptibility vessel sign (Beta=0.233, p=0.006) and NIHSS (Beta=0.220, p=0.012), when controlling for total infarct volume.

Conclusions: Greater basal ganglia infarct volume was associated with a higher risk of HT when accounting for infarct volumes in other regions. Susceptibility vessel sign was associated with basal ganglia infarct volume, which may be related to acute middle cerebral artery perforator occlusion.

Abstract WP122: Effect Of Prior Exposure To Statin Therapy On Clinical And Radiological Features Of Intracerebral Hemorrhage: A Post-hoc Analysis Of The I-def Trial

Background: Conflicting data exist regarding the relationship between prior statin use and perihematomal edema (PHE) in patients with intracerebral hemorrhage (ICH). We performed a post-hoc analysis of the ICH Deferoxamine (i-DEF) trial to examine whether there is an association between statin use prior to the onset of ICH and baseline PHE volume and its growth on 72-96 hour follow-up scans.

Methods: Statin use prior to the study enrollment was assessed, and CT scans were performed at presentation and after 24 hours after the completion of a 3-day infusion of either saline or deferoxamine (DFO). ICH volumes and various PHE parameters were measured semi-quantititavely using Analyze imaging software. Multivariable logistic regression model was created, adjusting for the variables that were significantly different on univariable analyses, to assess for any associations between prior statin use and measures of ICH and PHE. Bonferroni correction was applied for multiple testing.

Results: Seventy-four (25.4%) of 291 participants in i-DEF used statin prior to ICH onset. On univariable analyses, those with prior statin use had higher prevalences of hypertension, diabetes, and prior ischemic stroke, as well as concomitant antihypertensive and antiplatelet uses. Patients with prior statin use had smaller baseline ICH volume, absolute PHE (aPHE) volume, and edema extension distance (EED). Greater hematoma volume growth, baseline relative PHE (rPHE) volume, and reduction in rPHE volume from baseline to follow-up scans were also seen in those with prior statin use. On multivariable analysis, none of the measures of ICH and PHE was significantly associated with prior statin use, after adjusting for multiple testing.

Conclusion: In this post-hoc analysis of a randomized controlled trial with standardized imaging and functional assessments, we did not find significant associations between pre-ICH statin use and measures of ICH or PHE volumes and their growth.

Improving detection of cerebral small vessel disease aetiology in patients with isolated lobar intracerebral haemorrhage

BACKGROUND AND PURPOSE

We evaluate whether non-haemorrhagic imaging markers (NHIM) (white matter hyperintensity patterns, lacunes and enlarged perivascular spaces (EPVS)) can discriminate cerebral amyloid angiopathy (CAA) from hypertensive cerebral small vessel disease (HTN-cSVD) among patients with isolated lobar intracerebral haemorrhage (isolated-LICH).

METHODS

In patients with isolated-LICH, four cSVD aetiologic groups were created by incorporating the presence/distribution of NHIM: HTN-cSVD pattern, CAA pattern, mixed NHIM and no NHIM. CAA pattern consisted of patients with any combination of severe centrum semiovale EPVS, lobar lacunes or multiple subcortical spots pattern. HTN-cSVD pattern consisted of any HTN-cSVD markers: severe basal ganglia PVS, deep lacunes or peribasal ganglia white matter hyperintensity pattern. Mixed NHIM consisted of at least one imaging marker from either pattern. Our hypothesis was that patients with HTN-cSVD pattern/mixed NHIM would have a higher frequency of left ventricular hypertrophy (LVH), which is associated with HTN-cSVD.

RESULTS

In 261 patients with isolated-LICH, CAA pattern was diagnosed in 93 patients, HTN-cSVD pattern in 53 patients, mixed NHIM in 19 patients and no NHIM in 96 patients. The frequency of LVH was similar among those with HTN-cSVD pattern and mixed NHIM (50% vs 39%, p=0.418) but was more frequent in HTN-cSVD pattern compared with CAA pattern (50% vs 20%, p<0.001). In a regression model, HTN-cSVD pattern (OR: 7.38; 95% CI 2.84 to 19.20) and mixed NHIM (OR: 4.45; 95% CI 1.25 to 15.90) were found to be independently associated with LVH.

CONCLUSION

Among patients with isolated-LICH, NHIM may help differentiate HTN-cSVD from CAA, using LVH as a marker for HTN-cSVD.

Understanding Delays in MRI-based Selection of Large Vessel Occlusion Stroke Patients for Endovascular Thrombectomy

PURPOSE

Given the efficacy of endovascular thrombectomy (EVT), optimizing systems of delivery is crucial. Magnetic resonance imaging (MRI) is the gold standard for evaluating tissue viability but may require more time to obtain and interpret. We sought to identify determinants of arrival-to-puncture time for patients who underwent MRI-based EVT selection in a real-world setting.

METHODS

Patients were identified from a prospectively maintained database from 2011-2019 that included demographics, presentations, treatments, and outcomes. Process times were obtained from the medical charts. MRI times were obtained from time stamps on the first sequence. Linear and logistic regressions were used to infer explanatory variables of arrival-to-puncture times and effects of arrival-to-puncture time on functional outcomes.

RESULTS

In this study 192 patients (median age 70 years, 57% women, 12% non-white) underwent MRI-based EVT selection. 66% also underwent computed tomography (CT) at the hub before EVT. General anesthesia was used for 33%. Among the entire cohort, the median arrival-to-puncture was 102 min; however, among those without CT it was 77 min. Longer arrival-to-puncture times independently reduced the odds of 90-day good outcome (∆mRS ≤ 2 from pre-stroke, aOR = 0.990, 95%CI = 0.981-0.999, p = 0.040) when controlling for age, NIHSS, and good reperfusion (TICI 2b-3). Independent determinants of longer arrival-to-puncture were CT plus MRI (β = 0.205, p = 0.003), non-white race/ethnicity (β = 0.162, p = 0.012), coronary disease (β = 0.205, p = 0.001), and general anesthesia (β = 0.364, p < 0.0001).

CONCLUSION

Minimizing arrival-to-puncture time is important for outcomes. Real-world challenges exist in an MRI-based EVT selection protocol; avoiding double imaging is key to saving time. Racial/ethnic disparities require further study. Understanding variables associated with delay will inform protocol changes.

Clinical and neuroimaging risk factors associated with the development of intracerebral hemorrhage while taking direct oral anticoagulants

BACKGROUND AND AIMS

Intracerebral hemorrhage (ICH) associated with direct oral anticoagulant (DOAC) usage confers significant mortality/disability. We aimed to understand the clinical and neuroimaging features associated with developing ICH among DOAC users.

METHODS

Clinical and radiological data were collected from consecutive DOAC users with ICH (DOAC-ICH) and age-matched controls without ICH from a single referral center. The frequency/distribution of MRI markers of hemorrhage risk were assessed. Baseline demographics and neuroimaging markers were compared in univariate tests. Significant associations (p < 0.1) were entered into a multivariable regression model to determine predictors of ICH.

RESULTS

86 DOAC-ICH and 94 ICH-free patients were included. Diabetes, coronary artery disease, prior ischemic stroke, smoking history, and antiplatelet usage were more common in ICH patients than ICH-free DOAC users. In the neuroimaging analyses, severe white matter hyperintensities (WMHs), lacunes, cortical superficial siderosis (cSS), and cerebral microbleeds (CMBs) were more common in the ICH cohort than the ICH-free cohort. In the multivariable regression, diabetes [OR 3.53 95% CI (1.05-11.87)], prior ischemic stroke [OR 14.80 95% CI (3.33-65.77)], smoking history [OR 3.08 95% CI (1.05-9.01)], CMBs [OR 4.07 95% CI (1.45-11.39)], and cSS [OR 39.73 95% CI (3.43-460.24)] were independently associated with ICH.

CONCLUSIONS

Risk factors including diabetes, prior stroke, and smoking history as well as MRI biomarkers including CMBs and cSS are associated with ICH in DOAC users. Although screening MRIs are not typically performed prior to initiating DOAC therapy, these data suggest that patients of high-hemorrhagic risk may be identified.

Risk factors for neurological complications in left-sided infective endocarditis

BACKGROUND AND PURPOSE

Neurological complications following infective endocarditis (IE) directly contribute to long-term morbidity. We examined the risk factors for different neurological complications of left-sided IE.

METHODS

Using a database of consecutive adults admitted to a health system with left-sided IE from 2015 to 2019, the frequency of cerebral infarcts, intraparenchymal hemorrhage, cerebral microbleeds (CMB), mycotic aneurysm, and encephalopathy was determined. Variables with significant differences comparing each neurological complication (p < 0.1) were entered into regression models along with age to determine predictors.

RESULTS

211 patients with mean age 54 (±18) years, and 69 (33%) females were included. Infarcts were found in 118 (56%) patients, intraparenchymal hemorrhage was found in 17 (8%) patients, CMB were found in 58 (27%) patients, mycotic aneurysms were found in 22 (10%) patients, and encephalopathy occurred in 16 (8%) patients. In multivariable models, vegetation size ≥15 mm was associated with a higher risk of infarcts (aOR 2.26, 95% CI (1.12-4.57)), and the presence of a mycotic aneurysm was a risk factor for intraparenchymal hemorrhage (aOR 18.79, 95% CI (3.97-88.97)). Prosthetic valves (aOR 2.89, 95% CI (1.11-7.54)) and Staphylococcus aureus infection (aOR 3.50, 95% CI (1.08-11.36)) were associated with CMB. No risk factors emerged as predictors of encephalopathy.

CONCLUSIONS

Large vegetation size is associated with stroke in patients with IE. Mycotic aneurysms are found at a higher frequency in young patients and are the primary cause of intraparenchymal hemorrhage. CMB may be related to prosthetic valves and Staphylococcus aureus infection.

Idiopathic primary intraventricular hemorrhage and cerebral small vessel disease

BACKGROUND

Although primary intraventricular hemorrhage is frequently due to trauma or vascular lesions, the etiology of idiopathic primary intraventricular hemorrhage (IP-IVH) is not defined.

AIMS

Herein, we test the hypothesis that cerebral small vessel diseases (cSVD) including hypertensive cSVD (HTN-cSVD) and cerebral amyloid angiopathy are associated with IP-IVH.

METHODS

Brain magnetic resonance imaging from consecutive patients (January 2011 to September 2019) with non-traumatic intracerebral hemorrhage from a single referral center were reviewed for the presence of HTN-cSVD (defined by strictly deep or mixed-location intracerebral hemorrhage/cerebral microbleeds) and cerebral amyloid angiopathy (applying modified Boston criteria).

RESULTS

Forty-six (4%) out of 1276 patients were identified as having IP-IVH. Among these, the mean age was 74.4 ± 12.2 years and 18 (39%) were females. Forty (87%) had hypertension, and the mean initial blood pressure was 169.2 ± 40.4/88.8 ± 22.2 mmHg. Of the 35 (76%) patients who received a brain magnetic resonance imaging, two (6%) fulfilled the modified Boston criteria for possible cerebral amyloid angiopathy and 10 (29%) for probable cerebral amyloid angiopathy. Probable cerebral amyloid angiopathy was found at a similar frequency when comparing IP-IVH patients to the remaining patients with primary intraparenchymal hemorrhage (P-IPH) (27%, p = 0.85). Furthermore, imaging evidence for HTN-cSVD was found in 8 (24%) patients with IP-IVH compared to 209 (28%, p = 0.52) patients with P-IPH.

CONCLUSIONS

Among IP-IVH patients, cerebral amyloid angiopathy was found in approximately one-third of patients, whereas HTN-cSVD was detected in 23%-both similar rates to P-IPH patients. Our results suggest that both cSVD subtypes may be associated with IP-IVH.

Effect of vascular amyloid on white matter disease is mediated by vascular dysfunction in cerebral amyloid angiopathy

We postulated that vascular dysfunction mediates the relationship between amyloid load and white matter hyperintensities (WMH) in cerebral amyloid angiopathy (CAA). Thirty-eight cognitively healthy patients with CAA (mean age 70 ± 7.1) were evaluated. WMH was quantified and expressed as percent of total intracranial volume (pWMH) using structural MRI. Mean global cortical Distribution Volume Ratio representing Pittsburgh Compound B (PiB) uptake (PiB-DVR) was calculated from PET scans. Time-to-peak [TTP] of blood oxygen level-dependent response to visual stimulation was used as an fMRI measure of vascular dysfunction. Higher PiB-DVR correlated with prolonged TTP (r = 0.373, p = 0.021) and higher pWMH (r = 0.337, p = 0.039). Prolonged TTP also correlated with higher pWMH (r = 0.485, p = 0.002). In a multivariate linear regression model, TTP remained independently associated with pWMH (p = 0.006) while PiB-DVR did not (p = 0.225). In a bootstrapping model, TTP had a significant indirect effect (ab = 0.97, 95% CI: 0.137-2.461), supporting that the association between PiB-DVR and pWMH is mediated by TTP response. There was no longer a direct effect independent of the hypothesized pathway. Our study suggests that the effect of vascular amyloid load on white matter disease is mediated by vascular dysfunction in CAA. Amyloid lowering strategies might prevent pathophysiological processes leading to vascular dysfunction, therefore limiting ischemic brain injury.

Screening neuroimaging in neurologically asymptomatic patients with infective endocarditis

BACKGROUND AND PURPOSE

Neurological complications from infective endocarditis (IE) are common and often present with minimal clinical symptoms. In this study, we examine whether screening neuroimaging in asymptomatic patients results in increased detection of neurological complications and leads to improved patient outcomes.

METHODS

Using a database of consecutive adults with IE admitted to a single health system from 2015 to 2019, we selected patients who presented without any neurological symptoms and determined whether these patients underwent screening neuroimaging. The presence of septic emboli, territorial infarcts, intracranial hemorrhage, and mycotic aneurysms was recorded. Variables with significant differences in univariable analyses (p < .1) between those with and without screening neuroimaging were entered into regression models with age and sex to determine predictors of neurological complications and favorable discharge outcomes (modified Rankin score ≤2).

RESULTS

A total of 214 patients were included in the study, of which 154 (72%) received screening neuroimaging. Septic emboli were more common in patients who underwent screening imaging (31% vs. 15%, p = 0.02). In the first multivariate analysis, screening neuroimaging was associated with septic emboli (adjusted odds ratio [aOR] = 2.44, 95% confidence interval [CI]: [1.03-5.75], p = 0.04). In the second multivariate analysis, territorial infarcts (aOR = 0.28, 95% CI: [0.11-0.73], p = .01), but not septic emboli (aOR = 0.71, 95% CI: [0.36-1.43], p = 0.34), were associated with a favorable discharge outcome.

CONCLUSIONS

Screening neuroimaging leads to the detection of more septic emboli in IE, but only territorial infarcts (in contrast to septic emboli) correlate with an unfavorable discharge outcome.

Deconstructive repair of a traumatic vertebrovertebral arteriovenous fistula via a contralateral endovascular approach

Vertebrovertebral arteriovenous fistulas (VVAVFs) are rare entities that lack consensus guidelines for their management. Our case describes the successful treatment of a traumatic VVAVF via a contralateral deconstructive endovascular approach. A 64-year-old female presented following a traumatic fall. Computed tomography angiogram highlighted a 2 cm pseudoaneurysm of the right vertebral artery (VA) with epidural contrast enhancement and a hematoma with flow voids within the epidural space. Digital subtraction angiography showed a VVAVF at C2-3 with retrograde filling of the distal right VA. Having undergone several unsuccessful passes of the proximal dissection flap in the right VA, the patient underwent a contralateral deconstructive approach with correction of the VVAVF without complication. The remaining feeding branches had occluded after 1 week. The patient made a complete recovery without neurological sequelae at 3-month follow-up.

Cerebellar atrophy and its implications on gait in cerebral amyloid angiopathy

OBJECTIVE

Recent data suggest that cerebral amyloid angiopathy (CAA) causes haemorrhagic lesions in cerebellar cortex as well as subcortical cerebral atrophy. However, the potential effect of CAA on cerebellar tissue loss and its clinical implications have not been investigated.

METHODS

Our study included 70 non-demented patients with probable CAA, 70 age-matched healthy controls (HCs) and 70 age-matched patients with Alzheimer's disease (AD). The cerebellum was segmented into percent of cerebellar subcortical volume (pCbll-ScV) and percent of cerebellar cortical volume (pCbll-CV) represented as percent (p) of estimated total intracranial volume. We compared pCbll-ScV and pCbll-CV between patients with CAA, HCs and those with AD. Gait velocity (metres/second) was used to investigate gait function in patients with CAA.

RESULTS

Patients with CAA had significantly lower pCbll-ScV compared with both HC (1.49±0.1 vs 1.73±0.2, p<0.001) and AD (1.49±0.1 vs 1.66±0.24, p<0.001) and lower pCbll-CV compared with HCs (6.03±0.5 vs 6.23±0.6, p=0.028). Diagnosis of CAA was independently associated with lower pCbll-ScV compared with HCs (p<0.001) and patients with AD (p<0.001) in separate linear regression models adjusted for age, sex and presence of hypertension. Lower pCbll-ScV was independently associated with worse gait velocity (β=0.736, 95% CI 0.28 to 1.19, p=0.002) in a stepwise linear regression analysis including pCbll-CV along with other relevant variables.

INTERPRETATION

Patients with CAA show more subcortical cerebellar atrophy than HC or patients with AD and more cortical cerebellar atrophy than HCs. Reduced pCbll-ScV correlated with lower gait velocity in regression models including other relevant variables. Overall, this study suggests that CAA causes cerebellar injury, which might contribute to gait disturbance.

Association of Infarct Topography and Outcome After Endovascular Thrombectomy in Patients With Acute Ischemic Stroke

BACKGROUND AND OBJECTIVES

The care of patients with large vessel occlusion (LVO) stroke has been revolutionized by endovascular thrombectomy (EVT). While EVT has a large effect size, most patients treated with EVT remain disabled or die within 90 days. A better understanding of outcomes may influence EVT selection criteria, novel therapies, and prognostication. We sought to identify associations between outcomes and brain regions involved in ischemic lesions.

METHODS

For this cohort study, consecutive patients with LVO who were treated with EVT and underwent post-EVT MRI were identified from a tertiary referral center (2011-2019). Acute ischemic lesions were manually segmented from diffusion-weighted imaging and spatially normalized. Individual lesions were parcellated (atlas-defined 94 cortical regions, 14 subcortical nuclei, 20 white matter tracts) and reduced to 10 essential lesion patterns with the use of unsupervised dimensionality reduction techniques. Ninety-day modified Rankin Scale (mRS) score (>2) was modeled via bayesian regression, taking the 10 lesion patterns as inputs and controlling for lesion size, age, sex, acute NIH Stroke Scale (NIHSS) score, alteplase, prior stroke, intracerebral hemorrhage, and good reperfusion (Thrombolysis in Cerebral Infarction 2b-3). In comparative analyses, 90-day mRS score was modeled considering covariates only, and compartment-wise relevances for acute stroke severity and 90-day mRS score were evaluated.

RESULTS

There were 151 patients with LVO identified (age 68 ± 15 years, 52% female). The median NIHSS score was 16 (interquartile range 13-20); 56% had mRS score >2. Lesion locations predictive of 90-day mRS score involved bilateral but left hemispherically more pronounced precentral and postcentral gyri, insular and opercular cortex, and left putamen and caudate (area under the curve 0.91, highest probability density interval [HPDI] covering 90% certainty 0.90-0.92). The lesion location model outperformed the simpler model relying on covariates only (bayesian model comparison of 97% weight to the model with vs 3% weight to the model without lesion location). While lesions affecting subcortical nuclei had the highest relevance for stroke severity (posterior distribution mean 0.75, 90% HPDI 0.256-1.31), lesions affecting white matter tracts had the highest relevance for 90-day mRS score (0.656, 90% HPDI 0.0864-1.12).

DISCUSSION

These data describe the significance for outcomes of specific brain regions involved in ischemic lesions on MRI after EVT. Future work in additional datasets is needed to confirm these granular findings.

Abstract 69: Extent Of Tau And Its Cognitive Implications In Cerebral Amyloid Angiopathy

Background: Tau pathology is an important component of Alzheimer’s Disease but its extent and impact in cognitively healthy patients with cerebral amyloid angiopathy (CAA) are not clear. We compared in vivo tau stages estimated from the patterns of tau PET tracer uptake in patients with CAA and healthy controls (HC) and explored its relationship with amyloid burden and cognitive function in CAA.

Methods: The study included 50 cognitively healthy probable CAA patients (mean age 70±7.6) and 50 age-, sex-matched HCs (mean age 70±7.5) who underwent MRI, Pittsburgh compound B (PiB, for amyloid) and 18 F-flortaucipir (FTP, for tau) PET imaging. Mean global cortical PiB uptake was calculated. Tau stages were estimated based on the distribution pattern of cortical FTP uptake and grouped into three categories (PET Braak Staging, Figure). Within the CAA cohort, standardized z-scores of memory, processing speed and executive function testing were obtained.

Results: In the whole group, tau stages significantly correlated with age (rho=0.407, p<0.001) and global cortical PiB uptake (rho=0.554, p<0.001). Patients with CAA were more likely to exhibit more extensive tau (Stage III-VI) compared to HCs in univariate analyses (Figure, p=0.003). In a logistic regression model, more extensive tau independently associated with age (p=0.001) and PiB uptake (p<0.001) but not with the CAA diagnosis (p=0.264). Within the CAA cohort, tau stage was again independently associated with PiB uptake (p=0.002), but it did not show any association with scores of cognitive domains in univariate or multivariate models (p>0.2 for all comparisons).

Conclusion: Our results show that patients with CAA have higher PET Braak tau stages when compared to similarly aged HCs but this difference disappeared after controlling for amyloid load. Extent of tau did not correlate with cognitive scores in CAA. Overall, tau stages appear to be driven by amyloid without clinical impact in cognitively healthy CAA patients.

Abstract 157: Ischemic Strokes In Patients With Atrial Fibrillation On Oral Anticoagulant: The Neuro-AFib Study

Background: Ischemic stroke (IS) admissions in patients with atrial fibrillation (AF) using either direct oral anticoagulants (DOAC) or Vitamin K antagonists (VKA) are commonly seen in stroke units but data on their prevalence and causes are scarce. Understanding the frequency/causes of failures of current FDA-approved preventive methods in patients with AF is important to reduce stroke risk and related death/disability.

Methods: The Neuro-AFib study is a multicenter effort geared toward elucidating the causes and consequences of IS and hemorrhagic stroke in a contemporary AF cohort. Detailed clinical, laboratory and multimodal neuro- and cardiac imaging data from known AF patients consecutively admitted to 22 US academic stroke centers with an IS between 1/2018-12/2019 were used to compare characteristics of IS on vs off oral anticoagulants.

Results: Out of 6443 IS patients with AF, 4898 (76%) had known AF prior to the acute stroke. Among these patients with known AF, 2204 (45%) were using oral anticoagulants [OAC= DOAC (59.3%) or VKA (40.7%)]. Patients who had IS on OAC were younger (76.8 + 11 vs 78 + 12, p=0.001), had higher mean CHA 2 DS 2 -VASc scores (4.17 + 1.5 vs 3.9 + 1.5, p<0.0001), and more likely to have a past history of IS/TIA when compared to non-OAC group (35% vs 23%, p<0.0001). In a multivariable logistic regression model, history of IS/TIA, diabetes, hyperlipidemia, heart failure, prosthetic heart valve, sleep apnea, permanent atrial fibrillation, left atrial dilation and ischemic arterial disease were all independently associated with IS on OAC (all p<0.05). Imaging data were complete in 15% of the cohort and IS on OAC group had more acute lacunar infarcts, and extracranial and intracranial atherosclerotic disease causing 50% or more ipsilateral stenosis compared to patients with IS off OAC (all p<0.05).

Conclusions: Based on a large multicenter contemporary cohort of IS patients with known AF, the numbers of patients who failed OACs (and especially DOACs) are high. These patients have severe vascular risk factor loads, concurrent etiologies, and they are more likely to have recurrent ischemic events. Further detailed data focused on imaging and IS mechanisms from this contemporary cohort will be ready to be presented during ISC 2022.

Abstract WMP78: Microstructural Alterations And Vascular Dysfunction In Cerebral Amyloid Angiopathy

Background: Cerebral amyloid angiopathy (CAA) causes impaired vascular reactivity to physiologic stimuli that mediates CAA-related white matter hyperintensities (WMH) but its relationship to microstructural changes has not yet been tested. We hypothesized that the degree of vascular dysfunction would be associated with alterations in white matter microstructure in patients with CAA.

Methods: Fifty-five non-demented probable CAA patients underwent high-resolution structural MRI including Diffusion-Weighted Imaging (DWI) and functional MRI (fMRI). WMH volume was quantified and expressed as percent of total intracranial volume (pWMH). Vascular reactivity was measured as the amplitude of the blood-oxygenation-level-dependent response (BOLD_Amp) to a visual stimulus. Peak Width of Skeletonized Mean Diffusivity (PSMD) was calculated from DWI and used as a marker of microstructural integrity.

Results: Patients had a mean age of 69.3±7.4 years and 36 (65%) had intracerebral hemorrhage (ICH). The mean PSMD was [(3.92±0.8) х 10–4 mm2/s] and the mean BOLD_Amp was 1.15±0.2%. Neither PSMD nor BOLD_Amp differed between patients with ICH and those without (p>0.2 for all comparisons). PSMD significantly correlated with older age (r=0.335, p=0.012), with higher pWMH (r=0.792, p<0.001) and with lower BOLD_Amp (r= –0.5, p<0.001). PSMD showed a trend to increase more in patients with hypertension (HT) than without ([(4.09±0.8) х 10–4 mm2/s] vs. ([(3.74±0.8) х 10–4 mm2/s], p=0.097). BOLD_Amp also correlated with pWMH (r= –0.409, p=0.002). In a linear regression analysis, decrease in BOLD_Amp was independently associated with increased PSMD corrected for age, sex, HTN, ICH and pWMH (β= –0.91, 95%CI (–1.77)-(–0.05), p=0.037). pWMH was also associated with PSMD in this model (β=1.22, 95%CI 0.89-1.54, p<0.001).

Conclusion: This study supports the view that vascular dysfunction in CAA is closely linked with CAA-related global ischemic injury including MRI-visible white matter injury as well as microstructural tissue disruption.

Abstract WMP101: Potential Causes Of Anticoagulant Underuse In Patients With Atrial Fibrillation Presenting With Ischemic Strokes

Background: Underuse of FDA-approved stroke prevention methods in atrial fibrillation (AF) remains a major problem. We aimed to explore the potential causes of oral anticoagulant (OAC) non-use and compare the frequency of these factors between AF patients with acute ischemic stroke (AIS) off and on oral anticoagulant (OAC).

Methods: The Neuro-AFib study is a multicenter observational study aiming to clarify the causes of different stroke types in a contemporary AF cohort. Potential causes of OAC non-use were systematically collected from all enrolled patients based on the exclusion criteria of the Direct OAC (DOAC) studies. The frequency of potential causes of OAC non-use (AIS-off-OAC) are explored in AF patients consecutively admitted to 22 US academic stroke centers with an AIS between 1/2018-12/2019, and these rates are compared to AIS-on-OAC.

Results: Among 4898 patients with known AF who had IS, 2694 (55%) were not using any OAC, and 45% were AIS-on-OAC. CHA2DS2-VASc <2, the cutoff representing low embolic risk until late 2019, was found in 7% of AIS-off-OAC group compared to 3.8% in AIS-on-OAC (p<0.0001). The most common factor in OAC non-use group was history of falls (26%) vs 18% in AIS-on-OAC group (p=0.004). History of bleeding [intracranial (2.3%) and extracranial (18.5%)] was found in 20.8% of AIS-off-OAC vs 10.4% of AIS-on-OAC group (p<0.0001). 82.6% of these hemorrhages were classified as major bleeds. Pre-stroke cognitive impairment was also common in AIS-off-OAC (21.7%). Renal failure (creatinine >2mg/dl) was found in 13% of AIS-off-OAC. Gait problems leading to limited mobility (10%) and excessive alcohol use (3.8%) were other potential factors for OAC non-use. Among OAC non-users, 64% had at least one risk factor defined above.

Conclusions: In a large multicenter contemporary IS cohort with known AF, 55% of patients were not on OAC, and about two thirds of them had a reason that would exclude them from the phase 3 DOAC studies. Other than improving the accuracy of risk prediction algorithms, research should focus on identifying optimal management approaches for this large AF population who present challenges to lifelong OAC use. FDA-approved left atrial appendage closure procedures can be considered in such AF patients.

Radiomic signature of DWI-FLAIR mismatch in large vessel occlusion stroke

BACKGROUND AND PURPOSE

Ischemic diffusion-weighted imaging-fluid-attenuated inversion recovery (DWI-FLAIR) mismatch may be useful in guiding acute stroke treatment decisions given its relationship to onset time and parenchymal viability; however, it relies on subjective grading. Radiomics is an emerging image quantification methodology that may objectively represent continuous image characteristics. We propose a novel radiomics approach to characterize DWI-FLAIR mismatch.

METHODS

Ischemic lesions were visually graded for FLAIR positivity (absent, subtle, obvious) among consecutive large vessel occlusion stroke patients who underwent hyperacute MRI. Radiomic features were extracted from within the lesions on DWI and FLAIR. The DWI-FLAIR mismatch radiomics signature was built with features systematically selected by a cross-validated ElasticNet linear regression model of mismatch.

RESULTS

We identified 103 patients with mean age 68 ± 16 years; 63% were female. FLAIR hyperintensity was absent in 25%, subtle in 55%, and obvious in 20%. Inter-rater agreement for visual grading was moderate (Κ = .58). The radiomics signature of DWI-FLAIR mismatch included native FLAIR histogram kurtosis and local binary pattern-filtered FLAIR gray-level cluster shade; both correlated with visual grading (ρ = -.42, p < .001 and ρ = .40, p < .001, respectively).

CONCLUSIONS

Radiomics can describe DWI-FLAIR mismatch and may provide objective, continuous biomarkers for infarct evolution using clinical-grade images. These novel biomarkers may prove useful for treatment decisions and future research.

Lacunes, Microinfarcts, and Vascular Dysfunction in Cerebral Amyloid Angiopathy

OBJECTIVE

To analyze the relationship of lacunes with cortical cerebral microinfarcts (CMIs), to assess their association with vascular dysfunction, and to evaluate their effect on the risk of incident intracerebral hemorrhage (ICH) in cerebral amyloid angiopathy (CAA).

METHODS

The count and topography of lacunes (deep/lobar), CMIs, and white matter hyperintensity (WMH) volume were retrospectively analyzed in a prospectively enrolled CAA cohort that underwent high-resolution research MRIs. The relationship of lacunes with CMIs and other CAA-related markers including time to peak (TTP) of blood oxygen level-dependent signal, an established measure of vascular dysfunction, was evaluated in multivariate models. Adjusted Cox regression models were used to investigate the relationship between lacunes and incident ICH.

RESULTS

The cohort consisted of 122 patients with probable CAA without dementia (mean age, 69.4 ± 7.6 years). Lacunes were present in 31 patients (25.4%); all but one were located in lobar regions. Cortical CMIs were more common in patients with lacunes compared to patients without lacunes (51.6% vs 20.9%, p = 0.002). TTP was not associated with either lacunes or CMIs (both p > 0.2) but longer TTP response independently correlated with higher WMH volume (p = 0.001). Lacunes were associated with increased ICH risk in univariate and multivariate Cox regression models (p = 0.048 and p = 0.026, respectively).

CONCLUSIONS

Our findings show a high prevalence of lobar lacunes, frequently coexisting with CMIs in CAA, suggesting that these 2 lesion types may be part of a common spectrum of CAA-related infarcts. Lacunes were not related to vascular dysfunction but predicted incident ICH, favoring severe focal vessel involvement rather than global ischemia as their mechanism.

Abstract P617: Ischemic Strokes in Patients With Atrial Fibrillation: The Neuro-AFib Study

Background: An estimated 150,000 atrial fibrillation (AF) patients suffer an ischemic stroke (IS) annually in the US. Understanding the frequency/causes of underuse and failures of current FDA-approved preventive methods in patients with known AF may reduce stroke risk and related death/disability.

Methods: The Neuro-AFib study is a multicenter effort geared toward elucidating the causes and consequences of IS and hemorrhagic stroke (HS) in a contemporary AF cohort. The retrospective phase of the study is underway, aiming to obtain detailed clinical, laboratory and multimodal neuro- and cardiac imaging data from ~9,000 AF patients admitted to 30 US academic stroke centers with an IS or HS between 1/2018-12/2019. Clinical data of IS admissions from 12 sites will be discussed. Disability is defined as a modified Rankin Score (mRS) 3-5, outcomes are from the time of hospital discharge.

Results: A total of 3944 AF patients presented with an IS, mean age was 76.8 + 12, and 50.2% were female. AF was diagnosed prior to IS in 78% of patients. Data on prestroke antithrombotic usage, embolic risk scores, clinical stroke severity and outcomes are presented in the FIGURE.

Conclusions: Preliminary results from the Neuro-AFib study show high rates of underuse of approved stroke prevention measures (54%) and anticoagulant failures (46%) that result into IS even in known AF patients. Relatively high rates of pre-stroke AF detection failures were also noted (22%). Death/disability rates were high in all of these AF-related IS patients ( > 69%). Detailed data collection focused on imaging and lab markers of stroke risk from this contemporary cohort will be ready to be presented during ISC 2021.

Abstract 9: Peak Width of Skeletonized Mean Diffusivity and Cognition in Cerebral Amyloid Angiopathy

Background: We hypothesized that Peak Width of Skeletonized Mean Diffusivity (PSMD), an automated marker of cerebral microangiopathy representing microstructural disruption of white matter (WM), would be increased in patients with cerebral amyloid angiopathy (CAA) compared to healthy controls (HCs) and increased PSMD would be associated with lower processing speed scores (PSSs) in patients with CAA.

Methods: Seventy-two nondemented probable CAA patients and 23 HCs prospectively underwent high-resolution brain MRIs and cognitive tests. PSMD scores were quantified from a probabilistic skeleton of the WM tracts as previously validated (http://www.psmd-marker.com). In subjects with intracerebral hemorrhage (ICH, n=27), ICH regions were masked and removed from the PSMD pipeline. The analyses were repeated in the non-ICH hemisphere. Raw scores of Trail Making Test-B and Symbol Substitution Test were transformed into standardized z -scores and averaged to obtain PSSs.

Results: The mean age (p=0.366) and sex (p=0.811) were similar between CAA patients and HCs. PSMD was higher in the CAA group [(3.95±0.9) х 10 –4 mm 2 /s] compared to HCs [(3.32±0.6) х 10 –4 mm 2 /s] (p=0.003). This association remained significant in a linear regression model corrected for age and sex (β=0.700, 95%CI 0.3-1, p=0.001). Within the CAA cohort, higher PSMD was associated with higher WM hyperintensity volume in a multiple regression model adjusted for all relevant variables (β=0.890, 95%CI 0.7-1, p<0.001). In a regression model corrected for age, sex, years of education and presence of ICH, a lower PSS was independently associated with increased PSMD (β=-0.405, 95%CI {-0.6}-{-0.2}, p<0.001). These results did not change when the non-ICH hemisphere was used for PSMD processing.

Conclusion: PSMD is increased in CAA and is associated with worse PSSs supporting the view that disruption of white matter has a significant role in cognitive impairment in CAA.

Abstract P442: The Association of Amyloid and Tau Burden With Centrum Semiovale Perivascular Spaces in Cerebral Amyloid Angiopathy

Background: The mechanisms linking cerebral amyloid angiopathy (CAA) to enlarged perivascular spaces in centrum semiovale (CSO-EPVS) and whether other Alzheimer’s Disease (AD) pathologies might affect CSO-EPVS are unclear. We hypothesized that amyloid but not tau load would independently correlate with CSO-EPVS in CAA.

Methods: Fifty prospectively enrolled nondemented probable CAA patients underwent high-resolution structural MRI, Pittsburgh compound B (PiB, for amyloid), and 18 F-flortaucipir (FTP, for tau) PET imaging. Microbleeds (all lobar, LMB) were counted and white matter hyperintensity volume (WMH) was quantified. CSO-EPVS were counted on T 2 -MRI sequence and graded using a previously validated scale (range 0-4). A multivariate ordinal regression model was used to assess the independent associations between CSO-EPVS and mean cortical amyloid as well as tau deposition, after adjusting for relevant covariates.

Results: Patients had a mean age of 69.3±7.2. Age, sex, presence of hypertension, intracerebral hemorrhage (ICH), LMB counts, and WMH were not associated with CSO-EPVS grades (p>0.2 for all comparisons). Higher PiB uptake significantly correlated with increased CSO-EPVS (rho=0.45, p=0.001). Higher FTP showed a trend for correlation with CSO-EPVS (rho=0.26, p=0.069). In an ordinal regression model with CSO-EPVS grade as the dependent variable and both amyloid and tau levels included as predictors along with covariates presented above, the association of CSO-EPVS remained significant with higher PiB uptake (β=3.97, 95%CI 1.1-6.8, p=0.007) but not with FTP uptake (p=0.167).

Conclusion: Results of this study suggest that CSO-EPVS is independently associated with amyloid but not with tau deposition in CAA. CSO-EPVS was not associated with age or classical vascular risk factors or presence of ICH. Our results support the view that vascular amyloid but not other AD pathologies such as tau might contribute to EPVS in patients with CAA.

Abstract P474: Functional Outcomes and Regional Significance of Ischemic Lesions After Thrombectomy for Large Vessel Occlusion Stroke

Introduction: Endovascular thrombectomy (EVT) has revolutionized large vessel occlusion (LVO) stroke care. However, over half remain functionally disabled or die despite treatment. Understanding outcomes may influence EVT selection, novel therapies, and prognostication. We sought to identify associations between outcomes and brain regions involved in ischemic lesions.

Methods: For consecutive LVO patients with post-EVT MRI, acute ischemic lesions were manually segmented from DWI and spatially normalized. Individual lesion volumes were automatically parcellated (atlas-defined 94 cortical regions, 14 subcortical nuclei, 20 white matter tracts) and then reduced to ten anatomically plausible lesion patterns using unsupervised dimensionality reduction techniques. Ninety-day modified Rankin Scale (mRS) was modeled via Bayesian regression, taking the ten lesion patterns as inputs and controlling for lesion size, age, sex, acute NIH Stroke Scale, alteplase, and TICI 2b-3 reperfusion.

Results: We identified 153 LVO patients with mean age 68±15 years and 51% female. Median NIHSS was 16 (IQR 13-20), 56% received alteplase, and 84% achieved TICI2b-3. The lesion patterns predictive of 90-day mRS involved bilateral subcortical nuclei, pre- and postcentral gyri, insular and opercular cortex, as well as left-sided inferior frontal and angular gyri ( Figure 1A ). Lesions affecting white matter tracts had the highest relevance predicting 90-day mRS ( Figure 1B ).

Conclusions: These data describe the significance for outcomes of specific brain regions involved in ischemic lesions on MRI after EVT. Future work in additional datasets is needed to confirm these granular findings.

Abstract P409: Cerebellar Atrophy and Its Clinical Implications in Cerebral Amyloid Angiopathy

Background: Recent data show that cerebral amyloid angiopathy (CAA) might cause hemorrhagic lesions in cerebellar cortex as well as cerebral atrophy. However, the potential effect of CAA on cerebellar tissue loss and its clinical implications have not been investigated.

Methods: We compared cerebellar volumes in 70 nondemented patients with probable CAA to 70 age-matched healthy controls (HC) and 70 age-matched Alzheimer’s disease (AD) patients. Volumetric analyses including cerebellar cortical volume (pCbll-CV), cerebellar subcortical volume (pCbll-ScV), cerebral white matter volume (pWMV), and cerebral white matter hyperintensity volume (pWMH) were calculated as percent of total intracranial volume. Gait velocity (meters/seconds) was used to investigate the potential effect of cerebellar tissue loss on gait function.

Results: Patients with CAA had significantly lower pCbll-ScV and pCbll-CV compared to HC (1.49%±0.17 vs 1.71%±0.23, p<0.001 and 6.03%±0.50 vs 6.23%±0.56, p<0.027 respectively). When compared to AD, pCbll-ScV but not pCbll-CV was significantly lower in CAA (1.49%±0.17 vs 1.670.24, p<0.001). Diagnosis of CAA was independently associated with lower pCbll-ScV in a general linear model adjusting for age, sex and presence of hypertension when compared to both HCs and patients with AD (p<0.0001 for all associations, after Bonferroni correction for multiple comparisons). Lower pCbll-ScV was associated with lower gait velocity score in univariate and multivariate analysis adjusted for relevant variables (adjusted β=0.826, 95%CI 0.357-1.295, p=0.001).

Conclusion: Patients with CAA show cerebellar atrophy; predominantly in the subcortical cerebellum when compared to both HC and AD patients. Cerebellar tissue loss independently correlated with worse gait function in CAA patients. Overall, this study supports the view that CAA causes cerebellar injury which might mediate gait disturbance in patients with CAA.

Abstract 38: Hemorrhagic Strokes in Patients With Atrial Fibrillation: The Neuro-AFib Study

Background: We aimed to compare the clinical features and short-term outcomes of hemorrhagic stroke (HS) to ischemic stroke (IS) in atrial fibrillation (AF) patients using a large contemporary cohort.

Methods: The Neuro-AFib study is a multicenter effort to elucidate the current causes and consequences of IS and HS in AF patients. The retrospective phase of the study is underway, aimed at obtaining detailed clinical, laboratory and multimodal neuro- and cardiac imaging data from ~9,000 patients with AF admitted to 30 academic stroke centers in the US with an IS or HS between 1/2018-12/2019. Preliminary clinical data from 12 sites are presented in this abstract.

Results: Of 4764 stroke admissions with AF, 820 (17.2%) had HS and 3944 IS. Patients with HS were younger (74.8 + 12 vs 76.8 + 12), more likely to be male (54% vs 46%) and had lower CHA 2 DS 2 -VASC (3.6 + 1.6 vs 3.9 + 1.6) than IS [all p<0.05]. Patients with HS were more likely to be on AC compared to IS (60% vs 38%, p<0.001). Within the HS cohort, 32% were on direct oral anticoagulant, 28% on warfarin, 16% on antiplatelet, and 24% on no antithrombotic. Patients with HS had worse outcomes than IS in terms of in hospital case fatality (32.4 vs 10.3%, p<0.001) and severe disability (modified Rankin Scale 4-5) at discharge (63.3% vs 53.7%, p=0.002) despite similar rates of severe disability before admission (7% vs 6.2%, p=0.73). All of the reported associations remained significant after adjustment for age, sex and other relevant covariates.

Conclusions: Preliminary findings from the Neuro-AFib study show significantly worse outcomes for HS compared to IS in AF patients, with triple case fatality and elevated severe disability risks. These results showcase the importance of identifying AF patients at high HS risk. Detailed imaging markers of HS risk including microbleeds, superficial siderosis, leukoaraiosis within the full cohort will be analyzed and discussed during ISC 2021.

Abstract P315: Radiomics Signature of DWI-FLAIR Mismatch Correlates With Clinical Phenotype of Patients With Large Vessel Occlusion Stroke

Introduction: For patients presenting with large vessel occlusion for endovascular thrombectomy (EVT), FLAIR hyperintensity within ischemic lesions may be inversely related to parenchymal viability but relies on subjective grading. Radiomics is an emerging image quantification methodology that may more objectively represent continuous image characteristics. We propose a novel radiomics approach to describe infarct FLAIR positivity and evaluate its correlation with clinical presentation.

Methods: For patients with pre-EVT MRI, ischemic lesions were manually segmented on DWI, co-registered to FLAIR and visually graded for FLAIR positivity (0, +, ++). Radiomics were extracted within the ischemic lesion outlines on FLAIR. LASSO regression was used to select features for the DWI-FLAIR mismatch radiomics signature. Canonical correlation analysis was used to relate this signature to clinical features.

Results: We identified 103 patients with mean age 68±16 years and 63% female. The radiomics signature of DWI-FLAIR mismatch included FLAIR histogram kurtosis and gray level cluster shade; both correlated with visual grading ( Figure 1A ). The first of the estimated 3 canonical pairs was statistically significant (canonical correlation=0.50, corrected p=0.009); kurtosis was positively associated with atrial fibrillation and age, while negatively associated with last known well, smoking, and diabetes ( Figure 1B ).

Conclusion: The radiomics signature of DWI-FLAIR mismatch before EVT correlates with visual grading and may provide a continuous metric to describe infarct evolution. Further exploration of larger datasets is required to determine additional granular relationships with clinical features.

Endovascular treatment of a ruptured posterior fossa pure arterial malformation: illustrative case

BACKGROUND

Pure arterial malformations (PAMs) are rare vascular anomalies that are commonly mistaken for other vascular malformations. Because of their purported benign natural history, PAMs are often conservatively managed. The authors report the case of a ruptured PAM leading to subarachnoid hemorrhage (SAH) with intraventricular extension that was treated endovascularly.

OBSERVATIONS

A 38-year-old man presented with a 1-day history of headaches and nausea. A computed tomography scan demonstrated diffuse SAH with intraventricular extension, and angiography revealed a right posterior inferior cerebellar artery-associated PAM. The PAM was treated with endovascular Onyx embolization.

LESSONS

To the authors' knowledge, only 2 other cases of SAH associated with PAM have been reported. In those 2 cases, surgical clipping was pursued for definitive treatment. Here, the authors report the first case of a ruptured PAM treated using an endovascular approach, showing its feasibility as a treatment option particularly in patients in whom open surgery is too high a risk.

Infarct Growth despite Endovascular Thrombectomy Recanalization in Large Vessel Occlusive Stroke

BACKGROUND AND PURPOSE

Endovascular thrombectomy (EVT) has revolutionized large vessel occlusion stroke care. However, not all patients with good endovascular results achieve good outcomes. We sought to understand the clinical significance of magnetic resonance imaging defined infarct growth despite adequate reperfusion and identify associated clinical and radiographic variables.

METHODS

History, presentation, treatments, and outcomes for consecutive EVT patients at a referral center were collected. Adequate reperfusion was defined as thrombolysis in cerebral infarction (TICI) score 2b-3. Region-specific infarct volumes in white matter, cortex, and basal ganglia were determined on diffusion-weighted imaging. Infarct growth was defined as post-EVT minus pre-EVT volume. Good outcome was defined as 90-day modified Rankin Scale ≤2.

RESULTS

Forty-four patients with adequate reperfusion were identified with median age 72 years; 64% were women. Each region showed infarct growth: white matter (median pre-EVT 7 cubic centimeters [cc], post-EVT 16 cc), cortex (4 cc, 15 cc), basal ganglia (2 cc, 4 cc), total (20 cc, 39 cc). In multivariable regression, total infarct growth independently decreased the odds of good outcome (odds ratio = .946, 95% CI = .897, .998). Further multivariable analyses for determinants of infarct growth identified female sex was associated with less total growth (β = -.294, P = .042), TICI 3 was associated with less white matter growth (β = -.277, P = .048) and cortical growth (β = -.335, P = .017), and both female sex (β = -.332, P = .015) and coronary disease (β = -.337, P = .015) were associated with less cortical growth.

CONCLUSIONS

Infarct growth occurred despite adequate reperfusion, disproportionately in the cortex, and independently decreased the odds of good outcome. Infarct growth occurred while patients were hospitalized and may represent a therapeutic target. Potential determinants of region-specific infarct growth were identified that require confirmation in larger studies.

White Matter Acute Infarct Volume After Thrombectomy for Anterior Circulation Large Vessel Occlusion Stroke is Associated with Long Term Outcomes

OBJECTIVES

Despite the proven efficacy of endovascular thrombectomy (EVT) for large vessel occlusion stroke, over half treated remain functionally disabled or die. Infarct topography may have implications for prognostication, patient selection, and the development of tissue-specific neuroprotective agents. We sought to quantify white matter injury in anterior circulation acute infarcts post-EVT to understand its significance and identify its determinants.

MATERIALS AND METHODS

Demographics, history, presentations, and outcomes for consecutive patients treated with EVT were recorded in a prospectively maintained database at a single center. Acute infarct masks were coregistered to standard space. Standard atlases of white matter, cortex, and basal ganglia were used to determine region-specific infarct volumes.

RESULTS

167 individuals were identified with median age 69 years and 53% women. 85% achieved adequate reperfusion (TICI 2b-3) after EVT; 43% achieved 90-day functional independence (mRS 0-2). Median infarct volumes were 45cc (IQR 18-122) for total, 17cc (6-49) for white matter, 21cc (4-53) for cortex, and 5cc (1-8) for basal ganglia. The odds of 90-day mRS 0-2 were reduced in patients with larger white matter infarct volume (cc, OR=0.89, 95%CI=0.81-0.96), independent of cortex infarct volume, basal ganglia infarct volume, age, NIHSS, and TICI 2b-3 reperfusion. Reperfusion-to-MRI time was associated with white matter infarct volume (hr, β=0.119, p=0.017), but not cortical or basal ganglia infarct volume.

CONCLUSIONS

These data quantitatively describe region-specific infarct volumes after EVT and suggest the clinical relevance of white matter infarct volume as a predictor of long-term outcomes. Further study is warranted to examine delayed white matter infarction and the significance of specific white matter tracts.

Diffuse Cerebral Edema After Moyamoya Disease-Related Intracerebral Hemorrhage: A Case Report

Moyamoya disease (MMD) is a rare, progressive occlusive disease characterized by bilateral internal carotid artery hypoplasia that often presents with ischemic stroke and intracerebral hemorrhage (ICH). Although MMD-related ICH is generally managed similarly to spontaneous ICH, we present a case in which standard management strategies may have led to an unprecedented devastating outcome. A 37-year-old female without any previous medical history presented with headache and right-sided weakness. A computed tomography (CT) scan revealed a large left basal ganglia ICH. Vessel imaging revealed diffuse narrowing of the entire anterior circulation with prominent leptomeningeal collaterals consistent with MMD. The patient's systolic blood pressure was kept under 140 mmHg. During the hospitalization, she became hypocarbic while being trialed on pressure support ventilation. Several hours later, she developed fixed and dilated pupils. Repeat CT head showed new diffuse cerebral edema with tonsillar herniation. Despite hyperosmolar therapy, paralytics, pentobarbital, and cerebrospinal fluid diversion, no improvement was noted. Unfortunately, brain MRI revealed multifocal brainstem infarcts with superimposed Duret hemorrhages. Herein, we report diffuse cerebral edema as a complication of MMD-related ICH. We hypothesize that disruptions of delicate cerebral autoregulatory mechanisms led to extensive hypoxic-ischemic injury. In the setting of ICH, aggressive blood pressure management coupled with relative hypocapnia may have likely caused vasoconstriction of poorly compliant arteries leading to worsened cerebral blood flow and ischemia. Therefore, because of its complex pathophysiology, strict adherence to eucapnia should be maintained in MMD-related ICH.

Spontaneous hemorrhage after external ventricular drain placement in the setting of low factor VII secondary to liver cirrhosis

Background:

Alterations in normal coagulation and hemostasis are critical issues that require special attention in the neurosurgical patient. These disorders pose unique challenges in the management of these patients who often have concurrent acute ischemic and hemorrhagic injuries. Although neurosurgical intervention in such cases may be unavoidable and potentially life-saving, these patients should be closely observed after instrumentation.

Case Description:

A 57-year-old male with liver cirrhosis secondary to amyloid light-chain amyloidosis was admitted to the intensive care unit for the management of delayed hydrocephalus. An external ventricular drain (EVD) was placed for the treatment and monitoring of hydrocephalus. Five days after EVD placement, a head computed tomography scan revealed a tract hemorrhage. However, on repeated imaging, the size of the hemorrhage continued to increase despite aggressive blood pressure control and several doses of phytonadione. Extensive coagulopathy workup was remarkable for low factor VII levels. In that setting, recombinant activated factor VII was administered to normalize factor VII levels, and the tract hemorrhage stabilized.

Conclusion:

To the best of our knowledge, this is the first case of spontaneous hemorrhage after EVD placement in the setting of liver cirrhosis-associated factor VII deficiency. Our case highlights the importance of identifying coagulation disorders in neurosurgical patients at high risk for coagulopathy and closely monitoring them postoperatively.

Toward a more inclusive paradigm: thrombectomy for stroke patients with pre-existing disabilities

BACKGROUND

Persons with pre-existing disabilities represent over one-third of acute stroke presentations, but account for a far smaller proportion of those receiving endovascular thrombectomy (EVT) and thrombolysis. This is despite existing ethical, economic, legal, and social directives to maximize equity for this vulnerable population. We sought to determine associations between baseline modified Rankin Scale (mRS) and outcomes after EVT.

METHODS

Individuals who underwent EVT were identified from a prospectively maintained database. Demographics, medical history, presentations, treatments, and outcomes were recorded. Baseline disability was defined as baseline mRS≥2. Accumulated disability was defined as the delta between baseline mRS and absolute 90-day mRS.

RESULTS

Of 381 individuals, 49 had baseline disability (five with mRS=4, 23 mRS=3, 21 mRS=2). Those with baseline disability were older (81 vs 68 years, P<0.0001), more likely female (65% vs 49%, P=0.032), had more coronary disease (39% vs 20%, P=0.006), stroke/TIA history (35% vs 15%, P=0.002), and higher NIH Stroke Scale (19 vs 16, P=0.001). Baseline mRS was associated with absolute 90-day mRS ≤2 (OR=0.509, 95%CI=0.370-0.700). However, baseline mRS bore no association with accumulated disability by delta mRS ≤0 (ie, return to baseline, OR=1.247, 95%CI=0.943-1.648), delta mRS ≤1 (OR=1.149, 95%CI=0.906-1.458), delta mRS ≤2 (OR 1.097, 95% CI 0.869-1.386), TICI 2b-3 reperfusion (OR=0.914, 95%CI=0.712-1.173), final infarct size (P=0.853, β=-0.014), or intracerebral hemorrhage (OR=0.521, 95%CI=0.244-1.112).

CONCLUSIONS

While baseline mRS was associated with absolute 90-day disability, there was no association with accumulated disability or other outcomes. Patients with baseline disability should not be routinely excluded from EVT based on baseline mRS alone.

Association Between Immunosuppressive Treatment and Outcomes of Cerebral Amyloid Angiopathy-Related Inflammation

IMPORTANCE

Cerebral amyloid angiopathy-related inflammation (CAA-ri), a distinct subtype of cerebral amyloid angiopathy, is characterized by an autoimmune reaction to cerebrovascular β-amyloid deposits. Outcomes and response to immunosuppressive therapy for CAA-ri are poorly understood.

OBJECTIVE

To identify clinical, neuroimaging, laboratory, pathologic, or treatment-related associations with outcomes after an episode of CAA-ri.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study of prospectively identified individuals who presented from July 3, 1998, to November 27, 2017, with a median follow-up of 2.7 years (interquartile range, 1.0-5.5 years). The study included 48 consecutive patients with CAA-ri meeting diagnostic criteria who had at least 1 disease episode and subsequent outcome data. No patients refused or were excluded.

EXPOSURES

Prespecified candidate variables were immunosuppressive therapies, cerebrospinal fluid pleocytosis, magnetic resonance imaging findings of recent infarcts or contrast enhancement, and histopathologic evidence of vessel wall inflammation.

MAIN OUTCOMES AND MEASURES

Clinical improvement and worsening were defined by persistent changes in signs or symptoms, radiographic improvement by decreased subcortical foci of T2 hyperintensity or T1 enhancement, and radiographic worsening by increased subcortical T2 hyperintensity, T1 enhancement, or infarcts. Disease recurrence was defined as new-onset clinical symptoms associated with new imaging findings.

RESULTS

The 48 individuals in the study included 29 women and had a mean (SD) age of 68.9 (9.9) years. Results of presenting magnetic resonance imaging revealed that 10 of 29 patients with CAA-ri (34%) had T1 contrast enhancement, 30 of 32 (94%) had subcortical T2 hyperintensity (22 of 30 [73%] asymmetric), 7 of 32 (22%) had acute or subacute punctate infarcts, and 27 of 31 (87%) had microbleeds. Immunosuppressive treatments after first episodes included corticosteroids (33 [69%]), cyclophosphamide (6 [13%]), and mycophenolate (2 [4%]); 14 patients (29%) received no treatment. Clinical improvement and radiographic improvement were each more likely in individuals treated with an immunosuppressive agent than with no treatment (clinical improvement: 32 of 34 [94%] vs 7 of 14 [50%]; odds ratio, 16.0; 95% CI, 2.72-94.1; radiographic improvement: 24 of 28 [86%] vs 4 of 14 [29%]; odds ratio, 15.0; 95% CI, 3.12-72.1). Recurrence was less likely if CAA-ri was treated with any immunosuppressant agent than not (9 of 34 [26%] vs 10 of 14 [71%]; hazard ratio, 0.19; 95% CI, 0.07-0.48). When controlling for treatment, no variables were associated with outcomes aside from an association between APOE ɛ4 and radiographic improvement (odds ratio, 4.49; 95% CI, 1.11-18.2).

CONCLUSIONS AND RELEVANCE

These results from a relatively large series of patients with CAA-ri support the effectiveness of immunosuppressive treatment and suggest that early treatment may both improve the initial disease course and reduce the likelihood of recurrence. These results raise the possibility that early blunting of CAA-ri and the autoimmune response may have long-term benefits for the subsequent disease course.

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 (β = .202, P < .001).

CONCLUSIONS

MES may help to risk stratify patients as their presence is associated with ischemic recurrence and worse outcomes.