An Exploratory Analysis of Preclinical and Clinical Factors Associated With Sleep Disturbance Assessed via the Neuro-QoL After Hemorrhagic Stroke

Background and Purpose

Sleep disturbance after hemorrhagic stroke (intracerebral or subarachnoid hemorrhage) can impact rehabilitation, recovery, and quality of life. We sought to explore preclinical and clinical factors associated with sleep disturbance after hemorrhagic stroke assessed via the Quality of Life in Neurological Disorders (Neuro-QoL) short form sleep disturbance inventory.

Methods

We telephonically completed the Neuro-QoL short form sleep disturbance inventory 3-months and 12-months after hemorrhagic stroke for patients >18-years-old hospitalized between January 2015 and February 2021. We examined the relationship between sleep disturbance (T-score >50) and social and neuropsychiatric history, systemic and neurological illness severity, medical complications, and temporality.

Results

The inventory was completed for 70 patients at 3-months and 39 patients at 12-months; 18 (26%) had sleep disturbance at 3-months and 11 (28%) had sleep disturbance at 12-months. There was moderate agreement (κ = .414) between sleep disturbance at 3-months and 12-months. Sleep disturbance at 3-months was related to unemployment/retirement prior to admission (P = .043), lower Glasgow Coma Scale score on admission (P = .021), higher NIHSS score on admission (P = .041) and infection while hospitalized (P = .036). On multivariate analysis, sleep disturbance at 3-months was related to unemployment/retirement prior to admission (OR 3.58 (95% CI 1.03-12.37), P = .044). Sleep disturbance at 12-months was related to premorbid mRS score (P = .046).

Conclusion

This exploratory analysis did not demonstrate a sustained relationship between any preclinical or clinical factors and sleep disturbance after hemorrhagic stroke. Larger studies that include comparison to patients with ischemic stroke and healthy individuals and utilize additional techniques to evaluate sleep disturbance are needed.

Optimal medical therapy is lacking in patients undergoing intervention for symptomatic carotid artery stenosis and protects against larger areas of cerebral infarction

OBJECTIVES

Carotid interventions are indicated for both patients with symptomatic and a subset of patients with severe asymptomatic carotid artery stenosis (CAS). Symptomatic CAS accounts for up to 12%-25% of overall carotid interventions, but predictors of symptomatic presentation remain poorly defined. The aim of this study was to identify factors associated with symptomatic CAS in our patient population.

METHODS

Between January 2015 and February 2022, an institutional retrospective cohort study of prospectively collected data on patients undergoing interventions for CAS was performed. Procedures included carotid endarterectomy (CEA), transcarotid artery revascularization (TCAR), and transfemoral carotid artery stenting (TF-CAS). Demographic data, comorbidities, procedural details, and anatomic features from various imaging modalities were collected. Comparisons were made between symptomatic (symptoms within the prior 6 months) and asymptomatic patients.

RESULTS

During the study period, 279 patients who underwent intervention for symptomatic CAS were paired with a randomly selected cohort of 300 patients who underwent intervention for asymptomatic CAS from a total patient cohort of 1143 patients undergoing interventions for asymptomatic CAS. Demographic data did not differ between groups. Patients with symptomatic CAS more frequently had prior TIA/stroke (>6 months remote to the current event), but less frequently had coronary artery disease or chronic kidney disease and were less likely to receive adequate medical management including antihypertensive agents, lipid-lowering agents, and anti-platelet therapy. On multivariate analysis, remote prior TIA/stroke and lack of anti-platelet therapy remained significant. Among symptomatic patients presenting with stroke, lack of anti-platelet therapy was associated with an overall larger area of parenchymal involvement. No difference was observed with single versus dual anti-platelet therapy. Furthermore, symptomatic patients were more likely to have ulcerated plaques (30.9% vs 18%, p < .001), and symptomatic patients with ulcerated plaques more frequently had less than 50% compared to moderate/severe CAS. Nine patients who presented with symptoms had mild CAS and underwent intervention.

CONCLUSIONS

Symptomatic CAS was associated with a history of remote prior symptoms and lack of anti-platelet therapy at time of presentation. Furthermore, symptomatic patients not on anti-platelet agents were more likely to have a greater area of parenchymal involvement when presenting with stroke and symptomatic patients with ulcerated plaques were more likely to have mild CAS, suggesting the role of plaque instability in symptomatic presentation. These findings underscore the importance of appropriate medical management and adherence in all patients with CAS and perhaps a role for more frequent surveillance in those with potentially unstable plaque morphology.

Relationship Between Hemorrhage Type and Development of Emotional and Behavioral Dyscontrol After Hemorrhagic Stroke

OBJECTIVE

Emotional and behavioral dyscontrol (EBD), a neuropsychiatric complication of stroke, leads to patient and caregiver distress and challenges to rehabilitation. Studies of neuropsychiatric sequelae in stroke are heavily weighted toward ischemic stroke. This study was designed to compare risk of EBD following intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) and to identify risk factors for EBD following hemorrhagic stroke.

METHODS

The authors conducted a prospective cohort study of patients hospitalized for nontraumatic hemorrhagic stroke between 2015 and 2021. Patients or legally authorized representatives completed the Quality of Life in Neurological Disorders (Neuro-QOL) EBD short-form inventory 3 months after hospitalization. Univariable and multivariable analyses identified risk factors for EBD after hemorrhagic stroke.

RESULTS

The incidence of EBD was 21% (N=15 of 72 patients) at 3 months after hemorrhagic stroke. Patients with ICH were more likely to develop EBD; 93% of patients with EBD (N=14 of 15) had ICH compared with 56% of patients without EBD (N=32 of 57). The median Glasgow Coma Scale (GCS) score at hospital admission was lower among patients who developed EBD (13 vs. 15 among those without EBD). Similarly, admission scores on the National Institutes of Health Stroke Scale (NIHSS) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) were higher among patients with EBD (median NIHSS score: 7 vs. 2; median APACHE II score: 17 vs. 11). Multivariable analyses identified hemorrhage type (ICH) and poor admission GCS score as predictors of EBD 3 months after hemorrhagic stroke.

CONCLUSIONS

Patients with ICH and a low GCS score at admission are at increased risk of developing EBD 3 months after hemorrhagic stroke and may benefit from early intervention.

Using strain to uncover the interplay between two- and three-dimensional charge density waves in high-temperature superconducting YBa2Cu3Oy

Uniaxial pressure provides an efficient approach to control charge density waves in YBa2Cu3Oy. It can enhance the correlation volume of ubiquitous short-range two-dimensional charge-density-wave correlations, and induces a long-range three-dimensional charge density wave, otherwise only accessible at large magnetic fields. Here, we use x-ray diffraction to study the strain dependence of these charge density waves and uncover direct evidence for a form of competition between them. We show that this interplay is qualitatively described by including strain effects in a nonlinear sigma model of competing superconducting and charge-density-wave orders. Our analysis suggests that strain stabilizes the 3D charge density wave in the regions between disorder-pinned domains of 2D charge density waves, and that the two orders compete at the boundaries of these domains. No signatures of discommensurations nor of pair density waves are observed. From a broader perspective, our results underscore the potential of strain tuning as a powerful tool for probing competing orders in quantum materials.

Association of Neighborhood Socioeconomic Status With Withdrawal of Life-Sustaining Therapies After Intracerebral Hemorrhage

BACKGROUND AND OBJECTIVES

Mortality after intracerebral hemorrhage (ICH) is common. Neighborhood socioeconomic status (nSES) is an important social determinant of health (SDoH) that can affect clinical outcome. We hypothesize that SDoH, including nSES, contribute to differences in withdrawal of life-sustaining therapies (WLSTs) and mortality in patients with ICH.

METHODS

We performed a retrospective study of patients with ICH at 3 tertiary care hospitals between January 2017 and December 2022 identified through the Get with the Guidelines Database. We collected data on age, clinical severity, race/ethnicity, median household income, insurance, marital status, religion, mortality before discharge, and WLST from the electronic medical record. We assessed for associations between SDoH and WLST, mortality, and poor discharge mRS using Mann-Whitney U tests and χ2 tests. We performed multivariable analysis using backward stepwise logistic regression.

RESULTS

We identified 868 patients (median age 67 [interquartile range (IQR) 55-78] years; 43% female) with ICH. Of them, 16% were Black non-Hispanic, 17% were Asian, and 15% were of Hispanic ethnicity; 50% were on Medicare and 22% on Medicaid, and the median (IQR) household income was $81,857 ($58,669-$122,078). Mortality occurred in 17% of patients, and of them, 84% of patients had WLST. Patients from zip codes with higher median household incomes had higher incidence of WLST and mortality (p < 0.01). Black non-Hispanic race was associated with lower WLST and discharge mortality (p ≤ 0.01 for both). In multivariable analysis adjusting for age and clinical severity scores, patients who lived in zip codes with high-income levels were more likely to have WLST (adjusted odds ratio [aOR] 1.88; 95% CI 1.29-2.74) and mortality before discharge (aOR 1.5; 95% CI 1.06-2.13).

DISCUSSION

SDoH, including nSES, are associated with WLST after ICH. This has important implications for the care and management of patients with ICH.

Use of Carotid Web Angioarchitecture for Stroke Risk Assessment

OBJECTIVE

To examine the usefulness of carotid web (CW), carotid bifurcation and their combined angioarchitectural measurements in assessing stroke risk.

METHODS

Anatomic data on the internal carotid artery (ICA), common carotid artery (CCA), and the CW were gathered as part of a retrospective study from symptomatic (stroke) and asymptomatic (nonstroke) patients with CW. We built a model of stroke risk using principal-component analysis, Firth regression trained with 5-fold cross-validation, and heuristic binary cutoffs based on the Minimal Description Length principle.

RESULTS

The study included 22 patients, with a mean age of 55.9 ± 12.8 years; 72.9% were female. Eleven patients experienced an ischemic stroke. The first 2 principal components distinguished between patients with stroke and patients without stroke. The model showed that ICA-pouch tip angle (P = 0.036), CCA-pouch tip angle (P = 0.036), ICA web-pouch angle (P = 0.036), and CCA web-pouch angle (P = 0.036) are the most important features associated with stroke risk. Conversely, CCA and ICA anatomy (diameter and angle) were not found to be risk factors.

CONCLUSIONS

This pilot study shows that using data from computed tomography angiography, carotid bifurcation, and CW angioarchitecture may be used to assess stroke risk, allowing physicians to tailor care for each patient according to risk stratification.

Longitudinal Spin Fluctuations Driving Field-Reinforced Superconductivity in UTe_{2}

Our measurements of ^{125}Te NMR relaxations reveal an enhancement of electronic spin fluctuations above μ_{0}H^{*}∼15  T, leading to their divergence in the vicinity of the metamagnetic transition at μ_{0}H_{m}≈35  T, below which field-reinforced superconductivity appears when a magnetic field (H) is applied along the crystallographic b axis. The NMR data evidence that these fluctuations are dominantly longitudinal, providing a key to understanding the peculiar superconducting phase diagram in H∥b, where such fluctuations enhance the pairing interactions.

Diaschisis Profiles in the Cerebellar Response to Hemodynamic Stimuli: Insights From Dynamic Measurement of Cerebrovascular Reactivity to Identify Occult and Transient Maxima

BACKGROUND

Crossed cerebellar diaschisis (CCD) refers to depressions in perfusion and metabolism within the cerebellar hemisphere contralateral to supratentorial disease. Prior investigation into CCD in cerebrovascular reactivity (CVR) has been limited to terminal CVR estimations (CVRend ). We recently have demonstrated the presence of unsustained CVR maxima (CVRmax ) using dynamic CVR analysis, offering a fully dynamic characterization of CVR to hemodynamic stimuli.

PURPOSE

To investigate CCD in CVRmax from dynamic blood oxygen level-dependent (BOLD) MRI, by comparison with conventional CVRend estimation.

STUDY TYPE

Retrospective.

POPULATION

A total of 23 patients (median age: 51 years, 10 females) with unilateral chronic steno-occlusive cerebrovascular disease, without prior knowledge of CCD status.

FIELD STRENGTH/SEQUENCE

A 3-T, T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE) and acetazolamide-augmented BOLD imaging performed with a gradient-echo echo-planar imaging (EPI) sequence.

ASSESSMENT

A custom denoising pipeline was used to generate BOLD-CVR time signals. CVRend was established using the last minute of the BOLD response relative to the first-minute baseline. Following classification of healthy versus diseased cerebral hemispheres, CVRmax and CVRend were calculated for bilateral cerebral and cerebellar hemispheres. Three independent observers evaluated all data for the presence of CCD.

STATISTICAL TESTS

Pearson correlations for comparing CVR across hemispheres, two-proportion Z-tests for comparing CCD prevalence, and Wilcoxon signed-rank tests for comparing median CVR. The level of statistical significance was set at P ≤ 0.05.

RESULTS

CCD-related changes were observed on both CVRend and CVRmax maps, with all CCD+ cases identifiable by inspection of either map. Diseased cerebral and contralateral cerebellar hemispheric CVR correlations in CCD+ patients were stronger when using CVRend (r = 0.728) as compared to CVRmax (r = 0.676). CVR correlations between healthy cerebral hemispheres and contralateral cerebellar hemispheres were stronger for CVRmax (r = 0.739) than for CVRend (r = 0.705).

DATA CONCLUSION

CCD-related alterations could be observed in CVR examinations. Conventional CVRend may underestimate CVR and could exaggerate CCD.

EVIDENCE LEVEL

4.

TECHNICAL EFFICACY

Stage 3.

Giant lattice softening at a Lifshitz transition in Sr2RuO4

The interplay of electronic and structural degrees of freedom in solids is a topic of intense research. More than 60 years ago, Lifshitz discussed a counterintuitive possibility: lattice softening driven by conduction electrons at topological Fermi surface transitions. The effect that he predicted, however, was small and has not been convincingly observed. Using a piezo-based uniaxial pressure cell to tune the ultraclean metal strontium ruthenate while measuring the stress-strain relationship, we reveal a huge softening of the Young's modulus at a Lifshitz transition of a two-dimensional Fermi surface and show that it is indeed driven entirely by the conduction electrons of the relevant energy band.

Factors Associated With Anxiety After Hemorrhagic Stroke

OBJECTIVE

A significant number of patients develop anxiety after stroke. The objective of this study was to identify risk factors for anxiety after hemorrhagic stroke that may facilitate diagnosis and treatment.

METHODS

Patients admitted between January 2015 and February 2021 with nontraumatic hemorrhagic stroke (intracerebral [ICH] or subarachnoid [SAH] hemorrhage) were assessed telephonically 3 and 12 months after stroke with the Quality of Life in Neurological Disorders Anxiety Short Form to evaluate the relationships between poststroke anxiety (T score >50) and preclinical social and neuropsychiatric history, systemic and neurological illness severity, and in-hospital complications.

RESULTS

Of 71 patients who completed the 3-month assessment, 28 (39%) had anxiety. There was a difference in Glasgow Coma Scale (GCS) scores on admission between patients with anxiety (median=14, interquartile range [IQR]=12-15) and those without anxiety (median=15, IQR=14-15) (p=0.034), and the incidence of anxiety was higher among patients with ICH (50%) than among those with SAH (20%) (p=0.021). Among patients with ICH, anxiety was associated with larger median ICH volume (25 cc [IQR=8-46] versus 8 cc [IQR=3-13], p=0.021) and higher median ICH score (2 [IQR=1-3] versus 1 [IQR=0-1], p=0.037). On multivariable analysis with GCS score, hemorrhage type, and neuropsychiatric history, only hemorrhage type remained significant (odds ratio=3.77, 95% CI=1.19-12.05, p=0.024). Of the 39 patients who completed the 12-month assessment, 12 (31%) had anxiety, and there was a difference in mean National Institutes of Health Stroke Scale scores between patients with (5 [IQR=3-12]) and without (2 [IQR=0-4]) anxiety (p=0.045). There was fair agreement (κ=0.38) between the presence of anxiety at 3 and 12 months.

CONCLUSIONS

Hemorrhage characteristics and factors assessed with neurological examination on admission are associated with the development of poststroke anxiety.

Sub-1.4 cm3 capsule for detecting labile inflammatory biomarkers in situ

Transient molecules in the gastrointestinal tract such as nitric oxide and hydrogen sulfide are key signals and mediators of inflammation. Owing to their highly reactive nature and extremely short lifetime in the body, these molecules are difficult to detect. Here we develop a miniaturized device that integrates genetically engineered probiotic biosensors with a custom-designed photodetector and readout chip to track these molecules in the gastrointestinal tract. Leveraging the molecular specificity of living sensors1, we genetically encoded bacteria to respond to inflammation-associated molecules by producing luminescence. Low-power electronic readout circuits2 integrated into the device convert the light emitted by the encapsulated bacteria to a wireless signal. We demonstrate in vivo biosensor monitoring in the gastrointestinal tract of small and large animal models and the integration of all components into a sub-1.4 cm3 form factor that is compatible with ingestion and capable of supporting wireless communication. With this device, diseases such as inflammatory bowel disease could be diagnosed earlier than is currently possible, and disease progression could be more accurately tracked. The wireless detection of short-lived, disease-associated molecules with our device could also support timely communication between patients and caregivers, as well as remote personalized care.

Expanded quantum vortex liquid regimes in the electron nematic superconductors FeSe1-xSx and FeSe1-xTex

The quantum vortex liquid (QVL) is an intriguing state of type-II superconductors in which intense quantum fluctuations of the superconducting (SC) order parameter destroy the Abrikosov lattice even at very low temperatures. Such a state has only rarely been observed, however, and remains poorly understood. One of the key questions is the precise origin of such intense quantum fluctuations and the role of nearby non-SC phases or quantum critical points in amplifying these effects. Here we report a high-field magnetotransport study of FeSe_1-xS_x and FeSe_1-xTe_x which show a broad QVL regime both within and beyond their respective electron nematic phases. A clear correlation is found between the extent of the QVL and the strength of the superconductivity. This comparative study enables us to identify the essential elements that promote the QVL regime in unconventional superconductors and to demonstrate that the QVL regime itself is most extended wherever superconductivity is weakest.

White Matter Cerebrovascular Reactivity: Effects of Microangiopathy and Proximal Occlusions on the Dynamic BOLD Response

Introduction

Cerebral microangiopathy often manifests as white matter hyperintensities (WMH) on T2-weighted MR images and is associated with elevated stroke risk. Large vessel steno-occlusive disease (SOD) is also independently associated with stroke risk, however, the interaction of microangiopathy and SOD is not well understood. Cerebrovascular reactivity (CVR) describes the capacity of cerebral circulation to adapt to changes in perfusion pressure and neurovascular demand, and its impairment portends future infarctions. CVR can be measured with blood oxygen level dependent (BOLD) imaging following acetazolamide stimulus (ACZ-BOLD). We studied CVR differences between WMH and normal-appearing white matter (NAWM) in patients with chronic SOD, hypothesizing additive influences upon CVR measured by novel, fully dynamic CVR maxima ( CVR _max ).

Methods

A cross sectional study was conducted to measure per-voxel, per-TR maximal CVR ( CVR _max ) using a custom computational pipeline in 23 subjects with angiographically-proven unilateral SOD. WMH and NAWM masks were applied to CVR _max maps. White matter was subclassified with respect to the SOD-affected hemisphere, including: i. contralateral NAWM; ii. contralateral WMH iii. ipsilateral NAWM; iv. ipsilateral WMH. CVR _max was compared between these groups with a Kruskal-Wallis test followed by a Dunn-Sidak post-hoc test for multiple comparisons.

Results

19 subjects (age 50±12 years, 53% female) undergoing 25 examinations met criteria. WMH volume was asymmetric in 16/19 subjects with 13/16 exhibiting higher volumes ipsilateral to SOD. Pairwise comparisons of CVR _max between groups was significant with ipsilateral WMH CVR _max lower than contralateral NAWM (p=0.015) and contralateral WMH (p=0.003) when comparing in-subject medians and lower than all groups when comparing pooled voxelwise values across all subjects (p<0.0001). No significant relationship between WMH lesion size and CVR _max was detected.

Conclusion

Our results suggest additive effects of microvascular and macrovascular disease upon white matter CVR, but with greater overall effects relating to macrovascular SOD than to apparent microangiopathy. Dynamic ACZ-BOLD presents a promising path towards a quantitative stroke risk imaging biomarker.

BACKGROUND

Cerebral white matter (WM) microangiopathy manifests as sporadic or sometimes confluent high intensity lesions in MR imaging with T2-weighting, and bears known associations with stroke, cognitive disability, depression and other neurological disorders ^1-5 . Deep white matter is particularly susceptible to ischemic injury owing to the deprivation of collateral flow between penetrating arterial territories, and hence deep white matter hyperintensities (WMH) may portend future infarctions ^6-8 . The pathophysiology of WMH is variable but commonly includes a cascade of microvascular lipohyalinosis and atherosclerosis together with impaired vascular endothelial and neurogliovascular integrity, leading to blood brain barrier dysfunction, interstitial fluid accumulation, and eventually tissue damage ^9-14 . Independent of the microcirculation, cervical and intracranial large vessel steno-occlusive disease (SOD) often results from atheromatous disease and is associated with increased risk of stroke owing to thromboembolic phenomena, hypoperfusion, or combinations thereof ^15-17 . White matter disease is more common in the affected hemisphere of patients with asymmetric or unilateral SOD, producing both macroscopic WMH detectable by routine structural MRI, as well as microstructural changes and altered structural connectivity detected by advanced diffusion microstructural imaging ^{18, 19} . An improved understanding of the interaction of microvascular disease (i.e., WMH) and macrovascular steno-occlusion could better inform stroke risk stratification and guide treatment strategies when coexistent. Cerebrovascular reactivity (CVR) is an autoregulatory adaptation characterized by the capacity of the cerebral circulation to respond to physiological or pharmacological vasodilatory stimuli ^20-22 . CVR may be heterogeneous and varies across tissue type and pathological states ^{1, 16} . Alterations in CVR are associated with elevated stroke risk in SOD patients, although white matter CVR, and in particular the CVR profiles of WMH, are only sparsely studied and not fully understood ^{1, 23-26} . We have previously employed blood oxygen level dependent (BOLD) imaging following a hemodynamic stimulus with acetazolamide (ACZ) in order to measure CVR (i.e. ACZ-BOLD) ^{21, 27, 28} . Despite the emergence of ACZ-BOLD as a technique for clinical and experimental use, poor signal-to-noise characteristics of the BOLD effect have generally limited its interpretation to coarse, time-averaged assessment of the terminal ACZ response at arbitrarily prescribed delays following ACZ administration (e.g. 10-20 minutes) ²⁹ . More recently, we have introduced a dedicated computational pipeline to overcome historically intractable signal-to-noise ratio (SNR) limitations of BOLD, enabling fully dynamic characterization of the cerebrovascular response, including identification of previously unreported, unsustained or transient CVR maxima ( CVR _max ) following hemodynamic provocation ^{27, 30} . In this study, we compared such dynamic interrogation of true CVR maxima between WMH and normal appearing white matter (NAWM) among patients with chronic, unilateral SOD in order to quantify their interaction and to assess the hypothesized additive effects of angiographically-evident macrovascular stenoses when intersecting microangiopathic WMH.

Acetazolamide-augmented BOLD MRI to Assess Whole-Brain Cerebrovascular Reactivity in Chronic Steno-occlusive Disease Using Principal Component Analysis

Background Exhaustion of cerebrovascular reactivity (CVR) portends increased stroke risk. Acetazolamide-augmented blood oxygenation level-dependent (BOLD) MRI has been used to estimate CVR, but low signal-to-noise conditions relegate its use to terminal CVR (CVRend) measurements that neglect dynamic features of CVR. Purpose To demonstrate comprehensive characterization of acetazolamide-augmented BOLD MRI response in chronic steno-occlusive disease using a computational framework to precondition signal time courses for dynamic whole-brain CVR analysis. Materials and Methods This study focused on retrospective analysis of consecutive patients with unilateral chronic steno-occlusive disease who underwent acetazolamide-augmented BOLD imaging for recurrent minor stroke or transient ischemic attack at an academic medical center between May 2017 and October 2020. A custom principal component analysis-based denoising pipeline was used to correct spatially varying non-signal-bearing contributions obtained by a local principal component analysis of the MRI time series. Standard voxelwise CVRend maps representing terminal responses were produced and compared with maximal CVR (CVRmax) as isolated from binned (per-repetition time) denoised BOLD time course. A linear mixed-effects model was used to compare CVRmax and CVRend in healthy and diseased hemispheres. Results A total of 23 patients (median age, 51 years; IQR, 42-61, 13 men) who underwent 32 BOLD examinations were included. Processed MRI data showed twofold improvement in signal-to-noise ratio, allowing improved isolation of dynamic characteristics in signal time course for sliding window CVRmax analysis to the level of each BOLD repetition time (approximately 2 seconds). Mean CVRmax was significantly higher than mean CVRend in diseased (5.2% vs 3.8%, P < .01) and healthy (5.5% vs 4.0%, P < .01) hemispheres. Several distinct time-signal signatures were observed, including nonresponsive; delayed/blunted; brisk; and occasionally nonmonotonic time courses with paradoxical features in normal and abnormal tissues (ie, steal and reverse-steal patterns). Conclusion A principal component analysis-based computational framework for analysis of acetazolamide-augmented BOLD imaging can be used to measure unsustained CVRmax through twofold improvements in signal-to-noise ratio. © RSNA, 2023 Supplemental material is available for this article.

Abstract 137: Diaschisis Profiles In The Hemodynamic Response To Hemodynamic Stimuli: Implications For Cerebellar Normalization In Patients With Steno-occlusive Disease

Introduction: Cerebellar hemispheres are commonly used as global references for internal normalization in hemodynamic analysis, including cerebrovascular reactivity (CVR) experiments. We have reported blood oxygen level-dependent (BOLD) MRI coupled acetazolamide for CVR; however, the influence of crossed cerebellar diaschisis (CCD) is understudied in this setting. Importantly, poor signal-to-noise traditionally limits BOLD-CVR to estimation of arbitrary exam conclusions (CVR end ). We developed a custom computational pipeline for dynamic CVR analysis, permitting unprecedented, dynamic maximal CVR (CVR max ) estimates. We describe CCD in a population of patients with chronic unilateral steno-occlusive disease (uSOD) using CVR max .

Methods: 32 acetazolamide-challenge BOLD MRI exams in 23 patients with uSOD were examined using a custom denoising and preprocessing strategy for CVR time-signal analysis.

BOLD pre and BOLD post were defined as the average of the respective first and last one-minute BOLD data. CVR end was calculated as %CVR=100*( BOLD post – BOLD pre )/ BOLD pre . CVR max was the maximal, denoised per-voxel value.

CVR end and CVR max maps were produced. Cerebellar hemispheres ipsilateral and contralateral to the diseased cerebral hemisphere were visually compared for CCD. Pearson correlations were calculated to study CVR max and CVR end in cerebral and cerebellar hemispheres.

Results: CCD could be observed in CVR end and CVR max maps (Figure 1). Significant correlations were observed between healthy cerebral and contralateral cerebellar hemispheres (r=0.5992, p=0.0011 for CVR max , r=0.5034, p=0.0054 for CVR end ). CVR max (r=0.4114, p=0.0215) but not CVR end (r=-0.085, p=0.6611) showed correlations between diseased cerebral and contralateral cerebellar hemispheres.

Conclusion: We present novel CVR max estimation from dynamic BOLD-MRI, revealing CCD otherwise unrecognized by conventional BOLD-CVR.

Predictors of Atrial Fibrillation in Patients With Stroke Attributed to Large- or Small-Vessel Disease: A Prespecified Secondary Analysis of the STROKE AF Randomized Clinical Trial

Importance

The Stroke of Known Cause and Underlying Atrial Fibrillation (STROKE AF) trial found that approximately 1 in 8 patients with recent ischemic stroke attributed to large- or small-vessel disease had poststroke atrial fibrillation (AF) detected by an insertable cardiac monitor (ICM) at 12 months. Identifying predictors of AF could be useful when considering an ICM in routine poststroke clinical care.

Objective

To determine the association between commonly assessed risk factors and poststroke detection of new AF in the STROKE AF cohort monitored by ICM.

Design, Setting, and Participants

This was a prespecified analysis of a randomized (1:1) clinical trial that enrolled patients between April 1, 2016, and July 12, 2019, with primary follow-up through 2020 and mean (SD) duration of 11.0 (3.0) months. Eligible patients were selected from 33 clinical research sites in the US. Patients had an index stroke attributed to large- or small-vessel disease and were 60 years or older or aged 50 to 59 years with at least 1 additional stroke risk factor. A total of 496 patients were enrolled, and 492 were randomly assigned to study groups (3 did not meet inclusion criteria, and 1 withdrew consent). Patients in the ICM group had the index stroke within 10 days before insertion. Data were analyzed from October 8, 2021, to January 28, 2022.

Interventions

ICM monitoring vs site-specific usual care (short-duration external cardiac monitoring).

Main Outcomes and Measures

The ICM device automatically detects AF episodes 2 or more minutes in length; episodes were adjudicated by an expert committee. Cox regression multivariable modeling included all parameters identified in the univariate analysis having P values <.10. AF detection rates were calculated using Kaplan-Meier survival estimates.

Results

The analysis included the 242 participants randomly assigned to the ICM group in the STROKE AF study. Among 242 patients monitored with ICM, 27 developed AF (mean [SD] age, 66.6 [9.3] years; 144 men [60.0%]; 96 [40.0%] women). Two patients had missing baseline data and exited the study early. Univariate predictors of AF detection included age (per 1-year increments: hazard ratio [HR], 1.05; 95% CI, 1.01-1.09; P = .02), CHA2DS2-VASc score (per point: HR, 1.54; 95% CI, 1.15-2.06; P = .004), chronic obstructive pulmonary disease (HR, 2.49; 95% CI, 0.86-7.20; P = .09), congestive heart failure (CHF; with preserved or reduced ejection fraction: HR, 6.64; 95% CI, 2.29-19.24; P < .001), left atrial enlargement (LAE; HR, 3.63; 95% CI, 1.55-8.47; P = .003), QRS duration (HR, 1.02; 95% CI, 1.00-1.04; P = .04), and kidney dysfunction (HR, 3.58; 95% CI, 1.35-9.46; P = .01). In multivariable modeling (n = 197), only CHF (HR, 5.06; 95% CI, 1.45-17.64; P = .05) and LAE (HR, 3.32; 1.34-8.19; P = .009) remained significant predictors of AF. At 12 months, patients with CHF and/or LAE (40 of 142 patients) had an AF detection rate of 23.4% vs 5.0% for patients with neither (HR, 5.1; 95% CI, 2.0-12.8; P < .001).

Conclusions and Relevance

Among patients with ischemic stroke attributed to large- or small-vessel disease, CHF and LAE were associated with a significantly increased risk of poststroke AF detection. These patients may benefit most from the use of ICMs as part of a secondary stroke prevention strategy. However, the study was not powered for clinical predictors of AF, and therefore, other clinical characteristics may not have reached statistical significance.

Trial Registration

ClinicalTrials.gov Identifier: NCT02700945.

Psychological Outcome after Hemorrhagic Stroke is Related to Functional Status

BACKGROUND

To identify opportunities to improve morbidity after hemorrhagic stroke, it is imperative to understand factors that are related to psychological outcome.

DESIGN/METHODS

We prospectively identified patients with non-traumatic hemorrhagic stroke (intracerebral or subarachnoid hemorrhage) between January 2015 and February 2021 who were alive 3-months after discharge and telephonically assessed 1) psychological outcome using the Quality of Life in Neurological Disorders anxiety, depression, emotional and behavioral dyscontrol, fatigue and sleep disturbance inventories and 2) functional outcome using the modified Rankin Scale (mRS) and Barthel Index. We also identified discharge destination for all patients. We then evaluated the relationship between abnormal psychological outcomes (T-score >50) and discharge destination other than home, poor 3-month mRS score defined as 3-5 and poor 3-month Barthel Index defined as <100.

RESULTS

73 patients were included; 41 (56%) had an abnormal psychological outcome on at least one inventory. There were 41 (56%) patients discharged to a destination other than home, 44 (63%) with poor mRS score and 28 (39%) with poor Barthel Index. Anxiety, depression, emotional and behavioral dyscontrol and sleep disturbance were all associated with a destination other than home, poor mRS score, and poor Barthel Index (all p<0.05). Fatigue was related to poor mRS score and poor Barthel Index (p=0.005 and p=0.006, respectively).

CONCLUSION

Multiple psychological outcomes 3-months after hemorrhagic stroke are related to functional status. Interventions to improve psychological outcome and reduce morbidity in patients with poor functional status should be explored by the interdisciplinary team.

Superconducting spin smecticity evidencing the Fulde-Ferrell-Larkin-Ovchinnikov state in Sr2RuO4

Translational symmetry breaking is antagonistic to static fluidity but can be realized in superconductors, which host a quantum-mechanical coherent fluid formed by electron pairs. A peculiar example of such a state is the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, induced by a time-reversal symmetry-breaking magnetic field applied to spin-singlet superconductors. This state is intrinsically accompanied by the superconducting spin smecticity, spin density-modulated fluidity with spontaneous translational-symmetry breaking. Detection of such spin smecticity provides unambiguous evidence for the FFLO state, but its observation has been challenging. Here, we report the characteristic "double-horn" nuclear magnetic resonance spectrum in the layered superconductor Sr₂RuO₄ near its upper critical field, indicating the spatial sinusoidal modulation of spin density that is consistent with superconducting spin smecticity. Our work reveals that Sr₂RuO₄ provides a versatile platform for studying FFLO physics.

Unconventional superconductivity in UTe2

The novel spin-triplet superconductor candidate UTe₂was discovered only recently at the end of 2018 and already attracted enormous attention. We review key experimental and theoretical progress which has been achieved in different laboratories. UTe₂is a heavy-fermion paramagnet, but following the discovery of superconductivity, it has been expected to be close to a ferromagnetic instability, showing many similarities to the U-based ferromagnetic superconductors, URhGe and UCoGe. This view might be too simplistic. The competition between different types of magnetic interactions and the duality between the local and itinerant character of the 5fUranium electrons, as well as the shift of the U valence appear as key parameters in the rich phase diagrams discovered recently under extreme conditions like low temperature, high magnetic field, and pressure. We discuss macroscopic and microscopic experiments at low temperature to clarify the normal phase properties at ambient pressure for field applied along the three axis of this orthorhombic structure. Special attention will be given to the occurrence of a metamagnetic transition atH_m= 35 T for a magnetic field applied along the hard magnetic axisb. Adding external pressure leads to strong changes in the magnetic and electronic properties with a direct feedback on superconductivity. Attention is paid on the possible evolution of the Fermi surface as a function of magnetic field and pressure. Superconductivity in UTe₂is extremely rich, exhibiting various unconventional behaviors which will be highlighted. It shows an exceptionally huge superconducting upper critical field with a re-entrant behavior under magnetic field and the occurrence of multiple superconducting phases in the temperature-field-pressure phase diagrams. There is evidence for spin-triplet pairing. Experimental indications exist for chiral superconductivity and spontaneous time reversal symmetry breaking in the superconducting state. Different theoretical approaches will be described. Notably we discuss that UTe₂is a possible example for the realization of a fascinating topological superconductor. Exploring superconductivity in UTe₂reemphasizes that U-based heavy fermion compounds give unique examples to study and understand the strong interplay between the normal and superconducting properties in strongly correlated electron systems.

Abstract TP96: Mild Luminal Stenosis Of Parent Artery And Neurologic Deterioration After Acute Lacunar Stroke

Introduction: Neurologic deterioration (ND) occurs in a quarter of acute lacunar infarcts and may lead to severe disability, but underlying pathophysiology of ND remains poorly understood. We sought to identify risk factors and clinical characteristics associated with ND.

Methods: This retrospective observational study included consecutive patients with acute lacunar stroke admitted to New York University Langone Health and Brown University (NYU/Brown). Lacunar stroke was defined as a subcortical infarct <1.5 cm on CT or <2 cm on diffusion-weighted imaging without significant stenosis (>50%) in the parent vessel and no cardioembolic source. We defined ND as any neurologic deterioration referable to the lacunar stroke and not related to a medical or non-cerebrovascular neurological complication. We used logistic regression analyses to determine associations between ND and luminal stenosis (<50%) vs no luminal stenosis, after adjustment for key confounders. Furthermore, we attempted to validate findings using the Columbia University (CU) stroke registry and perform a meta-analysis combining the derivation and validation groups due to expected small samples and event rates.

Results: The NYU/Brown sample included 205 patients, of whom 41 (20%) had ND. In adjusted models, we found no definite association between luminal stenosis and ND (aOR 1.74, 95% CI 0.73-4.14). From CU, 361 total patients were included, of whom 59 (16%) had ND. In adjusted models, we found an association between luminal stenosis and ND (aOR 2.28 95% CI 1.15-4.50). Meta-analysis of both cohorts found luminal stenosis associated with ND (RR [95% CI]: 1.75 [1.23-2.49]).

Conclusions: In this multi-center study, luminal stenosis (<50%) may be associated with ND following an acute lacunar infarct. Larger studies using high-resolution vascular imaging modalities such as vessel wall imaging are needed to validate our findings.

Abstract WMP56: Delay To Stroke Diagnosis In Patients That Require The Use Of An Interpreter

Introduction: Delay to stroke diagnosis can postpone appropriate treatment leading to worse outcomes. We hypothesize that interpreter use can contribute to a delay to treatment.

Methods: We identified consecutive patients between January 2019 and June 2021 with acute stroke (hemorrhagic or ischemic) using the Get with the Guidelines Database (GWTG). We determined the requirement for interpreter via chart review. We assessed time from last known well (LKW) to CT. We also looked at time to treatment, defined as the time from LKW to tPA administration or groin puncture. Finally, we assessed the difference in outcomes in patients using discharge modified Rankin Score (mRS). We compared these values for patients that did and did not require the use of an interpreter.

Results: We identified 2,576 patients from GWTG and found 1,306 patients (mean age 69±16, 48% female) with acute stroke notifications. The majority (78%) of these patients were diagnosed with ischemic stroke. For patients presenting with an acute stroke, 27% required interpreter use. For patients who required an interpreter, Spanish (28%), Russian (21%) and Cantonese (18%) were the most common primary language. Compared to patients who spoke English, patients with interpreter requirements were older (73±13 years vs 68±16 years) and had a higher median NIHSS admission score (8[3-18] vs 4[2-13]), p<.05 for both. There was no difference in arrival time to stroke code activation. However median time to CT [IQR] from LKW was longer for patients who required an interpreter (334 minutes [121-955] vs. 274 minutes [106-765], p=.03). Patients who required an interpreter were less likely to get tPA (15% vs 24%, p=.05), and had a longer time between LKW and treatment (60 minutes [36-85] vs 48 [31-75], p=.02). Patients who required an interpreter had a higher discharge mRS (3 [1-4] vs 2 [1-4], p=.02).

Discussion: Interpreter requirement was associated with longer time to stroke diagnosis, reflecting a pre-hospital delay in the identification of stroke symptoms, despite the higher NIHSS. These patients were less likely to receive tPA and had a higher discharge mRS. Interpreter requirement merits consideration for systemic changes that might prevent this health care administration disparity.

Abstract TP99: Hemorrhagic Conversion Of Ischemic Stroke Is Associated With Hematoma Expansion

Objectives: Hemorrhagic conversion of ischemic stroke (HCIS) is a common complication of cerebral ischemia and is associated with worse stroke outcomes. Differentiation between HCIS and other causes of intracerebral hemorrhage (ICH) can be challenging in practice. We sought to determine whether imaging features of hematoma expansion (HE) can be used to discriminate HCIS from other etiologies of ICH.

Materials and Methods: We performed a retrospective review of patients admitted to two large urban hospitals between 2015-2020 with non-traumatic ICH and at least two head CTs within the initial 24 hours and brain MRI prior to discharge to assist with etiology identification. ICH etiology was determined by expert consensus. HE was defined as ≥6 mL and/or ≥33% growth between the first and second scan. Clinical and imaging covariates were studied using univariable and multivariable regression to assess the relationship between cause of intracerebral hemorrhage and HE. We evaluated whether HE was associated with functional status on discharge.

Results: 258 patients (median age 66 [51-76], 43% female) met our inclusion criteria including 37 (14%) with HCIS as the presumed cause of hemorrhage. Etiology for ICH was hypertensive in 29%, vascular in 27%, and cerebral amyloid angiopathy in 13%. HE occurred in 11/37 (30%) patients with HCIS, and in 33/221(15%) patients with other causes (p= 0.04). History of anticoagulation use was more frequent in patients with HCIS (24% vs 11%, p= 0.04), although there was no significant difference in admission INR or platelet count. There was no difference in age, admission systolic blood pressure, admission hematoma size or ICH score between groups. HCIS was significantly associated with HE (OR 2.4, CI 1.08-5.34, p=0.03) on univariable analysis. When controlling for hematoma size and anticoagulant use, the relationship between HCIS and HE remained significant (aOR 2.68, CI 1.17-6.13, p=0.02). Patients with HCIS had a higher modified Rankin scale on discharge when compared to those with ICH due to other causes ((mRS 5 [4-5.5] vs. mRS 4 [2-4], p<0.001).

Conclusion: HE within the first 24 hours is more common in HCIS than in other etiologies of ICH. Imaging signatures of HE may be contributory towards determining ICH etiology.

Central Retinal Artery Visualization with Cone-Beam CT Angiography

Background There are multiple tools available to visualize the retinal and choroidal vasculature of the posterior globe. However, there are currently no reliable in vivo imaging techniques that can visualize the entire retrobulbar course of the retinal and ciliary vessels. Purpose To identify and characterize the central retinal artery (CRA) using cone-beam CT (CBCT) images obtained as part of diagnostic cerebral angiography. Materials and Methods In this retrospective study, patients with catheter DSA performed between October 2019 and October 2020 were included if CBCT angiography included the orbit in the field of view. The CBCT angiography data sets were postprocessed with a small field-of-view volume centered in the posterior globe to a maximum resolution of 0.2 mm. The following were evaluated: CRA origin, CRA course, CRA point of penetration into the optic nerve sheath, bifurcation of the CRA at the papilla, visualization of anatomic variants, and visualization of the central retinal vein. Descriptive statistical analysis was performed. Results Twenty-one patients with 24 visualized orbits were included in the analysis (mean age, 55 years ± 15; 14 women). Indications for angiography were as follows: diagnostic angiography (n = 8), aneurysm treatment (n = 6), or other (n = 7). The CRA was identified in all orbits; the origin, course, point of penetration of the CRA into the optic nerve sheath, and termination in the papilla were visualized in all orbits. The average length of the intraneural segment was 10.6 mm (range, 7-18 mm). The central retinal vein was identified in six of 24 orbits. Conclusion Cone-beam CT, performed during diagnostic angiography, consistently demonstrated the in vivo central retinal artery, demonstrating excellent potential for multiple diagnostic and therapeutic applications. © RSNA, 2021 Online supplemental material is available for this article.