bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WMP26: Clinical Characteristic-Driven Machine Learning Models for the Prediction of Stroke Subtypes and Eligibility of Endovascular Thrombectomy
Authors: Yoshie Tomohide , Yoshimura Sohei , Sakuraba Makino , Wada Shinichi , Miwa Kaori , Miyamoto Yoshihiro , Miyazaki Junji , Yazawa Yukako , Kamiyama Kenji , Minematsu Kazuo , Iihara Koji , Toyoda Kazunori , Koga Masatoshi
Published: January 2025

Introduction:
Several pre-hospital scales predict ischemic stroke due to large vessel occlusion; however, these scales often fail to detect atypical endovascular thrombectomy (EVT) cases, including posterior circulation and distal vessel occlusion. Additionally, these pre-hospital scales cannot differentiate between stroke subtypes, such as ischemic stroke and intracerebral hemorrhage. We aimed to develop machine learning (ML) models to predict stroke subtypes and EVT eligibility.

Methods:
We conducted an analysis using data from the Japan Stroke Data Bank, a nationwide acute stroke registry. Patients with ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage who were hospitalized between 2016 and 2020 were included in this study. We developed two ML models: (1) a model to predict patients who received EVT, and (2) to predict stroke categories (ischemic stroke treated with EVT, ischemic stroke treated with tPA, ischemic stroke without EVT or tPA, intracerebral hemorrhage, and subarachnoid hemorrhage). Patient data were divided into the derivation cohort (data from 2016 to 2019) and the validation cohort (data in 2020). The input variables for the ML models consisted of 129 clinical characteristics, including past medical history and neurological examination findings. Imaging and laboratory data were not utilized in the ML process. We initially developed the ML models using LightGBM algorithm with all 129 variables. Subsequently, we selected the top 10 variables for model development by the feature importance and Brute-force method, comparing commonly used pre-hospital scales to predict patients with EVT.

Results:
Of the 62,588 patients included in the study, 4,353 were treated with EVT, 3,001 with tPA, 39,710 had ischemic stroke treated without EVT or tPA, 12,498 had intracerebral hemorrhage, and 3,028 had subarachnoid hemorrhage. The area under the curve (AUC) for predicting patients treated with EVT was 0.828 (95% CI 0.817-0.839). For predicting the five stroke categories, the multiclass AUC was 0.848, and the micro-average F1 score was 0.705. Using the brute-force algorithm to select 10 variables, the ML model for predicting EVT treatment achieved an AUC of 0.794 (95% CI 0.784-0.805), outperforming commonly used pre-hospital scales (AUC 0.584-0.690).

Conclusions:
The ML models utilizing only clinical characteristics can accurately predict stroke subtypes and EVT eligibility, offering a potential improvement over current pre-hospital scales.
Abstract WMP28: High Mechanical Thrombectomy Procedural Volume is Not a Reliable Predictor of Improved Thrombectomy Outcomes in Patients with Acute Ischemic Stroke in the United States
Authors: Qureshi Adnan , Maqsood Hamza , Bhatti Ibrahim , Ford Daniel , Gomez Camilo , Hanley Daniel , Hassan Ameer , Nguyen Thanh , Siddiq Farhan , Spiotta Alejandro , Zaidi Syed , Kwok Chun Shing
Published: January 2025

Background:
The volume of mechanical thrombectomy (MT) performed at hospitals is used as one of the criteria for advanced level designation for stroke care.

Objective:
Our study sought to determine the relationship between annual MT procedural volume and in-hospital outcomes in acute ischemic stroke patients undergoing MT in the United States.

Methods:
We analysed from the National Inpatient Sample from 2016 to 2020. The hospitals were groups into quartiles based on the volume of MT procedures performed within the calendar year. We compared the rates of routine discharge/home health care; in-hospital mortality, and post-treatment intracranial haemorrhage (ICH) between the quartiles after adjusting for potential confounders.

Results:
Patients undergoing MT ranged from 15,395 in quartile 1 to 78,510 MT in quartile 4. There were lower rates of discharge home/self-care of 22.5%, 20.8% and 20.8% for quartiles 2, 3 and 4, respectively compared with 34.9% in the quartile 1. The odds of ICH increased to 1.81 (p<0.001), 1.84 (p<0.001), and 1.98 (p<0.001) among the quartiles from lowest to highest procedural volumes. The odds of home discharge/self-care decreased to 0.66 (p<0.001), 0.60 (p<0.001), and 0.63 (p<0.001) among the quartiles from lowest to highest procedural volumes. The odds of in-hospital mortality increased to 1.92 (p<0.001), 1.99 (p<0.001), and 1.84 (p<0.001) among the quartiles from lowest to highest procedural volumes.

Conclusions:
We observed a paradoxical relationship between adverse outcomes and annual procedural volume of MT at the hospital presumably due to higher severity of acute ischemic stroke treated at high volume hospitals.
Abstract WMP29: Evaluating Exemption from Informed Consent and Deferred Consent Practices in Acute Stroke Trials: A Scoping Review of Recent Trends and Recruitment Efficiency．
Authors: Fukuda-Doi Mayumi , Koga Masatoshi , Inoue Manabu , Yoshimura Sohei , Ishigami Akiko , Yamaguchi Eriko , Yamamoto Haruko , Toyoda Kazunori
Published: January 2025

Purpose:
Recruiting participants for acute ischemic stroke trials is challenging due to difficulties in obtaining written informed consent in urgent settings. Alternative consent methods, like deferred consent and Exemption from Informed Consent (EFIC), have been proposed to facilitate timely intervention and improve trial feasibility. This review examines the impact of these methods on recruitment efficiency in both ischemic stroke and ICH trials.

Methods:
A scoping review of trials on acute ischemic stroke and ICH interventions (enrollment ≤24 hours from onset) published between January 2013 and March 2023 was conducted. Studies were categorized by consent methods, and trial characteristics were analyzed to compare recruitment efficiency. The review protocol was pre-registered on the Open Science Framework (https://osf.io/5rkc2).

Results:
A total of 170 trials met our inclusion criteria. Of these, 118 trials used conventional written informed consent (Conventional group), while 52 trials (30.6%) adopted alternative consent methods including deferred consent and EFIC (Alternative group). In univariable analysis, the Alternative group had a significantly shorter maximum allowable time from onset/LKW to randomization/enrollment compared to the Conventional group (6 hours [IQR 4-12] vs. 9 hours [IQR 5-24], p=0.03). There were no significant differences between the groups in terms of the number of participating countries, sites, or overall enrollment duration. However, the number of withdrawals (in counts) was significantly higher in the Alternative group (2.8 ± 5.8 vs. 9.3 ± 13, p<0.001). Additionally, alternative consent strategies were more frequently used in pre-hospital settings, where patients were often enrolled before a clinical diagnosis was confirmed. In the multivariable regression analysis, adjusting for operational factors (number of participating countries, sites, patients) and trial design elements (blinding, randomization, intervention), the Alternative group showed no significant difference in enrollment duration compared to the Conventional group (β = -0.32 weeks, 95% CI: -8.1 to 7.4, p = 0.93).

Conclusions:
Alternative consent methods, used in approximately 30% of acute stroke trials, allow quicker enrollment without significantly impacting overall enrollment duration. However, these methods are linked to higher dropout rates. These strategies require careful implementation to balance speed and trial feasibility.
Abstract WMP30: Partnering with an Urban Safety Net Hospital to Deliver Stroke Preparedness in the Emergency Department
Authors: Springer Mellanie , Hodges Tiffany , Brown Devin , Miller Robert , Morgenstern Lewis , Sales Anne , Zimmerman Marc , Skolarus Lesli
Published: January 2025

Introduction:
Among Black Americans, the time between stroke symptom onset and hospital arrival is longer than among White Americans. We aimed to adapt and test a stroke preparedness intervention for emergency department patients in Flint Michigan, a majority Black American community.

Methods:
In this randomized controlled trial (2/2022–8/2023), eligible participants were ≥18 years old, English-speaking, and lacked severe pain or any other medical condition that might distract from participation. Participants were administered the video-STAT, which queries response to 4 stroke and 4 non-stroke video vignettes (scored 0-8 for correctly designating intent to call 911 for stroke) and tests recognition of stroke vignettes (scored 0-4). Only responses to stroke video vignettes are scored. Participants were randomized to the intervention condition (a pamphlet and video teaching stroke symptoms and the importance of calling 911) or the control condition (a pamphlet about the American Heart Association’s Life’s Simple 7). The primary outcome was the intent to call 911 score immediately post-exposure (secondary endpoint) and at 1 month (primary endpoint). The secondary outcome was the stroke recognition score. Linear mixed models adjusting for pre-exposure intent to call 911 or stroke recognition score, and demographic and clinical covariates evaluated the association between treatment group and the outcomes.

Results:
A total of 330 people participated (n=171 control group; n=159 intervention group; mean age= 45, 61% female, 49% Black participants). Pre-exposure, the control and intervention groups did not differ in intent to call 911 (mean ± standard deviation (SD) score of 5.3 ± 2.2 and 5.4 ± 2.1 in the control and intervention groups) or recognition of stroke vignette scores (mean ± SD score of 2.9 ± 1.0 and 2.8 ± 1.1 in the control and intervention groups). Post-exposure, the intervention group had a higher intent to call 911 score than the control group (adjusted mean between-group difference, 1.14 [95% CI, 0.78 – 1.50] immediately post-exposure; 1.12 [95% CI, 0.64 -1.59] at 1-month post-exposure). The intervention group also correctly recognized more stroke vignettes than the control group (adjusted mean difference, 0.40 [95% CI, 0.23-0.56] immediately post-exposure; 0.51 [95% CI, 0.30-0.72] at 1-month post-exposure).

Conclusions:
The ED-based educational intervention resulted in greater intent to call 911 for stroke and greater stroke symptom recognition.
Abstract WMP35: Diagnostic and Therapeutic Challenges with Spinal Cord Infarction: A Real-World Experience from a Comprehensive Stroke Center
Authors: Shakeel Hassan Abdullah , Saim Muhammad , SINGH ROMIL , Cerejo Russell
Published: January 2025

Introduction:
Spinal cord infarction (SCI) is a rare condition that accounts for only 1% to 2% of all ischemic strokes and 5% to 8% of acute myelopathies [1]. We aim to figure out the diagnostic and therapeutic challenges clinicians face with spinal cord infarction given scarcity of published data, overlapping clinical and neuroimaging findings with alternate etiologies for acute myelopathy, and utility of spinal diffusion weighted imaging (DWI) sequences in differentiating between different causes of acute myelopathy.

Methods and Material:
Retrospective review of electronic medical records was done. Patients with discharge diagnosis of spinal stroke with DWI imaging evidence of infarction, challenging cases with positive DWI imaging but different pattern of clinical presentation and exam findings were included in the study. Cases without spinal DWI imaging were excluded.

Results:
Among the 34 DWI-positive patients included in the study with suspected SCI, the average age at presentation was 60 years, and 22 patients (64.7%) had vascular risk factors. A rapid onset of severe deficits, reaching their peak within 12 hours, was observed in 14 patients (41.1%), while 20 patients (58.8%) experienced a gradual decline. Sensory involvement was noted in 26 patients (76.4%), with 13 of these patients (50%) selectively retaining vibration and proprioception. Out of the 34 suspected SCI cases, 15 patients (44.1%) initially received alternative diagnoses, such as TM, NMOSD, Metastatic disease, Post-traumatic cord injury, or Post-laminectomy syndrome. However, after repeated imaging and continuous outpatient follow-up, 7 patients (46.6%) were eventually diagnosed with SCI. The mean MRS score at presentation was 1, at 3 months it was 4, and at 1 year it was 4.

Conclusion:
Although the overall incidence of SCI is low, it should be considered in patients presenting with acute progressive myelopathic symptoms, even in the absence of vascular risk factors. Factors such as patient demographics and MRI lesion characteristics—including lesion location and ADC correlation—can help differentiate acute demyelinating conditions from SCI. Additionally, a third diagnosis should be considered, beyond just TM and SCI, as not all strokes follow typical patterns, and clinical presentation can vary significantly among patients. Furthermore, recovery outcomes can differ widely, emphasizing the need for individualized patient management.
Abstract WMP38: Racial disparities in functional outcome after ischemic stroke
Authors: Robinson David , Sucharew Heidi , Ding Lili , Haverbusch Mary , Stanton Robert , Madsen Tracy , Menzies Lauren , LaPorta Joseph , Wechsler Paul , Wright Shea , Stamm Brian , Nobel Lisa , Aziz Yasmin , Slavin Sabreena , Walsh Kyle , DeLosRiosLaRosa Felipe , Woo Daniel , Ferioli Simona , Kleindorfer Dawn , Kissela Brett
Published: January 2025

Background:
Black individuals are at a higher risk of stroke, but little is known about racial disparities in functional outcome. Using a representative population-based study, we examined disparities in outcome over multiple timepoints in the first year after acute ischemic stroke (AIS).

Methods:
We ascertained all hospitalized AIS events in the Greater Cincinnati Northern Kentucky region from July 2019-December 2020 (Black individuals) and January 2020-December 2020 (White individuals). Potential cases were identified by ICD codes, abstracted, and physician adjudicated. Only patients who survived their initial hospitalization were included. Using a validated approach, modified Rankin Scale (mRS) was determined retrospectively at discharge, 3 months, 6 months, and 1-year post-stroke. Mixed effect ordinal regression was used to investigate the effect of Black race on functional outcome, after adjustment for relevant factors. We collapsed mRS scores of 5 and 6 into one category for the ordinal shift analyses due to the small number of patients with an mRS of 5. A race:time interaction term was considered to assess whether the race-based differences in functional outcome varied by timepoint. Missing data was handled via full information maximum likelihood.

Results:
Over the study period, we identified 2541 AIS survivors, of whom 816 (32%) were Black and 1306 (51%) were women (Graphic 1). Unadjusted distributions of mRS scores over 1 year of follow-up are shown in Graphic 2. At 12 months, 25.4% of White individuals (434/1707) and 21.2% of Black individuals (169/799) had an mRS of 0 or 1. When adjusted for age and sex, Black race was associated with a shift towards worse ordinal mRS (Graphic 3, cOR 1.48, 95% CI 1.30-1.68). When other potential confounders were added to the model, the effect of Black race was attenuated but remained significant (cOR 1.16, 95% CI 1.02-1.31). There was no significant interaction between Black race and time after stroke in either model (0.10 and 0.09, respectively).

Conclusions:
Using one of the first population-based studies of long-term post-stroke functional outcomes in the U.S., we found that Black individuals experience worse functional outcomes, and this effect was incompletely attenuated when adjusted for comorbidities and initial management. Further research is needed to understand whether these disparities are driven by modifiable social determinants that impact stroke rehabilitation.
Abstract WMP40: Rehabilitation Therapy Utilization by Stroke Survivors Across US Insurance Payors
Authors: Dishman Deniz , Ukhanova Maria , Indupuru Hari Kishan R , Stevens Emily , Savitz Sean
Published: January 2025

Introduction:
Rehabilitation is essential to stroke recovery; however, access to rehabilitation varies in the US. We report recent national utilization rates of different rehabilitation disciplines in stroke survivors covered by different payors in the US. There is uncertainty how utilization equates to actual number of therapy sessions.

Methods:
This is a retrospective, population-based, observational study using claims data of the Merative™ MarketScan® commercial database and the 5% national sample of Medicare Fee-For-Service (FFS) claims for ischemic and intracerebral hemorrhage (ICH) stroke hospitalizations among US adults aged 18 years and older during the period from 2016 to 2020. The study outcome was a new speech pathology (SLT), occupational therapy (OT), or physical therapy (PT) encounter during the first year after discharge.

Results:
57,647 total cases were identified with 30% Medicare FFS, 33% Truven (Commercial) Medicare Advantage plan (65 years and older), and 37% Truven commercial (less than 65 years old). Stroke sequela included hemiplegia 52%, aphasia 23%, dysphagia 17%, and cognitive impairment 14%. Figure 1 shows the visits (mean) per discipline over time. The highest visits among all disciplines were for PT and the payor covering the highest number of services was Medicare FFS at all time points: 30 days (mean 2.02, SD 3.04), 90 days (mean 4, SD 6.01), and at 1 year (mean 8.25, SD 12.8). For all services covered by payors, PT had the most visits (39%) followed by OT (30%), and SLT (22%) and 9% of cases could not be differentiated as either PT or OT.

Conclusions:
Utilization based on the number of outpatient visits is abysmally low in all rehabilitation disciplines in the time frame when the brain is maximally responsive to rehabilitation therapy despite documented impairments. Our results are consistent across 3 different payors demonstrating that rehabilitation therapy is grossly underutilized over the first year after stroke in all payor groups in the US.
Abstract WMP42: Exploring The Neural Basis Of Prognostic Tools For Upper Limb Recovery After Stroke:
Lesion Topography Of SAFE And Other Medical Research Council Scale Scores
Authors: Chilvers Matthew , Hayward Kate , Hill Michael , Dukelow Sean
Published: January 2025

Background:
The Medical Research Council (MRC) scale is used to assess the impact of stroke on muscle strength. Shoulder abduction and finger extension, collectively (SAFE), have been suggested to have prognostic value for stroke outcomes (e.g. PREP-2), and been recommended for use in screening for clinical trials. Few studies have assessed the neuroanatomy associated with SAFE, and other upper extremity MRC scores after stroke. In this study, we used voxel-based lesion symptom mapping (VLSM) to assess lesion locations associated with worse SAFE scores, as well as other movements assessed by the MRC scale.

Methods:
A trained therapist assessed 12 individual MRC scores at the: shoulder (flexion, extension, abduction, internal and external rotation), elbow (flexion and extension), wrist (flexion and extension) and fingers (flexion, extension and abduction). Clinical neuroimaging (MRI and/or CT) was collected for all participants, and lesioned voxels traced by trained assessors and normalized to a standard template space. VLSM analysis was conducted for all 12 MRC scale scores, and SAFE score, using NiiStat. Only voxels lesioned in >10% of participants were tested.

Results:
We recruited 226 stroke participants at 2 weeks post-stroke (mean age=62.6; Males=147; Right Hemisphere=131; Ischemic=199, Hemorrhagic=27). VLSM analysis showed that worse SAFE scores were significantly associated with lesions in voxels in the left and right corona radiata, adjacent and dorsal to the lateral ventricles, and consistent with the upper portions of the corticospinal tract in each hemisphere. Additionally, voxels in the putamen were also significantly associated with worse SAFE scores. Interestingly, all other MRC scores were also associated with similar lesion topography to SAFE.

Conclusion:
This work demonstrates a consistent association between SAFE scores and corticospinal tract damage. The integrity of the corticospinal tract has frequently been suggested as a biomarker of stroke recovery. These findings shed light on why SAFE might be a valuable prognostic tool for stroke recovery, and a quick and efficient screening tool for clinical trials. Despite increasing use of SAFE, other muscle weakness, assessed by the MRC scale, is also represented by the same neuroanatomic regions and may share similar prognostic abilities. Continued investigation into effective prognostic tools for upper-limb recovery is warranted.
Abstract WMP45: Home Time May Not be a Suitable Measure of Functional Recovery to Compare Rehabilitation Outcomes in Stroke Patients
Authors: Hailat Raed , Thompson Mike , Nickles Adrienne , Oostema John , Luo Zhehui , de los Campos Gustavo , Reeves Mathew
Published: January 2025

Introduction:
There has been an ongoing debate regarding the effectiveness of inpatient rehabilitation facility (IRF) and skilled nursing facility (SNF) in promoting functional recovery. Home time is a valid measure of functional recovery in stroke patients that is often used in outcome studies. Considering that SNF patients have twice the length of stay compared to IRF patients, our objective was to explore whether home time is a suitable measure to compare the effectiveness between IRF and SNF in achieving functional recovery.

Methods:
We probabilistically linked data from Michigan’s Coverdell Stroke Program and Michigan Value Collaborative multipayer claims database for Medicare FFS beneficiaries hospitalized with acute stroke (ICD-10 I61-I63) between 2016-2020. Patients admitted to IRF or SNF after hospital discharge were confirmed using claims data. Home time was calculated over 90-days and 1-year following hospital discharge by subtracting the number of days spent in inpatient setting (i.e., IRF, SNF, and long-term care) from the number of days alive. We calculated the crude and inverse probability of treatment weighted (IPTW) mean difference of home time between IRF and SNF groups. We conducted a sensitivity analysis to examine the effect of time spent in the same rehabilitation setting over 30-days post discharge on home time.

Results:
From a cohort of 14,316 linked patients, we identified 2,995 (20.9%) and 2,948 (20.6%) patients directly admitted to IRF or SNF following stroke hospitalization, respectively. Compared to SNF patients, IRF patients were younger, more likely to be male, had minor strokes (NIHSS 1-4), and were able to ambulate at discharge. The unadjusted 90-day and 1-year mean home time were 15.6 and 67.6 days higher among IRF patients compared to SNF patients, respectively (Table). After accounting for rehabilitation time during 30-days post discharge, 90-day and 1-year unadjusted mean difference in home time remained higher among IRF patients compared to SNF patients but was reduced to 4.6 and 56.5 days, respectively. Using the amended home time, the adjusted 90-days mean difference was almost zero and not significantly different (0.5 days) but remained significantly different over 1-year (35.7 days).

Conclusions:
Home time is heavily impacted by rehabilitation length of stay. Future rehabilitation related studies should be cautious when using home time as a measure of functional recovery, especially over short duration of follow-up.
Abstract WMP46: FLAIR Hyperintense Vessels in the Right MCA Parietal Region Predict Left Viewer-Centered Neglect in Acute Right Hemisphere Stroke Patients
Authors: Raman Ashley , Hillis Argye
Published: January 2025

Both left hemisphere (LH) and right hemisphere (RH) stroke can cause contralesional viewer-centered neglect (VCN) or stimulus-centered neglect (SCN). Studies using perfusion imaging have shown that in acute stroke, hypoperfusion beyond the infarct contributes to deficits, including neglect. However, perfusion imaging is not always available. FLAIR hyperintense vessel (FHV; Fig. 1) number and site estimate the volume and site of hypoperfusion. We hypothesized that FHV rating in the right parietal cortex would contribute to VCN.

A series of 256 consenting acute stroke patients (82 LH and 174 RH) completed a neglect task with 30 ovals – 10 full, 10 with a gap on the left, and 10 with a gap on the right. Patients were asked to circle full ovals and cross out ovals with a gap on either side. We defined VCN as >10% of ovals unmarked after the most extreme mark (Fig. 2), and SCN as neglecting or incorrectly marking >10% of contralesional gaps (Fig. 3). On FLAIR sequences, we identified FHVs in 4 MCA regions: frontal, temporal, parietal, and insular, as well as ACA and PCA territories. Each region was scored from 0 to 2: 0 = no FHVs; 1 = 1-2 FHVs on 1-2 slices; 2 = 3 or more vessels on 1 slice or 3 or more slices with at least 1 FHV (total=0-12). Infarct volume was calculated after manual tracing of lesions on DWI. We used multivariable logistic regression, with the presence of VCN or SCN as the dependent variable, and FHV ratings in each territory, infarct volume, and age as independent variables. We used chi squared tests to test associations between dichotomous variables.

In LH stroke, SCN was more common than VCN (21% vs. 5%; X
2
= 9.3; p=0.002). VCN was more common in RH than LH stroke (13% vs 5%; X
2
= 4.1; p=0.04). In RH stroke, left VCN was independently predicted by age (p=0.005), volume of infarct (p<0.0001), and FHV score in the right parietal cortex (p=0.03). Together, these accounted for 40% of the variance in left VCN (pseudo r
2
= 40.2; p<0.00001). In LH stroke, right VCN was not
independently
predicted by any variable. However, together, age, infarct volume, and FHV in each region accounted for 52% of the variance in right VCN (pseudo r
2
= 51.8; p=0.008). SCN was not predicted by these variables.

In conclusion, we showed that left VCN in acute RH stroke can be predicted by age, infarct volume, and FHV score in the right parietal cortex. These results illustrate the usefulness of FHV in specific locations for estimating clinically significant hypoperfusion.
Abstract WMP47: Exploring the Neural Mechanism of Post-Thalamic Stroke Apathy Based on Disconnection-Symptom Mapping Analysis
Authors: Ruosu Pan , Ye Chen , Tang Biqiu , Lui Su , Wu Bo
Published: January 2025

Background:
Occurrence of post-stroke apathy (PSA) is associated with worse outcomes and poorer quality of life. Particularly, post-thalamic stroke apathy was repeatedly reported. In this study, we performed disconnection-based analyses to reveal the neural basis of post-thalamic stroke apathy from both focal and network perspectives.

Method:
This study recruited first-ever unilateral thalamic ischemic stroke patients. The Lille Apathy Rating Scale was used to characterize the appearance and severity of apathy. Patient’s lesion masks were embedded into normative connectome to generate functional or structural disconnection maps. Support Vector Regression-based Multivariate Lesion-Symptom Mapping and Disconnection-Symptom Mapping were employed to explore associations between lesion locations, structural and functional disconnections, and PSA.

Results:
A total of 92 patients with thalamic infarction were included. No significant associations were found between thalamic lesion locations and PSA. However, structural disconnection in the anterior thalamic radiation and functional disconnection in the bilateral medial prefrontal cortex, bilateral inferior frontal gyrus, bilateral anterior insular cortex, right inferior parietal lobule, and right superior temporal gyrus were significantly associated with PSA.

Conclusion:
The study revealed that apathy following thalamic ischemic stroke is associated with disruptions in thalamocortical networks rather than specific lesion locations. These findings suggest that post-thalamic stroke apathy is a network disorder, driven by functional diaschisis and secondary neurodegeneration. Understanding these mechanisms may inform treatment targets and improve post-stroke rehabilitation strategies.
Abstract WMP48: Estimated Electrical Field With Transcranial Direct Current Stimulation (tDCS) and Response to Gait Therapy Combined With tDCS in Chronic Stroke Patients
Authors: Yaghmoor Bassam , Skelly Margaret , McCabe Jessica , Salameh Ahlam , Bikson Marom , Duncan Kelsey , Mosca Luke , Leonhardt Lisa , Hisel Terri , Hardin Elizabeth , Zink Elizabeth , Pundik Svetlana
Published: January 2025

Introduction:
Transcranial Direct Current Stimulation (tDCS), a form of non-invasive brain stimulation, is a promising adjunct intervention that may enhance motor-learning induced neuroplasticity. It is safe and easy to administer, but current distribution can vary due to anatomy. Furthermore, it is not clear how strong the stimulation can and should be to achieve the best outcomes. In this analysis, we evaluated whether higher estimated electric field (e-field) is related to better response to gait training that is combined with tDCS.

Methods:
We used data of the active group from a randomized control trial testing response to 10-session gait therapy with or without tDCS. Therapy consisted of 30 min of virtual-reality obstacle clearance training on a treadmill followed by 30 min of overground stance phase training. Bihemispheric 2mA tDCS was delivered using 5x5 cm pads targeting primary motor areas during the first 15 min of training. Outcomes for this analysis included lower extremity Fugl-Meyer (FM) and Timed Up and Go (TUG). E-field was computed from a volume conduction model based on each individual’s structural MRI. The maximum electric field in sensorimotor cortical regions were extracted and correlated with post minus pre changes in outcome measures.

Results:
Active tDCS group’s (n=21) characteristics were 61.6±11.1 y/o; 28.6% female; 4.3±3.4 years post-stroke; 47.6% left affected hemisphere. Group improvements were: FM, 3 points (p= 0.0002); TUG, 2.74 s (p=0.0005). Correlation between the changes in FM and TUG was low (r=0.13). The highest e-field was 0.41±0.11 V/m, contralesionally and 0.39±0.11 V/m, ipsilesionally. The highest e-field occurred most commonly (in 13 out of 21 subjects) in the medial postcentral gyrus, both ipsi- and contralesionally. In the exploratory analysis of subjects who improved on both outcome measures (n=16), greater improvement on FM and TUG correlated with higher e-field strength for several regions (Table 1).

Conclusion:
Higher e-field produced by tDCS might influence response to rehabilitation. E-field that is achieved with tDCS is likely different in the ipsi- and contra-lesional hemispheres. These findings may need to be considered while designing tDCS intervention for post-stroke rehabilitation.
Abstract WMP5: Comparative analysis of methods to derive number needed to treat over the entire range of global disability on the modified Rankin Scale
Authors: Mistry Eva , Gornbein Jeffrey , Saver Jeffrey
Published: January 2025

Background:
Number needed to treat (NNT) is an intuitive measure of treatment benefit/harm to both clinicians and patients. For ordinal endpoints, NNTs derived by dichotomously collapsing scales are easily calculated but almost always underestimate the amount of benefit a treatment confers. Several methods have been described to derive NNT for ordinal outcomes. We aimed to directly compare the performance of each of the most widely described methods of ordinal NNT derivation.

Methods:
NNT was calculated for eight stroke clinical rials/meta-analyses purposively selected to include small, moderate and large treatment effects and diverse treatment types, including thrombolysis (NINDS tPA, IST3), thrombectomy (HERMES, AURORA, Large Core EVT), surgery for AIS (Hemicraniectomy), surgery for ICH (ENRICH), and blood pressure control (OPTIMAL BP). We derived benefit per hundred treated (BPH, same as absolute risk reduction) and NNT using four Permutation Methods (CMH test with tied pairs ignored, divided in half, assigned by NIHSS outcome, and by better than model expectations) and three Joint Outcome Table Methods (Multi-sampling, Min-Max, and Expert Panel).

Results:
The net BPH and NNT values derived for each trial using each method are shown in the Table. Overall, the magnitude of treatment effect estimates rendered by Permutation methods were substantially lower than by Joint Outcome methods Table methods. In 4 of 8 trials, Permutation method estimates were lower than dichotomous estimates – a biologic impossibility. Among the automatic Joint Outcome Table Methods, the repetitive Multi-sampling technique yielded mildly lower estimates than the algorithmic Min-Max technique.

Conclusions:
Permutation (Cochran–Mantel–Haenszel) ordinal NNT derivation methods systematically underestimate treatment benefit magnitude due to bias towards the null from calculation-related nondifferential misclassification. Joint Outcomes Table methods may be preferred for future clinical trials that report net NNT for ordinal outcomes.
Abstract WMP50: Stroke survivors face greater social risks than adults who have not had a stroke: results from a nationwide study
Authors: Skolarus Lesli , Bi Ran , Lin Chun Chieh , Hassani Sara , Curran Yvonne , Burke James
Published: January 2025

Background:
Integrating social and medical care is one strategy to promote health equity. Yet, little is known about the prevalence of health-related social risks (social risks) among stroke survivors. We sought to determine the prevalence of social risks among stroke survivors and compare this to older adults who have not had a stroke.

Methods:
We conducted a cross-sectional analysis of community-dwelling older adults (age ≥ 65) from the National Health and Aging Trends Survey. Six core social risks were examined: medical financial needs, utility financial needs, housing, nutrition, social isolation, and transportation. We used a Poisson regression model to explore the association of social risks and history of stroke, accounting for sociodemographic factors (age, sex, race/ethnicity, education, income, rurality) and comorbidities.

Results:
Of 5834 older adults, 673 (weighted percentage, 8.68%) were stroke survivors. The most prevalent social risks were social isolation and nutrition (Figure). Stroke survivors were more likely to report social risks compared to older adults without a history of stroke (54.3% vs. 40.2%, p<0.01). Stroke survivors reported higher social needs, 0.92 (95% CI 0.78, 1.06) compared to those without a history of a stroke 0.61 (95% CI 0.57, 0.65, p<0.01). In adjusted models (Table), female sex (coeff 0.14, 95% CI 0.05, 0.23, p<0.01), Black race (coeff 0.36, 95% CI 0.22, 0.49, p<0.01), lower-income (coeff -0.18, 95% CI -0.2, -0.15, p<0.01), comorbidities (coeff 0.1, 95% CI 0.07, 0.14, p<0.01), and history of dementia (coeff 0.14, 95% CI 0.01, 0.27, p=0.04) were independently associated with social risks. History of stroke was not independently associated with social risks (coeff 0.06, 95% CI -0.08, 0.2, p=0.39).

Conclusion:
Social risks are common amongst older adults generally, and 35% more common still among stroke survivors. Social risks among older adults are more strongly influenced by sex, race, income and comorbidities rather than a history of stroke itself. Strategies to address social risks may help reduce disparities related to sex, race, and income, including among stroke survivors.
Abstract WMP56: Getting To The Heart of Stroke
TM
: Novel American Heart Association Initiative Which Increases Identification Of Stroke Etiology And Use Of Evidence-Based Post-Stroke Evaluation By Strengthening Neurology And Cardiology Collaboration
Authors: Witt John , Baird Alexandra , Schneider Alexander , Bailey Alison , Lakkireddy Dhanunjaya , Jauch Edward , Thomas Kathie , Beon Chandler , Arnold Egloff Shanna , Stergar Lindsay , Orndorff Kevin , Harper Russ , Armstrong Megan , Manoukian Steven
Published: January 2025

Background:
Nearly one million individuals in the U.S. experience ischemic stroke annually and one-year recurrent stroke risk may exceed 10%. The American Heart Association (AHA) Get-With-The-Guidelines-Stroke® Registry (GWTG-S) suggests that more than 40% of patients with stroke are discharged with a cryptogenic or undocumented etiology which may lead to suboptimal secondary prevention. Consequently, improved neurology and cardiology collaboration and evidence-based post-stroke evaluation may help identify stroke etiology, reduce recurrences and improve outcomes.

Methods:
In 2022, the AHA, in collaboration with HCA Healthcare and HCA Healthcare Foundation, designed and launched Getting to the Heart Of Stroke
TM
in 10 HCA Healthcare advanced stroke centers (GTTHOS) to improve neurology and cardiology collaboration, evidence-based post-stroke diagnostic evaluation and assessment of social determinants of health and barriers to care. Components included a learning collaborative model, virtual performance improvement consultations, Plan-Do-Study-Acts, multidisciplinary teams and performance improvement feedback. This analysis compared GTTHOS centers to the rest of HCA Healthcare’s GWTG-S centers (Non-GTTHOS; n=112) at baseline (2022) and follow-up (2023), using custom and existing GWTG-S metrics.

Results:
At follow-up, GTTHOS documented higher stroke etiology rates (58.06% vs. 48.63%), lower cryptogenic stroke (31.01% vs. 34.89%) and lower undocumented stroke etiology (10.93% vs. 16.48%)(all vs. baseline; p<0.0001). GTTHOS also demonstrated significantly increased use of evidence-based post-stroke diagnostic evaluation, including intracranial vascular and carotid imaging, echocardiography, short-term and extended (surface, implantable) cardiac monitoring. Lastly, GTTHOS documented significantly higher stroke etiology rates, lower cryptogenic stroke, lower undocumented stroke etiology and higher rates of several components of evidence-based post-stroke diagnostic evaluation at follow-up vs. Non-GTTHOS (Table; Figure 1, 2).

Conclusion:
In this novel AHA initiative, assessed in over 100 U.S. centers, Getting to the Heart Of Stroke
TM
is associated with improved determination of stroke etiology and use of evidence-based post-stroke diagnostic evaluation. These findings suggest that the initiative, which includes improved neurology and cardiology collaboration, may contribute to improved diagnosis of stroke etiology, improve secondary prevention and clinical outcomes.
Abstract WMP62: Optimizing the Approach to Calculating CST Lesion Load for Understanding Motor Outcomes
Authors: Williamson Brady , Behymer Tyler , Cramer Steven
Published: January 2025

Introduction:
Corticospinal tract (CST) lesion load (LL) based on a CST template is commonly used as a predictor of motor outcomes after stroke, but the optimal approach is still unclear. We compared 4 LL metrics and 3 CST templates to explore which approach explains the most variance in motor outcome, hypothesizing that strongest results would be found using elderly subjects to create the CST template.

Methods:
Data from the ENIGMA dataset were studied, with n=221 after exclusion for data quality; missing data; and bilateral, brainstem, or cerebellar stroke (median=62 years). The four lesion load metrics were 1) grid split of the CST into 16ths using (Fig 1A) and assessing the number of sections with > 5% injury, 2) radial split of the CST into 16ths (Fig 1B) and assessing the number of sections with >5% injury, 3) computing the LL per slice weighted by the inverse diameter of the CST (WLL, Fig 1C) then taking the AUC across all slices, and 4) taking the WLL value from the maximally affected slice (Max-WLL). The three tract templates were: 1) a previously published template derived from 12 healthy participants (31-68 years), 2) a template derived from 1052 participants from the Human Connectome Project and 3) a template created using a subset of 326 subject ages 50-80 years from the HCP Aging (HCPA) study. Bayesian ordinal regression models were used to look at relationship between motor outcome and the LL for each method, controlling for M1 LL, corpus callosum LL, age, lesion side, and lesion volume.

Results:
Heatmaps show the most frequently injured CST slice (Fig 2A) and lesion location (Fig 2B). Modeling with Max-WLL of the HCPA template was the optimal approach, explaining 40% (95%CI: 29%, 48%) of variance in motor score, with Max-WLL accounting for 52.4% of the model’s explanatory value (95%CI: 32%, 63%) (Fig 3C). The effect of LL was nonlinear (Fig 3B). The R
2
for the other methods was 35% (Grid Split), 35% (Radial Split) and 39% (WLL). Results remained significant whether the motor outcome was impairment or function.

Discussion:
Results are consistent with recent work showing Max-WLL is optimal for explaining motor outcomes, and with the fact that CST diameter and integrity changes with age. Findings indicate that an age-matched template better captures CST anatomy in elderly patients, and that focusing on the brain slice with maximal CST injury provide the optimal approach to calculating CST injury for understanding motor outcomes after stroke.
Abstract WMP63: Performance of RAPID SDH for detection of both Acute and Chronic Subdural Hematomas
Authors: Heit Jeremy , Haerian Hafez , Copeland Karen , Honce Justin
Published: January 2025

Introduction:
Subdural hematomas (SDHs) are increasing in prevalence and are one of the most common pathologic processes necessitating neurosurgical intervention. Acute SDHs may require urgent surgery and detection of chronic SDHs is of increasing importance due to recent data demonstrating successful management with middle meningeal artery embolization. The prognosis for SDH patients varies significantly based on the hematoma's size, the patient's age, and the promptness of treatment. Rapid SDH is a fully automated software with FDA clearance for triage and notification of hemispheric SDH from non-enhanced head CT (NCCT) images. We determined the accuracy of Rapid SDH for both acute and chronic SDH compared to gold standard expert readers.

Methods:
In this retrospective, multicenter study, performance of the Rapid SDH software was assessed based on the consensus of three expert neuroradiologists who independently reviewed each scan to confirm the presence and subtype of SDH blinded to the software output. Scans with SDH with volumes <1 mL and patients under the age of 21 were excluded.

Results:
A total of 313 cases, including a consecutive series of patients that was enriched for SDH, were identified (mean age, 63 years ± SD 22; 189 male, 111 female, 13 unknown). Three cases were excluded from the analysis (one for volume <1 ml, two for scan quality). Of the 310 remaining, 157 were positive for SDH (48 acute, 47 chronic, 44 mixed, and 18 isodense) and 153 were negative for SDH per consensus of 3 expert neuroradiologists. Performance of the software, based on the neuroradiologist gold standard, demonstrated a sensitivity of 92.4% (95% CI: 87.1, 95.6) and a specificity of 98.7% (95% CI: 95.4, 99.6) for the detection of SDH. The sensitivity for chronic SDH (91.5% 95% CI 80.1-0.96.6) did not differ from acute/subacute SDH (92.7% CI 86.3-0.96.3). The median processing time was approximately 45 seconds.

Conclusion:
The results confirm that automated imaging analysis using Rapid SDH provides fast and accurate detection of both acute and chronic SDH on NCCT. Use of this software has the potential to expedite SDH diagnosis and treatment.
Abstract WMP67: Circadian Variation In Collateral Status: The HERMES Collaboration
Authors: Tariq Muhammad Bilal , Brown Scott , Liebeskind David , Tiedt Steffen , Lun Ronda , Albers Gregory , Mun Katherine , Majoie Charles , Demchuk Andrew , Jovin Tudor , Mitchell Peter , Campbell Bruce , Bracard Serge , guillemin francis , Muir Keith , White Phil , Dippel Diederik , Hill Michael , Goyal Mayank , Saver Jeffrey
Published: January 2025

Background:
Prior studies have demonstrated that the incidence of stroke and rate of infarct progression varies across the 24-hour cycle and that circadian rhythm is associated with the brain’s response to reperfusion and neuroprotection. However, the pathophysiology of this variation is poorly understood. In this study we assessed changes in collateral status with time of day as a possible mechanism behind this variation.

Methods:
Using data from the 7 randomized EVT trials in the HERMES collaboration, patients with analyzable baseline CT angiograms were selected. Presenting collateral status on CTAs was rated using the Regional Collateral Score (rCS). The effect of time of onset (last known well) and time of scan on collateral status was assessed. Time of day was analyzed as: 1) binary day-night (23:00–06:59/07:00–22:59); 2) 4-hour intervals (23:00–02:59/03:00–06:59/07:00–10:59/11:00–14:59/15:00–18:59/19:00–22:59) and 3) a continuous variable as per Consortium International pour la Recherche Circadienne sur l’AVC recommendations.

Results:
Among 1250 patients with LVOs, 1086 (86.9%) had daytime and 164 (13.1%) had night-time stroke onset. Baseline demographic and clinical features of patients that differed (Table 1) were night-time onset patients were younger (62.0 vs 67.1 years), less often had highly severe (NIHSS>16) deficits (43.6% vs 56.3%), had longer onset-to-arrival (186 vs 122 minutes), and longer onset-to-imaging (218 vs 159 minutes). In multivariable analysis, categorizing based on last known well time, there were no significant difference in rCS score by night vs day (7.5±2.0 vs 7.4±2.3 p=0.99) or by 4-hour intervals (7.8±1.9 vs 7.3±2.1 vs 7.4±2.2 vs 7.5±2.2 vs 7.5±2.3 vs 7.1±2.4 p=0.24) (Figure 1). Similarly, categorizing by scan time, there were no significant differences in rCS score by night vs day (7.3±2.3 vs 7.4±2.2 p=0.60) or by 4-hour intervals (7.2±2.4 vs 7.6±2.0 vs 7.3±2.2 vs 7.4±2.1 vs 7.5±2.3 vs 7.6±2.3 p=0.22) (Figure 1). The relationship between continuous time and rCS mapped by LOESS regression also did not indicate substantial rCS variation with time of onset (Figure 2).

Conclusion:
Our study does not demonstrate a strong relationship between time of day and regional collateral score. This was at least partially driven by a ceiling effect as most patients had good collateral scores. Further studies to identify patient and imaging characteristics that may explain the relationship between circadian variation of stroke outcomes are needed.