bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP7: Somatosensory Evoked Potentials and Dramatic Recovery After Mechanical Thrombectomy in Patients With Acute Ischemic Stroke and Anterior Large Vessel Occlusion
Authors: Martinez-Piñeiro Alicia , Almendrote Miriam , Ramos-Fransi Alba , Lucente Giuseppe , Lopez-Cancio Elena , Perez de la Ossa Natalia , Remollo Sebastian , Castaño Carlos , Coll-Canti Jaume , Davalos Antoni
Published: June 2021

Hypothesis:
Somatosensory evoked potentials (SEPs), as surrogate of cerebral blood flow, may predict immediate and long term clinical outcome in patients with acute ischemic stroke undergoing mechanical thrombectomy.

Methodology:
Median nerve SEPs were monitored before and continously during mechanical trhombectomy in acute ischemic stroke patients with proximal anterior large vessel occlusion. The target signal was the patency of the N20 wave ipsilateral to the stroke site. Dramatic recovery was defined as improvement ≥ 10 or NIHSS score 0-1 at 24 hours and good functional outcome as modified Rankin scale 0-2 at 90 days.

Results:
A total of 41 patients were monitored with SEPs. Six patients were excluded because of traces artifacts. At the beginning of the procedure, patent N20 was observed in 25 patients and absence of N20 wave in 10 patients. Age, gender, median NIHSS score (17 vs 17), site of vessel occlusion, IV tPA use, ASPECTS score and onset-to-groin puncture time were comparable between patients with patent and absent N20 wave. Patent N20 group showed better median NIHSS score at 24 hours (6 [2-18] vs 18 [11-24], p=0.031) and a no significant trend to a higher rate of dramatic recovery (52% vs 25%, p=0.087). At the end of the procedure, patent N20 was found in 25 patients (3 recovered N20 and 3 lost N20 wave). Complete revascularization (TICI 2b,3) was achieved in 22/25 patent N20 group and 4/10 no patent N20 group. Patent N20 at the end of the procedure was significantly associated with dramatic recovery (60% vs 0%, p=0,001) and good functional outcome (68% vs 0%, p=0,001)

Conclusions:
SEPs recording is a non-invasive and feasible test that provides real time data in the angiosuite, even in patients under general anesthesia in which neurological deficit cannot be evaluated. Patency of SEP at the beginning but especially at the end of the procedure is related with immediate and long term outcome, despite achieving complete revascularization.
Abstract TP71: Interruption of Antiplatelet and Anticoagulant Therapy Does Not Increase Risk of Recurrent Stroke in Patients with Left Ventricular Assist Devices
Authors: Tsai Jenny Peih-Chir , Barrett Christopher , Schwartz Neil E , Banerjee Dipanjan
Published: June 2021

Introduction:
Left ventricular-assist devices (LVAD) have increased survival and quality of life of patients with heart failure. Patients with LVAD have increased risks of ischemic and hemorrhagic cerebrovascular events due to device thrombosis and combined use of antiplatelet and anticoagulant agents. The safety of transient interruption of combined antithrombotic therapy after stroke is unknown.

Hypothesis:
Time to resumption of combined antiplatelet and anticoagulant therapy after stroke is not associated with the incidence of recurrent cerebrovascular event.

Methods:
We defined the study cohort of patients who received an LVAD using ICD-9 codes. We obtained data for patients with new cerebrovascular events while on a Heartmate-II or Heartware LVAD, and excluded those deceased from the initial event. We divided patient-events into two cohorts based on the index event: ischemic (TIA, stroke) or hemorrhagic (all intracranial hemorrhages, ICH). We used Fisher’s exact test to assess the association between recurrent ischemic event or ICH and time off combined antithrombotic therapy. We pre-specified variables for adjustment in the logistic regression analysis: age, cardiovascular risk factors, LVAD model, indication and endpoint, NIHSS score, INR and LDH levels, and baseline and change in antithrombotic therapy.

Results:
The study included 48 patient-events between 2011 and 2016: 23 (48%) were ischemic (9 (40%) TIA and 14 (60%) infarcts) and 25 (52%) hemorrhagic. The ischemic event cohort had 9 (39%) recurrences, including 6 (67%) ischemic and 3 (33%) ICH. Median time to recurrence was 118 (IQR 78-388) days. All patients continued on antiplatelet, and maximum time off anticoagulant was 2 (median 0) days. Time off combined therapy was not associated with ischemic (p=0.43) or hemorrhagic recurrence (p=1.00). The ICH cohort had three (12%) recurrences: 1 (33%) ischemic and 2 (67%) hemorrhagic. Median time to recurrence was 158 (IQR 32-586) days. Median time off combined therapy was 7 (0-15) days, and not associated with ischemic (p=0.43) or hemorrhagic recurrence (p=0.83).

Conclusion:
In patients with LVAD, transient interruption of combined antithrombotic therapy after stroke is not associated with increased risk of recurrent cerebrovascular events.
Abstract TP77: New treatment
Authors: Shimamura Munehisa , Nakagami Hironori , Wakayama Kouji , Kawano Tomohiro , Mochizuki Hideki , Morishita Ryuichi
Published: June 2021

Background and purpose:
We previously showed that stimulation of RANKL (receptor activator of nuclear factor-B ligand)/ RANK (receptor for RANKL) signal with novel RANKL-based partial peptide, MHP1, worked as anti-inflammatory in microglia and macrophages without induction of osteoclast activation, but the effects of systemic injection of MHP1 in ischemic brain is still unclear. Here, we examined the effects of systemically injected MHP1 in ischemic brain.

Methods:
FITC-conjugated MHP1 was injected via jugular vein 4 hrs after transient middle cerebral artery occlusion (tMCAo) in C57BL6J mice to check whether MHP1 could penetrate into infarct parenchyma. To examine whether MHP1 has therapeutic effects, MHP1 was injected intravenously (IV) followed by successive subcutaneous injection with Alzet pump beginning at 4 or 6 hrs after tMCAo. The effects of MHP1 for osteoclast activation in the radial bone in paralyzed upper arm were examined by TRAP staining.

Results:
Immunohistochemistry for FITC showed that MHP1 could successfully penetrated into infarct parenchyma 5 min after IV injection of MHP1, but the penetrated MHP1 was not observed 1 hr after injection. These results indicated that MHP1 should be administered continuously to achieve successive penetration into infarct parenchyma. The mice treated with MHP1 showed less neurological severity score and infarct volume at 48 hrs after tMCAo even when the treatment was started at 6 hrs after MCAo. TRAP staining showed that osteoclast activation in paralyzed radial bone was inhibited in MHP1-treated mice, suggesting that MHP1 could prevent osteoclast activation as well as ischemic injury.

Conclusion:
Systemically injected MHP1 could successfully penetrated into infarct parenchyma and prevent exacerbation of paralysis and infarct size after tMCAo. Although further studies for improvement of its stability are needed, MHP1 might be a novel agent to treat ischemic brain.
Abstract TP80: Panaxatriol Saponins Attenuates Blood-brain Barrier Disruption and Promotes Angiogenesis After Ischemic Stroke in Rats
Authors: Yang Hui , Hui Zhen , Sha Du Juan , Xu Yun
Published: June 2021

Background:
The induction of angiogenesis and maintain the integrity of the blood brain barrier (BBB) after stroke may enhance neurorestorative processes. Panaxatriol Saponins (PTS), extracted from traditional Chinese herb Panaxnotoginseng, could noticeably prevent BBB disruption and promote angiogenesis in rodent stroke model.

Methods:
Middle cerebral artery occlusion (MCAO) model were applied to mimic acute stroke in vivo. Ischemic infarct volume and neurological functions were evaluated through 2,3,5-triphenyltetrazolium chloride (TTC) staining and Longa Scores (LS) respectively. The micro-PET scan was adopted to assess cerebral perfusion; evans blue extravasation assay was used to test BBB permeability; real time PCR and Western blot were used to evaluate the level of vascular growth factors, pro-inflammation factors, the components of Sonic hedgehog (Shh) pathway and NF-κB pathway. Enzyme Linked Immunosorbent Assay (ELISA) was used to detect the levels of pro-inflammation factors in the brain. The capillaries density in ischemic penumbra and tight junction in BBB were measured by immunofluorescence staining.

Results:
PTS treatment improved neurological function and reduced infarct volume in MCAO-rats. The result of micro-PET scan indicated that PTS could significantly enhance cerebral perfusion after MCAO operation. Treatment of PTS significantly attenuated BBB destruction. PTS could significantly increase the VEGF, Ang-1, VEGFR-2, Tie-2, CD31 and α-SMA mRNA expression at 3 d and 7 d after MCAO compared to vehicle group. Moreover, the expression levels of inflammation factors were decreased after PTS treatment. The co-immunofluorescence staining of α-SMA and Brdu with CD31 respectively showed that PTS promotes angiogenesis and endothelial cell proliferation after MCAO. Meanwhile, co-immunofluorescence staining of Claudin-5, Occludin and ZO-1 with CD31 respectively showed that PTS could protect tight junction from ischemia/reperfusion injury. PTS could also activate Shh pathway and inhibited NF-κB pathway.

Conclusions:
PTS alleviated ischemic stroke injury through attenuates blood-brain barrier disruption and promotes angiogenesis. PTS could be a potential medication for combating ischemic brain injury.
Abstract TP94: Mesenchymal Stromal Cells Behave Differently When Exposed to Medications Commonly Prescribed to Stroke Patients
Authors: Satani Nikunj , Yang Bing , Nghiem Duyen M , Xi Xiaopei , Gee Adrian P , Aronowski Jaroslaw , Savitz Sean I
Published: June 2021

Background:
As a promising investigational therapy for stroke recovery, mesenchymal stromal cells (MSCs) are in various stages of clinical trials. MSCs may promote recovery through cytokine release and immunomodulation. Stroke patients typically are treated with antiplatelets and medications for hypertension and hyperlipidemia. We explored the effect of commonly prescribed drugs at physiological concentrations on MSCs.

Methods:
Clinical grade bone marrow MSCs from healthy donor at passage 2 were thawed and re-suspended in serum free media. Monocytes (Mo) were isolated from peripheral blood of healthy humans. MSCs and Mo were cultured alone as well as in co-culture and exposed to simvastatin, atenolol, losartan, captopril, or aspirin. They were also exposed to high glucose (upto 40mM) to simulate hyperglycemia. At 24 hours of incubation, media was collected and TNF-α concentration was measured, as an index of immunomodulation of Mo by MSCs. Cell viability was also measured (using MTT assay and flow cytometry).

Results:
There were significant effects of all drugs on viability of MSCs but with no impact on Mo. More importantly, Losartan (dose independent), Simvastatin and Atenolol (dose-dependent) reduced the viability of MSCs even at the pharmacologically relevant concentrations (Fig 1). High glucose had no effect on viability of MSCs or Mo. TNF-α secretion from co-culture of MSCs and Mo at 24 hours showed differences at very high doses of aspirin (2-fold increase), atenolol (0.5 fold decrease), and glucose (0.5 fold decrease) (data not shown). However, these high concentrations are unlikely to be achieved pharmacologically in plasma of patients treated with these drugs.

Conclusion:
Exposure of MSCs to clinically relevant drugs can alter their viability and function. Our results suggest that stroke trials involving use of intravenous MSCs should consider the differential impact of commonly prescribed medications on MSCs function.
Abstract WMP100: Topographical Distribution of Lacunes in Cerebral Amyloid Angiopathy and Deep Hypertensive Intracerebral Hemorrhage
Authors: Pasi Marco , Boulouis Gregoire , Fotiadis Panagiotis , Charidimou Andreas , Auriel Eitan , Aley Kellen , Ayres Alison , Schwab Kristin M , Goldstein Joshua , Rosand Jonathan , Viswanathan Anand , Pantoni Leonardo , Greenberg Steven M , Gurol Edip
Published: June 2021

Background/Aims:
To evaluate whether the burden of lacunes located at deep and lobar brain regions, would differ between intracerebral hemorrhage patients (ICH) with cerebral amyloid angiopathy (CAA) vs patients with strictly deep cerebral microbleeds (CMB) and ICH (Deep HTN-ICH).

Methods:
We defined lobar and deep lacunes similar to the topographic distribution used for ICH and microbleeds. We then compared their distribution between CAA and Deep HTN-ICH patients. The independent associations of lacune location (lobar vs deep) with diagnosis of CAA-ICH and Deep HTN-ICH were evaluated using multivariable models. The relationship between lobar and deep lacunes and WMH volume was evaluated using partial correlation analyses adjusting for age and by means of a validated visual scale.

Results:
In our cohort of 316 ICH patients, lobar lacunes were more commonly present in CAA (20.4% vs 5.7% in Deep HTN-ICH, p<0.001; see figure) while deep lacunes more frequent in Deep HTN-ICH patients (15.2% vs 2.1%, p<0.001; see figure). After correction for demographics, clinical and neuroimaging markers of SVD, lobar lacunes were associated with CAA diagnosis (p=0.023), while deep lacunes with Deep HTN-ICH (p<0.001). Lobar lacunes in 80% of the cases were at least in contact with WMH and after adjustment for age they were highly correlated to WMH volume (
r=0.52,
p<0.001).

Conclusions:
Lobar lacunes are associated with CAA whereas deep lacunes are more frequent in patients with Strictly deep CMBs and ICH, they can thus be clinically useful in the appropriate context. Lobar lacunes seem to have a close relationship with WMH suggesting a possible common origin.
Abstract WMP102: Prevalence and Natural History of Superficial Siderosis: A Population-based Study
Authors: Pichler Michael , Flemming Kelly , Rabinstein Alejandro , Brown Robert , Kantarci Kejal , Vemuri Prashanthi , Mielke Michelle , Knopman David , Jack Clifford , Petersen Ronald , Graff-Radford Jonathan
Published: June 2021

Introduction:
Cortical superficial siderosis (cSS) refers to deposition of blood breakdown products along the cerebral cortex, causing characteristic staining patterns seen with iron-sensitive MRI techniques. Cortical superficial siderosis is a relatively rare disorder, but has been linked to cerebral amyloid angiopathy and Alzheimer’s disease. The objective of this study was to determine the frequency and natural history of cSS in the general elderly population.

Methods:
MRI scans from the Mayo Clinic Study of Aging (MCSA), an ongoing population-based study of elderly residents in Olmsted County, Minnesota, were reviewed by neuroradiologists. Participants with cSS were identified based on linear pattern of hypointensity on gradient recalled echo imaging consistent with cSS. Exclusion criteria were: 1) MRI findings not consistent with cSS or 2) alternative explanation for MRI findings (such as aneurysmal subarachnoid hemorrhage, intracranial surgery, or trauma). Additional data abstracted included extent of cSS, presence of cerebral microbleeds, and clinical outcome.

Results:
Eleven out of 1,441 participants had MRI scans showing cSS (0.8%). When stratified by age, the frequency was 0.4% in those 50 to 70 years old and 1.1% in those over 70 years old. Six participants had only focal involvement of cSS (restricted to three or fewer sulci) and five had disseminated involvement (affecting more than three sulci). Microbleeds were seen in four of five (80%) participants with disseminated cSS, but none with focal cSS. Five participants (2 focal, 3 disseminated cSS) had follow up MRI scans, with an average follow up of 25 months. There was no further hemorrhage in those with focal cSS. However, all three participants with disseminated cSS experienced additional hemorrhage: one with new microbleeds, one with new microbleeds and lobar hemorrhage, and one with sulcal subarachnoid hemorrhage and lobar hemorrhage.

Conclusion:
Although rare, cSS may be encountered in the general elderly population. Extent of involvement of cSS and concomitant microbleeds may be important risk factors for progression of disease and intracerebral hemorrhage. The clinical significance of focal cSS occurring in the absence of microbleeds requires further investigation.
Abstract WMP115: Thrombolysis and Thrombectomy in Pediatric Ischemic Stroke
Authors: Ess Kathryn , Ouyang Bichun , Waldner Nick , Dafer Rima , Conners James , Cherian Laurel , Osteraas Nicholas , Song Sarah
Published: June 2021

Introduction:
Stroke is a devastating disease at any age. There are few studies on utility of intravenous thrombolysis (tPA) or intra-arterial thrombectomy (IAT) in pediatric acute ischemic stroke (AIS).

Hypothesis:
To describe and compare clinical outcomes of pediatric AIS patients who did and did not receive tPA+/-IAT.

Methods:
We retrospectively reviewed all pediatric AIS cases, aged 0-17, from the 2006-2010 Nationwide Inpatient Survey, a 20% stratified sample of all U.S. community hospitals. Demographics, outcomes, cost of stay, and comorbidities were assessed.

Results:
Overall, 20,587 patients were analyzed. Mean age was 6.0 years (SD 13.9); female 43.9%; white 47.7%. Of those, 198 patients received intervention: 169 tPA, 5 IAT, and 24 tPA+IAT. Treated patients were older (10.0 years vs 5.9 years, p<0.0001). Mortality for pediatric AIS patients was 7.8%; 13.8% in tPA patients compared to 7.7% in the untreated. No deaths in the IAT group. Non-treated patients were more likely to be discharged home than those receiving tPA+/-IAT (67.8% vs. 47.5%, p<0.0001). Cost for treated patients was higher ($200,346 vs. $123,015, p=0.01). Intracerebral hemorrhage (ICH) was more common in treated patients (10.1% vs. 3.8%, p<0.0001). Comorbidities included Moyamoya disease (12.4%), cardiac valvular disease (6.6%), and sickle cell disease (6.5%). The treated group had higher prevalence of pneumonia/influenza (17.2% vs. 7.6%, p<0.0001), procoagulable conditions (15.2% vs. 2%, p<0.0001), and cardiac valvular disease (15.2% vs. 6.5%, p<0.0001).

Conclusions:
In the pediatric AIS population, tPA was associated with increased mortality. Treatment with tPA+/-IAT was associated with decreased discharge home, increased cost, and higher prevalence of ICH. Prevalence of ICH is not explained by the presence of Moyamoya or sickle cell as those patients were less likely to receive treatment. Limitations of this study include small numbers of treated patients, lack of data on stroke severity or functional outcome, and data from years prior to newer thrombectomy devices. Studies of AIS treatment in adults cannot necessicarily be extrapolated given the difference in etiologies of pediatric AIS. Pediatric AIS is on the rise, so more research for effective treatment is necessary.
Abstract WMP116: The Effects of Immediate Treatment with Inter-alpha Inhibitor Proteins on Apoptosis in Neonatal Rats Exposed to Hypoxic-ischemic Injury
Authors: Nakada Sakura , Chen Xiaodi , Lim Yow-Pin , Stonestreet Barbara S
Published: June 2021

Background:
Hypoxia-Ischemia (HI) is a condition in which the brain is deprived of adequate blood and oxygen supplies, resulting in a variety of neurodevelopmental morbidities in newborns. Inter-Alpha Inhibitor Proteins (IAIPs) are immunomodulatory proteins that have anti-inflammatory properties in systemic inflammatory disorders. The neuroprotective effects of treatment with IAIPs on apoptosis resulting from HI-related injury have not been examined yet.

Objective:
To investigate the effects of systemic treatment with IAIPs on apoptosis in HI-exposed neonatal rats.

Design/Methods:
Postnatal day 7 rats were randomly assigned to one of three groups: Placebo-Sham (PL-Sham, n=8), Placebo-HI (PL-HI, n=8) and IAIP-HI (n=8) groups. The PL-Sham group was not exposed to HI and received placebo intraperitoneally (0.9% NaCl); the PL-HI group was exposed to HI and received placebo (0.9% NaCl); the IAIP-HI group was exposed to HI and received IAIPs treatment (30 mg/kg). The Rice-Vannucci model was utilized to induce HI-related brain injury: unilateral carotid artery ligation followed by hypoxia (90 min in 8% O
2
). Rat sex was recorded. Placebo or IAIP treatment was given at 0, 24 and 48 hours after HI, and brains were perfused and fixed at 72 hours. Fixed brain tissues were immunohistochemically stained with TUNEL apoptotic cellular markers. Apoptotic cells were counted without knowledge of the group assignment using the StereoInvestigator 10.0, Fractionator probe (MBF Bioscience).

Results:
There were more TUNEL positive cells in the PL-HI group than in the PL-Sham group overall (female+male) as well as in males in the cortex, total hemisphere and hippocampus (all
P
<0.05), but not in females (
P
=0.11,
P
=0.30 and
P
=0.12, respectively). There appeared to be less apoptosis in the male IAIP-treated HI rats compared with the male placebo-treated HI rats (
P
=0.29 for hemisphere and cortex,
P
=0.51 for hippocampus).

Conclusion:
Apoptosis is significantly increased after HI in the total hemisphere, cortex, and hippocampus of male neonatal rats, but not in females. Further investigation is needed to determine the neuroprotective effects of IAIPs on apoptosis in HI-exposed neonatal rats, although preliminary data suggests a protective trend for male rats.
Abstract WMP120: Does ICH Volume Affect Onset to Arrival Time?
Authors: Meyer Dawn , Hailey Lovella , Mortin Melissa , Nguyen David , Pirastehfar Mohshen , Ho James , Narula Rajiv , Rapp Karen , Agrawal Kunal , Huisa-Garate Branko , Modir Royya , Hemmen Thomas , Meyer Brett
Published: June 2021

Background:
ICH is a disease of high mortality. Increased hematoma volume has been associated with increased NIHSS severity and worse outcome. The purpose of this study was to determine if hematoma volume was correlated with time from symptom onset to time of hospital arrival.

Methods:
We conducted a review of consecutive acute ICH patients who were treated at UC San Diego from an IRB approved, prospectively collected UC San Diego Stroke Registry (1/2003-07/2016). All patients that presented as a “code stroke” within 12 hours and had ICH as the primary diagnosis were included in the analysis. Patients were allocated to time quartiles from symptom onset to arrival and compared between those quartiles for baseline demographic variables. A correlation matrix was built to assess variables that were correlated with ICH volume (mL). Variables with a p >0.10 were then included in a logistic regression to model.

Results:
The overall sample included 316 patients. Time from onset to arrival ranged from 25-720 minutes. The baseline demographics were significantly different amongst the time quartiles for: 1) history of atrial fibrillation (p=0.04); 2) current alcohol use (0.04); 3) and NIHSS (p=0.006). Patient in Q3 had the highest a-fib rates (20.5%). NIHSS was highest in Q1. ICH volume was significantly and positively correlated with age, history of HTN, current ETOH abuse, current SBP, and 90 day mRS (all p<0.05). ICH volume was not significantly correlated with time of arrival.

Conclusion:
This study supports the previous data of ICH volumes relationships to outcome. Other variables may be considered in ICH outcome scales to improve prognosis.
Abstract WMP25: Mean Platelet Volume as a Predictor of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage
Authors: Ray Bappaditya , Tinsley Lane , Yearout Lori K , Thompson David M
Published: June 2021

Introduction:
Mean platelet volume (MPV) is a common platelet index that estimates average platelet size. In retrospective cohorts, MPV is reported to be higher, on average, in patients who have experienced acute cardiovascular or cerebrovascular events. Aneurysmal subarachnoid hemorrhage (aSAH) is often associated with increased thrombogenic state due to reactive platelets resulting in delayed cerebral ischemia (DCI).

Hypothesis:
We assessed whether trends in MPV over the first 21 days after aSAH predicts occurrence of DCI.

Methods:
The present study enrolled a prospective cohort of 47 patients with aSAH. Clinical (H&H, WFNS) grades and daily MPV was recorded. Patients surviving atleast 7 days following aSAH were included for analysis to determine temporal trend of MPV. Mixed linear regression model was used to compare MPV trends between groups defined by clinical grades of varying severity. Segmented linear regression analysis was performed to identify transition point for patients developing DCI in comparison to those without DCI

Results:
Average age of cohort was 53.3±13.2 years with 68% women. Thirty-five of the 47 (74.5%) were H&H I-III as compared to 21/47 (44.7%) with WFNS 4-5. Thirty-two patients developed DCI. Baseline MPV was no different (~10.5fL) among patients with different clinical grades. In 32 patients who developed DCI, a transition point at 3 days was identified prior to which MPV increased by 0.13fL/day (95% CI 0.04, 0.23; p=0.0047) followed by a decline of 0.03fL/day (95% CI 0.02, 0.04; p=0.0006). Similar trend was not seen in those without DCI. Rate of decline in MPV were steeper among patients with H&H I-III and WFNS 1-3 as compared to those with H&H IV-V and 4-5 [0.26fL/day; 90% CI 0.004, 0.048, p=0.051 and 0.23fL/day; 90% CI 0.003, 0.042, p=0.06 respectively].

Conclusion:
Rise in MPV during the first 3 days after aSAH with DCI followed by a decline indicates release of larger platelets after aSAH and possible association with DCI. Absence of declining trend MPV among higher clinical grade aSAH patients suggests persistence of reactive platelets in circulation.
Abstract WMP37: MicroRNA-29a Protects Against Cerebral Ischemia and Reperfusion Injury by Targeting NADPH Oxidase 4
Authors: Tuo Yong-Hua , Liu Zhong , Feng Lei , Shi Zhong-Song
Published: June 2021

Background:
MicroRNA-29a (miR-29a) is involved in regulating cerebral ischemia process, but its underlying mechanism is unclear. We previously showed that inhibition of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX4) pathway improves the neurological outcome and increases the expression of miR-29a in transient middle cerebral artery occlusion (tMCAO) animal model. This study investigated the role of miR-29a in cerebral ischemia and reperfusion injury after mechanical reperfusion.

Methods:
The intraluminal filament tMCAO model was established in male rats with 2 hour ischemia followed by reperfusion. The expression of miR-29a and NOX4 in the infarction core and peri-infarct cortex were quantified at 0, 3, 12, and 24 hour after reperfusion. Permanent MCAO model was also evaluated after 2 hour and 24 hour ischemia. Intravenous miR-29a agomir was delivered immediately after reperfusion. Infarct volume, brain water content, neurological score, blood-brain barrier damage, and levels of miR-29a and NOX4 were determined at 24-hour after cerebral ischemia.

Results:
MiR-29a levels in the infarction core and peri-infarct cortex were significantly decreased at 3 hours after reperfusion in tMCAO group compared with the sham-operated group. The decreased levels of miR-29a lasted for 24 hours after cerebral ischemia. Dual-luciferase reporter system showed that NOX4 was the direct target gene of miR-29a. Intravenous miR-29a agomir increased the expression of miR-29a and suppressed NOX4 up-regulation in both the infarction core and peri-infarct cortex at 24-hour after ischemia compared with the tMCAO group (all p<0.05). Intravenous miR-29a agomir reduced infarct volume (24.7% ± 4.0% versus 37.8% ± 7.5%, p<0.01) at 24-hour after ischemia compared to the tMCAO group. MiR-29a agomir attenuated brain edema and reduced reperfusion-induced blood-brain barrier breakdown, resulting in improved neurological outcome (all p<0.05).

Conclusions:
MiR-29a overexpression protects against cerebral ischemia and reperfusion injury via downregulating NOX4. Infusion of miR-29a agomir immediately after reperfusion represents a novel adjunctive therapeutic strategy to improve outcome after mechanical reperfusion for acute ischemic stroke.
Abstract WMP43: Neurorestorative Therapy of Stroke in T2DM Mice With Exosomes Derived From Brain Endothelial Cells
Authors: Chen Jieli , Cui Chengcheng , Zacharek Alex , Venkat Poornima , Yu Peng , Chopp Michael
Published: June 2021

MicroRNA-126 is primarily expressed in endothelial cells (ECs), and is emerging as a key player in the pathogenesis of type two diabetes (T2DM) induced vascular damage. Stroke in T2DM increases vascular and white matter (WM) damage in the ischemic brain, and has a poor prognosis compared to non-DM stroke. In this study, we investigated the neurorestorative effects of exosomes derived from mouse brain ECs (EC-Exo) as a treatment of stroke in T2DM mice.

Methods:
Adult male BKS.Cg-m+/+Lepr
db
/J (T2DM) and db/+ (non-DM) control mice (3-4 m) were subjected to right extraluminal permanent distal middle cerebral artery occlusion (dMCAo), and intravenous injection at 3 days after dMCAo with:
1)
PBS;
2)
Liposome mimic as vehicle control (3X10
10
); 3): EC-Exo (3x10
10
); 4) Knockdown of miR-126 in EC-Exo (miR-126-/-EC-Exo, 3X10
10
); 5) Knock-in miR-126 in EC-Exo (miR-126+/+EC-Exo, 3X10
10
). Mice were sacrificed at 28 days after dMCAo.

Results:
1)
T2DM-dMCAo mice exhibit significantly decreased blood serum, brain tissue and brain-EC miR-126 expression compared to non-DM-dMCAo mice.
2)
EC-Exo contain higher levels of miR-126 than exosomes derived from other types of cells (smooth muscle cells, neurons, astrocytes and marrow stromal cells);
3)
EC-Exo treatment significantly increases axonal outgrowth and increases capillary tube formation in vitro. Compared to PBS or liposome mimic treatment groups, EC-Exo treatment of stroke in T2DM-dMCAo mice:
4)
is safe and does not appear to induce adverse side effects in physiological parameters and does not decrease lesion volume, but significantly improves neurological outcome and cognitive function after dMCAo;
5)
significantly increases axon, myelin, vessel density and increases artery diameter in the ischemic boundary zone;
6)
significantly increases perfused vessel density measured by FITC-dextran injection.
7)
miR-126-/-EC-Exo treatment significantly decreases, but miR-126+/+EC-Exo increases miR-126 expression compared to EC-Exo control.
8)
miR-126+/+EC-Exo treatment significantly improves functional outcomes when compared to miR-126-/-EC-Exo, or PBS control.

Conclusion:
Treatment of stroke with EC-Exo increases miR-126 expression and promotes neurorestorative effects after stroke in T2DM mice.
Abstract WMP45: Targeted Inhibition of the Alternative Complement Pathway Enhances Rehabilitation-Induced Cognitive and Motor Recovery in a Murine Model of Chronic Stroke
Authors: Alawieh Ali , Andersen Meredith , Adkins DeAnna L , Tomlinson Stephen
Published: June 2021

Introduction:
Activation of inflammatory cascades after stroke exacerbate acute injury and limit response to rehabilitation (rehab). The complement (C) system is a prominent component of inflammatory injury after stroke, but can also contribute to neuroprotective recovery processes. We investigated the neuroprotective effects of CR2fH, a site-targeted C inhibitor that specifically inhibits the alternative pathway and prevents amplification of the C cascade. We assessed how CR2fH affects chronic outcomes, and how acute C inhibition impacts the response to rehab therapy.

Methods:
Mice were subjected to 1hr middle cerebral artery occlusion and 15 days of reperfusion. Mice were treated with CR2fH or vehicle and then randomized to normal housing or an enriched environment (EE) to model cognitive and motor rehab. Animals were assessed for infarct volume using MRI at days 4 and 14 after injury, and for their performance on several motor and cognitive tasks. Expression of inflammatory markers in the brain was assessed using high throughput Nanostring analysis and immunostaining.

Results:
Compared to vehicle or EE only, treatment with CR2fH 90 mins after cerebral ischemia significantly reduced infarct volume and improved motor and cognitive performance up to 15 days, as assessed with mNSS scores, corner task, locomotor activity, pasta handling, and passive avoidance tasks (p’s<0.01). Less prominent, although still significant improvement was also achieved when CR2fH was administered 6 or 12 hrs. after ischemia (p’s<0.05). EE alone did not significantly reduce infarct volume or improve performance on motor tasks, but resulted in a significant improvement in cognitive performance compared to vehicle (p’s<0.05). A combination of EE and CR2fH therapy resulted in a significant potentiation of cognitive and motor recovery compared to either single intervention (p’s<0.05). CR2fH related behavioral improvements correlated with reduction in C deposition and inflammatory microglial activation during recovery.

Conclusions:
Since a humanized version of CR2fH, TT30, was shown to be safe, tolerated and nonimmunogenic in humans, targeted inhibition of alternative C pathway is a candidate therapy to promote recovery and potentiate response to rehab after stroke.
Abstract WMP5: Clinical and Cost Effectiveness of Rapid Recanalization within 6 Hours Performed by Intraarterial Thrombectomy for Acute Ischemic Stroke Patients
Authors: Jeong Hye Seon , Yu Hee Seon , Yoon Na Young , Lee Hae Mi , Shin Jong Wook , Kwon Hyon-Jo , Koh Hyeon-Song , Song Hee-Jung , Kim Jei
Published: June 2021

Introduction:
Rapid recanalization using intraarterial thrombectomy (IAT) is recommended to achieve rapid functional improvement and to shorten admission and rehabilitation period for acute ischemic stroke patients. We evaluated clinical and cost effectiveness of rapid recanalization within 6 hours by comparison with recanalization over 6 hours and no-recanalization of the occluded vessels in acute ischemic stroke patients.

Methods:
We analyzed clinical outcomes and medical costs of 230 acute ischemic stroke patients, who received IAT from October 2010 to May 2015. Patients were classified into rapid- (<6 hrs, n=143) and late- (> 6hrs, n=31) recanalization (≥2b or 3 of Thrombolysis in Cerebral Infarction grade [TICI]), and no-recanalization (TICI ≤2a, n=56) groups by the recanalization status after IAT. Differences of functional independence defined as 0-2 modified Rankin Score and medical costs checked at discharge and 1 year after IAT were compared between three groups. We also evaluated quality-adjusted life year (QALY) using EQ-5D 3 level version at 1 year after IAT and compared mortality and cost-effectiveness differences between the groups using QALY.

Results:
Functional independence was significantly higher in rapid-recanalization group than others at discharge (rapid-, 57%, vs. late-, 23% vs. no-recanalization, 0%,
p
<0.001) and after 1 year (70% vs. 40% vs. 6%,
p
<0.001). QALY (0.71±0.41 vs. 0.52±0.45 vs. 0.15±0.34,
p
<0.001) checked at 1 year was also higher in rapid-recanalization group than the others. Instead, one year mortality was lower in rapid-group than the others (10% vs. 17% vs. 43%,
p
<0.001). Medical cost of rapid-recanalization group was lower than other two groups at discharge ($9515 vs. $12711 vs. $12460,
p
<0.001) and after 1 year ($16753 vs. $21957 vs. $30718,
p
<0.001). On QALY adjusted cost-utility analysis, rapid-recanalization after IAT was more cost effective than late- ($27389/QALY) and no-recanalization ($51059/QALY) for acute ischemic stroke patients.

Conclusions:
The present data showed the importance of rapid recanalization within 6 hrs of acute ischemic stroke patients using IAT to reduce economic burden by the enhancement of functional outcomes during admission and after discharge.
Abstract WMP51: Risk and Timing of of Ischemic Stroke Following Acute Myocardial Infarction
Authors: Merkler Alexander E , Gialdini Gino , Murthy Santosh , Yaghi Shadi , Navi Babak , Iadecola Costantino , Weinsaft Jonathan W , Okin Peter M , Kamel Hooman
Published: June 2021

Background:
Acute myocardial infarction (MI) has long been reported as a risk factor for ischemic stroke, but the magnitude and duration of risk remains uncertain.

Methods:
We performed a crossover-cohort study using inpatient and outpatient claims data from a nationally representative 5% sample of Medicare beneficiaries from 2008 through 2014. We identified all patients ≥66 years of age with a first-recorded hospitalization for acute MI. The primary outcome was ischemic stroke. All predictors and outcomes were defined using previously validated
ICD-9-CM
codes. To exclude stroke that may have been due to percutaneous coronary intervention, we included only cases of ischemic stroke that occurred after discharge from the MI hospitalization. We compared the risk of ischemic stroke in successive 4-week periods during the 12 weeks after MI versus the corresponding 4-week periods 1 year later. To avoid immortal time bias, we limited our cohort to patients who remained alive and insured throughout the 15 month study period. Odds ratios (OR) and absolute risk differences were calculated using the Mantel-Haenszel estimator for matched data.

Results:
We identified 22,798 patients with an acute MI in whom the mean age was 77.4 (±7.9) years and 50.3% were women. In the 12 weeks after discharge, 216 patients (0.95%) developed a stroke, as compared to 21 (0.09%) patients in the corresponding 12-week period 1 year later. The absolute increase in stroke risk was 0.45% (95% confidence interval [CI], 0.36-0.55%) in the first 4 weeks after acute MI compared to the 4-week time period 1 year later, corresponding to an OR of 18.2 (95% CI, 8.1-50.6). The absolute risk increase was 0.24% (95% CI, 0.16-0.31%) during weeks 5-8 (OR, 8.7; 95% CI, 4.0-22.6) and 0.17% (95% CI, 0.10-0.23%) during weeks 9-12 (OR, 5.8; 95% CI, 2.7-14.1).

Conclusions:
Acute MI is associated with a substantially elevated short-term risk of ischemic stroke. This risk was independent of periprocedural stroke risk in the setting of coronary reperfusion therapies.
Abstract WMP52: Incidence of Ischemic and Hemorrhagic Stroke Amongst Asians in the United States
Authors: Moya Antonio , Gialdini Gino , Merkler Alexander , Kamel Hooman , Fink Matthew E , Navi Babak , Lerario Michael P , Bernadini Gary L , Chong Ji , Murthy Santosh B
Published: June 2021

Background:
Studies from Asia suggest that the overall proportion of hemorrhagic stroke is much higher compared to other parts of the world. We sought to evaluate the incidence of ischemic and hemorrhagic strokes in Asians living in the U.S. versus U.S. patients of other races and ethnicities.

Methods:
We identified all adult patients with acute ischemic or hemorrhagic stroke in the Nationwide Inpatient Sample from 2002-2011, using well-validated

International Classification of Diseases, 9
th
Revision, Clinical Modification

(
ICD-9-CM
) diagnosis codes. Our predictor variable was self-reported Asian race. Our primary outcome was the relative proportion of hemorrhagic compared to ischemic strokes. Survey weights were used to account for the sampling methodology. Trend analysis was then performed using the Chi square test for linear association.

Results:
We included 4,449,516 patients in the U.S. with stroke, of whom 3,794,438 (85.3%) had ischemic stroke and 655,078 (14.7%) had hemorrhagic stroke. Of these patients, 98,964 (2.2%) were Asian. Amongst the entire sample of stroke patients, Asians had a higher proportion of hemorrhagic strokes compared to the general population (24.0% vs. 14.5%, p<0.001). Asian patients were also more likely to have diabetes mellitus (28.8% vs. 23.7%, p<0.001) and hypertension (82.4% vs. 75.1%, p<0.001) compared to other races and ethnicities. Conversely, atrial fibrillation was less common in Asians (14.8% vs. 19%, p<0.001). There were no significant trends in the relative proportions of stroke types among different races and ethnicities over the past decade.

Conclusions:
The incidence of hemorrhagic strokes appears to be higher among Asian compared to patients of other races and ethnicities in the U.S. Further study is warranted to delineate the role of genetic versus environmental factors in explaining the greater propensity to hemorrhagic as opposed to ischemic stroke in Asians.
Abstract WMP69: Predictive Value of Diagnostic Testing for Detection of Deep Vein Thrombosis in Ischemic Stroke Patients with Intracardiac Shunt
Authors: Navalkele Digvijaya , Monlezun Dominique , Samai Alyana , El Khoury Ramy , Schluter Laurie , Freeman Melissa , Martin-Schild Sheryl
Published: June 2021

Background:
In the pursuit of stroke etiology, cardiac imaging with bubble study often reveals an intracardiac shunt. We sought to determine the yield of bilateral lower extremity ultrasound (BLE US) and magnetic resonance venography (MRV) of the pelvis in detection of deep vein thrombosis (DVT) as a source for paradoxical embolization in patients with ischemic stroke who have an intracardiac shunt.

Methods:
Patients admitted with AIS from 2008 through 2015 were included if the presence of intracardiac shunt was confirmed via echocardiography with bubble study. We examined the frequency of DVT (DVT+) among patients who had BLE US only, MRV pelvis only, or both BLE US and MRV. We then compared patients with evidence of DVT (DVT+) to those without evidence of DVT (DVT-).

Results:
Among 1,992 patients with AIS, 145 patients had confirmed evidence of an intracardiac shunt; of these, 40 patients (27.6%) had neither BLE US nor MRV studies, 29 patients (20.0%) had BLE US only, 4 patients (2.8%) had MRV only, and 72 patients (49.7%) had both BLE US and MRV. Among those with BLE US only, 2 patients (6.9%) were DVT+; of those who had MRV only, 2 patients (50.0%) were DVT+; of those who had both BLE US and MRV, 11 (15.3%) were DVT+. Overall, 14.3% of patients with an intracardiac shunt and work-up for DVT were found to have an occult DVT. No statistically significant differences were detected in demographic, baseline, in-hospital, or discharge characteristics when comparing DVT+ and DVT- patients.

Discussion:
The findings of this study support the use of BLE US and MRV to detect occult DVT among ischemic stroke patients with intracardiac shunt. In our sample population, 14.3% of patients were positive for occult DVT though no patient characteristics were associated with predicting the presence of DVT. This supports the need for adequate DVT screening in patients with AIS and positive bubble study.
Abstract WMP79: Characterization of Acute Stoke Induced by Photochemically-induced Thrombosis (PIT) in Nonhuman Primate (NHP)
Authors: Suzuki Junko , Itani Yoshitaka , Ogawa Shinya , Yamanaka Kazunori , Tanaka Yu , Takamatsu Hiroyuki
Published: June 2021

Introduction:
Tissue plasminogen activator (tPA) is the standard treatment for acute stroke but its widespread use is constrained by its narrow therapeutic window: better treatments are needed. Clinical stroke is heterogeneous in presentation and responsiveness to therapeutics. There are several methods of inducing acute cerebral ischemia in NHP and each model induces a differential pathology following occlusion. The goal of the current study was to characterize the PIT model of acute stroke in nonhuman primates.

Methods:
First, the time course of brain infarction between PIT and permanent middle cerebral artery (pMCA) occlusion was compared. PIT and pMCA occlusion were performed in cynomolgus macaques (n = 3/procedure). Total brain infarction volume and the volume of viable tissue surrounding the ischemic core that eventually becomes necrotic (“penumbra”) over time was measured using FLAIR MR imaging, 3, 6, 24 hours, 3, 5 and 7 days post-occlusion. In addition, functionality (Neurologic Deficit Score; NDS) was assessed 24 hours, 3, 5 and 7 days post-occlusion. Second, tPA’s (n = 7) therapeutic time window was determined. tPA (0.9 mg/kg) was i.v. infused 1, 3 and 4.5 hours post-occlusion. Control animals (n = 7) received a saline infusion 3 hours post-occlusion. Total brain infarction volume and presence of intracerebral hemorrhage 24 hours post-occlusion were measured. NDS was also determined.

Results:
First, significant brain infarction was observed 6 hours post-occlusion with FLAIR MR imaging in both models. Significant penumbral tissue was observed up to 6 hours post-occlusion. The brain infarction volume plateaued 5-7 days post-occlusion. In the second stage, tPA showed robust efficacy when it was infused 1 hour after occlusion. However, when tPA was infused either 3 or 4.5 hours post-occlusion, infarct volume and NDS were not different compared to saline treatment. Furthermore, significant intracranial hemorrhaging was observed when tPA was infused 3 or 4.5 hours post-occlusion.

Conclusion:
The current study suggests that the PIT model mimics human thrombotic stroke. In addition, since significant risks associated with tPA can also observed, the PIT model can be used to compare novel treatments with tPA in terms of intracranial hemorrhaging.
Abstract WMP80: Micro RNA-Therapy in Murine Thromboembolic Stroke
Authors: Vaibhav Kumar , Williams Shannon , Fatima Sumbul , Baban Babak , Dhandapani Krishnan M , Hess David , Hoda Md Nasrul
Published: June 2021

Background:
Micro RNAs (miRNAs) could target multiple mRNAs, repressing the protein translation. We report acute changes in humoral miRNAome in a murine thromboembolic stroke model (eMCAo), and demonstrate the benefits of miRNA therapy in improving cerebral blood flow (CBF).

Methods:
Non-biased micro RNA (miRNA) array and bioinformatics analysis was performed in plasma collected at 4h post-eMCAo from male mice (C57/B6, 16-weeks). Individual PCR for miRNAs was also performed in brain tissues at 24h post-eMCAo. Moreover, frozen human plasma samples collected at ~4.5h post-stroke were also used for miRNA analysis. Finally, the miRNA mimic that was predicted to target genes of our interest was also tested
in vivo
and
in vitro
.

Results:
Principal component analysis (PCA) of the miRNA-array showed ~68% variance in the humoral miRNAome 4h after eMCAo in mice, and a significant change in Stroke vs. Sham groups (Cut off value >2 fold; p<0.05). Of interest, the hairpin precursor of miR-449b was downregulated (~2.35 fold, p<0.05) at 4h post-eMCAo, while the mature miR-449b was also significantly reduced at 24h post-eMCAo. Mature miR-449b was significantly reduced in human stroke plasma, too. In human brain endothelial cells, miR-449b mimic downregulated gene expressions of both plasminogen activator inhibitor (PAI-1) and alpha 2- antiplasmin (α-AP) only in hypoxia but not during normoxia. Therefore, we finally tested the cholesterol-conjugated miR-449b mimic in the murine eMCAo model. Pre-treatment with miR-449b mimic (8 mg/kg bwt) increased the absolute CBF and reduced edema (as determined by MRI), and also improved the neurological outcomes and reduced % infarct volume (p<0.05).

Results:
The miR-449b mimic could be a possible therapy to suppress aberrant gene expressions of PAI-1 and α-AP, which will allow more spontaneous reperfusion and benefits from low dose tPA.