The Influence of Climatic Factors on the Provocation of Epileptic Seizures.

Background/Objectives: Recent studies provide the first indications of the impact of climate factors on human health, especially with individuals already grappling with internal and neurological conditions being particularly vulnerable. In the face of escalating climate change, our research delves into the specific influence of a spectrum of climatic factors and seasonal variations on the hospital admissions of patients receiving treatment for epileptic seizures at our clinic in Kaiserslautern. Methods: Our study encompassed data from 9366 epilepsy patients who were admitted to hospital due to epileptic seizures. We considered seven climate parameters that Germany's National Meteorological Service made available. We employed the Kruskal-Wallis test to examine the correlation between the frequency of admittance to our hospital in the mentioned patient group and seasons. Furthermore, we used conditional Poisson regression and distributed lag linear models (DLMs) to scrutinize the coherence of the frequency of patient admittance and the investigated climate parameters. The mentioned parameters were also analyzed in a subgroup analysis regarding the gender and age of patients and the classification of seizures according to ILAE 2017. Results: Our results demonstrate that climatic factors, such as precipitation and air pressure, can increase the frequency of hospital admissions for seizures in patients with general-onset epilepsy. In contrast, patients with focal seizures are less prone to climatic changes. Consequently, admittance to the hospital for seizures is less affected by climatic factors in the latter patient group. Conclusions: The present study demonstrated that climatic factors are possible trigger factors for the provocation of seizures, particularly in patients with generalized seizures. This was determined indirectly by analyzing the frequency of seizure-related emergency admissions and their relation to prevailing climate factors. Our study is consistent with other studies showing that climate factors, such as cerebral infarcts or cerebral hemorrhages, influence patients' health.

Influence of Time to Achieve Target Systolic Blood Pressure on Outcome After Intracerebral Hemorrhage: The Blood Pressure in Acute Stroke Collaboration.

OBJECTIVE: To investigate whether an earlier time to achieving and maintaining systolic blood pressure (SBP) at 120 to 140 mm Hg is associated with favorable outcomes in a cohort of patients with acute intracerebral hemorrhage. METHODS: We pooled individual patient data from randomized controlled trials registered in the Blood Pressure in Acute Stroke Collaboration. Time was defined as time form symptom onset plus the time (hour) to first achieve and subsequently maintain SBP at 120 to 140 mm Hg over 24 hours. The primary outcome was functional status measured by the modified Rankin Scale at 90 to 180 days. A generalized linear mixed models was used, with adjustment for covariables and trial as a random effect. RESULTS: A total of 5761 patients (mean age, 64.0 [SD, 13.0], 2120 [36.8%] females) were included in analyses. Earlier SBP control was associated with better functional outcomes (modified Rankin Scale score, 3-6; odds ratio, 0.98 [95% CI, 0.97-0.99]) and a significant lower risk of hematoma expansion (0.98, 0.96-1.00). This association was stronger in patients with bigger baseline hematoma volume (>10 mL) compared with those with baseline hematoma volume ≤10 mL (0.006 for interaction). Earlier SBP control was not associated with cardiac or renal adverse events. CONCLUSIONS: Our study confirms a clear time relation between early versus later SBP control (120-140 mm Hg) and outcomes in the one-third of patients with intracerebral hemorrhage who attained sustained SBP levels within this range. These data provide further support for the value of early recognition, rapid transport, and prompt initiation of treatment of patients with intracerebral hemorrhage.

Association Between Body Mass Index and Functional Outcomes in Patients With Intracerebral Hemorrhage.

BACKGROUND AND OBJECTIVES: Evidence of the so-called "obesity paradox," which refers to the protective effect and survival benefit of obesity in patients with spontaneous intracerebral hemorrhage (ICH), remains controversial. This study aims to determine the association between body mass index (BMI) and functional outcomes in patients with ICH and whether it is modified by race/ethnicity. METHODS: Included individuals were derived from the Ethnic/Racial Variations of Intracerebral Hemorrhage study, which prospectively recruited 1,000 non-Hispanic White, 1,000 non-Hispanic Black, and 1,000 Hispanic patients with spontaneous ICH. Only patients with available BMI were included. The primary outcome was 90-day mortality. Secondary outcomes were mortality at discharge, modified Rankin Scale (mRS), Barthel Index, and self-reported health status measures at 90 days. Associations between BMI and ICH outcomes were assessed using univariable and multivariable logistic, ordinal, and linear regression models, as appropriate. Sensitivity analyses after excluding frail patients and by patient race/ethnicity were performed. RESULTS: A total of 2,841 patients with ICH were included. The median age was 60 years (interquartile range 51-73). Most patients were overweight (n = 943; 33.2%) or obese (n = 1,032; 36.3%). After adjusting for covariates, 90-day mortality was significantly lower among overweight and obese patients than their normal weight counterparts (adjusted odds ratio [aOR] = 0.71 [0.52-0.98] and aOR = 0.70 [0.50-0.97], respectively). Compared with patients with BMI <25 kg/m2, those with BMI ≥25 kg/m2 had better 90-day mRS (aOR = 0.80 [CI 0.67-0.95]), EuroQoL Group 5-Dimension (EQ-5D) (aß = 0.05 [0.01-0.08]), and EQ-5D VAS (aß = 3.80 [0.80-6.98]) scores. These differences persisted after excluding withdrawal of care patients. There was an inverse relationship between BMI and 90-day mortality (aOR = 0.97 [0.96-0.99]). Although non-Hispanic White patients had significantly higher 90-day mortality than non-Hispanic Black and Hispanic (26.6% vs 19.5% vs 18.0%, respectively; p < 0.001), no significant interactions were found between BMI and race/ethnicity. No significant interactions between BMI and age or sex for 90-day mortality were found, whereas for 90-day mRS, there was a significant interaction with age (pinteraction = 0.004). CONCLUSION: We demonstrated that a higher BMI is associated with decreased mortality, improved functional outcomes, and better self-reported health status at 90 days, thus supporting the paradoxical role of obesity in patients with ICH. The beneficial effect of high BMI does not seem to be modified by race/ethnicity or sex, whereas age may play a significant role in patient functional outcomes.

Deep Resequencing of the 1q22 Locus in Non-Lobar Intracerebral Hemorrhage.

OBJECTIVE: Genome-wide association studies have identified 1q22 as a susceptibility locus for cerebral small vessel diseases, including non-lobar intracerebral hemorrhage (ICH) and lacunar stroke. In the present study, we performed targeted high-depth sequencing of 1q22 in ICH cases and controls to further characterize this locus and prioritize potential causal mechanisms, which remain unknown. METHODS: A total of 95,000 base pairs spanning 1q22, including SEMA4A, SLC25A44, and PMF1/PMF1-BGLAP were sequenced in 1,055 spontaneous ICH cases (534 lobar and 521 non-lobar) and 1,078 controls. Firth regression and Rare Variant Influential Filtering Tool analysis were used to analyze common and rare variants, respectively. Chromatin interaction analyses were performed using Hi-C, chromatin immunoprecipitation followed by sequencing, and chromatin interaction analysis with paired-end tag databases. Multivariable Mendelian randomization assessed whether alterations in gene-specific expression relative to regionally co-expressed genes at 1q22 could be causally related to ICH risk. RESULTS: Common and rare variant analyses prioritized variants in SEMA4A 5'-UTR and PMF1 intronic regions, overlapping with active promoter and enhancer regions based on ENCODE annotation. Hi-C data analysis determined that 1q22 is spatially organized in a single chromatin loop, and that the genes therein belong to the same topologically associating domain. Chromatin immunoprecipitation followed by sequencing and chromatin interaction analysis with paired-end tag data analysis highlighted the presence of long-range interactions between the SEMA4A-promoter and PMF1-enhancer regions prioritized by association testing. Multivariable Mendelian randomization analyses demonstrated that PMF1 overexpression could be causally related to non-lobar ICH risk. INTERPRETATION: Altered promoter-enhancer interactions leading to PMF1 overexpression, potentially dysregulating polyamine catabolism, could explain demonstrated associations with non-lobar ICH risk at 1q22, offering a potential new target for prevention of ICH and cerebral small vessel disease. ANN NEUROL 2024;95:325-337.

Pathogen-driven nucleotide overload triggers mitochondria-centered cell death in phagocytes.

Staphylococcus aureus is a dangerous pathogen that evolved refined immuno-evasive strategies to antagonize host immune responses. This involves the biogenesis of death-effector deoxyribonucleosides, which kill infectious foci-penetrating macrophages. However, the exact mechanisms whereby staphylococcal death-effector deoxyribonucleosides and coupled imbalances of intracellular deoxyribonucleotide species provoke immune cell death remain elusive. Here, we report that S. aureus systematically promotes an overload of deoxyribonucleotides to trigger mitochondrial rupture in macrophages, a fatal event that induces assembly of the caspase-9-processing apoptosome and subsequent activation of the intrinsic pathway of apoptosis. Remarkably, genetic disruption of this cascade not only helps macrophages coping with death-effector deoxyribonucleoside-mediated cytotoxicity but also enhances their infiltration into abscesses thereby ameliorating pathogen control and infectious disease outcomes in laboratory animals. Combined with the discovery of protective alleles in human CASP9, these data highlight the role of mitochondria-centered apoptosis during S. aureus infection and suggest that gene polymorphisms may shape human susceptibility toward a predominant pathogen.

Ten-Year Review of Antihypertensive Prescribing Practices After Stroke and the Associated Disparities From the Florida Stroke Registry.

BACKGROUND: Guideline-based hypertension management is integral to the prevention of stroke. We examine trends in antihypertensive medications prescribed after stroke and assess how well a prescriber's blood pressure (BP) medication choice adheres to clinical practice guidelines (BP-guideline adherence). METHODS AND RESULTS: The FSR (Florida Stroke Registry) uses statewide data prospectively collected for all acute stroke admissions. Based on established guidelines, we defined optimal BP-guideline adherence using the following hierarchy of rules: (1) use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker as first-line antihypertensive among diabetics; (2) use of thiazide-type diuretics or calcium channel blockers among Black patients; (3) use of beta blockers among patients with compelling cardiac indication; (4) use of thiazide, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, or calcium channel blocker class as first line in all others; (5) beta blockers should be avoided as first line unless there is a compelling cardiac indication. A total of 372 254 cases from January 2010 to March 2020 are in the FSR with a diagnosis of acute ischemic stroke, hemorrhagic stroke, transient ischemic attack, or subarachnoid hemorrhage; 265 409 with complete data were included in the final analysis. Mean age was 70±14 years; 50% were women; and index stroke subtypes were 74% acute ischemic stroke, 11% intracerebral hemorrhage, 11% transient ischemic attack, and 4% subarachnoid hemorrhage. BP-guideline adherence to each specific rule ranged from 48% to 74%, which is below quality standards of 80%, and was lower among Black patients (odds ratio, 0.7 [95% CI, 0.7-0.83]; P<0.001) and those with atrial fibrillation (odds ratio, 0.53 [95% CI, 0.50-0.56]; P<0.001) and diabetes (odds ratio, 0.65 [95% CI, 0.61-0.68]; P<0.001). CONCLUSIONS: This large data set demonstrates consistently low rates of BP-guideline adherence over 10 years. There is an opportunity for monitoring hypertensive management after stroke.

The combined effect of lifestyle factors and polygenic scores on age at onset in Parkinson's disease.

Objective: To investigate the association between a Parkinson's disease (PD)-specific polygenic score (PGS) and protective lifestyle factors on age at onset (AAO) in PD. Methods: We included data from 4375 patients with idiopathic PD, 167 patients with GBA1-PD, and 3091 healthy controls of European ancestry from AMP-PD, PPMI, and Fox Insight cohorts. The PGS was calculated based on a previously proposed composition of 1805 variants. The association between PGS and lifestyle factors (i.e., coffee, tobacco, and aspirin) on AAO was assessed with linear and Cox proportional hazards models. Results: The PGS showed a negative association with AAO (ß=-1.07, p=6×10-7). The use of one, two, or three of the protective lifestyle factors showed a reduction in the hazard ratio by 21% (p=0.0001), 45% (p<2×10-16), and 55% (p<2×10-16), respectively, compared to no use. An additive effect of aspirin (ß=7.61, p=8×10-7) and PGS (ß=-1.63, p=0.0112) was found for AAO without an interaction (p=0.9789) in the linear regressions, and similar effects were seen for tobacco. Aspirin is shown to be a better predictor of AAO (R2=0.1740) compared to coffee and tobacco use (R2=0.0243, R2=0.0295) or the PGS (R2=0.0141). In contrast, no association between aspirin and AAO was found in GBA1-PD (p>0.05). Interpretation: In our cohort, coffee, tobacco, aspirin, and PGS are independent predictors of PD AAO. Additionally, lifestyle factors seem to have a greater influence on AAO than common genetic risk variants with aspirin presenting the largest effect. External validation of our findings is needed.

Interaction of Mitochondrial Polygenic Score and Lifestyle Factors in LRRK2 p.Gly2019Ser Parkinsonism.

BACKGROUND: A mitochondrial polygenic score (MGS) is composed of genes related to mitochondrial function and found to be associated with Parkinson's disease (PD) risk. OBJECTIVE: To investigate the impact of the MGS and lifestyle/environment on age at onset (AAO) in LRRK2 p.Gly2019Ser parkinsonism (LRRK2-PD) and idiopathic PD (iPD). METHODS: We included N = 486 patients with LRRK2-PD and N = 9259 with iPD from the Accelerating Medicines Partnership® Parkinson's Disease Knowledge Platform (AMP-PD), Fox Insight, and a Tunisian Arab-Berber founder population. Genotyping data were used to perform the MGS analysis. Additionally, lifestyle/environmental data were obtained from the PD Risk Factor Questionnaire (PD-RFQ). Linear regression models were used to assess the relationship between MGS, lifestyle/environment, and AAO. RESULTS: Our derived MGS was significantly higher in PD cases compared with controls (P = 1.1 × 10-8 ). We observed that higher MGS was significantly associated with earlier AAO in LRRK2-PD (P = 0.047, ß = -1.40) and there was the same trend with a smaller effect size in iPD (P = 0.231, ß = 0.22). There was a correlation between MGS and AAO in LRRK2-PD patients of European descent (P = 0.049, r = -0.12) that was visibly less pronounced in Tunisians (P = 0.449, r = -0.05). We found that the MGS interacted with caffeinated soda consumption (P = 0.003, ß = -5.65) in LRRK2-PD and with tobacco use (P = 0.010, ß = 1.32) in iPD. Thus, patients with a high MGS had an earlier AAO only if they consumed caffeinated soda or were non-smokers. CONCLUSIONS: The MGS was more strongly associated with earlier AAO in LRRK2-PD compared with iPD. Caffeinated soda consumption or tobacco use interacted with MGS to predict AAO. Our study suggests gene-environment interactions as modifiers of AAO in LRRK2-PD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Clinical utility of polygenic risk scores: a critical 2023 appraisal.

Since their first appearance in the context of schizophrenia and bipolar disorder in 2009, polygenic risk scores (PRSs) have been described for a large number of common complex diseases. However, the clinical utility of PRSs in disease risk assessment or therapeutic decision making is likely limited because PRSs usually only account for the heritable component of a trait and ignore the etiological role of environment and lifestyle. We surveyed the current state of PRSs for various diseases, including breast cancer, diabetes, prostate cancer, coronary artery disease, and Parkinson disease, with an extra focus upon the potential improvement of clinical scores by their combination with PRSs. We observed that the diagnostic and prognostic performance of PRSs alone is consistently low, as expected. Moreover, combining a PRS with a clinical score at best led to moderate improvement of the power of either risk marker. Despite the large number of PRSs reported in the scientific literature, prospective studies of their clinical utility, particularly of the PRS-associated improvement of standard screening or therapeutic procedures, are still rare. In conclusion, the benefit to individual patients or the health care system in general of PRS-based extensions of existing diagnostic or treatment regimens is still difficult to judge.

Deep resequencing of the 1q22 locus in non-lobar intracerebral hemorrhage.

Objective: Genome-wide association studies have identified 1q22 as a susceptibility locus for cerebral small vessel diseases (CSVDs), including non-lobar intracerebral hemorrhage (ICH) and lacunar stroke. In the present study we performed targeted high-depth sequencing of 1q22 in ICH cases and controls to further characterize this locus and prioritize potential causal mechanisms, which remain unknown. Methods: 95,000 base pairs spanning 1q22 , including SEMA4A, SLC25A44 and PMF1 / PMF1-BGLAP were sequenced in 1,055 spontaneous ICH cases (534 lobar and 521 non-lobar) and 1,078 controls. Firth regression and RIFT analysis were used to analyze common and rare variants, respectively. Chromatin interaction analyses were performed using Hi-C, ChIP-Seq and ChIA-PET databases. Multivariable Mendelian randomization (MVMR) assessed whether alterations in gene-specific expression relative to regionally co-expressed genes at 1q22 could be causally related to ICH risk. Results: Common and rare variant analyses prioritized variants in SEMA4A 5'-UTR and PMF1 intronic regions, overlapping with active promoter and enhancer regions based on ENCODE annotation. Hi-C data analysis determined that 1q22 is spatially organized in a single chromatin loop and that the genes therein belong to the same Topologically Associating Domain. ChIP-Seq and ChIA-PET data analysis highlighted the presence of long-range interactions between the SEMA4A -promoter and PMF1 -enhancer regions prioritized by association testing. MVMR analyses demonstrated that PMF1 overexpression could be causally related to non-lobar ICH risk. Interpretation: Altered promoter-enhancer interactions leading to PMF1 overexpression, potentially dysregulating polyamine catabolism, could explain demonstrated associations with non-lobar ICH risk at 1q22 , offering a potential new target for prevention of ICH and CSVD.

Impact of Time to Treatment on Endovascular Thrombectomy Outcomes in the Early Versus Late Treatment Time Windows.

BACKGROUND: The impact of time to treatment on outcomes of endovascular thrombectomy (EVT) especially in patients presenting after 6 hours from symptom onset is not well characterized. We studied the differences in characteristics and treatment timelines of EVT-treated patients participating in the Florida Stroke Registry and aimed to characterize the extent to which time impacts EVT outcomes in the early and late time windows. METHODS: Prospectively collected data from Get With the Guidelines-Stroke hospitals participating in the Florida Stroke Registry from January 2010 to April 2020 were reviewed. Participants were EVT patients with onset-to-puncture time (OTP) of ≤24 hours and categorized into early window treated (OTP ≤6 hours) and late window treated (OTP >6 and ≤24 hours). Association between OTP and favorable discharge outcomes (independent ambulation, discharge home and to acute rehabilitation facility) as well as symptomatic intracerebral hemorrhage and in-hospital mortality were examined using multilevel-multivariable analysis with generalized estimating equations. RESULTS: Among 8002 EVT patients (50.9% women; median age [±SD], 71.5 [±14.5] years; 61.7% White, 17.5% Black, and 21% Hispanic), 34.2% were treated in the late time window. Among all EVT patients, 32.4% were discharged home, 23.5% to rehabilitation facility, 33.7% ambulated independently at discharge, 5.1% had symptomatic intracerebral hemorrhage, and 9.2% died. As compared with the early window, treatment in the late window was associated with lower odds of independent ambulation (odds ratio [OR], 0.78 [0.67-0.90]) and discharge home (OR, 0.71 [0.63-0.80]). For every 60-minute increase in OTP, the odds of independent ambulation reduced by 8% (OR, 0.92 [0.87-0.97]; P<0.001) and 1% (OR, 0.99 [0.97-1.02]; P=0.5) and the odds of discharged home reduced by 10% (OR, 0.90 [0.87-0.93]; P<0.001) and 2% (OR, 0.98 [0.97-1.00]; P=0.11) in the early and late windows, respectively. CONCLUSIONS: In routine practice, just over one-third of EVT-treated patients independently ambulate at discharge and only half are discharged to home/rehabilitation facility. Increased time from symptom onset to treatment is significantly associated with lower chance of independent ambulation and ability to be discharged home after EVT in the early time window.

A 10-year review of antihypertensive prescribing practices after stroke and the associated disparities from the Florida Stroke Registry.

Background: Guideline based hypertension management is integral to the prevention of stroke. We examine trends in antihypertensive medications prescribed after stroke and assess how well a prescribers' blood pressure medication choice adheres to clinical practice guidelines (Prescribers'-Choice Adherence). Methods: The Florida Stroke registry (FSR) utilizes statewide data prospectively collected for all acute stroke admissions. Based on established guidelines we defined optimal Prescribers'-Choice Adherence using the following hierarchy of rules: 1) use of an angiotensin inhibitor (ACEI) or angiotensin receptor blocker (ARB) as first-line antihypertensive among diabetics; 2) use of thiazide-type diuretics or calcium channel blockers (CCB) among African-American patients; 3) use of beta-adrenergic blockers (BB) among patients with compelling cardiac indication (CCI) 4) use of thiazide, ACEI/ARB or CCB class as first-line in all others; 5) BB should be avoided as first line unless CCI. RESULTS: A total of 372,254 cases from January 2010 to March 2020 are in FSR with a diagnosis of acute ischemic, hemorrhagic stroke, transient ischemic attack or subarachnoid hemorrhage; 265,409 with complete data were included in the final analysis. Mean age 70 +/-14 years, 50% female, index stroke subtype of 74% acute ischemic stroke and 11% intracerebral hemorrhage. Prescribers'-Choice Adherence to each specific rule ranged from 48-74% which is below quality standards of 85%. There were race-ethnic disparities with only 49% Prescribers choice Adherence for African Americans patients. Conclusion: This large dataset demonstrates consistently low rates of Prescribers'-Choice Adherence over 10 years. There is an opportunity for quality improvement in hypertensive management after stroke.

Red Cell Microparticles Suppress Hematoma Growth Following Intracerebral Hemorrhage in Chronic Nicotine-Exposed Rats.

Spontaneous intracerebral hemorrhage (sICH) is a disabling stroke sub-type, and tobacco use is a prominent risk factor for sICH. We showed that chronic nicotine exposure enhances bleeding post-sICH. Reduction of hematoma growth is a promising effective therapy for sICH in smoking subjects. Red-blood-cell-derived microparticles (RMPs) are hemostatic agents that limit hematoma expansion following sICH in naïve rats. Considering the importance of testing the efficacy of experimental drugs in animal models with a risk factor for a disease, we tested RMP efficacy and the therapeutic time window in limiting hematoma growth post-sICH in rats exposed to nicotine. Young rats were chronically treated with nicotine using osmotic pumps. sICH was induced in rats using an injection of collagenase in the right striatum. Vehicle/RMPs were administered intravenously. Hematoma volume and neurological impairment were quantified ≈24 h after sICH. Hematoma volumes in male and female nicotine-exposed rats that were treated with RMPs at 2 h post-sICH were significantly lower by 26 and 31% when compared to their respective control groups. RMP therapy was able to limit hematoma volume when administered up to 4.5 h post-sICH in animals of both sexes. Therefore, RMPs may limit hematoma growth in sICH patients exposed to tobacco use.

Direct Bypass Surgery for Moyamoya and Steno-occlusive Vasculopathy: Clinical Outcomes, Intraoperative Blood Flow Analysis, Long-term Follow-up, and Long-term Bypass Patency in a Single Surgeon Case Series of 162 Procedures.

BACKGROUND: Cerebral extracranial-intracranial (EC-IC) direct bypass is a commonly used procedure for the treatment of cerebral hypoperfusion secondary to chronic steno-occlusive vasculopathy. We sought to determine clinical outcomes, intraoperative blood flow analysis, long term follow up, and long term patency rates from a single surgeon's series of direct cerebral bypass for moyamoya disease, moyamoya syndrome, and steno-occlusive disease. METHODS: We reviewed clinical, demographic, operative and neuroimaging records for all patients who underwent a direct EC-IC bypass by the senior author between August 1999 and November 2020. Primary outcomes analyzed were functional long-term outcomes (by modified Rankin score [mRS]), surgical complications, and short-term and long-term bypass patency. RESULTS: A total of 162 revascularization procedures in 124 patients were performed. Mean clinical follow up time was 2 years 11 months. The combined immediate and long term postoperative stroke and/or intracerebral hemorrhage rate was 6.2%. There were 17 bypasses (10%) that were found to be occluded at long-term follow-up, all but one were asymptomatic. Long-term graft occlusion was correlated with presence of complete collateralization on preoperative angiography but not cut flow index (CFI). Overall, patients had a significant clinical improvement with a mean mRS score 1.8 preoperatively and 1.2 postoperatively. CONCLUSIONS: In our consecutive series of patients treated with direct EC-IC cerebral bypass, there was significant improvement in functional outcome as measured by the mRS. The long term patency rate was 90%. There was a statistically significant correlation between complete or incomplete angiographic collateralization patterns and long-term bypass occlusion. There was no correlation between bypass type, clinical syndrome, or CFI and long-term occlusions. The role of bypass surgery and the need for surgical expertise remain strong in the treatment of moyamoya variants and a select group of atherosclerotic steno-occlusive patients.

Red Blood Cell Microparticles Limit Hematoma Growth in Intracerebral Hemorrhage.

BACKGROUND: Spontaneous intracerebral hemorrhage (sICH) is the deadliest stroke subtype with no effective therapies. Limiting hematoma expansion is a promising therapeutic approach. Red blood cell-derived microparticles (RMPs) are novel hemostatic agents. Therefore, we studied the potential of RMPs in limiting hematoma growth and improving outcomes post-sICH. METHODS: sICH was induced in rats by intrastriatal injection of collagenase. RMPs were prepared from human RBCs by high-pressure extrusion. Behavioral and hematoma/lesion volume assessment were done post-sICH. The optimal dose, dosing regimen, and therapeutic time window of RMP therapy required to limit hematoma growth post-sICH were determined. We also evaluated the effect of RMPs on long-term behavioral and histopathologic outcomes post-sICH. RESULTS: RMP treatment limited hematoma growth following sICH. Hematoma volume (mm3) for vehicle- and RMP- (2.66×1010 particles/kg) treated group was 143±8 and 86±4, respectively. The optimal RMP dosing regimen that limits hematoma expansion was identified. RMPs limit hematoma volume when administered up to 4.5-hour post-sICH. Hematoma volume in the 4.5-hour post-sICH RMP treatment group was lower by 24% when compared with the control group. RMP treatment also improved long-term histopathologic and behavioral outcomes post-sICH. CONCLUSIONS: Our results demonstrate that RMP therapy limits hematoma growth and improves outcomes post-sICH in a rodent model. Therefore, RMPs have the potential to limit hematoma growth in sICH patients.

Efficacy of mechanisms of neuroplasticity after a stroke.

BACKGROUND: The sequelae of stoke, including the loss and recovery of function, are strongly linked to the mechanisms of neuroplasticity. Rehabilitation and non-invasive brain stimulation (NIBS) paradigms have shown promise in modulating corticomotor neuroplasticity to promote functional recovery in individuals post-stroke. However, an important limitation to these approaches is that while stroke recovery depends on the mechanisms of neuroplasticity, those mechanisms may themselves be altered by a stroke. OBJECTIVE: Compare Transcranial Magnetic Stimulation (TMS)-based assessments of efficacy of mechanism of neuroplasticity between individuals post-stroke and age-matched controls. METHODS: Thirty-two participants (16 post-stroke, 16 control) underwent an assessment of mechanisms of neuroplasticity, measured by the change in amplitude of motor evoked potentials elicited by single-pulse TMS 10-20 minutes following intermittent theta-burst stimulation (iTBS), and dual-task effect (DTE) reflecting cognitive-motor interference (CMI). In stroke participants, we further collected: time since stroke, stroke type, location, and Stroke Impact Scale 16 (SIS-16). RESULTS: Although there was no between-group difference in the efficacy of TMS-iTBS neuroplasticity mechanism (p = 0.61, η2 = 0.01), the stroke group did not exhibit the expected facilitation to TMS-iTBS (p = 0.60, η2 = 0.04) that was shown in the control group (p = 0.016, η2 = 0.18). Sub-cohort analysis showed a trend toward a difference between those in the late-stage post-stroke and the control group (p = 0.07, η2 = 0.12). Within the post-stroke group, we found significant relationships between TMS-iTBS neuroplasticity and time since stroke onset, physical function (SIS-16), and CMI (all rs > |0.53| and p-values < 0.05). CONCLUSIONS: In this proof-of-principle study, our findings suggested altered mechanisms of neuroplasticity in post-stroke patients which were dependent on time since stroke and related to motor function. TMS-iTBS neuroplasticity assessment and its relationship with clinical functional measures suggest that TMS may be a useful tool to study post-stroke recovery. Due to insufficient statistical power and high variability of the data, generalization of the findings will require replication of the results in a larger, better-characterized cohort.

Comparing Protection of Remote Limb with Resveratrol Preconditioning following Rodent Subarachnoid Hemorrhage.

BACKGROUND: Preventing delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) remains an important therapeutic target. Preconditioning stimulates multiple endogenous protective mechanisms and may be a suitable treatment for DCI following SAH. We here compare remote limb conditioning with resveratrol conditioning in a clinically relevant SAH model. METHODS: We produced a SAH in 39 male Sprague Dawley rats using a single injection model. Animals were randomized to four groups: repetitive limb conditioning with a blood pressure cuff, sham conditioning, intraperitoneal resveratrol (10 mg/kg) or intraperitoneal vehicle administered at 24, 48 and 72 h after SAH. On day 4 neurological and behavioral scores were obtained, and animals were euthanized. The cross-sectional area of the basilar artery was measured at the vertebrobasilar junction, and at the mid and distal segments. Hippocampal cells were counted in both hemispheres and normalized per mm length. We compared true limb preconditioning with sham conditioning and resveratrol with vehicle preconditioning. RESULTS: The cross-sectional area of the mid-basilar artery in the true limb preconditioning group was significantly larger by 43% (p = 0.03) when compared with the sham preconditioning group. No differences in the cross-sectional area were found in the resveratrol-treated group when compared to the vehicle-treated group. We found no differences in the neuro score, behavioral score, and in mean hippocampal neuron counts between the groups. CONCLUSION: We found beneficial vascular effects of remote limb preconditioning on SAH-induced basilar artery vasoconstriction. Our findings support further studies of limb preconditioning as a potential treatment after SAH.

Risk Factors Associated With Mortality and Neurologic Disability After Intracerebral Hemorrhage in a Racially and Ethnically Diverse Cohort.

Introduction: Intracerebral hemorrhage (ICH) is the most severe subtype of stroke. Its mortality rate is high, and most survivors experience significant disability. Objective: To assess primary patient risk factors associated with mortality and neurologic disability 3 months after ICH in a large, racially and ethnically balanced cohort. Design, Setting, and Participants: This cohort study included participants from the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study, which prospectively recruited 1000 non-Hispanic White, 1000 non-Hispanic Black, and 1000 Hispanic patients with spontaneous ICH to study the epidemiological characteristics and genomics associated with ICH. Participants included those with uniform data collection and phenotype definitions, centralized neuroimaging review, and telephone follow-up at 3 months. Analyses were completed in November 2021. Exposures: Patient demographic and clinical characteristics as well as hospital event and imaging variables were examined, with characteristics meeting P < .20 considered candidates for a multivariate model. Elements included in the ICH score were specifically analyzed. Main Outcomes and Measures: Individual characteristics were screened for association with 3-month outcome of neurologic disability or mortality, as assessed by a modified Rankin Scale (mRS) score of 4 or greater vs 3 or less under a logistic regression model. A total of 25 characteristics were tested in the final model, which minimized the Akaike information criterion. Analyses were repeated removing individuals who had withdrawal of care. Results: A total of 2568 patients (mean [SD] age, 62.4 [14.7] years; 1069 [41.6%] women and 1499 [58.4%] men) had a 3-month outcome determination available, including death. The final logistic model had a significantly higher area under the receiver operating characteristics curve (C = 0.88) compared with ICH score alone (C = 0.76; P < .001). Among characteristics associated with neurologic disability and mortality were larger log ICH volume (OR, 2.74; 95% CI, 2.36-3.19; P < .001), older age (OR per 1-year increase, 1.04; 95% CI, 1.02-1.05; P < .001), pre-ICH mRS score (OR, 1.62; 95% CI, 1.41-1.87; P < .001), lobar location (OR, 0.22; 95% CI, 0.16-0.30; P < .001), and presence of infection (OR, 1.85; 95% CI, 1.42-2.41; P < .001). Conclusions and Relevance: The findings of this cohort study validate ICH score elements and suggest additional baseline and interim patient characteristics were associated with variation in 3-month outcome.