Fe-implanted ZnO: Magnetic precipitates versus dilution

Nowadays ferromagnetism is often found in potential diluted magnetic semiconductor systems. However, many authors argue that the observed ferromagnetism stems from ferromagnetic precipitates or spinodal decomposition rather than from carrier mediated magnetic impurities, as required for a diluted magnetic semiconductor. In the present paper we answer this question for Fe-implanted ZnO single crystals comprehensively. Different implantation fluences and temperatures and post-implantation annealing temperatures have been chosen in order to evaluate the structural and magnetic properties over a wide range of parameters. Three different regimes with respect to the Fe concentration and the process temperature are found: 1) Disperse Fe$^{2+}$ and Fe$^{3+}$ at low Fe concentrations and low processing temperatures, 2) FeZn$_2$O$_4$ at very high processing temperatures and 3) an intermediate regime with a co-existence of metallic Fe (Fe$^0$) and ionic Fe (Fe$^{2+}$ and Fe$^{3+}$). Ferromagnetism is only observed in the latter two cases, where inverted ZnFe$_2$O$_4$ and $\alpha$-Fe nanocrystals are the origin of the observed ferromagnetic behavior, respectively. The ionic Fe in the last case could contribute to a carrier mediated coupling. However, their separation is too large to couple ferromagnetically due to the lack of p-type carrier. For comparison investigations of Fe-implanted epitaxial ZnO thin films are presented.Comment: 14 pages, 17 figure

Prognostic significance of third ventricle blood volume in intracerebral haemorrhage with severe ventricular involvement

Background and purpose: Intraventricular haemorrhage (IVH) is an independent predictor of poor outcome in spontaneous intracerebral haemorrhage (ICH). Larger IVH volume and increasing number of affected ventricles have been associated with worse prognosis, however, little is known about the prognostic value of blood volume in the different parts of the ventricular system. Therefore, the correlation of IVH volume in the third, fourth and lateral ventricles with outcome in patients with ICH and severe IVH, treated with intraventricular fibrinolysis (IVF), was investigated. Methods: Patients with ICH <40 ml, severe IVH and acute hydrocephalus were treated with IVF. The course of IVH volume for each ventricle was measured by CT based volumetry. Outcome at 90 days was assessed by a telephone follow-up survey and correlated with initial IVH volume. Results: 50 patients aged 62.5±10.3 years with spontaneous ICH (12.5±10.8 ml) and severe IVH (33.5±25 ml) were included. Clearance of the third and fourth ventricle from blood occurred after 3±1.9 days. Initial IVH volume in the third ventricle (3.8±3.3 ml) was predictive for poor outcome (OR 2.6 per ml, p=0.02). Correlation between larger IVH volume in the fourth ventricle and poor outcome showed a trend towards significance (p=0.07). Total IVH volume and lateral ventricle IVH volume were not correlated with outcome. Conclusion: Despite rapid clot removal, initial IVH volume in the third ventricle was a strong and independent negative predictor. This is possibly explained by irreversible damage of brainstem structures by the initial mass effect of IVH

Influence of bundled care treatment on functional outcome in patients with intracerebral hemorrhage

Background and aimsGeneral guideline recommendations in patients with intracerebral hemorrhage (ICH) include blood pressure-, temperature- and glucose management. The therapeutic effect of such a “care bundle” (blood pressure lowering, glycemic control, and treatment of pyrexia) on clinical outcomes becomes increasingly established. For the present study, we aimed to investigate associations of strict bundled care treatment (BCT) with clinical outcomes and characterize associations with key outcome effectors such as hematoma enlargement (HE) and peak perihemorrhagic edema (PHE).MethodsWe screened consecutive ICH patients (n = 1,322) from the prospective UKER-ICH cohort study. BCT was defined as achieving and maintaining therapeutic ranges for systolic blood pressure (110–160 mmHg), glucose (80–180 mg/dL), and body temperature (35.5–37.5°C) over the first 72 h. The primary outcome was the functional outcome at 12 months (modified Rankin Scale (mRS) 0–3). Secondary outcomes included mortality at 12 months, the occurrence of hematoma enlargement, and the development of peak perihemorrhagic edema. Confounding was addressed by a doubly robust methodology to calculate the absolute treatment effect (ATE) and by calculating e-values.ResultsA total of 681 patients remained for analysis, and 182 patients fulfilled all three BCT criteria and were compared to 499 controls. The ATE of BCT to achieve the primary outcome was 9.3%, 95% CI (1.7 to 16.9), p &lt; 0.001; e-value: 3.1, CI (1.8). Mortality at 12 months was significantly reduced by BCT [ATE: −12.8%, 95% CI (−19.8 to −5.7), p &lt; 0.001; e-value: 3.8, CI (2.2)], and no association was observed for HE or peak PHE. Significant drivers of BCT effect on the primary outcome were systolic blood pressure control (ATE: 15.9%) and maintenance of normothermia (ATE: 10.9%).ConclusionStrict adherence to this “care bundle” over the first 72 h during acute hospital care in patients with ICH was independently associated with improved functional long-term outcome, driven by systolic blood pressure control and maintenance of normothermia. Our findings strongly warrant prospective validation to determine the generalizability especially in Western countries.Clinical trial registration:ClinicalTrials.gov, identifier [ID: NCT03183167]

Quantitative Corticospinal Tract Assessment in Acute Intracerebral Hemorrhage

Abstract Intracerebral hemorrhage (ICH) prognostication during the acute phase is often subjective among physicians and often affects treatment decisions. The present study explores objective imaging parameters using quantitative corticospinal tract (CST) fiber reconstruction during the acute phase of ICH and correlates these parameters with functional outcome and patient recovery. We prospectively enrolled nonsurgical spontaneous supratentorial ICH patients and obtained an MRI scan on day 5 ± 1. Q-space diffeomorphic reconstruction was performed using DSI Studio, and quantitative anisotropy (QA) was calculated. The CST was reconstructed based on QA. The dichotomized modified Rankin Scale score on day 90 (favorable outcome = 0–2) and Barthel Index (favorable recovery = 100 on day 90 or improvement between discharge and day 90 > 60%) were assessed. Thirty-three patients, median age 72 years (interquartile range (IQR) 64–83), 21 female (64%), 21 (64%) with lobar hemorrhage, median ICH volume on admission 15.0 (IQR 7.0–27.4) mL, were included. Sixteen patients (48%) had a favorable outcome and 24 (73%) had a favorable recovery. The mean number of ipsilesional reconstructed CST fiber pathways was higher in patients with favorable outcomes (153 (standard deviation (SD) 103) vs. 60 (SD 39), p = 0.003) and predicted outcome after adjustment (Exp(B) = 1.016 (95% CI = 1.002–1.030)). QA in the ipsilesional posterior limb of the internal capsule showed a trend towards an association with favorable outcome (Exp(B) = 1.194 (95% CI = 0.991–1.439 (adjusted))). The total (ipsilesional + contralesional) number of reconstructed fiber pathways was associated with favorable recovery (Exp(B) = 1.025 (95% CI = 1.003–1.047 (adjusted))). Quantitative tractography parameters assessed in the acute phase of ICH may represent a promising predictor of long-term outcome and recovery. This might facilitate prognostic evaluation and organization of rehabilitation

Peak Edema Extension Distance: An Edema Measure Independent from Hematoma Volume Associated with Functional Outcome in Intracerebral Hemorrhage

BackgroundOur objective was to test the association between hematoma volume and long-term (> 72 h) edema extension distance (EED) evolution and the association between peak EED and early EED increase with functional outcome at 3 months in patients with intracerebral hemorrhage (ICH).MethodsThis retrospective cohort study included patients with spontaneous supratentorial ICH between January 2006 and January 2014. EED, an edema measure defined as the distance between the hematoma border and the outer edema border, was calculated by using absolute hematoma and edema volumes. We used multivariable logistic regression accounting for age, ICH volume, and location and receiver operating characteristic analysis for assessing measures associated with functional outcome and EED evolution. Functional outcome after 3 months was assessed by using the modified Rankin Scale (0–3 = favorable, 4–6 = unfavorable). To identify properties associated with peak EED multivariable linear and logistic regression analyses were conducted.ResultsA total of 292 patients were included. Median age was 70 years (interquartile range [IQR] 62–78), median ICH volume on admission 17.7 mL (IQR 7.9–40.2), median peak perihemorrhagic edema (PHE) volume was 37.5 mL (IQR 19.1–60.6), median peak EED was 0.67 cm (IQR 0.51–0.84) with an early EED increase up to 72 h (EED72–0) of 0.06 cm (− 0.02 to 0.15). Peak EED was found to be independent of ICH volume (R2 = 0.001, p = 0.6). In multivariable analyses, peak EED (odds ratio 0.224, 95% confidence interval [CI] [0.071–0.705]) and peak PHE volume (odds ratio 0.984 [95% CI 0.973–0.994]) were inversely associated with favorable functional outcome at 3 months. Receiver operating characteristic analysis identified a peak PHE volume of 26.8 mL (area under the curve 0.695 [95% CI 0.632–0.759]; p ≤ 0.001) and a peak EED of 0.58 cm (area under the curve 0.608 [95% CI 0.540–0.676]; p = 0.002) as best predictive values for outcome discrimination.ConclusionsCompared with absolute peak PHE volume, peak EED represents a promising edema measure in patients with ICH that is largely hematoma volume-independent and nevertheless associated with functional outcome.Open Access funding enabled and organized by Projekt DEAL.Friedrich-Alexander-Universität Erlangen-Nürnberg (1041

Influence of Early Enteral Nutrition on Clinical Outcomes in Neurocritical Care Patients With Intracerebral Hemorrhage

Objective: Early enteral nutrition (EEN) represents the current standard of care for patients treated in general intensive care units (ICU). Specific nutritional recommendations for patients receiving dedicated neurocritical care are not established. This study investigated associations of EEN with clinical outcomes for patients suffering from intracerebral hemorrhage treated at a neurological ICU (NICU). Methods: This retrospective cohort study included patients admitted to the NICU with atraumatic ICH over a 4-year period. Nutritional data, demographic, clinical, radiological, and laboratory characteristics were assessed. EEN was defined as any enteral nutrition within 48 hours after admission. Comparisons were undertaken for patients with EEN vs. those without, further propensity score (PS) matching (caliper 0.2; one: many) was used to account for baseline imbalances. Primary outcome was the modified Rankin Scale (0–3 = favorable, 4–6 = unfavorable) at 12 months, secondary outcomes comprised perihemorrhagic edema (PHE) volume, infectious complications during the hospital stay, and mRS at 3 months, as well as mortality rates at 3 and 12 months. Results: Of 166 ICH-patients treated at the NICU, 51 (30.7%) patients received EEN, and 115 (69.3%) patients received no EEN (nEEN). After propensity score matching, calories delivered from enteral nutrition (EEN 161.4 [106.4–192.3] kcal/day vs. nEEN 0.0 [0.0–0.0], P < 0.001) and the total calories (EEN 190.0 [126.0–357.0] kcal/day vs. nEEN 33.6 [0.0–190.0] kcal/day, P < 0.001) were significantly different during the first 48 h admitted in NICU. Functional outcome at 12 months (mRS 4–6, EEN 33/43 [76.7%] vs. nEEN, 49/64 [76. 6%]; P = 1.00) was similar in the two groups. There were neither differences in mRS at 3 months, nor in mortality rates at 3 and 12 months between the two groups. EEN did not affect incidence of infective complications or gastrointestinal adverse events during the hospital stay; however, EEN was associated with significantly less extent of PHE evolution [maximum absolute PHE (OR 0.822, 95% CI 0.706–0.957, P = 0.012); maximum relative PHE (OR 0.784, 95% CI 0.646–0.952, P = 0.014)]. Conclusion: In our study, EEN was associated with reduced PHE in ICH-patients treated at a NICU. However, this observation did not translate into improved survival or functional outcome at 3 and 12 months

Neutrophil-to-lymphocyte ratio is associated with increased cerebral blood flow velocity in acute bacterial meningitis

In community-acquired bacterial meningitis (CABM) intracranial vascular alterations are devastating complications which are triggered by neuroinflammation and result in worse clinical outcome. The Neutrophil-to-Lymphocyte ratio (NLR) represents a reliable parameter of the inflammatory response. In this study we analyzed the association between NLR and elevated cerebral blood flow velocity (CBFv) in CABM-patients. This study included all (CABM)-patients admitted to a German tertiary center between 2006 and 2016. Patients’ demographics, in-hospital measures, neuroradiological data and clinical outcome were retrieved from institutional databases. CBFv was assessed by transcranial doppler (TCD). Patients’, radiological and laboratory characteristics were compared between patients with/without elevated CBFv. Multivariate-analysis investigated parameters independently associated with elevated CBFv. Receiver operating characteristic(ROC-)curve analysis was undertaken to identify the best cut-off for NLR to discriminate between increased CBFv. 108 patients with CABM were identified. 27.8% (30/108) showed elevated CBFv. Patients with elevated CBFv and normal CBFv, respectively had a worse clinical status on admission (Glasgow Coma Scale: 12 [9–14] vs. 14 [11–15]; p = 0.005) and required more often intensive care (30/30 [100.0%] vs. 63/78 [80.8%]; p = 0.01).The causative pathogen was S. pneumoniae in 70%. Patients with elevated CBFv developed more often cerebrovascular complications with delayed cerebral ischemia (DCI) within hospital stay (p = 0.031). A significantly higher admission-NLR was observed in patients with elevated CBFv (median [IQR]: elevated CBFv:24.0 [20.4–30.2] vs. normal CBFv:13.5 [8.4–19.5]; p  20.9 15/78[19.2%]; p < 0.001). Intracranial vascular complications are common among CABM-patients and are a risk factor for unfavorable outcome at discharge. Elevated NLR is independently associated with high CBFv and may be useful in predicting patients’ prognosis

Location and Timing of Recurrent, Nontraumatic Intracerebral Hemorrhage

IMPORTANCE: : The spatial and temporal distribution of intracerebral hemorrhage (ICH) recurrence are largely unknown. OBJECTIVE: To assess timing and location of recurrent ICH events in relation to the index ICH event (adjacent ICH [adjICH] vs remote ICH [remICH]). DESIGN, SETTING, AND PARTICIPANTS: This cohort study was a pooled analysis of individual cohort studies from 2002 to 2021 among hospital-based European cohorts. Patients with 2 or more clinically distinguishable (≥1 recurrent) small vessel disease-related ICH events were included. Data analysis was performed from December 2023 to December 2024. EXPOSURES: ICH location and underlying small vessel disease type. MAIN OUTCOMES AND MEASURES: The primary outcome was adjICH, defined by anatomical ICH location and side, and the secondary outcome was time to recurrence. Multivariable regression analyses were conducted adjusting for ICH location, cerebral amyloid angiopathy according to Boston 2.0 or simplified Edinburgh criteria, convexity subarachnoid hemorrhage extension, hypertension, and antihypertensive treatment, including an interaction term for hypertension and antihypertensive treatment. RESULTS: Among 733 patients (median [IQR] age, 72.4 [65.2 to 79.0] years; 346 female [47.2%]), there were 1616 ICH events, including 733 index and 883 recurrent ICH events (range, 1 to 6 recurrences) over a median (IQR) follow-up of 2.53 (0.66 to 4.92) years. There were 340 patients (46.4%) with adjICH and 393 patients (53.6%) with remICH. Among recurrent ICH events, there were 476 adjICH events and 407 remICH events. In multivariable regression analyses, lobar index ICH (adjusted odds ratio [aOR], 2.08; 95% CI, 1.32 to 3.27) and cerebral amyloid angiopathy at index ICH (aOR, 2.21; 95% CI, 1.57 to 3.11) were associated with higher odds of adjICH, while cerebellar index ICH was associated with lower odds of adjICH (aOR, 0.25; 95% CI, 0.07 to 0.89). The median (IQR) time to recurrence was 1.25 (0.36 to 3.38) years for adjICH and 2.21 (0.66 to 4.85) years for remICH. Previous lobar or convexity subarachnoid hemorrhage (coefficient, -0.75; 95% CI, -1.25 to -0.25; P = .003 ), adjICH (coefficient, -0.60; 95% CI, -1.02 to -0.18; P = .005), and the number of previous ICH events (coefficient per 1-event increase, -0.62; 95% CI, -0.93 to -0.32; P < .001) were independently associated with a shorter time to recurrence. CONCLUSIONS AND RELEVANCE: This study found that early recurrence and cerebral amyloid angiopathy were associated with adjICH. These findings suggest that regional, tissue-based factors may facilitate recurrence and that identifying and targeting local vasculopathic changes may represent potential novel treatment targets

Etiology, 3-Month Functional Outcome and Recurrent Events in Non-Traumatic Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE Knowledge about different etiologies of non-traumatic intracerebral hemorrhage (ICH) and their outcomes is scarce. METHODS We assessed prevalence of pre-specified ICH etiologies and their association with outcomes in consecutive ICH patients enrolled in the prospective Swiss Stroke Registry (2014 to 2019). RESULTS We included 2,650 patients (mean±standard deviation age 72±14 years, 46.5% female, median National Institutes of Health Stroke Scale 8 [interquartile range, 3 to 15]). Etiology was as follows: hypertension, 1,238 (46.7%); unknown, 566 (21.4%); antithrombotic therapy, 227 (8.6%); cerebral amyloid angiopathy (CAA), 217 (8.2%); macrovascular cause, 128 (4.8%); other determined etiology, 274 patients (10.3%). At 3 months, 880 patients (33.2%) were functionally independent and 664 had died (25.1%). ICH due to hypertension had a higher odds of functional independence (adjusted odds ratio [aOR], 1.33; 95% confidence interval [CI], 1.00 to 1.77; P=0.05) and lower mortality (aOR, 0.64; 95% CI, 0.47 to 0.86; P=0.003). ICH due to antithrombotic therapy had higher mortality (aOR, 1.62; 95% CI, 1.01 to 2.61; P=0.045). Within 3 months, 4.2% of patients had cerebrovascular events. The rate of ischemic stroke was higher than that of recurrent ICH in all etiologies but CAA and unknown etiology. CAA had high odds of recurrent ICH (aOR, 3.38; 95% CI, 1.48 to 7.69; P=0.004) while the odds was lower in ICH due to hypertension (aOR, 0.42; 95% CI, 0.19 to 0.93; P=0.031). CONCLUSIONS Although hypertension is the leading etiology of ICH, other etiologies are frequent. One-third of ICH patients are functionally independent at 3 months. Except for patients with presumed CAA, the risk of ischemic stroke within 3 months of ICH was higher than the risk of recurrent hemorrhage

Telemedizin in der Schlaganfallversorgung – versorgungsrelevant für Deutschland

Background and objective Telemedical stroke networks improve stroke care and provide access to time-dependent acute stroke treatment in predominantly rural regions. The aim is a presentation of data on its utility and regional distribution. Methods The working group on telemedical stroke care of the German Stroke Society performed a survey study among all telestroke networks. Results Currently, 22 telemedical stroke networks including 43 centers (per network: median 1.5, interquartile range, IQR, 1–3) as well as 225 cooperating hospitals (per network: median 9, IQR 4–17) operate in Germany and contribute to acute stroke care delivery to 48 million people. In 2018, 38,211 teleconsultations (per network: median 1340, IQR 319–2758) were performed. The thrombolysis rate was 14.1% (95% confidence interval 13.6–14.7%) and transfer for thrombectomy was initiated in 7.9% (95% confidence interval 7.5–8.4%) of ischemic stroke patients. Financial reimbursement differs regionally with compensation for telemedical stroke care in only three federal states. Conclusion Telemedical stroke care is utilized in about 1 out of 10 stroke patients in Germany. Telemedical stroke networks achieve similar rates of thrombolysis and transfer for thrombectomy compared with neurological stroke units and contribute to stroke care in rural regions. Standardization of network structures, financial assurance and uniform quality measurements may further strengthen the importance of telestroke networks in the future.Hintergrund und Ziel Telemedizinische Schlaganfall-Netzwerke tragen dazu bei, die Schlaganfallversorgung und insbesondere den Zugang zu zeitkritischen Schlaganfalltherapien in vorrangig strukturschwachen, ländlichen Regionen zu gewährleisten. Ziel ist eine Darstellung der Nutzungsfrequenz und regionalen Verteilung dieser Versorgungsstruktur. Methoden Die Kommission „Telemedizinische Schlaganfallversorgung“ der Deutschen Schlaganfall-Gesellschaft führte eine Umfragestudie in allen Schlaganfall-Netzwerken durch. Ergebnisse In Deutschland sind 22 telemedizinische Schlaganfall-Netzwerke aktiv, welche insgesamt 43 Zentren (pro Netzwerk: Median 1,5, Interquartilsabstand [IQA] 1–3) sowie 225 Kooperationskliniken (pro Netzwerk: Median 9, IQA 4–17) umfassen und an einem unmittelbaren Zugang zur Schlaganfallversorgung für 48 Mio. Menschen teilhaben. Im Jahr 2018 wurden 38.211 Telekonsile (pro Netzwerk: Median 1340, IQA 319–2758) durchgeführt. Die Thrombolyserate betrug 14,1 % (95 %-Konfidenzintervall 13,6–14,7 %), eine Verlegung zur Thrombektomie wurde bei 7,9 % (95 %-Konfidenzintervall 7,5–8,4 %) der ischämischen Schlaganfallpatienten initiiert. Das Finanzierungssystem ist uneinheitlich mit einem Vergütungssystem für die Zentrumsleistungen in nur drei Bundesländern. Diskussion Etwa jeder 10. Schlaganfallpatient wird telemedizinisch behandelt. Die telemedizinischen Schlaganfall-Netzwerke erreichen vergleichbar hohe Lyseraten und Verlegungen zur Thrombektomie wie neurologische Stroke-Units und tragen zur Sicherstellung einer flächendeckenden Schlaganfallversorgung bei. Eine netzwerkübergreifende Sicherstellung der Finanzierung und einheitliche Erhebung von Qualitätssicherungsdaten haben das Potenzial diese Versorgungsstruktur zukünftig weiter zu stärken