Hemodynamic causes of deterioration in acute ischemic stroke

SummaryNeurological deterioration can occur in 13–38% of patients with acute ischemic stroke due to hemodynamic and non-hemodynamic causes. Several non-hemodynamic mechanisms can lead to ischemic lesion extension and subsequent neurological worsening, including infections, cerebral edema, hemorrhagic conversion of infarction and metabolic disorders. The most common hemodynamic causes related to infarct expansion, leading to neurologic deterioration in the setting of acute cerebral ischemia are the following: (i) cardiac complications, (ii) arterial reocclusion, (iii) intracranial arterial steal phenomenon, and (iv) cerebral microembolization. The present review aims to address the underlying mechanisms and potential clinical implications of the hemodynamic causes of neurological deterioration in patients with acute cerebral ischemia. The contribution of neurosonology in detection of changes in cerebral hemodynamics in real-time are also going to be discussed. Finally, potential treatment strategies for specific causes of hemodynamic deterioration in acute ischemic stroke patients are reported

Learning to Fulfill the User Demands in 5G-enabled Wireless Networks through Power Allocation: a Reinforcement Learning approach

The goal of the study presented in this paper is to evaluate the performance of a proposed Reinforcement Learning (RL) power allocation algorithm. The algorithm follows a demand-driven power adjustment approach aiming at maximizing the number of users inside a coverage area that experience the requested throughput to accommodate their needs. In this context, different Quality of Service (QoS) classes, corresponding to different throughput demands, have been taken into account in various simulation scenarios. Considering a realistic network configuration, the performance of the RL algorithm is tested under strict user demands. The results suggest that the proposed modeling of the RL parameters, namely the state space and the rewarding system, is promising when the network controller attempts to fulfill the user requests by regulating the power of base stations. Based on comparative simulations, even for strict demands requested by multiple users (2.5 – 5 Mbps), the proposed scheme achieves a performance rate of about 96%

Multiple sclerosis presented as clinically isolated syndrome: the need for early diagnosis and treatment

Sigliti-Henrietta Pelidou, Sotirios Giannopoulos, Sotiria Tzavidi, Georgios Lagos, Athanassios P KyritsisDepartment of Neurology, University of Ioannina School of Medicine, GreeceObjective: To aid in the timely diagnosis of patients who present with clinically isolated syndrome (CIS).Patients and methods: We studied 25 patients (18 women, 7 men), originally presented in our clinic with a CIS suggestive of multiple sclerosis (MS). All patients underwent the full investigation procedure including routine tests, serology, cerebrospinal fluid (CSF) examinations, evoked potentials (EPs), and magnetic resonance imaging (MRI) of brain and cervical spinal cord. Patients were imaged at baseline, and every three months thereafter up to a year.Results: The CIS was consisted of optic neuritis in 12 cases, incomplete transverse myelitis (ITM) in 7 cases, Lhermitte sign in 2 cases, internuclear ophthalmoplegia (INO) in 2 cases, mild brainstem syndrome in 1 case, and tonic-clonic seizures in 1 case. Using the baseline and three-month scans 18/25 (72%) patients developed definite MS in one year of follow up while 7 (28%) had no further findings during this observation period. Immunomodulatory treatments were applied to all definite MS patients.Conclusion: In light of new treatments available, MRIs at 3 month intervals are helpful to obtain the definite diagnosis of MS as early as possible.Keywords: multiple sclerosis, clinically isolated syndrome, optic neuritis, transverse myeliti

Coexistence of gastrointestinal stromal tumor (GIST) and colorectal adenocarcinoma: A case report

<p>Abstract</p> <p>Background</p> <p>Gastrointestinal stromal tumors (GIST) represent the most common mesenchymal tumors of the digestive tract. Over the last ten years the management of GISTs has dramatically altered but their coexistence with other gasrointesinal tumors of different histogenesis presents a special interest. The coexistence of GISTs with other primaries is usually discovered incidentally during GI surgery for carcinomas.</p> <p>Case presentation</p> <p>We present here, a case of a 66-year-old patient with intestinal GIST and a synchronous colorectal adenocarcinoma discovered incidentally during surgical treatment of the recurrent GIST. Immunohistochemical examination revealed the concurrence of histologically proved GIST (strongly positive staining for c-kit, vimentin, SMA, and focal positive in S-100, while CD-34 was negative) and Dukes Stage C, (T3, N3, M0 according the TNM staging classification of colorectal cancer).</p> <p>Conclusion</p> <p>The coexistence of GIST with either synchronous or metachronous colorectal cancer represents a phenomenon with increasing number of relative reports in the literature the last 5 years. In any case of GIST the surgeon should be alert to recognize a possible coexistent tumor with different histological origin and to perform a thorough preoperative and intraoperative control. The correct diagnosis before and at the time of the surgical procedure is the cornerstone that secures the patients' best prognosis.</p

Outcomes of delayed chest closure after congenital heart surgery in neonates

We present the outcomes of delayed chest closure in neonates who underwent congenital heart surgery under cardiopulmonary bypass. Eighty-one consecutive neonatal patients (age ≤ 28 days) with congenital heart diseases who underwent heart operations and after surgery, chest remained open in the intensive care unit until DCC. Correction of transposition of the great arteries pathology was the most common surgical procedure (48.1% of patients). Median sternal closure time from surgery was 3 (2-4) days. Median age of neonates was 9 (5-12) days. In addition, in 4 cases (4.9%) there was secretion from the surgical site after DCC and after taking cultures, in 2 (2.4%) of the cases a pathogen was identified. Multivariable linear regression analysis (adjusted to gender and CPB) showed that only the age-predicted the sternum closure time (β=-0.09, 95%CI: - 0.16 to -0.02, p=0.02). In-hospital mortality was 6 (7.4%) patients. Although the DCC in neonates who underwent CHD surgical correction was related to a high mortality rate, only the age of neonates predicted the sternum closure time in the ICU

Intravenous thrombolysis for acute ischemic stroke in Greece: the Safe Implementation of Thrombolysis in Stroke registry 15-year experience

Background: Intravenous thrombolysis (IVT) remains the only approved systemic reperfusion treatment for acute ischemic stroke (AIS), however there are scarce data regarding outcomes and complications of IVT in Greece. We evaluated safety and efficacy outcomes of IVT for AIS in Greece using the Safe Implementation of Thrombolysis in Stroke: International Stroke Thrombolysis Register (SITS-ISTR) dataset. Methods: All AIS patients treated with IVT in Greece between December 2002 and July 2017 and recorded in the SITS-ISTR were evaluated. Demographics, risk factors, baseline stroke severity [defined using National Institutes of Health Stroke Scale (NIHSS)], and onset-to-treatment time (OTT) were recorded. Safety outcomes included symptomatic intracranial hemorrhage (sICH) and 3-month mortality rates. The efficacy outcomes evaluated a reduction in baseline NIHSS score at 2 and 24 h following IVT onset, 3-month favorable functional outcome [FFO; modified Rankin scale (mRS) scores of 0-1] and 3-month functional independence (FI; mRS-scores of 0-2). The safety and efficacy outcomes were assessed comparatively with previously published data from SITS national and international registries. Results: A total of 523 AIS patients were treated with IVT in 12 Greek centers participating in the SITS-ISTR during the study period (mean age 62.4 ± 12.7; 34.6% women; median baseline NIHSS score: 11 points; median OTT: 150 min). The rates of sICH were 1.4%, 2.3%, and 3.8% according to the SIST-MOST, ECASS II, and NINDS criteria respectively. The median reduction in NIHSS score at 2 and 24 h was 3 [interquartile range (IQR): 1-5] and 5 (IQR: 2-8) points respectively. The 3-month FI, FFO and mortality were 66.5%, 55.6% and 7.9%. All safety and efficacy outcomes were comparable with available data from SITS-ISTR in other European countries. Conclusions: Our study underscores the safety and efficacy of IVT for AIS in Greece. Additional action is necessary in order to increase the availability of IVT in the Greek population and to include more centers in the SITS-ISTR

A reference architecture for cloud-edge meta-operating systems enabling cross-domain, data-intensive, ML-assisted applications: architectural overview and key concepts

Future data-intensive intelligent applications are required to traverse across the cloudto-edge-to-IoT continuum, where cloud and edge resources elegantly coordinate, alongside sensor networks and data. However, current technical solutions can only partially handle the data outburst associated with the IoT proliferation experienced in recent years, mainly due to their hierarchical architectures. In this context, this paper presents a reference architecture of a meta-operating system (RAMOS), targeted to enable a dynamic, distributed and trusted continuum which will be capable of facilitating the next-generation smart applications at the edge. RAMOS is domain-agnostic, capable of supporting heterogeneous devices in various network environments. Furthermore, the proposed architecture possesses the ability to place the data at the origin in a secure and trusted manner. Based on a layered structure, the building blocks of RAMOS are thoroughly described, and the interconnection and coordination between them is fully presented. Furthermore, illustration of how the proposed reference architecture and its characteristics could fit in potential key industrial and societal applications, which in the future will require more power at the edge, is provided in five practical scenarios, focusing on the distributed intelligence and privacy preservation principles promoted by RAMOS, as well as the concept of environmental footprint minimization. Finally, the business potential of an open edge ecosystem and the societal impacts of climate net neutrality are also illustrated.For UPC authors: this research was funded by the Spanish Ministry of Science, Innovation and Universities and FEDER, grant number PID2021-124463OB-100.Peer ReviewedPostprint (published version

Self-reported risk of obstructive sleep apnea syndrome, and awareness about it in the community of 4 insular complexes comprising 41 Greek Islands

Obstructive Sleep Apnea Syndrome (OSAS) is a chronic disease that significantly increases morbidity and mortality of the affected population. There is lack of data concerning the OSAS prevalence in the insular part of Greece. The purpose of this study was to investigate the self-reported prevalence of OSAS in 4 Greek insular complexes comprising 41 islands, and to assess the awareness of the population regarding OSAS and its diagnosis. Our study comprised 700 participants from 41 islands of the Ionian, Cyclades, Dodecanese and Northeast Aegean island complexes that were studied by means of questionnaires via a telephone randomized survey (responsiveness rate of 25.74%). Participants were assessed by the Berlin Questionnaire (BQ) for evaluation of OSA risk, by the Epworth Sleepiness Scale (ESS) for evaluation of excessive daytime sleepiness, and by 3 questions regarding the knowledge and diagnosis of OSAS. The percentage of participants at high risk according to BQ was 27.29% and the percentage of people who were at high risk according to ESS was 15.43%. A percentage of 6.29% of the population was at high risk for OSAS (high risk both in BQ and ESS). A high percentage of 73.43%, were aware of OSAS as a syndrome however a significantly less percentage (28.00%) was aware of how a diagnosis of OSAS is established. The community prevalence of OSAS in Greek islands in combination with the low-level awareness of the OSAS diagnostic methods highlights the need for development of health promotion programs aiming at increasing the detection of patients at risk while increasing the awareness of OSAS

Neuronal nicotinic acetylcholine receptor antibodies in autoimmune central nervous system disorders

BackgroundNeuronal nicotinic acetylcholine receptors (nAChRs) are abundant in the central nervous system (CNS), playing critical roles in brain function. Antigenicity of nAChRs has been well demonstrated with antibodies to ganglionic AChR subtypes (i.e., subunit α3 of α3β4-nAChR) and muscle AChR autoantibodies, thus making nAChRs candidate autoantigens in autoimmune CNS disorders. Antibodies to several membrane receptors, like NMDAR, have been identified in autoimmune encephalitis syndromes (AES), but many AES patients have yet to be unidentified for autoantibodies. This study aimed to develop of a cell-based assay (CBA) that selectively detects potentially pathogenic antibodies to subunits of the major nAChR subtypes (α4β2- and α7-nAChRs) and its use for the identification of such antibodies in “orphan” AES cases.MethodsThe study involved screening of sera derived from 1752 patients from Greece, Turkey and Italy, who requested testing for AES-associated antibodies, and from 1203 “control” patients with other neuropsychiatric diseases, from the same countries or from Germany. A sensitive live-CBA with α4β2-or α7-nAChR–transfected cells was developed to detect antibodies against extracellular domains of nAChR major subunits. Flow cytometry (FACS) was performed to confirm the CBA findings and indirect immunohistochemistry (IHC) to investigate serum autoantibodies’ binding to rat brain tissue.ResultsThree patients were found to be positive for serum antibodies against nAChR α4 subunit by CBA and the presence of the specific antibodies was quantitatively confirmed by FACS. We detected specific binding of patient‐derived serum anti‐nAChR α4 subunit antibodies to rat cerebellum and hippocampus tissue. No serum antibodies bound to the α7-nAChR-transfected or control-transfected cells, and no control serum antibodies bound to the transfected cells. All patients positive for serum anti‐nAChRs α4 subunit antibodies were negative for other AES-associated antibodies. All three of the anti‐nAChR α4 subunit serum antibody-positive patients fall into the AES spectrum, with one having Rasmussen encephalitis, another autoimmune meningoencephalomyelitis and another being diagnosed with possible autoimmune encephalitis.ConclusionThis study lends credence to the hypothesis that the major nAChR subunits are autoimmune targets in some cases of AES and establishes a sensitive live-CBA for the identification of such patients