Prediction error connectivity: A new method for EEG state analysis

Several models have been proposed to explain brain regional and interregional communication, the majority of them using methods that tap the frequency domain, like spectral coherence. Considering brain interareal communication as binary interactions, we describe a novel method devised to predict dynamics and thus highlight abrupt changes marked by unpredictability. Based on a variable-order Markov model algorithm developed in-house for data compression, the prediction error connectivity (PEC) estimates network transitions by calculating error matrices (EMs). We analysed 20 h of EEG signals of virtual networks generated with a neural mass model. Subnetworks changed through time (2 of 5 signals), from normal to normal or pathological states. PEC was superior to spectral coherence in detecting all considered transitions, especially in broad and ripple bands. Subsequently, EMs of real data were classified using a support vector machine in order to capture the transition from interictal to preictal state and calculate seizure risk. A single seizure was randomly selected for training. Through this approach it was possible to establish a threshold that the calculated risk consistently overcame minutes before the events. Using either spectral coherence or PEC we created 1000 models that successfully predicted 6 seizures (100% sensibility), a whole cluster recorded in a patient with hippocampal epilepsy. However, PEC resulted superior to coherence in terms of true seizure free time and amount of false warnings. Indeed, the best PEC model predicted 96% of interictal time (vs. 83% of coherence) of about 20 h of stereo-EEG. This analysis was extended to patients with neo/mesocortical temporal, neocortical frontal, parietal and occipital lobe epilepsy. Again PEC showed high performance, allowing the prediction of 31 events distributed across 10 days with ROC AUCs that reached 98% (average 93 ± 5%) in 6 different patients. Moreover, considering another state transition, PEC could classify and forecast up to 88% (average 85 ± 3%) of the REM phase both in deep and scalp EEG. In conclusion, PEC is a novel approach that relies on pattern analysis in the time-domain. We believe that this method can be successfully employed both for the study of brain connectivity, and also implemented in real-life solutions for seizure detection and prediction

Hemorràgies subaracnoïdals per ruptura d'aneurisma intracranial. Tractament quirúrgic de 100 aneurismes consecutius.

El reconocimiento de la HSA en los Servicios de Urgencias es el primer paso para mejorar los resultados globales de esta grave enfermedad. Deben dirigirse rápidamente a los servicios de neurocirugía y operarlos rápidamente, como mínimo a los enfermos de grado 1, 2 y 3, evitando el temible resangrado. En nuestra serie de 100 aneurismas consecutivos, la decisión de intervención precoz ha supuesto una mejora en los resultados globales, tanto en mortalidad como en morbilidad. En los grados 4 y 5 la decisión quirúrgica precoz o tardía queda abierta a la discusión. La hipertensión-hipervolemia, así como la administración de antagonistas del Ca (nimodipino) han reducido las secuelas producidas por el espasmo arterial. Los resultados obtenidos en el Hospital de Bellvitge, equiparables a otras series mundiales publicadas, muestran unos buenos resultados en el 71 % de los casos, con una mortalidad de un 12 % que se ha reducido a un 6,3 % en los últimos años. La reincorporación laboral ha sido de un 67 % al año de la intervención

Incidental findings on brain MRI of cognitively normal first-degree descendants of patients with Alzheimer's disease: a cross-sectional analysis from the ALFA (Alzheimer and Families) project

Objectives: To describe the prevalence of brain MRI incidental findings (IF) in a cohort of cognitively normal first-degree descendants of patients with Alzheimer's disease (AD). Design: Cross-sectional observational study. Setting: All scans were obtained with a 3.0 T scanner. Scans were evaluated by a single neuroradiologist and IF recorded and categorised. The presence of white matter hyperintensities (WMH) was determined with the Fazekas scale and reported as relevant if ≥2. Participants: 575 participants (45–75 years) underwent high-resolution structural brain MRI. Participants were cognitively normal and scored over the respective cut-off values in all the following neuropsychological tests: Mini-Mental State Examination (≥26), Memory Impairment Screen (≥6), Time Orientation Subtest of the Barcelona Test II (≥68), verbal semantic fluency (naming animals ≥12). Clinical Dementia Rating (CDR) had to be 0. Results: 155 participants (27.0%) presented with at least one IF. Relevant WMH were present in 7.8% of the participants, and vascular abnormalities, cyst and brain volume loss in 10.7%, 3.1% and 6.9% of the study volunteers, respectively. Neoplastic brain findings were found in 2.4% of participants and within these, meningiomas were the most common (1.7%) and more frequently found in women. A positive correlation between increasing age and the presence of IF was found. Additionally, brain atrophy greater than that expected by age was significantly more prevalent in participants without a parental history of AD. Conclusions: Brain MRIs of healthy middle-aged participants show a relatively high prevalence of IF even when study participants have been screened for subtle cognitive alterations. Most of our participants are first-degree descendants of patients with AD, and therefore these results are of special relevance for novel imaging studies in the context of AD prevention in cognitively healthy middle-aged participants.The research leading to these results has received funding from ‘la Caixa’ Foundation. Additional funding was obtained from Fondo de Investigación Sanitaria (FIS), Instituto de Salud Carlos III (ISC-III) under grant PI12/00326 and Barcelona city council under agreement #0724/13 and 0940/16. JDG holds a ‘Ramón y Cajal’ fellowship (RYC-2013-13054)

Incidental findings on brain MRI of cognitively normal first-degree descendants of patients with Alzheimer's disease: a cross-sectional analysis from the ALFA (Alzheimer and Families) project

Objectives: To describe the prevalence of brain MRI incidental findings (IF) in a cohort of cognitively normal first-degree descendants of patients with Alzheimer's disease (AD). Design: Cross-sectional observational study. Setting: All scans were obtained with a 3.0 T scanner. Scans were evaluated by a single neuroradiologist and IF recorded and categorised. The presence of white matter hyperintensities (WMH) was determined with the Fazekas scale and reported as relevant if ≥2. Participants: 575 participants (45–75 years) underwent high-resolution structural brain MRI. Participants were cognitively normal and scored over the respective cut-off values in all the following neuropsychological tests: Mini-Mental State Examination (≥26), Memory Impairment Screen (≥6), Time Orientation Subtest of the Barcelona Test II (≥68), verbal semantic fluency (naming animals ≥12). Clinical Dementia Rating (CDR) had to be 0. Results: 155 participants (27.0%) presented with at least one IF. Relevant WMH were present in 7.8% of the participants, and vascular abnormalities, cyst and brain volume loss in 10.7%, 3.1% and 6.9% of the study volunteers, respectively. Neoplastic brain findings were found in 2.4% of participants and within these, meningiomas were the most common (1.7%) and more frequently found in women. A positive correlation between increasing age and the presence of IF was found. Additionally, brain atrophy greater than that expected by age was significantly more prevalent in participants without a parental history of AD. Conclusions: Brain MRIs of healthy middle-aged participants show a relatively high prevalence of IF even when study participants have been screened for subtle cognitive alterations. Most of our participants are first-degree descendants of patients with AD, and therefore these results are of special relevance for novel imaging studies in the context of AD prevention in cognitively healthy middle-aged participants.The research leading to these results has received funding from ‘la Caixa’ Foundation. Additional funding was obtained from Fondo de Investigación Sanitaria (FIS), Instituto de Salud Carlos III (ISC-III) under grant PI12/00326 and Barcelona city council under agreement #0724/13 and 0940/16. JDG holds a ‘Ramón y Cajal’ fellowship (RYC-2013-13054)

SYLVIUS: A multimodal and multidisciplinary platform for epilepsy surgery

Background and objective: We present SYLVIUS, a software platform intended to facilitate and improve the complex workflow required to diagnose and surgically treat drug-resistant epilepsies. In complex epilepsies, additional invasive information from exploration with stereoencephalography (SEEG) with deep electrodes may be needed, for which the input from different diagnostic methods and clinicians from several specialties is required to ensure diagnostic efficacy and surgical safety. We aim to provide a software platform with optimal data flow among the different stages of epilepsy surgery to provide smooth and integrated decision making. Methods: The SYLVIUS platform provides a clinical workflow designed to ensure seamless and safe patient data sharing across specialities. It integrates tools for stereo visualization, data registration, transfer of electrode plans referred to distinct datasets, automated postoperative contact segmentation, and novel DWI tractography analysis. Nineteen cases were retrospectively evaluated to track modifications from an initial plan to obtain a final surgical plan, using SYLVIUS. Results: The software was used to modify trajectories in all 19 consulted cases, which were then imported into the robotic system for the surgical intervention. When available, SYLVIUS provided extra multimodal information, which resulted in a greater number of trajectory modifications. Conclusions: The architecture presented in this paper streamlines epilepsy surgery allowing clinicians to have a digital clinical tool that allows recording of the different stages of the procedure, in a common multimodal 2D/3D setting for participation of different clinicians in defining and validating surgical plans for SEEG cases.We would like to thank “la Caixa” Banking Foundation for supporting the project. We would also like to thank the epilepsy clinical staff of the Hospital del Mar (Barcelona, Spain) for their guidance and collaboration throughout the project

A randomized trial of deep brain stimulation to the subcallosal cingulate and nucleus accumbens in patients with treatment-refractory, chronic, and severe anorexia nervosa: initial results at 6 months of follow up

Background: The main objective of this study was to assess the safety and efficacy of deep brain stimulation (DBS) in patients with severe anorexia nervosa (AN). Methods: Eight participants received active DBS to the subcallosal cingulate (SCC) or nucleus accumbens (NAcc) depending on comorbidities (affective or anxiety disorders, respectively) and type of AN. The primary outcome measure was body mass index (BMI). Results: Overall, we found no significant difference (p = 0.84) between mean preoperative and postoperative (month 6) BMI. A BMI reference value (BMI-RV) was calculated. In patients that received preoperative inpatient care to raise the BMI, the BMI-RV was defined as the mean BMI value in the 12 months prior to surgery. In patients that did not require inpatient care, the BMI-RV was defined as the mean BMI in the 3-month period before surgery. This value was compared to the postoperative BMI (month 6), revealing a significant increase (p = 0.02). After 6 months of DBS, five participants showed an increase of ≥10% in the BMI-RV. Quality of life was improved (p = 0.03). Three cases presented cutaneous complications. Conclusion: DBS may be effective for some patients with severe AN. Cutaneous complications were observed. Longer term data are needed

Measurement of inclusive J/ψ\psi pair production cross section in pp collisions at s=13\sqrt{s} = 13 TeV

International audienceThe production cross section of inclusive J/$\psi$ pairs in pp collisions at a centre-of-mass energy $\sqrt{s} = 13$ TeV is measured with ALICE. The measurement is performed for J/$\psi$ in the rapidity interval $2.5 0$. The production cross section of inclusive J/$\psi$ pairs is reported to be $10.3 \pm 2.3 {\rm (stat.)} \pm 1.3 {\rm (syst.)}$ nb in this kinematic interval. The contribution from non-prompt J/$\psi$ (i.e. originated from beauty-hadron decays) to the inclusive sample is evaluated. The results are discussed and compared with data

Inclusive and multiplicity dependent production of electrons from heavy-flavour hadron decays in pp and p−-Pb collisions

International audienceMeasurements of the production of electrons from heavy-flavour hadron decays in pp collisions at $\sqrt{s} = 13$ TeV at midrapidity with the ALICE detector are presented down to a transverse momentum ($p_{\rm T}$) of 0.2 GeV$/c$ and up to $p_{\rm T} = 35$ GeV$/c$, which is the largest momentum range probed for inclusive electron measurements in ALICE. In p$-$Pb collisions, the production cross section and the nuclear modification factor of electrons from heavy-flavour hadron decays are measured in the $p_{\rm T}$ range $0.5 < p_{\rm T} < 26$ GeV$/c$ at $\sqrt{s_{\rm NN}} = 8.16$ TeV. The nuclear modification factor is found to be consistent with unity within the statistical and systematic uncertainties. In both collision systems, first measurements of the yields of electrons from heavy-flavour hadron decays in different multiplicity intervals normalised to the multiplicity-integrated yield (self-normalised yield) at midrapidity are reported as a function of the self-normalised charged-particle multiplicity estimated at midrapidity. The self-normalised yields in pp and p$-$Pb collisions grow faster than linear with the self-normalised multiplicity. A strong $p_{\rm T}$ dependence is observed in pp collisions, where the yield of high-$p_{\rm T}$ electrons increases faster as a function of multiplicity than the one of low-$p_{\rm T}$ electrons. The measurement in p$-$Pb collisions shows no $p_{\rm T}$ dependence within uncertainties. The self-normalised yields in pp and p$-$Pb collisions are compared with measurements of other heavy-flavour, light-flavour, and strange particles, and with Monte Carlo simulations

Observation of medium-induced yield enhancement and acoplanarity broadening of low-pTp_\mathrm{T} jets from measurements in pp and central Pb−-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}}=5.02 TeV

International audienceThe ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high $p_{\rm T}$) hadron trigger in proton$-$proton and central Pb$-$Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb$-$Pb collisions. Recoil jet distributions are reported for jet resolution parameter $R=0.2$, 0.4, and 0.5 in the range $7 < p_{\rm T,jet} < 140$ GeV$/c$ and trigger$-$recoil jet azimuthal separation $\pi/2 < \Delta\varphi < \pi$. The measurements exhibit a marked medium-induced jet yield enhancement at low $p_{\rm T}$ and at large azimuthal deviation from $\Delta\varphi\sim\pi$. The enhancement is characterized by its dependence on $\Delta\varphi$, which has a slope that differs from zero by 4.7$\sigma$. Comparisons to model calculations incorporating different formulations of jet quenching are reported. These comparisons indicate that the observed yield enhancement arises from the response of the QGP medium to jet propagation

Probing the Chiral Magnetic Wave with charge-dependent flow measurements in Pb-Pb collisions at the LHC

International audienceThe Chiral Magnetic Wave (CMW) phenomenon is essential to provide insights into the strong interaction in QCD, the properties of the quark-gluon plasma, and the topological characteristics of the early universe, offering a deeper understanding of fundamental physics in high-energy collisions. Measurements of the charge-dependent anisotropic flow coefficients are studied in Pb-Pb collisions at center-of-mass energy per nucleon-nucleon collision $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV to probe the CMW. In particular, the slope of the normalized difference in elliptic ($v_{2}$) and triangular ($v_{3}$) flow coefficients of positively and negatively charged particles as a function of their event-wise normalized number difference, is reported for inclusive and identified particles. The slope $r_{3}^{\rm Norm}$ is found to be larger than zero and to have a magnitude similar to $r_{2}^{\rm Norm}$, thus pointing to a large background contribution for these measurements. Furthermore, $r_{2}^{\rm Norm}$ can be described by a blast wave model calculation that incorporates local charge conservation. In addition, using the event shape engineering technique yields a fraction of CMW ($f_{\rm CMW}$) contribution to this measurement which is compatible with zero. This measurement provides the very first upper limit for $f_{\rm CMW}$, and in the 10-60% centrality interval it is found to be 26% (38%) at 95% (99.7%) confidence level