Machine learning for a combined electroencephalographic anesthesia index to detect awareness under anesthesia

Spontaneous electroencephalogram (EEG) and auditory evoked potentials (AEP) have been suggested to monitor the level of consciousness during anesthesia. As both signals reflect different neuronal pathways, a combination of parameters from both signals may provide broader information about the brain status during anesthesia. Appropriate parameter selection and combination to a single index is crucial to take advantage of this potential. The field of machine learning offers algorithms for both parameter selection and combination. In this study, several established machine learning approaches including a method for the selection of suitable signal parameters and classification algorithms are applied to construct an index which predicts responsiveness in anesthetized patients. The present analysis considers several classification algorithms, among those support vector machines, artificial neural networks and Bayesian learning algorithms. On the basis of data from the transition between consciousness and unconsciousness, a combination of EEG and AEP signal parameters developed with automated methods provides a maximum prediction probability of 0.935, which is higher than 0.916 (for EEG parameters) and 0.880 (for AEP parameters) using a cross-validation approach. This suggests that machine learning techniques can successfully be applied to develop an improved combined EEG and AEP parameter to separate consciousness from unconsciousness

Childhood-Onset Epileptic Encephalopathy Associated With Isolated Focal Cortical Dysplasia and a Novel TSC1 Germline Mutation

Tuberous sclerosis complex (TSC) is an autosomal-dominant inheritable neurocutaneous disease due to mutations within the TSC1 and TSC2 genes. Many patients present with West syndrome, a severe epilepsy syndrome characterized by the triad of infantile spasms, an interictal electroencephalogram (EEG) pattern termed hypsarrhythmia (continuous slow activity with an amplitude higher than 300 mu V and multiregional spikes/polyspikes/sharp waves) and developmental regression. In this study, we report on a previously healthy patient with positive family history of epilepsy with new-onset epileptic encephalopathy at the age of 9 years. Clinical signs alone were not sufficient to establish the diagnosis of TSC but epilepsy panel screening revealed a novel frameshift mutation (c.90delA;p.Glu31Argfs*12) within the TSC1 gene. Segregation gene analysis detected the same mutation in the mother. Cranial magnetic resonance imaging (MRI) studies from the index patient and his mother revealed a similar pattern of isolated subcortical white matter lesions resembling most likely focal cortical dysplasia (FCD) type IIb. In summary, in these 2 related patients, a novel TSC1 frameshift mutation was associated with an isolated FCD type IIb in the absence of further CNS abnormalities usually encountered in patients with TSC, fostering our understanding of the broad mutation spectra in the TSC1 gene and the close relationship between cortical tubers and FCD type IIb

Effects of a reduction of the number of electrodes in the EEG montage on the number of identified seizure patterns

Continuous EEG monitoring (cEEG) is frequently used in neurocritical care. The detection of seizures is one of the main objectives. The placement of the EEG electrodes is time consuming, therefore a reduced montage might lead to an increased availability in the ICU setting. It is unknown whether such a reduction of electrodes reduces the number of seizure patterns that are detected. A total of 95 seizure and 95 control EEG sequences from a pediatric epilepsy monitoring unit (EMU) were anonymized and reduced to an eight-lead montage. Two experts evaluated the recordings and the seizure detection rates using the reduced and the full montage were compared. Sensitivity and specificity for the seizure detection were calculated using the original EMU findings as gold standard. The sensitivity to detect seizures was 0.65 for the reduced montage compared to 0.76 for the full montage (p = 0.031). The specificities (0.97 and 0.96) were comparable (p = 1). A total of 4/9 (44%) of the generalized, 12/44 (27%) of the frontal, 6/14 (43%) of the central, 0/1 (0%) of the occipital, 6/20 (30%) of the temporal, and 5/7 (71%) of the parietal seizure patterns were not detected using the reduced montage. The median time difference between the onset of the seizure pattern in the full and reduced montage was 0.026s (IQR 5.651s). In this study the reduction of the EEG montage from 21 to eight electrodes reduced the sensitivity to detect seizure patterns from 0.76 to 0.65. The specificity remained virtually unchanged

Cognitive performance and behavior across idiopathic/genetic epilepsies in children and adolescents

We investigated the cognitive and behavioral profile of three distinct groups of epilepsies with a genetic Background: for intergroup differences: (1) idiopathic/genetic generalized epilepsies (IGE/GGE group);(2) idiopathic focal epilepsies (IFE group);and (3) epilepsies with proven or strongly suggested monogenic or structural/numeric chromosomal etiology (genetic epilepsies, GE group). Cognitive (total IQ and subcategories) and behavioral parameters (CBCL) were assessed at the tertiary epilepsy center of the University of Munich (Germany). We used ANOVA with post-hoc Bonferroni-correction to explore significant mean differences and Fisher's exact test for significant proportional differences of intelligence impairment and behavioral problems. 126 (56 IGE/GGE, 26 IFE, 44 GE) patients were available. Total IQ was 89.0 +/- 15.9 (95% CI 84.5-93.4) for IGE/GGE, 94.8 +/- 18.1 (95% CI 87.3-102.3) for IFE and 76.4 +/- 22.4 (95% CI 67.6-85.3) for GE (p=0.001). The same trend was significant for all but one IQ subcategory. The rate of patients with an intelligence impairment (total IQ<70) was higher for GE (40%) than for IGE/GGE (14%) and for IFE (7%) patients (p=0.033). There were no significant differences between groups for behavior scores and behavioral problems. This study shows that the current ILAE classification of epilepsies with genetic etiology creates a heterogeneous group of patients with respect to cognitive performance but not behavior. These findings may help in further delineating epilepsies as regards cognitive performance, notwithstanding their closely related etiological classification

Recurrence of Hepatocellular Carcinoma After Liver Transplantation is Associated with Episodes of Acute Rejections.

Purpose The impact of acute rejection (AR) after liver transplantation (LT) for hepatocellular carcinoma (HCC) on patient outcome is uncertain. This aim of this study is to investigate whether AR is associated with HCC relapse and overall survival. Patients and Methods Patients undergoing LT for HCC between 2001 and 2015 were retrospectively analyzed with regard to histopathological proven AR within the median time until recurrence. Cox's regression analysis was conducted revealing risk factors for HCC recurrence. Results HCC recurred in 47 of 252 analyzed patients with a median time to recurrence of 20 months. Patients with AR (28.6%) had a significantly higher frequency of recurrence compared to patients without AR (13.0%, p=0.002). Multiple Cox regression analyses identified AR within 20 months to be an independent risk factor for HCC recurrence both as dichotomized (HR=2.91, 95%CI: 1.30-6.53; p=0.009) and as a continuous variable (HR=1.81, 95%CI: 1.28-2.54; p=0.001). HCC recurrence and AR were associated with higher grades of liver fibrosis one year after LT, when compared to patients without AR (p=0.019). Conclusion Our results demonstrate an association of AR with HCC recurrence after LT with implications for intervals of monitoring in tumor surveillance. Graft fibrosis and immune mechanisms are potentially related and causal interactions are worth further investigation

Recanalization strategies in childhood stroke in Germany

Childhood arterial ischemic stroke (CAIS) is a rare event. Diverse etiologies, risk factors, symptoms and stroke mimics hamper obtaining a fast diagnosis and implementing immediate recanalization strategies. Over a period of 3~years (2015-2017), the data of 164 pediatric patients (> 28~days of life-18~years) with a first episode of AIS were submitted to a hospital-based nationwide surveillance system for rare disorders (ESPED). We report a subgroup analysis of patients who have undergone recanalization therapy and compare these data with those of the whole group. Twenty-eight patients (17%) with a median age of 12.2~years (range 3.3-16.9) received recanalization therapy. Hemiparesis, facial weakness and speech disturbance were the main presenting symptoms. The time from onset of symptoms to confirmation of diagnosis was significantly shorter in the intervention group (4.1~h vs. 20.4~h, p ≤ 0.0001). Only in one patient occurred a minor bleed. Cardiac disease as predisposing risk factor was more common in the recanalization group. Recanalization therapies are feasible and increasingly applied in children with AIS. High awareness, timely diagnosis and a large amount of expertise may improve time to treatment and make hyperacute therapy an option for more patients

Solid organ transplantation programs facing lack of empiric evidence in the COVID‐19 pandemic: A By‐proxy Society Recommendation Consensus approach

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has a drastic impact on national health care systems. Given the overwhelming demand on facility capacity, the impact on all health care sectors has to be addressed. Solid organ transplantation represents a field with a high demand on staff, intensive care units, and follow-up facilities. The great therapeutic value of organ transplantation has to be weighed against mandatory constraints of health care capacities. In addition, the management of immunosuppressed recipients has to be reassessed during the ongoing coronavirus disease 2019 (COVID-19) pandemic. In addressing these crucial questions, transplant physicians are facing a total lack of scientific evidence. Therefore, the aim of this study was to offer an approach of consensus-based guidance, derived from individual information of 22 transplant societies. Key recommendations were extracted and the degree of consensus among different organizations was calculated. A high degree of consensus was found for temporarily suspending nonurgent transplant procedures and living donation programs. Systematic polymerase chain reaction-based testing of donors and recipients was broadly recommended. Additionally, more specific aspects (eg, screening of surgical explant teams and restricted use of marginal donor organs) were included in our analysis. This study offers a novel approach to informed guidance for health care management when a priori no scientific evidence is available