Eliane Albuisson

Vertical and horizontal smooth pursuit eye movements in children with developmental coordination disorder.

Our aim was to study horizontal and vertical smooth pursuit eye movements in children with developmental coordination disorder (DCD).

Prognostic Value of Estimated Plasma Volume in Heart Failure

OBJECTIVES The purpose of this study was to assess the prognostic value of the estimation of plasma volume or of its variation beyond clinical examination in a post-hoc analysis of EPHESUS (Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study). BACKGROUND Assessing congestion after discharge is challenging but of paramount importance to optimize patient management and to prevent hospital readmissions. METHODS The present analysis was performed in a subset of 4,957 patients with available data (within a full dataset of 6,632 patients). The study endpoint was cardiovascular death or hospitalization for heart failure (HF) between months 1 and 3 after post-acute myocardial infarction HF. Estimated plasma volume variation (ΔePVS) between baseline and month 1 was estimated by the Strauss formula, which includes hemoglobin and hematocrit ratios. Other potential predictors, including congestion surrogates, hemodynamic and renal variables, and medical history variables, were tested. An instantaneous estimation of plasma volume at month 1 was defined and also tested. RESULTS Multivariate analysis was performed with stepwise logistic regression. ΔePVS was selected in the model (odds ratio: 1.01; p = 0.004). The corresponding prognostic gain measured by integrated discrimination improvement was significant (7.57%; p = 0.01). Nevertheless, instantaneous estimation of plasma volume at month 1 was found to be a better predictor than ΔePVS. CONCLUSIONS In HF complicating myocardial infarction, congestion as assessed by the Strauss formula and an instantaneous derived measurement of plasma volume provided a predictive value of early cardiovascular events beyond routine clinical assessment. Prospective trials to assess congestion management guided by this simple tool to monitor plasma volume are warranted.

Performance of asialotransferrin in detecting alcohol abuse.

BACKGROUND The spectrum of alcohol use disorders covers hazardous use, alcohol abuse, and alcohol dependence. The present study evaluated the performance of asialotransferrin, a newly proposed biomarker for alcohol use disorders, in detecting alcohol abuse and alcohol dependence. METHOD A 4-month trial was conducted in three groups of participants: alcohol abusers and alcohol-dependent patients, as defined in DSM-IV, and a control group. Asialotransferrin was assayed by capillary zone electrophoresis. RESULTS Asialotransferrin demonstrated a sensitivity of 0.34 and a specificity of 1.00 for alcohol abuse. The sensitivity of asialotransferrin increased to 0.57 in alcohol-dependent patients. CONCLUSION Despite the high specificity of asialotransferrin in alcohol use disorders, its sensitivity is too low to make it a useful marker of alcohol abuse.

Vertical and horizontal smooth pursuit eye movements in children: A neuro-developmental study

An evaluation of eye movements is very useful in neurological disorders but is complicated by issues such as maturation and lack of normative data in children. In order to address these issues we studied smooth pursuit eye movements of 65 normal children aged 7-11 years old. The gain of horizontal smooth pursuit (HSP) was higher than the gain of the vertical smooth pursuit (SP) and this difference had a statistical tendency to disappear with aging from 7 to 11 years. These data suggest that, in the cerebral regions involved in the control of SP, i.e. posterior parietal and superior temporal lobe regions, the networks for VSP mature latter than those for HSP.

Visual neurophysiological dysfunction in infants exposed to hydroxychloroquine in utero.

Sir, We read with interest the report by Renault et al. on visual neurophysiological dysfunctions in infants exposed to hydroxychloroquine (HCQ) in utero (1). Indeed, data on that topic are scare and further studies are needed. However, major concerns arise regarding the methodology used. Mesopic ERG is not recommended by the International Society of Electrophysiology for Vision (ISCEV) and should not be used. ISCEV guidelines include only scotopic and photopic ERG (2). The authors have compared their results with control groups tested in 1996 for the ERG and in 1977 for the VEP. Thus, the authors had to mention that their techniques are the same as those of the earlier studies and that the flash intensity has been controlled and did not change during this period. Because, if the intensity of the flash had changed, the amplitude of the ERG would have also changed and could simply explain that there is a statistical difference between the infants tested in 2009 and those tested in 1996. With regard to the results, some infants in the study were premature. The authors stated in their previous study ‘the amplitude of these waves increased considerably throughout the period studied’ meaning during first years of life. Many electrophysiologists have concerns regarding the validity of flash-ERG in very young children and consider that abnormal results should be interpreted with caution and should be confirmed by an additional method. Furthermore, the authors say, ‘in order to avoid introducing the bias of maturity, not any ERG and VEP was carried out before the corrected age of 40 weeks’. This does not eliminate the possibility that any abnormalities found were the consequences of prematurity (3). The authors write, ‘statistically, duration of pregnancy – exposition to HCQ – was 38.6 weeks for infants with normal ERG vs 35.6 weeks for infants with abnormal ERG (Mann–Whitney test, p = 0.003). Mean corrected age at first ERG recording was not significantly different in infants with normal ERG (382 days) from infants with abnormal ERG (350 days) (Mann–Whitney test, p = 0.15)’. We understand that infants with abnormal ERG were probably premature (explaining the lower exposure to HCQ). In addition, infants with abnormal ERG were younger, and it has been established by the authors that the amplitude of the aand b-waves increases considerably with age (ref 9). As both their mothers’ diseases and then prematurity may affect foetuses, a control group must be carefully defined and should include pregnant patients with connective tissue diseases, but without HCQ treatment. Moreover, the analysis should be blind. In conclusion, significant discrepancies between the present study in which a quarter of the infants have abnormal results and previous published studies with much more reassuring data and robust methodology are probably explained by the faultiness of the method used. This is important in view of the fears that will result from these results and, thus, of their clinical consequences, i.e. increased risk of SLE flare, if HCQ is no longer given to pregnant patients (4).

Association Between Regular Cannabis Use and Ganglion Cell Dysfunction

Importance Because cannabis use is a major public health concern and cannabis is known to act on central neurotransmission, studying the retinal ganglion cells in individuals who regularly use cannabis is of interest. Objective To determine whether the regular use of cannabis could alter the function of retinal ganglion cells in humans. Design, Setting, and Participants For this case-control study, individuals who regularly use cannabis, as well as healthy controls, were recruited, and data were collected from February 11 to October 28, 2014. Retinal function was used as a direct marker of brain neurotransmission abnormalities in complex mental phenomena. Main Outcomes and Measures Amplitude and implicit time of the N95 wave on results of pattern electroretinography. Results Twenty-eight of the 52 participants were regular cannabis users (24 men and 4 women; median age, 22 years [95% CI, 21-24 years]), and the remaining 24 were controls (20 men and 4 women; median age, 24 years [95% CI, 23-27 years]). There was no difference between groups in terms of age (P = .13) or sex (P = .81). After adjustment for the number of years of education and alcohol use, there was a significant increase for cannabis users of the N95 implicit time on results of pattern electroretinography (median, 98.6 milliseconds [95% CI, 93.4-99.5]) compared with controls (median, 88.4 milliseconds [95% CI, 85.0-91.1]), with 8.4 milliseconds as the median of the differences (95% CI, 4.9-11.5; P < .001, Wald logistic regression). A receiver operating characteristic curve analysis (area under the curve, 0.84 [95% CI, 0.73-0.95]; P < .001) revealed, for a cutoff value of 91.13 milliseconds, a sensitivity of 78.6% (95% CI, 60.5%-89.8%) and a specificity of 75.0% (95% CI, 55.1%-88.0%) for correctly classifying both cannabis users and controls in their corresponding group. The positive predictive value was 78.6% (95% CI, 60.5%-89.8%), and the negative predictive value was 75.0% (95% CI, 55.1%-88.0%). Conclusions and Relevance Our results demonstrate a delay in transmission of action potentials by the ganglion cells in regular cannabis users, which could support alterations in vision. Our findings may be important from a public health perspective since they could highlight the neurotoxic effects of cannabis use on the central nervous system as a result of how it affects retinal processing.

High Versus Low Blood-Pressure Target in Experimental Ischemic Prolonged Cardiac Arrest Treated with Extra Corporeal Life Support

Background: There is currently no recommendation for the mean arterial pressure target in the particular setting of Extracorporeal Cardiopulmonary Resuscitation (ECPR) in the first hours following cardiogenic shock complicated by cardiac arrest. This study aimed to assess the effects of two different levels of mean arterial pressure on macrocirculatory, microcirculatory, and metabolic functions. Design: Randomized animal study. Setting: University research laboratory. Intervention: Ventricular fibrillation was induced in 14 male pigs by surgical ligature of the interventricular coronary artery. After 20 min of cardiopulmonary resuscitation, Extracorporeal Life Support (ECLS) was initiated to restore circulatory flow. Thereafter, animals were randomly allocated to a high mean arterial pressure group (High-MAP, 80–85 mm Hg) or to a standard mean arterial pressure group (Standard-MAP, 65–70 mm Hg). Assessments conducted at baseline, immediately following and 6 h after ECLS initiation were focused on lactate evolution, amount of infused fluid, and microcirculatory parameters. Results: There was no significant difference between the two groups at the time of ECLS initiation and at 6 h with regard to lactate levels (High-MAP vs. Standard-MAP: 8.8 [6.7–12.9] vs. 9.6 [9.1–9.8] mmol·l−1, P = 0.779 and 8.9 [4.3–11.1] vs. 3.3 [2.4–11] mmol·l−1, P = 0.603). Infused fluid volume did not significantly differ between the two groups (4,000 [3,500–12,000] vs. 5,000 [2,500–18,000] mL, P = 0.977). There was also no significant difference between the two groups regarding renal and liver functions, and sublingual capillary microvascular flow index assessed by Sidestream Dark Field imaging. Conclusion: Compared with a standard mean arterial pressure regimen, targeting a high mean arterial pressure in the first hours of an experimental ECPR model did not result in any hemodynamic improvement nor in a decrease in the amount of infused fluid.

Accuracy and results of photopic flash electroretinogram performed with skin electrodes in infants.

Purpose As it is not always possible to use corneal electrodes for recording electroretinograms (ERG) in children, it is necessary to check the feasibility of performing ERG with skin electrodes and to try to establish normative data. Methods Fifty-one healthy children (aged 7-11 years) were recruited. Cone ERG and 30-Hz flicker ERG were recorded with one active skin electrode positioned over the lower eyelid and a reference electrode at the outer canthus of the eye. Responses were recorded to full-field stimuli. Correlations between results of both eyes were studied. Results were compared to normative data obtained with corneal electrodes. Results Cone ERG response was obtained in 100/102 eyes. Flicker ERG was obtained in 88/102 eyes. No correlation between eyes was found for the a-wave latency, the a-wave amplitude, and the latency of the flicker. Mean b-wave implicit time of the cone ERG was 38.71±1.6 ms; the median of its amplitude was 10.0 µV. The median of the amplitude of the flicker ERG was 12.55 µV. Conclusions Amplitudes are significantly reduced, with a scaling factor of 8.75 for the b-wave amplitude of the cone ERG compared to corneal electrodes (9.6 for the a-wave amplitude and 8.87 for the flicker amplitude). Our study contributes to the establishment of normative data for skin electrode ERG. It emphasizes the feasibility and accuracy of this method. It is very useful to assess the normality of the ERG in many clinical situations, such as nystagmus and suspicion of delayed visual maturation.

Low versus standard-blood-flow reperfusion strategy in a pig model of refractory cardiac arrest resuscitated with Extra Corporeal Membrane Oxygenation

OBJECTIVE This study was designed to assess the effect of two veno-arterial ExtraCorporeal Membrane Oxygenation (ECMO) blood-flow strategies in an experimental model of Extracorporeal Cardio-Pulmonary Resuscitation (ECPR) on macrocirculatory, metabolic and microcirculatory parameters in the first six hours of ECMO initiation. METHODS Cardiac arrest was induced in 18 pigs by surgical ligature of the left descending coronary artery followed by a low-flow time of 40 min using internal cardiac massage. ECPR was initiated in normothermia with an ECMO blood flow of 30-35 ml.kg-1. min-1 (low-blood-flow group, LBF) or 65-70 ml.kg-1. min-1 (standard-blood-flow group, SBF), with the same mean arterial pressure target of 65 mmHg adjusted with norepinephrine. Macrocirculatory and metabolic parameters were assessed by lactate clearance and carotid blood flow. Microcirculatory parameters were assessed by sublingual microcirculation with Sidestream Dark Field (SDF) imaging and peripheral Near-InfraRed Spectrometry (NIRS). Inflammatory cytokine levels were measured with a multicomplexed ELISA-based array platform. RESULTS There were no between-group differences at baseline and at ECMO initiation (H0). Lactate clearance at H6 was lower in LBF compared to SBF (6.67[-10.43-18.78] vs. 47.41[19.54-70.69] %, p = 0.04). Carotid blood flow was significantly lower (p<0.005) during the last four hours despite similar mean arterial pressure levels. For microvascular parameters, SDF and NIRS parameters were transitorily impaired at H3 in LBF. IL-6 cytokine level was significantly higher in LBF at the end of the experiment. CONCLUSION In an experimental porcine model of refractory cardiac arrest treated by ECMO, a low-blood-flow strategy during the first six hours of resuscitation was associated with lower lactate clearance and lower cerebral blood flow with no benefits on ischemia-reperfusion parameters.

Sequential linear regression with online standardized data

The present study addresses the problem of sequential least square multidimensional linear regression, particularly in the case of a data stream, using a stochastic approximation process. To avoid the phenomenon of numerical explosion which can be encountered and to reduce the computing time in order to take into account a maximum of arriving data, we propose using a process with online standardized data instead of raw data and the use of several observations per step or all observations until the current step. Herein, we define and study the almost sure convergence of three processes with online standardized data: a classical process with a variable step-size and use of a varying number of observations per step, an averaged process with a constant step-size and use of a varying number of observations per step, and a process with a variable or constant step-size and use of all observations until the current step. Their convergence is obtained under more general assumptions than classical ones. These processes are compared to classical processes on 11 datasets for a fixed total number of observations used and thereafter for a fixed processing time. Analyses indicate that the third-defined process typically yields the best results.