Marine Thieux
email: marine.thieux@live.fr

Julien Jung

Romain Bouet

Daniel Gérard

Prisca R Bauer

Olivier Bertrand

Marcela Perrone-Bertolotti

Alexis Arzimanoglou

Philippe Kahane

Jean-Philippe Lachaux

D Gerard

P Kahane F-G

J-P Lachaux

J De Bellescize

V Herbillon

BLAST paradigm: A new test to assess brief attentional fluctuations in children with epilepsy, ADHD, and normally developing children

Keywords: Childhood epilepsy, Attention Deficit Hyperactivity Disorder (ADHD), Attentional stability, Neuropsychological, BLAST

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Attention is a core executive function supported by structural and functional networks which mature throughout childhood and adulthood [START_REF] Rueda | Training, maturation, and genetic influences on the development of executive attention[END_REF][START_REF] Shaw | Attention-deficit/hyperactivity disorder is characterized by a delay in cortical maturation[END_REF]. Substantial deficits in all or some attentional subdomains were shown to significantly impair academic achievement, social and professional integration [START_REF] Barry | Academic underachievement and attentiondeficit/hyperactivity disorder: The negative impact of symptom severity on school performance[END_REF][START_REF] Macallister | Attention and executive functions in children with epilepsy: what, why, and what to do[END_REF][START_REF] Schubert | Attention deficit disorder and epilepsy[END_REF].

Epidemiological studies show that attentional deficits are common in the general population and the most frequent comorbidity in children with epilepsy (CWE) [START_REF] Dunn | Differential diagnosis and treatment of psychiatric disorders in children and adolescents with epilepsy[END_REF]. Attention Deficit Hyperactivity Disorder (ADHD) is the best characterized attentional disorder [START_REF]Diagnostic and statistical manual of mental disorders (DSM-5®)[END_REF]. ADHD occurs in 5 to 7 % of children, more commonly in boys than girls and the mixed subtype (i.e. inattention plus hyperactivity) is overrepresented [START_REF]Diagnostic and statistical manual of mental disorders (DSM-5®)[END_REF]. In children with epilepsy, ADHD is diagnosed in 30 to 40 % of both girls and boys, and the inattentive subtype is more common [START_REF] Macallister | Attention and executive functions in children with epilepsy: what, why, and what to do[END_REF][START_REF] Salpekar | Key issues in addressing the comorbidity of attention deficit hyperactivity disorder and pediatric epilepsy[END_REF][START_REF] Berl | Speed and complexity characterize attention problems in children with localization-related epilepsy[END_REF][START_REF] Williams | Epilepsy and attentiondeficit hyperactivity disorder: links, risks, and challenges[END_REF][START_REF] Brikell | Medication treatment for attention-deficit/hyperactivity disorder and the risk of acute seizures in individuals with epilepsy[END_REF][START_REF] Mercier | Partial validation of a French version of the ADHD-rating scale IV on a French population of children with ADHD and epilepsy. Factorial structure, reliability, and responsiveness[END_REF].

There are qualitative and semi-quantitative Consensus Criteria for diagnosing ADHD, which are regularly updated [START_REF]ADHD: Clinical practice guideline for the diagnosis, evaluation and treatment of Attention-Deficit/Hyperactivity Disorder in children and adolescents[END_REF]. These do, however, not cover all clinically relevant attentional deficits. A significant number of children with attentional complaints does not fulfil the criteria defined by DSM-V [START_REF]Diagnostic and statistical manual of mental disorders (DSM-5®)[END_REF], leading to underdiagnoses [START_REF] Sherman | Parents report more ADHD symptoms than do teachers in children with epilepsy[END_REF][START_REF] Auvin | Systematic review of the screening, diagnosis, and management of ADHD in children with epilepsy. Consensus paper of the Task Force on Comorbidities of the ILAE Pediatric Commission[END_REF].

To improve the detection of those deficits, behavioural performances on neuropsychological tests can be used to confirm clinical suspicion. Some children are suspected to have disturbances in sustained attention, which can be assessed by Continuous Performance Tests (CPT) [START_REF] Semrud-Clikeman | Components of attention in children with complex partial seizures with and without ADHD[END_REF]. There is an ongoing debate about conceptual and methodological approaches to measure "sustained attentional deficits" and their contribution to the ADHD phenotype. Traditional designs are well-adapted to study long lasting and slow drifts away from the ongoing task but brief fluctuations of attention within the task may go unnoticed, especially in tests in which only a subset of the stimuli require attentive processing (e.g. CPT).

Other approaches use the global variability of reaction times (RT) -computed across the entire taskto measure attentional instability for the assessment of ADHD [START_REF] Kofler | Reaction time variability in ADHD: a meta-analytic review of 319 studies[END_REF][START_REF] Gmehlin | Attentional lapses of adults with attention deficit hyperactivity disorder in tasks of sustained attention[END_REF][START_REF] Tamm | Reaction time variability in ADHD: a review[END_REF], in addition to more standard measures such as average RT and error rate. None of these measures alone, however, captures the fact that when individuals are more focused, they tend to react faster, with less errors and with more stable performance.

Ideally, indices revealing attentional deficits should take all these elements into account. We suggest two measures with such properties, adapted from a task designed specifically to detect brief attentional fluctuations.

Given that in children with epilepsy (CWE), attentional deficits seem characterized by slow and fluctuating responses [START_REF] Williams | Epilepsy and attentiondeficit hyperactivity disorder: links, risks, and challenges[END_REF][START_REF] Auvin | Systematic review of the screening, diagnosis, and management of ADHD in children with epilepsy. Consensus paper of the Task Force on Comorbidities of the ILAE Pediatric Commission[END_REF] and a significant number of children with attentional problems remain underdiagnosed [START_REF] Ekinci | Attention-deficit hyperactivity disorder (ADHD) in epilepsy and primary ADHD: Differences in symptom dimensions and quality of life[END_REF], the International League Against Epilepsy (ILAE) and the American Academy of Paediatrics (AAP) advocate the urgent need for developing more objective and reliable clinical tools, taking into account the broad spectrum of attentional deficits [START_REF]Diagnostic and statistical manual of mental disorders (DSM-5®)[END_REF][START_REF] Auvin | Systematic review of the screening, diagnosis, and management of ADHD in children with epilepsy. Consensus paper of the Task Force on Comorbidities of the ILAE Pediatric Commission[END_REF].

The main objective of this study was to assess attentional stability in CWE with or without comorbid ADHD, ADHD only and normally developing children. We used the recently developed BLAST (Bron Lyon Attention Stability Test [START_REF] Petton | BLAST: a short computerized test to measure the ability to stay on task. Normative behavioral data and detailed cortical dynamics[END_REF]) to assess the ability to "stay on task" on a second-to-second basis. This ability requires continuous and undivided attention, reflecting the duration of many task-units in daily life (such as listening to an explanation integrally, reading one or two pages of a book or remaining focused on the resolution of an arithmetical school task).

We aimed to assess the specific BLAST variables reflecting the dynamic aspects of responses as accuracy, regularity and speed. They rely on reproducing series of fast and error-free responses and regular and error-free series and might be disturbed by brief attentional fluctuations.

Further objectives were to identify the most discriminating BLAST variables within the subgroups and to investigate factors related to epilepsy (i.e. seizure type and frequency, pharmacotherapy, age of onset, epilepsy duration) in order to better characterize the attentional components that are disturbed in children with attentional deficits.

We hypothesize that children with attentional deficits (i.e. children with epilepsy and ADHD and children with ADHD without epilepsy) show reduced attentional stability compared to healthy controls. We expect that the specific BLAST variables, Intensity and Stability, are more appropriate to detect these subtle attentional deficits than the measures commonly used, like RT and error, allowing for better clinical management.

Materials and methods

Participants

We included four groups of children: 141 children with epilepsy (80 with comorbid ADHD and 61 without comorbid ADHD), 52 children with ADHD without epilepsy and 60 children with a normal development. For all groups, inclusion criteria were: For all children, ADHD rating scale (ADHD-RS) scores and information on socio-professional status of parents [START_REF]Nomenclatures des Professions et Cate ́gories Socioprofessionnelles (PCS)[END_REF] were collected.

Procedure

Task

For children with epilepsy and /or ADHD, the experiment was done during regular clinical followup requiring a video-electroencephalogram (EEG). An EEG was also performed in healthy children for a separate study. For healthy controls, the task was conducted at the Lyon Neuroscience Research Center (CRNL). The paradigm was adapted for children from the original BLAST [START_REF] Petton | BLAST: a short computerized test to measure the ability to stay on task. Normative behavioral data and detailed cortical dynamics[END_REF].

Participants were seated in front of a computer screen, in a quiet room with minimal distraction. They were informed that they were going to play a game, with the aim to find a balance between speed and accuracy. The experiment started after a 1-minute training period: there were three blocks of 3 minutes interspersed by a 30 seconds (s) break. The complete experiment took approximately 15 minutes. Visual BLAST stimuli were presented on a PC running the Presentation Ⓡ stimulus delivery software [25] synchronized with the EEG acquisition system. For each trial, the stimulus appeared in foveal vision, in black on a grey background.

Participants were instructed to find a target letter coloured in red in an array of four letters. First, the target letter appeared on the screen during 200 milliseconds (ms), followed by a mask (#) during 300 ms, followed by a 2-by-2 array of four letters in which one of them was red in 50% of cases (Figure 1). They had to provide their responses manually using a joystick. The "Yes" responses were provided when one of the four letters was red using their non-dominant hand. The "No" responses were provided when no red letter was presented and using their dominant hand. The first letter was always the same as the red target letter. We decided to maintain this design in the simplified version as a signal to focus on the task. The next trial started 800 ms after the array if a response was given and 3800 ms after the array in case of no-response. No feedback was given after trials. This paradigm involved visual target detection, selection of response and motor transformation, all dependent on attentional resources of the participant. Visual search is automatized by the saliency of the stimulus, producing a "pop-out" effect. The BLAST has good psychometric properties [START_REF] Petton | BLAST: a short computerized test to measure the ability to stay on task. Normative behavioral data and detailed cortical dynamics[END_REF] : i) a good test-retest reliability ( r > 0.6 for most measures); ii) a significant correlation between the subtest of processing speed index (e.g. CODE) from the Wechsler Intelligence Scale for children (WISC-IV) and the Wechsler Adult Intelligence Scale (WAIS-IV) [START_REF] Wechsler | Wechsler intelligence scale for children-Fourth Edition (WISC-IV)[END_REF][START_REF] Wechsler | Wechsler adult intelligence scale-Fourth Edition (WAIS-IV)[END_REF] and most behavioural indices of the BLAST; iii) a high sensitivity to the Inattention component of the ADHD-RS (and more precisely with the observed inability to stay-on-task) for all the indices.

Behavioural measures

Three standard measures were assessed: reaction time (RT), error rate and variability of RT.

The RT is the time (in ms) between the onset of the letter array and the motor response. The Error is the percentage of no-response and false alarms. The Variability is the variance of the RT, computed over all trials.

Two specific variables were computed: Stability and Intensity. These indices reveal momentary lapses of attention to capture the moment-to-moment dynamics of attention.

Intensity was derived from the assumption that highly focused individuals tend to respond fast and with few errors. It quantifies the ability of individuals to produce long series of fast and accurate responses, and ranges from 0 and 100 (maximal performance). The computation of Intensity is fully described in supplementary material.

Stability was derived from the assumption that task-irrelevant cognitive processes add "noise" to the RT [START_REF] Gmehlin | Attentional lapses of adults with attention deficit hyperactivity disorder in tasks of sustained attention[END_REF]. It quantifies the ability of an individual to produce long series of correct responses with a stable RT, independently of its speed, and ranges from 0 and 40 (maximal performance). The Stability measure relies on the variation of reaction times without taking speed into account, focusing on regularity. The full details of Stability computation are provided in the supplementary materials.

Statistical analysis

Statistical analyses were conducted using the R software [START_REF] Rdevelopment | TEAM 2009: R: A language and environment for statistical computing[END_REF].

Demographic analysis

ANOVA and Chi2 tests were performed in order to compare socio-professional status of parents and age between the four groups and epilepsy type and duration, seizure frequency and number of anti-seizure drugs between children with epilepsy with and without comorbid ADHD. Statistical significance value was set to a p-value below 0.05 for each test.

Behavioural analysis

First, an ANOVA was conducted with a single explanatory factor (block factor) to assess the influence of the order of each block on BLAST measures (to rule out a potential influence of fatigue). Since no effect of the block factor was shown, we used trials from the three blocks for subsequent statistical analyses.

To assess the factors influencing the attentional performance during BLAST paradigm, we used an ANOVA applied on a linear mixed effect model (R-lme4 package) [START_REF] Bates | lme4: Linear mixed-effects models using Eigen and S4[END_REF] taking into account the heterogeneity, heteroscedasticity and non-normality of data. These models were used because they take intersubject and inter-age heterogeneity into account. The choice of the best model was made according to criteria reflecting its parsimony (AIC and BIC values). Type II variance analyses (car package version 3.0-2) [START_REF] Fox | Multivariate linear models in R. An R Companion to Applied Regression[END_REF] were performed using a Wald Chi2 test. Post-hoc tests, adjusted for the number of comparisons, were performed using the Lsmeans package (Lsmean version 2.27-61) [START_REF] Sánchez-Carpintero | Attentional ability in children with epilepsy[END_REF] with the Tukey method. Two analyses were performed:

(a) the first analysis included the four groups (epilepsy with ADHD and without ADHD, ADHD and controls) considering the group and the age as explanatory variable.

(b) the second analysis focused on the epilepsy groups by taking the age of seizure onset, the seizure frequency during the last 12 months (none, 1-5 seizures, 5-12 seizures, 13-50 seizures, 1 seizure per week or one seizure per day), the type of epilepsy (focal or generalized), the duration of epilepsy (duration in months between the age of the first seizure and the age at the test) and the number of anti-seizure drugs (none, monotherapy or polytherapy) as explanatory variables.

For each analysis, variables to be explained were RT, error rate, variability, Stability and Intensity.

A complementary analysis was performed to describe behavioural responses of children with epilepsy with attentional complaints but who did not fully meet the DSM-V criteria (i.e. 4 to 5 inattention criteria and less than 6 hyperactivity criteria) (n = 17). To this end, we established age-dependant normative values for the different BLAST scores in the control group using the R-lme4 package [START_REF] Bates | lme4: Linear mixed-effects models using Eigen and S4[END_REF]. A polynomial fit was used to model the relationship between BLAST variables and age of the subject with a 95% confidence interval. A cut-off was established (95% confidence interval) and allowed to categorize the performance for each BLAST variable as pathological or not pathological as compared to the norm derived from the control group. The performance was considered as "pathological" when its attentional performance was out of the confidence interval of normative values established on control children.

Results

Six CWE with ADHD and 3 without ADHD who experienced a seizure during the EEG-BLAST session, 9 who were treated with methylphenidate (i.e. 7 children with epilepsy and ADHD and 2 children with epilepsy only) and 7 healthy subjects with practical problems during the experiment were excluded from the analysis. One CWE with a mean reaction time lower than 200ms and error percentage higher than 40% was excluded from statistical analysis because of its outlier performances. After exclusion, the epilepsy group included 122 children (67 with ADHD and 55 without ADHD), the ADHD group included 52 children and 53 healthy children formed the control group. Additional information about subjects are given in Table 1.

Attentional performances

First, we performed an ANOVA on the "block" factor for each score of the BLAST, to check for a possible learning and/or fatigue effects during the experiment. This analysis showed no significant effect (F (2, 672) < 2, p > .05). Type II variance analyses performed with Wald's Chi 2 showed that there was no significant difference between the groups for the RT (Figure 2 2.

Regardless of the

There was no significant interaction between age and groups: thus, difference between groups appear independently of the age effect.

Relationship between characteristics of epilepsy and attentional performances

In CWE (with and without ADHD), earlier age of the seizure onset was associated with a higher RT

Relationships between attentional performances on BLAST and ADHD criteria

There were 17 CWE without ADHD who did not fully meet DSM-V criteria for ADHD and who did not have pathological scores on the ADHD-RS. The BLAST highlighted difficulties in attentional stability in six of those children using the RT, in eight using error rates, in 16 using Stability and in 13 using Intensity (see table 3).

Discussion

The recently described BLAST paradigm evaluates the ability to stay on-task by assessing the dynamics of brief attentional fluctuations. Our study aimed at evaluating the clinical utility of a simplified BLAST version in children with high prevalence of attentional deficits: children with ADHD and children with a broad range of epileptic disorders. Few studies have been performed to better characterize the nature of attentional complaints in those populations and focused mostly on sustained attention [START_REF] Sánchez-Carpintero | Attentional ability in children with epilepsy[END_REF]. To the best of our knowledge, none specifically measured the influence of very brief attentional fluctuations on attentional stability.

We compared the impact of intra-task attentional fluctuations on attentional stability between CWE with and without comorbid ADHD, children with ADHD without epilepsy and in typical developing children. We found that CWE and/or ADHD performed worse on the BLAST than healthy controls. Two new specific measures, Stability and Intensity, showed deficits in attentional functioning that are not captured by classical variables such as reaction time, error rate or the global variability of reaction time across trials.

In line with our hypothesis, Stability differentiated controls from the three disease groups (ADHD, CWE with and without ADHD). Intensity distinguished the children with an ADHD component (i.e. CWE with ADHD or children with ADHD only) from controls.

These results indicate that standard measures such as reaction times, error rates or variability alone are insufficient to detect fluctuations in attentional stability, which is an essential component of cognitive functioning in everyday life. Traditional attention tests (e.g. CPT) that assess performance over the entire test do not capture intra-task dynamics, which can lead to an incomplete assessment of attentional deficits. These very brief attentional fluctuations can be explained by momentary lapses of attention (MLA) lasting a few moments (seconds or less) during which cognitive resources are side-tracked towards processes unrelated to the task [START_REF] Weissman | The neural bases of momentary lapses in attention[END_REF]. Previous studies suggested that MLA manifest by isolated errors or a transient increase in RT [START_REF] Dunn | ADHD and epilepsy in childhood[END_REF][START_REF] Lin | Uncovering the neurobehavioural comorbidities of epilepsy over the lifespan[END_REF]. With its high temporal resolution and its new specific variables, the BLAST captures the dynamics of attentional performances throughout the task and allows to compare the fluctuations of speed and quality of response underlying attentional stability.

The Stability measure relies on the variation of reaction times without taking speed into account, focusing on regularity. It differentiated controls from the three disease groups and interestingly revealed lower performances in CWE without ADHD, despite normal speed. This result show that slowness, which is frequently reported in previous studies, does not fully describe attentional disorders in those children [START_REF] Srnka | Intraindividual variability in attentional vigilance in children with epilepsy[END_REF]. In children who do not fully meet criteria of ADHD, but have problems at school or reported by parents, difficulties in attentional stability can be more easily identified by the BLAST than by conventional measures. We found that especially Stability was sensitive to attentional deficits that were not detected by the ADHD-RS. This new test may thus increase the diagnostic sensitivity for attentional disorders, as recommended by the ILAE and the AAP.

The Intensity measure of the BLAST distinguished children with an ADHD component (i.e. CWE with ADHD or children with ADHD only) from controls. This specific measure, which integrates processing speed and accuracy of the responses, seems to best reflect the core behavioural attentional disorders, shared by ADHD and CWE with ADHD.

As a whole, our results suggest that the BLAST highlights attentional difficulties that are not measured by conventional scales. Thus, BLAST can complement the assessment of attentional deficits to provide a better diagnosis of attentional disorders. The new specific measures, Stability and Intensity, may also be computed for other neuropsychological tests that measure reaction time and errors, such as the kiTAP battery [START_REF] Zimmermann | kiTAP. Test d'évaluation de l'attention[END_REF].

In CWE (with and without ADHD), we found that an earlier seizure onset was associated with lower performances on RT, error percentage, Stability and Intensity. As expected, the number of anti-seizure drugs also impacted performances [START_REF] Kerr | International consensus clinical practice statements for the treatment of neuropsychiatric conditions associated with epilepsy[END_REF][START_REF] Meador | Cognitive outcomes and predictive factors in epilepsy[END_REF]. CWE with polytherapy had higher RT and error percentages and tended to have lower Stability and Intensity than CWE with monotherapy or without treatment. Stability and Intensity were thus less impacted by the number of anti-seizure drugs than classical measures.

In line with earlier results showing that fluctuations in attention were associated with an earlier age at diagnosis [START_REF] Berl | Speed and complexity characterize attention problems in children with localization-related epilepsy[END_REF][START_REF] Williams | Epilepsy and attentiondeficit hyperactivity disorder: links, risks, and challenges[END_REF][START_REF] Lin | Uncovering the neurobehavioural comorbidities of epilepsy over the lifespan[END_REF], our results show that the age of the first seizure had an impact on attentional stability, independent from the duration of epilepsy. In addition, attentional deficits were not linked to epilepsy-related clinical characteristics such as seizure frequency or epilepsy type. These results suggest that early seizure onset impacts attentional skill development at crucial developmental milestones in childhood. On the contrary, it appears that the diagnosis of focal versus generalized epilepsy was not a major determinant of attentional deficits, within the limits of our relatively small cohort of patients regarding epilepsy types.

The capacity to maintain attention focused matures in childhood [START_REF] Ruff | Development of sustained, focused attention in young children during free play[END_REF][START_REF] Richards | Attention in young infants: A developmental psychophysiological perspective[END_REF]. The neuroanatomical network involved in the BLAST was recently described [START_REF] Petton | BLAST: a short computerized test to measure the ability to stay on task. Normative behavioral data and detailed cortical dynamics[END_REF]. It involves the Dorsal Attentional Network (DAN) [START_REF] Corbetta | Control of goal-directed and stimulus-driven attention in the brain[END_REF], a network at the interface of the pre-motor areas and the anterior cingulate gyrus involved in maintaining attention throughout time. This activation pattern was also associated with a deactivation of the Default Mode Network (DMN), in line with previous studies showing deactivation of the DMN in active tasks [START_REF] Raichle | A default mode of brain function[END_REF]. Studies using intracranial EEG, however, show a brief reactivation of this network between each trial [START_REF] Petton | BLAST: a short computerized test to measure the ability to stay on task. Normative behavioral data and detailed cortical dynamics[END_REF]. Good BLAST performance seems to depend on the interplay between the DAN and the DMN. We suggest that children with reduced attentional stability may have an imbalance between these two networks, resulting in the intermittent reactivation of the DMN or limited activation of the DAN.

Limitations of our study include the recruitment of CWE from a tertiary epilepsy centre, potentially leading to a high prevalence of comorbid disorders such as cognitive difficulties and a high heterogeneity of the population. Moreover, CWE and/or ADHD were investigated at different stages of the disease in a crosssectional design. More large-scale studies are thus needed to evaluate attentional performance in different epilepsy syndromes and longitudinal studies may be performed to evaluate the influence of epilepsy duration.

In CWE, we excluded the impact of potential seizures on task results, but interictal epileptiform discharges were not considered. This will be the aim of future studies.

Conclusion

Attentional deficits are a major concern in CWE and / or ADHD. Using a novel test, we demonstrate that attentional stability is altered by brief attentional fluctuations in CWE with or without ADHD and in children with ADHD only, compared to controls.

The BLAST improved the detection of deficits in attentional stability in children with epilepsy and attentional complaints, who did not meet all criteria for ADHD. The BLAST identified differences in attentional functioning in children with ADHD, with or without epilepsy compared to controls. This test could also show the cognitive impact of a polytherapy with anti-seizure drugs.

The BLAST with its innovative specific attentional indices should be included in neuropsychological assessments of attentional disorders, particularly in syndromes with a high prevalence of pure attentional deficits. This ergonomic test lasts 15 minutes and can be easily performed in the setting of standard followup. It is well adapted to children and may thus be evaluated in a broad range of neurodevelopmental disorders impacting cognitive skills. and S(T') respectively (bottom and top right panels, respectively), from the ratio of the area under the curve (red) divided by the total area of the square englobing that curve (white). The bottom left graph illustrates the calculation of P(T) from the reaction times for an example value of T (600 ms : 9 points) (« instantaneous » standard deviations of reaction times -computed over three consecutive trials, are shown as gray vertical bars). The procedure is repeated for all T between 300 ms and 1500 ms to generate red plot P(T). The top left graph illustrates the calculation of S(T') from the « instantaneous » standard deviation s(trial) of the normalized reaction times (r'(trial)) for an example value of T' (20 : 12 points). The normalized reaction times r'(trial) are simply reaction times expressed as % of the median reaction time. S is depicted in the top left graph as vertical bars (green = s less than 10; yellow = s less than 20; red otherwise, note that s is set to 40 for every error) and red vertical bars in the upper left graph). The procedure is repeated for all T' between 0 and 40 to generate red plot S(T') on the right.

"One limitation of Intensity is that it is mathematically lower for participants with slower reaction times (typically, elderly people). Yet, it is clear that someone with slow but close to constant reaction times, and no errors, is fully « on-task ». Therefore, Intensity should be complemented with another measure which emphasizes stability more than speed: this is Stability (see figure above). Stability was derived from the assumption that task-irrelevant cognitive processes add "noise" to reaction times [START_REF] Gmehlin | Attentional lapses of adults with attention deficit hyperactivity disorder in tasks of sustained attention[END_REF]: it was thus computed from the "instantaneous" stability of reaction times r(trial i). And since our intention was to minimize the effect of the overall speed, we considered the stability of "normalized reaction times"; i.e. reaction times expressed in % of the median reaction time for the entire task: r'(trial i) = 100*r(trial i)/median(r(all trials)).

We defined the instantaneous stability of attention for trial i as instab(trial i) = std(r'(trial i-1):r'(trial i+1)), it is computed over sliding windows of three consecutive trials for maximal temporal precision. Stability was computed from instab(trial i) following a procedure similar to the computation of Intensity from r(trial i). To penalize errors as in Intensity, instab was set to a maximal value [START_REF] Ruff | Development of sustained, focused attention in young children during free play[END_REF] for unsuccessful trials. As with Intensity, we devised a scoring system S(T') which accumulates N-5 points for each series of N>4 winning trials for which instab stays below T' (a procedure repeated for T' values between 0 and a maximum of 40).

Graphically, instab measures the width of the « tube » in which the reaction time plot seems to be confined locally (i.e. for three consecutive trials) (see figure above), and S(T') integrates the length of such series, excluding series shorter than 5 for the same reason as in Intensity. In short, Stability evaluates the ability to generate long and narrow "tubes" of reaction times: Stability = 100xAUC(S)/max(AUC), where AUC is the area under the curve S(T') and max (AUC) its maximal theoretical value."

  (a) age between 6 to 18 years old; (b) ordinary school curriculum; (c) no major visual or auditory impairment; (d) no motor disability of the upper limbs; (e) no epileptic seizure during the task. All children and both parents or caretakers signed an informed consent before participating. The study protocol was approved by the ethics committee Sud-Est III (Lyon B) n°2016-013B for healthy children and by the ethics committee Sud-Est V (COGNI-AIC-38RC14.374) for CWE and/or ADHD. This study has been approved by the CNIL (HCL CNIL register n ° 18-315) and by the ethics committee of Hospices Civils de Lyon (HCL) (n ° 19-19). Children with Epilepsy (CWE) were recruited from the department of Paediatric Clinical Epileptology of the Femme-Mere-Enfant hospital (HFME), HCL, Lyon, France between 2015 and 2017. All CWE were included in this cross-sectional study of attentional disorders regardless of the evolution of their epilepsy, their epilepsy syndrome, type of epilepsy (i.e. focal or generalized, aetiology), seizure frequency or number of anti-seizure drugs. The diagnosis and type of epilepsy were confirmed by two experienced Neurologists according to ILAE criteria [22-23]. Children with ADHD were recruited from the department of Child and adolescent psychopathology unit of the same hospital between 2015 and 2017. The diagnosis of ADHD (also in children with epilepsy) was confirmed by an experienced neuropsychiatrist and a neuropsychologist from the HFME using the ADHD-RS and the clinical questionnaire for ADHD from the DSM-V. None of the children was treated with a psychostimulant. Healthy children without a history of seizures or clinical diagnosis of neurodevelopmental disorders were recruited between 2016 and 2017 through adverts in local newspapers and schools.

Figure 1 .

 1 Figure 1. Typical trial of the BLAST experimental paradigm

  -a), the error percentage (Figure2-b) and the variability (Figure2-e).There were significant differences between groups for the Stability (Wald χ 2 (3, 45906) = 28.369, p < .0001) (Figure2-c) and Intensity (Wald χ 2 (3, 45906) = 9.084, p < .05) (Figure2-d). Post-hoc analyses showed that CWE with and without ADHD and children with ADHD performed worse than the control group. Controls had a higher Stability than CWE with ADHD (t (220) = 4.383, p < .0001) and than children with ADHD (t (219) = 4.806, p < .0001) (Figure2-c). The control group also had a higher Intensity than CWE with ADHD (t (218) = 2.738, p < .05) (Figure2-d). Mean scores for each group are shown in Table

Figure 2 .

 2 Figure 2. Each point represents the median reaction time (a), the error rate (b), the Stability (c), the Intensity (d) and the variability (e) for each subject according to the groups (red: epilepsy with ADHD, green: epilepsy without ADHD, blue : ADHD, purple : control). The central line of the boxplot corresponds to the median of each score, the upper and lower parts corresponds to the first and third quartiles. Difference between groups are represented by star: ***: p < .001; *: p < .05; . : p < .1

(Wald χ 2 ( 1 ,

 21 23453) = 22.399, p < .0001) (Figure 3-a), a higher error percentage (Wald χ 2 (1, 23453) = 5.269, p < .05) (Figure 3-d) and lower Stability (Wald χ 2 (1, 23453) = 9.469, p < .01) (Figure 3-c) and Intensity (Wald χ 2 (1, 23453) = 9.904, p < .01) (Figure 3-b).In these children, a higher number of anti-seizure drugs, was correlated with lower performances. It was significant for the RT (Wald χ 2 (2, 23453) = 11.727, p <.001) and the error rate (Wald χ 2 (2, 23453) = 7.394, p < .01) and not significant for Stability and Intensity (p > .05). Post-hoc analyses demonstrated that children with polytherapy had a higher RT (t (81) = 2.979, p < .05) and error percentage (t (94) = 2.712, p < .05) than children with monotherapy. There was no significant difference in performances between children without anti-seizure drugs and children with monotherapy (p > .05).Neither epilepsy type, groups (with and without ADHD), seizure frequency nor epilepsy duration were related to the BLAST outcome measures (RT, error percentage, Intensity and Stability) (p > .05).

Figure 3 .

 3 Figure 3. Each point represents the median reaction time (a), Intensity (b), Stability (c) and rate of error (d) for each subject according to the age of the first seizure (in months).

Figure :

 : Figure :Scoring systems for Intensity and Stability. Intensity and Stability are computed from graphs P(T) and S(T') respectively (bottom and top right panels, respectively), from the ratio of the area under the curve (red) divided by the total area of the square englobing that curve (white). The bottom left graph illustrates the calculation of P(T) from the reaction times for an example value of T (600 ms : 9 points) (« instantaneous » standard deviations of reaction times -computed over three consecutive trials, are shown as gray vertical bars). The procedure is repeated for all T between 300 ms and 1500 ms to generate red plot P(T). The top left graph illustrates the calculation of S(T') from the « instantaneous » standard deviation s(trial) of the normalized reaction times (r'(trial)) for an example value of T' (20 : 12 points). The normalized reaction times r'(trial) are simply reaction times expressed as % of the median reaction time. S is depicted in the top left graph as vertical bars (green = s less than 10; yellow = s less than 20; red otherwise, note that s is set to 40 for every error) and red vertical bars in the upper left graph). The procedure is repeated for all T' between 0 and 40 to generate red plot S(T') on the right.

Table 1 .

 1 Demographic and clinical characteristics of the study sample

	Epilepsy	Epilepsy
	with	without	ADHD	Control
	ADHD	ADHD

The four groups were not different in terms of age (F (3, 223) = 1.691, p > .05) and socioprofessional status of parents (χ 2 (15) = 13.398, p >.05).

The two groups of CWE were not different in terms of duration of epilepsy (F (1, 120) = 1.049, p> .05), type of epilepsy (χ 2 (1) = 0.915, p > .05), seizure frequency (χ 2 (5) = 3.219, p > .05), number of antiseizure drugs (χ 2 (2) = 0.276, p > .05) and the age of first seizure (F (1, 120) = 3.719, p > .05).

Table 2 .

 2 Mean scores on BLAST test for each group

		Epilepsy with ADHD	Epilepsy without ADHD	ADHD	Control
	N	67	55	52	53
	BLAST -mean (SD)
	Reaction time (seconds)	0.75 (0.26)	0.71 (0.28)	0.65 (0.19)	0.63 (0.18)
	Error rate (percentage)	7 (7)	6 (7)	6 (6)	4 (4)
	Variability	0.31 (0.4)	0.21 (0.35)	0.15 (0.22)	0.13 (0.23)
	Stability	23 (14)	28 (16)	24 (13)	36 (15)
	Intensity	54 (20)	58 (21)	58 (18)	66 (17)

Table 3 .

 3 BLAST performance scores in children with epilepsy

				BLAST
	Reaction time	Rate of errors	Stability		Intensity
	Deficit Normal	Deficit Normal	Deficit Normal	Deficit Normal
	6	11	8	9	16	1	13	4

Acknowledgements

We thank all children and their parents for their participation in the study and gratefully acknowledge the medical staff and fellows involved in this project for their help in recruiting participants : Dr. P. Keo-Kosal, Dr. K. Ostrowsky-Coste, Dr. E. Panagiotakaki, Dr. A. Montavont, Dr. J. Toulouse, Dr. C. Milleret, Dr. Z. Gokce, Mrs. F. Ilsky-Lecoanet, Mrs. A. Marcastel.

This study was conducted without a specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Supplementary Material

Description of outcomes measures [START_REF] Petton | BLAST: a short computerized test to measure the ability to stay on task. Normative behavioral data and detailed cortical dynamics[END_REF] :

" Intensity (see figure below), derives from the natural assumption that highly focused individuals tend to respond fast and with few errors. In other words, a performance graph showing reaction times (y-axis) for all the trials (x-axis) should display long series of hits below a given time limit T (horizontal line), even when T is low. If we cumulate the length of all successful series below T (i.e. with a reaction time consistently faster than T), we reach a measure P(T) which should be high for "highly-focused" individuals even when T is small (i.e., 500 ms). To penalize errors and to be consistent with the adaptive designs which required participants to generate successful series of five trials, we computed a measure P(T), which included only series longer than five consecutive wins, cumulating N-5 « points » for every such series (where N is the length of that series). P(T) is the number of points for time limit T; it is computed for every value of T between 300 ms and 1500 ms (no one could generate series of hits faster than 300 ms). That scoring system penalized errors, as any error interrupted the ongoing series and the participant had to succeed at least five new times before her score increased again. Graph P(T), which increases with longer T, immediately distinguishes visually between several types of participants/strategies : fast reaction times with many errors ('globally impulsive participants'), slow reaction times with few errors ('globally meticulous'), slow reaction times with many errors ('slow inattentive' type) and fast reaction times with few errors ('fast and focused').

Fast and focused participants are characterized by a large area under the curve P(T): for that reason, we defined a behavioral indice of attention, Intensity = 100xAUC(P)/max(AUC), where AUC is the area under the curve P(T) and max(AUC) its maximal theoretical value. Intensity refers to, and is high for, the "fast and focused» type. One might object that lower values of Intensity might not disambiguate the 'impulsive' and the 'meticulous' types, but those two profiles can be differentiated by considering also the median of their reaction times (and graph P(T))."


Aurélie Lagrange

Damien Decoux

Nathalie Briot

Audrey Hennequin

Bruno Coudert

Isabelle Desmoulins

Dr Aurélie Bertaut
email: abertaut@cgfl.fr.

Visceral osteopathic manipulative treatment reduces patient reported digestive toxicities induced by adjuvant chemotherapy in breast cancer: A randomized controlled clinical study

Keywords: NCT02840890 breast cancer, adjuvant chemotherapy, nausea and vomiting, constipation, osteopathy, quality of life

de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

INTRODUCTION

Breast cancer is the most common cancer in women in the world. In France, over 56 000 new cases were estimated in 2018 [START_REF] Bray | Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries[END_REF]. Despite the increasing number of tumours discovered at a localized stage, the majority of patients benefit from adjuvant chemotherapy whose current standard is 3 cycles of FEC 100 (fluoracil, epirubicin, cyclophosphamide) and 3 cycles of docetaxel [START_REF] Bonneterre | Long-Term Cardiac Follow-Up in Relapse-Free Patients After Six Courses of Fluorouracil, Epirubicin, and Cyclophosphamide, With Either 50 or 100 mg of Epirubicin, As Adjuvant Therapy for Node-Positive Breast Cancer: French Adjuvant Study Group[END_REF][START_REF]Avis TAXOTERE (docétaxel). HAS-Direction de l'Evaluation Médicale[END_REF][START_REF] Adjuvant | Benefit of a high-dose epirubicin regimen in adjuvant chemotherapy for node-positive breast cancer patients with poor prognostic factors: 5year follow-up results of French Adjuvant Study Group 05 randomized trial[END_REF]. The effectiveness of this protocol is accompanied by disabling adverse effects, namely nausea and vomiting [START_REF] Roché | Sequential Adjuvant Epirubicin-Based and Docetaxel Chemotherapy for Node-Positive Breast Cancer Patients: The FNCLCC PACS 01 Trial[END_REF]. Current guidelines on treatments to prevent these gastrointestinal toxicities include an association of neurokinin (NK)1 receptor antagonists (e.g Aprepitant) from day 1 to day 3, to serotonin (5-HT)3 receptor antagonists (Setron) on day 1 and corticosteroid therapy from day 1 to day 3 [START_REF]Comission de la transparence. Avis aprépitant[END_REF][START_REF] Roila | MASCC and ESMO guideline update for the prevention of chemotherapy-and radiotherapyinduced nausea and vomiting and of nausea and vomiting in advanced cancer patients[END_REF].

Pilot studies suggested that massage reduces nausea in women with breast cancer undergoing chemotherapy [START_REF] Dibble | Acupressure for nausea: results of a pilot study[END_REF][START_REF] Billhult | Massage relieves nausea in women with breast cancer who are undergoing chemotherapy[END_REF]. A RCT with a cross-over design assessed the impact of an osteopathic treatment on the QoL of in 40 cancer patients undergoing chemotherapy. Breast cancer patients represented 33% of the study population. A significant reduction of nausea and vomiting, pain and insomnia were found. Improvement of constipation was noted [START_REF] Favier | Évaluation de l'efficacité d'un traitement ostéopathique sur les effets secondaires et la qualité de vie de patients sous chimiothérapie Essai clinique multicentrique randomisé[END_REF].

Although these results are encouraging, different patients were submitted to different osteopathic techniques depending on patient's motility dysfunctions. Moreover, patient's chemotherapy and anti-emetic regimen were not standardized.

The aim of this randomized controlled clinical study was to determine the impact of visceral osteopathy manipulation (VOM) on the incidence of nausea and vomiting occurring during the first 3 cycles of chemotherapy 3 FEC100/Docetaxel in women operated for breast cancer and undergoing adjuvant chemotherapy in Centre Georges-François Leclerc, CGFL. The impact of visceral osteopathy on the incidence of constipation and overall QoL was also studied.

METHODS

Study design

Single-centre, randomized, double-blind, parallel, controlled clinical study with allocation of participants into the experimental group, undergoing visceral osteopathic technique or placebo group, subjected to a superficial manipulation. Study protocol was approved by an ethics committee and registered in Clinical tial.gov (NCT02840890) PREDIGOSTEO.

Population

Ninety-four women older than 18 years operated for a breast cancer stage 1 to 3, in complete resection and to whom a 3 FEC 100 chemotherapy (5-fluorouracil 500 mg/m2, epirubicin 100 mg/m2, cyclophosphamide 500 mg/m2, given intravenously) has been prescribed. Study main exclusion criteria were metastatic breast cancer, operated breast cancer with incomplete resection, known digestive disorders/diseases and inability to receive any of the elements of the antiemetic treatment. Detailed description of all inclusion and exclusion criteria is provided in Supplementary Table 1.

Antiemetic regimen

All patients were treated with an antiemetic prophylactic regimen that consisted of aprepitant 125, 80, 80 at D1, D2, D3, intravenous ondasetron 8 mg at D1, intravenous methylprednisolone 80 mg at D1, 3 pills per day of metoclopramide 10 mg from D1 to D3 and 1 morning and 1 evening pill of alprazolam 0.25 mg from D1 to D3.

Osteopathic Manipulative treatment

After each of the 3 initial cycles of FEC 100-Taxotere chemotherapy, each patient was seen by the osteopath for a 15 minutes session. All osteopathic sessions were held in a dedicated room. All patients were managed by a single board-certified osteopath.

In treatment group, patients received a visceral manipulation consisting of chest wall and diaphragm muscle relaxation through manual thoracic compression [START_REF] Jarry | Ostéopathie et effets secondaires digestifs de la chimiothérapie[END_REF]. In control group, patients received a superficial/soft tissue manipulation without action on deeper chest wall and abdominal structures. Of note, compression intensity was reduced in this group to avoid any manipulation of diaphragm and intercostal muscles.

QoL

Health related QoL was assessed using the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 [START_REF] Aaronson | The European Organization for Research and Treatment of Cancer QLQ-C30: a quality-of-life instrument for use in international clinical trials in oncology[END_REF]. Assessment was performed after each of the 3 cycles of FEC 100-Taxotere chemotherapy, after each active or placebo manipulation.

Sample size calculation

The expected rate of patients suffering from at least one episode of nausea and/or vomiting during the first 3 cycles of FEC 100-Taxotere chemotherapy was 65% in placebo and 35% in experimental group. Accordingly, 86 patients would be sufficient to demonstrate a difference between groups, with a type I error α of 5% and a power of 80%. By taking into account a 10% rate of patients lost to follow-up, a sample of 94 patients would be sufficient to demonstrate a difference between groups, therefore 47 patients should be included per arm.

Study description

A 1: 1 ratio simple randomization technique (Tenalea software) was used.

The main objective was to evaluate the impact of VOM on the incidence of nausea and vomiting occurring during the first 3 cycles of FEC 100 during chemotherapy with 3 FEC100/Docetaxel in women with operated breast cancer and adjuvant treatment. The primary endpoint was rate of patients reporting at least one episode of nausea and/or one or more vomiting episodes of grade 1 or higher on any of the first 3 cycles.

The secondary objectives of the study were to evaluate the impact of VOM on the incidence of constipation during the first 3 cycles of FEC 100 during chemotherapy and to evaluate the impact of VOM on overall QoL for the first 3 cycles. The secondary endpoints were the rate of patients reporting at least one episode of constipation of grade greater than or equal to 1 on one of the first 3 cycles and the QLQ-C30 questionnaire. Nausea and/or vomiting and constipation rates were calculated based on the clinician reported side-effects using the Common Terminology Criteria for Adverse Events V4.03 (CTCAE) [START_REF]Common Terminology Criteria for Adverse Events[END_REF].

Individual patient participation lasted 9 weeks, the duration of the first 3 cycles of FEC 100 cycles of chemotherapy. Patients were included from November 2015 to April 2018 in CGFL.

Statistical analysis

Primary objective and the secondary objectives analysis were carried out in intention to treat population and were repeated on the per-protocol population.

Continuous variables were described using means with standard deviations (SD) and medians with ranges. Comparisons between the two arms were done using the Wilcoxon test.

Categorical variables were described by their frequency (percentage) and compared by a Chi2 test or Fisher exact test.

Quality of life scores were described at each visit in both arms by means with standard deviations and medians with ranges. Mean scores at inclusion were compared using a Wilcoxon test. To study the temporal evolution of quality of life scores, non-parametric mixed models for repeated measures were performed for each of QoL score.

Statistical analyses were performed using SAS version 9.4. All tests were two-sided, and P values < 0.05 were considered statistically significant.

RESULTS

Study flow and population characteristics

94 patients were included and randomized. 54 patients were allocated to the VOM (experimental group) and 40 patients to the superficial manipulation (placebo group). 5 patients in the experimental and 3 patients in the placebo group discontinued the study. 13 patients in the experimental and 12 in the placebo group did not meet at least one of the inclusion/noninclusion criteria. These patients were excluded from the per protocol analysis (experimental group N=41; placebo group N=28) but not from the ITT analysis (experimental group N=54; placebo group N=40) (Figure 1). Median age at inclusion was 57.5 [min=32. 1-max=71.8] in the experimental and 53.1 [min=27.7-max=76.9] in the placebo group. Median age at diagnosis was 57.3 [min=31.9 -max=71.6] in the experimental and 52.9 [min=27.6 -max=76.5] in the placebo group. No significant differences were found between group's age at inclusion or diagnosis. No patient died during the study (Table 1).

Effect of visceral osteopathic manipulation on nausea and vomiting and constipation

Report rate of at least one episode of nausea and/or vomiting of grade 1 or higher, on any of the first 3 cycles of FEC 100, was 80.4% in the experimental versus 87.2% in the placebo group (Table 2). Report rate of at least one episode of constipation of grade 1 or higher, on any of the first 3 cycles, was 47.1% in the experimental versus 61.5% in the placebo group.

No significant differences between the rate of nausea and/or vomiting and constipation were found between groups according to the clinician reported side-effects using the CTCAE (Fisher's test-p-value 0.569 for nausea and/or vomiting and 0.204 for constipation) (Table 2).

Per protocol analysis led to similar results.

QoL

Score description

The rate of EORTC QLQ-C30 questionnaire filling at inclusion and during the first 3 cycles of chemotherapy ranged from 92.6% to 100% (Table 3). A total of 376 observations were done, representing 4 observations for each of the 94 patients at inclusion and during the first 3 cycles of chemotherapy. 85% of QLQ-C30 questionnaires were totally completed, 10% were partially completed and 5% were completely missing.

Experimental and the placebo groups had similar baseline QLQ-C30 scores in all domains (Table 4). Global Health status, nausea and vomiting, constipation and diarrhoea QLQ-C30 scores evolution during the first 3 cycles is represented in Figure 2 (B to E). Median delay between inclusion and cycle 1 was 16 days [min=0-max=49], while median delay between cycle 1 and 2 and cycle 2 and 3 was 21 days ([min=20-max=31]; [min=11-max=42] respectively) (Figure 2 A). Approximately, cycle 1 took place 2 weeks after inclusion, cycle 2 five weeks upon inclusion and cycle 3 eight weeks post-inclusion (Figure 2 A).

Global health status QLQ-C30 scores were similar and remained constant over the time/chemotherapy cycles in both groups (Figure 2 B). Nausea and vomiting QLQ-C30 scores significantly progressed (p<0.0001) over time/chemotherapy cycles in both groups (Figure 2 C). Intestinal symptoms (constipation and diarrhoea) QLQ-C30 scores were statistically significantly higher in placebo (constipation p=0.036; diarrhoea p=0.038) than in experimental group (Figure 2 D andE).

Concomitant treatments

No statistically significant differences concerning the use of concomitant medicines to treat constipation (bisacodyl, macrogol 4000, macrogol 3350, lactulose, glycerin suppository) and diarrhoea (loperamide hydrochloride, racecadotril, diosmectite) were observed between both groups. Nevertheless, there was a tendency to have a higher rate of anti-constipation medicines prescribed to the placebo group in cycle 2 and 3 (41.2% versus 53.8% cycle 2; 38.8% versus 47.2% cycle 3 for experimental and placebo groups respectively) (Table 5).

DISCUSSION

In this study, clinicians reported a high rate of nausea/vomiting episodes, of grade 1 or higher, in patients undergoing adjuvant chemotherapy despite a prophylactic anti-emetic regimen. VOM does not seem to reduce the nausea/vomiting episodes resistant to anti-emetic treatment. Impairment of patient reported QoL due to nausea/vomiting symptoms remains unchanged after VOM. Concerning constipation, physician reported rate of this adverse-event did not decrease upon VOM. In contrast, patient reported QoL impairment due to constipation was significantly reduced by VOM, when compared to a superficial manipulation. In agreement with this observation, patients submitted to the placebo manipulation had a tendency to require more frequently anti-constipation medicines. Therefore VOM might reduce patient reported digestive toxicities induced by adjuvant chemotherapy and obviate medication usage.

Despite its randomized, double-blind, parallel and controlled nature, there are a number of limitations which need to be addressed in a future study. Patient number was not identical in the two groups. Indeed, due to the relatively small sample size, the simple randomization technique used resulted in an unequal number of participants among groups. Additionally, this was a monocentric study, involving only one osteopath practitioner in all the manipulations. Although, VOM is a an accepted and reproducible technique, a multicentre study involving several osteopathy practitioners and larger patient numbers will be required to confirm study results.

Despite the effectiveness of antiemetic regimens, there are still patients who are not protected from nausea and vomiting. A recent report by Tamura et al. showed that 52% of patients subjected to chemotherapy presented nausea and vomiting, despite the prophylactic use of anti-emetics [START_REF] The | Breakthrough chemotherapy-induced nausea and vomiting: report of a nationwide survey by the CINV Study Group of Japan[END_REF]. In this study, the severity of emesis and nausea was reported by the patient using a visual analogue scale (VAS). In our study, clinicians reported a high rate of nausea/vomiting episodes (≥80%). As assessment strategies are different, comparison between studies is not possible. It should be noted that in our study the majority of nausea and vomiting episodes were grade 1 and might be linked to food disgust (results not shown).

Moreover, our population is exclusively composed of women and female gender seems to be a risk factor for chemotherapy induced emesis [START_REF] Hesketh | Evaluation of risk factors predictive of nausea and vomiting with current standard-of-care antiemetic treatment: analysis of two phase III trials of aprepitant in patients receiving cisplatin-based chemotherapy[END_REF][START_REF] Warr | Prognostic factors for chemotherapy induced nausea and vomiting[END_REF].

Osteopathy/massage and relief of chemotherapy induced nausea/vomiting

In our study, both clinician and patient reported data indicate that VOM is not able to reduce nausea/vomiting episodes resistant to anti-emetic treatment. A study by Billhult et al. reported that massage significantly reduced nausea, compared to control treatment, in 39 women with breast cancer undergoing chemotherapy. Massage consisted on soft strokes, lasting for 20 minutes, on foot/lower leg or hand/lower. Control patients were visited by a member of the hospital staff for an unstructured conversation about any subject [START_REF] Billhult | Massage relieves nausea in women with breast cancer who are undergoing chemotherapy[END_REF]. Another study on 17 women reported that finger acupressure may decrease nausea among women undergoing chemotherapy for breast cancer [START_REF] Dibble | Acupressure for nausea: results of a pilot study[END_REF]. A qualitative study described the experience of 16 cancer patients that received osteopathic treatment for the management of cancer-related symptoms in palliative care [START_REF] Steel | The perceptions and experiences of osteopathic treatment among cancer patients in palliative care: a qualitative study[END_REF]. Patients described beneficial effects on pain but also on other symptoms such as constipation or fatigue. A recent randomized clinical trial (RCT) studied the impact of an osteopathic treatment on the QoL of in 40 cancer patients undergoing chemotherapy. A significant reduction of nausea was observed with osteopathy [START_REF] Favier | Évaluation de l'efficacité d'un traitement ostéopathique sur les effets secondaires et la qualité de vie de patients sous chimiothérapie Essai clinique multicentrique randomisé[END_REF]. Osteopathic treatment in this study consisted on a muscular, articular or myo-fascial cephalic, thoracic or abdominal osteopathic treatment adapted to patient's motility dysfunctions. Treatment was then completed by the systematic application of the visceral therapeutic osteopathic manipulation.

Moreover studied populations are different in both studies: while our study included exclusively patients with breast cancer, a heterogeneous population concerning tumour localization was evaluated in Favier et al. Consequently, although chemotherapy regimens characterization is lacking in Favier et al, these were probably heterogeneous. Additionally, no information on the antiemetic treatment is provided in this study. The differences mentioned, render the comparison between studies results difficult.

Osteopathy and relieve of constipation

Research on patient reported outcomes (PROs) in cancer treatment shows that constipation is one of the most common side effects of cancer therapy [START_REF] Gibson | Cancer chemotherapy-induced diarrhoea and constipation: mechanisms of damage and prevention strategies[END_REF]. The use of a serotonin receptor antagonist, included as an anti-emetic, increases the severity of constipation [START_REF] Eisenberg | Improved prevention of moderately emetogenic chemotherapy-induced nausea and vomiting with palonosetron, a pharmacologically novel 5-HT3 receptor antagonist: Results of a Phase III, single-dose trial versus dolasetron[END_REF]. Our results show that patient reported QoL impairment due to constipation was significantly reduced by VOM, when compared to a superficial manipulation. Studies evaluating nonpharmacological interventions for managing chemotherapy-related gastro intestinal symptoms tend to focus on nausea and vomiting and exclude other relevant gastro intestinal symptoms [START_REF] Cherwin | Systematic Review of Nonpharmacologic Approaches for the Management of Gastrointestinal Symptoms[END_REF]. Two pilot studies reported beneficial effects of osteopathy in chronic constipation. Belvaux et al. reported that osteopathic manipulative treatment decreased abdominal pain, bloating and patient assessment of constipation quality score in women with chronic constipation [START_REF] Belvaux | Osteopathic management of chronic constipation in women patients. Results of a pilot study[END_REF]. In a different study, participants reported an improvement in the overall severity of constipation, symptoms and QoL upon osteopathic treatment [START_REF] Brugman | The effect of Osteopathic Treatment on Chronic Constipation -A Pilot Study[END_REF].

Discordance between clinicians and patient reported symptoms

In our study, no discrepancy was observed between clinician and patient reported effect of osteopathy in nausea/vomiting induced by chemotherapy. However, concerning constipation, patients reported a beneficial effect of VOM, while results based on clinician symptom report show no significant differences. Clinicians register side-effects during cancer treatment using CTCAE [START_REF]Common Terminology Criteria for Adverse Events[END_REF]. Several studies have consistently shown that health care professionals (HCP) underestimate the incidence and severity of patients' symptoms, when compared with PROs [START_REF] Litwin | Differences in urologist and patient assessments of health related quality of life in men with prostate cancer: results of the CaPSURE database[END_REF][START_REF] Petersen | Assessing health-related quality of life in palliative care: Comparing patient and physician assessments[END_REF][START_REF] Cirillo | Clinician versus nurse symptom reporting using the National Cancer Institute-Common Terminology Criteria for Adverse Events during chemotherapy: results of a comparison based on patient's selfreported questionnaire[END_REF][START_REF] Basch | Patient versus clinician symptom reporting using the National Cancer Institute Common Terminology Criteria for Adverse Events: results of a questionnaire-based study[END_REF][START_REF] Maio | Symptomatic Toxicities Experienced During Anticancer Treatment: Agreement Between Patient and Physician Reporting in Three Randomized Trials[END_REF][START_REF] Fromme | How Accurate Is Clinician Reporting of Chemotherapy Adverse Effects? A Comparison With Patient-Reported Symptoms From the Quality-of-Life Questionnaire C30[END_REF]. Moreover the agreement between HCPs and patient reported symptoms incidence and severity seems to be dependent on the type of symptom being evaluated [START_REF] Cirillo | Clinician versus nurse symptom reporting using the National Cancer Institute-Common Terminology Criteria for Adverse Events during chemotherapy: results of a comparison based on patient's selfreported questionnaire[END_REF]. Indeed, agreement between HCP and patient reported symptom severity is very high for nausea and low for constipation [START_REF] Cirillo | Clinician versus nurse symptom reporting using the National Cancer Institute-Common Terminology Criteria for Adverse Events during chemotherapy: results of a comparison based on patient's selfreported questionnaire[END_REF].

Osteopathic manual therapy is clearly an essential component of osteopathic health care but it can be combined with other treatments or advice [START_REF]Benchmarks for training in Osteopathy[END_REF]. As we have specifically addressed the effect of a particular manual therapy, it can be expected that the impact of osteopathy in the management treatment related adverse events in real life might be stronger.

LEGENDS

DELAY (days)

Figure 1 :

 1 Figure 1: Study Flow.

Figure 2 :

 2 Figure 2: QoL score description. General health status (B), nausea/vomiting (C), constipation (D) and diarrhoea (E) score evolution upon time. Mean time length delay between inclusion and treatment cycles (A).

Figure 1 :Figure 2 :

 12 Figure 1: Study Flow.

Table 1 :

 1 Patient demographic characteristics.

Table 2 :

 2 Rate of patients reporting at least one episode of nausea and/or vomiting or constipation of grade equal or superior to 1 in one of the first 3 cycles of FEC 100.

Table 3 :

 3 EORTC QLQ-C30 questionnaire filling rate at inclusion and during the first 3 cycles of chemotherapy.

Table 4 :

 4 Patient quality of life at inclusion (EORTC QLQ-C30).

Table 5 :

 5 Concomitant treatments of constipation and diarrhoea in experimental and placebo groups during cycle 1, 2 and 3 of chemotherapy.

TABLE 1 :

 1 Patient demographic characteristics.

		EXPERIMENTAL GROUP	PLACEBO GROUP	p-value
		(visceral osteopathic	(superficial/soft tissue
		manipulation)	manipulation)
		N=54	N=40
	Age at inclusion
	Mean (SD)	57.2 (10,2)	54.4 (12.1)
	Median [min -max]	57.5 [32.1 -71.8]	53.1 [27.7 -76.9]	0.259 a
	Age at diagnosis
	Mean (SD)	56.8 (10,1)	54.3 (12)
	Median [min -max]	57.3 [31.9 -71,6]	52.9 [27.6 -76.5]	0.297 a
	Death
	No	54 (100%)	40 (100 %)

a Wilcoxon

TABLE 2 :

 2 Rate of patients reporting at least one episode of nausea and/or vomiting or constipation of grade equal or superior to 1 in one of the first 3 cycles of FEC 100.

		EXPERIMENTAL GROUP	PLACEBO GROUP	p-value
		(visceral osteopathic	(superficial/soft tissue
		manipulation)	manipulation)
		N=54 §	N=40 #
	Nausea and / or vomiting
	No	10 (19.6 %)	5 (12.8 %)
	Yes	41 (80.4 %)	34 (87.2%)	0.569 b
	95% CI	[0.669 -0.902]	[0.726 -0.957]
	Constipation
	No	27 (55.9 %)	15 (38.5 %)
	Yes	24 (47.1%)	24 (61.5 %)	0.204 b
	95% CI	[0.329 -0.615]	[0.446 -0.766]

b Fisher, § m.d=3, # m.d= 1, m.d missing data

TABLE 3 :

 3 EORTC QLQ-C30 questionnaire filling rate at inclusion and during the first 3 cycles of chemotherapy.

	EXPERIMENTAL GROUP	PLACEBO GROUP
	(visceral osteopathic	(superficial/soft tissue
	manipulation)	manipulation)
	INCLUSION
	N=54	N=40
	54 (100 %)	40 (100 %)
	CYCLE 1
	N=54	N=39
	50 (92.6 %)	39 (100 %)
	CYCLE 2
	N=51	N=39
	50 (98 %)	39 (100 %)
	CYCLE 3
	N=49	N=37
	48 (98 %)	36 (97.3 %)

TABLE 5 :

 5 Concomitant treatments of constipation and diarrhoea in experimental and placebo groups during cycle 1, 2 and 3 of chemotherapy.

	CONCOMITANT	EXPERIMENTAL GROUP	PLACEBO GROUP	p-value
	TREATMENT	(N=54)	(N=40)
		Cycle1
	CONSTIPATION	28 (53.8%)	24 (61.5%)	0.463 a
	m.d	2	1
	DIARRHOEA	2 (33.3%)	1 (14.3%)	0.559 b
	m.d	48	33
		Cycle 2
	CONSTIPATION	21 (41.2%)	21 (53.8%)	0.233 a
	m.d	3	1
	DIARRHOEA	3 (20%)	1 (9.1%)	0.614 b
	m.d	39	29
		Cycle 3
	CONSTIPATION	19 (38.8%)	17 (47.2%)	0.436 a
	m.d	5	4
	DIARRHOEA	4 (26.7%)	1 (10.0%)	0.615 b
	m.d	39	30
	m.d missing data;

a Chi 2 ; b Fisher

ACKNOWLEDGEMENTS

Medical writing and editorial assistance were provided by Isabel Grégoire, PhD, Centre Georges François Leclerc.

FUNDING

This study was funded by Hoffmann-La Roche.

ETHICS STATEMENT

Study was approved by the local ethics committee, authorized by the French Health Agency (ANSM-Agence Nationale de la Sécurité du Médicaments et des produits de santé", n°: 2015-A00366-43) in May 2015, and by the French Ethical Research Committee -"Comité de Protection des Personnes (CPP Est N° 15.04.03) in June 2015. All subjects were informed about the procedures of the study and signed a consent form before any procedure.

DATA AVAILABILITY STATEMENT

All relevant data are within the paper.

CONFLICT OF INTERESTS

No conflicts of interest were disclosed by authors.