Clinical trials

The goal of this study is to investigate whether prospective memory, i.e., memory for delayed intentions, is impaired at moderate altitude (4,000m). It will also allow to study the effect of air and oxygen administration during hypoxia exposure. The main questions it aims to answer are: * Does moderate acute hypoxia impair prospective memory ? * If so, does air or oxygen adminsitration induce a restoration of prospective memory? Researchers will compare cognitive performance during normobaric hypoxia exposure to cognitive performance during normoxia (control situation). Participants will: * Session S0. Perform a battery of neuropsychological tests and questionnaires). EEG will be recorded during tests. A cheek swab will be performed. * Sessions S1 and S2. Perform several cognitive tasks while exposed to hypoxia and to normoxia (2 different sessions, randomized order) in a normobaric chamber. These are standardized cognitive tests administered on a computer and cognitive tests embedded in a flight simulator scenario. Various questionnaires will be performed on a regular basis. Several physiological measurements will be performed continuously: EEG, ECG, SpO2 and breathing rate. Blood pressure will be measured at the beginning and at the end of hypoxia/normoxia exposure. A blood sample will also be performed. At last, participants will inhale air or oxygen through a mask while making a cognitive task in the chamber.

The main objective of this clinical trial is to identify a variation in visual strategy characterized by both head movements and eye movements of healthy volunteers during a target detection task when images simulating night vision goggles (NVG) are presented, compared to a situation in which the images simulate a natural environment. To highlight changes in environmental scanning with simulated images from NVG, objective measurements will be collected: * eye movements characterized by saccades (speed, latency, and number) for each stimulus * head movements (horizontal angle of the participant's head) for each stimulus and throughout the exposure Participants sit facing a screen (9.90 m x 2.10 m) onto which a virtual scene is projected. The objective is to correctly identify, as quickly as possible, a target stimulus (represented by a tank) that may appear in the scene. They must use the directional arrows on a game controller to indicate whether the tank is moving to the left or to the right. There are four visits involving four viewing conditions in which the task remains the same: * With restricted field of view and a normal scene. * Without restricted field of view and a scene simulating the vision obtained by NVGs. * With restricted field of view and a scene simulating the vision obtained by NVGs. * Without restricted field of view and a normal scene. Regarding the content of the scene, half of the tests in each visit involve a so-called poor scene when fog is simulated, or an enriched scene when there is no fog. Each visit lasts approximately one hour and thirty minutes.

The aim of the study is to describe professional exposures and health events among French military firefighters (both active-duty personnel and veterans) and identify potential relationships between the exposome (the total history of occupational and personal exposures) and health status in these populations. The study is based on a self-administered questionnaire that collects retrospective and present information about exposures and health conditions.

Post-traumatic stress disorder (PTSD) is a pathology that impairs the quality of life of sufferers. In military personnel, it can lead to military incapacity. This psychopathology is characterized by confrontation with one or more traumatic events in the individual's life history. Symptoms include cognitive and mood disorders, avoidance, hyperactivation (hypervigilance and anger) and intrusions (flashbacks and nightmares). Studies show that the prevalence of PTSD in military personnel fluctuates considerably from one situation to another (pre-deployment/post-deployment, etc.). In these at-risk populations, the often more complex PTSD clinic may also account for the heterogeneity of prevalences observed. Nevertheless, PTSD tends to become chronic in military personnel, making it particularly difficult to return to a "previous" state. In French casualties, beyond the symptoms already mentioned, complaints focus on difficulties in social interaction situations involving others in social life (attachment style to others) and in everyday life (public transport, supermarket shopping, social interactions, presence of crowds...). In the context of post-traumatic stress disorder, we would like to explore the processes of social cognition that enable people to interact in their environment, in relation to biological, psychosocial and physiological variables that may constitute risk or maintenance factors for the pathology.

Multivisceral failure syndrome (MVFS) in humans is associated with a very high risk of mortality, ranging between 30 and 50%. This syndrome is associated with significant systemic inflammation and a high risk of bacteremia, the origin of which is not always identified. Among the possible causes of bacteremia, digestive translocation is the most probable but has not been formally proven to date. This translocation is made possible by the numerous cellular and metabolic alterations secondary to MVFS, which can lead to increased intestinal barrier permeability. Intestinal permeability is currently not systematically evaluated in clinical practice in humans. This increased intestinal permeability, associated with the presence of inflammatory markers and a septic state, has been studied in several animal models ranging from the fruit fly (Drosophila) to the mouse. These studies have shown a high risk of mortality associated with increased intestinal permeability. We propose to use this methodology in intensive care patients with at least one organ failure to investigate the link between increased intestinal permeability and survival chances.

The management of head trauma patients requires the assessment of cognitive disorders using standardized neuropsychological tests and questionnaires. However, the evaluation tools currently available present well-identified limitations limiting the accuracy of the measurements (in a non-exhaustive manner, let us cite for example the absence of control of the rate of "false positives" or even the impossibility of measuring the improvement or decline in performance over time). In order to overcome these limitations, the Neuralix battery was created with particular attention to the assessment of memory and executive functions largely impacted after head trauma. The Neuralix battery comes in the form of a digital application accessible online and allowing a global assessment of cognitive functions in adults. In addition, the processing of results includes the operationalization of decision criteria taking into account the limitations cited above in order to improve the sensitivity of the evaluation. The VANOLIX study proposes the validation of the Neuralix cognitive battery with head trauma patients of moderate to severe intensity as well as its standardization with healthy volunteers, these two steps being essential to making the tool available to clinician-researchers.

Since May 2024, New Caledonia has been experiencing a period of crisis. The organisation of the work of military personnel on the ground has been heavily impacted, with longer working hours, shorter rest periods and increased stress levels (uncertainty about the situation, lack of visibility, etc.). Prolonged exposure to stress is accompanied by neuronal damage (Ramdani et al., 2024) and operational fatigue, a mindset that results from reversible neuronal damage and appears to be distinct from exhaustion. The aim of this study is to assess the impact of the crisis on the level of operational fatigue. In addition, identifying the organisational and human factors (Jaspers et al., 2024) that may have been protective against operational fatigue could help to optimise the way in which these factors are taken into account in the event of future crises, in order to promote resilience.

The aim of this study is to identify the effect of the increase of the situation demands, with or without a thread, on military helicopter pilot's cognitive load, depending on their skills acquisition (at the beginning, midway and end of training course). This study is carried out on a simulator, in virtual reality and allows to identify the moments of cognitive load enhancement and the associated indicators such as subjective, physiological and behavioural indicators. Recommendations will be done to go towards an individualization of the lessons during the pilots education, by anticipating an overload which has a deleterious effect on learning.

Military personnel and athletes have a very high energy expenditure, which is increased during certain key periods (intense training, competition and missions). Compensating for this expenditure through adequate energy intake can be complicated by physiological ingestive limits and logistical and organizational constraints (number of meals, food availability), leading these populations to regularly find themselves in an energy deficit situation (intake below requirements). If this situation persists, it could impair physical and cognitive performance, as well as major physiological functions. Among the many constraints to which military personnel and athletes are subjected (stress, sleep deprivation, travel, etc.) that can increase the risk of energy deficiency, the impact of thermal environmental constraints is very imperfectly known. Seasonal impact and travel to countries with very different thermal environments from temperate countries can lead these populations to work in cold and hot conditions for long periods. Understanding how exposure to hot and cold alters appetite and energy intake is therefore of the high importance. Our previous "TEMPCA" study highlighted a modulation of preferences for warm or cold foods depending on the exposure environment. By being able to adapt their food intake to these preferences, subjects were able to maintain a decent energy intake. The primary objective of this study is to determine the effect of the temperature of the food served (hot or cold) on changes in food intake during acute exposure to hot and cold. We hypothesized that adapting the temperature of the food served according to the exposure environment (hot in a cold environment and cold in a hot environment) would enable adequate levels of energy intake. Secondary objectives are to determine the influence of the environment on the levels of interstitial glucose during the preprandial period and to investigate the impact of thermal exposure (modulation of core temperature) on the modulation of quantities consumed and energy produced by digestion (postprandial thermogenesis). Forty participants (between 18 and 40 yo, male or female, active, lean, and healthy) will carry out 3 experimental sessions in which only the thermal environment will differ: cold condition (15°C), neutral condition (25°C) and warm condition (35°C). They will be divided into two groups, the first of which will be offered a cold meal during the three sessions (Cold Meal - CM) and the second a warm meal during the three sessions (Warm Meal - WM). They will all wear the same outfit designed to be offer perfect thermal comfort at 25 °C. Briefly, each session will start at 8:30am after eating a standardized breakfast. Body mass and ad libitum water intake will be frequently monitored to identify possible dehydration. Thermal comfort and sensation and subjective appetite will be regularly assessed using visual analog scale. From 11:00am to 01:00pm, all participants will be isolated and all temporal cues will be removed. At 01:00pm, an ad libitum meal (warm or cold) will be served in large quantities. The dishes will be weighed before and after the meal to assess energy intake. Before and after the meal, resting metabolism will be measured during 30 min in a supine position using indirect calorimetry and food preferences for high-fat/low-fat, savory/sweet, warm/cold foods, and fluid/solid foods will be assessed using the Leeds Food Preference Questionnaire.

• Visit the clinic once every 2 weeks for checkups and tests The goal of this clinical trial is to learn if systematic hearing tests (eg fonctional assesment, electrophysiology and seric biomarkers) can diagnose hidden hearing loss or vestibular troubles in a population of patients treated for cancer; population study will include different population in terms of sex/gender, age, medical condition (cancer patients treated with surgery alone and/or radiotherapy and/or chemotherapy, and healthy volunteers). The main question it aims to answer is: • To assess the ototoxicity of anticancer drugs using a combination of auditory functional tests (including speech audiometry in noise), vestibular test , plasmatic samples and electrophysiological measures. Participants will be studied: Either only after exposition (single visit) Or before, during and after the exposition to potential otototoxic agents with a 4 times Visit the clinic checkups and tests (one before, two while ongoing potential ototoxic agents and 1 post exposition) Participants will complete questionnaires, undergo audiometric and electrophysiological tests, and their routine biomedical data will be studied, without any modification of the routine care (planned cancer treatment)

The EXPLO-MITO study is an ancillary study from the main EXPLO-CCE study (NCT04593316; IDRCB: 2020-A01967-32). The Heat Tolerance Test (HTT) is a physiological exploration that has several advantages for use in research and clinical settings. Unlike the walk-run test, it is performed under controlled conditions, both environmentally (temperature control, humidity, etc.) and in terms of effort intensity. In addition, there are published interpretation criteria for this test allowing to characterize thermoregulation profiles and to distinguish between Heat Intolerant (HI) and Heat Tolerant (HT) patients. The reproducibility of this test and its performance in a climatic chamber allows a true comparison of thermophysiological responses (heart rate, rectal and skin temperatures, skin blood flow and sweat loss), which was not possible with the run-walk test, which was more a field test validating a physical aptitude for recovery (so-called "occupational" test) than a physiological exploration evaluating a response to stress by comparing it with the expected response in a population of young, healthy, properly trained subjects. Moreover, the HTT is a much less physiologically demanding test than the 8-km run. The HTT, which corresponds to a 2-hour walk at 5 km/h with a 2% slope at 40°C and 40% relative humidity, is a so-called "compensable" thermal stress; that is, under these conditions of exercise and environment, when the individual has normal thermoregulatory capacities, a thermal equilibrium plateau is reached during the second hour, when the individual's thermolysis capacities make it possible to compensate for the production of heat by the exercise and the gain of heat related to the environment. On average, this plateau is between 38° and 39°C. This is clearly not the case with our experience of physiological monitoring of the 8-km walk-run which rarely allows a temperature plateau to be reached and is accompanied by a temperature rise constantly above 39°C. In addition to being performed in the laboratory, this test is therefore completely safe. For all these reasons (reproducibility, relevance, predictive value of recurrence), this test has been used for more than 30 years by the Israeli army for the assessment of these cases of exercise heat stroke before their return to work. There is therefore a fair amount of published data and hindsight on the use and interest of this test. The Israeli test has the highest level of recommendation (Grade A) of all the other published heat tolerance tests. Also, the availability of a climatic chamber means that this test can now be proposed as one of the explorations available to clinicians who have to decide on the fitness of soldiers after exercise heat stroke.

In some clinical forms of COVID-19, an uncontrolled hyper-inflammatory reaction known as a "cytokine storm" appears abruptly, around day 7, and is associated with rapid respiratory deterioration, requiring hospitalization in an intensive care unit (ICU). At present, although risk factors for this severe form have been described, there are no validated criteria for determining which individual patients will develop this aggravation. The study of respiratory sounds (amplitude, frequency, ...) has made it possible in other respiratory pathologies (e.g., chronic obstructive pulmonary disease) to predict exacerbations several days in advance. Having a predictive respiratory pattern for worsening in COVID-19 would make it possible to anticipate the need for intensive care hospital beds, by means of a tool easily available on a mobile phone.

Anterior shoulder instability is a chronic condition that occurs after an anteromedial dislocation. Its prevalence is high in athletes but has been little studied in the armed forces. In general, patients with a first episode of dislocation have a 1 in 2 chance of experiencing at least one recurrence. The more recurrences there are, the more damage there is to the joint and the greater the disability for the patient. The decree determining the medical aptitude of military personnel emphasizes the need to have recourse to a specialized consultation to determine the classification of the soldier after a first episode of dislocation. In the absence of data collected specifically in the military population, classification is based on the surgeon's experience and extrapolation of results obtained in the general population.

The impact of oxygen therapy in many pathologies has been subject of recent work, arguing both favourable and harmful effects. Consequently, one can wonder about the influence of hyperoxic gas mixture during diving on the genesis of decompression sickness, but also about the systematic application of normobaric and hyperbaric oxygen in case of proven decompression sickness. In mammals, normoxic concentrations have been redefined at 20-100 mbars at the extracellular level and below 10 mbars in the mitochondria. Under hyperbaric conditions, most of the oxygen being dissolved in blood plasma, a state of hyperoxia is established which escapes the usual delivery and regulation system represented by red blood cells. The results of our team's previous work suggest a specific effect of diving on the levels of circulating mitochondrial DNA (mtDNA), suggesting cellular destruction linked to hyperoxia/hyperbaria. In fact, our studies, carried out on both animals and human divers, have shown that diving accident leads to an increase in mtDNA levels and an immune reaction through the mobilisation of leukocytes. The main objective of this study is to compare the influence of oxygen partial pressure levels on the evolution of clinical and biological variables during hyperbaric oxygen therapy sessions in healthy versus injured divers.

Executive functions are defined as the mental functions necessary for an individual to adapt to a complex or new environment that requires freedom from automatic and routine behavior. Deficits in executive functions are described under the term "dysexecutive syndrome", and call into question the quality of social and professional life as well as the autonomy of patients. The usual methods of identifying dysexecutive syndrome are based essentially on batteries of neuropsychological tests known as "paper and pencil". However, these tests may lack sensitivity, in that they assess the patient in a very structured setting, very different from real life conditions, which are full of distractions and choices to be made. Evaluations on real tasks are more rarely used but have the advantage of observing the difficulties encountered by a patient in everyday life. Two tests of this type have been set up in the Neurology Department of the Hôpital d'Instruction des Armées Percy, and are integrated into the routine care of patients with a dysexecutive syndrome. For this purpose, a room in the department has been set up as a studio in order to reproduce as much as possible an everyday life environment, in which executive functions, fine motor skills, neurovegetative functions, emotional state, posture, locomotor skills and visual information capture can be measured ecologically.

Masquelet's induced membrane technique is a two-stage reconstructive surgery for severe bone fractures commonly used by military orthopedists. The particularity of this technique relies on the synthesis of a biological membrane induced by the transient implantation of a surgical cement (= 1st stage surgery). The presence of the induced membrane in the reconstruction space defines a microenvironment or "biological chamber" favourable to osteogenesis, positively influencing the repair of the lesion after implantation of an autologous bone graft (= 2nd stage of surgery). In view of the excellent clinical results obtained with this procedure, the Masquelet technique has gradually become a reference treatment in the field of orthopedic and trauma surgery. However, orthopedic surgeons sometimes observe failures in bone consolidation. To our knowledge, the role played by induced membrane in these therapeutic failures has never been studied.

The amputation of a limb results in chronic pain associated with the lost limb in the majority of patients, which persists over time. Despite a large number of studies conducted in an attempt to elucidate the neural basis of phantom pain, these are still not elucidated and current treatments often fail to relieve patients' pain.

Immersion Pulmonary Edema (IPE) is a relatively new form of hemodynamic pulmonary edema. The number of cases has been increasing over the last ten years and it has become the second most common cause of hospitalization for military divers, after decompression sickness. The pathophysiological mechanisms of IPE are not completely known. Its occurrence is linked to a combination of factors related to the environmental constraints of diving, as well as to the diver's equipment. The main external factors are increased hydrostatic pressure, cold, intense effort and emotional stress. The impact of internal factors is not known. At this time, no severe forms of IPE have been identified in the military. However, it is important to identify this pathology at an early stage, even if the signs appear minor, because the continuation of underwater activity can significantly worsen the clinical picture. The risk of recurrence (greater than 15%) could result in a severe or even lethal accident.