INTRODUCTION: Airsickness (AS) affects many aviators and has been associated with hormonal and other biomarker variations. An analysis of hormones and biomarkers potentially predicting an individual’s adaptation to AS was performed.

METHODS: Plasma levels of vasopressin, cortisol, ghrelin, C-reactive protein, substance P, antioxidant capacity, and 15-F2t-isoprostane were analyzed in seven student pilots (five men and two women) affected with incapacitating AS and undergoing a rehabilitation program. Peripheral blood was sampled before and after a nauseogenic Coriolis Stress Test (CST) at the beginning and end of rehabilitation.

RESULTS: All individuals were sensitive and vomited upon initial CST, while no symptoms were provoked by the final one. No significant differences between men and women were observed. After return to real flight activity, one man was still affected with AS (fail case). Higher levels of vasopressin and ghrelin were detected in this individual before the initial CST, with respect to the rest of the sample. A cortisol peak was observed in all subjects after the initial CST (average from 6288–29,861 pg · mL⁻¹), but only in the fail case at the final CST (from 10,040–63,050 pg · mL⁻¹). No relevant changes were observed for C-reactive protein, substance P, and antioxidant capacity, but 15-F2t-isoprostane was significantly reduced after rehabilitation in all subjects with respect to the first recording.

DISCUSSION: Although various hormonal/biomarker changes can be observed during rehabilitation from AS, cortisol plasma levels were noted as a potentially promising parameter for predicting the success of desensitization.

Greco A, Verde P, De Nuccio C, Spanu C, Minghetti L, Lucertini M. Hormones and biomarkers in student pilots before and after rehabilitation from airsickness. Aerosp Med Hum Perform. 2025; 96(6):461–468.

INTRODUCTION: Pilots often experience acute stress during flights, potentially affecting flight safety. The effect of acute stress on instrument-based tasks remains unclear. This study aimed to investigate the influence of acute stress on subjects’ performance in two crucial tasks: the attitude recovery task and the landing judgment task.

METHODS: A total of 91 student pilots were divided into a control group and a stress group. Both groups completed a square task, with the stress group exposed to high-intensity noise to induce acute stress. Subsequently, 42 subjects performed an attitude recovery task using two formats of the attitude indicator: moving horizon and moving aircraft. The remaining 49 subjects performed a landing judgment task with three complexity levels using a landing instrument. Heart rates, trait-state anxiety scores, response times, and accuracy of the tasks were analyzed.

RESULTS: Heart rates and state anxiety scores increased following stress induction. In the attitude task, the stress group responded faster than the control group in the moving-horizon format (467.55 ms vs. 491.45 ms) but had lower accuracy (98.65% vs. 99.73%). In the moving-aircraft format, response times (stress: 454.15 ms, control: 474.73 ms) and accuracy (stress: 98.55%, control: 99.38%) showed no significant differences between the two groups. In the low-complexity landing task, the stress group (1015.79 ms) responded faster than the control group (1168.17 ms).

DISCUSSION: The impact of acute stress on performance depends on task complexity and stress intensity. While stress impairs performance in complex tasks by increasing errors, it enhances performance in simpler tasks by accelerating responses without compromising accuracy.

Jiang H, Jiang H, Wang Q, Peng X, Wang Q, Zhu Q, Yang J. Pilot performance in instrument-based tasks under acute stress. Aerosp Med Hum Perform. 2025; 96(6):469–477.

INTRODUCTION: Given the unpredictability of personnel, equipment, and the aerospace environment, the alarm interface serves as a crucial tool for providing operators with diagnostic, predictive, or guiding information to enhance aerospace safety. The specific relationship between color attributes such as hue, brightness, and saturation of interface warning colors and human stress responses remains unclear.

METHODS: A simulated space station warning interface color experiment was conducted with 80 volunteers possessing normal color vision using a head-down position. The selected 27 red warning colors were evaluated based on response time and performance accuracy metrics.

RESULTS: The findings revealed that each individual variable (hue, brightness, and saturation) significantly affected reaction time, although they did not significantly influence response accuracy. Further analysis of reaction times under simulated microgravity conditions showed optimal reaction performance at a hue of H = 0 and a brightness level of 75%. Additionally, increased saturation was associated with improved color reaction performance.

DISCUSSION: This research provides new empirical evidence regarding the effects of different warning color attributes on human performance in microgravity conditions, offering valuable insights for the design of warning systems in future spacecraft environments.

Yao X, Gan Y, Jiang A, Shen Y. Spacecraft alarm interface color and human performance association. Aerosp Med Hum Perform. 2025; 96(6):478–484.

INTRODUCTION: The remote tower system is a new mode of air traffic control operation that solves many prominent problems in civil aviation operations. The most important concern is the safety of the remote tower. Therefore, to effectively evaluate the safety of remote tower system operations, this paper discusses and analyzes the workload of controllers in remote towers from the perspective of human factors.

METHODS: Front-line controllers were selected as subjects to conduct control command under two control modes, traditional physical and remote tower. Heart rate variability and NASA-Task Load Index data were obtained from controllers and analyzed.

RESULTS: The results showed that there were no significant differences in standard deviation of NN intervals (SDNN), root mean square of successive differences (RMSSD) between adjacent NN intervals, percentage of successive RR intervals that differ by more than 50 ms (PNN50) indexes, and NASA-Task Load Index data between the two control modes. The SDNN index had a significant positive correlation with the RMSSD index. There was a significant positive correlation between the SDNN index and the PNN50 index. The RMSSD index was positively correlated with the PNN50 index.

DISCUSSION: Compared with traditional physical tower control, controllers in this study had no extra workload increase when carrying out remote tower control. Based on the analysis of objective heart rate variability indexes and subjective workload estimates of controllers in this study, it can be preliminarily judged that the operational safety of remote towers appears to be comparable to that of traditional physical towers.

Shen H, An Z, Lu T, Wang Y, Li W-C. Objective and subjective workload of remote and physical tower controllers. Aerosp Med Hum Perform. 2025; 96(6):485–489.

INTRODUCTION: Military aviators have long undergone enhanced medical screening to minimize accidents and deaths. U.S. Army aviators undergo a rigorous initial screening process followed by annual medical evaluations governed by published standards of medical fitness which are updated periodically. An aeromedical summary is submitted for disqualifying conditions, resulting in either a waiver of the standard or suspension of flight status. This study aimed to identify the most common disqualifying medical conditions in U.S. Army aviators in recent years and analyze trends over time.

METHODS: A retrospective observational study was performed using 5 yr of data from the U.S. Army’s Aeromedical Epidemiological Data Repository. Incidence rates for the 10 most common disqualifying conditions, and the waiver approval rate for those conditions, were calculated. Annual incidence was calculated for hypertension aeromedical summary submissions.

RESULTS: Lumbar and cervical spinal disorders (101.55 and 39.26 per 10,000 aviator-years, 81.6% and 79.1% waived, respectively), obstructive sleep apnea (62.00 per 10,000 aviator-years, 93.4% waived), hearing loss (27.96 per 10,000 aviator-years, 98.0% waived), and hypertension (26.13 per 10,000 aviator-years, 97.3% waived) were the most common conditions submitted. Psychological diagnoses were also common, with post-traumatic stress disorder, anxiety and phobias, adjustment disorder, and mood disorders having a cumulative incidence of 44.20 per 10,000 aviator-years and a waiver rate of 45.4%. Submissions for hypertension substantially decreased starting in 2019.

DISCUSSION: Spine disorders are among the leading disqualifying conditions in U.S. Army aviators and metabolic conditions were submitted less often than previously reported, likely due to changes in aeromedical policy with respect to hypertension.

Simmons EA, Lee A, Kelley A. The most common disqualifying medical conditions in Army aviators, 2016–2020. Aerosp Med Hum Perform. 2025; 96(6):490–495.

INTRODUCTION: Novel ocular findings have been identified in spaceflight. We discuss their potential association with Spaceflight Associated Neuro-ocular Syndrome (SANS) and integrate them in a framework that may help explain the pathophysiology.

METHODS: We reviewed literature using the Medline/PubMed database starting in October 2020. Search terms included ocular circulation, hyperopia, serous chorioretinopathy, pigment epithelial detachment, choroidal folds, choroidal thickening, pachychoroid disease, optic disc edema, venous overload choroidopathy. No date exclusions were placed on the search. Articles were reviewed for relevance. Articles relevant to the pathophysiology of choroidal thickening and choroidal venous overload as it applies to SANS were included.

RESULTS: Terrestrial venous overload choroidopathy is thought to be due to impediment to choroidal venous outflow, resulting in dilation of choroidal veins, increased choroidal thickness, pigment epithelial detachments, and serous detachment of the retina. Serous detachment of the retina, pigment epithelial detachments, choroidal folds, and thickening of the choroid were identified on in-flight optical coherence tomography testing. Postflight findings include these, as well as globe flattening. During spaceflight, there is a cephalad displacement of both blood and cerebrospinal fluid. This may lead to pathological consequences in the eye. Remodeling of the choroidal venous vortex system may result in continuance of pathophysiological findings after return to Earth, suggesting the best strategy is prevention.

DISCUSSION: Microgravity induced venous overload of the choroid may play a role in SANS pathophysiology, and a venous overload choroidopathy may help explain several SANS features that remain unexplained by an etiology of elevated intracranial pressure.

Mampre D, Spaide R, Mason S, Van Baalen M, Gibson CR, Mader TH, Wostyn P, Briggs J, Brown D, Lee AG, Patel N, Tarver W, Brunstetter T. Spaceflight-Associated Neuro-ocular Syndrome as a potential variant of venous overload choriodopathy. Aerosp Med Hum Perform. 2025; 96(6):496–508.

INTRODUCTION: The transition to exploration missions places a heightened risk on behavioral health in spaceflight. Although serious psychiatric emergencies during spaceflight have been rare, longer duration missions increase the possibility of emergence in latent mental health disorders due to genetic predisposition, increased autonomy, isolation, helplessness, loss of family member, or catastrophic events. Complicated grief and bereavement have the highest rate of suicidal ideation. Recently, ketamine has been used as an emergent intervention for acute suicidality, promoting its stability, ease of administration, favorable safety profile, and outcomes for reduction of suicidal intent. The goal of this study was to review current literature and collate the understanding of ketamine as a safe, effective pharmacological adjunct for acute suicidality in spaceflight.

METHODS: This literature review was conducted to collate data on ketamine use for acute suicidality and inform on stability, limitations, and utilization of ketamine within extreme environments.

RESULTS: There were 122 publications reviewed for relevance, including 23 randomized-control trials for ketamine use in behavioral emergencies.

DISCUSSION: Ketamine is a diverse pharmaceutical with multiple advantageous indications, including acute suicidality, pain, and sedation. Terrestrial use of ketamine suggests a rapidly efficacious medication for reduction in acute suicidality. As behavioral stressors expand related to extended missions, contingencies for behavioral emergencies become increasingly important. Although this review is not intended to redevelop current International Space Station protocols, it is the first to discuss the benefits of ketamine in spaceflight as a potential safe, effective, multifaceted tool for exploration missions and treatment for acute suicidal ideation.

Kutz CJ, Mistry AM, Dukes CH. Expanding ketamine application for treatment of acute suicidality in long-duration spaceflight. Aerosp Med Hum Perform. 2025; 96(6):509–519.

INTRODUCTION: Asthma is a common diagnosis in the general population and, among military aviators, has the potential for significant aeromedical complications. The objectives of this study, undertaken by the North Atlantic Treaty Organization (NATO) Aviation Pulmonology Working Group (RTG299), were to determine: 1) the prevalence of asthma among trained NATO pilots; 2) agency screening procedures and policies for candidates with a history of asthma; and 3) aeromedical disposition of trained pilots diagnosed with asthma, including allowable medications.

METHODS: A questionnaire was distributed to each participating NATO agency to retrieve information related to each of the above questions.

RESULTS: Data were received from 7 agencies spanning over half a million pilot years (520,369). The prevalence of asthma among serving NATO pilots was surprisingly low at 0.04%, an order of magnitude lower than the general U.S. military (1–2%) and U.S. population in general (approx. 8%). The reported prevalence in U.S. Air Force pilots was inexplicably low at 0.007%. All agencies, apart from the U.S. Air Force, include pulmonary function screening for pilot candidates. Most agencies accept candidates with a history of childhood asthma if full and sustained remission is confirmed with enhanced screening. In trained pilots, most agencies permit the use of medications to control asthma, including inhaled corticosteroids and long-acting beta agonists.

DISCUSSION: The incidence of asthma in NATO pilots was very low. Most NATO pilots diagnosed with asthma were retained on flying status, with some agencies imposing restrictions (generally from high-performance aircraft).

Gray G, Bushby A, Fritjers E, Guettler N, Lindergard K, Naylor J, Regn D. Asthma in military pilots. Aerosp Med Hum Perform. 2025; 96(6):520–524.

BACKGROUND: Fabry disease (FD) is a rare, X-linked lysosomal storage disorder caused by deficient alpha-galactosidase A (alpha-Gal A) activity, leading to the accumulation of glycosphingolipids and resulting in a wide spectrum of systemic symptoms, including neurological, renal, cardiovascular, and cerebrovascular manifestations. While the disease affects approximately 1 in 100,000 individuals, its incidence may be underreported, and no cases in aviators have previously been documented.

CASE REPORT: A 30-yr-old U.S. Air Force C-5 pilot with a family history of FD was diagnosed with a pathogenic galactosidase alpha gene variant after genetic testing. Initial evaluations revealed proteinuric kidney disease and an otherwise normal neurological workup indicating early FD, prompting initiation of lisinopril, clopidogrel for stroke prevention, and the newly Food and Drug Administration-approved chaperone therapy migalastat. The patient tolerated treatment well with appropriate response to therapy as demonstrated by improved biochemical parameters (alpha-Gal A activity and plasma globotriaosylsphingosine levels) and clinical stability. After 8 mo of multidisciplinary monitoring and comprehensive evaluation, he was granted a time-limited aeromedical waiver and successfully returned to flying duties.

DISCUSSION: FD is a rare, progressive genetic disorder caused by galactosidase alpha gene variants, resulting in alpha-Gal A deficiency and glycosphingolipid accumulation, leading to neurological, renal, cardiac, and cerebrovascular complications. Despite higher aeromedical risks, especially due to stroke and cerebrovascular issues, FD patients may qualify for restricted flight duties under close monitoring and multidisciplinary care. Continued evaluation of novel therapies and individualized aeromedical waivers can support aviators with FD while balancing safety and operational requirements.

Carlock T, Kincaid-Sharp E, Orsello C, Ford AW, El-Khoury BB. Navigating Fabry disease in a military aviator. Aerosp Med Hum Perform. 2025; 96(6):525–529.

INTRODUCTION: From Mars, the Earth will appear as an insignificant dot in the heavens and two-way communication with family and mission control can take up to 44 min. The resulting impact of these restrictions on crewmembers may be termed the Earth-disconnect phenomenon. The literature suggests that seeing the Earth as a beautiful orb in space is an awe-inspiring experience (the Overview Effect), the loss of which may produce isolation and loneliness. Not being able to communicate with family and mission control in real time may produce emotional distress and impaired performance. Strategies to help crewmembers deal with these issues include using a telescope or virtual reality to better experience the Earth and suggesting future response topics and using more formal messaging techniques to improve communication efficiency. More study needs to be done using simulators, a space station, or the far side of the Moon to better understand this phenomenon.

Kanas N. The Earth-disconnect phenomenon as a psychological stressor for Martian crewmembers. Aerosp Med Hum Perform. 2025; 96(6):530–532.