INTRODUCTION: On December 2020 the U.S. Food and Drug Administration (FDA) authorized the emergency use of Pfizer-BioNTech COVID-19 vaccine. This new vaccine has several side effects that can potentially impair function, which warrants special attention regarding aircrews’ fitness to fly following vaccination.

METHODS: A survey was conducted in the Israeli Air Force (IAF) Aeromedical Center in order to characterize the side effects and their duration following Pfizer-BioNTech COVID-19 vaccine administration to aviators.

RESULTS: The most common side effect was injection site pain. Headache, chills, myalgia, fatigue, and weakness were more common following the second dose administration. The difference is statistically significant. Following the second vaccine, duration of side effects was longer compared to the first vaccine (P-value = 0.002).

CONCLUSION: The IAF Aeromedical center policy for Pfizer-BioNTech COVID-19 vaccine recipients among aircrew members, based on side effects duration and severity, is to temporarily ground from flight duties for 24 and 48 h following the first and the second dose, respectively.

Gabbai D, Ekshtein A, Tehori O, Ben-Ari O, Shapira S. COVID-19 vaccine and fitness to fly. Aerosp Med Hum Perform. 2021; 92(9):698–701.

INTRODUCTION: Military aeromedical evaluations are common, but specialized neuropsychological norms for aviation personnel are sparse, resulting in a need to rely on norms from the general population. Little has been published regarding aviation subpopulations and how their neuropsychological profiles may differ from general population normative data. This study investigated neuropsychological test results of aeromedical service members to evaluate consistency with general population norms, and to delineate differences between aviation subpopulations.

METHODS: Analyses were conducted on demographic variables and test scores of military aviators (N = 26) and nonaviator crewmembers (N = 36) referred for evaluation due to a clinical problem requiring a waiver for flight status. Performance differences between subsamples were investigated with general linear modeling. Base rates for low scores were described.

RESULTS: Mean test scores in both subsamples were 0 to 1 standard deviation (SD) above the general population’s means, with the largest discrepancies being found on measures of visuospatial ability (crewmembers) and verbal learning (aviators). Modeling revealed a significant difference between aviators and crewmembers on Trail Making Test Part B, after accounting for education. Aviators produced fewer low scores than crewmembers, even when using education adjusted normative data.

DISCUSSION: Results suggest the cognitive profile of aviators is uniquely strong in specific domains, with fewer low scores. The development of aviator-specific norms may enhance sensitivity to cognitive decrements in this population. Future studies might separately assess crewmember roles to further assess cognitive performance standards across specialties.

Maltez-Laurienti A, Minniear A, Moore R, McGovern T, Newman P, Brearly T. Exploring neurocognitive performance differences in military aviation personnel. Aerosp Med Hum Perform. 2021; 92(9):702–709.

BACKGROUND: Fatigue of air force pilots has become an increasing concern due to changes in mission characteristics. In the current study we investigated fatigue, emotions, and cognitive performance in a simulated 11-h mission in the 39 Gripen fighter aircraft.

METHODS: A total of 12 subjects were evaluated in a high-fidelity dynamic flight simulator for 12 consecutive hours. Perceived fatigue was measured by the Samn-Perelli Fatigue Index (SPFI). Emotions were assessed with the Circumplex Affect Space. Cognitive performance was assessed by five cognitive tasks.

RESULTS: Significant increase in self-reported fatigue, general decrease in two positive emotional states, as well increase of one negative emotional state occurred after approximately 7 h into the mission. Self-reported fatigue negatively correlated with enthusiasm and cheerfulness (r’= −0.75; −0.49, respectively) and positively correlated with boredom and gloominess (r’= −0.61; r’= −0.30, respectively). Response time in the low-order task negatively correlated with enthusiasm, cheerfulness and calmness (r’= −0.44; r’= −0.41; r’= −0.37, respectively) and positively correlated with boredom and anxiousness (r’= 0.37; r’= 0.28, respectively). Mission duration had an adverse impact on emotions in these environmental conditions, particularly after 7 h.

DISCUSSION: These results contribute to the understanding of fatigue development in general and of emotion-cognition relationships. These findings emphasize that both emotional states and the type of cognitive tasks to be performed should be considered for planning long-duration missions in single-piloted fighter aircrafts as to increase the probability of missions’ success.

Rosa E, Gronkvist M, Kolegard R, Dahlstrom N, Knez I, Ljung R, Willander J. Fatigue, emotion, and cognitive performance in simulated long-duration, single-piloted flight missions. Aerosp Med Hum Perform. 2021; 92(9):710–719.

BACKGROUND: The objectives were to assess the prevalence, severity, and medication taken, and to look for predictive factors in order to better identify characteristics of passengers at risk of motion sickness during transport from Hobart in Tasmania to the French polar stations in Antarctica.

METHODS: There were 239 passengers who were surveyed over 4 yr with 4 round trips per year using the Motion Sickness Susceptibility Questionnaire (MSSQ), Simulator Sickness Questionnaire (SSQ), state-trait anxiety test (STAI-Trait and STAI-State), and general parameters (age, gender, number of trips, jet-lag, direction of the trip), medication, calculation of the distance of each passenger’s cabin to the center of gravity (CoG).

RESULTS: While the passengers had a low intrinsic sensitivity to motion sickness (MSSQ), 94% reported at least one SSQ symptom of motion sickness, and 38% vomited. Five associated factors were discovered: greater initial sensitivity (MSSQ), anticipation of being ill, younger age, higher level of anxiety at midtrip, and greater distance from the CoG. Of the passengers, there were 54% who took anti-motion sickness medication at different times of the trip, however, these passengers experienced more nausea. This could be due to self-selection since they were more sensitive to motion sickness.

CONCLUSION: We identified three predictive factors of motion sickness (greater intrinsic susceptibility, younger age, and greater cabin distance from the CoG). For preventive purposes, two associated factors of MS (anticipation of being ill, MSSQ score) were determined to classify three groups of risk of MS to improve passenger care during the trip.

Besnard S, Bois J, Hitier M, Vogt J, Laforet P, Golding JF. Motion sickness lessons from the Southern Ocean. Aerosp Med Hum Perform. 2021; 92(9):720–727.

BACKGROUND: Glaucoma and ocular hypertension (OHT) are prevalent diseases with baseline intraocular pressure (IOP) elevations that future astronauts and spaceflight participants may suffer from. Preflight, in-flight, and postflight IOP measurements were collected aboard two U.S. Space Shuttle Program missions in normotensive control, OHT, and glaucomatous crewmembers.

METHODS: Five subjects (three controls, one glaucomatous, one OHT) were studied aboard 2-wk Space Shuttle missions. Baseline IOP (triplicate; handheld tonometry) was recorded during training 1–2 mo preflight, in flight (1–14 d), and postflight (3–29 d). Subjective symptoms were recorded via questionnaires. Data were analyzed using a spreadsheet with two-sample t-tests. P-value < 0.05 determined significance.

RESULTS: IOP increased for all in-flight vs. preflight measurements for controls (N = 3, +48.9%, +16.9%, +5.85%), OHT (N = 1, +20.3%), and glaucomatous (N = 1, +32.2%) groups. IOP eventually returned to baseline postflight [Return (R)+3–5 d], except for the astronaut with OHT (R+9–17). Subjective symptoms, likely multifactorial, included blurred vision, decreased visual acuity, and headaches.

DISCUSSION: IOP increased during spaceflight and normalized upon return. Astronauts and commercial spaceflight participants may need screening for elevated IOP to potentially prevent sequelae related to glaucoma and OHT, the former which requires treatment in flight and the latter which may need prophylaxis. Previous studies have shown elevated IOP upon entry into microgravity with various normalization timeframes in flight and postflight. It is unclear how increased IOP relates to spaceflight-associated neuro-ocular syndrome (SANS); however, several hypotheses exist. Treatment strategies should be available for acute and chronic ocular pathology during spaceflight despite the unique challenges of eye-drop application in microgravity.

Dalal SR, Ramachandran V, Khalid R, Manuel FK, Knowles JR, Jones JA. Increased intraocular pressure in glaucomatous, ocular hypertensive, and normotensive space shuttle crew. Aerosp Med Hum Perform. 2021; 92(9):728–733.

BACKGROUND: The following case report describes the first known case of McLeod Syndrome in a commercial airline pilot. The case describes a 56-yr-old experienced pilot who showed a slow and subtle decline in cognitive function and muscle control in the cockpit. On further examination, the pilot’s erratic behavior and movement along with lab abnormalities pointed toward McLeod Syndrome.

CASE REPORT: The pilot was recommended for evaluation by his fellow crewmembers due to his fidgetiness, clumsiness, and lack of focus during critical portions of flight. The pilot reported having a long-standing history of elevated CK levels. Further lab investigations revealed acanthocytes on blood smear while neurological evaluation detected chorea. The combination of clinical and laboratory features along with genetic test results were all consistent with McLeod Syndrome.

DISCUSSION: The case highlights how subtle behavioral and motor coordination changes can be a warning sign for an underlying progressive neurological disorder that requires further workup and referral.

Haas C, Levin D, Milone M, Vardiman-Ditmanson J, Mathers C. McLeod syndrome in a commercial airline pilot. Aerosp Med Hum Perform. 2021; 92(9):734–737.

OBJECTIVE: High altitudes imply exposure to a decreased ambient air pressure. Such a situation may also alter the performance of acoustic transducers using vibrating diaphragms due to air rarefaction. This study aimed at analyzing the performance at high altitude of hearing aids (HAs) where mechano-electric and electro-mechanic transducers are used.

METHODS: A hypobaric chamber was used to perform two separated experimental sessions. In the first one two commercial models of HAs were exposed to a simulated altitude of 25,000 ft (7620 m) and to a subsequent rapid decompression profile, with a rapid climb (< 3 s) from 8000 (2438 m) to 25,000 ft. The second session separately analyzed the performance of microphone and receiver at an altitude of 9000 and 15,000 ft (2743 and 4572 m). Before and after the first session, the HAs were tested with an electronic ear while a dedicated recording system was used in the second session.

RESULTS: No HA damage or dysfunction was detected during the first session. In the second one, the microphone showed a mild decrease of its output, while the receiver exhibited a much higher reduction of its output.

CONCLUSION: Our findings highlight the safe use of HAs even under extreme environmental pressure changes. For altitudes exceeding 10,000 ft (3048 m), a recalibration of the HA’s output via a dedicated program may be suggested.

Lucertini M, Sanjust F, Manca R, Cerini L, Lucertini L, Sisto R. Hearing aids’ performance in hypobaric environments. Aerosp Med Hum Perform. 2021; 92(9):738–743.

INTRODUCTION: In the mid-1970s, NASA required a robust training program for physicians responsible for the medical needs of the Shuttle astronauts. Personnel at NASA worked closely with academicians and subject matter experts at Wright State University (WSU) to develop and establish a residency program in aerospace medicine. This academic training program was initiated in 1978 and closed in 2018. The objective of this historical piece is to catalog, for posterity, the impact this training program has had on national and international human spaceflight and aviation.

METHODS: A thorough review of all available historical documents and oral histories provided by contemporaries were reviewed in detail, including a search of every available resident’s thesis and all available historical documents and reports at WSU and NASA Headquarters.

RESULTS: Over the past 40 yr, WSU has graduated 172 individuals with an M.S. degree focused on aerospace medicine, of which 84 were residents. Nearly 50% of these residents have worked closely with NASA. Many others became integrated into academia, the aviation industry, or international space programs.

DISCUSSION: With the growth in interest for government and commercial spaceflight, the field of aerospace medicine is poised to grow. Although it is not well known outside of the Aerospace Medicine community, the legacy of this pioneering, 40-yr civilian-based program is of significant value. If not recorded in an easily locatable and accessible manner, many of the challenges and outcomes from this residency could be lost until future generations have to spend the money, time, and effort to relearn them.

Doarn CR, Shimada K, Shepanek M. The legacy of the Wright State University Aerospace Medicine Residency program. Aerosp Med Hum Perform. 2021; 92(9):744–750.