Acute mountain sickness predicts the emotional state of amateur mountaineers.

Research on amateur mountaineers is scarce, and this study aims to delve into the emotional experiences of ten amateur mountaineers during their ascent using the "Befindlichkeitsskala" (BFS) and Lake Louise Acute Mountain Sickness scoring system (LLS). These subjects were exposed to altitudes of 3140 m, 4300 m, and 5276 m, respectively. We found that LLS scores were negatively correlated with positive emotions (ß = -27.54, p < 0.05) and positively correlated with negative emotions (ß = 21.97, p < 0.05). At an altitude of 4300 m, individuals with AMS exhibited significant differences in depression, anger, excitement, and inactivity compared to climbers without AMS. Upon returning to 3140 m after completing the climb, significant differences were observed in emotions such as happiness, calmness, anger, excitement, and depression. Throughout the three-day climb, noteworthy differences emerged in activity, happiness, calmness, inactivity, positive emotions (p < 0.01), negative emotions, and overall emotional scores (p < 0.05). Our study suggests a decline in the emotional well-being of amateur climbers with increasing altitude, highlighting AMS as a pivotal predictive factor for emotional experiences while climbing.

Acute mountain sickness and sleep disturbances differentially influence cognition and mood during rapid ascent to 3000 and 4050 m.

The impact of acute mountain sickness (AMS) and sleep disturbances on mood and cognition at two altitudes relevant to the working and tourist population is unknown. Twenty unacclimatized lowlanders were exposed to either 3000 m (n = 10; 526 mmHg) or 4050 m (n = 10; 460 mmHg) for 20 h in a hypobaric chamber. AMS prevalence and severity was assessed using the Environmental Symptoms Questionnaire (ESQ) and an AMS-C score ≥ 0.7 indicated sickness. While sleeping for one night both at sea level (SL) and high altitude (HA), a wrist motion detector was used to measure awakenings (Awak, events/h) and sleep efficiency (Eff, %). If Eff was ≥85%, individuals were considered a good sleeper (Sleep+). Mood and cognition were assessed using the Automated Neuropsychological Assessment Metric and Mood Scale (ANAM-MS). The ESQ and ANAM-MS were administered in the morning both at SL and after 20 h at HA. AMS severity (mean ± SE; 1.82 ± 0.27 vs. 0.20 ± 0.27), AMS prevalence (90% vs. 10%), depression (0.63 ± 0.23 vs. 0.00 ± 0.24) Awak (15.6 ± 1.6 vs. 10.1 ± 1.6 events/h), and DeSHr (38.5 ± 6.3 vs. 13.3 ± 6.3 events/h) were greater (p < 0.05) and Eff was lower (69.9 ± 5.3% vs. 87.0 ± 5.3%) at 4050 m compared to 3000 m, respectively. AMS presence did not impact cognition but fatigue (2.17 ± 0.37 vs. 0.58 ± 0.39), anger (0.65 ± 0.25 vs. 0.02 ± 0.26), depression (0.63 ± 0.23 vs. 0.00 ± 0.24) and sleepiness (4.8 ± 0.4 vs. 2.7 ± 0.5) were greater (p < 0.05) in the AMS+ group. The Sleep- group, compared to the Sleep+ group, had lower (p < 0.05) working memory scores (50 ± 7 vs. 78 ± 9) assessed by the Sternberg 6-letter memory task, and lower reaction time fatigue scores (157 ± 17 vs. 221 ± 22), assessed by the repeated reaction time test. Overall, AMS, depression, DeSHr, and Awak were increased (p < 0.05) at 4050 m compared to 3000 m. In addition, AMS presence impacted mood while poor sleep impacted cognition which may deteriorate teamwork and/or increase errors in judgement at HA.

Effects of Hypoxia on Selected Psychophysiological Stress Responses of Military Aircrew.

There is a lack of information on the psychophysiological response of pilots under hypoxic conditions. The study of the physiological, psychological, cardiorespiratory, neurological, behavioural, sensory, and cognitive symptoms that may appear during training in hypobaric chambers is essential to optimize the training processes of aircrew members. Thus, the present study is aimed at analyzing the psychophysiological responses of aircrew members in an incremental hypoxia training protocol. Psychophysiological responses of 44 aircrew members (34 males and 10 females) in an incremental hypoxia training protocol (3 minutes at 0 meters, 8 minutes at 5,000 meters, and maximum time at 7500 meters) were measured. Results suggested that the incremental hypoxia training protocol did not affect cortical arousal and handgrip strength; however, it increased the sympathetic tone, perceived stress, perceived effort, and heart rate and decreased forced expiratory volume and blood oxygen saturation. Thus, we concluded that acute hypoxic hypobaric exposure leads to decreased parasympathetic tone, blood oxygen saturation, and maximal spirometry values, without negatively affecting handgrip strength and cortical arousal. This information will lead to find specific training systems that meet the real needs of aircrew.

Carbohydrate and Glutamine Supplementation Attenuates the Increase in Rating of Perceived Exertion during Intense Exercise in Hypoxia Similar to 4200 m.

The rating of perceived exertion (RPE) indicates the feeling of fatigue. However, hypoxia worsens the condition and can worsen RPE. We evaluated whether carbohydrate and glutamine supplementation alters RPE and physiological markers in running at 70% peak oxygen uptake until exhaustion in a simulated altitude of 4500 m. Nine volunteers underwent three running tests at 70% peak oxygen uptake until exhaustion: (1) hypoxia and placebo, (2) hypoxia and 8% maltodextrin, and (3) hypoxia after six days of glutamine supplementation (20 g/day) and 8% maltodextrin. The exercise and supplementation were randomized and double-blinded. Lactate, heart rate, haemoglobin O2 saturation (SpO2%), and RPE (6-20 scale) were analyzed at the 15th and 30th min. The level of significance was set at p ≤ 0.05. SpO2% decreased at the 15th and 30th minutes compared to resting in placebo, carbohydrate, and glutamine supplementation. RPE increased at the 30th minute compared to the 15th minute in placebo and carbohydrate supplementation; however, there was no difference in the glutamine supplementation condition. Heart rate and lactate increased after the 15th and 30th minutes compared to resting, similar to the three conditions studied. We conclude that previous supplementation with glutamine and carbohydrate during intense exercise in hypoxia similar to 4500 m can attenuate the increase in RPE by the increase in glycemia and can be a useful strategy for people who exercise in these conditions.

Acclimatization to Middle Attitude Hypoxia Masks the Symptoms of Experimental Posttraumatic Stress Disorder, but Does Not Affect Its Pathogenetic Mechanisms.

The effects of acclimatization to middle attitude hypoxia on the resistance to acute emotional stress were studied on the model of posttraumatic stress disorder in rats. Anxyolitic, but not anxiogenic effect was observed in acclimatized rats. However, acclimatized rats with posttraumatic stress disorder were characterized by hypofunction of the pituitary-adrenocortical axis, which is typical of this pathology, and reduction in corticosterone/dehydroepiandrosterone ratio. At the neuroendocrine level, up-regulation of glucocorticoid receptors and a decrease in the level of corticotropin-releasing hormone in the hippocampus were revealed. The observed modifications of regulatory mechanisms can underlie hypofunction of the pituitary-adrenocortical axis. It was concluded that acclimatization to middle attitude hypoxia masks behavioral symptoms of posttraumatic stress disorder, but does not alter its pathogenetic neuroendocrine mechanisms.

Cognitive Effects of Repeated Acute Exposure to Very High Altitude Among Altitude-Experienced Workers at 5050 m.

Background: We investigated altitude effects on different cognitive domains among perennial shift-workers at the Atacama Large Millimeter/submillimeter Array Observatory (5050 m), Chile. Materials and Methods: Twenty healthy male workers were recruited and assigned to either a moderate-altitude first (MAF group, Test 1: 2900 m and Test 2: 5050 m) or to a high-altitude first (HAF group, Test 1: 5050 m and Test 2: 2900 m). Test 1 was conducted at the beginning and Test 2 at the end of the shift-work week. Processing speed (RTI, reaction time), attention (AST, attention-switching task, and RVP, rapid visual processing), and executive function (OTS, One Touch Stockings of Cambridge) were assessed. Results: Of the three cognitive domains assessed, only processing speed showed altitude-at-test group interaction (RTI median five choice reaction time: F1, 17 = 6.980, [Formula: see text] = 0.291, p = 0.017). With acclimatization, there was a decrease in AST reaction latency mean (t17 = -2.155, dz = 1.086, p = 0.046), an increase in RVP accuracy (t17 = 2.733, dz = 1.398, p = 0.014), and a decrease in OTS mean latency first choice (t17 = -2.375, dz = 1.211, p = 0.03). Decreased variability in cognitive function was observed in AST reaction latency standard deviation (t17 = -2.524, dz = 1.282, p = 0.022) and in RVP response latency standard deviation (t17 = -2.35, dz = 1.177, p = 0.03) with acclimatization. At 5050 m of elevation, SpO2 was positively correlated with executive function in the MAF group (OTS problems solved on first choice: r(5) = 0.839, p = 0.018) and negatively correlated with executive function latency standard deviations in the HAF group (OTS latency to first choice standard deviation: r(10) = -0.618, p = 0.032). Conclusions: Our findings highlight the importance of acclimatization and improvement of blood oxygen level, even among high altitude-experienced workers, to optimize performance of cognitively demanding work and reduce high altitude-associated health risks.

Development of a Self-Administered Questionnaire to Detect Psychosis at High Altitude: The HAPSY Questionnaire.

Aims: Psychotic symptoms during exposure to high altitude (HA) have been linked to accidents or near accidents on the mountains. It is thus of great importance to directly identify psychotic symptoms in individuals who are exposed to HA quickly and reliably on the mountain, even in the absence of experienced medical personnel. Psychotic features at HA frequently include positive psychotic symptoms such as hallucinations, delusions, or disorganized thinking/speech. The aim of the current study was to develop the first self-administered questionnaire (High Altitude Psychosis [HAPSY] Questionnaire), which individuals may use in the future to self-assess altitude-related psychotic symptoms on the mountain. Methods: We utilized two existing self-rating questionnaires for psychotic symptoms (the Psychotomimetic States Inventory, PSI and the Cardiff Anomalous Perception Scale, CAPS) as the basis for a two-round Delphi process. As part of this process, additional statements were suggested by the 40 Delphi participants. Results: Eleven self-administered statements-all of them related to positive psychotic symptoms-were identified to be most useful for the self-detection of HA-related psychotic symptoms on the mountain. Conclusion: This is the first self-administered questionnaire that allows the identification of HA-related psychotic symptoms on the mountain. A subsequent validation study is needed to address the psychometric properties of this questionnaire. Clinical validation will have to be performed in a field study.

Going to Altitude with a Preexisting Psychiatric Condition.

Psychiatric disorders have a high lifetime prevalence affecting about 30% of the global population. Not much is known about high altitude (HA) sojourns in individuals living with a psychiatric condition. This lack of scientific evidence contrasts with the anticipated increase in numbers of individuals with preexisting psychiatric conditions seeking medical advice on HA exposure. Not only are there risks associated with a HA climb, but physical activity in general is known to improve symptoms of many psychiatric disorder and enhance measures of mental well-being like quality of life and resilience. There are additional positive effects of alpine environments on mental health beyond those of physical activity. All individuals going to HA with a preexisting psychiatric condition should be in a state of stable disease with no recent change in medication. Specific considerations and recommendations apply to individual psychiatric disorders. During the HA sojourn the challenge is to separate altitude-related symptoms such as insomnia from prodromal symptoms of the underlying disorder (e.g., depressive episode) or altitude-related hyperventilation from panic attacks. In case an individual with preexisting anxiety disorder decides to go to HA there might be a predisposition toward acute mountain sickness (AMS), but it should always be considered that many symptoms of anxiety and AMS overlap. Any medication that is anticipated to be taken during ascent or at HA should be tested for compatibility with the psychiatric condition and medication before the trip.

The Effect of an Expiratory Resistance Mask with Dead Space on Sleep, Acute Mountain Sickness, Cognition, and Ventilatory Acclimatization in Normobaric Hypoxia.

We examined the hypothesis that an expiratory resistance mask containing a small amount of dead space (ER/DS) would reduce the apnea-hypopnea index (AHI) during sleep, attenuate the severity of acute mountain sickness (AMS), and offset decrements in cognitive function compared with a sham mask. In a double-blinded, randomized, sham-controlled, crossover design, 19 volunteers were exposed to two nights of normobaric hypoxia (FIO2 = 0.125), using a ER/DS mask (3.5 mm restrictive expiratory orifice; 125 mL DS volume) and sham mask (zero-flow resistance; 50 mL DS volume). Cognitive function, AMS, and ventilatory acclimatization were assessed before and after the 12-hour normobaric hypoxia exposure. Polysomnography was conducted during sleep. AHI was reduced using the ER/DS sleep mask compared with the sham (30.1 ± 23.9 events·hr-1 vs. 58.9 ± 34.4 events·hr-1, respectively; p = 0.01). Likewise, oxygen desaturation index and headache severity were reduced (both p < 0.05). There were also benefits on limiting the hypoxia-induced reductions in select measures of reaction speed and attention (p < 0.05). Our study indicates that a simple noninvasive and portable ER/DS mask resulted in reductions (49%) in AHI, and reduced headache severity and aspects of cognitive decline. The field applications of this ER/DS mask should be investigated before recommendations can be made to support its benefit for travel to high altitude.

Impact of a 3-Day High-Altitude Trek on Xue Mountain (3886 m), Taiwan, on the Emotional States of Children: A Prospective Observational Study.

AIMS: Changes in emotions associated with mountain treks have rarely been reported. This study examined emotional state changes in sixth-grade elementary school students before and after a 3-day high-altitude mountain trek from the trailhead (2140 m) to Xue Mountain (3886 m) in Taiwan. METHODS: In June 2011, 201 students participated in the trek. The round-trip distance was 21.8 km. The age, gender, blood group, and family configuration of the participants were documented before the trek. A 36-item short-form survey instrument, including the Mood and Anxiety Symptom Questionnaire and the Positive and Negative Affect Scale for Children, was used to evaluate the participants' emotional states (happiness, anticipation, sadness, and anger). The participants answered the questionnaires 1 month before and 1 week after the trek. A Likert scale was used to evaluate individual items (range 1-4; from strongly disagree to strongly agree). We calculated scores for each index before and after the trek. The incidence and presentation of acute mountain sickness (AMS) among the participants was also studied and published previously. RESULTS: In total, 187 (112 boys and 75 girls) participants (mean age 11.9 ± 0.4 years) completed the trek and the survey. The sadness and anger scores (negative emotions) were significantly lower after than before the trek (39.5 vs. 36.6; p < 0.01). The happiness and anticipation scores (positive emotions) before and after the trek did not differ significantly (49.9 vs. 48.9; p = 0.11). No participant used AMS prophylaxis, while 78 participants met the AMS criteria. Negative emotions decreased more in those with AMS than without AMS (-4.6 vs. -1.8; p = 0.04), and the use of medications or acetazolamide did not alter the emotions. CONCLUSIONS: A 3-day high-altitude mountain trek can reduce children's negative emotions. Negative emotions decreased more in those with AMS, whereas medications or acetazolamide did not alter their emotions.

Psychophysiological response of different aircrew in normobaric hypoxia training.

Hypoxia remains the most important hazard in high altitude flights, but there is still a need for deeper analysis of the effect of hypoxia exposition in the psychophysiological and cognitive functions. The aim of this study was to study the effect of hypoxia training in cortical arousal, autonomic modulation, muscle strength and cognitive function. We analysed 23 male aircrew personnel of the Spanish Army and Air Force (10 Helicopter Pilots, 7 Transport Aircrew, 3 Transport Pilots and 3 F-18 Fighter Pilots) before, during and after a normobaric hypoxia exposition. Hypoxia produced an increase in perceived stress and effort, a higher Heart Rate and a decreased function of breath muscles. Working memory and pattern recognition were impaired after hypoxia exposition. Significant differences were found in cognitive tests performance among aircrew groups, suggesting differences on their previous training. These results can improve specific training for better preparation of pilots and aircrews for hypoxic threats. Practitioner summary: Distinct aircrew preparation produces a different hypoxia exposition effect on psychophysiological response and cognitive functions. Hypoxia produced an increase in Heart Rate, a decreased function of breath muscles, being more negatively affected in Transport Pilots. Cognition abilities were impaired after hypoxia exposition, independently of the aircrew group.

Hypobaric Hypoxia-Induced Learning and Memory Impairment: Elucidating the Role of Small Conductance Ca2+-Activated K+ Channels.

Hypobaric Hypoxia (HH) is well-known to cause cognitive impairment and synaptic dysfunction which results in neurodegeneration. Although the role of small conductance calcium-activated potassium channels (SK channels) has been reported in synaptic plasticity, cognition and different neurological disorders; however, the precise role of SK channels in HH-induced memory impairment remains yet to be explored. We, therefore, hypothesized the pivotal role of SK channels in HH-induced cognitive decline and investigated the SK channel expression during different duration of HH exposure (Control, 1, 3, 7 and 14 days) at mRNA and protein level in male Sprague-Dawley rats. Further the role of SK channels in spatial memory and neurodegeneration were explored by inhibiting SK channel through Apamin (a known SK channel blocker). Results from the present study revealed that acute exposure of HH for 3 days leads to significant increase in expression of SK1 and SK3 channels at mRNA and protein levels, which upon chronic exposure restored to normal. Remarkably, SK2 channel expression showed gradual increase from 3 days till 14 days. Immunohistochemical analysis revealed similar pattern in different regions of the hippocampus. Additionally, SK channel inhibition with Apamin prevented HH-induced neurodegeneration and memory impairment as evident from decreased number of Fluoro Jade-positive cells, pyknotic cells, and caspase-3 expression and improved performance in the Morris water maze task. Thus, the present study demonstrates that SK channels play a crucial role in HH-induced cognitive decline and neurodegeneration.

The relationship between anxiety and acute mountain sickness.

INTRODUCTION: Whilst the link between physical factors and risk of high altitude (HA)-related illness and acute mountain sickness (AMS) have been extensively explored, the influence of psychological factors has been less well examined. In this study we aimed to investigate the relationship between 'anxiety and AMS risk during a progressive ascent to very HA. METHODS: Eighty health adults were assessed at baseline (848m) and over 9 consecutive altitudes during a progressive trek to 5140m. HA-related symptoms (Lake Louise [LLS] and AMS-C Scores) and state anxiety (State-Trait-Anxiety-Score [STAI Y-1]) were examined at each altitude with trait anxiety (STAI Y-2) at baseline. RESULTS: The average age was 32.1 ± 8.3 years (67.5% men). STAI Y-1 scores fell from 848m to 3619m, before increasing to above baseline scores (848m) at ≥4072m (p = 0.01). STAI Y-1 scores correlated with LLS (r = 0.31; 0.24-0.3; P<0.0001) and AMS-C Scores (r = 0.29; 0.22-0.35; P<0.0001). There was significant main effect for sex (higher STAI Y-1 scores in women) and altitude with no sex-x-altitude interaction on STAI Y-1 Scores. Independent predictors of significant state anxiety included female sex, lower age, higher heart rate and increasing LLS and AMS-C scores (p<0.0001). A total of 38/80 subjects (47.5%) developed AMS which was mild in 20 (25%) and severe in 18 (22.5%). Baseline STAI Y-2 scores were an independent predictor of future severe AMS (B = 1.13; 1.009-1.28; p = 0.04; r2 = 0.23) and STAI Y-1 scores at HA independently predicted AMS and its severity. CONCLUSION: Trait anxiety at low altitude was an independent predictor of future severe AMS development at HA. State anxiety at HA was independently associated with AMS and its severity.

Suicide and High Altitude: An Integrative Review.

Reno, Elaine, Talia L. Brown, Marian E. Betz, Michael H. Allen, Lilian Hoffecker, Jeremy Reitinger, Robert Roach, and Benjamin Honigman. Suicide and high altitude: an integrative review. High Alt Med Biol 19:99-108, 2018. INTRODUCTION: Suicide rates are greater at high altitudes, and multiple mechanisms have been suggested for this relationship, including hypoxia, differences in population density, characteristics of suicide victims, and firearms ownership and access. To better understand these potential mechanisms, studies evaluating the associations between high altitude and suicide were examined. METHODS: A literature review of published studies on high altitude and suicide was conducted in Medline, Embase, Web of Science, the Cochrane Database of Systematic Reviews, and the Cochrane CENTRAL database. We extracted and analyzed all studies that met the inclusion criteria, excluding foreign language studies and letters. Most of the measurements and results were synthesized using modified Letts' criteria. RESULTS: Searches using an extensive list of keywords returned 470 articles, but only 6 met the inclusion criteria. The studies' samples ranged in size from 8871 to 596,704, while studies which did not document sample size reported suicide rates. In five of the studies selected, individuals living at high altitudes were at greater risk of suicide. Four studies used aggregated data at a county or state level to analyze variables, such as age, gender, race, socioeconomic factors, and firearms access. All the studies found that high altitude was independently associated with suicide. One study found that many individual characteristics of those who committed suicide were different at high altitudes than low altitude, including a lack of access or barriers to mental healthcare. Depression exacerbated by hypoxia was hypothesized as a possible biologic mechanism in three studies. CONCLUSION: These research studies published since 2009 support an association between high altitude and suicide rates at the state or county level, but do not provide sufficient data to estimate the effect of high altitude on an individuals' suicide risk. Although the impact of hypoxia on mood and depression has been hypothesized to be a contributing cause, many other individual factors likely play more important roles.

Performance, Mood, and Anxiety During a Climb of Mount Everest.

Karinen, Heikki M., and Martti T. Tuomisto. Performance, mood, and anxiety during a climb of Mount Everest. High Alt Med Biol. 18:400-410, 2017. BACKGROUND: Various studies have shown the deleterious effects of high-altitude hypoxia on visual, motor, somatosensory, cognitive, and emotional function and also in intelligence tests, reaction time, speech comprehension, hand steadiness, visual contrast discrimination, and word association tests. Because optimal cognitive abilities may be crucial for mountain climbers' safety, this study was intended to evaluate the changes in cognitive performance, mood, and anxiety during an Everest expedition lasting almost 3 months. METHODS: A set of physiological (Lake Louise score, oxygen saturation), cognitive (Colorado perceptual speed [CPS] test, number comparison [NC] test), and emotional measurements (Profile of Mood States, anxiety responses, psychological inflexibility) were collected from nine climbers on a partly unsupported Mount Everest expedition at various time points during the course of the expedition at Everest Base Camp (EBC). For confidence intervals we used 95% simultaneous Bonferroni corrected interval (BCI) for the differences. RESULTS: During this expedition, the estimates of trait anxiety decreased 13% toward the end of expedition after successful summiting (p = 0.004). Simultaneously, fatigue appeared to diminish and the CPS speed results improved 13%. Most expedition members suffered mild symptoms of acute mountain sickness during the first days in the EBC, but this did not affect the speed or the number of mistakes made in the CPS or NC tests. In CPS test the differences between pretest and the physically most demanding period (EBC4, BCI: 0.01, 4.43) and between EBC1 and EBC4 (BCI: 0.57, 4.99), between EBC2 and EBC4 (BCI: 0.45, 4.88), and between EBC3 and EBC4 (BCI: 1.12, 5.55) were significant, showing ever improving results during the expedition. CONCLUSION: The most important finding in this study was that well-motivated and trained, self-selected individuals, who volunteer for a long-duration mission, are capable of maintaining high levels of performance, steady mood state, and a good level of vigor on a Mount Everest expedition lasting nearly 3 months.

Findings of Cognitive Impairment at High Altitude: Relationships to Acetazolamide Use and Acute Mountain Sickness.

Phillips, Lara, Buddha Basnyat, Yuchiao Chang, Erik R. Swenson, and N. Stuart Harris. Findings of cognitive impairment at high altitude: relationships to acetazolamide use and acute mountain sickness. High Alt Med Biol. 18:121-127, 2017. OBJECTIVE: Acute mountain sickness (AMS) is defined by patient-reported symptoms using the Lake Louise Score (LLS), which provides limited insight into any possible underlying central nervous system (CNS) dysfunction. Some evidence suggests AMS might coexist with altered neural functioning. Cognitive impairment (CI) may go undetected unless a sensitive test is applied. Our hypothesis was that a standardized test for mild CI would provide an objective measure of CNS dysfunction, which may correlate with the symptoms of AMS and so provide a potential new tool to better characterize altitude-related CNS dysfunction. We compared a cognitive screening tool with the LLS to see if it correlated with CNS dysfunction. METHODS: Adult native English-speaking subjects visiting Himalayan Rescue Association aid stations in Nepal at 3520 m (11,548 ft) and 4550 m (14,927 ft) were recruited. Subjects were administered the LLS and a slightly modified version of the environmental Quick mild cognitive impairment screen (eQmci). Medication use for altitude illness was recorded. Scores were compared using the Spearman's correlation coefficient. Data also included medication use. RESULTS: Seventy-nine subjects were enrolled. A cut-off of three or greater was used for the LLS to diagnose AMS and 67 or less for the eQmci to diagnose CI. There were 22 (28%) subjects who met criteria for AMS and 17 (22%) subjects who met criteria for CI. There was a weak correlation (r2 = 0.06, p = 0.04) between eQmci score and LLS. In matched subjects with identical LLS, recent acetazolamide use was associated with significantly more CI. CONCLUSION: Field assessment of CI using a rapid standardized tool demonstrated that a substantial number of subjects were found to have mild CI following rapid ascent to 3520-4550 m (11,548-14,927 ft). The weak correlation between the LLS and eQmci suggests that AMS does not result in CI. Use of acetazolamide appears to be associated with CI at all levels of AMS severity.

Extensive Microhemorrhages of the Cerebellar Peduncles After High-Altitude Cerebral Edema.

Pichler Hefti, Jacqueline, Philipp Hoigné-Perret, and Raimund Kottke. Extensive microhemorrhages of the cerebellar peduncles after high-altitude cerebral edema. High Alt Med Biol. 18:182-184, 2017.-Neuromagnetic resonance imaging (MRI) of subjects who suffered from high-altitude cerebral edema (HACE) typically shows cerebral microhemorrhages (MH) of the corpus callosum, in particular the splenium, and supratentorial white matter. This is a case report of a 43-year-old male, who suffered from unusually prolonged severe ataxia and amnesia after having been rescued during the ascent to Mount Everest at 6400 m. MRI of the brain 63 days after the incident showed the typical MH in the corpus callosum, but, in addition, extensive MH were found in the middle cerebellar peduncles. These infratentorial MH might reflect the pronounced atactic gait disorder. This case describes the first HACE-associated MH in the cerebellar peduncles in a high-altitude mountaineer indicating a potential vulnerability of infratentorial brain areas to hypobaric hypoxia.

Physiological and psychological factors associated with onset of high-altitude headache in Chinese men upon acute high-altitude exposure at 3700 m.

Aim We aimed to identify clinical characteristics and risk factors associated with onset of high-altitude headache (HAH) after acute exposure at 3700 m. Method In two hours, 163 individuals ascended by plane to 3700 m. Demographic information, physiological and psychological measurements, cognitive function, physical work capacity tests and profile of mood states within one week prior to the departure and within 24 hours after arrival were examined. Results HAH patients featured significantly higher vertebral artery diastolic velocity (Vd), heart rate (HR) and pulmonary artery diameter. HAH was also associated with a more negative mood state, including scores for tension anxiety, depression, hostility, fatigue and confusion, as well as lower vigor (all p values <0.05). Furthermore, negative emotions were positively related to HAH severity. HAH slightly decreased cognitive functioning. HR, Vd, lack of vigor, confusion and self-reported anxiety (all p values <0.05) were independent risk factors for HAH. We have identified three independent baseline predictors for HAH including internal diameter of the left ventricle (LVD), Athens Insomnia Scale (AIS) and confusion score. Conclusions Higher HR, Vd, confusion and self-reported anxiety and insufficient vigor were independent risk factors for HAH. Furthermore, higher baseline LVD, AIS and confusion score are independent predictors of HAH.

Medication Use Among Mount Everest Climbers: Practice and Attitudes.

Luks, Andrew M., Colin Grissom, Luanne Freer, and Peter Hackett. Medication use among mount Everest climbers: practice and attitudes. High Alt Med Biol. 17:315-322, 2016.-The lay public, media, and medical experts have expressed concern about the ethics of climbers using medications to improve performance and increase the odds of summit success while climbing at high altitude, but the true incidence of this practice remains unclear. We conducted an anonymous survey of climbers who have attempted to climb Mt. Everest to gather information about medication use and attitudes toward medication and supplemental oxygen use while climbing the mountain. One hundred eighty-seven individuals completed the survey, providing information about medication and oxygen use for 262 expeditions to Mt. Everest between 1963 and 2015, the majority of which occurred after the year 2000. The majority of respondents were male (82%) and from English-speaking countries (75%). Medications were used on 43% of climbs, with acetazolamide being the most commonly used medication. Reported use of dexamethasone, nifedipine, sildenafil, or tadalafil was uncommon as was use of multiple medications at the same time. The majority of respondents indicated that it was acceptable for climbers to use medications and supplemental oxygen to prevent altitude illness while climbing Mt. Everest. Opinions were more mixed regarding whether summiting without the use of medications or oxygen carried the same value as reaching the summit using those interventions. Our data suggest that less than one-half of Mt. Everest climbers use medications during their expedition, with the primary medication used being acetazolamide, for prevention of altitude illness. Given the limitations of the study design and preliminary nature of these data, further research is warranted to further clarify these issues.