This is your brain. This is your brain at altitude.

Back-to-back summits and brain scans to complement high altitude neurological studies


This May, local mountaineer Mike Moniz successfully summited Mount Everest (29,029 feet) and Lhotse (27,940 feet) only 24 hours apart. After consecutively climbing the word’s tallest and fourth-tallest mountains with the International Mountain Guide (IMG) Classic team, Moniz headed for home with an extremely rare contribution. Extreme for his plan to gather millions of data points from the highest peaks on earth, and rare because he plans to keep all the data in his head.

In addition to completing personal mountaineering goals this climbing season, Moniz says he hopes to gain a deeper grasp of the impacts his mountain travels have had on his brain, and he is working with a team of brain scientists to study his brain.

Medical studies have found that high-altitude mountaineering may affect the structure of the human brain, but researchers continue to investigate the function of mountaineers’ brains at high altitude.

Climbers often describe their recovery as a delayed and lethargic thought process, clinically defined as bradypsychia.

“Climbers that I’ve spoken to experience almost a fog, like a fog of war, after being off the big mountain, and it’s typically transient,” Moniz says. “And I think it may come out over time here in studies — that a lot of the cognitive issues that climbers face are almost like a hangover from being at high altitude. It could take a couple of weeks or a month or so before you start to feel more crisp and articulate and capable of carrying on a coherent conversation.”

The concern is that each summit attempt causes a person to essentially kill areas of their brain. Is climbing mountains causing brain damage?

While the effect is common among high-altitude athletes, who, in severe cases, can experience hallucinations, the cause and extent of any lasting effects are not as well-known. Even with low oxygen and physical exertion virtually promising adverse health effects, a tribe of athletes makes its migration to Nepal every spring, willing to subject themselves to one of the most severe environments on earth. Moniz says he welcomed the physical challenge and joined the clans as they ventured to base camp. Given the potential health risks and recent medical studies, Moniz says he wondered whether he, too, would lose part of his mind on his ascent of the highest peaks on earth, or if previous research missed the crux of the issue.

An article by developmental neurologist R. Douglas Fields published in Scientific American in 2008 shared startling results from neurologist Nicholas Fayed and colleagues from Zaragoza, Spain, on the effects of high altitude and low oxygen on the human brain by stating that mountain climbing kills brain cells. Fayed and his team’s research set out to measure brain damage using magnetic resonance imaging (MRI) to discover whether irreversible lesions affected high-altitude mountaineers. MR imaging provided non-invasive, high-resolution structural imaging of the brain as the primary tool for this research. The study evaluated 35 climbers for potential effects on the brain, 12 professional and 23 amateur climbers, without the aid of supplemental oxygen.

The Scientific American review of their report indicated that all but one mountaineer sustained brain trauma. The most severe cases were observed in Everest climbers, but brain damage also occurred on lower peaks.

Fayed and his team had subdivided mountaineers into expeditionary groups that climbed Mount Everest (29,029 feet), Aconcagua (22,841 feet), Mont Blanc (15,774 feet), and Kilimanjaro (19,341 feet). Of the 12 professional climbers and one amateur in the Everest expeditionary group, 11 climbers’ MRIs indicated evidence of brain atrophy, a decrease in the size of the brain, and the enlargement of fluid spaces surrounding the brain vasculature. Eight climbers’ images were consistent with brain atrophy. Only the amateur’s image indicated brain lesions after suffering symptoms consistent with acute mountain sickness (AMS) and high altitude pulmonary edema (HAPE). One professional mountaineer’s image demonstrated normal MRI results with no atrophy or lesions.

The study did not record MR images before climbing, and tests focusing on brain function were not performed to check mental ability.

Considering that only amateurs showed evidence of irreversible lesions in the brain, the research suggested that a lack of proper acclimatization may effect negative changes in the brain.

But the study could not eliminate the chance that a lesion existed before climbers left sea level, however unlikely. The rest of the climbers, including many professionals, showed evidence of atrophy and enlargement of fluid spaces surrounding the brain vasculature compared to normal scans, but for Everest professionals, this was not necessarily a direct impact of the climbs performed during the study. And these symptoms and image results are not clear indicators of brain damage or killing brain cells.

Fayed and his team’s research confirmed that individuals without proper acclimatization face higher risk of physiological changes in the brain. Further, the atrophy and lesion effects decreased with decreasing elevation — possibly putting Colorado’s 14ers out of the danger zone with appropriate acclimatization. Lesions persisted three years after the study in four of the eight Aconcagua climbers, and all eight were amateurs. Nevertheless, many considered the results significant enough to sound an alarm within the mountaineering community that resonated across mountain ranges the world over — high altitude kills brain cells.

“It shows fairly terrifying results of scarring and cognitive impact on the brain due to high-altitude exposure,” Moniz says, “even on mountains like Kilamanjaro.”

But the study did not include baseline images that captured what trauma existed before the climb, instead comparing post-climb MRIs against a control of 20 “healthy” volunteers. The lack of preliminary data raised questions about possible preexisting conditions in amateur climbers’ brains, and tests were not performed to see whether climbers lost physical abilities, often evaluated using interviews and finger-tapping exercises.

The medical consensus on brain damage has yet to be established.

Inspired by previous studies and capitalizing on the advantages of access and the decreasing costs of high resolution neurological imaging, Moniz says he hopes to contribute an individual look at the effects of altitude on his own brain.

The amount of information that he will be able to gather on his trip — though only one example and done with supplemental oxygen — is quite large and may serve as a template for future studies.

Part of the problem is not with the picture taken, but with the camera itself.

In acute cases of trauma to the body and brain, MRI serves as the first level of investigation in reviewing the structural impact of events, including fractures, strokes and hemorrhaging, to assist medical professionals in determining a treatment plan. But an MRI alone does not indicate brain function. That imaging’s inability to determine mental ability leaves an open, unexplored aspect of the human brain.

So Moniz plans to use both MRI and secondary nuclear-imaging in the form of single photon emission computerized tomography (SPECT) to evaluate his brain’s structure and function both before and after climbing some of the world’s tallest peaks. That combination should help bring the picture into focus.

He’s teaming with Denver-based CereScan, a leading company for clinical nuclear imaging specialists performing SPECT readings that correlate known conditions to mild-to-moderate brain injuries. Their technology assesses 5 million to 7 million data points across 140 regions of the brain, using data on normal brain function to determine how their results compare to known conditions that might affect brain function.

By comparing these data points to known cases of confirmed damage to the function of the brain, their method reduces the uncertainty of whether brain damage actually occurred.

CereScan’s software has been used to evaluate NFL athletes, members of the U.S. Ski Team and participants in other potentially traumatic activities including hockey, rugby and cheerleading.

“I think we’ll have a really intriguing opportunity to see whether there is structural damage, whether the performance of my brain has been somehow impaired, and, of course, what a lot of people question is, you know — what happens?” Moniz says.

Dr. Theodore Henderson, who works with CereScan, estimated that a normal mountaineer should demonstrate the same effects in a SPECT scan before and after a high-altitude bid. That is, no significant change is expected in the functionality of the brain after high altitude and low oxygen exposure. If they do see a change, they expect decreased brain activity. Further research would be required to determine whether changes in brain activity were merely an adaptive response.

In the weeks leading to Moniz’s departure to Nepal, Moniz and CereScan performed both MRI and SPECT scans in their testing with even higher resolution MRI equipment than Fayed and colleagues. The team will also perform the same testing procedure shortly after Moniz’s return to Boulder.

“I suspect with my genetics and my physiology, assuming if I take the right amount of time and am cautious, I shouldn’t have many problems,” he says. “But you never know.”

Reaching out to fellow high technology colleague John Kelley, CEO of CereScan, Moniz used his own skills as chief executive of locally operated technology solutions firm Circadence to pitch his project to approach the brain from the functional perspective.

“I’ve known John Kelley for a while — having access to a broad database of different types of [cases] where they had hypoxic and toxic gas exposure and other types of traumatic brain injury,” Moniz says. “In most of the research that had been done in mountaineering [on the human brain], it all sort of surrounds structure, looking at it from an MRI perspective, but not really the function of the brain and how the brain was functioning post-summit exposure. I love science and biology, and thought this would be a great contribution.”

Seeing a potential health threat from one of his most enjoyable activities (one he especially enjoys with his teenage children, Matt and Kaylee, accomplished climbers themselves), Moniz says he recognized an opportunity to take a closer look at this high-altitude issue.

But in a recently completed prospective research study to evaluate the neurological effects on 49 climbers before and after ascending Denali (Mount McKinley, 20,328 feet), Peter Hackett, director of the Center for Altitude Medicine in Telluride, found very different results than Fayed and his colleagues. Hackett, who also serves as clinical director of the Altitude Research Center and clinical professor for the Department of Emergency Medicine at the University of Colorado Denver Health Sciences Center, and his team designed their own study to utilize MRI and neurocognitive tests, and used finger-tapping exercises to evaluate the speed and effectiveness of the brain’s responses to commands. Tests and MRIs were done the week before and the week after returning from the expedition.

Their research found abnormal brain scans in only three of 49 climbers (approximately 6 percent), and they observed this effect as increased white matter volume and subcortical lesions. The negative impacts to climbers were significantly lower than Fayed’s research, with the additional contribution of prospective, before and after, neurocognitive data. And the three climbers who had abnormal brain scans experienced symptoms consistent with acute mountain sickness — their bodies hadn’t properly acclimatized. But no significant neurocognitive impacts were observed using finger-tapping exercises.

So, while time at high altitude presents risks to brain physiology, especially without proper acclimatization, the larger sample size of mountaineers, even those whose brains were modified by the time up high, returned functional.

Hackett shared his thoughts regarding Moniz’s efforts: “To really make it thorough, he should have neurocognitive testing as well,” Hackett says. This way, Moniz’s data would compare to previous studies. “Because if he does have brain changes, you want to know if it makes any difference. … Just because there might be changes in metabolism doesn’t mean it’s necessarily a bad thing. Maybe, if it’s an adaptive response, it’s a good thing.”

If there’s anything to take away from all the brain research out there, it’s not to stop — mountaineering has always had risks — but to be aware, as always.

With the hope to learn that high altitude does not compromise the mountaineer’s brain and mind, Moniz is on a route that sets a high, private standard by owning his personal health and exploring new technologies for medical research in the mountaineering community. All in hopes that further research holds implications for those up high and closer to earth.

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