Gu Jianwen, Wang Tao, Shi Tiejun, Li Nan, Luo Weiwei, Yang Yuan, Gao Junfeng, Gao Chuan, Strategic Support Force Characteristic Medical Center, Neurosurgery, Research Department, Medical Engineering Department, Aerospace Clinical Medicine Department, Manned Space Medical Team
New research from Oregon Health and Science University (OHSU) and scientists across the U.S. in 2022 shows that prolonged space flights alter the fluid-filled space in the brain along veins and arteries. The study will be published in Scientific Reports on May 5 local time.
Juan Piantino, lead author of the study, said: "These discoveries are significant as we continue to explore space. It also forces us to think about some fundamental questions of science and how life on Earth evolved. The study targeted 15 long-serving astronauts on the International Space Station to image their brains before and after their service. The researchers used magnetic resonance imaging to measure the space around blood vessels in the astronauts' brains before launch and immediately after their return, and again at 1, 3, and 6 months after return. Subsequently, images of astronauts were compared to the same perivascular space in the brains of 16 control subjects on Earth.
It was found that astronauts on their first space mission had an increase in the perivascular space in their brains, while experienced astronauts who had served on a space station in Earth orbit showed no difference. "Experienced astronauts may have reached some equilibrium. Piantino said. In all cases, the scientists found no problems with balance or visual memory, which may indicate that there were no neurological deficits among the astronauts, although there were differences in measurements of the space around the blood vessels in their brains. The study was the first to compare important aspects of brain health in space when comparing a large group of unidentified astronauts. The brain in space Human physiology is based on the evolution of life over millions of years while being bound by Earth's gravity. No longer constrained by gravity, the normal flow of cerebrospinal fluid in the brain is altered in space.
"We've all adapted to using gravity in our favor," Piantino notes. Nature does not put our brains under our feet, but on high places. Once gravity is removed, what will be the impact on human physiology?" The researchers decided to find out by measuring the space around the blood vessels where cerebrospinal fluid flows through the brain. These spaces are known to be part of the brain's natural cleansing system during sleep, and the entire brain network known as the colloidal lymphatic system removes metabolic proteins that build up in the brain. Scientists say the system works best during deep sleep. The measured perivascular space in the brain is equivalent to the basic "hardware" of the drinking system. The enlargement of these spaces occurs during aging and is associated with the development of dementia. Piantino said the study is of great value in assisting in the diagnosis and treatment of diseases involving cerebrospinal fluid on Earth, such as hydrocephalus. "These findings will not only help to understand the fundamental changes that occur during space flight, but also for people on Earth who suffer from diseases that affect cerebrospinal fluid circulation. ”
The above findings are based on medium- to long-term flights, and if you calculate them over decades, there is a chance that they will have some impact. For example, long-term cerebral edema can cause changes in the body in many ways, and here are some possible scenarios:
Long-term cerebral edema can cause lasting damage to brain tissue. Edema causes swelling of brain tissue, increasing pressure within the skull, which in turn affects the normal function of neurons. This can lead to impaired nerve signaling, which can affect various nervous system functions such as perception, movement, cognition, etc. Increased intracranial pressure may compress the blood vessels in the brain and reduce cerebral blood flow. Reduced blood flow can lead to a lack of oxygen to brain tissue, further aggravating neuronal damage and potentially triggering a range of neurological symptoms such as headaches, dizziness, confusion, and more. Affects the metabolic function of the brain.
The metabolic activity of neurons requires an adequate blood supply and a normal cellular environment. Cerebral edema interferes with these processes, leading to impaired energy metabolism that affects the survival and function of neurons. Long-term cerebral edema may lead to structural changes in brain tissue. This may include neuronal death, glial cell proliferation, and damage to the white matter of the brain. These structural changes can further affect the function of the brain. Negative effects on neurocognitive function. Patients may have cognitive impairment, memory loss, and difficulty concentrating, which seriously affect their ability to perform daily life and work. May cause intracranial hypertension syndrome. It is a serious condition that can cause symptoms such as headaches, vomiting, visual impairment, and can even be life-threatening.
It may also increase the risk of seizures. Abnormal firing of neurons can lead to seizures, causing additional health problems for the patient. Long-term cerebral edema can have effects on other systems in the body. For example, the respiratory system may be affected, resulting in respiratory insufficiency. The patient's emotional and psychological state may also be affected. They may have emotional problems such as anxiety and depression. The key to the treatment of long-term cerebral edema is timely diagnosis and effective treatment. This may include controlling the cause, lowering intracranial pressure, improving blood circulation in the brain, and more. Early intervention can reduce the damage of cerebral edema and improve the prognosis of patients. In conclusion, long-term cerebral edema can have widespread and serious effects on the body, including brain tissue damage, nervous system dysfunction, structural changes, and effects on other systems. Prompt diagnosis and treatment are essential to reduce damage and improve patient outcomes.