NASA astronauts have seen visual impairment intracranial pressure ( VIIP ) syndrome that might be related to the redistribution of body fluid to the head during long-term microgravity exposure. The exact cause of this, however, was unclear. Data Describing the adaptation of the human brain to microgravity was Insufficient, and it was Proposed That MRI Could be used to investigate the anatomy of the brain following spaceflight.
Donna Roberts, MUSC neuroradiologist conducted a study titled "Effects of Spaceflight on Astronaut Brain Structure as Indicated on MRI," and the findings will be published in the New England Journal of Medicine.
"Exposure to the space environment has permanent effects on humans." The experience of astronauts in space must be mitigated to produce space travel for the public, "said Roberts, an associate professor of radiology at MUSC.
The subtle anatomical changes in the brains of astronauts during spaceflight might contribute to the development of VIIP syndrome. In the current investigation, Roberts led a three-year NASA-funded bed rest study (from 2001-2004). The brains and muscular responses of participants who stayed in bed for 90 days were examined. The participants had to keep their heads continuously tilted in a downward position to simulate the effects of microgravity.
The brain's motor cortex before, during and after long-term bed rest was evaluated using the functional MRI. The results suggest that neuroplasticity in the brain occurred during the rest, and "crowding" at the vertex was prominent in the participants. Besides, brain shifting and narrowing of the space between the top of the brain and the inner table of the skull was also observed.
The brain MRI scans from the NASA's Lifetime Surveillance of Astronaut Health program for two groups of astronauts were also collected and compared. One group included 18 astronauts who had been in space for the shorter duration, and other group included 16 astronauts who had to be in space for a longer duration.
The cerebrospinal fluid (CSF) spaces at the top of the brain and CSF-filled structures were evaluated. The pre-flight and post-flight MRI cinema clips from high-resolution 3-D imaging of 12 astronauts from long-term flights and six astronauts from short-duration were also analyzed for brain structure.
The brain's central sulcus was narrowed in 94% of astronauts involved in long-term flights and 18.8% of the astronauts on short-duration flights. There was an upward shift in the brain and narrowing of the CSF spaces at the top of the brain between the long-term flight astronomers, significant changes in the brain structure were observed.
The findings were similar to idiopathic intracranial hypertension (IIH). CSF can be drained using a lumbar puncture to treat IIH, but there is no data to perform a lumbar puncture in a microgravity environment.
Michael Antonucci from Department of Radiology and Radiological Science mentioned, "This study is exciting in many ways, particularly as it lies at the intersection of two fascinating frontiers of human exploration – space and the brain."