Prolonged Space Travel Linked to Brain and Eye Abnormalities
Posted on March 14, 2012
Magnetic resonance imaging (MRI) of the eyes and brains of 27 astronauts who spent prolonged periods of time in space revealed optical abnormalities. The abnormalities are similar to those that can occur in intracranial hypertension of unknown cause, a potentially serious condition in which pressure builds within the skull. These abnormalities are in addition to bone mineral loss and muscle atrophy, which are some of the already known effects of zero gravity on astronauts.
A team of researchers performed MRIs and analyzed the data on the 27 astronauts, each of whom were exposed to microgravity, or zero gravity, for an average of 108 days while on space shuttle missions and/or the International Space Station (ISS). Eight of the 27 astronauts underwent a second MRI exam after a second space mission that lasted an average of 39 days.
Here are the findings among astronauts with more than 30 days of cumulative lifetime exposure to microgravity:
- Expansion of the cerebral spinal fluid space surrounding the optic nerve in nine of the 27 (33%) astronauts
- Flattening of the rear of the eyeball in six (22%)
- Bulging of the optic nerve in four (15%)
- Changes in the pituitary gland and its connection to the brain in three (11%) of the astronauts.
Analysis of the MRI data appears online in the journal Radiology.