People who experience a TBI often face memory loss, loss of cognitive abilities, difficulties with movement, and other challenges resulting from damage to the brain. The hormone progesterone has shown a great deal of promise in preventing death after TBI and in aiding recovery. Because TBI is a complex condition, researchers suspected that combination treatments that target multiple brain areas might offer the best chance for improving recovery.
Scientists funded by the National Center for Medical Rehabilitation Research tested combinations of progesterone and vitamin D hormone (VDH) after TBI in rats. They included VDH because studies have found that it, too, has a protective effect in the brain and that it might affect the activity of progesterone treatments after TBI.
The researchers found that rats who received progesterone combined with a low dose of VDH could remember how to navigate a water maze better than their counterparts, who received no treatment, progesterone only, or progesterone plus higher doses of VDH. The rats who had received this particular combination treatment were also more likely to venture out into the open water of the maze, rather than to hug the edges—indicating that this treatment reduced the amount of stress the rats felt in the maze. The researchers’ finding suggests that stress reduction from the treatment may have been responsible for the improvements in memory.
This study provides an additional piece of evidence that may ultimately contribute to an improved, combination-drug treatment for people with TBI (PMID: 22570859).