Giving people with fresh traumatic brain injuries the hormone progesterone does no good, two major studies have found. The results dash some high hopes for treating a problem that affects millions each year, from combat troops to car crash victims.
Brain injuries account for more than 2 million hospitalizations or emergency room visits each year in the United States and often cause major disabilities. Roadside bombs have increased the number of troops suffering from the injuries, too.
Some drugs can reduce symptoms, such as swelling, but none are known to improve long-term recovery and prevent disability. Work in animals and two very encouraging small trials in people suggested progesterone might.
It is a female sex hormone that is thought to protect nerves and brain cells in a variety of ways, including curbing inflammation that causes swelling after an injury.
The two new studies were meant to be definitive tests.