One Concussion Could Increase Risk of Parkinson's Disease, Study Says

A diagnosis of traumatic brain injury -- whether mild, moderate or severe -- is associated with an increased risk of developing Parkinson's disease as well as a two years younger age at diagnosis, new research in veterans says. The size of the risk was found to be dependent on the severity of the injury. After a mild injury, usually called a concussion, the increased risk was 56%, but moderate to severe injury raised the risk by 83%, according to the research, published Wednesday in Neurology, the medical journal of the American Academy of Neurology.