What is the difference between Closed-TBI and Open-TBI?

In closed-TBI, the skull and brain have not been penetrated by a foreign object. There may appear to be no injury. That’s one reason why the later effects of closed-TBIs are difficult to detect. In open-TBIs, there is an obvious breach of the skull and the brain, and hospitalization is required. Closed-TBIs are generally less severe than open-TBIs and account for the vast majority of TBI cases. Of the 1.7 million people who suffer a traumatic brain injury every year in the United States, 1.4 million people (82 percent) are treated and released by hospital emergency departments.