SARA MANAVIAN, NORCROSS, GEORGIA: Hi, I'm Sara Manavian from Norcross, Georgia, and I want to ask</s>CNN: Why do people get amnesia sometimes when they hit their heads?</s>DR. SANJAY GUPTA, CNN MEDICAL CORRESPONDENT: The causes of amnesia are only partly understood. Injury to the brain can produce memory loss of the events that occurred just before trauma, called retrograde amnesia, or just after trauma, called antigrade amnesia. Depending on the severity of the injury, most amnesia lasts for only minutes or hours and disappears without treatment. With severe brain injury, however, the amnesia can be permanent. The brain's mechanism for memory is located in many different parts of the brain. It involves many different systems in the brain. Because of this, virtually any type of brain injury can result in memory loss.
Why Do People Get Amnesia Sometimes When They Hit Their Heads?