MEDICAL ANIMATION TRANSCRIPT: A concussion is a brain injury resulting from a violent head impact or rapid head acceleration deceleration. The brain is a soft and pliable organ, and requires physical protection from the environment. The walls of the cranial cavity provide a hard external shield from outside impacts. Inside the cranium, the brain floats in and is surrounded by cerebrospinal fluid. Cerebrospinal fluid provides a protective cushion as everyday movements of the head gently jostle the brain. A violent impact or rapid acceleration deceleration of the head can cause the brain to rotate and strike the inside of the skull. This injury compresses the brain and sends shock waves rippling away from the point of impact. The impact force stretches or tears neuronal axons, resulting in a mild form of the traumatic brain injury called diffuse axonal shearing. This injury compromises normal brain function because it interrupts communication between neurons. Physical symptoms of concussion include headache, nausea, poor muscle coordination, dizziness, light sensitivity and blurred vision, ringing in the ears, and loss of consciousness. Cognitive and emotional symptoms include disorientation, confusion, amnesia, inability to focus and concentrate, irritability, and depression. Treatment for concussion depends on the severity and duration of symptoms. Mild concussions require plenty of rest, increased fluids, and close monitoring of symptoms for 24 to 48 hours. Although mild pain medication, such as acetaminophen or ibuprofen may be prescribed, alcohol and illegal drugs should be avoided. Severe concussions require immediate professional medical evaluation. In many cases, steroids are used to decrease swelling and inflammation in the brain. A CT scan or MRI of the brain may be needed to rule out gross internal damage or hemorrhages.