Traumatic brain injury, concussion, post-concussion and chronic traumatic encephalopathy are all related. They all describe consequences of brain injury resulting from trauma, but there are some important differences between the 4 conditions.
Definition Of Traumatic Brain Injury (TBI)
TBI describes an injury to the brain that occurs as a result of a traumatic event. TBI may or may not cause neurological symptoms. TBI describes injuries to the brain such as bleeding, swelling and nerve damage. The injury may be large, requiring surgery, or it may only be microscopically small (mild TBI)
Definition Of A Concussion
A concussion describes temporary neurological symptoms or loss of brain function that occur as a result of a mild traumatic brain injury. Typically, a concussion describes a traumatic brain injury that does not cause visible bleeding, swelling or injury in the brain, characterized as mild TBI. There is no test that can detect microscopic brain injury, so a concussion is a diagnosis based on the symptoms (what the person experiences) and the signs (what the doctor finds on examination).
Symptoms And Signs Of Traumatic Brain Injury And Concussion
TBI does not always produce symptoms, but it usually causes symptoms of a concussion. Sometimes a concussion or TBI results in loss of consciousness immediately after the head injury. Often, a concussion or TBI causes immediate confusion. Many people experience amnesia (memory loss) of the events shortly before, during or after the head injury. The most common symptoms of TBI and concussion include headaches, sleepiness and trouble concentrating lasting between a few hours to a few weeks. Irritability is fairly common in the weeks after a concussion. And, unclear speech or even difficulty understanding words may occur although this is less common.
Severe TBI characterized by large amounts or bleeding or swelling, produces more severe and long lasting symptoms, such as vision loss, paralysis or seizures.
Diagnosis Of Traumatic Brain Injury And Concussion
A concussion or mild TBI, by definition, are not associated with major bleeding or extensive swelling in the brain. The diagnosis is based on a thorough neurological and neuropsychological examination. Sometimes, post-concussive testing is compared to baseline pre-concussive testing to assess any decline. Pre-concussive testing, which examines thinking skills and the speed and accuracy of responses, is becoming more commonplace in school sports. Student-athletes are often required to take pre-concussive tests, which serve as a source for comparison in case a head injury occurs during the sports season. However, most people who experience a head injury do not have a pre-concussive baseline test with which to compare.
If the neurological examination reveals problems such as weakness or vision changes that imply a major injury to the brain, a brain imaging test is performed to rule out a large area of swelling or bleeding that would require emergency medical or surgical care.
The diagnosis of a concussion means that the neurological problems are present, but there is no visible brain injury that is responsible for the symptoms.
Next: Post-concussion Syndrome, Chronic Traumatic Encephalopathy (CTE)