When the results of a head injury are worse than mild TBI or concussion, the injury may be classified as moderate or severe TBI. The factors used to define moderate TBI are:
- A loss of consciousness that lasts for more than 30 minutes but less than 24 hours
- Memory loss after the traumatic event, called post-traumatic amnesia or PTA, lasting for 24 hours to 7 days
- A Glasgow Coma Score of 9 – 12
Severe TBI is classified based on:
- A loss of consciousness that lasts for more than 24 hours
- PTA lasting for 7 days or longer
- A Glasgow Coma Score of 8 or less, which indicates that the patient is in a coma
There are also several factors that will help predict the level of recovery from a moderate to severe brain injury. Those factors include:
- how severe the injury is
- how fast and how well the body recovers
- the brain functions affected by the injury
- the areas of brain function that are not affected by the injury
- the age of the patient at the time of injury
- other injuries to the body from the same traumatic event
The long-term effects of moderate to severe TBI can include challenges with attention span and the ability to concentrate and remember. These are known as cognitive problems. Difficulties with processing input from the senses, such as touch, vision, hearing, taste and smell may also occur. Other effects can include, seizures, chronic pain, sleep disorders, loss of bladder or bowel control, and a variety of social and emotional challenges.
A severe traumatic brain injury involves an unconscious state or coma that lasts days, weeks, months, or even years. Typically, the greater the amount of brain damage, the longer a person remains in a coma, and the more challenging the recovery may be.
It’s important to keep in mind that every traumatic brain injury is different, and every person responds differently.