Mild, Moderate, and Severe TBI
Traumatic brain injury severity is commonly described as mild, moderate, or severe. Injury severity is traditionally based on duration of loss of consciousness and/or coma rating scale or score, post-traumatic amnesia (PTA), and brain imaging results. Mild, moderate, and severe TBI may be characterized as follows:
- Mild TBI
- Brief loss of consciousness, usually a few seconds or minutes
- PTA for less than 1 hour of the TBI
- Normal brain imaging results
- Moderate TBI
- Loss of consciousness for 1 – 24 hours
- PTA for 1 – 24 hours of the TBI
- Abnormal brain imaging results
- Severe TBI
- Loss of consciousness or coma for more than 24 hours
- PTA for more than 24 hours of the TBI
- Abnormal brain imaging results
Severe TBI may be further sub-categorized as follows:
- Coma- a state of unconsciousness from which the individual cannot be awakened
- Vegetative State- a state in which an individual is not in a coma (i.e. awake) but is not aware of the environment
- Persistent Vegetative State- a vegetative state that has lasted for more than a month
- Minimally Responsive State- a state in which a person with a severe TBI is no longer in a coma or vegetative state and inconsistently interacts with/responds to the environment.
EXAMPLES of common cognitive-communicative, physical, and psychosocial/emotional consequences after mild, moderate, and severe TBI follow:
Mild TBI
- Cognitive-Communicative
- Decreased attention and concentration
- Decreased speed of processing
- Memory problems
- Getting lost or confused
- Decreased awareness and insight regarding difficulties
- Psychosocial/Emotional
- Irritability
- Depression and anxiety
- Emotional mood swings
- Physical
- Headache
- Fatigue
- Sleep disturbance
- Visual disturbance
- Dizziness
- Nausea
- Balance problems
Moderate and Severe TBI
- Cognitive-Communicative
- Decreased attention and concentration
- Distractibility
- Memory problems
- Decreased speed of processing
- Increased confusion
- Perseveration
- Impulsiveness
- Decreased interaction skills
- Decreased executive function abilities (for example, planning, organization, problem solving)
- Decreased awareness of, and insight regarding, difficulties
- Psychosocial/Emotional
- Dependent behaviors
- Apathy
- Decreased lack of motivation
- Irritability
- Acting out
- Depression
- Denial of difficulties
- Physical
- Difficulty speaking and being understood
- Physical paralysis/weakness/spasticity
- Difficulties with sense of touch, temperature, movement, position
- Chronic pain
- Decreased bowel and bladder control
- Sleep disorders
- Loss of stamina
- Appetite changes
- Partial or total loss of vision
- Weakness of eye muscles and/or double vision (diplopia)
- Blurred vision
- Problems judging distance
- Involuntary eye movements (nystagmus)
- Intolerance of light (photophobia)
- Decreased or loss of hearing
- Ringing in the ears (tinnitus)
- Increased sensitivity to sounds
- Loss or diminished sense of smell (anosmia)
- Loss or reduced sense of taste