A mild brain injury occurs when:
- Loss of consciousness is very brief, usually a few seconds or minutes
- Loss of consciousness does not have to occur—the person may be dazed or confused
- Testing or scans of the brain may appear normal
Symptoms of a Mild Brain Injury
A mild traumatic brain injury is diagnosed only when there is a change in the mental status at the time of injury (the person is dazed, confused, or loses consciousness). The change in mental status indicates that the person’s brain functioning has been altered (this is called a concussion).
Symptoms of a mild brain injury include:
- Sleep disturbance
- Sensitivity to noise or light
- Balance problems
- Decreased concentration and attention span
- Decreased speed of thinking
- Memory problems
- Depression and anxiety
- Emotional mood swings
Moderate Brain Injuries
A moderate brain injury occurs when:
- A loss of consciousness lasts from a few minutes to a few hours
- Confusion lasts from days to weeks
- Physical, cognitive, and/or behavioral impairments last for months or are permanent
A severe brain injury occurs when a prolonged unconscious state or coma lasts days, weeks, or months.
Severe Traumatic Brain Injuries
There are several different categories of a severe brain injury including:
Coma: Coma is a state of unconsciousness from which an individual cannot be awakened, in which the individual responds minimally or not at all to stimuli, and initiates no voluntary activities.
Vegetative State (VS): is a severe brain injury in which arousal is present, but the ability to interact with the environment is not; eye opening can be spontaneous or in response to stimulation; general responses to pain exist, such as increased heart rate, increased respiration, posturing, or sweating; sleep-wake cycles, respiratory functions, and digestive functions return.
Persistent Vegetative State (PVS): The same as a vegetative state.
Minimally Responsive State (MR): This is a severe traumatic brain injury in which a person is no longer in a coma or a Vegetative State. People in this state display primitive reflexes; inconsistent ability to follow simple commands; an awareness of environmental stimulation.
Akinetic Mutism: neurobehavioral condition that results when the dopaminergic pathways in the brain are damaged. This results in minimal amount of body movement; little or no spontaneous speech; speech which can be elicited (the person can answer a question if asked, does not voluntarily say anything); eye opening and visual tracking; infrequent and incomplete ability to follow commands; vigilance and agitation for Frontal Akinetic Mutism.
Locked In Syndrome: Locked in Syndrome is a rare neurological condition in which a person cannot physically move any part of the body except the eyes. The person is conscious and able to think. Vertical eye movements and eye blinking can be used to communicate with others and operate environmental controls.
Brain Death: Brain death results from a very severe injury to the brain. When brain death occurs, the brain shows no sign of functioning.