A severe traumatic brain injury (TBI) is characterized by an object that is lodged in the brain for over 24 hours, or if the victim has lost consciousness for over half an hour. This article deals primarily with cases in which there is a state of prolonged unconsciousness or a coma that lasts for days, weeks, or months.
A TBI can affect the responsiveness, alertness, awareness, consciousness, and arousal of a victim. Anoxic brain injury can also result in the victim entering a vegetative state. Following are abnormal states of consciousness that can result from brain damage:
Stupor – a state in which a patient is unresponsive but can be aroused briefly by a sharp pain or another strong stimulus
Coma – the patient cannot be aroused and is completely unconscious, unresponsive, and unaware. The patient does not respond to external stimuli and does not have sleep-wake cycles. Coma results from diffuse and widespread trauma to the brain and brainstem. It usually lasts a few days or weeks, after which the patient comes out of it, progresses to a vegetative state, or dies.
Vegetative state – the patient is unconscious and unaware of his or her surroundings, but can have periods of alertness and has a sleep-wake cycle. The patient will sometimes open his or her eyes and may groan, move, or have reflex responses. A vegetative state results from diffuse injury to the brain without damage to the brainstem. Anoxia can also induce a vegetative state. Many patients come out of a vegetative state within a few weeks.
Persistent vegetative state (PVS) - patients who do not emerge from a vegetative state within 30 days are considered to be in a PVS. The chances of recovery depend on the patient’s age and on the extent of the injury to the brain. Generally, children have a 60 percent chance and adults a 50 percent chance of recovering consciousness within the first six months. After a year, there is a low chance of regaining consciousness, and those who do regain consciousness will tend to have a significant disability.
Locked-in syndrome – the patient is awake and aware but has complete paralysis of the body. Most patients can communicate through movement or blinking of the eyes, or through a specialized device. Generally, only the brainstem and not the upper brain, is damaged. And while some patients can move certain facial muscles, most do not regain motor control.
Brain death – the patient has no measurable brain function. There is diffuse damage to the brainstem and to the cerebral hemispheres without any integrated activity between the brain’s distinctive areas. The condition is irreversible and removal of supportive devices results in immediate cardiac and respiratory arrest.
With advances in imaging and other technologies, it is now possible to differentiate between the various states of consciousness. MRIs and CT scans are commonly used in TBI treatment. But additional diagnostic and imaging techniques can now be used to confirm a particular diagnosis. These include:
- Cerebral angiography
- Electroencephalography (EEG)
- Transcranial Doppler ultrasound
- Single photon emission computed tomography (SPECT)
If you or a loved one has suffered a severe brain injury, please search our directory to find an experienced brain injury lawyer in your area.