It is when a person is awake but shows no signs of consciousness.
Upon recovery from coma, VS / UWS is characterized by return of arousal without signs of consciousness. In contrast, a coma is a state that lacks awareness and wakefulness.
Lack of awareness can only be inferred from a lack of responsiveness to the environment and not from a lack of awareness that we cannot detect through behavioral measures.
For this reason, many authors have suggested that the term ‘Unresponsive wakefulness syndrome’ (UWS) (Laureys et al., 2010) or ‘post-coma unresponsiveness’ (NHMRC, 2004) are more accurate descriptive terms for the VS.
A person in a vegetative state may open their eyes, wake up and fall asleep at regular intervals and have basic reflexes, such as blinking when startled by a loud noise, or withdrawing their hand when it is clenched tightly.
They can also regulate their heartbeat and breathe without help.
However, a person in a vegetative state does not show any meaningful responses, such as following an object with their eyes or responding to voices. They also show no signs of experiencing emotions or cognitive function.
The eyes of VS / UWS patients can be in a relatively fixed position, can track moving objects (visual search), or move in a completely out of sync manner.
Sleep-wake cycles may resume or patients may appear to be in a chronic waking state.
They may grind their teeth, swallow, smile, shed tears, grunt, moan, or scream without any apparent external stimulus. VS / UWS patients do not respond to sound, hunger, or pain. Patients cannot obey verbal commands and lack local motor responses.
Additionally, VS / UWS patients cannot speak in understandable terms and can become noisy, restless, and hypermobile.
One of the most challenging tasks clinicians face is differentiating VS / UWS from minimally conscious states (MCS).
While neuroimaging, like MRI, is widely used to assess brain damage and functional abilities, behavioral assessment has, until now, been the ‘gold standard’ for detecting signs of consciousness and therefore for determining the diagnosis.
If a person is in a vegetative state for a long time, it can be considered to be:
- A continuous vegetative state: when more than four weeks have passed.
- A permanent vegetative state : when more than six months have passed if it was caused by a non-traumatic brain injury, or more than 12 months if it was caused by a traumatic brain injury.
If a person is diagnosed as being in a permanent vegetative state, recovery is extremely unlikely but not impossible.
Careful and ongoing evaluation of the patient, using empirically validated assessment tools (eg, the revised Coma Recovery Scale) is essential to assess and measure signs of progress, improvement, or deterioration.
The treatment is approached in the presentation of the symptoms and the needs of the patient; VS / UWS patients require constant monitoring and assistance with feeding, hydration, hygiene, assisted movement, and physical therapies (to help prevent leg ulcers and blood clots) and removal of waste products.
There is currently no treatment for VS / UWS that meets the efficacy criteria of evidence-based medicine. Pharmacological methods, surgery, physical therapy, and various stimulation techniques have been suggested.
Drug therapy mainly uses activating substances, such as tricyclic antidepressants or methylphenidate (Dolce et al. 2002). Surgical methods (eg, deep brain stimulation) are used infrequently due to the invasiveness of the procedures.
Stimulation techniques include sensory stimulation, sensory regulation, music and musicokinetic therapy, social-tactile interaction, etc.
Treatment cannot guarantee recovery from an altered state of consciousness, however supportive treatment is used to provide the best chance for natural improvement.
This may involve:
- Provide nutrition through a feeding tube.
- Make sure the person moves regularly so they don’t develop pressure sores.
- Gently exercise your joints to prevent them from becoming strained.
- Keep your skin clean.
- Control your bowel and bladder, for example, use a catheter to drain your bladder.
- Keep your teeth and mouth clean.
Efforts should be made to establish functional communication and environmental interaction whenever possible.
Offer opportunities for periods of meaningful activities, such as listening to music or watching television, showing pictures, or listening to family members talk.
- Visual : show photos of friends and family, or a favorite movie.
- Listen, speak, or play a favorite song.
- Smell : put flowers in the room or spray a favorite perfume.
- Touch: hold her hand or caress her skin with different fabrics.
Although they have not been empirically validated, families have reported the benefits of arousal regimens, such as those implemented by Dr. Ted Freeman (eg, Coma activation therapy).
This intensive therapy involves family members taking the patient through a controlled auditory, visual and physical stimulation regimen for up to six hours a day every day.
Forecast (prospects for recovery)
Many patients spontaneously emerge from VS / UWS within a few weeks. Some people gradually improve, while others remain in a deteriorated state of consciousness for years. Many people never regain consciousness.
Chances of recovery depend on the extent of the brain injury and age, and younger patients have a better chance of recovery than older patients.
In general, adults have about a 50 percent chance and children a 60 percent chance of regaining VS / UWS consciousness within the first 6 months in the event of a traumatic brain injury.
For non-traumatic injuries, such as strokes, the recovery rate drops during the first year.
After this period, the chances of the VS / UWS patient regaining consciousness are very low, and of the patients who do regain consciousness, the majority experience significant disability.
The longer a patient is in VS / UWS, the more severe the resulting disabilities will be.
Some patients who have entered a vegetative state continue to regain a certain degree of consciousness (see Minimally Conscious State). The probability of significant functional improvement for VS / UWS patients decreases with time.
There are only isolated cases of people regaining consciousness after several years. The few people who regain consciousness after this time often have severe disabilities caused by damage to their brain.