Vegetative state is one of the variants of emerging from coma, when patients have no signs of consciousness and understanding what is going on around them. The causes of coma or vegetative state can be damages of various parts of the human brain.
Unfortunately, there are no clear prognoses on time of waking up from vegetative state and recovery of consciousness. Identification of new mechanisms of diagnosis should contribute to improvement of methods of vegetative state treatment.
According to statistical data, a certain part of patients does emerges from vegetative state. Some additional methods of examination are needed to increase the number of such patients.
It is very important to study the vegetative state, to understand the fundamental problems, associated with integrative and cognitive function of the brain, providing the recovery of consciousness after a severe brain injury.
There are many social-economic and legal aspects, associated with treatment of patients in a vegetative state. The solution to many of them can be quite difficult even for countries with developed rehabilitation infrastructure and social welfare.
Therefore, the development of methods to forecast the emergence from the vegetative state is still a very important task these days. Based on these methods, it is easy to detect patients for targeted treatment and patients to for common treatment.
Vegetative state definition
There is more than one definition of vegetative state, which can differ more or less in various countries of the world. In addition, legal consequences may vary and there is no legal clarity in some countries.
Vegetative state is different from coma and is characterized as both a severe dysfunction of the brain cortex and the lack of mental and cognitive activity.
Many people compare the vegetative state vs coma. But there are fundamental differences between them. In case of vegetative state, the sleep-wake cycles, function of the gastrointestinal tract, the heart rate and the blood pressure remain normal.
Persistent vegetative state – is a diagnosis, made in patients after 4 weeks of traumatic or non-traumatic brain injury. This term is also used to determine a state resulting the unsuccessful surgery.
Permanent vegetative state means that a person has been unconscious for several months since the moment of non-traumatic and about a year since traumatic brain injury.
There are some other definitions of the vegetative state in different countries of the world. The criteria for testing the diagnosis of the persistent and permanent vegetative state may differ significantly (for instance in the USA and UK).
The Australian specialists in the field of neurology offered to replace the term “persistent” and “permanent” vegetative state to the synonym – post-coma unresponsiveness. They believe that the new term describes these uncontrolled conditions better than the old ones.
Causes
Vegetative state may occur after a traumatic and non-traumatic brain injury. It is believed that car accidents (developed countries) are the most common causes of traumatic brain injury.
There are other common causes of the vegetative state of non-traumatic genesis, such as: cardiac arrest, respiratory arrest, cerebrovascular damage, heart attack, tumors, hemorrhage and bacterial infections in the brain. Clinical studies demonstrate that the vegetative state arises approximately in 5 minutes after a global cerebral ischemia.
Sometimes, the vegetative state occurs in degenerative and metabolic diseases, including the inherited ones. In fact, the vegetative state can be caused by Parkinson’s and Alzheimer’s disease. In this case, the brain damage can develop for months or even years.
Diagnosis
There are several systems allowing doctors to diagnose the symptoms of vegetative state more or less effectively. Glasgow Coma Scale (GCS) is one of the most effective and frequently used system. GCS is an objective and reliable way to estimate the state of the central nervous system.
GCS takes into account together or separately the motor response, the reaction of eyes and the ability to make sounds or to communicate. The interpretation of combination of these elements allows to assess the function of the cerebrovascular nerves and to determine which ones were damaged.
Other criteria of diagnosis of the vegetative state are:
- Presence of the chaotic alternation of sleep and wakefulness
- Absence of reaction to pain stimuli
- Swallowing or respiratory disorder
The vegetative state is to be diagnosed after a few comprehensive neurological examinations. The doctor, who supposed to diagnose this state, must be skilled enough and competent in assessment of the brain function.
Treatment
There are different methods of treatment, used in patients with the vegetative state. Unfortunately, the vegetative state treatment does not provide full recovery in each individual case, although it does provides a positive effect on the CNS.
First of all, it is necessary to stabilize a patient after the traumatic or non-traumatic brain injury. The rehabilitation therapy helps to restore or maintain the main functions of the body.
In case of severe trauma of the brain, a patient might need some extra surgery. The brain should get enough blood and oxygen.
Today, about 15 to 35 thousands of patients are diagnosed the vegetative state in the USA. Hospitals specialized on this kind of disease, are using stimulating, surgical, physiotherapeutic and pharmacological methods. There is hope that the new methods of treatment will reduce the number of people with vegetative state.