vegetative state


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Related to vegetative state: Minimally conscious state

Vegetative State

 

Definition

A coma-like state characterized by open eyes and the appearance of wakefulness is defined as vegetative.

Description

The vegetative state is a chronic or long-term condition. This condition differs from a persistent vegetative state (PVS, a state of coma that lacks both awareness and wakefulness) since patients have awakened from coma, but still have not regained awareness. In the vegetative state patients can open their eyelids occasionally and demonstrate sleep-wake cycles. They also completely lack cognitive function. The vegetative state is also called coma vigil.

Causes and symptoms

The vegetative state can be caused by:
  • cardiac arrest
  • prolonged and profound hypoglycemia (an abnormal and severe decrease in blood sugar)
  • carbon monoxide poisoning
  • head injury
  • brain hemorrhage
  • compression of the brainstem
  • tumors
  • bilateral hemispheric demyelination (a loss of nerve cells)
  • injury of the brain following infections (meningitis or encephalitis)
  • neurodegenerative diseases
  • anencephaly (an abnormality of the brain and skull)
  • diffuse nerve cell injury
Patients in a vegetative state apparently have functioning of a special area in the brain called the reticular activating system (RAS) responsible for sleep-wake cycles. The connections that integrate more complex abilities such as awareness are interrupted. Patients in the vegetative state can open and close eyes spontaneously. They may appear to track or follow objects with their eyes. Patients may chew and swallow food placed in the mouth. The vegetative patient does not respond to sound, hunger, or pain. Patients cannot obey verbal commands and lack local motor responses. Additionally these patients cannot talk in comprehendible terms and they may become noisy, restless, and hypermobile. These patients are in a state of arousal but completely lack awareness.

Diagnosis

Diagnosis of vegetative state depends on the primary cause of brain dysfunction. A comprehensive history and neurological examination, neuroimaging studies, and chemical analysis of the blood are essential. Additionally, special tests such as cerebrospinal fluid (CSF, the fluid that bathes and nourishes the brain and spinal cord) analysis and electroencephalography, (EEG analyzes the electrical activity within the brain) may be indicated to establish a diagnosis.

Treatment

Treatment is directed to presenting symptoms and patient needs. Patients require constant monitoring and assistance with feeding, hydration hygiene, assisted movement (to help prevent ulcers and blood clots in the legs), and elimination of waste products.

Alternative treatment

There is no known alternative treatment for vegetative patients.

Prognosis

The prognosis is generally poor and the condition can persist chronically.

Prevention

There is no known prevention since this state can occur as a result of unavoidable situations such as an accident, tumor, and bleeding or genetic abnormality.

Key terms

Cognitive — The ability (or lack of) to think, learn, and memorize.
Hypermobility — Increased movement of joints.

Resources

Books

Goetz, Christopher G., et al, editors. Textbook of Clinical Neurology. 1st ed. W. B. Saunders Company, 1999.
Goldman, Lee, et al. Cecil Textbook of Medicine. 21st ed. W. B. Saunders Company, 2000.
Miller, Ronald D., et al, editors. Anesthesia. 5th ed. Churchill Livingstone, Inc., 2000.

vegetative state

a clinical condition in which there is complete absence of awareness of the self and the environment, accompanied by sleep-wake cycles, but with either partial or complete preservation of hypothalamic and brainstem autonomic functions; may be transient or permanent. There are multiple causes, all involving the brain, including traumatic and nontraumatic injuries, metabolic and degenerative disorders, and congenital malformations.

vegetative state

Clinical medicine A state characterized by unresponsiveness to external stimuli Types Permanent VS, persistent VS

veg·e·ta·tive state

(vej'ĕ-tā-tiv stāt)
A clinical condition in which there is complete absence of awareness of the self and the environment, accompanied by sleep-wake cycles, but with either partial or complete preservation of hypothalamic and brainstem autonomic functions; may be transient or permanent. There are multiple causes, all involving the brain, including traumatic and nontraumatic injuries, metabolic and degenerative disorders, and congenital malformations.

vegetative state

See PERSISTENT VEGETATIVE STATE.
References in periodicals archive ?
Some disabled activists seem actually to identify with people in persistent vegetative states. Given the history of eugenics during the 20th century, I can't blame them.
The determination of whether someone is in a persistent vegetative state is not an exact science--a British study in the mid 1990s found that 43 percent of a group of patients diagnosed as PVS (17 out of 40 studied) were misdiagnosed (later found to be alert and able to communicate).
The pope, who made the statement March 20 following a Vatican symposium on scientific and ethical issues surrounding people in vegetative states, also said families of vegetative patients need more emotional and economic support so they can better care for their loved ones.
Rory Rogers with his fiance Stacey Mckeowen before the assault which >left him in a persistent vegetative state Wales News Service
The team involved was the same that famously used imaging techniques to establish that a person in a vegetative state could respond to yes and no questions through their brain activity.
These strong connections, along with evidence from vegetative state patients, make the thalamus a prime suspect in the hunt for the seat of consciousness.
SIMPLE brainwave measurements can detect awareness in people who appear to be in a vegetative state, research has shown.
Aruna Shanbaug will live but landmark order clears way for legal euthanasia for those in passive vegetative state
Eluana Englaro, who is in a persistent vegetative state, was moved from a Catholic clinic to a private hospital inUdine on Monday night, said her family's lawyer.
Ms Rehbein asks, "Is the soul of someone identified as being in a persistent vegetative state not possibly in communication with God?" I believe the key word in this question is "communication." Since the soul's condition is established by our conscious decisions, I find it hard to believe it can be changed while a person is in a vegetative state except through the mercy of God, and I cannot believe that God's mercy is dependent on the length of time a person persists in that state.
"First Question: Is the administration of food and water (whether by natural or artificial means) to a patient in a 'vegetative state' morally obligatory except when they cannot be assimilated by the patient's body or cannot be administered to the patient without causing significant physical discomfort?
A husband is demanding an inquiry after the High Court ordered his wife, who was in a persistent vegetative state, be treated with an unproven drug against his wishes.