Coma 

Coma is also to be distinguished from the permanent vegetative state which may follow it. This is a condition in which the individual has lost cognitive neurological function and awareness of the environment but does have noncognitive function and a preserved sleep-wake cycle. Spontaneous movements may occur and the eyes may open in response to external stimuli, but the patient doesn't speak or obey commands. Patients in a vegetative state may appear somewhat normal. They may occasionally grimace, cry, or laugh.

Likewise, coma isn't the same as brain death, which is the irreversible cessation of all brain activity. One can be in a coma but still exhibit spontaneous respiration; one who is brain-dead by definition cannot do so.

The outcome for coma and vegetative state depends on the cause and on the location, severity, and extent of neurological damage: outcomes range from recovery to death. People may emerge from a coma with a combination of physical, intellectual, and psychological difficulties that need special attention. Recovery usually occurs gradually, with patients acquiring more and more ability to respond. Some patients never progress beyond very basic responses, but many recover full awareness.

A coma proper rarely lasts more than 2 to 4 weeks. Some patients who have gone into vegetative state may go on to regain a degree of awareness. Others may remain in a vegetative state for years or even decades. The most common cause of death for a person in a vegetative state is infection such as pneumonia.

There have been controversies and legal cases over whether to keep comatose patients alive for long periods using life support equipment[?].

A temporary coma is sometimes deliberately induced (using drugs) to reduce swelling of the brain after injury.

The Glasgow Coma Scale is used to quantify the severity of a coma. There are three components to the score: Eye opening response, Verbal response, and Motor response.

• E1 = None; E2 = To pain; E3 = To speech; E4 = Spontaneous

• V1 = None; V2 = Incomprehensible; V3 = Inappropriate; V4 = Confused; V5 = Oriented

• M1 = None to pain; M2 = Extension to pain (decerebrate posturing); M3 = Flexion to pain (decorticate posturing); M4 = Withdrawal to pain; M5 = Purposeful movement/localized response to pain; M6 = Obeys commands.

A score of E4V5M6 indicates the normal state; a score of E1V1M1 indicates complete unresponsiveness.

External link

• Some of the information in this section is from the public domain resource provided by the National Institute of Neurological Diseases and Stroke[?] at http://www.ninds.nih.gov/health_and_medical/disorders/coma_doc.htm

In astronomy, a coma is the tail of a comet produced by vapor boiled off the comet as it nears the sun.

In optics, a coma is an optical aberration in an astronomical telescope which causes a V-shaped flare to the image of a star. About coma in an Newtonian telescope (http://www.opticalmechanics.com/about_coma.htm)

handkerchief, tore the scarf from his neck, and wound them around his his life; then, seizing it, he stood waiting for the bear.html">bear.html">bear.html">bear.html">bear to come on. face dripping, dripping sweat, his breath coming hard and laboured from man and the savage panting of the beast. Presently he felt exactly where question of minutes, perhaps seconds. Suddenly it occurred to him that might be safety. Yet again, in getting up, the bear might seize him, and knocking on a door.html">door.html">door somewhere, and the roaring rush of the bear upon him. went in and out again. There came voices from the outside; evidently his scent, like the animal's, was keen. He had taken off his coat, and bear it covered his own position. He swung aside once more and drove his of the shutters. He gathered himself together for the next assault. pulled himself up with a last effort. His legs would not support him; he opening of the door, and a voice--Vanne Castine's--calling to the bear. His heart seemed to give a leap, then slowly to roll over with a thud, the door and out to the hallway into the yard as Nic swung through the the window lay Ferrol, the broken bayonet still clutched in his right was beating, but the shirt and the waistcoat were dripping with blood the Manor Casimbault, talking to the Regimental Surgeon, as Christine, CHAPTER IX "Is he dead.html">dead? is he dead?" she asked distractedly. "I've just come from me at once!" She caught the Regimental Surgeon's arm. He looked down at her, over his answered: "Alive, alive, my dear. Bad rip in the shoulder--worn out--weak-- .

 On wordlookup.net  

All is still licensed under the GNU FDL.
It uses material from the wikipedia.