Coma

Often, alcohol is a contributing factor to injuries leading to an anatomic cause for comaCOMA : meaning deep sleep, state of unconsciousnessThere are several levels in COMA :
In the first level, the brain responsiveness lessens, normal reflexes are lost, the patient no longer responds to pain and cannot hear.A patient in a coma need not always lay still and quiet. They may talk, walk, and perform other functions that may sometimes appear to be conscious acts but are not, Comas generally last a few days to a few weeks, rarely more than 2 to 5 weeks. After this time, some patients gradually come out of the coma.People may emerge from a coma with a combination of physical, intellectual and psychological difficulties that need special attention
Coma can be caused by an underlying illness or by a head injury.Many people recover their full physical and mental functioning when they emerge from a coma. Some patients never recover anything but very basic body functions.Usually, coma is considered as an neurological emergency, and actions need to be taken quickly to avoid permanent damage.There are many metabolic causes of coma, including:A decrease in the delivery of oxygen, glucose, and sodium to the brain which are necessary for appropriate brain functioning. Drugs or alcohol in toxic quantities can result in neuronal dysfunction, Accumulated substances that might cause coma include ammonia due to liver disease, ketones due to uncontrolled diabetes, or carbon dioxide due to a severe asthma attack.The changes in chemical levels in the brain due to the electrical derangements caused by seizures.Coma is associated with loss of function in the arousal center in the brain stem which is responsible both for eye opening and for activating the cerebral cortex, which has to be functioning for a person to be aware of self and surroundings. Often coma is a resultant because of major structural discrepancies in various parts of the brain, like a severe head injury, brain hemorrhage, infection, tumor. If someone is in a coma, he is unconscious and will not respond to voices, other sounds, or any sort of activity going on around him. He is still alive, but his brain is functioning at its lowest stage of alertnessComas can be caused by different things, including: - a severe injury to the head that hurts the brain - Seizures - Infections involving the brain - Brain damage caused by a lack of oxygen for too long - An overdose of medicine or other drugs - A stroke People who wake and sleep but have no meaningful interaction with the world around them are said to be in PERSISTENT VEGETATIVE STATE. A person in a persistent vegetative state has damage to the cerebral hemispheres - the areas of the brain that govern sophisticated functions like consciousness, self-awareness and personality. There are many metabolic causes of coma, as already said, including decrease in quantities of substances like oxygen, sugar, and sodium. The changes in chemical levels in the brain due to the electrical derangements caused by seizures.COMA is different from brain death. When brain death occurs, there is no sign of any brain functioning. This condition is not reversible.