A coma is a state of unconsciousness lasting more than six hours in which a person: cannot be awakened; fails to respond normally to painful stimuli, light, or sound; lacks a normal sleep-wake cycle; and, does not initiate voluntary actions. A person in a state of coma is described as being comatose.
A comatose person exhibits a complete absence of wakefulness and is unable to consciously feel, speak, hear, or move. For a patient to maintain consciousness, two important neurological components must function. The first is the cerebral cortex—the gray matter that covers the outer layer of the brain. The other is a structure located in the brainstem, called reticular activating system (RAS). Injury to either or both of these components is sufficient to cause a patient to experience a coma. The cerebral cortex is a group of tight, dense, "gray matter" composed of the nuclei of the neurons whose axons then form the "white matter", and is responsible for perception, relay of the sensory input via the thalamic pathway, and many other neurological functions, including complex thinking.
A coma is a medical emergency. Swift action is needed to preserve life and brain function. Doctors normally order a battery of blood tests and a brain CT scan to try to determine what's causing the coma so that proper treatment can begin.
Comas seldom last longer than several weeks. People who are unconscious for a longer period of time may transition to a persistent vegetative state. Depending on the cause of coma, people who are in a persistent vegetative state for more than one year are extremely unlikely to awaken.
The signs and symptoms of coma commonly include:
- Open or closed eyes
- Depressed brainstem reflexes, such as pupils not responding to light
- No responses of limbs, except for basic reflex movements
- No response to painful stimuli, except for basic reflex movements
- Absence from RP's
- Irregular breathing
- Traumatic brain injuries
- Lack of oxygen
- Drugs and alcohol
- Wikia users ditching their role-play characters