The Coma State

The Coma State

A coma is a profound or deep state of unconsciousness. The affected individual is alive but is not able to react or respond to life around him/her. Coma may occur as an expected progression or complication of an underlying illness, or as a result of an event such as head trauma.

Coma is a state of brain function. The human brain performs at different levels of consciousness. Each level does not have distinct boundaries, but rather, at one end blends into the level above it and at the other, blends into the level below it. At the highest level of performance the mind is perceived as alert, sharp, quick to respond to varying forms of input. Through a gentle phasing down, the brain may become progressively less responsive until, at the lowest level of function, the brain is in a state of coma. This represents the last state before death. This state most frequently occurs abruptly rather than in phases, usually followed by a progressive recovery.

The different shades of a color progress from extremely dark to so light that the color appears white. In this spectrum of shades, coma might be compared to the darkest shade where the color can still be distinguished before coming black. All the other shades represent lighter and lighter levels of consciousness to almost white, at which point the brain is in a state of full alertness.

Individuals in such a state have lost their thinking abilities and awareness of their surroundings, but retain non-cognitive function and normal sleep patterns. Even though those in a persistent vegetative state lose their higher brain functions, other key functions such as breathing and circulation remain relatively intact. Spontaneous movements may occur, and the eyes may open in response to external stimuli. They may even occasionally grimace, cry, or laugh. Although individuals in a persistent vegetative state may appear somewhat normal, they do not speak and they are unable to respond to commands.

The outcome for coma and persistent vegetative state depends on the cause, severity, and site of neurological damage. Individuals may emerge from coma with a combination of physical, intellectual, and psychological difficulties that need special attention. Recovery usually occurs gradually, with some acquiring more and more ability to respond. Some individuals never progress beyond very basic responses, but many recover full awareness.