A state of unconsciousness and unresponsiveness to external stimuli (for example, pinching) or internal stimuli (such as a full bladder). Coma results from disturbance or damage to areas of the involved in conscious activity or maintenance of consciousness – in particular, parts of the cerebrum, upper parts of the brainstem, and central regions of the brain, especially the limbic system. There are varying depths of coma. Even people in deep comas may show some automatic responses, such as breathing unaided and blinking. If the lower brainstem is damaged, vital functions are impaired, and artificial ventilation and maintenance of the circulation are required. With medical care, a person may be kept alive for many years in a deep coma ( persistent vegetative state) provided the brainstem is still functioning. Complete irreversible loss of brainstem function leads to brain death.
Coma |
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