Individual levels of a coma are measured by the Glasgow Coma Scale. This measures the patient’s ability to respond by means of their eyes opening, motor response and verbal response. The minimum number and least responsive is 3 and the maximum is 15.
When the head injury is so severe that the patient remains in a coma state for an extended period, but is able to breathe without mechanical assistance, this is called a permanent vegetative state.
The period of time that a person remains in a coma or unconscious is often directly relevant to the future risk of developing epilepsy.
The driver of the car lost control after being apparently blinded by the sun as he drove over the crest of a hill. Although the driver escaped unscathed, the man suffered a permanent brain injury. After lying in a coma for six weeks, the man was transferred to a rehabilitation centre where he remained for three months before being discharged into the care of his parents. After a short time at home, he secured a place at a specialist residential brain injury centre where he underwent intensive neuro-rehabilitation treatment for another 15 months before returning home.