What are the rates of recovery from a coma and a PVS?
The recovery rate is very dependent upon the cause of the coma/PVS, whether the cause is reversible or not, the amount of damage to the brain, the region of the brain that is damaged, and the amount of time that the person is in a coma or a PVS. When the cause of a coma is corrected before permanent brain damage occurs, the coma generally reverses within days. However, when the death of large areas of the brain occurs, the outcome is generally grim. Dead brain tissue does not regenerate. Recovery from illnesses symptomatic of dead brain tissue (e.g. stroke) usually is a result of other brain tissue being trained to assume the functions of the lost tissue. If not enough brain tissue is left to take over the functions of the lost brain tissue, recovery will not occur. The longer the coma, the larger and more diffuse the area of damage, the older the person, the less are the chances of reversal of the coma and recovery of function. Since a PVS is a late stage outcome of causes of irrevers