Vegetative state

A vegetative state (VS) or post-coma unresponsiveness (PCU), is a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness. After four weeks in a vegetative state, the patient is classified as being in a persistent vegetative state (PVS). This diagnosis is classified as a permanent vegetative state some months (three in the US and six in the UK) after a non-traumatic brain injury or one year after a traumatic injury. The term unresponsive wakefulness syndrome may be alternatively used, as "vegetative state" has some negative connotations among the public. There are several definitions that vary by technical versus layman's usage. There are different legal implications in different countries. Per the British Royal College of Physicians of London, a persistent vegetative state is "a wakeful unconscious state that lasts longer than a few weeks is referred to as a persistent (or 'continuing') vegetative state". The vegetative state is a chronic or long-term condition. This condition differs from a coma: a coma is a state that lacks both awareness and wakefulness. Patients in a vegetative state may have awoken from a coma, but still have not regained awareness. In the vegetative state patients can open their eyelids occasionally and demonstrate sleep-wake cycles, but completely lack cognitive function. The vegetative state is also called a "coma vigil". The chances of regaining awareness diminish considerably as the time spent in the vegetative state increases. Persistent vegetative state is the standard usage (except in the UK) for a medical diagnosis, made after numerous neurological and other tests, that due to extensive and irreversible brain damage a patient is highly unlikely ever to achieve higher functions above a vegetative state. This diagnosis does not mean that a doctor has diagnosed improvement as impossible, but does open the possibility, in the US, for a judicial request to end life support.