What happens to one in a locked in syndrome?

Most theologies give no perspective on persons who are in "locked-in syndrome", minimal conscious states and persistent vegetative syndrome. Due to my own experiences I've pondered and explored but i would like to know your opinions on a modern age problem, where people survive more traumatic incidents on the body but show no or minimal reaction to their environment, this state is life or death seems almost like a modern to pheonomna but has the topic actually been covered before in the history of Buddhism? If so, which sources please.