PVS, or not PVS?

In the Hive and elsewhere, many are debating the propriety of letting Terri Schiavo starve to death. The latest to offer his position is a board-certified neurologist, Dr. William Cheshire Jr., in this affidavit.

This is not a gentleman given to wishful thinking:

There are many behaviors typical for patients in PVS that someone without neurological training could easily mistake as voluntary. The non-neurologist seldom has experience in obsreving how the brainstem and basal ganglia behave when deprived of input from the cerebral cortex where consciousness is believed to reside. It is quite common for dedicated and caring family members, hoping desperately for a sign from their loved one, to misinterpret these reflexes as evidence of communication. ... Some of the video clips of Terri Schiavo that have been presented in the media display such involuntary behaviors.

Yet he spends time going from there to ask some good questions:

It is my understanding that nearly three years have passed since Terri has had the benefit of neurologic consultation. How, then, are we to be certain about her current neurologic status?

...she has not, to my knowledge, undergone functional imaging studies, such as positron emission tomography (PET) or functional magnetic resonance imaging (fMRI).

New facts have come to light in the last few years that should be weighed in the neurologic assessment of Terri Schiavo. ...there is still a great deal we do not know about what previously-unsuspected cerebral cortex functions may yet be occurring in the minds of persons who have sustained profound brain damage and are no longer able to communicate outwardly...

He then gives six examples of already-existing behavior and incidents from her charts that "cast a reasonable doubt on the prior diagnosis of PVS." (His seventh example, which you can read for yourself, is admittedly non-scientific and speculative.) The fifth is especially damning, and seems to answer the question I asked just yesterday in debate over the topic.