Early in my neurology training at
Massachusetts General Hospital, I was called to the emergency area to
see Mr. H., a 65-year-old who had collapsed at work. He was breathing
but totally unresponsive-not talking or responding to any of my
questions or commands. While I struggled to figure out what was going
on, one of Boston's great neurologists, C. Miller Fisher, entered the
room. Dr. Miller watched me for a few minutes before quietly addressing
Mr. H: "If you can hear me, raise your eyebrows." Much to my surprise,
Mr. H. did just that, raising both eyebrows. We immediately established a
communication system: raising his eyebrows once meant yes and twice
meant no. We were able to establish whether Mr. H. had any pain (he
didn't), knew where he was (he did), and aspects of his previous health.
Our conclusion was that Mr. H. had suffered a stroke involving his
brainstem and the outflow tracts from his cerebral cortex.
Dr. Fisher placed Mr. H. in a position
with his legs up and his head down and gave him medications to raise his
blood pressure. Mr. H.'s health gradually improved; two weeks later he
walked out of the hospital. He had been in a state that we now call
"locked in": He could not activate any outgoing systems (no movement of
his arms or legs, no speech, no response to a painful stimulus). All
that was preserved, initially, were slight movements of his eyes and the
area around them.
Mr. H. was on a continuum of altered states of consciousness, as described in the interview of Nicholas Schiff in American Scientist.
Dr. Schiff and his colleague, Dr. Joseph Fins, have done much to
clarify the various states of altered consciousness after severe injury
to the brain. The major effect of their work is to demonstrate that many
patients who were thought to be irreversibly brain damaged might have
residual activities that could be used to set up communication systems,
often long after the injury. As outlined in the interview, these two
have also been involved in the use of medications to improve functions.
Further approaches to restoring function are outlined in an excerpt from Stanislas Dehaene's book.
Dr. Dehaene describes the outcomes of patients similar to Mr. H. He
also postulates what may be going on in the brain and how it might be
measured. New ways of measuring brain activities are outlined in the Nature article, "Tuning the Brain."
This article is primarily about the use of deep brain stimulation in
Parkinson's disease. However, the new technique in question-the ability
to stimulate and record from the brain simultaneously-has direct
application to the study of unresponsive patients.
Thus, in today's world, we can take
images of these patients' brains to see what circuits may be responsive,
use deep brain stimulation both to record from and activate these
pathways, and devise and monitor appropriate therapies. When I was
getting started in neurology, all I had was a very astute mentor.