A Fascinating Study With Real Significance for Brain-Injured Patients.

What goes on in the mind of a patient who, tragically, has suffered severe brain damage? The answer has eluded doctors and scientists for years, but a new research study may have taken us a small step closer. Its findings may have ramifications both for patients and their families and for the controversy surrounding the Terri Schindler-Schiavo case, as well as others who have experienced brain injuries.

In a small, unique experiment carried out by research physicians from Cornell and Columbia universities in New York and Georgetown University in Washington, two brain-injured patients showed remarkable evidence of a potential ability to hear and understand the voices of close family members, with a brain response indistinguishable from that of a normal, alert person. The results of the study were published in the latest issue of Neurology, the journal of the American Neurology Association.

The background to this study arises from the observation that after a catastrophic brain injury, patients left in a coma, or semi-comatose state, may retain different forms of hidden, preserved brain function. A patient who does not die from such an injury may eventually move out of intensive care onto a regular hospital ward, once he or she is able to breathe on his or her own.

But further neurological recovery may then stall. Those patients who, to the observer, show no obvious awareness of themselves or their environment will have their condition labeled with the term "persistent vegetative state" (PVS). They behave as if they are in a permanent state of sleep.

Some patients, however, eventually appear to be able to react and respond to those around them, even though they may do so only intermittently. This episodic lifting of unconsciousness is puzzling to doctors and therapists, and a source of both hope and frustration for loving family members. They ask very good, emotionally laden questions: "Can my husband hear me? Does my daughter recognize my voice, and understand anything I tell her?" The problem is, there are often no answers.

Our hands-on clinical neurological exam can only tell us so much. The exam can be extended by recording the pattern of electrical brain waves with an electroencephalogram (EEG). But what "thoughts," if any, do they represent?

Brain-imaging tests such as CT and MRI brain scans show the damaged areas in detail. But, the paper's authors point out, in patients with this higher level of function (termed the "minimally conscious") "wide differences in structural injury patterns are present in patients with behavioral evidence of consciousness." In other words, you just can't tell.