New Neurologic Study: What is its Medical and Ethical Significance?
Read this science article in today's issue of the New York Times. It describes a study published in the current February 2005 issue of the journal Neurology. The study involved testing for metabolic brain activity using MRI imaging on two men who had traumatic brain injury and were in a "minimally conscious state"(MCS)(1) and comparing the responses to various stimuli with normal men and women. What was found was that there was evidence, on exposure to a recording of a familiar voice speaking, of patterns of metabolic activity in the temporal lobes of the traumatized patients that was similar to those of the normal subjects. By the anatomical location, the study suggested that there was active processing of language there possibly similar in some respects to normals. It is not clear what this all means but the New York Times article provides quotes from specialists who wonder if patients in MCS might be able to hear those who speak to them and may have some understanding though they may not be able to express what they hear. Also the experts wonder if this kind of MRI study technique may lead to more definitive diagnosis of the degree of neurologic impairment present beyond simple observation of behavior. The New York Times article relates the comments of the experts: " But they said the study did open a window on a world that has been neglected by medical inquiry. 'This is an extremely important work, for that reason alone,' said Dr. James Bernat, a professor of neurology at Dartmouth.
Dr. Bernat said findings from studies like these would be relevant to cases like that of Terri Schiavo, a Florida woman with brain damage who has been kept alive for years against her husband's wishes. In that case, which drew the attention of Gov. Jeb Bush and the Legislature, relatives of Ms. Schiavo disagreed about her condition, and a brain-imaging test - once it has been standardized - could help determine whether brain damage has extinguished awareness."
Unfortunately, it is not clear by the current research study whether the activity seen on MRI does tell, if any, how much and what quality of awareness is present.
In relation to the Schiavo case, a patient clinically disgnosed as in a permanent vegetative state (PVS)(2), the study did not involve PVS patients. Therefore what immediate consequences this report has on this case is unknown. However, since much of the significance of this study is unknown and there is no current treatment to reverse the anatomic and functional damage in PVS or MCS, it is my opinion that this will not change the ethical decision based on substituted judgment and supported by the courts in that case. ..Maurice.
1. Minimally Conscious States: Patients in minimally conscious states posses sleep-wake cycles and limited, inconsistent but definite awareness of self and environment (e.g., avoiding unpleasant stimuli, uttering intelligible sounds or reaching for objects in a way that adjusts for their size and location)
2.Vegetative States: The Multi-Society Task Force on Persistent Vegetative State (PVS), which included representatives from many of America’s most prestigious neurology associations, has defined the vegetative state as a condition of complete unawareness of self and environment, accompanied by sleep-wake cycles and either total or partial preservation of areas of the brain controlling automatic functions like heart activity and reflexes. PVS patients may cry or smile but these actions are reflexive and do not reflect true awareness.