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Biology 202, Spring 2005
Second Web Papers
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Levels of Awareness and the Damaged Human Brain

Catherine Barie

In recent weeks, the Terri Schiavo case has been at the front of national attention, highlighting the moral issues and legal implications accompanying the advancement of science and medicine. With new technologies comes a greater understanding of disease and injury and their physiological effects, and therefore, an increased capacity for care. But, this greater understanding is both a benefit and a curse: what is considered acceptable treatment and what is not? Where is the dividing line? The Terri Schiavo case thrust this dilemma to the forefront, forcing the nation to reach a decision, both medically and legally. During the legal "right-to-life" battle between her parents and her husband, the pivotal question was whether or not there was any possibility for recovery, or whether or not her life should continue to be sustained artificially. Despite the fact that Terri was biologically alive due to respiration and heartbeat, she was, in essence, cognitively dead because there was no discernable cortical activity.

Schiavo was a 41-year-old woman who suffered brain damage when a potassium deficiency caused heart failure, resulting in a cessation of the flow of oxygen-rich blood to the brain (4). This interruption of blood flow caused extensive brain damage, particularly to her cerebral cortex. Following her collapse, Schiavo lapsed into a coma, a state in which she remained for several weeks, until her eyes opened. This is relatively common for coma victims: "...they almost always emerge from this state in two to three weeks, doctors say, when the eyes open spontaneously. What follows is critical for the person's recovery. Those who are lucky, or who have less severe injuries, gradually awaken... The primitive brain stem, which controls sleep-wake cycles as well as reflexes, asserts itself first, as the eyes open. Ideally, areas of the cerebral cortex...soon follow...But in some cases – Ms. Schiavo's was one of them – the cortical areas fail to engage, and the patient's prognosis becomes dire" (1). Thus, the moments that immediately follow awakening from a coma are crucial; if the cerebral cortex "engages," then the patient will likely recover. But, if the cerebrum does not regain its higher functions, the chances of recovery are significantly reduced.

Following her awakening, Schiavo remained in an unchanging state. She was no longer comatose, but she wasn't conscious either. She exhibited signs of a sleep-wake cycle, and alleged response to stimuli. She was in a state of wakefulness, yet, there was no detectable cognitive awareness of events or conditions occurring in the surrounding environment. Doctors determined that she was in a persistent vegetative state (PVS): "Patients in a persistent vegetative state have severe brain damage and are in a state of 'wakefulness without awareness.' ...[They] are usually considered to be unconscious and unaware. They may experience sleep-wake cycles or be in a state of chronic wakefulness" (3). Schiavo's condition is consistent with that of a PVS. Patients in a PVS rarely improve, and so, after attempting numerous costly but nevertheless futile treatments, Terri's husband, Michael Schiavo, petitioned to have her feeding tube removed.

However, Terri's parents felt that she could possibly still recover. They argued that she was not in a PVS, but rather a minimally conscious state. People in minimally conscious states do eventually recover, in what is described as a slow return to consciousness. Individuals in a minimally conscious state show evidence of higher cognitive function. In 1987, a Texas doctor documented one such case: a teenager suffered brain damage during a car crash. She was in a coma for several weeks, and when she opened her eyes after a few weeks, she was initially unresponsive to external stimuli. After about15 months, the nurses caring for her noticed that she obeyed commands to close her eyes and move her leg. She continued to improve over time, and she eventually even learned to answer multiple-choice questions by blinking her eyes. After three years, she was consistently communicating by blinking her eyes (2). Thus, this patient showed evidence of cognitive function; she was able to answer questions and follow commands. Terri Schiavo, on the other hand, demonstrated no detectable cognitive function. While she did appear to smile and respond to a stimulus, it was not in a pattern consistent with being minimally conscious. These reactions were simply the result of the random firing of neurons. This response was not initiated by the I-function.
Moreover, Schiavo could not have been in a minimally conscious state due to the extensive damage of her brain. One neurologist who examined her in 2001, Dr. Ron Cranford, concluded that: "Schiavo's cerebral cortex had been completely destroyed and replaced by cerebrospinal fluid. The upper brain was about 80 percent destroyed, and there was also damage to the lower brain. The only part of the brain that remained intact was the brain stem, which controls involuntary functions such as breathing and heartbeat—allowing Schiavo to survive (with a feeding tube) even though she no longer had any cognitive function" (3). Thus, Schiavo could not have been in a minimally conscious state; the brain damage was much to extensive. Since her cerebrum was destroyed, she was incapable of higher cognitive function. Moreover, an EEG (electroencephalogram) of her brain showed almost no electrical activity, which would be present if her neurons were firing like those of a minimally conscious person (1).Therefore, Schiavo was in a PVS and not a minimally conscious state.

In conclusion, despite the fact that Terri was biologically alive (respiration and heartbeat), she was, in essence, cognitively dead because there was no discernable cognitive activity; she did not really respond to stimuli, and an EEG showed almost no electrical activity in her brain. The only reason why she wasn't labeled as brain dead was due to her functioning brain stem, which kept her heart beating and allowed her to breathe on her own. Why, then, was her case thrust to the forefront of national attention? This case basically illuminated and personified the moral issues that have accompanied advancements in science and medicine. These advancements have allowed or a greater understanding of illness and injury, and therefore contribute to a greater capacity for treatment. Individuals with conditions that were untreatable 100 years ago are now treated – they live much longer, and some even recover fully. But, this presents moral issues: it can be done, but should it be? Religion and medicine now appear to be locked in this struggle about what is or is not right. Basically, medicine and morality are "evolving" at different rates, so that ethics and morals are sometimes in conflict with medicine. Since the Schiavo case basically personified this struggle, it became the center of national attention. Even though a legal was made, some were unhappy with the decision. But, evolution is a slow and difficult process, and there will probably be more cases like this in the future.


1)Inside the Injured Brain, Many Kinds of Awareness

2)Coma, or Reduced Level of Awareness?

3)Terri Schiavo

4)Terri Schiavo Has Died

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