HOW OUR BRAIN ACTUALLY WORKS
Brains are far more complex machines than even the most sophisticated computer. We turn on our computer with a simple switch. The screen entertains us as it boots up and we start to check our email, linger on Facebook to catch up with friends, or read the latest headlines. Have you ever wondered what your brain is doing in the early morning as you awaken to your automatic coffeemaker brewing that first cup of joe?
The main part of our brain, the cerebrum, sits inside our skull and is attached to our spinal cord by the small, but critical, brain stem. Inside the brain stem is a small, but critical, group of nerve cells known as the Reticular Activating System (RAS) that send messages up into the brain, not only to wake us up, but also to keep us alert. We call this process arousal -- no, not that tingling that you get when you kiss the man or woman of your dreams, but stimulation that keeps you awake. But just being awake isn't enough.
We need an intact upper brain to be aware of ourselves and our surrounding environment. Awareness is a higher-level function that requires areas of the cerebrum to process the information we see and hear. A patient may have their eyes open and look like they're awake, but if the brain is severely damaged they may have no awareness of their surroundings. We call this a vegetative state.
On the other hand, people who are in a coma are not awake and have no awareness of themselves or their environment. You can talk to them, pinch them, show them pictures of their family -- they will not respond. However, these patients are not brain dead. This is the source of the confusion that leads to the sensational headlines and stories.
In 1976, Karen Ann Quinlan was in a vegetative state, but lived for nine more years after her ventilator was discontinued. Theresa Schiavo had been in a vegetative state for 15 years. After a protracted legal battle her husband was granted permission to withdraw her nutritional support and she died. Both young women, like the people in the headlines, were not brain dead. People in a vegetative state usually have extensive brain damage, but may blink their eyes and look around, breathe on their own, yawn, chew, and even withdraw their arms or legs to painful stimulation. They are not brain dead, and no one is going to take their organs.
WHAT, EXACTLY, IS BRAIN DEATH?
What is the difference between someone in a coma, who may or may not improve, and someone who is truly brain dead and may be a candidate to donate their organs? Brain death is the irreversible cessation of all functions of the entire brain, including the all-important brain stem that houses the RAS and the mechanism that controls our breathing. Dead is dead. Brain death isn't a different type of death, and patients who meet the criteria of brain death are legally dead.