A recent issue has been whether Terri Schiavo is suffering from dying of thirst. Even if we accept that she is in a “persistent vegetative state”, that does not answer the question– not in the slightest. Many if not all animals lack consciousness, yet they can feel pain. Could it be that Terri Schiavo can feel pleasure and pain just as much as any of the rest of us? Indeed, if she lacks higher brain functions, could it not be that lying on a bed being kept warm and healthy is enough to make her blissfully happy, but that being cold or hungry would hurt her even more than it would hurt those of us who can take our minds off it by conscious thought?
I haven’t seen good discussion of this. What seems to be the case is that Terri’s brain is functioning fine as far as keeping her body healthy, but that the biggest part of the brain, the cerebrum, is mostly inactive. She was nowhere near being brain-dead; on that, everyone agrees. Since the brainstem and midbrain control such things as body temperature and heartbeat, do they also control such things as pain? In that case, I would think that Terri feels pain, even if she cannot express it.
As an indication for why we can’t trust doctors or other experts in cases such as Terri Schiavo, see the horrifying Medpage article, “Schiavo Feels No Pain”, which makes the claim of its title.
Patients in a persistent vegetative state like Terri Schiavo are a subgroup who suffer severe anoxic brain injury and progress to a state of wakefulness without awareness.
It is judged to be permanent after three months if induced nontraumatically. After 3 months, recovery is rare and life expectancy is approximately 2 to 5 years.
Patients in a persistent vegetative state do not feel pain, nor do they “suffer, ” says Michael De Georgia, MD, head of the neurology-neurosurgery intensive care unit at the Cleveland Clinic Foundation here.
Pain, as well as suffering, requires consciousness, which is lacking in a person in a persistent vegetative state, says Dr. De Georgia.
“Certainly these patients don’t suffer,” he adds. “Suffering is really that whole emotional aspect of pain: fear, anxiety, panic surrounding pain. You have to have consciousness to experience these emotions. So just as a person in a persistent vegetative state can’t experience pain because of a lack of consciousness, they also don’t suffer.” …
Dr. De Georgia says that a patient in a persistent vegetative state can experience arousal, meaning that the patient’s eyes may be open and the patient may laugh, cry or appear to track someone who is in the room.
And that is what can be confusing for people, especially relatives, he says. “For example, a patient in persistent vegetative state will grasp your hand. In fact if you put anything into the patient’s hand, the hand will grasp it. But this is a very primitive reaction. A newborn baby will grasp your finger, but there is no consciousness.”
It is consciousness that determines whether one can “feel” pain in the sense that most people understand when they talk about feeling pain.
This doesn’t mean that a patient like Terri Schiavo won’t respond to pain stimulus – if you pinch her arm, she is like to flinch away. “That is called nociception,” De Georgia says. “Tissue is damaged by the pinch, this generates a response in a receptor, which sends an impulse along the peripheral nerves. This impulse travels to the thalamus, which directs the arm to withdraw,” he said. It is what is commonly called a reflex.
Pain, on the other hand, is the recognition of nociception by the nervous system, which sends the impulse to regions of the brain where consciousness exists. In the case of a severely brain injured person – one in a persistent vegetative state – those areas of consciousness have been destroyed, and as result “they don’t ‘feel’ pain.”
Dr. De Georgia says that a new-born baby cannot feel pain. He says that someone might flinch from torture, but not be in pain. He says that they can be pinched, their skin can react by sending a signal to the brain, and the brain can process that signal in the thalamus– a part of the midbrain which may well have been undamaged in Terri Schiavo (all the discussion has been of the cerebral cortex)– and the brain can direct other parts of the body to react, but that still doesn’t count as pain. It is only pain if the patient is conscious.
Thus, when a doctor says that something won’t hurt, don’t count on him meaning that agonizing nerve impulses won’t travel up to your brain and be registered there. He just means you won’t be able to complain about it.
I just found a distressing medical article which seems to be saying that vegetative patients do feel pain, and even react to it in their cerebral cortex, and even react to noises there, despite showing no outward signs of consciousness:
Author: Dana
Short Link: http://www.houseoffusion.com/lists.cfm/link=m:5:16519:151206
http://www.jsmf.org/meetings/2003/nov/LaureysANB2002.pdf
Acta neurol. belg., 2002, 102, 177-185
Our group was the first to study pain perception in persistent vegetative state patients (Laureys et al., 2002a). Using PET, we measured changes in regional cerebral blood flow during high intensity electrical stimulation of the median nerve at the wrist compared to rest in fifteen non-sedated patients and in fifteen healthy controls. Evoked potentials were recorded simultaneously. Brain glucose metabolism was also quantified in each patient. The stimuli were experienced as highly unpleasant to painful in controls. In patients, overall cerebral metabolism was 40% of normal values. Nevertheless, noxious somatosensory stimulation activated midbrain, contralateral thalamus and primary somatosensory cortex in each and every vegetative patient, even in the absence of detectable cortical evoked potentials. Secondary somatosensory, bilateral insular, posterior parietal and anterior cingulate cortices did not show activation in any patient.
Note that the “primary somatosensory cortex” is part of the cerebral cortex, so even though these patients were vegetative, some of their cortex did survive and react to pain. In fact, their brains, if not their faces, even reacted to noises:
Similarly, auditory stimulation (95 dB clicks) activated bilateral primary, but not associative, auditory cortices in vegetative patients (Laureys et al., 2000b). Functional connectivity assessment revealed that the auditory association cortex was ‘disconnected’ from posterior parietal cortex, anterior cingulate cortex and hippocampus (Laureys et al., 2000a). Thus, despite an altered resting metabolism, primary cortices still seem to activate during external stimulation in vegetative patients whereas hierarchically higher-order multimodal association areas do not. The observed cortical activation is isolated and dissociated from higher-order associative cortices, suggesting that the observed residual cortical processing in the vegetative state is insufficient to lead to integrative processes thought to be necessary to attain the normal level of awareness (Schiff et al., 2002).
So even though these people may not be able to think, they can feel. But who are we to say that they cannot think? By “thinking” it seems we mean that certain parts of their brains react which in healthy people react during the activity we call thinking. In these patients, those parts of the brain do nothing, but other parts– the ones which in healthy people are associated with feeling stimuli– do react.