Pain and Suffering

Ronald Schleifer

• Publisher: Routledge
• Year: 2014
• Print ISBN: 9780415843263
• eBook ISBN: 9781135016012
• Topic: Social Sciences
• Subtopic: Sociology
• Index: Social Sciences

Pain is felt by everyone, yet understanding its nature is fragmented across myriad modes of thought. In this compact, yet thoroughly integrative account uniting medical science, psychology, and the humanities Ronald Schleifer offers a deep and complex understanding along with possible strategies of dealing with pain in its most overwhelming forms. A perfect addition to many courses in medicine, healthcare, counseling psychology, and social work.

Part IThe Nature of Pain

DOI: 10.4324/9780203757345-3

2 The Physiology of Pain: How the Body Works

DOI: 10.4324/9780203757345-4

We naively believed that pain is simple—it hurts or it doesn’t hurt—so there should be a single brain state we could see every time someone is in pain. But what we’ve stumbled into is the discovery that there’s a relative universe of hurt—that hurting is an immense, rich, and varied human experience, associated with an unknown number of possible brain states. From a scientific position, we’re overwhelmed at how large that universe is. We’re still at the stage where each step forward makes us realize how far we have to go.

—Dr. John Keltner, pain therapist (cited in Thernstrom 2010: 324)

Despite the fact that human beings have lived with pain from time immemorial, there remains a great deal of controversy concerning its nature and its meaning. Before the modern era, pain was understood across many cultures as a sign for something else: punishment, a message from the gods, a measure of payment, etc. In our own time, pain has been variously understood as simply a symptom for some other concomitant condition, a disease in its own right, a neurological subsystem comparable to other sensory systems such as sight or hearing, a psychological rather than a physical state, a physical rather than a psychological state, etc. Thus while there is great consensus concerning the cellular and, to a lesser extent, neurological physiology of pain in our time, there is also great controversy over the details of the physiology of pain and its place in the larger economy of human life. This chapter presents agreed-upon descriptions of the nature of the fact/event of pain; the following chapter examines areas of controversy concerning the physiology and meaning of pain in human life.

Figure 2.1 The Physiology of Pain

Definitions of Pain

In the last half century or so we have come to understand a great deal about pain as a physiological fact/event. Still, that physiological fact, as we shall see throughout this book, is strongly connected to the experiential phenomena of memory and anticipation—attention and expectation that are conditioned by schemas of experience—and more generally, as Dr. John Keltner says, with brain states associated with those experiential phenomena. In this, as noted in Chapter 1, the scientific study of pain has understood it as both a physiological fact/event and a phenomenological experience. (As already mentioned, phenomenology is the study of how the world is experienced rather than its nature outside of experience.) There is a neuro-physiological basis for this distinction of pain as a fact/event and as an experience, a distinction that is of the utmost importance in this book. That is, there is evidence for different neurological mechanisms for “procedural memory,” the memory of motor functions such as riding a bicycle, and “episodic memory,” the memory of specific events of experience such as a particular Sunday on which one rode in a bike race (see Donald 1991: 150–51, Ornstein 1997; Schleifer 2009: 142–45). This distinction suggests that pain exists as both an episodic memory—it is something that “happens” to a person—and it can also produce the seemingly simple fact of procedural or implicit memory, such as the automatic favoring of a limb or the tightening of back muscles even beyond the healing time of an injured disk. In this way pain is both an experienced event and a seeming automatic state of affairs. As suggested in Chapter 1 in the example of Hemingway’s story, physicians are often trained to overlook the experience/perception of pain in favor of the condition associated with it. Such training in large part takes acute pain as the model for all pain, and in so doing mistakes the nature of chronic pain and, sometimes, mistakes the nature of suffering. Not only does Hemingway’s doctor ignore his patient’s screams, he ignores any possible suffering it might give rise to in her family.

The International Association for the Study of Pain defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage”; and the IASP goes on to define it in some detail:

The inability to communicate verbally does not negate the possibility that an individual is experiencing pain and is in need of appropriate pain-relieving treatment. Pain is always subjective. Each individual learns the application of the word through experiences related to injury in early life. Biologists recognize that those stimuli which cause pain are liable to damage tissue. Accordingly, pain is that experience we associate with actual or potential tissue damage. It is unquestionably a sensation in a part or parts of the body, but it is also always unpleasant and therefore also an emotional experience. Experiences which resemble pain but are not unpleasant, e.g., pricking, should not be called pain. Unpleasant abnormal experiences (dysesthesias [an impairment of the senses, particularly touch]) may also be pain but are not necessarily so because, subjectively, they may not have the usual sensory qualities of pain. Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons. There is usually no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain, and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain. This definition avoids tying pain to the stimulus. Activity induced in the nociceptor [pain receptor nerves] and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state, even though we may well appreciate that pain most often has a proximate physical cause.

(IASP website)

As we shall see, there is some controversy whether this psychological/subjective definition of pain is correct. Thus, the philosopher Valerie Gray Hardcastle argues that the brain states that give rise to the experience of pain can better be described in neuro-physiological rather than psychological terms.

Patrick Wall, who (often along with Ronald Melzack) helped shape the study of pain in the mid-twentieth century, nicely describes the physiological fact of pain in a larger context. “Pain,” he proposes, “occurs as the brain is analysing the situation [that gave rise to pain] in terms of actions that might be appropriate” (1999: 169; see also 177); “pain,” he says, “is then best seen as a need state, like hunger and thirst, which are terminated by a consummatory act” (1999: 183). As a need state, pain is an experience that—like the experiences studied by the humanities—gives rise to action. The appropriate action pain provokes, however, unlike hunger and thirst, is not directed toward objects in the world (food or drink), but rather focuses on states of the body— the location of pain—and on brain states that give rise to the experience of pain.

In another definition, Dr. Scott Fishman, Chief of the Division of Pain Medicine, UC Davis, past President of the American Pain Foundation and past President of the American Academy of Pain Medicine, elaborates on Wall’s description. In an “incomplete understanding,” he writes (using the “alarm” metaphor he often repeats):

most of us think of pain as a sensation or a perception of a noxious stimulus. Pain is the alarm system in the human body that tells us about imminent harm, actual harm, or healing. The alarm system is connected to measurable biological and physiological responses that are associated with distinct molecules and cells in the body. However, that is not all that is involved in pain. Pain is a multidimensional phenomenon that integrates perception with emotion to form the complex experience of suffering. Although you can identify the precipitating event, the end result is like a symphony in which you are able to hear the themes but unable to distinguish all of the many instruments.

(2009: 132; see also 2000: esp. 5–51)

Pain, in this account, has three adaptive functions: to warn us of imminent harm (so that by “automatic reflex,” we remove our toes from a burning coal to avoid tissue damage [see Hardcastle 1999: 67–69 for a neuro-physiological description of reflex behavior]), to respond quickly to actual harm (so that we remove our burnt finger from a fire to prevent additional, irreparable tissue damage), and to promote healing (so that we “favor” injured parts of the body to evade exacerbation of the damage).

Others describe two rather than three functions: (1) the avoidance system and (2) the restorative or repair system (Grahek: 2001: 9). Studying asymbolia, a rare neurological condition where “patients feel pain upon harmful stimulation, but their pain no longer represents danger or threat to them” (2001: xii), Nikola Grahek suggests that the complex phenomenon of pain, which includes the perception of threat as well as physical sensation, cannot be understood as just simple (or “pure”) sensation. That is, he argues that asymbolia offers an example of:

the very essence of pain; that the pure juice of pain quality— the what-it-is-likeness of pain—has been extracted [from its affective and motivational aspects] and clearly presented. But … the pure juice or essence of pain experience thus extracted has turned out to be a blunt, fleshless, inert sensation pointing to nothing beyond itself, leaving no traces in the memory and powerless to move the body and mind in any way. Moreover, when reduced to pure sensation, pain becomes the object of ridicule.

(2001: 78)

As we see in these various (and somewhat controversial) definitions, there is much attention to the distinction between what Fishman calls the “sensation” and “perception” of pain: the combination in the event and experience of pain of more or less “objective” stimulation and more or less “subjective” perception. (Such stimulation, as suggested in Chapter 1, is often assumed to be passively received.) But despite this essential controversy related to pain, science—anatomy and more recently neurology—has nicely traced the physiology of these pain functions, and this chapter describes this tested and consensual knowledge.

As already mentioned in Chapter 1, the noxious phenomenon of pain—whatever its combination of sensation and perception—“is conscious by definition” (Glucklich 2001: 96). In fact, it has been noted by a pioneer in pain studies that “nothing can properly be called pain unless it can be consciously perceived as such (Livingston 1998: 141). Moreover, pain is literally and materially marked and inscribed in damaged tissue. That is, the memory of pain—like memory in general— has been shown to be a biological process in cellular mechanisms through which pain is physiologically and psychologically remembered. (We should also recall the strange phenomenon of “amnesiac” anesthesia mentioned in Chapter 1 where such memory is erased.) That is, pain itself stimulates cellular mechanisms that allow even brief noxious stimuli to persistently alter the material state of actual cells and thus the nervous system itself, which may lead to central sensitization within the dorsal horn of the spine, the brain stem, the brain, and perhaps even peripheral sensitization in pain-receptor nerves or “nociceptors” (physiological sites of pain stimuli described later in this chapter). In even primitive organisms external impressions are laid down within the body itself, leading to predispositions and tendencies to feel and react in a certain way (Hilts 1995: 28). The phrase “laid down” means that stimuliexperiences (here the combination of sensation and perception) are actually, materially marked in the body. In 2000 Eric Kandel won the Nobel Prize in Physiology or Medicine for his work on the mechanics of memory storage in neurons by focusing on a single sensory neuron and a single motor neuron of the giant invertebrate sea snail, aplysia. His research group found that “a shock to the tail activates modulatory interneurons that release serotonin, thereby strengthening the [synaptic] connections between sensory neurons and motor neurons” by creating the growth of new synaptic connections, “an anatomical change [involving] the synthesis of new protein” (2006: 254, 256). In other words, the ways in which noxious stimuli led to the physiological alteration of a neuron was demonstrated: neurons are materially transformed by new growth. The phenomena Kandel describes participate in a long-time understanding of pain—going back to René Descartes at the beginning of the Enlightenment in the seventeenth century—in relation to a model of stimulus and response: in pain, a noxious stimulus creates a physiological and affective (“feeling”) response, understood as an instance of the simple (i.e., passively one directional) stimulus-response model proposed by Descartes and later by mechanistic behaviorism in the early twentieth century. It is this understanding of pain that governs the physician’s response in Hemingway’s story, where pain doesn’t seem important once it fulfills its “alarm” function...

Table of contents

• Cover Page
• Half Title Page
• Title Page
• Copyright Page
• Table of Contents
• Series Foreword
• Preface and Acknowledgments
• Introduction
• Part I: The Nature of Pain
• Part II: Experiences of Pain
• Part III: Living with Pain
• Bibliography
• Index