Theories About Pain...
The Gate Control Theory
Two researchers called Melzack and Wall formulated this theory in the late 1960’s. This theory proposes that the brain has a dynamic influence on the perception of pain and is not simply a passive recipient of pain signals from the nerves. Their original theory postulated that a gating process in the spinal cord responded to signals descending from the brain by either opening to allow more pain signals to access the brain or closing to reduce pain signals reaching the brain.
They suggested that psychological factors were among those that could influence the sensory flow of pain signals. In fact there is a growing body of research evidence that supports the understanding that cognitive activity and emotional arousal such as patient concern about re-injury or heightened awareness of potential pain can amplify pain signals and through neural plasticity rewire brain circuitry. More recently Melzack (2001) has modified the original theory and proposed a neuromatrix model. This model has expanded the original understanding of a spinal gateway to include the wide network of neural loops involved in pain experience. The areas involved in this include structures such as the thalamus and hypothalamus, the limbic system and the cortex. A gate control understanding applies very well to the new understanding of the wide range of brain centres involved in pain perception.
The Triune Brain and physiological theories
Although not a 100% physiologically accurate, the triune brain theory does offer some illustrations helpful to pain management. According to this theory, it is useful to think of the brain as coming in three levels. The outermost level is the human brain; this is the centre for human logic, language, planning and much of consciousness as we know it. The middle part of the brain can be equated to the mammal brain. This part is often referred to as the “Emotional brain” because much of our emotional processing happens here. This is where our fear, pleasure and general emotions tend to originate. The innermost part of the brain or the brain stem is often associated with the reptilian brain and is the seat of basic life processes such as breathing, eating and instinctual processes such as the sexual drive.
The key to this theory is that our “human” brain does not fully process the deeper experiences on a non verbal level contained in the “mammalian” and “reptilian” brains. So the pain experience does not necessarily make sense to the human brain because it is a more primitive experience that cannot be explained by the “human” brain’s conceptual abilities. From an evolutionary perspective this makes sense. To language an idea takes time which in a situation of danger can make the difference between life and death. Supposing a dog is biting you on the leg, the pain experience is a biological signal designed to protect the organism from damage or harm. Instead of having to think about the need to move away from the pain source, we instinctively recoil and try and avoid the pain source.
According to this theory pain is designed at its best as a protective function. We respond automatically in ways that protect the body from potentially life threatening damage. This is wonderful when the origin of pain is external, but a source of real difficulty is when the danger is past and the pain signals continue for any one of a number of reasons. When the body automatically recoils from a source of pain, a number of instinctive processes are initiated. The autonomic nervous system triggers a number of reactions. Sensory perception is heightened, heart rate increases, blood flow to the body surface and the digestive system is reduced and increased to the large muscle groups. The adrenals release adrenalin and the liver releases glucose into the blood stream among a host of other changes. These changes in effect “supercharge” the body for the well known fight-flight response. The muscles are innervated for rapid action, short term perception of pain is bluntened and the body becomes able to respond at peak levels for short periods of time. This is helpful if we are being attacked by a dog but in the face of constant low grade stimulation from chronic pain the same processes continue without conscious ability to make any substantial difference to the continual trickle effect of the danger response. Over time the effect of these responses become an added physiological stressor because the body is not designed to cope with these responses for prolonged periods, even at reduced intensities.
While cognitive therapy points to the very real ability of negative cognitions to increase or decrease the effects of pain, the more physiologically based theories point to the underlying automated survival processes that happen regardless of the cognitions held by the pain sufferer. This would encourage the logical response of learning how to sooth the signals affecting the mammalian brain and the reptilian brain and which are more sensory based and less likely to respond to “positive self talk”. In effect the reality is not so much an either-or situation as both-and response including both a cognitive and a physiological set of responses because in each case neither offers more than a reduction of certain aspects of the pain experience.
While this is largely true in broad terms, the larger picture is much more sophisticated as is shown by the following quote.
“Common sense might predict a specialised pain centre in the brain, connecting, perhaps, with another bit that registers sensation in the affected area of the body. In fact, scans show there is no such thing as a pain centre. Pain springs mainly from the activation of areas associated with attention and emotion. Seeing what pain is, in terms of neurological activity, it becomes clear why we feel so much more when we are emotionally stressed and why we often don’t notice it – even when our bodies are quite badly injured – when more pressing things have captured out attention.”
P12, Mapping the Mind by Rita Carter (Phoenix books, 2000)
The use of functional brain imaging techniques have provided clear evidence of the involvement of a number of key brain areas in pain perception. These include the anterior cingulated cortex, anterior insular cortex, primary somatosensory cortex, secondary somatosensory cortex, a number of regions in the thalamus and even some areas in the premotor cortex that are normally linked to motor function (Casey 1999).
Pain experience has much more involved in it ranging from the influence of neurotransmitters such as serotonin to the influence of hormonal body steroids such as testosterone and the emotional influences of neuropeptides. In effect the entire body operates as a co-ordinated and integrated whole with each of the different systems inter relating and influencing the others. While anyone working in the health sciences would agree with this, when it comes to pain we sometimes still act as if we assume that pain is happening in isolation and we forget that the entire body is affected at different levels by the experience.
Why talk about pain theories?
The issue is simple really, many patients suffering from persistent pain have never had pain processes and effects explained to them. The reason is because it is possible to get really complicated in describing pain pathways, the effects of afferent A and C nerve channels, potassium ions and more on a molecular level. But this degree of detail is not necessary and is only likely to result in most patients leaving the conversation with glazed eyes and a deeper sense of confusion.
What is helpful is a clear and simple explanation, using stories and illustrations that demystify the pain experience and which explains what is happening in the body in a way that depathologises the experience. The continual experience of pain changes a person’s attitude to their body and the world around them over time. Initially the patient is hopeful of, and expects to recover, but then gradually comes to realize that they may not experience the healing they hope for. This leads to a graduated series of changes in their attitude to themselves and the world around them. Initially, it is a case of “I hate being like this”, then it’s a case of “I hate my body being like this”, and then it’s a small step to becoming “I hate myself for being like this”. In this final state it is easy to be pain focused and the dislike initially focused on the world can become turned inwards against their own body and experience dread of the slightest twinge of pain.
A simple and clear explanation of what is happening in the body during a pain flare, helps to re-establish a sense of perspective, an understanding of processes that can reduce the panic triggered by a sense of ‘being victim’ to this unknown force called pain. This understanding of the pain processes also helps the patient choose potential ways of reducing the pain or of better coping with the pain. To know and understand something, is to be able to reduce the sense of being victim to it and enables a sense of empowerment and choice. This is crucial in pain management because uncertainty and tension both lead to increased pain.
The experience of pain sufferers
We live in a culture in which a range of myths affect our daily life and perceptions. While we are used to some of these myths, such as the myth of the value of youth, others tend to be more insidious. For example, many of us assume that most pain can be cured, or at least reduced substantially. The reality is often different. Patients can do the round with a wide range of medical specialists who do their best but by definition those experiencing chronic pain are in pain that is not substantially helped by medication or other means.
This means that the chronic pain sufferer becomes increasingly desperate, frustrated and at times, angry with the health professionals trying to help. The medical specialists in turn try an increasingly stronger regime of medications in which it is hard to achieve a balance between pain relief, side effects, loss of quality of life and feeling like a zombie.
People experiencing high levels of pain tend to be isolated. They cannot accomplish the range of physical actions they have been able to do easily prior to their injury. Physically they do not have the energy to do as much as they could beforehand and at the same time find their ability to concentrate or sustain attention is severely reduced. They are distracted by their pain, often unable to be comfortable in any position. This means that they are often not able to socialise as much, avoid doing many activities they once found enjoyable and tend to keep to themselves. They are often bored and under stimulated.
People who experience high levels of pain are frequently irritable, easily frustrated, withdrawn and depressed. They may talk about their experiences because their pain is so centrally a part of their experience that they have little else to talk about. Others avoid talking about their experience at all, for fear of being labelled “whingers” or of alienating friends or family.
Many people suffering chronic pain describe how it changes them. They feel that they are not the person they once were. They have lost confidence and are often uncertain of themselves, are more fearful of taking risks, become more negative and pessimistic. This profile is not one that the pain sufferer especially likes or wants, but which they often feel they have no control over.
Problems with using existing Counselling approaches with Physical Conditions
Counselling in situations involving pain tends to be short term, the patient population is often very frustrated and feeling powerless to do much to reduce their pain experience. They have most likely already been referred to a variety of health professionals and will also most likely have had one or two bad experiences. The memory of these past interactions are brought into any new situation and foremost for many people is the concern that they are going to be told it is “all in their head” in a way that they understand to mean that they are imagining it or choosing their condition.
For a person suffering pain who is depressed, the issues are not only intrapsychic but also include uncertainties about their prognosis. They are understandably scared that they will gradually deteriorate over time. In any situation involving chronic pain, the fears and uncertainties experienced by the patient may be reality based and not simply due to a range of maladaptive cognitions. Issues for a chronic pain sufferer are often more to do with the here and now situations facing them than from personal issues from their past. This means talking through the problems is less likely to be helpful.
A client centred approach or an approach that encourages the patient to tell their story can become very frustrating to the patient, if it is continued as the central theme of counselling. The patient needs some sense of direction that will help them cope better with their pain condition. Continually talking about the problem or the difficulties their experience causes them, increases the pain awareness and can reinforce their sense of powerlessness. A danger is that counselling can end up going in circles without a clear sense of direction. With this approach the primary danger is in seeking to be understanding and supportive of the patient that they are helped to remain stuck and given the indirect message they are passive victims to their experience needing continual ongoing support. This can result in dependency problems.
A similar problem is if the counselling approach seeks to examine the influence of pre-injury life experiences on the pain experience. A person who has had a difficult life, in which they have struggled to cope with a range of stressors and have tended to become overwhelmed easily, will not have as many emotional resources to deal with a chronic pain condition. The danger here is two-fold in that the patient can unintentionally be given the message that their previous life is to blame for their pain and that it is “in their head”. It is suggested as a rule of thumb to provide some direct skills that will help the patient better understand their situation, normalize their experience in the here and now and improve their coping skills. Once this has been done, if time and opportunity permit then those factors in the patient’s life that have predisposed them to struggle more with their pain experience can be addressed. This way it is likely that a stronger alliance between therapist and patient can develop. It is important not to “psychologise” the experience of pain too much.
Cognitive approaches, while generally helpful, do tend to reduce the pain management interventions to relaxation, assertion training and reducing catastrophic thinking. More can be done by adopting a more holistic view that increases the patient’s understanding of their experience, teaches them strategies that can help reduce pain and which improves quality of life. The overly strong commitment to tools such as a pain diary can be counter productive because it can result in increasing the pain focus and awareness of pain. However, more recent advances in cognitive psychology under the lead of theorist Martin Seligman have huge implications for pain management counselling. These approaches fall under the general title of “Positive psychology” and adopt a strengths based approach that helps the patient develop a clear sense of the value of positive attributes such as optimism, kindness, generosity and other related qualities that have a definite “feel good” component.
It is important that approaches to pain counselling:
- Have an understanding of pain experience.
- Are supportive of the patient’s experience.
- Are practical and clear.
- Identify early in the process what could and could not be done to help.
- Present simple, straightforward and not overly complex interventions.
- Are focused on what can be done practically to help reduce the pain experience and “solution focused.”
- Involve the patient in the process of pain management.
- Encourage patient to take responsibility to change and adapt their lifestyle to suit their condition.
- Understand and value the importance of working across disciplines with other professionals involved with the case.