Different Categories and Causes of Pain and Pain Management Options

Interview with Mandy Collins and Phyllis Berger – Business Day Health Section (November 2009)


Mandy: I presume there must be different categories of pain beyond acute and chronic. What are the main kinds of pain that sufferers are likely to experience / What are the different causes of pain? 

Phyllis: Pain has the dubious distinction of being the commonest symptom for which a person approaches medical care. It is important to recognise that usually the acute pain situation is the first warning symptom that causes us to notice that we have a problem. It is necessary because as a result we take action to relieve ourselves either with known medication that usually helps or seek out the medical profession if the symptoms do not settle. We also may limit ourselves in movement by trying to keep still in order not to aggravate the condition. There are important aspects to this situation – it has now been discovered that severe, acute pain from whatever cause, that has been experienced for even less than twenty-four hours may develop into a chronic pain syndrome and the key to preventing chronic pain is to treat acute pain immediately. Also continuing to remain inactive as a protective mechanism may in some situations perpetuate pain due to lack of circulation and inactivity which creates weakness of muscles as in low back pain conditions.

Pain in itself is an entirely individual experience – “it is unique to an individual and is also perceived differently by each individual” writes M Jackson in her book Pain – the fifth vital sign. Pain is relayed via the nervous system which consists of the brain, spinal cord, autonomic nervous system, nerves that supply the musculoskeletal system, the internal viscera or organs of the body and the skin. If pain is very severe or continues for a protracted period it will activate and disturb a part of or the whole nervous system. Pain also affects the psyche and it may cause anxiety, fear, depression and even anger. In fact according to researchers Okifuji, Fernandez and Burns (2002) it is accepted that anger may precipitate, predispose an individual to pain, exacerbate pain, become a consequence of pain or even perpetuate pain. The most disturbing aspect of chronic pain is that it causes suffering!

Mandy: How are those different kinds of pain diagnosed? What are the different causes of pain? 

Phyllis: Pain today is usually analysed according to the mechanism that is involved. Trauma such as in an injury or a disease such as osteoarthritis may create damage to tissues that is painful and these tissues may then become inflamed – this type of pain is called nociceptive pain. This is due to stimulation of the nociceptors – sensory receptors sensitive to noxious stimulation in cutaneous (skin) or deep tissues. There may be swelling, compression of nerves, muscle spasm and decreased strength. Inflammation is usually due to a collection of inflammatory mediators – chemicals that are released by the body’s immune system that may increase pain such as substance P, bradykinin, prostaglandins, tumour necrosis factor, nerve growth factor, pro-inflammatory cytokines and others.

Another type of pain is neurogenic pain that may be generated by a nerve that is compressed such as in sciatica or even pain due to compression by a tumour which may affect nerves, blood vessels or tissues.

Pain that may persist long after an injury has healed may indicate some disturbance of the nervous system and this pain is referred to as neuropathic pain and serves no purpose to the individual whatsoever! Conduction of impulses in the nervous system is increased that may lead to continuous pain, stabbing, twingeing, shooting, electrical shocks, unpleasant tingling or sensations, unbearable touch, pain on movement of a joint, cold or hot/burning pain, painful numbness, disturbance of sleep and many other seemingly bizarre sensations – all due to the nervous system having become sensitised. This is due to a lack of inhibition from the brain and spinal cord or an over excitation anywhere along the neural pathway or nerves in the local tissues. There may also be inflammatory changes around these nerve areas. There may also be combinations of pain such as nociceptive and neuropathic pain – this may be present with an arthritic knee in which the knee may become sensitive to cold and touch and yet also have inflammatory pain which often disturbs sleep with pain during the night. Pain may also occur due to compression of the circulation and lack of oxygen in the tissues due to restriction of blood flow may also create severe pain – think of a tourniquet! Structural changes may also occur in neurons in the brain as a result of chronic pain and the areas involved are the hypothalamus and amygdala among others.

Mandy: What are the main kinds of pain that sufferers are likely to experience? 

Phyllis: Nociceptive pain is usually found in conditions such as trauma – injury to any musculoskeletal tissue such as fracture, sprain or strain of a muscle, tendon or ligament, joint dysfunction such as back or knee pain. This pain is also present in any form of arthritis where degeneration has occurred in bone or soft tissue structures. Myofascial pain is often present especially in areas of the back where trigger points are found that may cause pain and stiffness.

Headaches are a common complaint that may be present due to nervous or muscle tension, compression of upper cervical nerves and blood vessel compression such as in trigeminal neuralgia. Migraine may be a combination of circulatory and neural involvement.

Conditions such as fibromyalgia may be a combination of myofascial pain in many areas of the torso and limbs, reduced immune responses and autonomic symptoms such as sweating and nausea. Failed back syndromes are present in those who may have had one or more surgical procedures to the spinal vertebrae and nervous system. In this condition nociceptive and neuropathic pain is present as a result of surgical intervention and ongoing chronic pain.

Herpes zoster or shingles is a virus that may attack nerve endings such as in the trigeminal or occipital nerves and the spine among others producing severe pain in a distinctive area that may develop a rash.

Other neuropathic pain conditions may develop from trauma in a limb and produce a complex regional pain syndrome in which pain, circulatory changes and reduced mobility occur. Trauma may also occur after any type of surgery especially thoracic surgery and the wound itself may become a source of severe pain and neural disturbance. Other types of neuropathy occur in which severe pain and circulatory disturbances are found in diabetic neuropathy, trigeminal neuralgia, AIDS, post-amputation (phantom limb pain, even the breast post mastectomy), multiple sclerosis, para and quadriplegia, cancer, post stroke central pain and any disease that attacks the neurological system.

Mandy: Can you give me a broad based approach to pain management? 

Phyllis: The International Association for the Study of Pain defines pain as “An unpleasant sensory and emotional experience arising from actual or potential tissue damage or described in terms of such damage”. However the definition of pain that is most appropriate for use in clinical practice was given by Margo McCaffrey in 1968. He defined pain as “whatever the experiencing person says it is, existing whenever he says it does.”

From this explanation of pain we can understand that the management of pain is not simple and often requires a multi-disciplinary approach to deal with the many aspects of pain, especially chronic pain. And this includes understanding of the context of the individual patient, the condition and the psychological and social milieu that may be present. It is important to address both the pain mechanisms and the biopsychosocial effects that pain imposes on the psyche of our patients. Pain is viewed as a response with both physiological and psychological factors. The physiological component comprises complex neuronal connections and biochemical processes (Flor, Hermann 2004).

Accurate assessment of the pain condition is essential to establish the correct method of treatment. Most acute and chronic nociceptive pain responds to analgesics and anti-inflammatories. However neuropathic pain rarely responds to this approach and other medications such as anti-epileptics or anti-depressant medication (in specific dosages that are far less than those required to address depression and epilepsy), is required to damp down the disturbances and discharges within the neural system. Opioids may also be used for non-cancer neuropathic pain in certain circumstances, even AIDS, without the risk of addiction.

Another aspect of treating pain, especially musculoskeletal pain involves the non-pharmacological modalities. This may be addressed with physiotherapy that includes mobilisation, massage, ultrasound, electrical currents such as TENS (transcutaneous electrical nerve stimulation), specific exercises and acupuncture which may include dry needling techniques. TENS type currents block pain and if used correctly can break the pain cycle. There are many recently developed electrical currents that address inflammation and disturbed nerve conduction and these have proved successful in treating different types of neuropathic pain. It has been found that high frequency currents block pain in the spinal cord and brain and have the capacity to produce endorphins and serotonin that assist in pain relief.

Pain relief also includes restoration of normal activities and the most recent evidence based information that medical science accepts for pain rehabilitation is mobilisation, all forms of movement – exercise, including hydrotherapy, acupuncture and certain electrical currents. Studies have shown that acupuncture combined with most forms of treatment will enhance pain relief.

It is appropriate to mention that breathing exercise, relaxation and meditation or visualisation also improves pain relief by activating certain mechanisms in the brain that reduce autonomic (sympathetic nervous system) activity and increase endorphin release.

Studies have shown that being able to be attended by a caring and listening medical attendant, expressing oneself fully on all aspects of the condition and the life situation, release of old and sub-conscious emotions (a psychologist may assist), following one’s own beliefs, reducing fear, anxiety, attention to pain, dysfunctional mobility, hypervigilance and catastrophising all assist in improving pain relief. Becoming disturbed and anxious actually increases substances such as noradrenalin which enhances sensitisation in nerve endings so it is important to learn to accept pain, once it is known that there is no danger from this chronic pain. One needs to balanceimproved coping mechanisms by not overdoing activities that may aggravate one’s pain with those that allow one to continue with normal life such as shopping, cleaning or working. It is important to also engage in distracting and pleasant activities to achieve improvement in the quality of life.

There are other interventions such as injections into the spinal cord, burning or freezing nerve endings peripherally or centrally to block severe pain and as a last resort having an electrical device implanted next to the spine to alter pain sensations. Patients may also attend a pain clinic where usually an anaesthetist will oversee the pain management process providing access to pharmacological treatment, injections or interventions, physiotherapy, occupational therapy and psychotherapy.

Mandy: What kinds of effects does severe chronic pain have on sufferer’s lives? 

Phyllis: Chronic pain causes suffering because it interacts with our behaviour and affects our thoughts and feelings. Many patients experience a sense of loss of the life that they once knew as an active and contributing individual. They may feel less of a person when they cannot contribute financially, physically or even sexually. They may lose the quality of life that encourages a person to continue and depression, anxiety and fear of pain or further damage often develops.

It is true that pain often begets pain! The more pain a patient experiences, the greater the likelihood of a general increase of muscle spasm, reduced breathing capacity and oxygen intake, increased sympathetic nervous system activity, stress and reduced circulation in the whole region as well as the microcirculation of the local area (Berger 2003). We also know that depression itself may increase nerve activity and therefore contribute to pain.

The patient therefore does have reason to fear pain as pain may never disappear completely and often the patient has to change their thought processes and learn to live alongside the pain in such a manner that the pain becomes less important within that lifestyle.

Mandy: Obviously treatment will depend on the causes of the pain but what are some examples of effective pain treatment? 

Phyllis: If we take one of the commonest problems that affect at least 80% of people in their lifetime – back pain – we can discuss the treatments available.

Unless in an acute stage, patients are not encouraged to rest for more than 72 hours as inactivity seems to disconnect that back area from the brain’s motor region and disuse of the region leads to weakness, increased instability and further pain. There is usually a degree of inflammation that occurs and often the development of muscle spasm therefore analgesics, anti-inflammatories, muscle relaxants and even an anti-inflammatory injection may ease the condition without further ado. Exercise that focuses on the ‘core’ muscles – the abdominal and back muscles will protect the spine, improve mobility and once again enable the patient to engage in normal activities.

If the condition persists the patient may consult the physiotherapist for mobilisation, dry needling which is a modality that stems from acupuncture, acupuncture – traditional or western medical acupuncture, electrical currents that relieve pain and inflammation and specific exercises. Traction may be necessary if a spinal nerve is compressed as this stretches the spine and may release a trapped nerve.

A patient should provide time for the condition to settle as most acute back conditions improve within six weeks. If there are continuing problems the patient may require:

a spinal epidural injection which will relieve inflammation; a visit to the neurologist, orthopaedic or neurosurgeon to decide if further interventions are necessary.

Most patients will benefit from exercise that does not increase their pain – this may be Pilates, Yoga, Tai chi, hydrotherapy or a gym programme. If pain increases with the activity then the patient needs to find the exercise that suits their disposition and their condition but enjoyment will definitely produce compliance!

Mandy: Are there any advances in pain management? 

Phyllis: New drugs are constantly being developed that strive to alter nerve conduction through various regions of the nervous system including the brain. Deep brain stimulation has also been shown to ease some intractable pain states such as post stroke central pain. Developments are also occurring in electrical devices that produce different frequencies and magnetic fields that may break the pain cycle and these are valuable as there are almost no side effects from electrical treatments. It also gives patients more control of their lives especially if they are able to use a device themselves when in need.

Interventional techniques such as ablation of nerves both in the spine and locally are also being refined and an organisation such as the International Association for the Study of Pain which developed in the early 1970’s is constantly encouraging improved scientific research and is also involved in educating its multi-disciplinary members on improved pain management.

Mandy: Is there anything that you would like to add? 

Phyllis: Patients need to take responsibility for their pain, learn to help themselves and find methods that best suit their condition to achieve a good quality of life despite the pain! The patient is regarded as the team leader and needs to communicate with those consulted so that there is a proper understanding of the condition and a positive treatment plan is developed.

Spread the word