Lupus
Pain Management for Lupus Patients
Pain Management for the Lupus Patient
SLE is a disease which may involve different organ systems to varying degrees. The effect of the disease on the various organs may lead to painful conditions that may be acute or chronic in nature. Chronic pain is more difficult to treat than acute pain for two reasons. First, by definition, the pain is persistent and, presumably, has failed to resolve itself spontaneously or to respond to previous treatments. Secondly the impact and duration of the pain ultimately creates altered behavior in the patient. The objectives of this lecture will be to review the currently used terminology of pain, the neurophysiology of pain the more commonly experienced pain disorders associated with lupus, and pain treatments, We will also discuss the importance of a multidisciplinary approach to chronic pain management.
The International Association for the Study of Pain (IASO) has defined pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue
damage, or described in terms of such damage”.
(1) This definition may be surprising to many people as it recognized pain not as a sensation but as an experience. We recognize in science that virtually all humans are endowed with five senses: sight, smell, hearing, touch and taste. To recognize pain as an experience rather than a sensation, one must first recognize that sensations neuroanatomically have discrete pathways with specific receptors to allow detection and measurement of a stimulus. In contrast, an experience incorporates sensory components with important personality and environmental influences. The sensory component of pain is described as nociception. Nociception is the physiological response to tissue injury. Nociception is the progenitor to the experience of pain, which in turn creates suffering. Nociceptive pain and suffering are internal to the organism and cannot be measured directly. However, they do create recognizable impacts on behavior, which can be identified, described and subsequently measured.
(2) The medical treatment of pain is facilitated by a basic understanding of the neuroanatomy and physiology of pain processing. The nociceptors are pain sensitive neurons that respond to noxious mechanical, chemical, and thermal forces. They are located in the skin, vessels, muscles, fascia, joints, and viscera. They are defined as A delta and C fibers. These nociceptors make up the primary afferent neuron whose cell bodies lie within the dorsal root ganglion adjacent to the spinal cord. Nociceptive signals are conducted through the primary afferent to the central nervous system via these primary afferents. The primary nociceptors synapse in the dorsal horn onto second order neurons, predominantly within Lamina II (substantia gelatinosa) of the spinal cord. These second order neurons cross the spinal cord and ascend in the spinal thalamic tract with their terminal fibers predominantly localized in the thalamus. Once the signal has reached the thalamus, third order neurons send subsequent axons through the internal capsule to the somatosensory cortex, including the post central gyrus, where discrete localization of the noxious stimulus occurs.
In addition to somatosensory localization, fibers from the interlaminar and medial nuclei of the thalamus radiate to the anterior cingulate gyrus and become involved in the emotional components of pain. During the process of signal transmission to the thalamus, some fibers from the spinal thalamic tract appear to arborize in the midbrain and rostra1 pons synapsing on nuclear complexes, including the nucleus raphe magnus and nucleus reticularis gigantocellularis, both of which appear to be involved in some descending regulation of the activity within the second order neurons. The excitatory neurotransmitters involved in this descending noxious inhibition including endorphins and kephalins, serotonin, and epinephrine, all appear to inhibit the firing of second order neurons in the presence of a noxious stimulus. The complicated interactions occurring within Lamina II of the spinal cord seems to mirror many of the other neuroanatomical connections identified in this switching station called the dorsal horn.
Lupus pain presents most frequently as arthritis, arthralgias, myalgias, fibromyalgia, neurological problems, hematological processes and by iatrogenic causes. The treatment of each painful condition involves treating the acute lupus process, if it is present, and then treating the pain symptomatically. This may involve the more commonly used agents such as the non-steroidal anti-inflammatory agents, steroids, anti-malarial agents, or cytotoxic agents. Treatment should include education, pharmacological intervention, physical therapy, behavior modification, family counseling, as well as nerve blocks and procedures if appropriate.
The World Health Organization for Cancer Pain recommends a “three step analgesic ladder” approach for pain medication such that medication with the least side effects and the least addicting potential are prescribed first. I believe this approach is appropriate for medical management of non-cancer pain as well. While many physicians may question the use of opioids for non-cancer pain, current opinion favors this consideration on an individual basis. Additional medication is thus added to the “first step of the ladder” as needed. Each therapy must be carefully planned and the benefits of the treatment noted. Iatrogenic problems are seen, such as avascular necrosis and osteoporosis from the steroids, and gastric upset and bleeding from the non-steroidal agents. Occasionally a patient will experience severe “suffering” from their pain and it will have a detrimental impact on their ability to function, their mood, social encounters, and their ability to obtain gainful employment, This will most likely be noted in the patients who have failed the “usual pain therapy” for lupus-related conditions. This is well documented for the patients suffering from lupus as well as fibromyalgia.
The causes of this severe suffering may be multifactorial: unresponsive pain relief to the “usual” non-opioid treatments by pain which may respond to opioids, a “plasticity” has occurred and the pain threshold is lower than normal leading to an increased sensation of pain to less stimuli (hyperalgesia), neuropathic pain exists which responds to na-channel blockers or antiseizure medications, or the “suffering” and “pain experience” is complicated by childhood traumas or other past experiences. Occasionally antidepressants, sleeping agents, and even phenothiazines can be used to treat pain as well. Patients who “fail to respond to normal pain medicine” often do best when their pain is managed with a multidisciplinary approach. This may include, but does not need to include, a referral to a pain management center. Multidisciplinary pain management includes not only medication trials as mentioned above, but also an introduction to gentle reconditioning by a referral to a physical therapist as well as to a pain psychologist. The focus of the psychologist is to teach patients coping skills to be used for pain management.
This is most often done through cognitive behavior therapy. This includes relaxation techniques, biofeedback, and self-hypnosis. These treatments are not meant to replace medications and procedures, if indicated, but to be used as an adjunct to therapy. The primary focus of this pain management treatment would include not only decreasing the pain experience, but also to increase the patient’s overall function and activity.