Pain
The reported prevalence of chronic pain after spinal cord injury (SCI) is 48 – 94%, with nearly one third rating their pain as severe [1]. Chronic pain is defined as pain persisting for 6 months or more, and having the potential to disrupt physical functioning beyond the parameters imposed by the SCI [2]. Chronic pain is one of the most challenging medical problems associated with SCI [3], and is often perceived as difficult to deal with by the person experiencing it [4], as well as by the health care providers managing it [2].
In general, there are two broad categories of pain: neuropathic and nociceptive pain [5].
Nociceptive pain is the result of the normal processing of stimuli that damage or disturb normal tissues. Nociceptive pain typically occurs above the level of the spinal cord lesion, has an identifiable cause, and may result from musculoskeletal problems such as fractures, rotator cuff-tears, or from visceral (abdominal) problems.
Neuropathic pain is more complex and results from the abnormal processing of sensory input due to damage to the nervous system [6]. Although neuropathic pain can be identified by site (region of sensory disturbance) and by features (sharp, shooting, electric, burning, stabbing), it is difficult to identify a specific stimulus or cause, and persons with SCI may find it difficult to describe the quality of neuropathic pain [6]. Typically, neuropathic pain is present at or below the level of the spinal cord lesion, and is constantly present but fluctuates in intensity depending on the individual’s emotional state or level of fatigue [7].
It should be noted that a third sub-type of pain, visceral pain, is also a problem for persons with SCI but is one that has been the least researched [8]. Visceral pain that originates from deep visceral structures and is often localized to the abdomen and characterized as being ‘dull’ or ‘cramping’ [9]. It is a clinical entity with multiple etiologies, of which many remain unknown [8], but probably have both central and peripheral components [10].
The presence of pain and difficulties with its management may impede a person’s initial SCI rehabilitation and subsequently impede community re-integration [5, 11, 12]. Chronic pain in people with SCI affects sleeping patterns [5], vocational status [5], sexuality [13], leisure time activities [14], activities of daily living [15], and quality of life (QoL) over and above the consequences of their injury [5]. As well, chronic pain after SCI has been found to be a contributing factor in suicide [16]. Although SCI-related chronic pain has been an under-researched and somewhat ignored topic until recently [17, 18], there are several outcome measures available to researchers and clinicians interested in evaluating the impact of chronic pain on QoL and participation.
The study of SCI-related pain presents a number of challenges. Unlike the majority of other secondary health conditions, SCI-related chronic pain not only impacts on QoL and participation, but the expression of pain has been shown to be influenced by these constructs as well. For instance, social environment factors, such as social support, and affective factors, have been found to influence pain severity and interference in persons with SCI-related pain [19, 20]. Hence, it is important to apply a biopsychosocial perspective to conceptualize the development and maintenance of chronic pain disorders [21, 22]. Contemporary biopsychosocial models acknowledge a role for biological factors in pain, but also argue that psychosocial variables can, and do, influence pain and functioning in all persons, regardless of the source of pain or the presence of psychopathology [21].
Chronic pain after SCI remains a common and potentially devastating secondary health condition that negatively impacts on quality of life.
References
1. Siddall PJ, Loeser JD. Pain Following Spinal Cord Injury. Spinal Cord 2001;39:63-73.
7. Scadding J. Neuropathic pain. Adv Clin Neurosci Rehabil 2003;3:8-14.
10. Ness TJ. Chronic abdominal, groin, and perineal pain of visceral origin. In: Wilson P, Haddox D, Jensen T, editors. Textbook of clinical pain management. London, England: Arnold; 2003. 567-86.
16. Kewman DG, Tate DG. Suicide in SCI: A psychological autopsy. Rehabil Psychol 1998;43:143-51.
17. Beric A. Spinal cord injury pain. Euro J Pain 2003;7:335-8.