Pain following spinal cord injury

Abstract: The aims of this thesis were to assess and characterise nociceptive and neuropathic pain, the use of pharmacological and non-pharmacological pain treatment, and the influence of pain on the quality of sleep in a population following spinal cord injury (SCI). This thesis is divided into five separate studies: I. Pain in a Swedish spinal cord injury population. II. Gender related differences in pain in spinal cord injured individuals. III. Use of analgesic drugs in individuals with spinal cord injury. IV. Non-pharmacological pain-relieving therapies in individuals with spinal cord injury: a patient perspective. V. Quality of sleep in individuals with spinal cord injury; a comparison between patients with and without pain. Paper I encompassed 456 individuals with an SCI, which was 76.5% of the total prevalence population in the greater Stockholm area. In paper II, 65 women were matched with 65 men regarding age, ASIA impairment grade, and level of lesion. These patients were followed up 3 years later regarding the use of analgesic drugs (III) and non-pharmacological treatment (IV). They were also assessed regarding quality of sleep together with a sample of 107 patients with SCI (V). Of 456 patients with an SCI (I), 291 (63.7%) suffered from pain: of these, 46% had pain classified as neurogenic and 26% as both nociceptive and neurogenic. Onset of pain was most often within 3 months and localised to areas below the level of the lesion. The median rating of the general pain intensity was 46/100 on a visual analogue scale. Pain was most common in patients with motor and sensory incomplete lesions, ASIA impairment grade D, and there was a correlation between pain and higher mean age at injury and between pain and female gender. In paper II we found that although men and women described their pain similarly, more women were classified as sufferers from nociceptive pain. The use of analgesics was higher amongst women, especially the use of opiates and non-steroidal anti-inflammatory drugs. At the 3-year follow-up, the remaining 123 patients had increased the number of drugs they used for pain relief, but the ratings of pain intensity were similar to those 3 years before. Predictive for the use of analgesics were high ratings of the affective component of pain, low ratings of leisure time activities, and the presence of stabbing/cutting pain. Regarding the use of non-pharmacological treatment (IV), 63.3% had tried one or more treatments for pain relief. Acupuncture, massage therapy, and transcutaneous electrical nerve stimulation were the most commonly tried therapies. Patients considered massage and treatment with heat to give best pain alleviation. Predictive for the use of non-pharmacological treatment were high ratings of general pain intensity, aching pain, and cutting/stabbing pain. In the last study (V) we assessed quality of sleep in patients without pain, with intermittent pain, and with continuous pain. We found that the latter reported a poorer quality of sleep than did patients with intermittent pain or no pain. Predictive for poor sleep quality were anxiety, ratings of the worst pain intensity, and depression. This thesis concludes that pain after spinal cord injury is common - often debilitating - and that relief of pain is difficult to obtain with the pharmacological and non-pharmacological treatment options available today. Pain also interferes negatively with the quality of sleep. Patients with SCI and pain suffer from a common complication and need a multidisciplinary team for assessment and treatment to decrease not only the intensity of the pain but also the suffering and the consequences of pain.