Life satisfaction in patients with long-term non-malignant pain - relating LiSat-11 to the Multidimensional Pain Inventory (MPI).

BACKGROUND: The West-Haven Multidimensional Pain Inventory (MPI) can be used to describe behavioural and psychosocial consequences of long-term pain but little is known about how MPI items and MPI subgroups relate to goals that patients find important in rehabilitation. Life satisfaction measured by the LiSat-11 checklist can be defined as an individual's perception of the difference between his reality and his needs or wants. This difference can be considered a "goal achievement gap". This study investigates the relation of MPI to LiSat-11 with the aim to explore the possibility that LiSat-11 can be used to measure pain rehabilitation outcomes that are important from the patients' view. METHODS: Participators were patients (n = 294) referred to the Pain and Rehabilitation Clinic in Uppsala, Sweden. Measures used were LiSat-11, MPI and its Swedish version MPI-S. LiSat-11 domains were correlated to MPI scales. Cluster analysis was used to demonstrate MPI-S subgroups. Analysis of variance followed by post-hoc analysis was used to investigate life satisfaction in the three MPI-S subgroups. RESULTS: The strongest positive correlation were found for the LiSat-11 domains/MPI scales: psychological health/life control and contacts/social activities, and the strongest negative correlation for: psychological health/affective distress, partner relationship/punishing responses, somatic health/interference and leisure/interference. None or only little correlation was found between MPI scale pain severity and most LiSat-11 domains and satisfaction with life as a whole. Among the MPI-S subgroups, adaptive copers generally had better life satisfaction than the dysfunctional and the interpersonally distressed. CONCLUSION: Pain severity alone is a rather poor predictor of low life satisfaction. MPI and LiSat-11 partly supplement each other as tools to describe how functional impairments relate to life satisfaction domains, which may be relevant for identifying domains which the patients find important to improve. Furthermore, differences in life satisfaction between the MPI-S subgroups may help to identify functional domains that may be of particular importance in specialised rehabilitation programs.

Life satisfaction in patients with long-term non-malignant pain-relation to demographic factors and pain intensity.

PURPOSE: Life satisfaction can be defined as a measure of a patient's perception of the difference between his reality and his needs or wants. Here we compare life satisfaction in patients with long-term pain to a reference group sampled from the normal population, and relate the results to pain intensity and to demographic factors. METHOD: Questionnaires containing the Life satisfaction (LiSat-11) checklist, a visual analogue scale (VAS) for pain, and questions on demographic background. RESULTS: The prevalence of responders with low level of life satisfaction was larger among the patients than in the reference group. In particular, patients born outside Northern Europe scored significantly lower than patients born in Northern Europe in many of the LiSat-11 domains. Pain intensity did not correlate well to the level of life satisfaction, except for weak negative correlations to satisfaction with physical health and with financial situation. CONCLUSION: Long-term pain is strongly associated with low life satisfaction. In order to increase life satisfaction, interventions related to social factors seem to be important.

Estimations of topographically correct regeneration to nerve branches and skin after peripheral nerve injury and repair.

Peripheral nerve injury is typically associated with long-term disturbances in sensory localization, despite nerve repair and regeneration. Here, we investigate the extent of correct reinnervation by back-labeling neuronal soma with fluorescent tracers applied in the target area before and after sciatic nerve injury and repair in the rat. The subpopulations of sensory or motor neurons that had regenerated their axons to either the tibial branch or the skin of the third hindlimb digit were calculated from the number of cell bodies labeled by the first and/or second tracer. Compared to the normal control side, 81% of the sensory and 66% of the motor tibial nerve cells regenerated their axons back to this nerve, while 22% of the afferent cells from the third digit reinnervated this digit. Corresponding percentages based on quantification of the surviving population on the experimental side showed 91%, 87%, and 56%, respectively. The results show that nerve injury followed by nerve repair by epineurial suture results in a high but variable amount of topographically correct regeneration, and that proportionally more neurons regenerate into the correct proximal nerve branch than into the correct innervation territory in the skin.

Vibratory stimulation increase the electro-cutaneous sensory detection and pain thresholds in women but not in men.

BACKGROUND: Vibratory stimulation is a potential method for the treatment of pain. METHODS: The effect of vibration on the forearm on detection (DT) and pain thresholds (PT) induced by electro-cutaneous stimulation were investigated in healthy male and female volunteers. RESULTS: Women have lower baseline detection and pain thresholds as compared to men. Furthermore, women but not men report increased detection and pain thresholds after vibratory stimulation. CONCLUSION: Our findings indicate the potential usefulness of vibratory stimulation for pain treatment, and that gender differences should be considered in future evaluation of the method.

On regenerative and collateral sprouting to hind limb digits after sciatic nerve injury in the rat.

PURPOSE: This study examines the proportions of regenerative and collateral sprouting to the skin after peripheral nerve injury. METHODS: In the first experimental paradigm, primary afferent neurones were pre-labelled with Diamidino Yellow (DY), injected in digit 3, followed by sciatic nerve section and repair. After three months of regeneration, digit 3 was re-injected with Fast Blue (FB) to label regenerating cells. Fluoro-Gold (FG) was applied to the femoral (FEM) and musculocutaneous (MC) nerves four days later to quantify their contribution to the innervation. In the second experimental paradigm, sciatic nerve was first sectioned and repaired. Three months later, the sciatic was resected, and digit 3 injected with FB. After four more days, FEM and MC were resected and FG injected in all digits. RESULTS: Neurones in dorsal root ganglion (DRG) L5 had a higher rate of correct reinnervation of digit 3 (44-72%) than neurones in DRG L4 (14-44%). Like in control cases, only occasional axons were traced from the FEM and MC. In the second experiment, only occasional labelled neurones appeared. CONCLUSIONS: The results indicate differences in the capacity for correct peripheral sensory reinnervation between segmental levels, and that in this model collateral sprouting was practically non-existent compared to regenerative sprouting.

Prolonged relief of neuralgia after regional anesthetic blocks. A call for further experimental and systematic clinical studies.

Thirty-eight consecutive patients with neuralgia after peripheral nerve injury were treated with one or two series of peripheral local anesthetic blocks. All patients experienced an initial total relief of ongoing pain for 4-12 h. Evoked pain (hyperalgesia or allodynia), which occurred in 17 patients, was blocked simultaneously with the spontaneous pain. In 18 patients the analgesia outlasted the conduction block and there was a period of complete pain relief of 12-48 h in 13 patients and of 2-6 days in the other 5. In 8 patients there was a second phase of analgesia of 4 h to 6 days duration occurring within 12 h of pain recurrence. Thus, mono- or biphasic prolonged complete analgesia occurred in 25 out of 38 patients. A prolonged analgesia may be the result of a central action of the local anesthetic at the spinal level after intra-axonal incorporation and centripetal axoplasmic transport. To test this hypothesis, an experimental study with [3H]lidocaine was performed in 6 rats. The radioactive local anesthetic was injected into one hind limb foot with the other side serving as a control. Tissue samples from the peripheral nerve, nerve root and the lumbosacral spinal cord segment were analyzed for radioactivity using a scintillation counter technique at various time intervals after the [3H]lidocaine injection. There was a low grade of activity in all samples and no difference between the test side and the control side. Thus these experiments provided no evidence in support of this hypothesis. Various alternative peripheral and central mechanisms are discussed. Further studies specifically directed to these alternatives and with longitudinal controls are prompted.

Persistence of tracer in the application site--a potential confounding factor in nerve regeneration studies.

Selective reinnervation of peripheral targets after nerve injury might be assessed by injecting a first tracer in a target before nerve injury to label the original neuronal population, and applying a second tracer after the regeneration period to label the regenerated population. However, altered uptake of tracer, fading, and cell death may interfere with the results. Furthermore, if the first tracer injected remains in the target tissue, available for "re-uptake" by misdirected regenerating axons, which originally innervated another region, then the identification of the original population would be confused. With the aim of studying this problem, the sciatic nerve of adult rats was sectioned and sutured. After 3 days, to allow the distal axon to degenerate avoiding immediate retrograde transport, one of the dyes: Fast Blue (FB), Fluoro-Gold (FG) or Diamidino Yellow (DY), was injected into the tibial branch of the sciatic nerve, or in the skin of one of the denervated digits. Rats survived 2-3 months. The results showed labelled dorsal root ganglion (DRG) cells and motoneurones, indicating that late re-uptake of a first tracer occurs. This phenomenon must be considered when the model of sequential labelling is used for studying the accuracy of peripheral reinnervation.

On the use of fast blue, fluoro-gold and diamidino yellow for retrograde tracing after peripheral nerve injury: uptake, fading, dye interactions, and toxicity.

The usefulness of three retrograde fluorescent dyes for tracing injured peripheral axons was investigated. The rat sciatic was transected bilaterally and the proximal end briefly exposed to either Fast Blue (FB), Fluoro-Gold (FG) or to Diamidino Yellow (DY) on the right side, and to saline on the left side, respectively. The nerves were then resutured and allowed to regenerate. Electrophysiological tests 3 months later showed similar latencies and amplitudes of evoked muscle and nerve action potentials between tracer groups. The nerves were then cut distal to the original injury and exposed to a second (different) dye. Five days later, retrogradely labelled neurones were counted in the dorsal root ganglia (DRGs) and spinal cord ventral horn. The number of neurones labelled by the first tracer was similar for all three dyes in the DRG and ventral horn except for FG, which labelled fewer motoneurones. When used as second tracer, DY labelled fewer neurones than FG and FB in some experimental situations. The total number of neurones labelled by the first and/or second tracer was reduced by about 30% compared with controls. The contributions of cell death as well as different optional tracer combinations for studies of nerve regeneration are discussed.

Improved life satisfaction and pain reduction: follow-up of a 5-week multidisciplinary long-term pain rehabilitation programme.

BACKGROUND: Multidisciplinary rehabilitation programmes can improve physical functioning and help patients with long-term pain back to work. Little is known, however, of the extent to which such rehabilitation also affects life satisfaction, pain severity, and disability. We wanted to evaluate if a 5-week rehabilitation programme for patients with long-term pain improves life satisfaction and decreases pain severity and disability. METHODS: The subjects were 164 patients aged 18-65 years from a pain rehabilitation clinic. Most of them were referred from primary care units. One group of repeated tests was used. Participants were asked to fill out the LiSat-11 checklist and parts of the Multidimensional Pain Inventory (MPI), including pain severity, at admission, at discharge, and 1 year after the rehabilitation programme. RESULTS: Satisfaction with life as a whole, and six of ten LiSat-11 domains improved during the follow-up, though none reached the levels for the general population. MPI subscales pain severity, pain interference, life control, and affective distress improved, whereas no change was observed for general activity. Patients older than 38 years decreased more in MPI affective distress than younger patients. Gender, pain severity, and work status before the programme did not significantly influence the outcome. CONCLUSIONS: The results indicate that multidisciplinary rehabilitation improves life satisfaction, reduces pain severity, and reduces negative psychological, social, and behavioural effects of pain. These outcome variables relate to domains known to be of interest for patients and should therefore be considered for evaluation of rehabilitation programmes for long-term pain.