Neuropathic pain intensity, unpleasantness, coping strategies, and psychosocial factors after spinal cord injury: an exploratory longitudinal study during the first year.

OBJECTIVE: To determine the temporal relationship between pain-related coping strategies and psychosocial factors with non-evoked neuropathic pain (NP) intensity and unpleasantness in patients during the subacute phase of spinal cord injury (SCI). DESIGN: Exploratory longitudinal study of NP from 2 to 12 months. SETTING: Hospital Nacional de Parapléjicos, Toledo, Spain. SUBJECTS: A maximum of 26 patients with early symptoms of NP after SCI with a neurological level above the Th10 spinal level. OUTCOME MEASURES: Multidimensional Pain Inventory-Spinal Cord Injury Version, Coping Strategies Questionnaire, General 7-day pain intensity and unpleasantness rated with a visual analog scale, Spearman correlation analysis. RESULTS: PAIN-related coping strategies and psychosocial factors remained stable from 2 to 12 months after SCI. Initially pain intensity and unpleasantness were rated independently, but at 6 months were intercorrelated along with "pain severity,""life interference," and "catastrophizing.""Coping self-statements" and "solicitous responses from others" were frequently adopted, compared with "ignoring pain sensations" and "catastrophising." Perception of "pain severity" correlated with "support,""solicitous responses from others,""distracting responses from others," and "life control" at 6 months, while pain intensity and unpleasantness were related to "coping self-statements,""catastrophizing,""distancing from pain," and "praying." CONCLUSIONS: Pilot longitudinal data suggest that pain-related coping strategies are adopted early after subacute SCI, and correlate with both pain intensity and unpleasantness. Future longitudinal studies of SCI with sufficient sample size will be instrumental to determine the causal relationship between psychosocial factors and coping strategies on pain.

Validity and reliability of the Spanish version of the DN4 (Douleur Neuropathique 4 questions) questionnaire for differential diagnosis of pain syndromes associated to a neuropathic or somatic component.

BACKGROUND: This study assesses the validity and reliability of the Spanish version of DN4 questionnaire as a tool for differential diagnosis of pain syndromes associated to a neuropathic (NP) or somatic component (non-neuropathic pain, NNP). METHODS: A study was conducted consisting of two phases: cultural adaptation into the Spanish language by means of conceptual equivalence, including forward and backward translations in duplicate and cognitive debriefing, and testing of psychometric properties in patients with NP (peripheral, central and mixed) and NNP. The analysis of psychometric properties included reliability (internal consistency, inter-rater agreement and test-retest reliability) and validity (ROC curve analysis, agreement with the reference diagnosis and determination of sensitivity, specificity, and positive and negative predictive values in different subsamples according to type of NP). RESULTS: A sample of 164 subjects (99 women, 60.4%; age: 60.4 +/- 16.0 years), 94 (57.3%) with NP (36 with peripheral, 32 with central, and 26 with mixed pain) and 70 with NNP was enrolled. The questionnaire was reliable [Cronbach's alpha coefficient: 0.71, inter-rater agreement coefficient: 0.80 (0.71-0.89), and test-retest intra-class correlation coefficient: 0.95 (0.92-0.97)] and valid for a cut-off value > or = 4 points, which was the best value to discriminate between NP and NNP subjects. DISCUSSION: This study, representing the first validation of the DN4 questionnaire into another language different than the original, not only supported its high discriminatory value for identification of neuropathic pain, but also provided supplemental psychometric validation (i.e. test-retest reliability, influence of educational level and pain intensity) and showed its validity in mixed pain syndromes.