Long-Term Evaluation of Spinal Cord Stimulation in Patients With Painful Diabetic Polyneuropathy: An Eight-to-Ten-Year Prospective Cohort Study.

OBJECTIVE: This study aimed to evaluate the long-term effects of spinal cord stimulation (SCS) in patients with painful diabetic polyneuropathy (PDPN). MATERIALS AND METHODS: This prospective cohort study was the eight-to-ten-year follow-up of a previously performed pilot and randomized controlled trial on the effects of SCS in PDPN, initiated by the multidisciplinary pain center of Maastricht University Medical Center+. The study population consisted of a subgroup of patients who still used SCS treatment ≥ eight years after implantation (n = 19). Pain intensity scores (numeric rating scale [NRS]) during the day and night and data on secondary outcomes (ie, quality of life, depression, sleep quality) were reported during yearly follow-up consultations. Long-term efficacy of SCS was analyzed by comparing the most recently obtained data eight to ten years after implantation with those obtained at baseline. RESULTS: Pain intensity, day and night, was significantly (p < 0.01) reduced by 2.3 (NRS 6.6-4.3) and 2.2 (NRS 6.8-4.6) points, respectively, when comparing the long-term data with baseline. Moreover, for > 50% of patients, the pain reduction was > 30%, which is considered clinically meaningful. No differences were found regarding the secondary outcomes. CONCLUSION: This eight-to-ten-year follow-up study indicates that SCS can remain an effective treatment in the long term to reduce pain intensity in a subcohort of patients with PDPN who still had an SCS device implanted after eight years.

Do Men and Women Have a Different Association between Fear-Avoidance and Pain Intensity in Chronic Pain? An Experience Sampling Method Cohort-Study.

BACKGROUND: Fear-avoidance is one of the factors associated with chronic pain. However, it remains unclear whether the association between fear-avoidance and pain depends on sex. The present study aimed to investigate whether the association between fear-avoidance and pain intensity differed between men and women in chronic pain patients. Additionally, the potential confounding effect of affective experiences on the association between fear-avoidance and pain intensity was analyzed. METHOD: This cohort study included hospital referred chronic pain patients (n = 45). Short momentary assessment questions according to the experience sampling method (ESM) were used to repeatedly assess patients' pain intensity, level of fear-avoidance and positive as well as negative affect during their daily life. Linear mixed-effects models were applied in the statistical analysis. Unadjusted and adjusted models were made, in which the latter corrected for statistically significant affective experiences and baseline variables, taking the Aikake Information Criterion into account to assess a better model of fit. RESULTS: The results demonstrated an association between fear-avoidance and pain intensity that differed for men and women. In men (n = 13), no association between these variables was found (-0.04 (95% CI: -0.14, 0.06) with a p-value of 0.48), whereas in women (n = 32), an increase in fear-avoidance was associated with a (slight) increase in pain intensity (0.18 (95% CI 0.06, 0.30) with a p-value of 0.003). Affect did not confound the above-mentioned findings. CONCLUSION: Our data supports previous research highlighting the importance of sex differences in pain experience. These findings may be relevant for clinicians to consider more personalized (i.e., gender specific) pain management in chronic pain patients.