Attrition with spinal cord stimulation

The aim of this prospective study was to investigate whether spinal cord stimulation (SCS) significantly reduces pain intensity for up to 18-month follow-up in patients with chronic neuropathic pain. Forty-eight patients were recruited. Patients rated their pain using a Visual analog scale (VAS) and pain-related disability using the Oswestry Disability Index (ODI) at baseline (1 week prior to SCS surgery) and at 6-, 12-, and 18-month follow-up. Pain intensity significantly decreased from baseline to all 3 time points [F (3,135) = 16.264, p < 0.001]. The greatest difference in the reduction of pain intensity was observed between baseline (M = 7.20, SD = 1.34) and 6-month follow-up (M = 4.60, SD = 2.20), [t(47) = 6.741, p < 0.001]. However, when looking at differences between the 6-month follow-up and subsequent assessments, statistically significant increases in pain intensity from the 6-month to the 12-month follow-up [t(47) = -2.788, p = 0.008], and from the 6-month to the 18-month follow-up [t(47) = -3.339, p = 0.002] could be observed. Statistically significant changes were also observed for clinical changes in pain scores [F (2,94) = 4.972, p = 0.009. There was a significant decrease in the percentage of clinical change obtained from the 6-month (M = 33.19, SD = 35.63) to the 12-month follow-up (M = 23.76, SD = 33.62), [t(47) = 2.347, p = 0.025], and from the 6-month to the 18-month follow-up (M = 18.34, SD = 33.51), [t(47) = 3.072, p = 0.004]. A number of patients also reported higher levels of pain intensity at the 12-and 18-month follow-up than at baseline.Pain-related disability scores significantly decreased from baseline (M = 55.04, SD = 16.43) to the 6-month follow up (M = 46.98, SD = 19.05), [t(47) = 3.464, p = 0.001] and from baseline to the 12-month follow up (M = 48.49, SD = 20.94), [t(47) = 2.918, p = 0.005], but not during the 18-month follow up (M = 51.75, SD = 20.92), [t(47) = 1.330, p =.190]. There was a significant increase in pain-related disability between the 6- and the 18-month follow up [t(47) = -2.188. p = 0.034]. These findings suggest that the beneficial effect of SCS on pain intensity may diminish over time, and that the 6-month follow-up scores may reflect a placebo effect. © 2015 The Neurosurgical Foundation

Effect of one session of mirror therapy on phantom limb pain and recognition of limb laterality in military traumatic lower limb amputees: a pilot study

Up to 70 % of military amputees suffer phantom limb pain (PLP), which is difficult to treat. PLP has been attributed to cortical reorganisation and associated with impaired laterality. Repeated sessions of mirror therapy (MT) can benefit PLP; however, anecdotal evidence suggests one MT session could be effective. In a one-group pretest and post-test design, 16 UK military unilateral lower limb amputees (median age: 31.0, 95% CI 25.0 to 36.8 years) undertook one 10  min MT session. Visual analogue scale (VAS) pain and laterality (accuracy and reaction time) measurements were taken pre-MT and post-MT. Median VAS PLP did not differ significantly between pre-MT 15 mm (2–53 mm) and post-MT 12 mm (1–31) (p=0.875) scores. For the amputated limb, there were no significant differences between pre-MT and post-MT scores for laterality accuracy, 95.3%, 95% CI 90.5% to 97.6% and 96.7%, 95% CI 90.0% to 99.4%, respectively (p=0.778), or reaction time, 1.42 s, 95% CI 1.11 to 2.11  s and 1.42 s, 95% CI 1.08 to 2.02  s, respectively (p=0.629). Laterality was also not different between limbs for accuracy, p=0.484,  or reaction time, p=0.716, and did not correlate with PLP severity. No confounding variables predicted individual responses to MT. Therefore, one 10  min MT session does not affect laterality and is not effective as standard treatment for PLP in military lower limb amputees. However, substantial PLP improvement for one individual and resolution of a stuck phantom limb for another infers that MT may benefit specific patients. No correlation found between PLP and laterality implies associated cortical reorganisation may not be the main driver for PLP. Further research, including neuroimaging, is needed to help clinicians effectively target PLP

Analysis of psychological characteristics impacting spinal cord stimulation treatment outcomes:a prospective assessment

Background: Psychological factors are recognised as influencing the outcome of spinal cord stimulation (SCS) although there is currently no consensus as to which factors impact upon SCS efficacy. Objective: To identify psychological characteristics that may impact the efficacy of SCS. Study Design: Prospective evaluation. Setting: Single secondary care center in Dudley, United Kingdom. Methods: Patients: Seventy-five patients were initially recruited and 56 patients (31 women and 25 men) were followed-up for 12-months. Intervention: SCS for the management of chronic non-cancer pain. Main Outcome Measures: Outcome measures assessed at baseline, 6 months, and 12 months following SCS implantation included the visual analogue scale (VAS), Oswestry disability index (ODI), hospital anxiety and depression (HAD) scale, and the pain coping strategies questionnaire (PCSQ). Results: Statistically significant improvements were observed for the VAS (P < 0.001), ODI (P = 0.011), anxiety (P = 0.042), and depression (P = 0.010) in the HAD scale and for the subscales reinterpreting pain sensation (P = 0.018), control over pain (P = 0.001), and ability to decrease pain (P < 0.001) of the PCSQ. We observed that depression and autonomous coping (control over pain, ability to reduce pain, and catastrophizing) may impact sensory aspects such as pain intensity and disability scores affecting the outcome of SCS treatment. Age at time of implant and duration of pain prior to implant were also found to impact SCS efficacy. Limitations: It has been reported that loss of analgesia may be experienced within 12 to 24 months following SCS implantation and therefore, it would be of interest to follow patients over a longer period. Conclusions: This study demonstrates that psychological aspects such as depression and autonomous coping may impact SCS treatment. Addressing these issues prior to SCS implantation may improve SCS long-term outcome. © 2015, American Society of Interventional Pain Physicians. All Rights Reserved

Safety and physiological effects of two different doses of elosulfase alfa in patients with morquio a syndrome: A randomized, double-blind, pilot study.

The primary treatment outcomes of a phase 2, randomized, double-blind, pilot study evaluating safety, physiological, and pharmacological effects of elosulfase alfa in patients with Morquio A syndrome are herewith presented. Patients aged ≥7 years and able to walk ≥200 m in the 6-min walk test (6MWT) were randomized to elosulfase alfa 2.0 or 4.0 mg/kg/week for 27 weeks. The primary objective was to evaluate the safety of both doses. Secondary objectives were to evaluate effects on endurance (6MWT and 3-min stair climb test [3MSCT]), exercise capacity (cardio-pulmonary exercise test [CPET]), respiratory function, muscle strength, cardiac function, pain, and urine keratan sulfate (uKS) levels, and to determine pharmacokinetic parameters. Twenty-five patients were enrolled (15 randomized to 2.0 mg/kg/week and 10 to 4.0 mg/kg/week). No new or unexpected safety signals were observed. After 24 weeks, there were no improvements versus baseline in the 6MWT, yet numerical improvements were seen in the 3MSCT with 4.0 mg/kg/week. uKS and pharmacokinetic data suggested no linear relationship over the 2.0-4.0 mg/kg dose range. Overall, an abnormal exercise capacity (evaluated in 10 and 5 patients in the 2.0 and 4.0 mg/kg/week groups, respectively), impaired muscle strength, and considerable pain were observed at baseline, and there were trends towards improvements in all domains after treatment. In conclusion, preliminary data of this small study in a Morquio A population with relatively good endurance confirmed the acceptable safety profile of elosulfase alfa and showed a trend of increased exercise capacity and muscle strength and decreased pain