Subthalamic deep brain stimulation versus best medical treatment: a 12-year follow-up.

PURPOSE: Electrical stimulation of the sub-thalamic nucleus (STN-DBS) is well established to alleviate motor fluctuations in advanced Parkinson's disease but little is known about its very long-term efficacy. METHODS: We followed over 12 years 15 parkinsonian patients having undergone STN-DBS and compared them to a matched group of 14 patients with best medical drug therapy. All had been considered as good candidates for surgery. They were allocated to each group depending on their own decision. RESULTS: After 12 years, mortality rates were similar in both groups. In the DBS group, best "on" UPDRS III scores (on medications, on stimulation) remained significantly better and dyskinesia shorter and weaker than in the drug-treated group (on medication only). Yet, looking at independent life and quality of life (QoL) evaluated with PDQ39, no significant difference could be observed between groups at the end of follow-up, probably due to development of dopa- and stimulation-resistant motor and non-motor symptoms like falls, freezing, dementia, apathy and depression, the latter two more frequent in the DBS group. CONCLUSION: Drug- and DBS-resistant symptoms and signs occur more often after long disease evolution and in elder patients. It might be why differences in QoL between both groups no longer existed after twelve years as, compared to other studies, our patients were older at inclusion.

Long-Term Multicolumn-Lead Spinal Cord Stimulation Efficacy in Patients with Failed Back Surgery Syndrome: A Six-Year Prospective Follow-up Study.

OBJECTIVE: The use of multicolumn-lead spinal cord stimulation (SCS) to control back pain (BP) and leg pain (LP) in patients with failed back surgery syndrome (FBSS) in the short term and mid-term has been well documented. Our study investigated whether SCS remained efficient after 72 months. METHODS: In an observational, single-center study, we assessed SCS efficacy in 62 patients with FBSS patients. BP, LP, and magnitude of daily activity limitation (DAL) were graded using a 0-10 visual analog scale (VAS) preoperatively and at 2, 6, 12, 24, 36, and 72 months after SCS implantation. Sleep quality, use of medications, and complications were also recorded. RESULTS: Of the 62 patients, 15 with complete follow-up data available were still using their SCS device at 72 months (SCS+). For these patients, the VAS scores for BP, LP, and DAL had changed from a median of 9 (interquartile range [IQR], 8.5-10), 7 (IQR, 6-8), and 8 (IQR, 8-9) preoperatively to a median of 4 (IQR, 3-4.5), 3 (IQR, 1.5-3.5), and 3 (IQR, 2-4) at 72 months. Their quality of sleep and analgesic medication consumption had also improved. In a subset of patients no longer using the SCS device after 72 months (SCS-), the VAS scores for BP, LP, and DAL, quality of sleep, and medication consumption were comparable to those for the SCS+ group. The SCS- group was less satisfied with the technique and were less professionally active than were the SCS+ group. CONCLUSIONS: The SCS device provides sustained beneficial effects on BP, LP, DAL, sleep, and medication consumption in patients with FBSS still using it at 72 months postoperatively. Further studies are needed to identify the factors of adherence to the technique and the chances of success compared with the natural evolution of FBSS.

Postoperative Infections Associated With Prolonged Spinal Cord Stimulation Trial Duration (PROMISE RCT).

INTRODUCTION: In the PROMISE study, a multinational randomized controlled trial (RCT) of the effectiveness of spinal cord stimulation (SCS) with multicolumn surgical leads as a treatment of low back pain, clinicians followed their usual practice. An early, unplanned safety analysis revealed that the infection rate in Belgium (5/23), where trial duration was a median 21.5 days, was significantly higher than the 1/64 rate observed in the other study countries (median 5.8 days, p < 0.01). This report reviews infections observed in the PROMISE study after study completion. MATERIALS AND METHODS: For all infections related to SCS, we used descriptive statistics and tests of independent variables to analyze potentially contributing factors (age, sex, coexisting medical conditions, tobacco use, lead type, and trial duration) between subjects with infections versus those without. Cumulative incidence curves were created using the Kaplan-Meier method and compared between the two strata using a log-rank test. RESULTS: Among nine (5.2%) infections in 174 subjects trialed, the only significant contributing factor to infection was trial duration: median 21 days (range 3-56) for those with infection vs. six days (1-41) for those without (p = 0.001; Wilcoxon rank-sum test). The cumulative incidence of infection for subjects trialed >10 days was 24.1% vs. 1.4% for subjects trialed ≤10 days (p < 0.001). After the protocol was amended to limit trial duration to 10 days, 14 infection-free trials were performed in Belgium. CONCLUSIONS: Although not part of the preplanned analysis, our observation supports the hypothesis of a cause-effect relationship between trial duration and the risk of infection and the conclusion that prolonged SCS trials should be avoided.

Treating Low Back Pain in Failed Back Surgery Patients with Multicolumn-lead Spinal Cord Stimulation.

Failed back surgery syndrome (FBSS) refers to persistent, chronic pain following spinal surgery. Spinal cord stimulation with dorsal epidural leads can be used to treat back and leg pain in FBSS patients. This paper presents a detailed protocol for using spinal cord stimulation with surgical leads in FBSS patients. In our department, with the patient under general anesthesia, we place the lead in the epidural space by means of a small laminectomy at the 10th thoracic level. Placement of the lead is followed by a 1 month trial period with an externalized lead. If pain relief is greater than 50% at the end of this 1 month stimulation trial (required by Belgian reimbursement criteria), an internal pulse generator is then placed under the skin and connected to the lead in a second surgical procedure. We have demonstrated that using this technique in rigorously selected FBSS patients can significantly improve back pain, leg pain, patient activity, and quality of life for a sustained period of time.

Effect of Multicolumn Lead Spinal Cord Stimulation on Low Back Pain in Failed Back Surgery Patients: A Three-Year Follow-Up.

OBJECTIVES: Spinal cord stimulation (SCS) remains poorly efficient at reducing back pain in failed back surgery syndrome (FBSS) patients. We aimed at determining whether a new multicolumn lead SCS technique was efficient at durably reducing their leg (LP) and back (BP) pain. MATERIALS AND METHODS: Sixty-two consecutive refractory FBSS patients received multicolumn SCS. Visual analogue scale (VAS) self-evaluation of BP, LP, and limitation of daily activity (LAD) were recorded preoperatively and at 2, 6, 12, 24, and 36 months after surgery. Quality of sleep and use of concomitant medications were also recorded. RESULTS: Complete datasets were obtained in 29 patients. BP (median VAS [25-75 centiles]) significantly decreased from 9 (8.5-10) preoperatively, to 3 (3-4) at short-term follow-up (2 months), and rose up to 5 (4-5) at 36 months. LP evolved from 7 (6-8) preoperatively, to 2.5 (2-3) at short-term follow-up, and 3 (2-3) at 36 months. Correspondingly, LAD VAS was 8 (8-9) preoperatively, and decreased to stable values of 3 (3-4) during the follow-up period. Quality of sleep also improved, with 72% of patients reporting poor sleep preoperatively to 0-7% in the follow-up period until 36 months. The percentages of patients regularly taking analgesic and/or co-analgesic medications decreased from 100% preoperatively to 8, 4, 12, 19, and 19%. CONCLUSION: Multicolumn lead SCS in FBSS patients significantly improve BP, LP, quality of life, and medication consumption for at least 36 months. A classical placebo effect cannot account for long-term improvements of such magnitude.

Herniectomy versus herniectomy with the DIAM spinal stabilization system in patients with sciatica and concomitant low back pain: results of a prospective randomized controlled multicenter trial.

PURPOSE: To investigate the short and medium term efficacy and patient outcomes of DIAM spinal stabilization system on back pain, disability, leg pain and quality of life. METHODS: 165 patients were enrolled; 146 patients with a single level disc herniation (L2 to L5) were randomized: 75 investigational (herniectomy and DIAM) and 71 control (herniectomy alone) treated and followed up for 24 months. RESULTS: Significant improvements overtime (P < 0.001) in both groups but not significantly different between groups for visual analog scale (VAS) back pain at 6 months (investigational -3.97 ± 2.55 vs control-3.37 ± 3.15, P = 0.228) and Oswestry Disability Index (ODI) at 12 months (-38.55 ± 20.10 vs -37.19 ± 22.61, P = 0.719). For both outcomes, there was no statistically significant difference between the groups, at all postoperative time points. Although the enrolment ended before the intended sample size (308 patients) was reached, the number of patients reaching the VAS back pain minimally clinically important difference (MCID) of ≥2.2 at 6 months was higher in the investigational (79.4 % vs control 57.1 %, P = 0.008). These results were sustained throughout 24 months (82.8 vs 64.4 %, P < 0.05). In average, surgical duration (P < 0.001), blood loss (P = 0.029) and skin incision (P < 0.001) in the investigational were 10 min longer, 22.5 ml greater and 2.0 cm wider than control group (median values). Improved tertiary outcomes from BL to 24 mo in both groups (investigational vs control): VAS leg pain (mean decrease -6.41 ± 2.57 to -6.41 vs -5.61 ± to -3.30); improved quality of life (SF-36: 20.68 ± 9.44 vs 16.90 ± 10.74); pain medication reduction: 56.7 vs 47.9 %; return to work: 45.7 vs 38.0 %. Adverse event rates: 68.5 % investigational and 66.2 % control. CONCLUSIONS: This is the first randomized controlled trial to report equivalent efficacy and safety of herniectomy with or without DIAM spinal stabilizing device. Leg pain, back pain and the level of disability were not significantly different between groups; however, number of patients reaching the MCID for back pain was significantly higher in the investigational group at 6 through 24 months.

Delayed hypersensitivity reaction caused by metal-on-metal total disc replacement.

The authors report the case of a 53-year-old woman who underwent placement of a metal-on-metal total disc replacement (TDR) device for the treatment of discogenic back pain. The initial postoperative course was normal, but 2 months after surgery she started to complain of a recurrence of pain and she progressively developed cauda equina syndrome. Radiological and biological findings showed an inflammatory polyneuropathy associated with an epidural mass. A diagnosis of cell-mediated hypersensitivity reaction (Type IV) was made after patch testing showed positive reactions for 1% cobalt chloride and chromium. A decision was made to remove the TDR device and to perform a circumferential fusion. This report is intended to inform the reader that systemic metal release and hypersensitivity reaction are possible complications of metal-on-metal TDR.

Sustained effectiveness of occipital nerve stimulation in drug-resistant chronic cluster headache.

BACKGROUND: Drug-resistant chronic cluster headache (drCCH) is a devastating condition for which various invasive therapeutic procedures have been tempted without any satisfactory effect. Recent studies suggest that occipital nerve stimulation (ONS) could be an efficient preventive treatment of drCCH. OBJECTIVE: We conducted a prospective pilot trial of ONS in 8 subjects suffering from drCCH with encouraging results at 15 months. However, studies on a larger population with a longest follow-up were warranted. METHODS: We recruited 15 patients with drCCH according to the previously published criteria of intractability. They were implanted with suboccipital stimulators on the side of their headache. Long-term follow-up was achieved by questionnaires administered during a headache consultation and/or by phone interviews. RESULTS: Mean follow-up time post surgery is 36.82 months (range 11-64 months). One patient had an immediate post-operative infection of the material. Among the 14 remaining patients, 11 (i.e., ∼80%) have at least a 90% improvement with 60% becoming pain-free for prolonged periods. Two patients did not respond or described mild improvement. Intensity of residual attacks is not modified by ONS. Four patients (29%) were able to reduce their prophylaxis. The major technical problems were battery depletion due to the use of high current intensities (N = 9/14, 64%) and immediate or delayed material infection (N = 3/15, 20%). Significant electrode migration was only seen in 1 patient. Clinical peculiarities during the ONS follow-up period were side shift with infrequent contralateral attacks (N = 5/14, 36%), and/or isolated ipsilateral autonomic attacks without pain (N = 5/14, 36%). Two patients found ONS-related paresthesias unbearable: one had his stimulator removed, and the other switched it off although he was objectively ameliorated. Subjectively, 9 patients are very satisfied by ONS and 3 patients moderately satisfied. Effective stimulation parameters varied between patients. CONCLUSIONS: Our long-term follow-up confirms the efficacy of ONS in drCCH, which remains a safe and well-tolerated technique. The occurrence of contralateral attacks and isolated autonomic attacks in nearly 50% of ONS responders may have therapeutic and pathophysiological implications.

Occipital nerve stimulation for drug-resistant chronic cluster headache: a prospective pilot study.

BACKGROUND: Drug-resistant chronic cluster headache (drCCH) is a devastating disorder for which various destructive procedures have been tried unsuccessfully. Occipital nerve stimulation (ONS) is a new, safe strategy for intractable headaches. We undertook a prospective pilot trial of ONS in drCCH to assess clinical efficacy and pain perception. METHODS: Eight patients with drCCH had a suboccipital neurostimulator implanted on the side of the headache and were asked to record details of frequency, intensity, and symptomatic treatment for their attacks in a diary before and after continuous ONS. To detect changes in cephalic and extracephalic pain processing we measured electrical and pressure pain thresholds and the nociceptive blink reflex. FINDINGS: Two patients were pain free after a follow-up of 16 and 22 months; one of them still had occasional autonomic attacks. Three patients had around a 90% reduction in attack frequency. Two patients, one of whom had had the implant for only 3 months, had improvement of around 40%. Mean follow-up was 15.1 months (SD 9.5, range 3-22). Intensity of attacks tends to decrease earlier than frequency during ONS and, on average, is improved by 50% in remaining attacks. All but one patient were able to substantially reduce their preventive drug treatment. Interruption of ONS by switching off the stimulator or because of an empty battery was followed within days by recurrence and increase of attacks in all improved patients. ONS did not significantly modify pain thresholds. The amplitude of the nociceptive blink reflex increased with longer durations of ONS. There were no serious adverse events. INTERPRETATION: ONS could be an efficient treatment for drCCH and could be safer than deep hypothalamic stimulation. The delay of 2 months or more between implantation and significant clinical improvement suggests that the procedure acts via slow neuromodulatory processes at the level of upper brain stem or diencephalic centres.