Combining Awake Anesthesia with Minimal Invasive Surgery Optimizes Intraoperative Surgical Spinal Cord Stimulation Lead Placement.

Spinal cord stimulation (SCS) is an effective and validated treatment to address chronic refractory neuropathic pain in persistent spinal pain syndrome-type 2 (PSPS-T2) patients. Surgical SCS lead placement is traditionally performed under general anesthesia due to its invasiveness. In parallel, recent works have suggested that awake anesthesia (AA), consisting of target controlled intra-venous anesthesia (TCIVA), could be an interesting tool to optimize lead anatomical placement using patient intra-operative feedback. We hypothesized that combining AA with minimal invasive surgery (MIS) could improve SCS outcomes. The goal of this study was to evaluate SCS lead performance (defined by the area of pain adequately covered by paraesthesia generated via SCS), using an intraoperative objective quantitative mapping tool, and secondarily, to assess pain relief, functional improvement and change in quality of life with a composite score. We analyzed data from a prospective multicenter study (ESTIMET) to compare the outcomes of 115 patients implanted with MIS under AA (MISAA group) or general anesthesia (MISGA group), or by laminectomy under general anesthesia (LGA group). All in all, awake surgery appears to show significantly better performance than general anesthesia in terms of patient pain coverage (65% vs. 34-62%), pain surface (50-76% vs. 50-61%) and pain intensity (65% vs. 35-40%), as well as improved secondary outcomes (quality of life, functional disability and depression). One step further, our results suggest that MISAA combined with intra-operative hypnosis could potentialize patient intraoperative cooperation and could be proposed as a personalized package offered to PSPS-T2 patients eligible for SCS implantation in highly dedicated neuromodulation centers.

Occipital Nerve Stimulation for Refractory Chronic Cluster Headache: A Cost-Effectiveness Study.

INTRODUCTION: Occipital nerve stimulation (ONS) is proposed to treat refractory chronic cluster headache (rCCH), but its cost-effectiveness has not been evaluated, limiting its diffusion and reimbursement. MATERIALS AND METHODS: We performed a before-and-after economic study, from data collected prospectively in a nation-wide registry. We compared the cost-effectiveness of ONS associated with conventional treatment (intervention and postintervention period) to conventional treatment alone (preintervention period) in the same patients. The analysis was conducted on 76 rCCH patients from the French healthcare perspective at three months, then one year by extrapolation. Because of the impact of the disease on patient activity, indirect cost, such as sick leave and disability leave, was assessed second. RESULTS: The average total cost for three months was €7602 higher for the ONS strategy compared to conventional strategy with a gain of 0.07 quality-adjusted life-years (QALY), the incremental cost-effectiveness ratio (ICER) was then €109,676/QALY gained. The average extrapolated total cost for one year was €1344 lower for the ONS strategy (p = 0.5444) with a gain of 0.28 QALY (p < 0.0001), the ICER was then €-4846/QALY gained. The scatter plot of the probabilistic bootstrapping had 80% of the replications in the bottom right-hand quadrant, indicating that the ONS strategy is dominant. The average indirect cost for three months was €377 lower for the ONS strategy (p = 0.1261). DISCUSSION: This ONS cost-effectiveness study highlighted the limitations of a short-time horizon in an economic study that may lead the healthcare authorities to reject an innovative strategy, which is actually cost-effective. One-year extrapolation was the proposed solution to obtain results on which healthcare authorities can base their decisions. CONCLUSION: Considering the burden of rCCH and the efficacy and safety of ONS, the demonstration that ONS is dominant should help its diffusion, validation, and reimbursement by health authorities in this severely disabled population.

Long-Term Efficacy of Occipital Nerve Stimulation for Medically Intractable Cluster Headache.

BACKGROUND: Occipital nerve stimulation (ONS) has been proposed to treat refractory chronic cluster headache (rCCH) but its efficacy has only been showed in small short-term series. OBJECTIVE: To evaluate ONS long-term efficacy in rCCH. METHODS: We studied 105 patients with rCCH, treated by ONS within a multicenter ONS prospective registry. Efficacy was evaluated by frequency, intensity of pain attacks, quality of life (QoL) EuroQol 5 dimensions (EQ5D), functional (Headache Impact Test-6, Migraine Disability Assessment) and emotional (Hospital Anxiety Depression Scale [HAD]) impacts, and medication consumption. RESULTS: At last follow-up (mean 43.8 mo), attack frequency was reduced >50% in 69% of the patients. Mean weekly attack frequency decreased from 22.5 at baseline to 9.9 (P < .001) after ONS. Preventive and abortive medications were significantly decreased. Functional impact, anxiety, and QoL significantly improved after ONS. In excellent responders (59% of the patients), attack frequency decreased by 80% and QoL (EQ5D visual analog scale) dramatically improved from 37.8/100 to 73.2/100. When comparing baseline and 1-yr and last follow-up outcomes, efficacy was sustained over time. In multivariable analysis, low preoperative HAD-depression score was correlated to a higher risk of ONS failure. During the follow-up, 67 patients experienced at least one complication, 29 requiring an additional surgery: infection (6%), lead migration (12%) or fracture (4.5%), hardware dysfunction (8.2%), and local pain (20%). CONCLUSION: Our results showed that long-term efficacy of ONS in CCH was maintained over time. In responders, ONS induced a major reduction of functional and emotional headache-related impacts and a dramatic improvement of QoL. These results obtained in real-life conditions support its use and dissemination in rCCH patients.

How Should we Use Multicolumn Spinal Cord Stimulation to Optimize Back Pain Spatial Neural Targeting? A Prospective, Multicenter, Randomized, Double-Blind, Controlled Trial (ESTIMET Study).

BACKGROUND: Recent studies have highlighted multicolumn spinal cord stimulation (SCS) efficacy, hypothesizing that optimized spatial neural targeting provided by new-generation SCS lead design or its multicolumn programming abilities could represent an opportunity to better address chronic back pain (BP). OBJECTIVE: To compare multicolumn vs. monocolumn programming on clinical outcomes of refractory postoperative chronic BP patients implanted with SCS using multicolumn surgical lead. MATERIALS AND METHODS: Twelve centers included 115 patients in a multicenter, randomized, double-blind, controlled trial. After randomization, leads were programmed using only one or several columns. The primary outcome was change in BP visual analogic scale (VAS) at six months. All patients were then programmed using the full potential of the lead up until 12-months follow-up. RESULTS: At six months, there was no significant difference in clinical outcomes whether the SCS was programmed using a mono or a multicolumn program. At 12 months, in all patients having been receiving multicolumn SCS for at least six months (n = 97), VAS decreases were significant for global pain (45.1%), leg pain (55.8%), and BP (41.5%) compared with baseline (p < 0.0001). CONCLUSION: The ESTIMET study confirms the significant benefit experienced on chronic BP by patients implanted with multicolumn SCS, independently from multicolumn lead programming. These good clinical outcomes might result from the specific architecture of the multicolumn lead, giving the opportunity to select initially the best column on a multicolumn grid and to optimize neural targeting with low-energy requirements. However, involving more columns than one does not appear necessary, once initial spatial targeting of the "sweet spot" has been achieved. Our findings suggest that this spatial concept could also be transposed to cylindrical leads, which have drastically improved their capability to shape the electrical field, and might be combined with temporal resolution using SCS new modalities.

Effects of tibial nerve neurotomy on posture and gait in stroke patients: A focus on patient-perceived benefits in daily life.

OBJECTIVE: To evaluate the objective and subjective functional effectiveness of tibial nerve neurotomy (TNN) in post-stroke spastic equinovarus foot (SEF). METHODS: In an open study, 23 hemiplegic patients were assessed immediately before TNN and then 5months after TNN. The main outcome measure was the Lower Limb Function Assessment Scale (LL-FAS), which provided an ecologic assessment of impairments in standing and walking (i.e. kinematic abnormalities) and their impacts on activities of daily living. Patients were also assessed for global clinical impression of change, fear of falling, neuromotor impairments, spatiotemporal and video gait parameters and walking capacities. RESULTS: TNN had a very marked effect on the level of spasticity and the range of motion in dorsiflexion (p<10(-3)). These changes resulted in better foot positioning when standing and walking (particularly in stance), which was perceived very favorably by the patients. There was a clear, patient-perceived improvement in activities performed when standing and walking (LL-FAS (p<0.01)), the global clinical impression of change (p<10(-3)) and the fear of falling (p=0.022) that was not revealed by conventional, objective measurements (New Functional Ambulation Classification, Rivermead Mobility Index). CONCLUSION: TNN is an effective treatment for post-stroke SEF; it is associated with a patient-reported improvement in standing and walking abilities during activities of daily living. Further research must now assess the long-term subjective efficacy of TNN.

Ziconotide adverse events in patients with cancer pain: a multicenter observational study of a slow titration, multidrug protocol.

BACKGROUND: Ziconotide is a new analgesic agent administered intrathecally. It is challenging to use and can induce several and sometimes serious adverse events. A low initial dosage followed by slow titration may reduce serious adverse events. OBJECTIVE: To determine whether a low starting dosage of ziconotide, followed by slow titration, decreases the incidence of major adverse events associated with ziconotide when used for intractable cancer pain. STUDY DESIGN: Observational cohort study. SETTING: Three French cancer centers. METHODS: Patients with incurable cancer causing chronic pain rated above 6/10 on a numerical scale while receiving high-dose opioid therapy (more than 200 mg/d of oral morphine equivalent) and/or exhibiting severe opioid-related adverse events received intrathecal infusions of ziconotide combined with morphine, ropivacaine, and clonidine. RESULTS: Seventy-seven patients were included. Adverse events were recorded in 57% of them; moderate adverse events occurred in 51%. Adverse events required treatment discontinuation in 7 (9%) including 5 (6%) for whom a causal role for ziconotide was highly likely; among them 4 (5%) were serious. All patients experienced a significant and lasting decrease in pain intensity (by 48%) in response to intrathecal analgesic therapy that included ziconotide. LIMITATIONS: Limitations include the nonrandomized, observational nature of the study. Determining the relative contributions of each drug to adverse events was difficult, and some of the adverse events manifested as clinical symptoms of a subjective nature. CONCLUSIONS: The rates of minor and moderate adverse events were consistent with previous reports. However, the rate of serious adverse events was substantially lower. Our study confirms the efficacy of intrathecal analgesia with ziconotide for relieving refractory cancer pain. These results indicate that multimodal intrathecal analgesia in patients with cancer pain should include ziconotide from the outset in order to provide time for subsequent slow titration.

Long-term effect of tibial nerve neurotomy in stroke patients with lower limb spasticity.

OBJECTIVES: We investigated the long-term effects and predictive indices of efficacy of tibial nerve neurotomy in a large series of patients with post-stroke hemiplegia. METHODS: Fifty-one patients were prospectively included, who showed disabling lower limb deformity (equinus, varus, clawing toes). The motor branches of the tibial nerve were selected according to the type of deformity, and partially resected at the posterior part of the calf. Patients were regularly assessed, before surgery and from the third month to the second year post surgery, for spasticity (primary outcome measure), motor control, range of active and passive movements, balance, walk, gait parameters, Rivermead Motor Assessment (RMA), subjective improvement and satisfaction. RESULTS: Neurotomy definitely reduced spasticity and improved motor control on antagonist muscles, while improving balance, walk, and the RMA. These effects were clearly perceived in daily living. A discrete decline was at times observed at 2 years. Functional improvement was greater in patients more severely impaired. Side effects, consisting in sensory disorders, were observed following neurotomy of the motor fascicles of the flexor digitorum longus. CONCLUSIONS: Tibial nerve neurotomy showed great and lasting effects, and can be proposed to improve walking and balance in stroke patients with disabling lower limb deformity.