Incidence and Risk Factors for Spinal Cord Stimulator Lead Migration With or Without Loss of Efficacy: A Retrospective Review of 91 Consecutive Thoracic Lead Implants.

OBJECTIVE: Lead migration after spinal cord stimulator (SCS) implant is a commonly reported complication and the most common reason for revision surgery in cases of loss of efficacy. The primary aims of this study are to describe the incidence and degree of lead migration in the subacute postoperative period after SCS implant and to report potential risk factors for lead migration. MATERIALS AND METHODS: We performed a retrospective chart review of all patients at a single academic center who received an SCS implant from January 1, 2020, to December 31, 2020. Information on patient (age, sex, weight, and height) and operative factors (device manufacturer, epidural access level and method, and implantable pulse generator location) were extracted from medical records. Intraoperative imaging was compared to subacute follow-up imaging obtained less than 20 days postimplant to measure lead migration distance. Regression models were fitted to determine associations between lead migration distance and potential clinical risk factors. RESULTS: A total of 91 cases (182 leads) were included in the study. Within 20 days of implantation, 88.5% of leads had migrated (86.3% caudal and 2.2% cephalad). Mean migration distance for leads with caudal migration only was 12.34 ± 12.19 mm based on anteroposterior radiographs and 16.95 ± 15.68 mm on lateral radiographs. There was an association of greater caudal lead migration as patient body mass index increased (ß-coefficient 0.07 [95% confidence interval 0.01-0.13], p = 0.031). Within the entire cohort, one patient (1.1%) required lead revision for loss of efficacy. CONCLUSIONS: In the subacute postoperative period after SCS implant, the majority of SCS leads migrated caudally with an average of two lead contacts. Knowledge of this expected migration and risk factors can better inform implanting physicians intraoperatively when deciding final lead placement location. The finding of high likelihood of caudal lead migration in the subacute postoperative period brings the need for a well-designed prospective study to the forefront of our field. This will allow implanting providers to make well-informed decisions for intraoperative lead placement.

The Role of Vancomycin Powder During Spinal Cord Stimulator Implantation: A Case Series and Review of the Literature.

OBJECTIVE: We examined the role of intrawound vancomycin powder as prophylaxis against postoperative surgical site infection (SSI) after spinal cord stimulator (SCS) implantation. METHODS: We performed a retrospective analysis of 153 consecutive patients who had undergone permanent SCS implantation surgery via open laminectomy between 2014 and 2020. We queried the patients' medical records for patient age, sex, relevant medical history, and whether intrawound vancomycin had been administered. We compared the rates of SSI (primary outcome) and seroma (secondary outcome) within 3 months after surgery between the vancomycin and no-vancomycin groups. Finally, we conducted multivariable logistic regression analyses to identify independent predictors of postoperative SSI or seroma. RESULTS: Of the 153 patients, 59% were women, and the average age was 65.4 years. Overall, 3 patients (2%) had developed an SSI: 2 (methicillin-resistant Staphylococcus aureus, Klebsiella) in the vancomycin group and 1 (methicillin-sensitive Staphylococcus aureus) in the no-vancomycin group. This difference in SSI rate between the 2 groups was insignificant (P = 0.73). Three seromas, all in the no-vancomycin group, accounted for a statistically significant difference in seroma formation between the 2 groups (P = 0.04). Multivariate logistic regression failed to identify any perioperative characteristics as independent predictors of postoperative SSI or seroma. CONCLUSIONS: Our experience suggests open laminectomy for SCS implantation surgery can be performed with a low postoperative SSI rate, with or without the use of powdered vancomycin. We found no evidence suggesting that the use of powdered vancomycin is unsafe or related to postoperative seroma formation. We failed to draw any definitive conclusions regarding its efficacy, despite referencing the largest single case series of SCS implantation to date.

Placement of Surgical Spinal Cord Stimulation Leads Using Spinal Process Splitting Laminotomy: Technical Note.

OBJECTIVE: Spinal cord stimulation has become an established method within the therapy of chronic pain allowing for significant pain relief. Surgical leads usually must be implanted via a surgical procedure involving unilateral or bilateral muscle detachment and partial laminectomy. METHODS: We present the application of a novel minimal invasive microsurgical approach for lead placement, which combines the beneficial advantages of anatomic midline lead placement while preserving the midline structures, avoiding muscle detachments, and thus ensuring spinal stability: spinal process splitting laminotomy. CONCLUSIONS: The spinal process splitting laminotomy technique can be successfully applied to introduce the surgical leads for spinal cord stimulation.

Lead Migration in Neuromodulation.

We describe a simple technique of securing surgically implanted leads for spinal cord (SCS), dorsal root ganglion (DRG) and occipital nerve stimulation (ONS), for both primary surgical implantation and correcting lead migration. This technique could also be adapted for securing percutaneously implanted leads. Thirty-nine patients underwent neurosurgical implantation of SCS, DRG, and ONS devices utilizing titanium mini-plates to obtain secure anchorage of leads to adjacent laminae close to their exit point from the epidural space, thereby minimizing the risk of further lead migration or electrode displacement. There were no cases of primary or recurrent lead migration in any patient undergoing lead placement using mini-plate anchorage. The technique appears to offer a reliable means of preventing post-operative lead migration in a variety of spinal and extra-cranial neuromodulation implants.

Efficacy of different spinal cord stimulation paradigms for the treatment of chronic neuropathic pain (PARS-trial): study protocol for a double-blinded, randomized, and placebo-controlled crossover trial.

BACKGROUND: Spinal cord stimulation (SCS) is an effective method to treat neuropathic pain; however, it is challenging to compare different stimulation modalities in an individual patient, and thus, it is largely unknown which of the many available SCS modalities is most effective. Specifically, electrodes leading out through the skin would have to be consecutively connected to different, incompatible SCS devices and be tested over a time period of several weeks or even months. The risk of wound infections for such a study would be unacceptably high and blinding of the trial difficult. The PARS-trial seizes the capacity of a new type of wireless SCS device, which enables a blinded and systematic intra-patient comparison of different SCS modalities over extended time periods and without increasing wound infection rates. METHODS: The PARS-trial is designed as a double-blinded, randomized, and placebo-controlled multi-center crossover study. It will compare the clinical effectiveness of the three most relevant SCS paradigms in individual patients. The trial will recruit 60 patients suffering from intractable neuropathic pain of the lower extremities, who have been considered for SCS therapy and were already implanted with a wireless SCS device prior to study participation. Over a time period of 35 days, patients will be treated consecutively with three different SCS paradigms ("burst," "1 kHz," and "1.499 kHz") and placebo stimulation. Each SCS paradigm will be applied for 5 days with a washout period of 70 h between stimulation cycles. The primary endpoint of the study is the level of pain self-assessment on the visual analogue scale after 5 days of SCS. Secondary, exploratory endpoints include self-assessment of pain quality (as determined by painDETECT questionnaire), quality of life (as determined by Quality of Life EQ-5D-5L questionnaire), anxiety perception (as determined by the Hospital Anxiety and Depression Scale), and physical restriction (as determined by the Oswestry Disability Index). DISCUSSION: Combining paresthesia-free SCS modalities with wireless SCS offers a unique opportunity for a blinded and systematic comparison of different SCS modalities in individual patients. This trial will advance our understanding of the clinical effectiveness of the most relevant SCS paradigms. TRIAL REGISTRATION: German Clinical Trials Register, DRKS00018929 . Registered on 14 January 2020.

Recruitment of upper-limb motoneurons with epidural electrical stimulation of the cervical spinal cord.

Epidural electrical stimulation (EES) of lumbosacral sensorimotor circuits improves leg motor control in animals and humans with spinal cord injury (SCI). Upper-limb motor control involves similar circuits, located in the cervical spinal cord, suggesting that EES could also improve arm and hand movements after quadriplegia. However, the ability of cervical EES to selectively modulate specific upper-limb motor nuclei remains unclear. Here, we combined a computational model of the cervical spinal cord with experiments in macaque monkeys to explore the mechanisms of upper-limb motoneuron recruitment with EES and characterize the selectivity of cervical interfaces. We show that lateral electrodes produce a segmental recruitment of arm motoneurons mediated by the direct activation of sensory afferents, and that muscle responses to EES are modulated during movement. Intraoperative recordings suggested similar properties in humans at rest. These modelling and experimental results can be applied for the development of neurotechnologies designed for the improvement of arm and hand control in humans with quadriplegia.

Retrospective analysis on the effect of spinal cord stimulation on opioid consumption.

Aim: Spinal cord stimulation (SCS) is used to clinically manage and/or treat several chronic pain etiologies. A limited amount is known about the influence on patients' use of opioid pain medication. This retrospective analysis evaluated SCS effect on opioid consumption in patients presenting with chronic pain conditions. Materials & methods: Sixty-seven patients underwent a temporary trial device, permanent implant or both. Patients were divided for assessment based on the nature of their procedure(s). Primary outcome was change in morphine equivalent dose (MED), ascertained from preoperative and postoperative medication reports. Results: Postoperative MED was significantly lower in patients who received some form of neuromodulation therapy. Pretrial patients reported an average MED of 41.01 ± 10.23 mg per day while post-trial patients reported an average of 13.30 ± 5.34 mg per day (p < 0.001). Pre-implant patients reported an average MED of 39.14 ± 13.52 mg per day while post-implant patients reported an average MED of 20.23 ± 9.01 mg per day (p < 0.001). There were no significant differences between pre-trial and pre-implant MED, nor between post-trial and post-implant MED. Of the 42 study subjects who reported some amount of pre-intervention opioid use, 78.57% indicated a lower MED (n = 33; p < 0.001), 16.67% indicated no change (n = 7) and 4.76% (n = 2) indicated a higher MED, following intervention. Moreover, SCS therapy resulted in a 26.83% reduction (p < 0.001) in the number of patients with MED >50 mg per day. Conclusion: Spinal cord stimulation may reduce opioid use when implemented appropriately. Neuromodulation may represent alternative therapy for alleviating chronic pain which may avoid a number of deleterious side effects commonly associated with opioid consumption.

Effects of Lower Thoracic Spinal Cord Stimulation on Bowel Management in Individuals With Spinal Cord Injury.

OBJECTIVE: To systematically determine whether use of the spinal cord stimulation (SCS) system to restore cough may improve bowel management (BM) in individuals with spinal cord injury (SCI). DESIGN: Experimental studies (clinical trial). SETTING: Inpatient hospital setting for electrode insertion; outpatient setting for measurement of respiratory pressures; home setting for application of SCS. PARTICIPANTS: Participants (N=5) with cervical SCI. INTERVENTION: A fully implantable SCS cough system was surgically placed in each subject. SCS was applied at home, 2-3 times/d, on a chronic basis, every time bowel regimen was performed and as needed for secretion management. Stimulus parameters were set at values resulting in near maximum airway pressure generation, which was used as an index of expiratory muscle strength. Participants also used SCS during their bowel routine. MAIN OUTCOME MEASURES: Airway pressure generation achieved with SCS. Weekly completion of Bowel Routine Log including BM time, mechanical measures, and medications used. RESULTS: Mean pressure during spontaneous efforts was 30±8 cmH2O. After a period of reconditioning, SCS resulted in pressure of 146±21 cmH2O. The time required for BM routines was reduced from 118±34 minutes to 18±2 minutes (P<.05) and was directly related to the magnitude of pressure development during SCS. Mechanical methods for BM were completely eliminated in 4 patients. No patients experienced fecal incontinence as result of SCS. Each participant also reported marked overall improvement associated with BM. CONCLUSIONS: Our results of this pilot study suggest that SCS to restore cough may be a useful method to improve BM and life quality for both patients with SCI and their caregivers. Our results indicate that the improvement in BM is secondary to restoration of intra-abdominal pressure development.

Pain relief outcomes using an SCS device capable of delivering combination therapy with advanced waveforms and field shapes.

BACKGROUND: Given the range of subjective experiences reported by patients with chronic pain, Spinal Cord Stimulation (SCS) systems designed for tailored delivery of analgesic therapy may help improve treatment effectiveness and satisfaction. RESEARCH DESIGN AND METHODS: This case-series evaluated 420 patients with chronic back and/or leg pain implanted with an SCS device capable of sequential or simultaneous delivery of neurostimulation (i.e. combination therapy) as well as multiple waveforms and/or field shapes. Following implantation, an array of standard programs (e.g. paresthesia-based SCS), and a custom set of sub-perception programs were provided per patient feedback. Pain scores (Numeric Rating Scale, NRS) were collected at baseline and during follow-up. RESULTS: In this multicenter, observational series (n = 420, 53.1% female; Age: 64.2 ± 13.4 years), a mean overall pain score of 7.2 ± 1.8 (SD) was reported pre-trial (Baseline). At a mean follow-up duration of 208 ± 200 (SD) days, the mean overall pain score reduced to 2.4 (p < 0.0001). Overall pain was reduced by 5.1 ± 2.4 and 4.5 ± 2.4 points (NRS) at 3-months (N = 256) and at 12-months post-implant (N = 122) respectively (p < 0.0001). CONCLUSIONS: These results suggest that highly 'customizable' SCS approaches may allow for highly effective pain relief within the real-world clinical setting.

Bipolar transcutaneous spinal stimulation evokes short-latency reflex responses in human lower limbs alike standard unipolar electrode configuration.

Noninvasive electrical stimulation targeting the posterior lumbosacral roots has been applied recently in reflexes studies and as a neuromodulation intervention for modifying spinal cord circuitry after an injury. Here, we characterized short-latency responses evoked by four bipolar electrode configurations placed longitudinally over the spinal column at different vertebral levels from L1 to T9. They were compared with the responses evoked by the standard unipolar (aka monopolar) electrode configuration (cathode at T11/12, anode over the abdominal wall). Short-latency responses were recorded in the rectus femoris, medial hamstrings, tibialis anterior, and soleus muscles, bilaterally, in 11 neurologically intact participants. The response recruitment characteristics (maximal amplitude, motor threshold) and amplitude-matched onset latencies and paired-pulse suppression (35-ms interstimulus interval) were assessed with 1-ms current-controlled pulses at intensities up to 100 mA. The results showed that short-latency responses can be elicited with all bipolar electrode configurations. However, only with the cathode at T11/12 and the anode 10 cm cranially (∼T9), the maximum response amplitudes were statistical equivalent (P < 0.05) in the medial hamstrings, tibialis anterior, and soleus but not the rectus femoris, whereas motor thresholds were not significantly different across all muscles. The onset latency and paired-pulse suppression were also not significantly different across the tested electrode configurations, thereby confirming the reflex nature of the bipolar short-latency responses. We conclude that the bipolar configuration (cathode T11/12, anode ∼T9) produces reflex responses that are ostensibly similar to those evoked by the standard unipolar configuration. This provides an alternative approach for neuromodulation intervention.NEW & NOTEWORTHY Transcutaneous spinal stimulation with the identified bipolar electrode configuration may offer several advantages for neuromodulation interventions over commonly used unipolar configurations: there are no associated abdominal contractions, which improves the participant's comfort; additional dermatomes are not stimulated as when the anode is over the abdominal wall or iliac crest, which may have unwanted effects; and, due to a more localized electrical field, the bipolar configuration offers the possibility of targeting cord segments more selectively.

Sustainable Effects of 8-Year Intermittent Spinal Cord Stimulation in a Patient with Thalamic Post-Stroke Pain.

BACKGROUND: Central post-stroke pain (CPSP) is a central neuropathic pain syndrome secondary to a cerebrovascular accident. CPSP treatment usually begins with medication; however, this is associated with inadequate pain relief and adverse effects. Neurostimulation therapies, including spinal cord stimulation (SCS), have been developed for improved pain relief. We report a patient with thalamic pain who underwent 8-year cervical SCS in an intermittent mode. CASE DESCRIPTION: A 71-year-old man presented with left thalamic stroke that caused persistent allodynia and "pricking" sensations at right-side extremities. The pain did not respond well to several pain therapies, including medication, acupuncture, and nerve-blocking anesthesia. Subsequently, the severe and refractory pain caused dystonia in his right hand and seriously hindered recovery and rehabilitation of stroke sequelae. Further, the pain induced depression and severe anxiety mood status and had an effect on his functional activities of life. After SCS device implantation, the patient received intermittent stimulation with 90 minutes on/30 minutes off. A significant decrease in the patient's pain was observed with no serious side effects. After subtle programming of the implantable pulse generator, a significant improvement of his dystonia and affective mood was observed. Intermittent SCS allowed for persistent stimulation for 8 years. Taken together, this intervention allowed for an acceptable improvement of his functional quality of life. CONCLUSIONS: Our findings indicate that SCS is safe and efficacious for CPSP, including thalamic stroke pain. Long-term intermittent stimulation can preserve implantable pulse generator battery life and achieve sustained improvement of a patient's pain, movement, and affective mood status.

Spinal cord stimulation for the treatment of neuropathic pain: expert opinion and 5-year outlook.

INTRODUCTION: Spinal cord stimulation (SCS) is an effective treatment for chronic, intractable neuropathic pain. There have been relatively few high-level studies that suggest its unequivocal use. The decay of stimulation efficacy over time have opened opportunity for the entrance of new pulse trains and waveforms. AREAS COVERED: In this state-of-the-art review, we focused on many of the major studies published in the last 10 years that were considered level one evidence. A retrospective narrative approach was taken to conceptualize foundation studies as they pertain to current evidence. A special focus was taken on reported safety outcomes in comparison to foundation studies especially as they pertain to our 5-year outlook on the use of spinal cord stimulation. EXPERT OPINION: We find there are still significant limitations in the body of reviewed evidence and suggest that long-term data beyond 24 months are lacking in the literature. In addition, adverse event rates, device explantation rates and the sham effect looms as important concepts to address in the future in spite of the existing novel stimulation paradigms.

Longevity and Utilization Cost of Rechargeable and Non-Rechargeable Spinal Cord Stimulation Implants: A Comparative Study.

INTRODUCTION: Despite major advancements in features and capabilities of the implantable pulse generator (IPG), real-life longevity and cost-effectiveness studies to guide pain specialists to make the appropriate choice between rechargeable and non-rechargeable IPG are limited. Our study aimed to compare the longevity and cost effectiveness of rechargeable vs. non-rechargeable IPG and SCS systems. METHODS: Data were collected for all SCS implantations performed between 1994 and 2018. The primary goal was to determine IPG longevity, defined as the time interval between IPG implantation and elective replacement due to IPG end of life (EOL). On the other hand, SCS system longevity was defined as the time between SCS implantation and its removal or revision for any reason other than IPG EOL. Kaplan-Meier and log-rank tests were used to assess IPG and SCS system longevities. Cost analysis was performed for cost effectiveness. RESULTS: The median IPG longevity was significantly higher for rechargeable SCS devices than for non-rechargeable SCS devices (7.20 years and 3.68 years, respectively). The median cost per day was similar for both IPGs, $13.90 and $13.81 for non-rechargeable and rechargeable, respectively. The median cost for SCS systems was higher for the rechargeable group ($60.70) compared with the non-rechargeable group ($31.38). CONCLUSIONS: Rechargeable IPG had increased longevity compared to their non-rechargeable counterparts, yet there was no significant difference in the actual longevity due to premature revisions or explantations between both SCS systems. Furthermore, non-rechargeable SCS systems were found to be the more cost-effective option when compared with rechargeable SCS systems.

Device profile of the Proclaim XR neurostimulation system for the treatment of chronic pain: an overview of its safety and efficacy.

INTRODUCTION: Spinal cord stimulation is becoming an increasingly used modality for the treatment of chronic pain. The Proclaim XR implantable pulse generator (IPG) is a novel device designed to supply low-dose BurstDR stimulation in a primary cell battery guaranteed to last 5-10 years with appropriate programming. AREAS COVERED: BurstDR stimulation involves specifically delivered pockets of electrical energy coupled with a passive recharge mechanism to mimic the body's natural neuronal activity. MEDLINE databases were searched with a date range from 2010 to 2020, and a review of the evidence for low amplitude BurstDR stimulation, which led to FDA approval of the Proclaim XR system, is provided. In addition, we will review the safety and precautionary measures involved with this device. EXPERT OPINION: The Proclaim XR IPG is the newest and most advanced device in SCS technology. It is designed to meet the preferences of patients by providing burst low amplitude intermittent dosing in a recharge-free manner and a guaranteed 5-10 year battery life.

Focused Ultrasound Thalamotomy with Dentato-Rubro-Thalamic Tractography in Patients with Spinal Cord Stimulators and Cardiac Pacemakers.

Magnetic resonance image-guided high-intensity focused ultrasound (MRgFUS)-based thermal ablation of the ventral intermediate nucleus of the thalamus (VIM) is a minimally invasive treatment modality for essential tremor (ET). Dentato-rubro-thalamic tractography (DRTT) is becoming increasingly popular for direct targeting of the presumed VIM ablation focus. It is currently unclear if patients with implanted pulse generators (IPGs) can safely undergo MRgFUS ablation and reliably acquire DRTT suitable for direct targeting. We present an 80-year-old male with a spinal cord stimulator (SCS) and an 88-year-old male with a cardiac pacemaker who both underwent MRgFUS for medically refractory ET. Clinical outcomes were measured using the Clinical Rating Scale for Tremor (CRST). DRTT was successfully created and imaging parameter adjustments did not result in any delay in procedural time in either case. In the first case, 7 therapeutic sonications were delivered. The patient improved immediately and durably with a 90% CRST-disability improvement at 6-week follow-up. In our second case, 6 therapeutic sonications were delivered with durable, 75% CRST-disability improvement at 6 weeks. These are the first cases of MRgFUS thalamotomy in patients with IPGs. DRTT targeting and MRgFUS-based thermal ablation can be safely performed in these patients using a 1.5-T MRI.

Managing acute cancer pain.

Cancer-related pain is an ongoing concern for patients and families. Clinicians should include pain management or palliative care specialists who have advanced knowledge in pharmacotherapy and who have the ability to perform interventional procedures to help alleviate patients' pain and reduce opioid use. This article discusses available interventions for patients with cancer pain.

Spinal Cord Stimulation with Surgical Lead Improves Pain and Gait in Parkinson's Disease after a Dislocation of Percutaneous Lead: A Case Report.

Spinal cord stimulation (SCS) is receiving increasing interests for treating pain and gait disorders in patients with Parkinson's disease (PD). In an SCS study, it is hard to apply a double-blind approach, especially at low frequencies, as the stimulation normally induces paresthesia which can be perceived by the patient. We herein demonstrate a case treated with SCS in which a blinding design was accomplished by an accidental dislocation of a stimulation lead. A 73-year-old man with PD was admitted to our hospital because of relapsed low back pain. This was due to the dislocation of a previously implanted SCS lead, which caused a decrease in its effectiveness in alleviating pain (from 81 to 43% measured by King's Parkinson's Disease Pain Scale) and improving gait (from 35 to 28% measured by the timed up and go test). A second SCS surgery using a paddle lead solved this problem, with improvements in pain and gait rebounded to 81 and 45%. In this case, the paresthesia induced by SCS (using either a paddle lead or percutaneous leads) was below the threshold of perception when the patient was sitting and standing, and a dislocation of one previously implanted percutaneous lead did not cause evident changes in his sensation of paresthesia. At last follow-up, the patient's quality of life had improved by 40% as measured by the 8-item Parkinson's Disease questionnaire (PDQ-8). This study could serve partly as a proof that low-frequency SCS is effective in improving pain as well as gait problems in PD patients, which was unlikely a result of a placebo effect.

Stimulus outputs induced by subdural electrodes on the cervical spinal cord in monkeys.

OBJECTIVE: Spinal stimulation is a promising method for restoring the function of paralyzed limbs following neurological damage to descending pathways. The present study examined the forelimb movements and muscle responses evoked by subdural spinal stimulation of the cervical cord in sedated monkeys or during an arm-reaching task. APPROACH: We chronically implanted a platinum subdural electrode array with eight channels over the dorsal-lateral aspect of the cervical enlargement. The electrodes had a diameter of 1 mm and an inter-electrode center-to-center distance of 3 mm. Subdural spinal micro-stimulation was delivered at sites while the monkeys were sedated or performed arm-reaching movements. MAIN RESULTS: The evoked movements clearly showed the somatotopic map of the output sites; the electrodes located on the rostral cervical cord tended to induce movements of the proximal arm, whereas the caudal electrodes tended to induce movements of the distal joints, such as the wrist and digits. To document the muscle responses evoked by subdural spinal stimulation, stimulus-triggered averages of rectified electromyograms were compiled when the monkeys performed an arm-reaching task or were sedated. Under sedation, evoked facilitative muscle responses were observed in vicinity muscles. In contrast, during the task, stimulation evoked facilitative or suppressive responses in multiple muscles, including those located on proximal and distal joints, while somatotopy became blurred under sedation. Furthermore, stimulation during tasks activated synergistic muscle groups. For example, stimuli strongly facilitated finger extensor muscles, but suppressed the antagonist muscles. SIGNIFICANCE: These dynamic changes in muscle representation by subdural cervical spinal stimulation between sedated and awake states help our understanding of the nature of spinal circuits and will facilitate the development of neuroprosthetic technology to regain motor function after neural damage to the descending pathways.

Percutaneously Inserted Unilateral Lead Migration Salvaged with a Paddle Electrode.

INTRODUCTION: Lead migration has been regarded as a frequent complication after percutaneous spinal cord stimulation (SCS). Thus far, repeated reinsertion of leads or replacement of paddle electrodes after removing percutaneous leads has been performed, but a salvage surgical technique using the remaining electrode has not been reported. Here, we describe a case in which unilateral lead migration was successfully treated with the insertion of a paddle electrode. CASE SUMMARY: A 44-year-old male paraplegic patient with chronic neuropathic pain in the right leg and low back for 7 years underwent a percutaneous spinal cord stimulation procedure 5 times over 2 years because of repeated unilateral lead migration. The left lead underwent repeated migration and was difficult to reinsert due to epidural adhesion. After confirming the position and stimulation area of the remaining lead, we decided to insert another paddle electrode beside the remaining lead. We performed a T10 laminotomy and inserted a paddle electrode on the right side, using it in combination with the previous left lead. After surgery, the patient was satisfied with a wide coverage area. DISCUSSION: We recommend salvage additional paddle electrode insertion rather than removing both leads during revision SCS. This surgical method increases the possibility of covering the dorsal column (DC) of the spinal cord, is cost effective, and decreases the possibility of failing to cover dorsal column using the paddle electrode during open surgery because the remaining lead's position and stimulation area guide the insertion of the additional paddle lead.