Smaller thoracic canal diameters are associated with thoracic radiculopathy and abdominal pain after spinal cord stimulator paddle lead placement.

INTRODUCTION: It is not uncommon for patients to experience postoperative neurologic deficit, thoracic radiculopathy, abdominal pain, or lower extremity paresthesia after the implantation of thoracic spinal cord stimulator (SCS) paddle leads. Smaller thoracic canal diameters have previously been associated with postoperative neurologic deficits. OBJECTIVE: This imaging study examined whether postoperative SCS neurologic complaints other than neurologic deficit may be correlated with thoracic spinal canal diameter. METHODS: Patients who underwent thoracic laminotomy for SCS paddle lead placement between January 2018 and March 2023 were identified. Preoperative thoracic canal diameter was measured on MRI or CT imaging in the sagittal plane from T5/6 to T11/12. The canal diameters of patients with and without new postoperative neurologic complaints were compared. RESULTS: Two hundred forty-six patients underwent thoracic laminotomy for SCS paddle lead placement. Thoracic radiculopathy, abdominal pain, and lower extremity paresthesia occurred in 3.7% (9/246), 2.8% (7/246), and 2.0% (5/246) patients, respectively. The mean canal diameter for patients without neurologic complaint, thoracic radiculopathy, abdominal pain, and lower extremity paresthesia was 13.1 mm, 12.0 mm (p < 0.0001), 12.1 mm (p < 0.01), and 12.8 mm (p = 0.365), respectively. CONCLUSION: A smaller thoracic canal diameter is associated with postoperative thoracic radiculopathy and abdominal pain. We believe that surgical planning to create adequate space for SCS leads is critical in preventing postoperative neurologic complaints of deficit, thoracic radiculopathy, and abdominal pain.

Biportal Endoscopic Spinal Cord Stimulation Paddle Lead Implantation: Technical Note and Preliminary Clinical Results.

OBJECTIVE: This study aims to elucidate a novel, minimally invasive surgical technique using a biportal endoscope for the implantation of spinal cord stimulation (SCS) paddle leads and to report the preliminary results of its clinical application. MATERIALS AND METHODS: The perioperative data of patients who underwent the biportal endoscopic SCS paddle lead implantation in our department were collected; the surgical procedure was delineated, and the clinical outcomes were assessed. RESULTS: From February 2022 to December 2023, six patients underwent biportal endoscopic SCS paddle lead implantation. The median follow-up time was nine months (range one to three months). The median intraoperative blood loss was 30 mL (range 25-50 mL), and the median operative time was 87.5 minutes (range 75-110 minutes). One patient experienced severe neck pain during the operation, whereas the other five patients experienced no surgical complications. One patient was found to have a slight lead migration three months after surgery, which did not affect the therapeutic effect. The median visual analogue scale (VAS) of the surgical area was 0.5 (range 0-2), 2.5 (range 1-4), and 0.5 (range 0-1) during the operation and one day and one week after the operation, respectively. The median VAS of the six patients' primary disease was 8 (range 7-9) before surgery and 2.5 (range 1-4) at the last postoperative follow-up (pain reduction ≥50%). CONCLUSION: Paddle lead systems for SCS can be implanted successfully using a biportal endoscopic technique.

Spinal Cord Stimulation Trial Electrodes Rapidly Produce Epidural Scarring, Impeding Surgical Paddle Lead Placement.

OBJECTIVES: After a successful percutaneous cylindrical electrode five-to-seven-day trial of spinal cord stimulation, subsequent permanent surgical paddle lead (SPL) placement can be impeded by epidural scar induced by the trial leads (TLs). Our goal was to determine whether a delay between TL and subsequent SPL placement provokes enhanced epidural scarring with an increased need for laminotomy extension required for scar removal for optimal SPL placement. MATERIALS AND METHODS: Using a prospectively maintained data base, a single-facility/surgeon retrospective study identified 261 patients with newly placed thoracolumbar SPLs from June 2013 to November 2023. Data were obtained from the patients' charts, including, but not limited to, timing between TL and SPL, operative time, and need for extension of laminotomy. RESULTS: We found that the need for laminotomy extension due to TL epidural scarring and longer operative times was not required in our patients if the SPL was placed within ten days of placement of the TL (0/26), leading to shorter operative times in those with SPL placed after ten days (122.42 ± 10.72 minutes vs 140.75 ± 4.72 minutes; p = 0.005). We found no association with other medical comorbidities that may be confounding factors leading to epidural scarring/extension of laminotomy or association with level of SPL placement, size of the spinal canal, or indication for SPL placement. CONCLUSIONS: TL placement leads to scarring in the epidural space that appears to mature after ten days of its placement. In approximately 34% of patients, this leads to prolonged operative time owing to the need for extension of laminotomy and subsequent clearing of epidural scar for optimal SPL placement.

Analysis of spinal canal diameter in the placement of thoracic spinal cord stimulator paddle leads.

BACKGROUND: Neurologic deficit is known as a rare complication of thoracic spinal cord stimulator (SCS) paddle lead implantation, but many believe its incidence after SCS paddle lead placement is under-reported. It is possible that imaging characteristics may be used to help predict safe paddle lead placement. OBJECTIVE: This imaging study was undertaken to determine the minimum canal diameter required for safe paddle lead placement. METHODS: Patients who underwent thoracic laminotomy for new SCS paddle lead placement from January 2018 to March 2023 were identified retrospectively. Preoperative thoracic canal diameter was measured in the sagittal plane perpendicular to the disc space from T5/6 to T11/12. These thoracic levels were chosen because they span the most common levels targeted for SCS placement. Patients with and without new neurologic deficits were compared using a Mann-Whitney U-test. RESULTS: Of 185 patients initially identified, 180 had thoracic imaging available for review. One (0.5%) and 2 (1.1%) of 185 patients complained of permanent and transient neurologic deficit after thoracic SCS placement, respectively. Patients with neurologic deficits had average canal diameters of <11 mm. The average canal diameter of patients with and without neurologic deficits was 10.2 mm (range 6.1-12.9 mm) and 13.0 mm (range 5.9-20.2), respectively (p < 0.0001). CONCLUSION: Postoperative neurologic deficit is an uncommon complication after thoracic laminotomy for SCS paddle lead placement. The authors recommend ensuring a starting thoracic canal diameter of at least 12 mm to accommodate a SCS paddle lead measuring 2 mm thick to ensure a final diameter of >10 mm. If canal diameter is <12 mm, aggressive undercutting of the lamina, a second laminotomy, or placement of smaller SCS wire leads should be considered.

Animal Feasibility Study of a Novel Spinal Cord Stimulation Multicolumn Lead (Heron Lead).

BACKGROUND: Currently available spinal cord stimulation paddle leads require a laminectomy, limiting the types of clinicians who can implant and increasing the risk of complications. Recently, WISE S.r.l. designed a prototype multicolumn lead named the Heron® lead that can be implanted percutaneously. The purpose of the study was to examine the efficiency of placing a paddle lead percutaneously. METHODS: Ten sheep were assigned to either the Heron lead group (n = 7) or the control group (n = 3). The sheep were observed for 13 weeks after implantation. Neurological and clinical examinations were conducted prior to surgery and then during the follow-up period. The implantation sites were evaluated through macroscopic observations during the article explantation and the lead migration was evaluated by comparing the article positioning at the surgery, four weeks after the surgery and at the explantation day through fluoroscope images. A qualitative comparison was made between the results collected with the test article and the control article. RESULTS: Observations at the surgical sites indicate that test animals appeared to have less swelling around the surgical wound than control ones in the first 14 days, but no impact on wound healing was noticed. Additionally, no clear difference was observed in pain scores between the two groups, with observations tending to show that the maximum pain was occurring later in the test group with respect to the control group. General clinical observations showed no major difference between the two groups, and determined clinical abnormalities were not directly related to the procedure. Lastly, neurological deficits frequency decreased from the first to last animal operated, regardless of their test or control status. CONCLUSIONS: Our study concluded that the Heron lead is safe to implant, with a safety profile similar to the control article. Additionally, we conclude that the Heron lead is effective in reducing lead migration events.

Differential target multiplexed spinal cord stimulation using a paddle-type lead placed at the appropriate site for neuropathic pain after spinal cord injury in patients with past spinal surgical histories: study protocol for an exploratory clinical trial.

BACKGROUND: Neuropathic pain after spinal cord injury (SCI), both traumatic and non-traumatic, is refractory to various treatments. Spinal cord stimulation (SCS) is one of the neuromodulation therapies for neuropathic pain, although SCS has insufficient efficacy for neuropathic pain after SCI. The reasons are presumed to be inappropriate locations of SCS leads and conventional tonic stimulation itself does not have a sufficient analgesic effect for the pain. In patients with past spinal surgical histories, the cylinder-type leads are likely to be placed on the caudal side of the SCI because of surgical adhesions. Differential target multiplexed (DTM) stimulation is one of the latest new stimulation patterns that is superior to conventional stimulation. METHODS: A single-center, open-label, randomized, two-way crossover trial is planned to investigate the efficacy of SCS using DTM stimulation placing a paddle lead at the appropriate site for neuropathic pain after SCI in patients with spinal surgical histories. The paddle-type lead delivers energy more efficiently than a cylinder-type lead. This study consists of two steps: SCS trial (first step) and SCS system implantation (second step). The primary outcome is rates of achieving pain improvement with more than 33% reduction 3 months after SCS system implantation. The secondary outcomes are to be evaluated as follows: (1) effectiveness of DTM and tonic stimulations during the SCS trial; (2) changes of assessment items from 1 to 24 months; (3) relationships between the result of the SCS trial and the effects 3 months after SCS system implantation; (4) preoperative factors associated with a long-term effect, defined as continuing for more than 12 months; and (5) whether gait function improves from 1 to 24 months. DISCUSSION: A paddle-type lead placed on the rostral side of SCI and using DTM stimulation may provide significant pain relief for patients with intractable neuropathic pain after SCI in patients with past spinal surgical histories. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCT) jRCT 1042220093. Registered on 21 November 2022, and last modified on 6 January 2023. jRCT is approved as a member of the Primary Registry Network of WHO ICTRP.

Paddle Lead Spinal Cord Stimulation in the Morbidly Obese Patient Population: Outcomes and Complications in a Single-Surgeon Cohort.

BACKGROUND: Paddle lead spinal cord stimulation (SCS) is used to treat refractory chronic pain. Morbidly obese patients seek SCS to reduce chronic pain. However, these patients face worse surgical outcomes, and the SCS literature has not evaluated safety and efficacy in this patient population. This study is the largest single-surgeon case series to date on morbidly obese patients with paddle lead SCS implantations. The primary objective is to report postoperative complication rates in morbidly obese patients receiving SCS implants. The secondary objective is to report patient-reported pain scores and Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference and physical function scores in these patients. METHODS: A retrospective chart review was conducted. The patient charts were reviewed from the day of procedure consent to 6 months postop. Demographic information, pain scores, PROMIS scores, neurological complications, infections, and wound complications were documented. RESULTS: Sixty-seven patients were included. The mean preoperative BMI was 44.47 ± 4.02 kg/m2. The mean age was 58.9 ± 11.4 years old. There were no neurological complications. 3/67 (4%) developed culture-positive infections. Nine out of sixty-seven (13%) patients developed superficial wound dehiscence without underlying infection. The mean postop PROMIS physical function score was 31.6 ± 6.2 (n = 16) and the mean post-op PROMIS pain interference score was 64.0 ± 6.4 (n = 16). There was a reduction in pain scores, from 7.9 ± 1.7 preop to 5.7 ± 2.5 postop (n = 22, P = 0.004). CONCLUSIONS: Paddle lead SCS implantation is safe for morbidly obese patients. The only minimal-risk complications present were postoperative infections and wound dehiscence. Surgical care can be modified to further reduce the rates of infection and dehiscence.

Spinal cord stimulation for complex regional pain syndrome type I with spinal myoclonus - a case report and review of literature.

BACKGROUND: Complex regional pain syndrome (CRPS) is a chronic neuropathic painful condition, sometimes associated with spinal myoclonus. For intractable cases spinal cord stimulation is an important modality of treatment but the response of specifically myoclonus to this treatment is not well described. CASE DESCRIPTION: A 40-year old male, had a history of trauma 12 years back since when he had intractable neuropathic pain in his both upper limbs with superimposed severely disabling myoclonic jerks. He had been through multiple treatment failures. We inserted a cervical spinal cord stimulator which led to immediate cessation of myoclonic jerks, with significant improvement in visual analogue score and Oswestry disability index. CONCLUSION: In patients of chronic intractable cervico-brachial pain disorder with superimposed myoclonus, cervical spinal cord stimulation may be effective against the myoclonus as well as the pain.

Is Thoracic Paddle Lead Spinal Cord Stimulator Implantation Safe in an Ambulatory Surgery Center?

OBJECTIVE: Spinal cord stimulation is an effective treatment modality for chronic pain. Although percutaneous leads are commonly placed in the outpatient setting, paddle leads are typically implanted in the inpatient setting. Given the substantial cost savings associated with the ambulatory setting, we aimed to demonstrate the feasibility and safety of thoracic paddle lead implantation in a freestanding ambulatory surgery center (ASC). METHODS: Consecutive patients undergoing thoracic paddle lead implantation at a single freestanding ASC from January 2015 to December 2020 were queried. Demographic, perioperative, and outcome data were collected. Primary outcomes were incidence of intraoperative or immediate postoperative complications and need for inpatient transfer. Secondary outcomes included readmission at 30 and 90 days and reoperation at 30 days, 90 days, and 1 year. RESULTS: A total of 46 patients underwent ambulatory thoracic paddle lead implantation over the study period. Two patients (4.3%) suffered an immediate postoperative complication requiring return to surgery at the ASC-one for an epidural hematoma, and one for a flank hematoma. All but one patient (97.8%) were discharged home on the day of surgery. The overall 30- and 90-day readmission rates were 4.3% and 6.5%, respectively. One patient (2.2%) required reoperation for a mechanical complication. No device-related infections were noted during the follow-up period. CONCLUSIONS: Thoracic laminotomy for paddle lead spinal cord stimulator implantation can be performed in a freestanding ASC with complication rates comparable to the hospital setting. Future comparative studies that assess clinical outcomes and cost are necessary to determine the cost-effectiveness of the ambulatory setting.

Long-Term Changes in Thecal Sac Compression and Decreased Cerebrospinal Fluid Space Following Paddle Lead Spinal Cord Stimulation at T9: A Long-Term Follow-Up via Three-Dimensional Myelographic Computed Tomography.

OBJECTIVES: To investigate the long-term changes in thecal sac compression following T9 paddle lead spinal cord stimulation (SCS) using three-dimensional myelographic computed tomography (CT). MATERIALS AND METHODS: Seventeen patients with five-column paddle lead SCS at T9 underwent three-dimensional myelographic CT scans preoperatively, immediately after surgery, and after an average of 11 months. The cross-sectional areas of thecal sac and spinal cord and the widths of anterior and posterior cerebrospinal fluid (CSF) spaces were repeatedly measured and compared. The contact angle of the lead with long-term pain relief was assessed. RESULTS: The cross-sectional areas of thecal sac and spinal cord decreased significantly after lead placement (30.47 ± 9.21% and 4.71 ± 9.84%, respectively). Even after 11 months, a significant reduction was found with the preoperative values (17.97 ± 12.32% and 2.88 ± 7.09%). The widths of anterior and posterior CSF spaces decreased significantly after surgery (43.53 ± 13.17% and 57.13 ± 13.17%, respectively) and the severe decrease persisted long-term (29.13 ± 21.54% and 50.99 ± 16.07%). The average pain relief was 42.27 ± 17.50% with no correlation between the rate of reduction in cross-sectional areas of thecal sac and the widths of CSF spaces. CONCLUSIONS: Significant early reduction and late partial restoration occurred in the thecal sac and spinal cord and the width of the anterior and posterior CSF spaces in the T9 5-column paddle lead SCS. Thecal sac compromise was expected to some extent after paddle lead implantation, but the degree is significant, and the cross-sectional area of the spinal cord as well as the thecal sac is affected. Fortunately, these anatomical changes did not cause any clinical problems except for intercostal root irritation. The shape and flat contours of the five-column paddle leads clearly affected the results.

Significant epidural electrode migration out of the spinal canal due to prolonged latent infection of the spinal cord stimulation hardware.

Electrode migration is one of the most common complication of Spinal Cord Stimulation (SCS). Usually the lead migrates cranio-caudally or laterally and in the vast majority of cases occurs during the first few months after implantation. One method of preventing lead migration is the use of open-surgical insertion of paddle electrodes. A CASE REPORT: 51-year old woman was admitted for a revision of postoperative wound after implantation of Spinal Cord Stimulator, which was inserted 4 years earlier due to Failed Back Surgery Syndrome (FBSS). Two years after surgery the patient reported severe pain at the site of electrode implantation. After removal of scar tissue pulling on electrode wires the symptoms subsided. In the following months impaired healing of the postoperative wound was observed. For a long time, the patient would not consent to removal of SCS hardware because of good therapeutic effect. When she was finally admitted for surgery, radiological examination demonstrated significant electrode migration out of the vertebral canal. Surgery was performed to remove all of the hardware. CONCLUSIONS: In this case, electrode migration out of the vertebral canal resulted from prolonged infection of SCS hardware. The importance of an infection prevention in neuromodulation procedures should be highlighted. According to our best knowledge, this is the first presented case of paddle type electrode extraspinal migration.

Open Paddle Lead Trial for Spinal Cord Stimulation: An Institutional Experience.

BACKGROUND: Spinal cord stimulation (SCS) is an accepted treatment for certain chronic pain syndromes. It is imperative that patients undergo a stimulation screening trial. For trial stimulation, typically patients undergo a percutaneous lead placement. Due to technical considerations, there exists a subset of patients who are not candidates for a percutaneous trial. OBJECTIVE: We present our experience with open paddle trial for spinal cord stimulation and review the characteristics of this patient population as well as the technique and efficacy of an open paddle lead trial for spinal cord stimulation. STUDY DESIGN: Retrospective review. SETTING: University of Texas Southwestern Medical Center, Department of Neurosurgery. METHODS: We retrospectively identified 25 patients undergoing a paddle lead trial for spinal cord stimulation from September 2014 to September 2019. RESULTS: Twenty-five patients underwent a paddle lead trial for spinal cord stimulation. The average age was 61 with a range of 40 to 82 years; 19 were women and 6 were men. Twenty-two patients (88%) had failed back surgery syndrome (FBSS). Nine patients had attempted percutaneous trials that were unsuccessful, and 14 patients had extensive hardware and/or scar tissue, necessitating an open paddle trial. Twenty-three (92%) patients had a positive trial and went on to permanent implantation. LIMITATIONS: The retrospective nature is a major limitation as well as loss to follow-up on several patients. CONCLUSION: Patients, who have either failed or are deemed suboptimal for percutaneous trialing for spinal cord stimulation, should be considered for open paddle lead trialing. A multidisciplinary approach improves communication and helps to identify that subset of patients who otherwise may be left to pursue conservative measures only.

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.

Compression of Thoracic Spinal Cord with Decreased Cerebrospinal Fluid Space After Implantation of Paddle Lead Spinal Cord Stimulation at T9: A Three-Dimensional Myelographic Computed Tomography Study.

OBJECTIVES: To investigate the extent of spinal cord compression and cerebrospinal fluid (CSF) space after T9 paddle lead spinal cord stimulation (SCS) using three-dimensional myelographic computed tomography scans. METHODS: Preoperative and postoperative three-dimensional myelographic computed tomography scans were performed in 15 patients with paddle lead SCS at T9 for neuropathic back and leg pain. Four axial levels between each row of the electrodes were selected and the cross-sectional areas of thecal sac and spinal cord, the width of anterior and posterior CSF space, and contact angle of the lead within T9 spinal canal were measured with 12-month pain relief assessment. RESULTS: The cross-sectional areas of thecal sac and spinal cord under each contact of paddle leads decreased significantly (23.89 ± 11.48% and 9.45 ± 4.80%; P < 0.05, respectively). The width of posterior CSF space decreased by 38.65 ± 20.97% and that of anterior CSF space showed a greater reduction by 59.09 ± 18.39% (P < 0.05). We achieved a mean pain relief of 45.49 ± 13.73% at 12-month follow-up and found a significant correlation with percentage reduction in the area of the spinal cord. CONCLUSIONS: Significant reduction in the cross-sectional area of spinal cord and anterior CSF space as well as thecal sac and posterior CSF space resulted in deformation of the spinal cord under paddle leads at T9 within 7 postoperative days. Close approximation to the dorsal column and the mass effect of paddle leads may determine the clinical outcome of paddle lead SCS and also raise safety concerns.

Permanent Paddle-lead Trial for Spinal Cord Stimulation.

Objectives A significant number of chronic pain patients rely on spinal cord stimulation (SCS) for treatment of their intractable pain. A screening trial using percutaneous electrodes is an integral step for predicting a successful treatment course with a permanent SCS system. Most of these trials are performed in an outpatient ambulatory surgical center and some in the office setting. However, there are select patients who are considered poor candidates for percutaneous trials. We present the initial report of patients who have received surgical implantation of permanent paddle-leads for SCS trials at our institution and show that this was a safe and effective alternative for our patients who could not undergo percutaneous trials.  Methods We retrospectively reviewed the hospital charts of 12 patients who underwent permanent surgically-implanted paddle-lead trials from 2014 to 2017. Success was considered positive with a 50% reduction in pain rating. If positive, patients were brought back to the operating room to have the implanted leads connected to an internalized pulse generator.    Results All 12 patients met the criteria for a successful trial. Only one patient had his SCS system surgically removed after nine months. None of our patients reported or returned with paddle-lead migrations or infections.  Conclusions We report that surgically-implanted paddle-lead trials were a safe and effective alternative to percutaneous trials in our patients who were deemed poor candidates for percutaneous trials. No complications occurred and all of our patients received a second surgery for internalization of the SCS system. Patients who have previously failed percutaneous trials may be false-negatives to SCS.

A new minimally invasive technique for lead revision of perc-paddle leads.

To report on a less-invasive technique for replacing a broken lead in a spinal cord stimulation (SCS) device that makes use of St. Jude Medical's "Epiducer" device. A 53-year-old woman suffered a loss of stimulation on her internal pulse generator (IPG), which was found to have a broken lead. The broken lead was withdrawn using the Epiducer device with minimal invasiveness and without pain. A new lead was put in place, and successful stimulation using the IPG resumed. Follow-up 3 weeks later showed a well-functioning SCS system. An Epiducer can be used to revise the SCS system in a minimal invasive way without a new puncture. Follow-up study of this technique as well as others for revising an SCS system should be encouraged and used in comparison study.

Intraoperative electrophysiological monitoring for C1-2 spinal cord stimulation.

OBJECTIVE This study is a retrospective case series involving C1-2 spinal cord stimulation in patients with complex regional pain syndrome (CRPS) under general endotracheal anesthesia. Currently, C1-2 paddle lead placement is an accepted practice, which provides effective cervical stimulation to ameliorate upper-extremity and sometimes lower-extremity symptoms experienced by patients with CRPS. However, this technique must be performed under general endotracheal anesthesia rather than in an awake or semiconscious state due to intraoperative safety concerns and patient comfort. The authors aim to provide additional data to support the following novel technique: the use of somatosensory evoked potential (SSEP) diminution data to assist with proper midline placement of C1-2 leads under general anesthesia. METHODS SSEP median nerve (MN) and posterior tibial nerve (PTN) data were collected from 6 patients undergoing placement of C1-2 leads under general anesthesia. Fluoroscopy was used as an initial guide for proper anatomical midline placement. This was followed by the activation of the spinal cord stimulator and simultaneous collection of primarily MN SSEPs as well as PTN SSEPs for physiological midline placement. Unilateral and bilateral reductions in SSEPs assisted with the correct lateralization of the lead to ensure effective postoperative coverage according to the patient's individual preoperative symptoms. RESULTS Six patients were monitored using SSEPs and repeatable, reliable MN and PTN baseline responses were obtained from all. A reduction in amplitude ranging from 5% to 87% was observed, confirming inhibition of dorsal column conduction, and an average pain relief of 63% at short-term and 64% at long-term follow-up was recorded with 6 of 6 and 5 of 6 patients responding, respectively. CONCLUSIONS Intraoperative SSEP collision study testing appears to be a safe technique to monitor placement of C1-2 paddle leads intraoperatively under general anesthesia.

Comparison of Clinical Efficacy and Computed Tomographic Analysis of Lead Position Between Three-Column and Five-Column Paddle Leads Spinal Cord Stimulation for Failed Back Surgery Syndrome.

OBJECTIVE: To investigate the difference in clinical outcome and the position of paddle lead spinal cord stimulation (SCS) between 3-column and 5-column paddle lead SCS in patients with failed back surgery syndrome. METHODS: In 21 patients who underwent paddle lead SCS at T9 (3-column, n = 9; 5-column, n =12) for failed back surgery syndrome, a 12-month follow-up numerical rating scale, percent pain relief, and computed tomography assessment of contact angle and percent reduction of T9 canal area were investigated. RESULTS: There was no difference in paresthesia coverage of the painful area, trial success rate, clinical outcomes, and percent pain relief between the 2 groups (P >0.05). The contact angle in the 5-column group was generally more than that of the 3-column group (P = 0.067). Overall reduction of 35.51% ± 4.76% in the T9 canal was observed and there was no difference between the 2 groups (P >0.05) and no correlation between the contact angle and percent T9 spinal canal reduction (r = -0.247, P > 0.05). CONCLUSIONS: Although clinical efficacy of SCS using three-column and five-column paddle lead was not significant different from each other, significant inclination of paddle lead in posterior epidural space with significant reduction in T9 canal area were observed in both groups. The degree of inclination in the 5-column group was more than that in the 3-column lead group. Close approximation of paddle lead contacts to dorsal spinal cord with reduced dorsal cerebrospinal fluid space and intraoperative neurophysiologic guidance might have contributed to the high rate of trial success and long-term pain control.

Late Spontaneous Migration of a Dorsal Column Stimulator Paddle Lead.

The most frequently encountered complication of dorsal column stimulators is lead migration. The vast majority of these events are seen in the first few weeks to months. Late paddle lead migration is a very uncommon occurrence in this setting. We describe a case of a 51-year-old male with a history of reflex sympathetic dystrophy having undergone dorsal column stimulator insertion at the level of C1-C2. A good clinical benefit was appreciated in the postoperative period once the stimulator was turned on. Approximately six months postoperatively, the patient suddenly lost coverage. Radiographic imaging revealed that the lead had migrated caudally to the C3-C4 level. Subsequent revision surgery took place. This description highlights a common complication, but occurring outside the expected time frame after surgery.