A Survey on the Choice of Spinal Cord Stimulation Parameters and Implantable Pulse Generators and on Reasons for Explantation.

Objective: Spinal Cord Stimulation (SCS) is a vital treatment for chronic intractable pain. In the last few years, the field has undergone dramatic changes in new waveform and frequency introduction as well as device miniaturization. It is important to understand contemporary practice patterns regarding these parameters. Methods: We surveyed the active membership of Spine Intervention Society (SIS), and American Society of Regional Anesthesia (ASRA) on their practices regarding various aspects of Spinal Cord Stimulation therapy. Here we report on SCS waveform usage, battery types, and causes of explant in this cohort of providers. Results: There was similar degree of usage of tonic, burst, and 10 kHz usage at 71.5%, 74.1% and 61.7% respectively. Dorsal root ganglion stimulation was used by 32.6% and other modes of stimulation by 13.5%. Rechargeable systems were often or always used by 67.2% whereas 10% never used a rechargeable system. Most common cause of explant was loss of effectiveness, reported by 53.7%. Conclusion: There has been significant adoption of new waveforms in daily practice of spinal cord stimulation therapy and there is robust mixed usage of new waveforms and frequencies. Rechargeable systems are the most commonly used but primary cell is also used in significant numbers. Loss of efficacy remains the most common cause of explant for the majority of practitioners. This survey establishes practice patterns of SCS usage regarding these important variables against which future changes can be gauged.

Dural Puncture During Spinal Cord Stimulator Lead Insertion: Analysis of Practice Patterns.

Background: Spinal cord stimulation (SCS) is an important modality for intractable pain not amenable to less conservative measures. During percutaneous SCS lead insertion, a critical step is safe access to the epidural space, which can be complicated by a dural puncture. Objectives: In this review, we present and analyze the practices patterns in the event of a dural puncture during a SCS trial or implantation. Methods: We conducted a survey of the practice patterns regarding spinal cord stimulation therapy. The survey was administered to members of the Spine Intervention Society and American Society of Regional Anesthesia specifically inquiring decision making in case of inadvertent dural puncture during spinal cord stimulator lead insertion. Results: A maximum of 193 responded to a question regarding dural punctures while performing a SCS trial and 180 responded to a question regarding dural punctures while performing a SCS implantation. If performing a SCS trial and a dural puncture occurs, a majority of physicians chose to continue the procedure at a different level (56.99%), followed by abandoning the procedure (27.98%), continuing at the same level (10.36%), or choosing another option (4.66%). Similarly, if performing a permanent implantation and a dural puncture occurs, most physicians chose to continue the procedure at a different level (61.67%), followed by abandoning the procedure (21.67%), continuing at the same level (10.56%), or choosing another option (6.11%). Conclusions: Whereas the goals of the procedure would support abandoning the trial but continuing with the permanent in case of inadvertent dural puncture, we found that decision choices were minimally influenced by whether the dural puncture occurred during the trial or the permanent implant. The majority chose to continue with the procedure at a different level while close to a quarter chose to abandon the procedure. This article sets a time stamp in practice patterns from March 20, 2020 to June 26, 2020. These results are based on contemporary SCS practices as demonstrated by this cohort, rendering the options of abandoning or continuing after dural puncture as reasonable methods. Though more data is needed to provide a consensus, providers can now see how others manage dural punctures during SCS procedures.

Contralateral and Lateral Views: Analysis of the Technical Aspects of Spinal Cord Stimulator Lead Insertion.

Background: Spinal cord stimulation (SCS) is an established treatment modality for neuropathic pain. The critical part of this technique is safe access to the epidural space for lead placement. There have been innovations in radiological views, improving access to the epidural space. Objectives: This study analyzes the adoption of these technical advantages in daily practice. Methods: We conducted a survey of members in the Spine Intervention Society and American Society of Regional Anesthesia in regard to the practice patterns in SCS therapy. Here we present our findings regarding the use of contralateral oblique (CLO) and lateral views as well direct upper thoracic or cervicothoracic access for SCS lead insertion. Results: A total of 195 unique responses were received between March 20, 2020 and June 26, 2020. Forty-five percent of respondents "always used" the lateral view technique while 15% "always used" CLO view for SCS lead insertion. Overall, sixty-five percent of respondents used the CLO view with varying frequency. Cervical and upper thoracic approach for cervical SCS lead placement is always or often used by 66.8% of the respondents. Conclusions: A depth view (CLO or lateral) is always used by only 45 - 60% of the respondents and CLO view has been rapidly adopted in clinical practice for SCS lead insertion. Direct cervicothoracic and upper thoracic is the preferred approach for cervical lead placement by the majority.

Percutaneous Spinal Cord Stimulation Lead Placement Under Deep Sedation and General Anesthesia.

INTRODUCTION: Spinal cord stimulation (SCS) is a commonly utilized therapy for the treatment of neuropathic pain conditions. The Neurostimulation Appropriateness Consensus Committee (NACC) has recommended that the placement of percutaneous SCS leads be performed in an awake patient capable of providing feedback. It is not currently known how commonly this recommendation is adhered to by physicians in clinical practice. This article presents the findings of a survey designed to answer this important question. METHODS: We conducted a survey of the active membership of the American Society of Regional Anesthesia and Pain Medicine (ASRA) and the Spine Intervention Society (SIS) regarding practice patterns with SCS therapy. We analyzed the percent of respondents who indicated that they use deep sedation and general anesthesia during SCS placement as well as any reported complications. RESULTS: Many practitioners frequently utilize deep sedation as well as general anesthesia when performing SCS implants. Our findings demonstrate that 77% of physicians reported that they utilize deep sedation for permanent SCS implants at times, and 45% of physicians reported the use of general anesthesia for 10 kHz implants. Additionally, 94% of physicians reported that they have never had a complication related to the use of general anesthesia for a spinal cord stimulator placement. CONCLUSIONS: This survey provides initial data on SCS practices among a large cohort of clinicians who utilize SCS. SCS lead placement under deep sedation and general anesthesia appears to be common practice for many physicians who perform implants. This survey should stimulate further research on this topic, given that the current safety guidelines and the rate of physicians reporting the use of deep sedation and general anesthesia for spinal cord stimulator placement remain at odds.

Improved Pain Control with Combination Spinal Cord Stimulator Therapy Utilizing Sub-perception and Traditional Paresthesia Based Waveforms: A Pilot Study.

BACKGROUND: Chronic back and neck pain affects 20% of Americans. Spinal cord stimulation (SCS) is an effective therapy for otherwise refractory chronic pain. Traditional SCS relies on low-frequency stimulus in the 40 - 60 Hz range causing robust paresthesia in regions overlapping with painful dermatomes. OBJECTIVES: This study aims to determine the effect of superimposing sub-perception stimulation in patients who previously had good long-term relief with paresthesia. METHODS: This is a prospective observational trial examining patients who had previously been implanted with paresthesia based SCS for failed back surgery syndrome (FBSS) or complex regional pain syndrome (CRPS). These patients presented for implantable pulse generator (IPG) replacement based on battery depletion with an IPG capable of combined sub-perception and paresthesia based SCS therapy. Patients were assessed immediately following the exchange and four weeks later using a telephone survey. Their pain was assessed on each follow up using a Numerical Rating scale (NRS); the primary outcome was the change in NRS after four weeks from the exchange day. Secondary outcomes included paresthesia changes, which included the subjective quality of sensation generated, the overall subjective coverage of the painful region, subjective variation of coverage with positional changes, and global perception of the percentage improvement in pain. RESULTS: Based on our clinic registry, 30 patients were eligible for IPG exchange, 16 were consented for follow up and underwent an exchange, and 15 were available for follow up four weeks following. The average NRS decreased from 7.47 with traditional SCS to 4.5 with combination therapy. 80% of patients reported an improvement in the quality of paresthesia over traditional SCS therapy, and in most patients, this translated to significantly improved pain control. CONCLUSIONS: Our findings suggest improved pain relief in patients who had previously had good results with paresthesia based therapy and subsequently underwent IPG exchange to a device capable of delivering combined sub-perception stimulation. The mechanism of action is unclear though there may be an additive and/or synergistic effect of the two waveforms delivered. Larger studies with long-term follow-up are needed to elucidate the durability of pain relief and the precise mechanism by which combined subperception and paresthesia based SCS may improve overall patient outcomes.

Utilization of Erector Spinae Plane Block in the Chronic Pain Clinic for Two Patients With Post-Thoracotomy Pain.

The erector spinae plane (ESP) block is a regional block that has become more commonly utilized in the setting of acute pain and post-operative analgesia. This block has been successfully utilized for pain management after a variety of surgical procedures for immediate post-operative pain management. This block is now gaining more utilization in the chronic pain setting for neuropathic pain conditions. We describe the use of this block at our pain clinic for the treatment of two patients with refractory neuropathic pain after thoracotomy as well as video-assisted thoracic surgery (VATS). Our cases further demonstrate the utility of this block for long-term pain control of neuropathic pain conditions, especially post-thoracotomy pain.

Role of interventional pain management in patients with chronic pelvic pain.

Patients with chronic pelvic pain are often referred to a variety of specialists in gynecology, urology, and gastroenterology with the hope of finding a diagnosis and treatment. We describe a 51-year-old woman with long-standing chronic pelvic pain secondary to endometriosis who was successfully treated with superior hypogastric plexus blocks. Physicians should consider referring patients to interventional pain specialists for assistance with pain control after thorough diagnostic evaluation.

Cannabis Use in Hospitalized Patients with Chronic Pain.

INTRODUCTION: To date, no study has reported the prevalence of cannabis use in chronic pain patients. The aim of this study is to investigate the trends in cannabis use among chronic pain in-patients from 2011 to 2015 in the USA. METHODS: Patients were identified from the National Inpatient Sample (NIS) database using the International Classification of Diseases, Ninth and Tenth Revision, diagnosis codes for chronic pain and cannabis use. Annual estimates and trends were determined for cannabis use, patient characteristics, cannabis use among subgroups of chronic pain conditions, cost, length of stay, and associated discharge diagnosis. RESULTS: Between 2011 to 2015, a total of 247,949 chronic pain patients were cannabis users, increasing from 33,189 to 72,115 (P < 0.001). There were upward trends of cannabis use in females (38.7-40.7%; P = 0.03), Medicare insured patients (32.7-40.4%; P < 0.01), patients with lowest annual household income (36.1-40.9%; P = 0.02), patients aged 45-64 years (45.9-49.2%; P < 0.001), and patients with tobacco use disorder (63.8-72.4%; P < 0.0001). Concurrently, cannabis use decreased among patients with opioid use disorder (23.8-19.9%; P < 0.001). Cannabis use increased from 2011 to 2015 in patients with chronic regional pain syndrome, trauma, spondylosis, and failed back surgery syndrome. Adjusted total hospitalization cost increased from $31,271 ($1333) in 2011 to $38,684 ($946) in 2015 (P < 0.001). CONCLUSIONS: Cannabis use increased substantially from 2011 to 2015, while the rates of cannabis use in opioid users down-trended simultaneously. Disparities in cannabis use among subgroups should be explored further.

Spinal cord stimulation for the treatment of chronic pelvic pain after Tarlov cyst surgery in a 66-year-old woman: A case report.

Tarlov cysts are extradural meningeal cysts with collections of cerebrospinal fluid within the nerve sheath. These cysts are uncommon but tend to present more often in women. Symptomatic Tarlov cysts can lead to a variety of neurologic symptoms and painful conditions, including chronic pelvic pain. There is no consensus regarding the best treatment for symptomatic cysts. Surgical management has high rates of complication, including chronic pain, but better long-term results for symptom and cyst resolution. We describe a patient who developed worsening pelvic pain and lumbar radiculopathy after surgical management of her Tarlov cysts. Medication failed to relieve the pain, as did a variety of other procedures, before the patient ultimately received significant pain relief from high-frequency spinal cord stimulation. This case may provide guidance for physicians when managing patients suffering from symptomatic Tarlov cysts, or worsening pain symptoms after surgical management of these cysts.

Post Dural Puncture Headache, Managed with Epidural Blood Patch, Is Associated with Subsequent Chronic Low Back Pain in Patients: a Pilot Study.

PURPOSE OF REVIEW: Post dural puncture headache (PDPH) is a relatively common complication which may occur in the setting of inadvertent dural puncture (DP) during labor epidural analgesia and during intentional DP during spinal anesthetic placement or diagnostic lumbar puncture. Few publications have established the long-term safety of an epidural blood patch (EBP) for the treatment of a PDPH. RECENT FINDINGS: The aim of this pilot study was to examine the association of chronic low back pain (LBP) in patients who experienced a PDPH following labor analgesia and were treated with an EBP. A total of 146 patients were contacted and completed a survey questionnaire via telephone. The EBP group was found to be more likely to have chronic LBP (percentage difference 20% [95% CI 6-33%], RR 2.6 [95% CI 1.3-5.2]) and also LBP < 6 (percentage difference 24% [95% CI 9- 37%], RR 2.3 [95% CI 1.3-4.1]). There were no significant differences in the severity and descriptive qualities of pain between the EBP and non-EBP groups. Our findings suggest that PDPH treated with an EBP is associated with an increased prevalence of subsequent low back pain in parturients. The findings of this pilot study should spur further prospective research into identifying potential associations between DP, EBP, and chronic low back pain.

Implementing and Evaluating a Multihospital Standardized Opioid Curriculum for Surgical Providers.

OBJECTIVE: (1) To identify gaps in providers knowledge on opioid medication and dosing, patient-specific characteristics that require alterations in dosing, and patient monitoring and treatment adjustments. (2) To evaluate an educational intervention aimed at minimizing these deficits. DESIGN: Observational prospective study. Providers took an anonymous paired pre-and posteducation knowledge assessment before and after participating in a 75-minute educational session. Results before and after the educational session were compared. SETTING: Surgical providers included nurse practitioners, physician assistants, preinterns, and general surgery residents across 4 quaternary care hospitals in Boston. Participants There were 194 participants and 174 completed both pre- and posteducation knowledge assessments. RESULTS: Average scores on the educational assessment increased from 59% before the course to 68% after the session. Posteducation, providers reported increased comfort in prescribing and 95% stated that the curriculum would impact their practice. CONCLUSIONS: Surgical providers at multiple hospitals have significant gaps in knowledge for optimal prescribing and management of opioid prescriptions. A 75-minute opioid education session increased prescriber knowledge as well as comfort in prescribing. This multicenter study demonstrates how an educational initiative can be implemented broadly and result in decreased knowledge gaps.

Epidural Blood Patch does not Contribute to the Development of Chronic Low Back Pain in Patients who Undergo Lumbar Punctures: A Pilot Study.

Purpose of Review: Post dural puncture headache (PDPH) is a known and relatively common complication which may occur in the setting of patients undergoing lumbar punctures (LP) for diagnostic or therapeutic purposes, and is commonly treated with an epidural blood patch (EBP). There have been few publications regarding the long-term safety of EBP for the treatment of PDPH. Recent Findings: The aim of this pilot study was to examine any association of chronic low back pain (LBP) in patients who experienced a PDPH following a LP, and were treated with an EBP. A total of 49 patients were contacted and completed a survey questionnaire via telephone. There was no increased risk of chronic LBP in the dural puncture group receiving EBP (percentage difference 1% [95% CI -25% - 26%], RR: 0.98 [95% CI 0.49 - 1.99]) compared to the dural puncture group not receiving EBP. There were no significant differences in the severity and descriptive qualities of pain between the EBP and non-EBP groups. Both groups had higher prevalence of back pain compared to baseline. Summary: Our findings suggest that dural puncture patients undergoing EBP do not experience low back pain with increased frequency compared to dural puncture patients not undergoing EBP. Higher prevalence of LBP compared to baseline and compared to general population was seen in both groups. However, this pilot study is limited by a small sample size and no definitive conclusion can be drawn from this observation. The findings of this study should spur further prospective research into identifying potential associations between LP, EBP and chronic low back pain.

Long-Term Outcomes of Post Dural Puncture Headache Treated With Epidural Blood Patch: A Pilot Study.

Background: Post dural puncture headache (PDPH) is a known complication which may occur in the setting of patients undergoing lumbar punctures (LP) for diagnostic or therapeutic purposes. The gold standard for treating a PDPH is an epidural blood patch (EBP). There have been few publications evaluating the long-term outcomes of PDPH treated with EBP. The aim of this pilot study was to examine the incidence of chronic headaches in dural puncture patients who received EBP versus those who did not. Methods: A retrospective case control study was performed at a single large center institution. Forty-nine patients who had intentional dural puncture were identified on chart review and completed a survey questionnaire via phone interview: twenty-six of these patients required a subsequent EBP, while twenty-three did not. The primary outcomes were the development and prevalence of chronic headaches after the procedures. There was no statistically significant difference in the prevalence of current headaches between the EBP group and Non-EBP group (54% vs. 52% p = 0.91). There were no significant differences in the rates of severity and descriptive qualities of headache between the EBP and non-EBP groups. There was higher incidence of tinnitus in the PDPH patients. Summary: This pilot study demonstrates that patients who received an EBP for treatment of a PDPH following LP are no more likely to experience chronic headaches compared to patients who do not receive an EBP. However, both the EBP group and Non-EBP group had high incidence of chronic headaches which may be related to dural puncture or a baseline trait of this cohort given the recall bias. There is a suggestion that tinnitus could be a long-term residual symptom of PDPH treated with EBP.