A Rare Case of Anchor Fracture Manifesting With New-Onset Neuropathic Pain After Spinal Cord Stimulator Implantation

Treatment of pain in length-dependent peripheral neuropathy with the use of spinal cord stimulation: a systematic review

BACKGROUND

Chronic intractable pain from peripheral neuropathy is a debilitating condition that might not respond to conventional medical management and pharmacotherapy. The primary objective of this systematic review was to assess change (or reduction) in pain intensity in patients with length-dependent peripheral neuropathy after spinal cord stimulation (SCS) therapy.

METHODS

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The primary outcome was change (or reduction) in pain intensity after 12 months of SCS therapy compared with baseline in participants with length-dependent peripheral neuropathy. Secondary outcomes included change in pain intensity after 6 months and change in opioid consumption after 12 months. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidelines were used to appraise the quality of evidence.

RESULTS

Nineteen studies consisting of 376 participants who underwent SCS implantation met the inclusion criteria. Qualitative synthesis revealed that all eligible studies reported a significant improvement in pain intensity after 12 months of SCS therapy as compared with baseline. Mean differences with 95% confidence intervals were calculated for 4 studies, all of which achieved the minimal clinically important difference for change in pain intensity at 12 months. The GRADE quality of evidence for this outcome was appraised as very low quality.

CONCLUSION

This systematic review highlights that SCS could lead to significant improvement in pain intensity for length-dependent peripheral neuropathy, although future well-powered randomized controlled trials are warranted to increase the certainty of evidence in this finding.

STUDY REGISTRATION

PROSPERO (https://www.crd.york.ac.uk/PROSPERO/) ID: CRD42022377572.

Incidence of Neuraxial and Non-Neuraxial Hematoma Complications From Spinal Cord Stimulator Surgery: Systematic Review and Proportional Meta-Analysis

OBJECTIVE

The goal of this meta-analysis was to estimate the incidence of total hematomas, neuraxial hematomas, and non-neuraxial hematomas in patients who underwent temporary spinal cord stimulator (SCS) lead trial placement and permanent implantation of SCS leads and internal pulse generator (IPG).

MATERIALS AND METHODS

A comprehensive search was conducted of databases of any publications before October 21, 2021. Eligible study designs included randomized control trials and prospective or retrospective observational studies with more than ten patients. The primary outcome variables were the incidences of total hematomas, neuraxial hematomas, and non-neuraxial hematomas in patients with SCS. These dichotomous categorical outcomes were abstracted from studies after Freeman-Tukey arcsine square root transformation using random-effects meta-analysis (DerSimonian and Laird method). Pooled incidence rates and 95% CIs were calculated for each outcome variable.

RESULTS

A total of 40 studies met the inclusion criteria. Included in the neuraxial and non-neuraxial hematoma analyses were 4751 patients and 3862 patients, respectively. The pooled incidence of any hematoma in patients with SCS was 0.81% (95% CI, 0.45%-1.27%). The pooled incidence of neuraxial hematoma in patients with SCS was 0.32% (95% CI, 0.18%-0.50%). This included primarily epidural hematomas (11/4751) but also comprised an intracranial hemorrhage in a patient on enoxaparin bridge therapy from warfarin and one patient not on anticoagulation with an intracranial subdural hematoma that resulted in death. The pooled incidence of non-neuraxial hematomas in patients with SCS was 0.59% (95% CI, 0.29%-1.00%).

CONCLUSION

The overall incidence of hematomas in patients with temporary SCS trial lead placement and permanent SCS/IPG implantations is less than 1%. Furthermore, the incidence of neuraxial hematomas is less than 0.5%, which is of particular interest given the potential devastating consequences of this complication. The results of this study can be used to inform patients and implanting physicians on hematoma complications from SCS and highlight that the benefits of SCS outweigh the hematoma risks if anticoagulation is appropriately managed perioperatively.

Incidence of Lead Migration With Loss of Efficacy or Paresthesia Coverage After Spinal Cord Stimulator Implantation: Systematic Review and Proportional Meta-Analysis of Prospective Studies and Randomized Clinical Trials

OBJECTIVE

The objective of this meta-analysis was to approximate the incidence of overall lead migration, clinically significant lead migration, and asymptomatic lead migration in patients who have undergone spinal cord stimulator implantation.

MATERIALS AND METHODS

A comprehensive literature search was performed for studies published before May 31, 2022. Only randomized controlled trials and prospective observational studies with more than ten patients were included. Two reviewers analyzed the articles from the literature search for final inclusion, after which, study characteristics and outcome data were extracted. The primary dichotomous categorical outcome variables were the incidence of overall lead migration, clinically significant lead migration (defined as lead migration resulting in loss of efficacy), and asymptomatic lead migration (defined as lead migration discovered incidentally on follow-up imaging) in patients with spinal cord stimulator implant. Freeman-Tukey arcsine square root transformation for meta-analysis of proportions using random effects (DerSimonian and Laird method) was used to calculate incidence rates for the outcome variables. Pooled incidence rates and 95% CIs were calculated for the outcome variables.

RESULTS

Fifty-three studies met the inclusion criteria, with a total of 2932 patients having received spinal cord stimulator implants. The pooled incidence of overall lead migration was 9.97% (95% CI of 7.62%-12.59%). Only 24 of the included studies commented on the clinical significance of reported lead migrations, of which every lead migration was clinically significant. In these 24 studies, 96% of the reported lead migrations required a revision procedure or explant. Unfortunately, no studies that reported lead migration commented on asymptomatic lead migrations; therefore, the incidence of asymptomatic lead migrations could not be defined.

CONCLUSIONS

This meta-analysis found that the rate of lead migration in patients who have received spinal cord stimulator implants is approximately one in ten patients. This likely closely approximates the incidence of clinically significant lead migration owing to the included studies not routinely performing follow-up imaging. Therefore, lead migrations were primarily discovered owing to loss of efficacy, and no included studies clearly reported asymptomatic lead migration. The results of this meta-analysis can be used to inform patients more accurately on the risks and benefits of spinal cord stimulator implantation.

Evidence-Based Treatment of Painful Diabetic Neuropathy: a Systematic Review

PURPOSE OF REVIEW

Painful diabetic neuropathy (PDN) manifests with pain typically in the distal lower extremities and can be challenging to treat. The authors appraised the literature for evidence on conservative, pharmacological, and neuromodulation treatment options for PDN.

RECENT FINDINGS

Intensive glycemic control with insulin in patients with type 1 diabetes may be associated with lower odds of distal symmetric polyneuropathy compared to patients who receive conventional insulin therapy. First-line pharmacologic therapy for PDN includes gabapentinoids (pregabalin and gabapentin) and duloxetine. Additional pharmacologic modalities that are approved by the Food and Drug Administration (FDA) but are considered second-line agents include tapentadol and 8% capsaicin patch, although studies have revealed modest treatment effects from these modalities. There is level I evidence on the use of dorsal column spinal cord stimulation (SCS) for treatment of PDN, delivering either a 10-kHz waveform or tonic waveform. In summary, this review provides an overview of treatment options for PDN. Furthermore, it provides updates on the level of evidence for SCS therapy in cases of PDN refractory to conventional medical therapy.

Neuromodulation Interventions for the Treatment of Painful Diabetic Neuropathy: a Systematic Review

PURPOSE OF REVIEW

Painful diabetic neuropathy (PDN) is a prevalent and debilitating condition, characterized by severe burning, tingling, and lancinating pain usually located in the distal lower extremities. In addition to manifesting with severe pain, PDN may also be associated with poor quality of life and sleep, mood disorders, burns, falls, and social withdrawal. The authors appraised the current body of literature for evidence on neuromodulation interventions for PDN.

RECENT FINDINGS

In patients with refractory PDN unresponsive to conventional medical management (glucose optimization and oral analgesic medications), there is level I evidence supporting the use of 10-kHz and tonic dorsal column spinal cord stimulation (SCS). Included studies reported significant associations between 10-kHz and tonic dorsal column SCS and superior analgesic outcomes, physical functioning, and patient satisfaction. Current level of evidence remains limited for other modalities of neuromodulation for PDN including burst SCS (level II-3), dorsal root ganglion SCS (level III), and peripheral nerve stimulation (level II-3). Some studies reported improvements in neurological physical examination, sensory testing, and/or reflex testing in patients undergoing 10-kHz SCS for treatment of PDN. In summary, the purpose of this review is to equip provider with important updates on the use of neuromodulation interventions for the treatment of PDN that is refractory to conventional medical therapy, with current level I evidence supporting use of 10-kHz and tonic SCS for PDN.

Adverse Events Associated With 10-kHz Dorsal Column Spinal Cord Stimulation: A 5-Year Analysis of the Manufacturer and User Facility Device Experience (MAUDE) Database

BACKGROUND

High-frequency (10-kHz) spinal cord stimulation (SCS) continues to be an emerging therapy in chronic pain management. The same complications that plagued earlier SCS systems may affect newer stimulation technologies, although there is limited data on the type of complications and surgical management of these complications.

OBJECTIVE

The aim of this study was to systematically examine real-world complications associated with 10-kHz SCS reported on the Manufacturer and User Facility Device Experience (MAUDE) database.

MATERIALS AND METHODS

The MAUDE database was queried for entries reported between January 1, 2016 and December 31, 2020. Entries were classified into procedural complications, device-related complications, patient complaints, surgically managed complications, serious adverse events, and/or other complications. Primary outcomes included type and frequency of complications, and surgical management of complications.

RESULTS

A total of 1651 entries were analyzed. Most entries were categorized as procedural complications (72.6%), followed by serious adverse events (10.5%), device-related complications (10.5%), and patient complaints (9.9%). Most complications were managed surgically with explant (50.9%) rather than revision (5.0%) or incision/drainage (6.6%). Of procedural complications, the most common entries included non-neuraxial infection (52.9%), new neurological symptoms (14.7%), and dural puncture (9.5%). Of device-related complications, the most common entries included lead damage (41.6%), erosion (18.5%), and difficult insertion (11.5%).

CONCLUSION

This retrospective 5-year analysis of complications from10-kHz SCS provides a real-world assessment of safety data unique for this stimulation modality. This analysis may help inform future clinical decisions, lead to device enhancement and optimization, and improve mitigation of risks to provide safe and efficacious use of 10-kHz SCS.