Allergy Considerations in Implanted Neuromodulation Devices

Epidural spread of surgical site infection from spinal cord stimulation trial

We present a case of deep surgical site infection (SSI) at a spinal cord stimulator (SCS) trial implantation site, resulting from an allergic reaction to an unknown agent. A 38-year-old female with complex regional pain syndrome began an SCS trial, noting 100% pain relief for 5 days. Fluid drainage from the surgical site was reported on POD6 and trial leads were removed the following day. The patient was hospitalized with sepsis. Blood cultures revealed Staphylococcus aureus. MRIs showed skin breakdown and cellulitis of the paraspinal musculature extending into the epidural space. The patient was maintained with antibiotics and rigorous wound care for 9 days and the surgical site infection resolved. The patient proceeded to SCS implantation, and reported good pain relief with the implanted device.

A pediatrician's guide to epilepsy surgery

Surgical intervention for epilepsy emerged in the second half of the 20th century as an important option for pediatric patients with medically refractory epilepsy. Both the number of patients undergoing epilepsy surgery and the available surgical procedures for epilepsy have expanded in the last 3 decades, and now range from surgical resection to neuromodulatory device placement1,2 Studies showing that many patients who would be excellent candidates for surgery are still not being offered appropriate interventions have prompted an interest in ensuring that all providers who see patients with epilepsy are aware of the options for epilepsy surgery to facilitate earlier referrals when medications have not been effective3 In this article, we will introduce the pediatrician to the process involved in determining epilepsy surgery candidacy and to surgical outcomes, with the goal of empowering pediatric providers to refer their medically refractory epilepsy patients to a pediatric epilepsy center.

Complications of Spinal Cord Stimulators-A Comprehensive Review Article

PURPOSE OF REVIEW

Spinal cord stimulation has been increasing in influence as an option to regulate pain, especially in the chronic pain patient population. However, even with the numerous changes made to this technology since its inception, it is still prone to various complications such as hardware issues, neurological injury/epidural hematoma, infections, and other biological concerns. The purpose of this article is to thoroughly review and evaluate literature pertaining to the complications associated with percutaneous spinal cord stimulation.

RECENT FINDINGS

Lead migration is generally the most common complication of percutaneous spinal cord stimulation; however, recent utilization of various anchoring techniques has been discussed and experienced clinical success in decreasing the prevalence of lead migration and lead fractures. With newer high-frequency systems gaining traction to improve pain management and decrease complications as compared to traditional systems, rechargeable implantable pulse generators have been the preferred power source. However, recent findings may suggest that these rechargeable implantable pulse generators do not significantly increase battery life as much as was proposed. Intraoperative neuromonitoring has seen success in mitigating neurological injury postoperatively and may see more usage in the future through more testing. Though the occurrence of infection and biological complications, including dural puncture and skin erosion, has been less frequent over time, they should still be treated in accordance with established protocols. While many complications can arise following percutaneous spinal cord stimulator implantation, the procedure is less invasive than open implantation and has seen largely positive patient feedback. Hardware complications, the more common issues that can occur, rarely indicate a serious risk and can generally be remedied through reoperation. However, less common cases such as neurological injury, infections, and biological complications require prompt diagnosis to improve the condition of the patient and prevent significant damage.

Pruritus and urticaria induced by neurostimulation: A case report and review of literature

BACKGROUND

Spinal cord stimulation (SCS) consists of the implantation of neuromodulatory devices in the spinal cord to treat refractory neuropathic pain. Although SCS technology has been proven of immense clinical benefit, complications remain including refractory pain, infection risk, and electrode migration or displacement. Till date, there are minimal reports of allergic side effects following SCS implantation.

CASE DESCRIPTION

In the first case, a 36-year-old male with chronic axial and radicular neuropathic pain in underwent implantation of an open paddle lead and generator. Within 1-3 h of activating the SCS, he developed diffuse raised erythematous hives. Over time, the SCS had immense clinical benefit for his pain reduction; however, he continued to experience recurrent hives and various other allergic reactions including facial flushing and photosensitivity. Four years later, he ultimately opted to retain the device for its clinical pain benefits. In the second case, a 35-year-old female with acute, intractable bilateral occipital neuralgia and a past medical history of Type 1 Chiari Malformation status-post-posterior fossa decompression underwent implantation of an occipital nerve stimulator (ONS). At 1-month follow-up, she began to experience pruritus across the back of her head and along the subcutaneous course of the lead. At 8 months, she continued to experience persistent symptoms, ultimately opting for device removal.

CONCLUSION

Although allergic reactions to implanted neurostimulation systems are rare, and mechanisms not completely understood, existing studies posit multiple theories surrounding the pathophysiology of allergic reactions to these devices, such as delayed hypersensitivity reactions or contact dermatitis. Further research is needed to elucidate the cutaneous and immunologic side effects of SCS and ONS devices.

Posterior cerebral artery stenosis related to implanted intracranial electrodes for temporal lobe epilepsy: A case report

INTRODUCTION

Intracranial electroencephalography is a crucial diagnostic technique for epilepsy surgery, though it is associated with a range of complications, including infection, intracranial hemorrhage, increased intracranial pressure, and cerebral infarction. This case study presents an uncommon occurrence of stenosis of the left posterior cerebral artery (PCA) following intracranial electrode implantation.

CASE PRESENTATION

A woman in her thirties with drug-resistant focal impaired awareness seizures underwent implantation of subdural and depth electrodes on the bilateral temporal lobes to lateralize seizure onset. A left anterior-temporal lobectomy was performed based on the evaluation results. Following the resection of the hippocampus, stenosis of the left PCA, with a pinched appearance, was observed. Postoperatively, extensive cerebral edema in the bilateral temporal lobes and a defect in the left PCA were detected on magnetic resonance (MR) imaging. MR imaging performed the day after surgery showed cerebral infarction in the left medial temporal lobe and left lateral thalamus. A video review indicated that surgical manipulation was not the cause of vascular stenosis. MR angiography one week later confirmed the recanalization of the PCA.

DISCUSSION

We surmised that the subdural electrodes inserted along the middle skull base might have induced the PCA stenosis or spasms. The patient did not experience any significant sequelae, with no episodes of seizures for more than five years after surgery.

CONCLUSION

It is essential to note that subdural grid electrodes placed in the medial temporal lobe can cause vascular stenosis, albeit with an extremely rare occurrence.

Spinal Cord Stimulation in Special Populations: Best Practices from the American Society of Pain and Neuroscience to Improve Safety and Efficacy

Chronic bleeding disorders, allergy to implants, and chronic infections are all complicating factors when considering neuromodulation therapies. The American Society of Pain and Neuroscience (ASPN) determined a need for clinical guidance in these special patient populations that have increased risk of complications, in order to ensure patient safety and optimal outcomes with device implantation. The purpose of this publication was to review the published literature and explore the unique clinical challenges encountered among several special patient populations with relation to spinal cord stimulation. The executive board of the ASPN appointed a diverse group of well-established physicians to develop best practice guidelines regarding spinal cord stimulation implantation in these special populations. The physicians used the United States Preventive Services Task Force (USPSTF) structured guidelines for grading and level of certainty to make evidence-based recommendations about clinical practice. Where sufficient evidence was lacking to justify a USPSTF ranking, the physicians queried experts in neuromodulation and achieved consensus. These best practices and interventional guideline found the evidence for the use of neuromodulation in specialized patient populations to be relatively modest.