Characterizing Complications of Intracranial Responsive Neurostimulation Devices for Epilepsy Through a Retrospective Analysis of the Federal MAUDE Database.

OBJECTIVES: Responsive neurostimulation is an innovative modality in the treatment of medication-refractory epilepsy for patients who are not suitable candidates for surgical intervention. While being a potentially life-changing treatment option for many individuals with epilepsy, little is known about the system's complications aside from its performance in initial clinical trials. Therefore, the goal of this study was to characterize all reported complications of the RNS system made to the Food & Drug Administration since its approval. MATERIALS AND METHODS: The Manufacturer and User Facility Device Experience (MAUDE) database was queried for entries reported under "implanted brain stimulator for epilepsy" through the dates of November 1, 2013, to March 1, 2020. After correction of duplicate entries, each was sorted into complication types based on the entries' narrative descriptions. RESULTS: The searched yielded 241 unique complication events. The most common complications were attributed to infections (40%) and lead breaks (12%). Other reported complications included poor wound healing (10%) and intrinsic device failure (7%). Focal neurological deficits were found in 2%. Over half (67%) of the reported complications required return to the operating room for revision or explant. The remainder of the adverse events were self-resolved or treated with either medication or software adjustment. CONCLUSIONS: Future research endeavors should attempt to optimize the implantable device for preventing infections. The data of complications provided by this review will also aid physicians in providing the most accurate informed consent for patients when deciding to undergo implantation with the responsive neurostimulation system.

Neuromodulation of the lingual nerve: a novel technique.

Acute injury of the trigeminal nerve or its branches can result in posttraumatic trigeminal neuropathy (PTTN). Affected patients suffer from chronic debilitating symptoms long after they have recovered from the inciting trauma. Symptoms vary but usually consist of paresthesia, allodynia, dysesthesia, hyperalgesia, or a combination of these symptoms. PTTN of the trigeminal nerve can result from a variety of traumas, including iatrogenic injury from various dental and maxillofacial procedures. Treatments include medications, pulsed radiofrequency modulation, and microsurgical repair. Although trigeminal nerve stimulation has been reported for trigeminal neuropathy, V3 implantation is often avoided because of an elevated migration risk secondary to mandibular motion, and lingual nerve implantation has not been documented. Here, the authors report on a patient who suffered from refractory PTTN despite multiple alternative treatments. He elected to undergo novel placement of a lingual nerve stimulator for neuromodulation therapy. To the best of the authors' knowledge, this is the first documented case of lingual nerve stimulator implantation for lingual neuropathy, a technique for potentially reducing the risk of electrode migration.

Risk Factors Associated with Lead Migration Requiring Revision in Dorsal Root Ganglion Stimulation.

BACKGROUND: Neuromodulation is an evolving therapy for chronic pain. Aiming to meet the limitations of traditional spinal cord stimulation, dorsal root ganglion (DRG) stimulation targets pain in a dermatomal distribution at the site of pain transmission. Despite these advantages, lead migration is a significant complication that hinders the long-term efficacy of DRG stimulation. This study aims to identify risk factors for lead migration requiring revision in DRG stimulation. METHODS: We performed a retrospective review of all subjects who had DRG stimulators implanted at T10-S2 by a single physician over a 2-year period. Their history was reviewed for the following: age, sex, diagnosis, lead placement, reported symptom relief, complications, and postoperative activity. RESULTS: In total, 19 cases of DRG stimulator implantation were identified. All patients reported pain relief, with 84.2% (16/19) describing >50% relief. In total, 31.6% of patients (6/19) developed lead migration and 15.8% of total implanted leads (9/57) migrated. Of the migrated leads, 4% (4/9) occurred at S1 and 33.3% (3/9) occurred at L4. The underlying etiology of lead migration was clear and preventable in 66.7% of patients (4/6). All patients who developed lead migration were women. CONCLUSIONS: Premature activity, hardware manipulation, and female sex appear to be associated with an increased risk for lead migration. Leads on the S1 and L4 locations may be more likely to migrate. Large trials are necessary to gain a more conclusive understanding of these risk factors for lead migration.

The 50 Most Cited Articles in Invasive Neuromodulation.

OBJECTIVE: Bibliometric analysis is a commonly used analytic tool for objective determination of the most influential and peer-recognized articles within a given field. This study is the first bibliometric analysis of the literature in the field of invasive neuromodulation, excluding deep brain stimulation. The objectives of this study are to identify the 50 most cited articles in invasive neuromodulation, provide an overview of the literature to assist in clinical education, and evaluate the effect of impact factor on manuscript recognition. METHODS: Bibliometric analysis was performed using the Science Citation Index from the Institute for Scientific Information, accessed through the Web of Science. Search terms relevant to the field of invasive neuromodulation were used to identify the 50 most cited journal articles between 1900 and 2016. RESULTS: The median number of citations was 236 (range, 173-578). The most common topics among the articles were vagus nerve stimulation (n = 24), spinal cord stimulation (n = 9), and motor cortex stimulation (n = 6). Median journal impact factor was 5.57. Most of these articles (n = 19) contained level I, II, or III evidence. CONCLUSIONS: This analysis provides a brief look into the most cited articles within the field, many of which evaluated innovated procedures and therapies that helped to drive surgical neuromodulation forward. These landmark articles contain vital clinical and educational information that remains relevant to clinicians and students within the field and provide insight into areas of expanding research. Journal impact factor may play a significant role in determining the literary relevance and general awareness of invasive neuromodulation studies.

Potential Uses of Isolated Toxin Peptides in Neuropathic Pain Relief: A Literature Review.

Neuropathic pain is a subset of chronic pain that is caused by neurons that are damaged or firing aberrantly in the peripheral or central nervous systems. The treatment guidelines for neuropathic pain include antidepressants, calcium channel α2 delta ligands, topical therapy, and opioids as a second-line option. Pharmacotherapy has not been effective in the treatment of neuropathic pain except in the treatment of trigeminal neuralgia with carbamazepine. The inability to properly treat neuropathic pain causes frustration in both the patients and their treating physicians. Venoms, which are classically believed to be causes of pain and death, have peptide components that have been implicated in pain relief. Although some venoms are efficacious and have shown benefits in patients, their side-effect profile precludes their more widespread use. This review identifies and explores the use of venoms in neuropathic pain relief. This treatment can open doors to potential therapeutic targets. We believe that further research into the mechanisms of action of these receptors as well as their functions in nature will provide alternative therapies as well as a window into how they affect neuropathic pain.

Investigating Complications Associated With Occipital Nerve Stimulation: A MAUDE Study.

OBJECTIVES: The objectives of this study are to utilize the MAUDE data base to enhance our understanding of the complication profile for Occipital Nerve Stimulation, a therapy for which the current level of evidence is limited. Additionally, it is our objective to describe a systematic approach to processing the MAUDE data, which addresses its flaws and enhances its utility. METHODS: From the FDA website, we accessed adverse events reports from the MAUDE data base for devices used in Occipital Nerve Stimulation between June 30, 2007 and June 30, 2017. All reports were sorted into an overall classification for types of adverse events, types of patient complaints, and types of specific device-related complications. We then evaluated for the total number of adverse event reports that contained each of the patient complains and device-related complications. RESULTS: A total of 1233 adverse event records were obtained. Eight hundred twenty-two records were classified as surgically manageable post-operative complications, 121 as device malfunction, 29 as patient compliance issues, and 27 as intra-operative complications. Two hundred thirty-seven records were not classified. A total of 683 records contained patient complaints including 467 complaints of ineffective stimulation, 122 complaints of inappropriate or over-stimulation, 50 complaints of device-shock, and 44 complaints of IPG site pain. We found 581 post-operative device-related complications, which included 206 instances of lead migration, 157 reports of lead erosion, 155 infections, 46 lead-fractures, and 17 lead disconnections. CONCLUSION: The MAUDE data base is a useful tool to investigate device related complications and helps fill the current gap in ONS data. Reviewing the types and frequencies of complications reported over the years allows clinicians with less personal experience to have a more realistic expectation of complications and make informed decisions based on the patient's unique needs. Additionally, patient complaint data are useful in establishing more realistic expectations for patient outcomes.

Occipital nerve stimulation.

Occipital nerve stimulation (ONS) is a form of neuromodulation therapy aimed at treating intractable headache and craniofacial pain. The therapy utilizes neurostimulating electrodes placed subcutaneously in the occipital region and connected to a permanently implanted programmable pulse generator identical to those used for dorsal column/spinal cord stimulation. The presumed mechanisms of action involve modulation of the trigeminocervical complex, as well as closure of the physiologic pain gate. ONS is a reversible, nondestructive therapy, which can be tailored to a patient's individual needs. Typically, candidates for successful ONS include those patients with migraines, Chiari malformation, or occipital neuralgia. However, recent MRSA infections, unrealistic expectations, and psychiatric comorbidities are generally contraindications. As with any invasive procedure, complications may occur including lead migration, infection, wound erosion, device failure, muscle spasms, and pain. The success of this therapy is dependent on careful patient selection, a preimplantation trial, meticulous implantation technique, programming strategies, and complication avoidance.

The use of deep brain stimulation in Tourette's syndrome.

Tourette's syndrome (TS) is a childhood neuropsychiatric disorder characterized by multiple involuntary motor and vocal tics. It is commonly associated with other behavioral disorders including attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, anxiety, depression, and self-injurious behaviors. Tourette's syndrome can be effectively managed with psychobehavioral and pharmacological treatments, and many patients experience an improvement in tics in adulthood. However, symptoms may persist and cause severe impairment in a small subset of patients despite available therapies. In recent years, deep brain stimulation (DBS) has been shown to be a promising treatment option for such patients. Since the advent of its use in 1999, multiple targets have been identified in DBS for TS, including the medial thalamus, globus pallidus internus, globus pallidus externus, anterior limb of the internal capsule/nucleus accumbens, and subthalamic nucleus. While the medial thalamus is the most commonly reported trajectory, the optimal surgical target for TS is still a topic of much debate. This paper provides a review of the available literature regarding the use of DBS for TS.

Thoracic radiculopathy following spinal cord stimulator placement: case series.

OBJECTIVE: The clinical entity of thoracic radiculopathy following spinal cord stimulator (SCS) placement has not been previously described. MATERIALS AND METHODS: A retrospective review of prospectively acquired data on 172 patients, having undergone thoracic SCS placement at our institution, was performed. In addition, four patients were implanted at outside institutions, and were referred for revision. We examine our early experience with placement of thoracic SCS in surgically treated patients with chronic pain and 15 associated specific postoperative radicular pain complications along respective thoracic dermatomes. We postulate that preexisting thoracic spinal pathology affords less compliance in the placement of larger paddles, and subsequent radicular pain in a band-like abdominal fashion. RESULTS: A syndrome of thoracic radiculopathy, presenting as intractable lower thoracic or abdominal wall pain occurring in the immediate postoperative period, was identified in 15 patients. These patients subsequently underwent revision surgery, with either a more extensive laminectomy to further decompress the dorsal nerve roots or lead removal, both of which resulted in near immediate relief of symptoms. CONCLUSIONS: Thoracic radiculopathy may occur following SCS paddle lead placement. This clinical syndrome is characterized by its immediate postoperative development, band-like thoracic or abdominal pain pattern, severe pain that both overwhelms the incisional pain and is refractory to medications, and absence of motor deficit. The lateral placement of paddle leads increases the risk of radicular symptoms. Preoperative thoracic spine magnetic resonance imaging may be helpful in identifying patients who may be susceptible to this syndrome.

The use of intraoperative electrophysiology for the placement of spinal cord stimulator paddle leads under general anesthesia.

BACKGROUND: Placement of spinal cord stimulating paddle leads has traditionally been performed under local anesthesia with intravenous sedation to allow intraoperative confirmation of appropriate placement. It may be difficult to maintain appropriate sedation in certain patients because of medical comorbidities. Furthermore, patients undergoing lead revision frequently have extensive epidural scarring, requiring multilevel laminectomies to place the electrode appropriately. OBJECTIVE: To report our technique of neurophysiologic monitoring that allows these procedures to be performed under general anesthesia. METHODS: Data from 78 patients who underwent electromyography during laminectomy for paddle lead placement were retrospectively reviewed. Seventy patients presented for first-time permanent system placement after a successful trial, and 8 were referred for revision or replacement of previously functioning systems. Surgeries were performed under general anesthesia with fluoroscopic guidance. Electromyography was used to help define the physiological midline of the spinal cord and to guide appropriate lead placement. Somatosensory evoked potentials were used as an adjunct to minimize the possibility of neural injury. RESULTS: Immediately postoperatively, 75 of 78 patients reported that the paresthesia coverage was as good as (or better than) that of the spinal cord stimulation trial. At the long-term follow-up, 1 system was removed for infection, and 6 systems were explanted for lack of efficacy. A total of 64 of the 78 implanted patients reported continued pain relief with stimulator use. Revision surgery was performed in 9 patients. CONCLUSION: The use of intraoperative electrophysiology for the placement of spinal cord stimulation paddle leads under general anesthesia is a safe and efficacious alternative to awake surgery.

Peripheral neurostimulation for the treatment of refractory cluster headache, long-term follow-up: case report.

INTRODUCTION: Cluster headache is a headache syndrome characterized by periodic episodes of intense headache with spontaneous remission. There are recent reports utilizing occipital nerve stimulation for the successful management of medically refractory cases of cluster headache. METHODS: The case of an 18-year-old boy with chronic, refractory, recurrent cluster headaches is presented. He was treated surgically with combined occipital, supraorbital, and infraorbital nerve stimulation. RESULTS: Prior to operation, the patient suffered three to four episodes of cluster headache per day, for four years. After implantation of occipital, supraorbital, and infraorbital nerve stimulators, the patient averages at most three to four headaches per month, at 36-month follow-up. CONCLUSION: Peripheral neurostimulation is safe and efficacious in the management of chronic, medically refractory cluster headache syndrome. The efficacy of treatment was found to be persistent after three years.

A technique of distal to proximal revision of peripheral neurostimulator leads: technical note.

BACKGROUND: Peripheral nerve stimulation for chronic pain states is a safe and efficacious technique, being used with increasing frequency. The incidence of hardware-related complications requiring revision remains high. OBJECTIVES: The authors describe a technique of distal to proximal neurostimulator lead revision, which does not require the changing of generators or extension leads, and thus presumably will minimize further device-related complications. METHODS: The authors present a case series of 3 patients where the distal to proximal neurostimulator lead revision technique was utilized. RESULTS: The technique was well tolerated in each instance and all patients reported >50% pain reduction at long-term follow-up. CONCLUSIONS: The distal to proximal neurostimulator lead revision technique quickly and safely adjusts lead position, including both lead depth and lead tip location, without a need for replacement of components or revision of the entire system.