Peripheral Nerve Stimulation on the Brachial Plexus With Ultrasound-guided Percutaneous Technique: A Case Series.

INTRODUCTION: The aim of this case series was to assess the safety and effectiveness of peripheral nerve stimulation (PNS) of the brachial plexus performed using a low invasive percutaneous approach with ultrasound guide. MATERIALS AND METHODS: Patients affected by neuropathic pain with a documented brachial plexus partial avulsion were included in this observational study. A totally implantable PNS system specifically designed for peripheral placement (Neurimpulse, Padua, Italy) was implanted and followed for 18 months, recording the level of pain (Numeric Rating Scale [NRS]), therapy satisfaction (Patient Global Impression of Improvement), quality of life (Short Form Health Survey questionnaire), and change in drug consumption and work status. Descriptive statistic (mean and SD) was used to compare pre- and postimplantation differences. RESULTS: A total of 18 patients were included in the observational study; 16 of them proceeded with the permanent implantation. System infection (N = 1) and lead migrations (N = 2) were recorded during a follow-up mean of 14.8 ± 5.4 months. The average NRS reduction at 18 months was 41%. Average quality-of-life physical and mental indexes increased by 14% and 32%, respectively. Drug intake was stopped in 22% and reduced in 56% of the patients. CONCLUSIONS: PNS systems of the brachial plexus implanted with percutaneous approach appear to be safe and effective in a follow-up period of 18 months. Longer and larger studies are needed to confirm and extend these outcomes.

Frameless neuronavigation-assisted brain biopsy with electromagnetic tracking: how I do it?

BACKGROUND: In recent years, thanks to several technological innovations, stereotactic cerebral biopsies have evolved from frame-based to frameless neuronavigation-assisted techniques. METHODS: The authors provide herein a detailed step-by-step description of the technique, shedding light on surgical tips and how to avoid complications. The practical application of the technique is demonstrated with a high-quality video. CONCLUSION: The neuronavigation-assisted brain biopsy with electromagnetic tracking is a "true frameless" procedure. It represents a simple, safe, and effective innovation for frameless biopsy of cerebral lesions. This technique is time efficient, offering a high degree of accuracy required for the establishment of a definitive diagnosis, enabling optimal further treatment, and thus improving patient outcome.

The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations for Surgical Technique for Spinal Cord Stimulation.

INTRODUCTION: The field of neurostimulation for the treatment of chronic pain is a rapidly developing area of medicine. Although neurostimulation therapies have advanced significantly as a result of technologic improvements, surgical planning, device placement, and postoperative care are of equal importance to optimize outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for these often-overlooked areas of neurostimulation practice. MATERIALS AND METHODS: Authors were chosen based on their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from the last NACC publication in 2017 to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on evidence strength and consensus when evidence was scant. RESULTS: This NACC project provides guidance on preoperative assessment, intraoperative techniques, and postoperative management in the form of consensus points with supportive evidence. These results are based on grade of evidence, strength of consensus, and expert opinion. CONCLUSIONS: The NACC has given guidance for a surgical plan that encompasses the patient journey from the planning stage through the surgical experience and postoperative care. The overall recommendations are designed to improve efficacy and the safety of patients undergoing these neuromodulation procedures and are intended to apply throughout the international community.

The Neurostimulation Appropriateness Consensus Committee (NACC): Recommendations on Best Practices for Cervical Neurostimulation.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise with international representation to establish evidence-based guidance on the use of neurostimulation in the cervical region to improve outcomes. This Neurostimulation Appropriateness Consensus Committee (NACC) project intends to provide evidence-based guidance for an often-overlooked area of neurostimulation practice. MATERIALS AND METHODS: Authors were chosen based upon their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to the present. Identified studies were graded using the US Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant. RESULTS: The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The NACC recommends best practices regarding the use of cervical neuromodulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be utilized as a guide to assist decision making when clinically appropriate.

An ancestor of the stereotactic atlases: the Tabulae Anatomicae of Bartolomeo Eustachio.

The authors report the history of the Tabulae Anatomicae of Bartolomeo Eustachio (ca. 1510-1574). In the tables, the anatomical illustrations were drawn inside a numerical frame, with pairs of numbers on the y- and x-axes to identify single anatomical details in the reference table. The measures and the references could be calculated using the graduated margins divided by 5 units for each the x-axis and y-axis. The Tabulae Anatomicae can be considered a precursor to modern anatomical reference systems that are the basis of studies on cerebral localization mainly used for stereotactic procedures.

Effects of Multiple Waveforms on Patient Preferences and Clinical Outcomes in Patients Treated With Spinal Cord Stimulation for Leg and/or Back Pain.

OBJECTIVES: We present the results of a prospective, randomized, crossover, single-blind, study in which each patient is in control of himself. The aim was to evaluate subperception-based (SP-SCS) waveforms in previously implanted spinal cord stimulation (SCS) patients with leg and/or back pain due to failed back surgery syndrome, who experienced only paresthesia-based stimulation (PB-SCS). Patients with PB-SCS experience in SCS was 4.7 years (SD 2.9). MATERIALS AND METHODS: We enrolled 28 consecutive patients. Treatment consisted of seven days of PB-SCS, followed by a randomized, crossover phase to test SP-SCS waveforms (burst or 1 kHz frequency, seven days each). A maximum of three-day washout period separated each stimulation program. RESULTS: Statistically significant pain relief was maintained using both SP-SCS waveforms, as indicated by the differences between the pre-PB-SCS numeric pain rating score (mean 9) and the pain score after using the burst program (pain relief 52%) or the 1 kHz program (pain relief 51%). There was no statistically significant superiority among PB-SCS, burst, and 1 kHz stimulation. Overall, 50% of patients preferred PB-SCS, 42% chose to move to SP-SCS stimulation, one patient was unable to give feedback, and one patient was unsuccessful with any type of stimulation. Overall, SCS has shown to be successful in pain relief and the patients switched to a SP-SCS waveform only for having higher pain relief. CONCLUSIONS: There was a high heterogeneity regarding waveform preference, with patients who preferred to feel the tingling sensation and those who chose a SP-SCS option, mainly for greater pain relief. In general, SCS is successful, resulting in high pain relief, improvements in quality of life, and little depression. Overall, 42% patients benefited from the novel SP-SCS stimulation waveforms.

Comparison of Tonic vs. Burst Spinal Cord Stimulation During Trial Period.

BACKGROUND: Spinal cord stimulation (SCS) is a well-known treatment in patients with failed back surgery syndrome (FBSS). Burst stimulation is a recently developed stimulation modality that seems to be superior to tonic stimulation. METHODS: This observational multicenter study compared tonic and burst stimulation during a trial period in patients with FBSS or radiculopathy. All the patients enrolled underwent two weeks of tonic stimulation followed by another two weeks of BurstDR stimulation, without randomization. The primary outcome was the reduction of pain in the legs and back. Health-related quality of life (EQ-5D) and the pain catastrophizing scale (PCS) were assessed before and after the trial. Patients were reevaluated after 12 months. RESULTS: We recruited 23 patients, 57% of whom had FBSS and 43% had radiculopathies. Five patients failed both the tonic and burst stimulation trials. While tonic stimulation reduced leg pain (p < 0.05), the burst mode added an extra pain reduction (ΔNRS 1.2 ± 1.5) (p < 0.01). No significant reduction in back pain was found (p 0.29). Pain on movement was reduced only by BurstDR (p < 0.01). Both stimulation modalities increased EQ-5D and reduced PCS from the baseline (p < 0.0001). At the end of the SCS trial phase, 26% patients chose tonic SCS, while 74% preferred burst. On 12-month follow-up examination, the benefits recorded at the end of the trial were maintained. CONCLUSIONS: Burst stimulation confers a greater reduction in leg pain intensity at rest and on movement. Reducing axial pain is still a challenge. Further studies are needed in order to provide each patient with the most appropriate stimulation paradigm.

Are Multidimensional Pain Inventory Coping Strategy Profiles Associated with Long-Term Spinal Cord Stimulation Effectiveness?

Introduction: It is acknowledged that the way patients cope with pain may influence treatment outcome. In particular, psychological factors are deemed important when considering patients for suitability for spinal cord stimulation (SCS). Objective: The aim of the study is to observe how pre-implantation psychological characteristics impact the effectiveness of SCS for chronic pain. Methods: The analysis comprised data from 137 patients who underwent an SCS implant. Screening evaluation included a coping strategies profile (Multidimensional Pain Inventory) and psychiatric disorders (Mini-International Neuropsychiatric Interview). Based on SCS implant outcome collected during follow-up visits, patients were divided into three groups: subjects with long-term pain relief (long-term group), subjects who failed the SCS treatment and decided to explant trial device (trial explanter group [TE]), and those who chose a permanent device (permanent explanter group [PE]). Results: Results showed that most of the patients who failed with the SCS (TE and PE groups) demonstrated a dysfunctional coping profile and showed a higher presence of psychiatric disorders, which significantly influenced the experience and perception of pain. Conclusions: The findings of this study support the value of a multidisciplinary screening. Addressing psychological issues before SCS implantation can reduce the failure rate of SCS.

Peripheral Nerve Stimulation in the Treatment of Chronic Pain Syndromes From Nerve Injury: A Multicenter Observational Study.

INTRODUCTION: Assessing the feasibility, technical implications, and clinical benefits of peripheral nerve stimulation (PNS) performed by an implantable pulse generator (IPG) located close to the stimulation site. MATERIALS AND METHODS: Selected patients were affected by neuropathic pain associated with a documented peripheral nerve lesion, refractory to conventional surgical or pharmacological treatment. A PNS system specifically designed for peripheral placement (Neurimpulse, Padova, Italy) was implanted and followed for six months, recording the degree of patient's satisfaction (PGI-I questionnaire), the pain numerical rating scale (NRS) and the quality of life (SF36 questionnaire), as well as any change in drug regimen and work capability. The statistical significance of differences was determined by the paired Student's t-test. RESULTS: A total of 58 patients were referred to permanent IPG implantation. Stimulation failure due to lead damage or dislocation was noticed in two cases (3.4%) in six months. At the follow-up end, the relative NRS reduction averaged -58 ± 30% (p < 10-6 ) and was greater than 50% in 69% of the cases. Quality-of-life physical and mental indices were increased by 18% (p < 0.005) and 29% (p < 0.0005), respectively. The administration of antalgic drugs was stopped in 55% and reduced in 16% of the patients. Low-energy stimulation was possible in most cases, resulting in an IPG estimated life of 80 ± 35 months. CONCLUSIONS: Successful PNS was achieved with a stimulation system designed for peripheral location. This new technology reduced the incidence of lead-related adverse events and the energy cost of the treatment.

Using peripheral nerve stimulation (PNS) to treat neuropathic pain: a clinical series.

OBJECTIVE: We examined the efficacy of peripheral nerve stimulation (PNS) in treating neuropathic and causalgic pain, with a stimulation system specifically designated for PNS itself. MATERIALS AND METHODS: A total of 15 patients were treated between January 2011 and March 2012. The percutaneous lead was implanted on the nerves, exposing it on the electrical nerve stimulation (ENS) guide. The average numeric rating scale (NRS) preimplant was 8.46, and the oxycodone intake was 90 mg/day. RESULTS: Of the 15 patients, 3 failed the trial phase and 12 were implanted with a permanent pulse generator (Lightpulse 100, Neurimpulse, Rubano, PD, Italy). At an average of 9.3 months of follow-up, the average NRS score was 3.46 (p < 0.001), and the average Likert scale score at 7 points was 5.91. Nine patients were working prior to their injuries, seven of whom returned to work after receiving an implant. The average oxycodone consumption decreased to 30 mg/day, and the pregabalin dosage decreased to 75 mg/day. CONCLUSION: Our study results confirm that PNS is an effective modality in managing severe neuropathic and intractable pain following multiple joint surgeries that are complicated by causalgic pain.

A Benefit/Risk Assessment of Intrathecal Ziconotide in Chronic Pain: A Narrative Review.

BACKGROUND: Ziconotide is an intrathecal drug administered for the treatment of chronic pain. The current literature lacks an exhaustive benefit/risk assessment on this drug. We herein focus on Ziconotide's pharmacology and clinical applications. METHODS: Literature research was conducted to identify studies on Ziconotide administration for the treatment of chronic pain, published between January 1990 and March 2023 and located via PubMed, Embase, Medline, Cinahl, and Web of Science, using the following keywords: Ziconotide, Omega conotoxin, Prialt, SNX-111, intrathecal therapy, and neuropathic pain. Only publications written in English were selected. RESULTS: Among the 86 selected studies, we found 4 Randomized Controlled Trials (RCTs) and 3 prospective long-term studies concerning the intrathecal use of Ziconotide as a monotherapy in chronic pain. Other studies described the intrathecal infusion of Ziconotide combined with other drugs. Overall, Ziconotide has been proved to have strong efficacy for relieving chronic pain, although patients with co-morbid psychiatric disorders require a careful monitoring when treated with Ziconotide. CONCLUSIONS: Overall, the use of Ziconotide, as a monotherapy or in conjunction with other therapies for the treatment of chronic pain, was reported to be efficacious. Overall, its use in patients with chronic pain refractory to other pharmacologic agents outweighs the possible adverse consequences, thus resulting in a favorable benefit/risk assessment.

The "state of the art" of intraoperative neurophysiological monitoring: An Italian neurosurgical survey.

Introduction: Intraoperative Neurophysiological Monitoring (IOM) is widely used in neurosurgery but specific guidelines are lacking. Therefore, we can assume differences in IOM application between Neurosurgical centers. Research question: The section of Functional Neurosurgery of the Italian Society of Neurosurgery realized a survey aiming to obtain general data on the current practice of IOM in Italy. Materials and methods: A 22-item questionnaire was designed focusing on: volume procedures, indications, awake surgery, experience, organization and equipe. The questionnaire has been sent to Italian Neurosurgery centers. Results: A total of 54 centers completed the survey. The annual volume of surgeries range from 300 to 2000, and IOM is used in 10-20% of the procedures. In 46% of the cases is a neurologist or a neurophysiologist who performs IOM. For supra-tentorial pathology, almost all perform MEPs (94%) SSEPs (89%), direct cortical stimulation (85%). All centers perform IOM in spinal surgery and 95% in posterior fossa surgery. Among the 50% that perform peripheral nerve surgery, all use IOM. Awake surgery is performed by 70% of centers. The neurosurgeon is the only responsible for IOM in 35% of centers. In 83% of cases IOM implementation is adequate to the request. Discussion and conclusions: The Italian Neurosurgical centers perform IOM with high level of specialization, but differences exist in organization, techniques, and expertise. Our survey provides a snapshot of the state of the art in Italy and it could be a starting point to implement a consensus on the practice of IOM.

Spinal cord stimulation (SCS) in conjunction with peripheral nerve field stimulation (PNfS) for the treatment of complex pain in failed back surgery syndrome (FBSS).

BACKGROUND: Failed back surgery syndrome (FBSS) is a well-defined pathologic condition observed over many years. DESIGN: We have investigated the effect of spinal cord stimulation (SCS) with peripheral nerve field stimulation (PNfS) in eight patients with FBSS. OUTCOME MEASURE: The following parameters were collected and analyzed: The pain intensity score on a 0-10 numbering rating scale (NRS), the psychologic profile with Beck Depression Inventory (BDI), the pain quality with McGill Pain Questionnaire-short form (MGPQ-sf), the back pain with Oswestry scale score (OS), and the health general quality pattern with QualityMetric's SF-36v2(®) Health Survey. PATIENTS: Eight patients with low back and radicular pain in FBSS are reported. The mean duration of pain was 6.7 months, and the mean NRS score was 9.5, BDI 28.8, MGPQ-sf 16.8, OS 44.5, and SF-36 score was 72.8. The average drug intake of opioids was 250 mg/day. INTERVENTION: In six patients, two octopolar leads were placed in epidural space at D7-D8 and D8-D9, in conjunction with two octopolar leads placed in lumbar-sacral subcutaneous space (Precision System, Boston Scientific, Valencia, CA, USA), and in two patients, a two tetrapolar leads was placed in epidural space at D8-D9 with two tetrapolar leads (Pisces Quad, Plus, Medtronic Inc., Minneapolis, MN, USA) placed in lumbar-sacral subcutaneous space (Restore Ultra, Medtronic Inc., Minneapolis, MN, USA). RESULTS: After one year mean of follow-up, the mean NRS score was 4, BDI 8, MGPQ-sf 5, OS 21, and the SF-36 score was increased at 108.5. The mean drug intake of opioids was decreased at 20 mg/day. CONCLUSION: The combination of SCS and PNfS, using the latest rechargeable systems, may be a valid therapeutic strategy in FBSS.

The treatment of persistent spinal pain syndrome with epidural pulsed radiofrequency: improvement of the technique.

Background: In Persistent Spinal Pain Syndrome (PSPS), Pulsed Radiofrequency (PRF) is a used procedure. The results of PRF in PSPS performed with an electrode placed through the sacral hiatus were reported to be successful on pain in only 32% of patients. We have tried to improve the results by applying a new system to PRF. Methods: Ten patients were treated with PRF application through a steerable epidural catheter with a reference electrode outside the foramen. This method was named "Optimization Current Flow" (OCF). The duty cycle of PRF was 2 × 10 msec and total exposure time was 150 s. Follow up was planned for 1, 3, and 6 months. The NRS score was considered to be the primary outcome. Results: In the first 10 patients treatment was successful (69% of the patients) at 6 months follow-up. Conclusion: This new modality of PRF in patients with PSPS seems to be superior to procedures done with a needle. Further prospective double-blind randomized long-term studies with a significant number of patients are required to validate this technique as there is a need to improve PRF results in PSPS.

Pulsed radiofrequency effects on the lumbar ganglion of the rat dorsal root: a morphological light and transmission electron microscopy study at acute stage.

Since the dorsal root ganglia represent the first structure of pain modulation, they are the target of the newest therapies of neuropathic pain. Between these, pulsed radiofrequency (PRF) has been described among the promising non-invasive methods. Although the results encourage the clinical use of this procedure, their mechanism of action is still unclear. Aim of our study was to analyze acute effects of PRF on the rat lumbar ganglion and on nervous fibres running inside it. Clinical works describe PRF treatment as a technique without any visible neurological deficit. The few disposable histological works are contractictory: some describe no signs of cellular damage and some demonstrate visible intracellular modifications. A total of 20 male Wistar rats were deeply anesthesized. Ten were positioned in a stereotactic system, and exposed to PRF at 2 Hz for 30 s after exposition of paravertebral muscles and positioning of a stimulation needle on left L4 ganglion. The other ten were used as controls. After 1 h, the left dorsal root ganglions L3, L4, L5 of the 20 animals were explanted, fixed in 2.5% Karnowsky solution and prepared for light and transmission electron microscopy. At light microscopy no differences between treated and control animals were observed; at transmission electron microscopy, instead, it was possible to observe that T gangliar cells contained an abnormal abundant smooth reticulum with enlarged cisternae and numerous vacuoles; myelinated axons presented pathological features and their myelin coverage was not adherent. Instead, unmyelinated axons appeared normal in shape and dimension and the Schwann cells surrounding it had intact plasmamembrane. Our results, obtained at acute stage, reveal that the PRF procedure should destroy the myelin envelope of nervous fibres. Further future studies, at chronic stage, should give other information on the prognosis of the myelinic damage.

Acute Hydrocephalus Caused by Cerebellar Abscess in HIV-Negative Castleman's Disease.

Castleman's disease (CD) is a rare and indolent hematologic disorder characterized by solitary bulky adenopathy. Multiple nodal nonbulky localizations are described, while central nervous system involvement is rare. Immunodeficiency is associated with higher incidence of CD, and HIV serology should be performed at initial diagnosis. We report the case of a 64-year-old HIV-negative man affected by CD, presenting with acute hydrocephalus caused by a large cerebellar abscess.

Ten-year outcome of vagus nerve stimulation-implanted patients with treatment-resistant depression: two Italian cases.

Over the last 15 years, vagus nerve stimulation (VNS) has been used as an augmentative therapeutic intervention in patients with treatment-resistant depression (TRD), whether with a lifetime diagnosis of major depressive disorder or bipolar disorder. From being a potentially effective treatment in the acute phase of TRD, recently published treatment guidelines seemed to converge on the indication that VNS's greatest benefit may be seen mostly beyond the short term. However, with the exception of a recent multicenter American report, very few studies have assessed the long-term efficacy of VNS in TRD patients. Herein, we present the cases of two Italian patients with TRD, with 10-year VNS follow-up evaluation. Both patients were found to benefit from augmentative VNS, and the latency of their stimulation response, tolerability, associated pharmacological treatment, number and duration of recurrences, and overall level of functioning are described and discussed. Further reports with larger samples are needed to support the long-term efficacy and tolerability of VNS in TRD patients, particularly beyond 5 years of follow-up.

Intrathecal baclofen does not inhibit the growth of different bacterial species and Candida albicans.

BACKGROUND: The antimicrobial activity of intrathecal baclofen was investigated. Several different microorganisms were used: Staphylococcus aureus (beta-lactamase-positive and beta-lactamase-negative strains); S epidermidis; Enterococcus faecalis; Klebsiella pneumoniae; Escherichia coli; Pseudomonas aeruginosa; and Candida albicans. METHODS: Three experimental approaches were used to assess baclofen antimicrobial activity: (1) determination of the MIC; (2) determination of the MBC; and (3) kinetic time-kill assay. Experiments were performed according to current methods of the NCCLS. RESULTS: As compared with control organisms exposed to physiologic saline, organisms exposed to baclofen over a 10-day period failed to reduce the number of viable cells by at least 3 log(10), as requested by NCCLS criteria. CONCLUSIONS: Because the viability of the investigated organisms was not reduced over that of microbial suspensions exposed to physiologic saline, we conclude that intrathecal baclofen has no measurable activity against different bacterial species and C albicans.

Baclofen and potential therapeutic use: studies of neuronal survival.

Up to now, baclofen (a GABA(B) receptor agonist) has been used for the treatment of severe spasticity unresponsive to oral antispasmodics. Although in humans it is usually administered at 2 mg/ml, the dosage to be used in the treatment of other diseases is unknown. For this reason, it is important to determine the safe maximum dosage and toxicity at the clinically used concentration. Primary cortical neurons represent a useful model to test the safety of baclofen. We performed a colorimetric assay (MTT test) as well as electron microscopy investigations, to determine neuronal survival after the treatment with baclofen at a concentration of 2 and 4 mg/ml. Our results demonstrated that, in our experimental model, neither concentration affected neuronal survival. Considering the above results, we can conclude that at the used concentrations, this drug is safe and its clinical use should be encouraged.