The Polyanalgesic Consensus Conference (PACC)®: Intrathecal Drug Delivery Guidance on Safety and Therapy Optimization When Treating Chronic Noncancer Pain.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians and scientists based on expertise with international representation to establish evidence-based guidance on intrathecal drug delivery in treating chronic pain. This Polyanalgesic Consensus Conference (PACC)® project, created more than two decades ago, intends to provide evidence-based guidance for important safety and efficacy issues surrounding intrathecal drug delivery and its impact on the practice of neuromodulation. MATERIALS AND METHODS: Authors were chosen on the basis of 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 PACC® last published guidelines) 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 the strength of evidence or consensus when evidence is scant. RESULTS: The PACC® 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 PACC® recommends best practices regarding intrathecal drug delivery to improve safety and efficacy. The evidence- and consensus-based recommendations should be used as a guide to assist decision-making when clinically appropriate.

Persistent Spinal Pain Syndrome: A Proposal for Failed Back Surgery Syndrome and ICD-11.

OBJECTIVE: For many medical professionals dealing with patients with persistent pain following spine surgery, the term Failed back surgery syndrome (FBSS) as a diagnostic label is inadequate, misleading, and potentially troublesome. It misrepresents causation. Alternative terms have been suggested, but none has replaced FBSS. The International Association for the Study of Pain (IASP) published a revised classification of chronic pain, as part of the new International Classification of Diseases (ICD-11), which has been accepted by the World Health Organization (WHO). This includes the term Chronic pain after spinal surgery (CPSS), which is suggested as a replacement for FBSS. METHODS: This article provides arguments and rationale for a replacement definition. In order to propose a broadly applicable yet more precise and clinically informative term, an international group of experts was established. RESULTS: 14 candidate replacement terms were considered and ranked. The application of agreed criteria reduced this to a shortlist of four. A preferred option-Persistent spinal pain syndrome-was selected by a structured workshop and Delphi process. We provide rationale for using Persistent spinal pain syndrome and a schema for its incorporation into ICD-11. We propose the adoption of this term would strengthen the new ICD-11 classification. CONCLUSIONS: This project is important to those in the fields of pain management, spine surgery, and neuromodulation, as well as patients labeled with FBSS. Through a shift in perspective, it could facilitate the application of the new ICD-11 classification and allow clearer discussion among medical professionals, industry, funding organizations, academia, and the legal profession.

Deep brain stimulation versus pallidotomy for status dystonicus: a single-center case series.

OBJECTIVE: First-line pharmacological therapies have shown limited efficacy in status dystonicus (SD), while surgery is increasingly reported as remediable in refractory cases. In this context, there is no evidence regarding which neurosurgical approach is the safest and most effective. The aim of this study was to assess the clinical outcomes and surgery-related complications of globus pallidus internus deep brain stimulation (GPi DBS) and pallidotomy for the treatment of drug-resistant SD. METHODS: The authors reviewed the records of patients with drug-resistant SD who had undergone GPi DBS or pallidotomy at their institution between 2003 and 2017. The severity of the dystonia was evaluated using the Barry-Albright Dystonia (BAD) Scale. Surgical procedures were performed bilaterally in all cases. RESULTS: Fourteen patients were eligible for inclusion in the study. After surgery, the mean follow-up was 40.6 ± 30 months. DBS ended the dystonic storm in 87.5% of cases (7/8), while pallidotomy had a success rate of 83.3% (5/6). No significant differences were observed between the two techniques in terms of failure rates (risk difference DBS vs pallidotomy -0.03, 95% CI -0.36 to 0.30), SD mean resolution time (DBS 34.8 ± 19 days, pallidotomy 21.8 ± 20.2 days, p > 0.05), or BAD scores at each postoperative follow-up (p > 0.05). The long-term hardware complication rate after DBS was 37.5%, whereas no surgery-related complications were noted following pallidotomy. CONCLUSIONS: The study data suggest that DBS and pallidotomy are equally safe and effective therapies for drug-resistant SD. The choice between the two techniques should be tailored on a case-by-case basis, depending on factors such as the etiology and evolution pattern of the underlying dystonia and the clinical conditions at the moment of SD onset. Given the limitation of the low statistical power of this study, further multicentric investigations are needed to confirm its findings.

Dorsal anterior cingulate cortex (ACC) deep brain stimulation (DBS): a promising surgical option for the treatment of refractory thalamic pain syndrome (TPS).

BACKGROUND: Neuroimaging evidences and previous successful case series of cingulotomy for cancer pain have disclosed the key-role of the dorsal anterior cingulate cortex (ACC) in the generation of the empathic and affective dimension of pain. The aim of this study is to assess the effectiveness and safety of ACC neuromodulation for the treatment of the thalamic pain syndrome (TPS), a chronic neuropathic disease often complicated by severe affective and emotional distress in the long term. METHOD: From January 2015 to April 2017, 5 patients with pure drug-refractory TPS underwent ACC deep brain stimulation (DBS) at our institution. Quantitative assessment of pain and health-related quality of life were performed 1 day before surgery and postoperatively at 6 and 18 months by using the numeric rating scale (NRS), the 36-item short-form health survey (SF-36), and the McGill pain and the EuroQol5-domain questionnaires. RESULTS: Mean age at surgery was 56.2 years (range, 47-66). NRS score improved by 37.9% at 6 months (range, - 22.2 to - 80%) and by 35% at 18 months (range, - 11.1 to - 80%). At the last follow-up, one patient reported a relevant pain reduction (NRS 2), only complaining of mild pain poorly interfering with activities of daily living. Concomitant improvements in the McGill and EuroQol5-domain pain questionnaires, SF-36 total and sub-item scores were also noticed at each follow-up. No surgical or stimulation-related complications occurred during the study period. CONCLUSIONS: ACC DBS may be a safe and promising surgical option to alleviate discomfort and improve the overall quality of life in a patient affected by drug-resistant TPS. Further prospective, larger, and randomized studies are needed to validate these findings.

Staged pallidotomy: MRI and clinical follow-up in status dystonicus.

PURPOSE: We report on a patient affected by Status Distonicus who was treated with Deep Brain Stimulation electrodes implanted in the Globus Pallidus internus (Gpi) and used for serial radiofrequency lesions. MATERIALS AND METHODS: The evolution of radiofrequency lesions was monitored by post-operative and late Magnetic Resonance Imaging (MRI). After the first lesion the patient did improve, though not in a significant fashion. Therefore, three further radiofrequency lesions were delivered 2, 4 and 6 days respectively after surgery with subsequent improvement of dystonic movements. RESULTS: MRI scans performed at 8 days, 3 months, and 6 months after surgery showed a diffuse T2-hyperintense and T1-hypointense GPi signal alteration which progressively decreased over time. CONCLUSION: We confirm that the possibility to stage pallidotomies over time using a couple of new contacts is a safe and efficacious procedure in treating SD patients where the lesions themselves are limited by the appearance of side effects, or in patients showing a poor response to a single lesion. As far as we know, this is the first description of MRI evolution and monitoring of a staged pallidotomy.

Spinal Cord Stimulation for Neuropathic Pain: Current Trends and Future Applications.

The origin and the neural pathways involved in chronic neuropathic pain are still not extensively understood. For this reason, despite the wide variety of pain medications available on the market, neuropathic pain is challenging to treat. The present therapeutic alternative considered as the gold standard for many kinds of chronic neuropathic pain is epidural spinal cord stimulation (SCS). Despite its proved efficacy, the favourable cost-effectiveness when compared to the long-term use of poorly effective drugs and the expanding array of indications and technical improvements, SCS is still worldwide largely neglected by general practitioners, neurologists, neurosurgeons and pain therapists, often bringing to a large delay in considering as a therapeutic option for patients affected by neuropathic chronic pain. The present state of the art of SCS in the treatment of chronic neuropathic pain is here overviewed and speculations on whether to use a trial period or direct implant, to choose between percutaneous leads or paddle electrodes and on the pros and cons of the different patterns of stimulation presently available on the market (tonic stim, high-frequency stim and burst stim) are described.

Multimodal Approach for Radical Excision of Focal Cortical Dysplasia by Combining Advanced Magnetic Resonance Imaging Data to Intraoperative Ultrasound, Electrocorticography, and Cortical Stimulation: A Preliminary Experience.

BACKGROUND AND OBJECTIVE: Type II focal cortical dysplasia is the most common malformation of cortical development associated with drug resistant epilepsy and susceptible to surgical resection. Although, at present, advanced imaging modalities are capable of detecting most cortical disorders, it is still a challenge for the surgeon to visualize them intraoperatively. The lack of direct identification between normal brain and subtle dysplastic tissue may explain the poor results in terms of being seizure-free versus other forms of epilepsy. The aim of this study is to compare magnetic resonance imaging (MRI) and intraoperative ultrasound-guided neuronavigation, along with cortical stimulation and acute electrocorticography, as a multimodal surgical approach to cortical dysplasia's tailored resection. METHODS: Six consecutive patients with type II cortical dysplasia underwent epilepsy surgery by means of MRI/intraoperative ultrasound-guided neuronavigation. Intraoperative cortical stimulation of sensory/motor cortex was performed to localize cortical eloquent areas. Acute electrocorticography was used to identify epileptogenic tissue. These findings were correlated to real-time ultrasound imaging to establish the extent of the resection. RESULTS: Intraoperative ultrasound depicted cortical dysplasias at a higher resolution and accuracy than MRI. Therefore it maximized the extent of the resection. Both postoperative MRIs and pathology documented the extent of the resection in all patients. Seizure-freedom was achieved in 5 cases (Engel class IA), and in 1 patient it was classified as Engel class IB. No postoperative neurological deficits were observed. CONCLUSIONS: These results strongly suggest feasibility of ultrasound-guided resection of focal cortical dysplasia. Providing high resolution and accuracy, it allows an easy, real-time discrimination between normal and dysplastic brain.

Correction to:The innervation of extensor hallucis longus muscle: an anatomical study for selective neurotomy.

The original version of this article unfortunately contained mistakes. The names of all authors are inadvertently inverted and are now corrected in the authorgroup of this article.

Correction to:"Careful" reprogramming of baclofen intrathecal programmable synchromed infusion pumps at their replacement in a series of 156 patients.

The original version of this article unfortunately contained mistakes. The names of all authors are inadvertently inverted and are now corrected in the authorgroup of this article.

Severe Pain and Edema due to a Widespread Lymphangioma: Disappearance of Symptoms and Reduction of Lesion with Spinal Cord Stimulation.

BACKGROUND: The efficacy of epidural spinal cord stimulation on chronic neuropathic pain due to failed back surgery syndrome or nerve root lesions is well reported. There is even literature reporting the effects of spinal cord stimulation in controlling peripheral vascular lesions as in peripheral arteriopathies or diabetic neuropathies and in complex regional pain syndrome type II. This is probably due to an effect of epidural spinal cord stimulation, mainly on the parasympathetic nervous system. CASE DESCRIPTION: A 14- year-old boy affected, since birth, by a quickly growing widespread lymphangioma at the pelvis and right thigh, underwent repetitive surgical procedures to try to reduce its extension. Recurrence always occurred. Due to a massive swelling of his right lower limb and a wide painful area all over the pelvis and right lower limb, the patient lost his autonomy and was almost bedridden or wheelchaired. On January 2015 the patient underwent the implant of a low dorsal epidural 8-lead magnetic resonance imaging (MRI)-compatible electrode connected to an MRI-compatible stimulator. The patient, 1 month after the implantation, had a complete recover of his autonomy, with a marked shrinkage of his right lower limb and a near disappearance of pain. He resumed the activity of the daily living. One year later, a hip MRI showed partial reduction of the lesion. The patient is still nearly free from pain. CONCLUSIONS: This is the first case report of severe chronic pain syndrome due to a widespread lymphangioma successfully treated by means of epidural spinal cord stimulation.

Peripheral Nerve Field Stimulation (PNFS) as a Treatment Option for Intractable Radiation-Induced Facial Neuropathic Pain in a Survivor of Laryngeal Cancer: A Case Report.

BACKGROUND: Treatment-related chronic neuropathic pain represents a major and increasing cause of discomfort in cancer survivors. Unfortunately, in approximately 10%-15% of cases, pain is scarcely relieved by opioids and common painkillers. Thus, alternative measures to manage pain have recently been adopted in these patients. CASE DESCRIPTION: We report the case of a laryngeal cancer survivor who developed an intractable bilateral mandibular radiation-induced neuropathic pain syndrome. His pain was refractory to any pharmacological treatment, whereas the implant of bilateral subcutaneous facial electrodes led to the complete resolution of pain. CONCLUSIONS: To the best of our knowledge, this is the first report in literature describing peripheral nerve field stimulation as a treatment option for intractable cancer treatment-related chronic neuropathic pain. Peripheral nerve field stimulation appears to be a safe and effective procedure.

Epidural spinal cord stimulation for neuropathic pain: a neurosurgical multicentric Italian data collection and analysis.

BACKGROUND: Spinal cord stimulation (SCS) is a technique used worldwide to treat several types of chronic neuropathic pain refractory to any conservative treatment. The aim of this data collection is to enforce evidence of SCS effectiveness on neuropathic chronic pain reported in the literature and to speculate on the usefulness of the trial period in determining the long-term efficacy. Moreover, the very low percentage of undesired side effects and complications reported in our case series suggests that all implants should be performed by similarly well-trained and experienced professionals. METHOD: A multicentric data collection on a common database from 11 Italian neurosurgical departments started 3 years ago. Two different types of electrodes (paddle or percutaneous leads) were used. Of 122 patients, 73 % (N = 89) were submitted to a trial period, while the remaining patients underwent the immediate permanent implant (N = 33). Statistical comparisons of continuous variables between groups were performed. RESULTS: Most of the patients (80 %) had predominant pain to their lower limbs, while only 17 % of patients had prevalent axial pain. Significant reduction in pain, as measured by variation in visual analogue scale (VAS) score, was observed at least 1 year after implantation in 63.8 % of the cases, 59.5 % of patients who underwent a test trial and 71.4 % of patients who underwent permanent implant at once. No statistical differences were found between the lower-limb pain group and the axial pain group. CONCLUSIONS: No relevant differences in long-term outcomes were observed in previously tested patients compared with patients implanted at once. Through this analysis we hope to recruit new centres, to give more scientific value to our results.

Cosmetic posterior implant of internal pulse generators in deep brain stimulation procedures: technical report.

OBJECTIVE: The study aims to describe a novel cosmetic implantation technique of internal pulse generators (IPGs) for deep brain stimulation (DBS) electrodes. MATERIALS AND METHODS: Thirty Parkinson patients during the interval 2001 to 2012 underwent posterior (cervical, dorsal, and lateral subcostal ) subcutaneous implantation of DBS connection cables and IPGs in the prone position. RESULTS: No surgical complications occurred in any of the patients who underwent this procedure; all of the patients reported a high level of satisfaction with the cosmetic results due to the excellent concealment of the implanted devices. CONCLUSIONS: Although this procedure is a little more time consuming compared with the conventional procedure, it is safe and leads to very good cosmetic results in DBS patients, which has significant benefits from the standpoint of social and work activities.

Deep-brain stimulation for aggressive and disruptive behavior.

OBJECTIVE: To describe our institutional experience with deep-brain stimulation (DBS) used in the treatment of aggressive and disruptive behavior refractory to conservative treatment. METHODS: With stereotactic methodology and under general anesthesia, seven patients (from 2002 to 2010) were given DBS in the posterior hypothalamic region, bilaterally, and with the aid of intraoperative microrecording. RESULTS: Six of seven patients presented a clear reduction in the aggression and disruptive bouts, with subsequent simplification of familiar management. CONCLUSIONS: DBS of the posterior hypothalamic region could be an effective treatment for patients affected by mental retardation in whom disruptive and drug-refractory aggressive behavior coexists. Although several experimental data are available on this target, further studies are necessary to confirm the long-term efficacy and safety of this procedure.

Role of intra-operative neurophysiologic monitoring during decompression and neurolysis after peripheral nerve injury: case report.

This paper reports the case of a patient presenting motor and sensitive deficits of the left forearm and hand after a traumatic injury of the median, ulnar, and radial nerves. Decompression and neurolysis of the three nerves was performed. Spontaneous electromyographic activity and the amplitude of compound muscle action potentials (CMAPs) were monitored. Surgery led to an increased amplitude of the aforesaid parameters and a long-term clinical improvement.

Improvement of secondary fixed dystonia of the upper limb after chronic extradural motor cortex stimulation in 10 patients: first reported series.

BACKGROUND: Fixed dystonic postures secondary to ischemic, traumatic, or postsurgical lesions located in the basal ganglia and brainstem constitute a major therapeutic challenge and limit motor rehabilitation efficacy. They are often refractory to conservative treatment. Aberrant cerebral plasticity developed after deep brain lesions is thought to lead to abnormal cortical representation of the affected part of the body and then to pathological fixed postures. OBJECTIVE: To assess the efficacy of motor cortex stimulation in patients with upper limb fixed dystonia. METHODS: Ten patients were submitted to computer-assisted and electromyography-monitored implantation of intracranial epidural electrodes over the central cortical sulcus contralateral to the affected limb. Patients were followed up from 1 to 9 years (9 patients), except for patient 10, whose follow-up was limited to 4 months. RESULTS: Seven of 7 patients showed > 30% improvement in the Disability of Shoulder, Arm, and Hand Scale and an overall 70% increase in the score of the Short Form-36 Physical Activity subscale with significant and stable improvement of quality of life during stimulation. The partial recovery of hand dexterity observed in most of the treated patients additionally contributed to a significant improvement of their quality of life. CONCLUSION: Although the pathophysiology of fixed dystonia is unknown, our results suggest a major role of the motor cortex in this condition and reinforce the hypothesis that postlesional delayed cortical rearrangements might take place in these forms and be the target of effective therapeutic neuromodulation.