The Neurostimulation Appropriateness Consensus Committee (NACC)®: Recommendations for the Mitigation of Complications of Neurostimulation.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise and international representation to establish evidence-based guidance on the mitigation of neuromodulation complications. This Neurostimulation Appropriateness Consensus Committee (NACC)® project intends to update evidence-based guidance and offer expert opinion that will improve efficacy and safety. 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 NACC last published guidelines) to October 2023. 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 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 mitigation of complications associated with neurostimulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be used as a guide to assist decision-making when clinically appropriate.

Pain as a disease in the new International Classification of Diseases (ICD-11): Latin American expert consensus.

Aims: Pain diagnoses in the 10th version of the International Classification of Diseases (ICD-10) did not adequately support the current management of pain. Therefore, we aimed to review the new 11th revision (ICD-11) in order to analyze its usefulness for the management, coding, research and education of chronic pain from a Latin American perspective. Methods: The Latin American Federation of Associations for the Study of Pain convened a meeting of pain experts in Lima, Peru. Pain specialists from 14 Latin American countries attended the consensus meeting. Results: In ICD-11, chronic pain is defined as pain that persists or recurs longer than 3 months and is subdivided into seven categories: chronic primary pain and six types of chronic secondary pain. Chronic primary pain is now considered a disease in itself, and not a mere symptom of an underlying disease. Conclusion: The novel definition and classification of chronic pain in ICD-11 is helpful for better medical care, research and health statistics. ICD-11 will improve chronic pain management in Latin American countries, for both the pain specialist and the primary care physician.

Chronic pain is one of the most frequent reasons for medical consultation in Latin America. In the tenth revision of the International Classification of Diseases and Related Health Problems (ICD-10), chronic pain was not adequately defined and individual pain diagnoses were poorly defined. For the first time in Latin America, a meeting of pain experts analyzed and reviewed the 11th version of the International Classification of Diseases (ICD-11), when the Latin America Federation of Associations for the Study of Pain organized a meeting of experts from 14 Latin American countries. In ICD-11, chronic pain is recognized as a biopsychosocial phenomenon and defined as pain that continues or returns for more than 3 months. It is split into seven types: chronic primary pain and six types of chronic secondary pain. In ICD-11, chronic primary pain is now considered a disease in itself, not a mere manifestation of other disease. Our article is the first to address the problems, challenges and benefits of using ICD-11 from a Latin American perspective. It will help to facilitate and disseminate the use of this new classification of chronic pain. This will improve chronic pain treatment, statistics, research and development of better health strategies for pain management in Latin America.

Bilateral Globus Pallidus Externus Deep Brain Stimulation for the Treatment of Refractory Tourette Syndrome: An Open Clinical Trial.

OBJECTIVES: We have previously proposed that Tourette syndrome (TS) is the clinical expression of the hyperactivity of globus pallidus externus (GPe) and various cortical areas. This study was designed to test this hypothesis by verifying the efficacy and safety of bilateral GPe deep brain stimulation (DBS) for treating refractory TS. MATERIALS AND METHODS: In this open clinical trial, 13 patients were operated on. Target coordinates (center of GPe) were obtained by direct visualization. Physiological mapping was performed with macrostimulation and microrecording. Primary and secondary outcome measures were, respectively, responder and improvement rates of TS and comorbidities, according to pre- and postoperative scores on the following assessment instruments: Yale Global Tic Severity Scale, Yale-Brown Obsessive Compulsive Scale, Beck Depression Inventory/Hamilton Depression Rating Scale, Beck Anxiety Inventory/Hamilton Anxiety Rating Scale, and Concentrated Attention test. RESULTS: Intraoperative stimulation (100 Hz/5.0V) did not produce any adverse effects or impact on tics. Microrecording revealed bursting cells discharging synchronously with tics in the central part of the dorsal half of GPe. Patients were followed up for a mean of 61.46±48.50 months. Responder rates were 76.9%, 75%, 71.4%, 71.4%, and 85.7%, respectively, for TS, obsessive-compulsive disorder (OCD), depression, anxiety, and attention deficit hyperactivity disorder. Mean improvements among responders in TS, OCD, depression, and anxiety were 77.4%, 74.7%, 89%, and 84.8%, respectively. After starting stimulation, tic improvement was usually delayed, taking up to ten days to manifest. Afterward, it increased over time, usually reaching its maximum at approximately one year postoperatively. The best stimulation parameters were 2.3V to 3.0V, 90 to 120 µsec, and 100 to 150 Hz, and the most effective contacts were the two dorsal ones. Two complications were registered: reversible impairment of previous depression and transient unilateral bradykinesia. CONCLUSIONS: Bilateral GPe-DBS proved to be low risk and quite effective for treating TS and comorbidities, ratifying the pathophysiological hypothesis that led to this study. Moreover, it compared favorably with DBS of other targets currently in use.

What Is New in the Clinical Management of Low Back Pain: A Narrative Review.

Low back pain (LBP) is a prevalent condition associated with disability. Treating patients with LBP becomes further complicated by the potential presence of underlying conditions, such as cancer or traumatic injury, or biopsychosocial aspects. LBP usually has a neuropathic component that must be assessed and treated appropriately. Pharmacological management of LBP requires a thorough knowledge of the available agents and the mechanisms of the LBP. Although there are effective pharmacological treatments for LBP, it is important to consider safety issues. Fixed-dose combination products may be helpful, as they can reduce opioid consumption without sacrificing analgesic benefits. Neuromodulation is an important and sometimes overlooked treatment option for LBP and may be appropriate for chronic LBP requiring long-term treatment. Imaging studies support neuroplastic changes in the brain as a result of neuromodulation. Interventional approaches to chronic LBP are numerous and must be appropriately selected based on the individual patient. Evidence in support of epidural injections for LBP is strong for short-term pain control but moderate to limited for long-term relief. Rehabilitation for LBP can be an important element of long-term care, and new forms of rehabilitation programs are being developed using telemedicine. A variety of new and established treatments are available for patients with LBP, and clinicians and patients may benefit from emerging new treatment modalities.

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.

Impacto de la Pandemia de COVID-19 en la Práctica de la Neuromodulación en Argentina / Impact of the COVID-19 Pandemic on the Practice of Neuromodulation in Argentina

Introducción: El objetivo de este estudio fue evaluar el impacto de la pandemia de Covid-19 en la práctica de la Neuromodulación en Argentina. Material y Métodos: Se envió una encuesta a los profesionales que practican la Neuromodulación en Argentina entre el 19 de julio al 20 de agosto de 2020. Se determinó el impacto de Covid-19 a nivel profesional y personal. Todas las variables fueron comparadas y analizadas. Resultados: Veinticuatro profesionales respondieron a la encuesta completa. La mayoría de ellos eran varones (87,5%), en el grupo de edad de 45 a 59 años (37,5%), con 15 o más años de experiencia (45,83%). Los neurocirujanos fueron la mayoría (87,5%), siendo las técnicas ablativas la práctica predominante (26,47%). La gran mayoría informó una disminución de las prácticas quirúrgicas (83,33%), entre el 50 y el 74% de ellas (40%), siendo la decisión del financiador la razón única más citada (43,47%) y la Estimulación Cerebral Profunda, la técnica quirúrgica más afectada (41,6%). El 100% de los entrevistados declaró que los pacientes habían sido perjudicados por la suspensión de cirugías y que los ingresos económicos se redujeron de alguna manera, también en el 100% de los encuestados. A nivel personal, ninguno de los profesionales reportaron haber sido diagnosticados de la enfermedad. Sin embargo, el 37,5% sufrió algún otro tipo de daño a nivel físico y el 20,83% informó secuelas psicológicas, especialmente ansiedad. Conclusión: La actual pandemia de Covid-19 ha tenido un impacto muy significativo en la práctica de la Neuromodulación en Argentina, tanto a nivel profesional como personal. Este impacto debe ser tenido en cuenta en el futuro, en caso de una nueva pandemia, para prevenir los efectos nocivos que se registraron en este estudio

Background: The objective of this study was to evaluate the impact of the Covid-19 outbreak in the practice of Neuromodulation in Argentina. Methods: A survey was sent to Argentina neuromodulation practitioners from July 19 to August 20, 2020. The impact of Covid-19 on the professional and personal level were determined. All variables were compared and analyzed. Results: Twenty-four practitioners responded to the complete survey. Most of them were male (87.5%), in the 45-59 year age group (37.5%), with 15 or more years of experience (45.83%). Neurosurgeons were in the majority (87.5%), with ablative techniques being the predominant practice (26.47%). The great majority reported a decrease in surgical practices (83.33%), between 50 and 74% of them (40%), with the decision of the financer being the most cited reason (43.47%), and Deep Brain Stimulation the most affected surgical technique (41.6%). 100% of the interviewed declared that the patients had been harmed by the suspension of surgeries, and that the economic income was reduced in some way in 100% of the interviewed. On a personal level, none of the professionals reported having been diagnosed with the disease. However, 37.5% suffered physical manifestations, and 20.83% reported psychological sequelae, especially anxiety. Conclusion: The current Covid-19 pandemic yielded a significant impact on the daily work practice as well as on the personal level of practitioners in neuromodulation in Argentina. This impact must be taken into account in the long term to avoid further harmful effects and their sequels and to take appropriate preventive measures in the event of another pandemic

Successful Unilateral Surgical Approach to Internal Globus Pallidus and Ventral Intermediate Nucleus of the Thalamus in 3 Cases of Myoclonus-Dystonia Syndrome.

Surgical approaches of internal globus pallidus (GPi) and ventral intermediate thalamic nucleus (Vim) have been used to treat different movement disorders. Three subjects with myoclonus-dystonia syndrome were surgically treated, one of them with GPi and Vim stimulation, while radiofrequency ablation of these structures was performed in the other 2 subjects. Surgical approach of both targets was performed simultaneously on each subject. Mean follow-up was of 33.3 months (22-48 months), the Unified Myoclonus Rating Scale action myoclonus (AM), functional tests (FT), patient questionnaire (PQ) sub-scores, and the Unified Dystonia Rating Scale (UDRS) were used during assessments. Improvement in all scales were seen 6 months after surgery (AM: 74%, FT: 60%, PQ: 63%, UDRS: 65%), and this benefit persisted throughout follow-up (AM: 61%, FT:62%, PQ: 65%, UDRS: 86%). No adverse events were noticed. Simultaneous unilateral procedures of GPi and Vim by either stimulation or ablation techniques improve both motor and functional scores in myoclonus-dystonia syndrome.

Latin American and Caribbean consensus on noninvasive central nervous system neuromodulation for chronic pain management (LAC2-NIN-CP).

INTRODUCTION: Chronic pain (CP) is highly prevalent and generally undertreated health condition. Noninvasive brain stimulation may contribute to decrease pain intensity and influence other aspects related to CP. OBJECTIVE: To provide consensus-based recommendations for the use of noninvasive brain stimulation in clinical practice. METHODS: Systematic review of the literature searching for randomized clinical trials followed by consensus panel. Recommendations also involved a cost-estimation study. RESULTS: The systematic review wielded 24 transcranial direct current stimulation (tDCS) and 22 repetitive transcranial magnetic stimulation (rTMS) studies. The following recommendations were provided: (1) Level A for anodal tDCS over the primary motor cortex (M1) in fibromyalgia, and level B for peripheral neuropathic pain, abdominal pain, and migraine; bifrontal (F3/F4) tDCS and M1 high-definition (HD)-tDCS for fibromyalgia; Oz/Cz tDCS for migraine and for secondary benefits such as improvement in quality of life, decrease in anxiety, and increase in pressure pain threshold; (2) level A recommendation for high-frequency (HF) rTMS over M1 for fibromyalgia and neuropathic pain, and level B for myofascial or musculoskeletal pain, complex regional pain syndrome, and migraine; (3) level A recommendation against the use of anodal M1 tDCS for low back pain; and (4) level B recommendation against the use of HF rTMS over the left dorsolateral prefrontal cortex in the control of pain. CONCLUSION: Transcranial DCS and rTMS are recommended techniques to be used in the control of CP conditions, with low to moderate analgesic effects, and no severe adverse events. These recommendations are based on a systematic review of the literature and a consensus made by experts in the field. Readers should use it as part of the resources available to decision-making.

Deep Brain Stimulation Surgery for Parkinson Disease Coexisting With Communicating Hydrocephalus: A Case Report.

We report a successful bilateral globus pallidus internus-deep brain stimulation (GPi-DBS) for a Parkinson disease (PD) patient with idiopathic normal pressure hydrocephalus (INPH) and an unusually long anterior commissure-posterior commissure (AC-PC) line. A 54-year-old man presented with a history of 3 months of severe shuffling gait, rigidity, slow movements of the left side limbs, and difficulty managing finances. A brain MRI revealed marked ventriculomegaly (Evans index = 0.42). The patient was diagnosed with INPH and a ventriculoperitoneal shunt was placed. Cognitive impairment improved, but walking disturbances, slowness, and rigidity persisted. Then treatment with levodopa was added, and the patient experienced a sustained improvement. He was diagnosed with PD. After 7 years, the patient developed gait freezing and severe levodopa-induced dyskinesia. The patient underwent bilateral GPi-DBS. We used MRI/CT fusion techniques for anatomical indirect targeting. Indirect targeting is based on standardized stereotactic atlas and on a formula-derived method based on AC-PC landmarks. The AC-PC line was 40 mm (the usual length is between 19 and 32 mm). Intraoperative microelectrode recording was a non-expendable test, but multiple recordings were avoided to reduce the surgical risk of ventricular involvement. There was a 71% decrease in the UPDRS III score during the on-stimulation state (28 to 8). The patient's dyskinesias resolved dramatically with a UdysRS of 15 (88% improvement) during the on-stimulation condition. The observed motor benefits and the improvement of his daily activities have persisted 6 months after surgery. Deep brain stimulation surgery in PD with ventriculomegaly is a challenge. This procedure can result in a greater chance of breaching the ventricle, with risks of intraventricular hemorrhage and migration of cerebrospinal fluid into the brain parenchyma with target displacement. Furthermore, clinical judgment is paramount when recent onset of shuffling gait coexists with ventriculomegaly because the most common dilemma is differentiating between PD and INPH. For these reasons, neurologists and surgeons may refuse to operate on PD patients with ventriculomegaly. However, DBS should be considered for PD patients with motor complications when responsiveness to levodopa is demonstrated, even in the context of marked ventriculomegaly.

Remarkable clinical improvement with bilateral globus pallidus internus deep brain stimulation in a case of Lesch-Nyhan disease: five-year follow-up.

OBJECTIVES: Lesch-Nyhan disease (LND) is a hereditary disorder characterized by hyperuricemia, self-mutilation, developmental retardation, and movement disorders such as spasticity and dystonia. The lack of a precise understanding of the neurological dysfunction has precluded the development of useful conservative therapies. We present our experience treating a LND patient by bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) with improvement in dystonia symptoms and disappearance of self-injurious behavior. METHODS: We present a 29-year-old patient characterized by generalized severe dystonia and self-injurious behavior, both refractory to conservative treatment. The patient underwent a GPi bilateral electrode implant for chronic stimulation. Symptoms were evaluated with the Burke-Fhan-Marsden Dystonia Rating Scale (BFMDRS) and Mean Disability Scale (MDS) preoperatively and during the five-year follow-up. RESULTS: We observed a remarkable improvement in dystonia symptoms and complete disappearance of self-injurious behavior. CONCLUSIONS: This case supports the hypothesis that automutilation in LND might be related to dysfunction of the basal ganglia circuits and the idea that bilateral GPi-DBS is a safe and effective treatment modality for this condition.

Acute treatment of trigeminal neuralgia with onabotulinum toxin A.

A double-blind, randomized, placebo-controlled study of patients with essential trigeminal neuralgia and treatment with a single injection of onabotulinum toxin A (BTX) was carried out. The efficacy, safety, and tolerability of either 1 mL 0.9% saline plus 50 U of BTX or only 1 mL of 0.9% saline injected subcutaneously in the affected area were evaluated. Cases with involvement of the third branch of the trigeminal nerve also received intramuscularly either 10 U of BTX or matching placebo in the masseter muscle, ipsilateral to the pain location. Pain was assessed with the visual analog scale (VAS). Twenty subjects were administered BTX, and 16 subjects received placebo. Two months after the intervention, a trend to statistical significance was observed for the VAS mean values in subjects treated with BTX and those who received placebo (VAS 4.9 vs 6.63, t test, P = 0.07). Three months after the injection, significant differences were observed in the average VAS score for subjects treated with BTX and those treated with placebo (VAS 4.75 vs 6.94, respectively; t test, P = 0.01). Onabotulinum toxin A was well tolerated and seems to be a safe and useful therapy for patients with essential trigeminal neuralgia.

Electrical stimulation of the inferior thalamic peduncle in the treatment of major depression and obsessive compulsive disorders.

OBJECTIVE: Stimulation of the inferior thalamic peduncle (ITP) is emerging as a promising new therapeutic target in certain psychiatric disorders. The circuitry that includes the nonspecific thalamic system (NSTS), which projects via the ITP to the orbitofrontal cortex (OFC), is involved in the physiopathology of major depression disorder (MDD) and obsessive compulsive disorder (OCD). The safety and efficacy of chronic ITP stimulation in cases of MDD and OCD refractory to medical treatment is presented. MATERIALS AND METHODS: Six patients with OCD and one with MDD were implanted with tetrapolar deep brain stimulation electrodes in the ITP (x = 3.5 mm lateral to the ventricular wall, y = 5 mm behind the anterior commissure, and z = at the intercommissural plane, i.e., anterior commissure-posterior commissure [AC-PC] level). The effect of chronic stimulation at 130 Hz, 450 µs, and 5.0 V on OCD was evaluated before and 3, 6, and 12 months after initiation of electrical stimulation through the Yale-Brown Obsessive Compulsive Scale, Hamilton Depression Rating Scale, and Global Assessment of Function scale. RESULTS: Chronic ITP electrical stimulation in OCD patients decreased the mean Yale-Brown Obsessive Compulsive Scale score to around 51% for the group at the 12-month follow-up, and increased the mean Global Assessment of Function scale score to 68% for a significant improvement (P = 0.026). Three of 6 patients returned to work. The Hamilton Depression Rating Scale score of the only patient with MDD treated to date went from 42 to 6. This condition of the patient, who had been incapacitated for 5 years prior to surgery, has not relapsed for 9 years. Three OCD patients with drug addiction continued to consume drugs in spite of their improvement in OCD. CONCLUSION: Deep brain stimulation in the ITP is safe and may be effective in the treatment of OCD. A multicenter evaluation of the safety and efficacy of ITP in OCD is currently in process.

Behavioral and motor improvement after deep brain stimulation of the globus pallidus externus in a case of Tourette's syndrome.

OBJECTIVES: The objective of our paper is to show the partial decrease of therapeutic effect with battery exhaustion in a previously successfully treated patient with refractory Tourette's syndrome (TS). MATERIALS AND METHODS: We present a 47-year-old patient diagnosed with TS based on the TS Study Group Criteria and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Surgery was considered based on refractoriness to conservative management. Presurgical evaluation included magnetic resonance imaging (MRI), positron emission tomography scan, and neuropsychologic, neurologic, and psychiatric tests utilizing Yale Brown Obsessive Compulsive Scale, Yale Global Tics Severity Scale, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Global Assessment of Functioning Scale, and Mini-mental State Examination. Target coordinates were obtained from inversion recovery MRI. Quadripolar deep brain stimulation (DBS) electrodes were implanted bilaterally in the globus pallidus externus (GPe) and connected to the pulse generator in the same procedure. To determine the clinical response to DBS, the scores of the scales obtained preoperatively were compared with those obtained postoperatively. RESULTS: No surgical complications were detected and according to the clinical scales the patient experienced a marked improvement of his symptoms, although he never showed obsessive-compulsive disorder components of any type. The battery was exhausted after two years with the subsequent significant partial loss of therapeutic effect. CONCLUSIONS: GPe seems to be a highly promising target of DBS for the treatment of medically refractory TS. After battery exhaustion, the patient experienced a marked partial decrease in the therapeutic effect, which confirms the beneficial action of this method.

Micro lesion effect of the globus pallidus internus and outcome with deep brain stimulation in patients with Parkinson disease and dystonia.

To determine whether the immediate response to electrode implantation (micro lesion effect, MLE) in the internal segment of the globus pallidus (GPi) predicts symptom improvement with deep brain stimulation (DBS) at 6 months in patients with Parkinson's disease (PD) or generalized dystonia. Electrode implantation in the subthalamic nucleus (STN) prior to electrical stimulation has been reported to predict a beneficial effect of DBS in patients with PD, but whether this is also the case for the GPi in either PD or dystonia patients has not been established. We studied 20 patients (11 with PD and 9 with dystonia) who underwent electrode implantation in the GPi. Effects were assessed using standardized scales after 24 hours, weekly for 3 weeks prior to starting DBS, and after 6 months of DBS. 10 of 11 PD and 8 of 9 dystonia cases who benefited from electrode implantation also showed improvement in all motor and disability scores after 6 months of DBS of the GPi. One dystonia patient who did not show MLE benefited from DBS. The presence of MLE after electrode implantation in the GPi may help predict motor benefit from DBS in PD and generalized dystonia patients.

Beneficial effects of botulinum toxin type A in trigeminal neuralgia.

Botulinum toxin has been thoroughly studied as a potential tool in the treatment of several pain syndromes. Therefore, we assessed the clinical effects of botulinum toxin type A injections in 12 patients with otherwise unresponsive idiopathic trigeminal neuralgia. Patients were infiltrated with 20-50 units of botulinum toxin in trigger zones. Those who presented with mandibular involvement were also infiltrated in the masseter muscle. The patients were assessed on a weekly basis using the Visual Analogic Scale for pain. Ten of our patients reported a significant benefit from botulinum toxin injections, with reduction or even disappearance of pain, and remained pain free for as long as 60 days. Our findings suggest that botulinum toxin may represent a useful therapeutic tool in the management of patients with this entity.

Beneficial effects of botulinum toxin type A in trigeminal neuralgia / Beneficio de la toxina botulínica tipo A en neuralgia del trigemino

Botulinum toxin has been thoroughly studied as a potential tool in the treatment of several pain syndromes. Therefore, we assessed the clinical effects of botulinum toxin type A injections in 12 patients with otherwise unresponsive idiopathic trigeminal neuralgia. Patients were infiltrated with 20-50 units of botulinum toxin in trigger zones. Those who presented with mandibular involvement were also infiltrated in the masseter muscle. The patients were assessed on a weekly basis using the Visual Analogic Scale for pain. Ten of our patients reported a significant benefit from botulinum toxin injections, with reduction or even disappearance of pain, and remained pain free for as long as 60 days. Our findings suggest that botulinum toxin may represent a useful therapeutic tool in the management of patients with this entity.

La toxina botulínica ha sido estudiada en forma exhaustiva como una potencial herramienta en el tratamiento de múltiples síndromes dolorosos. Por lo tanto, evaluamos los efectos clínicos de la aplicación de toxina botulínica tipo A en 12 sujetos con neuralgia trigeminal idiopática resistente a manejo farmacológico. Se aplicaron en dichos sujetos entre 20 y 50 unidades de toxina botulínica tipo A en las zonas gatillo. Además se infiltró el músculo masetero en aquellos que presentaban involucro mandibular. Los sujetos fueron evaluados semanalmente con una escala visual análoga para dolor. Diez de los sujetos reportaron un beneficio significativo con el uso de toxina botulínica, con reducción e incluso desaparición del dolor, permaneciendo libres de dolor por un periodo de hasta 60 días. Nuestros hallazgos sugieren que la toxina botulínica puede representar una herramienta terapéutica útil en el manejo de pacientes con esta entidad.

Pallidal surgery for the treatment of primary generalized dystonia: long-term follow-up.

OBJECTIVE: To describe the results and long-term follow-up after functional surgery of the internal segment of the globus pallidus (GPi) in 10 patients with primary generalized dystonia. PATIENTS AND METHODS: Nine of the 10 patients were positive for the DYT1 gene mutation. Bilateral deep brain stimulation (DBS) of the GPi was performed in three cases, bilateral pallidotomy in two, and combined surgery (unilateral GPi lesion with contralateral stimulation) in the remaining five. All patients were evaluated with the Burke-Fahn-Marsden dystonia scale (BFMDS) before, immediately after surgery, at 3 weeks, 3 and 6 months and then yearly. Follow up time ranged from 15 to 105 months (mean: 66.1 months) with six patients having more than 6 years follow up. RESULTS: All patients improved after surgery. All patients with unilateral or bilateral DBS experienced an immediate improvement before starting stimulation. The magnitude of this initial micro lesion effect did not predict the magnitude of the long-term benefit of DBS. The mean decrease in the in the BFMDS was 34%, 55%, and 65% in the movement scale; and 32%, 48%, and 49% in the disability scale for patients with bilateral pallidal DBS, combined unilateral DBS and contralateral pallidotomy, and bilateral pallidotomy, respectively. Worsening of dystonia after a plateau of sustained benefit was observed in three patients. Two patients required multiple pallidal surgeries. Adverse events included: permanent anarthria (1), misplacement of the electrode requiring further surgery (2), scalp infection (1), and hardware related problems (3). CONCLUSIONS: This long-term follow up study confirms the beneficial effect of pallidal DBS or pallidotomy in primary generalized dystonia. In addition, our results extent previous observations by showing that, in these patients, (1) the microlesion effect of DBS is not predictive of long-term benefit; (2) combined DBS with contralateral pallidotomy appears to be more effective than bilateral pallidal DBS; and (3) dystonia can reappear after an initial good response during long term follow up.