Outcomes, complications, and dosing of intrathecal baclofen in the treatment of multiple sclerosis: a systematic review.

OBJECTIVE: The purpose of this systematic review was to evaluate empirical outcomes of studies in the literature that investigated effectiveness of intrathecal baclofen (ITB) in the treatment of multiple sclerosis (MS)-related spasticity (MSRS) based on various metrics. Since the first description of this route of baclofen delivery for MS patients by Penn and Kroin in 1984, numerous studies have contributed to the medical community's knowledge of this treatment modality. The authors sought to add to the literature a systematic review of studies over the last 2 decades that elucidates the clinical impact of ITB in treating MSRS with the following endpoints: impact on patient-centered outcomes, such as spasticity reduction (primary), complications (secondary), and dosing (secondary). METHODS: The authors queried three databases (PubMed, Scopus, and Cochrane Library) using the following search terms: (intrathecal baclofen) AND (multiple sclerosis). The set inclusion criteria were as follows: 1) original, full-text article; 2) written in the English language; 3) published between and including the years 2000 and 2023; 4) discussion of pre- and post-ITB pump implantation outcomes (e.g., reduction in spasticity and improved comfort) in MSRS patients with long-term ITB treatment; and 5) contained a minimum of 5 MS patients. Data on study type, patient demographics, follow-up periods, primary outcomes, and secondary outcomes were extracted from the included studies. RESULTS: The authors' search yielded 465 studies, of which 17 met inclusion criteria. Overall, they found evidence for the effectiveness of ITB in treating MSRS patients whose condition was refractory to oral medications, with significant reported changes in spasm frequency from pre- to postimplantation. They also found evidence supporting the positive impact of ITB on MSRS patients' quality of life. Moreover, the authors found that most complications were surgical rather than pharmacological. In addition, the average 1-year dose of ITB (reported in 7 of the included studies) was 191.93 µg/day, which is substantially lower than ITB doses reported in the literature for patients with central (non-MS) or spinal origins of spasticity at 1-year follow-up. CONCLUSIONS: The evidence supports ITB as a clinically effective treatment for MSRS, particularly in patients in whom oral antispasmodics and physiotherapy have failed. This systematic review contributes a comprehensive synthesis of clinical benefits, complications, and dosing of ITB reported over the past 2 decades, which furthers an understanding of ITB's clinical utility in practice.

Early Experience With New Generation Deep Brain Stimulation Leads in Parkinson's Disease and Essential Tremor Patients.

BACKGROUND: Newer generation deep brain stimulation (DBS) systems have recently become available in the United States. Data on real-life experience are limited. We present our initial experience incorporating newer generation DBS with Parkinson's disease (PD) and essential tremor (ET) patients. Newer systems allow for smart energy delivery and more intuitive programming and hardware modifications including constant current and directional segmented contacts. METHODS: We compared six-month outcomes between 42 newer generation and legacy leads implanted in 28 patients. Two cohorts each included 7 PD patients with bilateral subthalamic nucleus (STN) stimulation and 7 ET patients with unilateral ventral intermediate nucleus (VIM) stimulation of the thalamus. All directional leads included 6172 Infinity 8-Channel Directional leads and Infinity internal pulse generators (Abbott Neuromodulation, Plano, TX, USA) and nondirectional leads included lead 3389 with Activa SC for VIM and PC for STN (Medtronic, Minneapolis, MN, USA). RESULTS: Six-month outcomes for medication reduction and motor score improvements between new and legacy DBS systems in PD and ET patients were similar. Directionality was employed in 1/3 of patients. Therapeutic window (difference between amplitude when initial symptom relief was obtained and when intolerable side effects appeared with the contact being used) was significantly greater in new DBS systems in both PD (p = 0.005) and ET (p = 0.035) patients. The windows for new and legacy systems were 3.60 V ± 0.42 and 2.00 V ± 0.32 for STN and 3.06 V ± 0.44 and 1.85 V ± 0.28 for VIM, respectively. DISCUSSION: The therapeutic window of newer systems, whether or not directionality was used, was significantly greater than that of the legacy system, which suggests increased benefit and programming options. Improvements in hardware and programming interfaces in the newer systems may also contribute to wider therapeutic windows. We expect that as we alter workflow associated with newer technology, more patients will use directionality, and amplitudes will become lower.

Characterization and Treatment of Unilateral Facial Muscle Spasm in Linear Scleroderma: A Case Report.

Background: Linear scleroderma has been associated with muscle spasms ipsilateral to skin lesions. Typically, spasms are located in trigeminal innervated muscles, leading to hemimasticatory spasm (HMS). Case Report: We report a case of linear scleroderma associated with spasm of muscles innervated not only by the trigeminal but also by the facial nerve. Discussion: We review the patient's successful treatment with incobotulinumtoxinA, a formulation of botulinum toxin that has not been reported for use in this condition.

Clinical Outcome and Characterization of Local Field Potentials in Holmes Tremor Treated with Pallidal Deep Brain Stimulation.

BACKGROUND: Holmes tremor (HT) is an irregular, low-frequency rest tremor associated with prominent action and postural tremors. Currently, the most effective stereotactic target and neurophysiologic characterization of HT, specifically local field potentials (LFPs) are uncertain. We present the outcome, intraoperative neurophysiologic analysis with characterization of LFPs in a patient managed with left globus pallidus interna deep brain stimulation (Gpi DBS). CASE REPORT: A 24-year-old male underwent left Gpi DBS for medically refractory HT. LFPs demonstrated highest powers in the delta range in Gpi. At the 6-month follow-up, a 90% reduction in tremor was observed. DISCUSSION: Pallidal DBS should be considered as an alternative target for management of refractory HT. LFP demonstrated neuronal activity associated with higher power in the delta region, similarly seen in patients with generalized dystonia.

Prospective Study Evaluating IncobotulinumtoxinA for Cervical Dystonia or Blepharospasm: Interim Results from the First 145 Subjects with Cervical Dystonia.

BACKGROUND: We report the interim results from XCiDaBLE, a large, prospective, observational "naturalistic" study evaluating Xeomin® (incobotulinumtoxinA) for Cervical Dystonia or BLEpharospasm in the United States. METHODS: Subjects (≥ 18 years old) with cervical dystonia (CD) are followed for two treatment cycles and monitored via Interactive Voice/Web Response. The subject's physician must have chosen to treat with incobotulinumtoxinA prior to and independent of enrollment in this study. Subject-reported scales include the Subject Global Impression-Severity and Improvement and Cervical Dystonia Impact Profile (CDIP-58), and Work Productivity and Quality of Life (QoL) are assessed by means of an employment questionnaire and work history and the SF-12v2 Health Survey (SF-12v2). Subjects are seen by the investigator for three visits, which include a baseline visit (including the first injection), a second injection visit, and a final study visit (12 weeks after the second injection). RESULTS: This ongoing study includes 145 subjects with a diagnosis of CD. The majority were female (82.3%) and white (91.0%) and had previously been treated with botulinum toxins (77.2%). There were 106 employed at the time of disease onset, but 12.6 years later only 44% were still employed at the time of enrolment into the study, and 20% were either receiving or seeking disability benefits. The mean total dose/treatment of CD was 225.2 units for the first injection. The CDIP-58 total score was significantly improved 4 weeks after the first injection compared to baseline (p≤0.0001). Most subjects noted improvement in their global impression assessment. No new or unexpected adverse events occurred. DISCUSSION: The results from these interim analyses confirm previous controlled, single-dose studies of incobotulinumtoxinA in terms of efficacy and safety.

Efficacy and safety of botulinum type A toxin (Dysport) in cervical dystonia: results of the first US randomized, double-blind, placebo-controlled study.

Botulinum toxin type A (Dysport) has been shown in European studies to be a safe and effective treatment for cervical dystonia. This multicenter, double-blind, randomized, controlled trial assessed the safety and efficacy of Dysport in cervical dystonia patients in the United States. Eighty patients were randomly assigned to receive one treatment with Dysport (500 units) or placebo. Participants were followed up for 4 to 20 weeks, until they needed further treatment. They were assessed at baseline and weeks 2, 4, 8, 12, 16, and 20 after treatment. Dysport was significantly more efficacious than placebo at weeks 4, 8, and 12 as assessed by the Toronto Western Spasmodic Torticollis Rating Scale (10-point vs. 3.8-point reduction in total score, respectively, at week 4; P < or = 0.013). Of participants in the Dysport group, 38% showed positive treatment response, compared to 16% in the placebo group (95% confidence interval, 0.02-0.41). The median duration of response to Dysport was 18.5 weeks. Side effects were generally similar in the two treatment groups; only blurred vision and weakness occurred significantly more often with Dysport. No participants in the Dysport group converted from negative to positive antibodies after treatment. These results confirm previous reports that Dysport (500 units) is safe, effective, and well-tolerated in patients with cervical dystonia.

Epsilon-sarcoglycan mutations found in combination with other dystonia gene mutations.

Myoclonus-dystonia is a movement disorder associated with mutations in the epsilon-sarcoglycan gene (SGCE) in most families and in the DRD2 and DYT1 genes in two single families. In both of the latter families, we also found a mutation of SGCE. The molecular mechanisms through which the detected mutations may contribute to myoclonus-dystonia remain to be determined.

Parkinson's disease. Therapeutic strategies to improve patient function and quality of life.

Idiopathic Parkinson's disease (PD) is an age-related neuro-degenerative disorder characterized by slowness, stiffness, resting tremor, gait impairment, and postural instability. Levodopa is the most potent pharmacologic agent for symptom management and is associated with an increase in quality of life and longevity for patients with PD, but chronic use causes motor complications. The availability of several newer types of agents--dopamine agonists, monoamine oxidase inhibitors, and catechol-O-methyltransferase inhibitors--gives physicians increased flexibility with regard to first-line therapy, adjunct therapy, and managing or reducing the frequency of motor complications and other side effects associated with chronic levodopa therapy.