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Neurotoxicity Research Jan 2016The formation of neutralizing antibodies (NAbs) directed specifically against the active neurotoxin part of the botulinum neurotoxin (BoNT) complex is often cited as a... (Meta-Analysis)
Meta-Analysis Review
The formation of neutralizing antibodies (NAbs) directed specifically against the active neurotoxin part of the botulinum neurotoxin (BoNT) complex is often cited as a major cause of secondary non-responsiveness (SnR) to treatment. This systematic and meta-analytic review evaluates the frequency of NAbs among patients treated with BoNT therapy for any clinical indication. A comprehensive database search strategy was designed to retrieve relevant clinical data from the published literature up to April 2013. All English-language publications that analyzed NAbs prevalence in more than ten patients were included, regardless of BoNT formulation, assay method, and study design. For the meta-analysis, patients were divided into three categories: secondary nonresponse (SnR) patients, clinically responding patients and all patients, independently of BoNT responsiveness. The meta-analysis included 61 studies reporting data for 8525 patients; 4972 dystonic patients, 1170 patients with spasticity, 294 patients with urologic indications, 396 patient with hyperhidrosis, 1659 patients with glabellar line, and 34 patients with hypersalivation. Among the ‘‘all patients’’ group NAbs frequency was 20%for dystonia, 5.9%for spasticity, and 2.7% for urologic patients and 1.1% for other conditions. The prevalence of NAbs was lower (3.5%) among clinically responding patients and higher in 53.5%SnR patients. About a half of patients with SnR do not have NAbs. NAbs was high among patients treated with RIMA but it was not associated with clinical non-responsiveness. Meta-analysis of the frequency of NAbs and SnR are limited by the heterogeneity of study design and reported outcomes. Indeed the analysis of several factors that can influence the development of NAbs, i.e.,MHCof patients, frequency and site of injection, injection technique, cumulative dose, and toxin denaturation, was not specifically evaluated due to the paucity and heterogeneity of data. The identification of all these missing data should be taken into account in order to improve the methodology of future studies.
Topics: Animals; Antibodies, Neutralizing; Botulinum Toxins, Type A; Databases, Bibliographic; Humans; Nervous System Diseases; Neuromuscular Agents
PubMed: 26467676
DOI: 10.1007/s12640-015-9565-5 -
Frontiers in Neurology 2023The traditional approach to studying the neurobiological mechanisms of brain disorders and localizing brain function involves identifying brain abnormalities and...
BACKGROUND
The traditional approach to studying the neurobiological mechanisms of brain disorders and localizing brain function involves identifying brain abnormalities and comparing them to matched controls. This method has been instrumental in clinical neurology, providing insight into the functional roles of different brain regions. However, it becomes challenging when lesions in diverse regions produce similar symptoms. To address this, researchers have begun mapping brain lesions to functional or structural networks, a process known as lesion network mapping (LNM). This approach seeks to identify common brain circuits associated with lesions in various areas. In this review, we focus on recent studies that have utilized LNM to map neurological and psychiatric symptoms, shedding light on how this method enhances our understanding of brain network functions.
METHODS
We conducted a systematic search of four databases: PubMed, Scopus, and Web of Science, using the term "Lesion network mapping." Our focus was on observational studies that applied lesion network mapping in the context of neurological and psychiatric disorders.
RESULTS
Following our screening process, we included 52 studies, comprising a total of 6,814 subjects, in our systematic review. These studies, which utilized functional connectivity, revealed several regions and network overlaps across various movement and psychiatric disorders. For instance, the cerebellum was found to be part of a common network for conditions such as essential tremor relief, parkinsonism, Holmes tremor, freezing of gait, cervical dystonia, infantile spasms, and tics. Additionally, the thalamus was identified as part of a common network for essential tremor relief, Holmes tremor, and executive function deficits. The dorsal attention network was significantly associated with fall risk in elderly individuals and parkinsonism.
CONCLUSION
LNM has proven to be a powerful tool in localizing a broad range of neuropsychiatric, behavioral, and movement disorders. It holds promise in identifying new treatment targets through symptom mapping. Nonetheless, the validity of these approaches should be confirmed by more comprehensive prospective studies.
PubMed: 37456650
DOI: 10.3389/fneur.2023.1100067 -
Developmental Medicine and Child... Apr 2018To systematically review evidence for pharmacological/neurosurgical interventions for managing dystonia in individuals with cerebral palsy (CP) to inform a care pathway. (Review)
Review
AIM
To systematically review evidence for pharmacological/neurosurgical interventions for managing dystonia in individuals with cerebral palsy (CP) to inform a care pathway.
METHOD
Searches included studies with a minimum of five participants with dystonia in CP receiving oral baclofen, benzodiazepines (clonazepam, diazepam, lorazepam), clonidine, gabapentin, levodopa, trihexyphenidyl, botulinum toxin, intrathecal baclofen (ITB), or deep brain stimulation (DBS). Evidence was classified according to American Academy of Neurology guidelines.
RESULTS
Twenty-eight articles underwent data extraction: one levodopa, five trihexyphenidyl, three botulinum toxin, six ITB, and 13 DBS studies. No articles for oral baclofen, benzodiazepines, clonidine, or gabapentin met the inclusion criteria. Evidence for reducing dystonia was level C (possibly effective) for ITB and DBS; level C (possibly ineffective) for trihexyphenidyl; and level U (inadequate data) for botulinum toxin.
INTERPRETATION
For dystonia reduction, ITB and DBS are possibly effective, whereas trihexyphenidyl was possibly ineffective. There is insufficient evidence to support oral medications or botulinum toxin to reduce dystonia. There is insufficient evidence for pharmacological and neurosurgical interventions to improve motor function, decrease pain, and ease caregiving. The majority of the pharmacological and neurosurgical management of dystonia in CP is based on clinical expert opinion.
WHAT THIS PAPER ADDS
Intrathecal baclofen and deep brain stimulation are possibly effective in reducing dystonia. Current evidence does not support effectiveness of oral medications or botulinum toxin to reduce dystonia. Evidence is inadequate for pharmacological/neurosurgical interventions impact on improving motor function, pain/comfort, and easing caregiving. The majority of the care pathway rests on expert opinion.
Topics: Baclofen; Cerebral Palsy; Deep Brain Stimulation; Dystonia; Humans; Muscle Relaxants, Central; Neurosurgical Procedures
PubMed: 29405267
DOI: 10.1111/dmcn.13652 -
Journal of Neurology, Neurosurgery, and... Jul 2015Early aetiological diagnosis is of paramount importance for childhood dystonia because some of the possible underlying conditions are treatable. Numerous genetic and... (Review)
Review
Early aetiological diagnosis is of paramount importance for childhood dystonia because some of the possible underlying conditions are treatable. Numerous genetic and non-genetic causes have been reported, and diagnostic workup is often challenging, time consuming and costly. Recently, a paradigm shift has occurred in molecular genetic diagnostics, with next-generation sequencing techniques now allowing us to analyse hundreds of genes simultaneously. To ensure that patients benefit from these new techniques, adaptation of current diagnostic strategies is needed. On the basis of a systematic literature review of dystonia with onset in childhood or adolescence, we propose a novel diagnostic strategy with the aim of helping clinicians determine which patients may benefit by applying these new genetic techniques and which patients first require other investigations. We also provide an up-to-date list of candidate genes for a dystonia gene panel, based on a detailed literature search up to 20 October 2014. While new genetic techniques are certainly not a panacea, possible advantages of our proposed strategy include earlier diagnosis and avoidance of unnecessary investigations. It will therefore shorten the time of uncertainty for patients and their families awaiting a definite diagnosis.
Topics: Adolescent; Algorithms; Child; Decision Support Techniques; Diagnosis, Differential; Dystonia; Genetic Testing; Humans
PubMed: 25395479
DOI: 10.1136/jnnp-2014-309106 -
European Journal of Neurology Apr 2017The aim of this review was to provide strong clinical evidence of the efficacy of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in isolated... (Review)
Review
The aim of this review was to provide strong clinical evidence of the efficacy of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in isolated inherited or idiopathic dystonia. Eligible studies were identified after a systematic literature review of the effects of bilateral GPi-DBS in isolated dystonia. Absolute and percentage changes from baseline in the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) motor and disability scores were pooled, and associations between treatment effect and patient characteristics were explored using meta-regression. In total, 24 studies were included in the meta-analysis, comprising 523 patients. The mean absolute and percentage improvements in BFMDRS motor score at the last follow-up (mean 32.5 months; 24 studies) were 26.6 points [95% confidence interval (CI), 22.4-30.8] and 65.2% (95% CI, 59.6-70.7), respectively. The corresponding changes in disability score at the last follow-up (mean 32.9 months; 14 studies) were 6.4 points (95% CI, 5.0-7.8) and 58.6% (95% CI, 50.3-66.9). Multivariate meta-regression of absolute scores indicated that higher BFMDRS motor and disability scores before surgery, together with younger age at time of surgery, were the main factors associated with significantly better DBS outcomes at the latest follow-up. Reporting of safety data was frequently inconsistent and could not be included in the meta-analysis. In conclusion, patients with isolated inherited or idiopathic dystonia significantly improved after GPi-DBS. Better outcomes were associated with greater dystonia severity at baseline. These findings should be taken into consideration for improving patient selection for DBS.
Topics: Deep Brain Stimulation; Dystonia; Dystonic Disorders; Globus Pallidus; Humans; Treatment Outcome
PubMed: 28186378
DOI: 10.1111/ene.13255 -
Developmental Medicine and Child... Aug 2017To identify and systematically review the psychometric properties and clinical utility of dystonia and choreoathetosis scales reported for children with cerebral palsy... (Review)
Review
AIM
To identify and systematically review the psychometric properties and clinical utility of dystonia and choreoathetosis scales reported for children with cerebral palsy (CP).
METHOD
Six electronic databases were searched for dystonia and choreoathetosis scales with original psychometric data for children with CP aged 0 to 18 years.
RESULTS
Thirty-four papers met the inclusion criteria, which contained six scales purported to measure dystonia and/or choreoathetosis in children with CP: the Burke-Fahn-Marsden Dystonia Rating Scale; Barry-Albright Dystonia Scale; Unified Dystonia Rating Scale; Movement Disorder-Childhood Rating Scale; Movement Disorder-Childhood Rating Scale 0-3 Years; and the Dyskinesia Impairment Scale.
INTERPRETATION
Each scale provides useful information about dyskinesia, with most focusing on dystonia. The Barry-Albright Dystonia Scale, which was designed for CP, is the most commonly reported scale and least complex to use clinically. The Dyskinesia Impairment Scale is the only tool to consider both dystonia and choreoathetosis in CP. All tools are designed to classify movement disorders at the level of body functions and structures, rather than activity limitations or participation restrictions, although many provide some insight into the impact of dystonia on activities. Further studies are required to fully examine the validity, reliability, responsiveness, and clinical utility of each scale specifically for children with CP.
Topics: Adolescent; Athetosis; Cerebral Palsy; Child; Child, Preschool; Chorea; Dystonic Disorders; Humans; Infant; Severity of Illness Index
PubMed: 28485494
DOI: 10.1111/dmcn.13452 -
European Journal of Neurology Nov 2022Structural magnetic resonance techniques have been widely applied in neurological disorders to better understand tissue changes, probing characteristics such as volume,... (Review)
Review
BACKGROUND AND PURPOSE
Structural magnetic resonance techniques have been widely applied in neurological disorders to better understand tissue changes, probing characteristics such as volume, iron deposition and diffusion. Dystonia is a hyperkinetic movement disorder, resulting in abnormal postures and pain. Its pathophysiology is poorly understood, with normal routine clinical imaging in idiopathic forms. More advanced tools provide an opportunity to identify smaller scale structural changes which may underpin pathophysiology. This review aims to provide an overview of methodological approaches undertaken in structural brain imaging of dystonia cohorts, and to identify commonly identified pathways, networks or regions that are implicated in pathogenesis.
METHODS
Structural magnetic resonance imaging studies of idiopathic and genetic forms of dystonia were systematically reviewed. Adhering to strict inclusion and exclusion criteria, PubMed and Embase databases were searched up to January 2022, with studies reviewed for methodological quality and key findings.
RESULTS
Seventy-seven studies were included, involving 1945 participants. The majority of studies employed diffusion tensor imaging (DTI) (n = 45) or volumetric analyses (n = 37), with frequently implicated areas of abnormality in the brainstem, cerebellum, basal ganglia and sensorimotor cortex and their interconnecting white matter pathways. Genotypic and motor phenotypic variation emerged, for example fewer cerebello-thalamic tractography streamlines in genetic forms than idiopathic and higher grey matter volumes in task-specific than non-task-specific dystonias.
DISCUSSION
Work to date suggests microstructural brain changes in those diagnosed with dystonia, although the underlying nature of these changes remains undetermined. Employment of techniques such as multiple diffusion weightings or multi-exponential relaxometry has the potential to enhance understanding of these differences.
Topics: Brain; Diffusion Tensor Imaging; Dystonia; Dystonic Disorders; Humans; Iron; Magnetic Resonance Imaging
PubMed: 35785410
DOI: 10.1111/ene.15483 -
NeuroImage. Clinical 2023Hyperkinetic movement disorders (HMD) manifest as abnormal and uncontrollable movements. Despite reported involvement of several neural circuits, exact connectivity... (Review)
Review
BACKGROUND
Hyperkinetic movement disorders (HMD) manifest as abnormal and uncontrollable movements. Despite reported involvement of several neural circuits, exact connectivity profiles remain elusive.
OBJECTIVES
Providing a comprehensive literature review of resting-state brain connectivity alterations using resting-state fMRI (rs-fMRI). We additionally discuss alterations from the perspective of brain networks, as well as correlations between connectivity and clinical measures.
METHODS
A systematic review was performed according to PRISMA guidelines and searching PubMed until October 2022. Rs-fMRI studies addressing ataxia, chorea, dystonia, myoclonus, tics, tremor, and functional movement disorders (FMD) were included. The standardized mean difference was used to summarize findings per region in the Automated Anatomical Labeling atlas for each phenotype. Furthermore, the activation likelihood estimation meta-analytic method was used to analyze convergence of significant between-group differences per phenotype. Finally, we conducted hierarchical cluster analysis to provide additional insights into commonalities and differences across HMD phenotypes.
RESULTS
Most articles concerned tremor (51), followed by dystonia (46), tics (19), chorea (12), myoclonus (11), FMD (11), and ataxia (8). Altered resting-state connectivity was found in several brain regions: in ataxia mainly cerebellar areas; for chorea, the caudate nucleus; for dystonia, sensorimotor and basal ganglia regions; for myoclonus, the thalamus and cingulate cortex; in tics, the basal ganglia, cerebellum, insula, and frontal cortex; for tremor, the cerebello-thalamo-cortical circuit; finally, in FMD, frontal, parietal, and cerebellar regions. Both decreased and increased connectivity were found for all HMD. Significant spatial convergence was found for dystonia, FMD, myoclonus, and tremor. Correlations between clinical measures and resting-state connectivity were frequently described.
CONCLUSION
Key brain regions contributing to functional connectivity changes across HMD often overlap. Possible increases and decreases of functional connections of a specific region emphasize that HMD should be viewed as a network disorder. Despite the complex interplay of physiological and methodological factors, this review serves to gain insight in brain connectivity profiles across HMD phenotypes.
Topics: Humans; Tremor; Myoclonus; Tics; Dystonia; Magnetic Resonance Imaging; Chorea; Hyperkinesis; Brain; Brain Mapping; Dystonic Disorders; Ataxia; Neural Pathways
PubMed: 36669351
DOI: 10.1016/j.nicl.2022.103302 -
The European Journal of Neuroscience Feb 2021Transcranial magnetic stimulation (TMS) is a non-invasive method to assess neurophysiology of the primary motor cortex in humans. Dystonia is a poorly understood... (Meta-Analysis)
Meta-Analysis Review
Transcranial magnetic stimulation (TMS) is a non-invasive method to assess neurophysiology of the primary motor cortex in humans. Dystonia is a poorly understood neurological movement disorder, often presenting in an idiopathic, isolated form across different parts of the body. The neurophysiological profile of isolated dystonia compared to healthy adults remains unclear. We conducted a systematic review with meta-analysis of neurophysiologic TMS measures in people with isolated dystonia to provide a synthesized understanding of cortical neurophysiology associated with isolated dystonia. We performed a systematic database search and data were extracted independently by the two authors. Separate meta-analyses were performed for TMS measures of: motor threshold, corticomotor excitability, short interval intracortical inhibition, cortical silent period, intracortical facilitation and afferent-induced inhibition. Standardized mean differences were calculated using a random effects model to determine overall effect sizes and confidence intervals. Heterogeneity was explored using dystonia type subgroup analysis. The search resulted in 78 studies meeting inclusion criteria, of these 57 studies reported data in participants with focal hand dystonia, cervical dystonia, blepharospasm or spasmodic dysphonia, and were included in at least one meta-analysis. The cortical silent period, short-interval intracortical inhibition and afferent-induced inhibition was found to be reduced in isolated dystonia compared to controls. Reduced GABAergic-mediated inhibition in the primary motor cortex in idiopathic isolated dystonia's suggest interventions targeted to aberrant cortical disinhibition could provide a novel treatment. Future meta-analyses require neurophysiology studies to use homogeneous cohorts of isolated dystonia participants, publish raw data values, and record electromyographic responses from dystonic musculature where possible.
Topics: Adult; Dysphonia; Dystonic Disorders; Evoked Potentials, Motor; Humans; Motor Cortex; Neural Inhibition; Torticollis; Transcranial Magnetic Stimulation
PubMed: 32991762
DOI: 10.1111/ejn.14987 -
Movement Disorders Clinical Practice Oct 2022A systematic review of epidemiological studies of primary dystonia from 1985 and 2010 found an overall prevalence of 16.43 per 100,000 (95% CI = 12.09-22.32). (Review)
Review
BACKGROUND
A systematic review of epidemiological studies of primary dystonia from 1985 and 2010 found an overall prevalence of 16.43 per 100,000 (95% CI = 12.09-22.32).
METHODS
We performed a systematic review of studies from 2010 and 2022 to determine if there are important differences in epidemiology between these time periods.
RESULTS
Nineteen studies were included. Incidence of cervical dystonia, blepharospasm, and oromandibular dystonia were each reported in one study; one study reported incidence for all adult onset idiopathic focal dystonias combined. Using data from 11 studies, we performed random effects meta-analyses of the prevalence of cervical dystonia (9.95 per 100,000; 95% CI = 3.51-28.17), blepharospasm (2.82 per 100,000; 95% CI = 1.12-7.12), laryngeal dystonia (0.40 per 100,000; 95% CI = 0.09-1.83), upper limb dystonia (1.27 per 100,000; 95% CI = 0.36-4.52), oromandibular dystonia (0.57 per 100,000; 95% CI = 0.15-2.15), and idiopathic or inherited isolated dystonia all subtypes combined (30.85 per 100,000; 95% CI = 5.06-187.74). All studies reported more cases of dystonia in females. There was no significant difference in prevalence by subgroup analysis based on time of study publication (1985-2010 vs. 2010-2022). Subgroup analysis of differences in prevalence by dystonia subtype by continent using all studies published (1985-2022) revealed significant regional differences in the prevalence of cervical and laryngeal dystonia.
CONCLUSION
The incidence and prevalence of idiopathic or inherited isolated dystonia in the last decade was not significantly different from earlier reports. Population-based studies across multiple geographic areas are needed to obtain a clearer understanding of the epidemiology of this condition.
PubMed: 36247920
DOI: 10.1002/mdc3.13524