Unraveling the neural signatures: Distinct pallidal patterns in dystonia subtypes.

Introduction: Dystonia manifests as slow twisting movements (pure dystonia) or repetitive, jerky motions (jerky dystonia). Dystonia can coexist with myoclonus (myoclonus dystonia) or tremor (tremor dystonia). Each of these presentations can have distinct etiology, can involve discrete sensorimotor networks, and may have characteristic neurophysiological signature.

External Factors Modulating Pain and Pain-Related Functional Impairment in Cervical Dystonia.

Background: Little is known about factors modulating pain and pain-related functional impairment in isolated cervical dystonia (CD).

Objective: The aim was to assess the prevalence and interrelationship between pain-modulating factors and pain-related determinants of functional impairment and quality of life in CD.

Methods: We analyzed pain-aggravating and pain-relieving external factors, the degree of pain-related functional impact on routine activities, and the relationship between these and pain severity, using cross-sectional data collected using the Pain in Dystonia Scale (PIDS) from 85 participants with CD.

Ultrastructural analysis of nigrostriatal dopaminergic terminals in a knockin mouse model of DYT1 dystonia.

DYT1 dystonia is associated with decreased striatal dopamine release. In this study, we examined the possibility that ultrastructural changes of nigrostriatal dopamine terminals could contribute to this neurochemical imbalance using a serial block face/scanning electron microscope (SBF/SEM) and three-dimensional reconstruction to analyse striatal tyrosine hydroxylase-immunoreactive (TH-IR) terminals and their synapses in a DYT1(ΔE) knockin (DYT1-KI) mouse model of DYT1 dystonia. Furthermore, to study possible changes in vesicle packaging capacity of dopamine, we used transmission electron microscopy to assess the synaptic vesicle size in striatal dopamine terminals.

Inosine monophosphate dehydrogenase intranuclear inclusions are markers of aging and neuronal stress in the human substantia nigra.

We explored mechanisms involved in the age-dependent degeneration of human substantia nigra (SN) dopamine (DA) neurons. Owing to its important metabolic functions in post-mitotic neurons, we investigated the developmental and age-associated changes in the purine biosynthetic enzyme inosine monophosphate dehydrogenase (IMPDH). Tissue microarrays prepared from post-mortem samples of SN from 85 neurologically intact participants humans spanning the age spectrum were immunostained for IMPDH combined with other proteins.

Demographics and Clinical Characteristics Associated with the Spread of New-Onset Laryngeal Dystonia.

Objectives: Adult-onset idiopathic laryngeal dystonia (LD) can be associated with the risk of spread to muscles in the body. Subjects with extralaryngeal onset of dystonia have exhibited spread to the larynx. Previous studies analyze the spread of other dystonias but emphasis has not been placed on LD.

Proprioceptive Modulation of Pallidal Physiology in Cervical Dystonia.

Background: There is a growing body of evidence suggesting that botulinum toxin can alter proprioceptive feedback and modulate the muscle-spindle output for the treatment of dystonia. However, the mechanism for this modulation remains unclear.

Methods: We conducted a study involving 17 patients with cervical dystonia (CD), seven of whom had prominent CD and 10 with generalized dystonia (GD) along with CD.

Does Pallidal Physiology Determine the Success of Unilateral Deep Brain Stimulation in Cervical Dystonia?

Pallidal deep brain stimulation is a well-known surgical treatment for cervical dystonia. The resolution of dystonia typically requires bilateral pallidal stimulation, but in some instances, unilateral stimulation has been successful. In such instances, generally, the stimulated hemisphere was contralateral to the dystonic sternocleidomastoid, but rarely it was ipsilateral.

Pain Reduction in Cervical Dystonia Following Treatment with IncobotulinumtoxinA: A Pooled Analysis.

This analysis pooled pain severity data from four phase 3 and 4 studies of incobotulinumtoxinA (incoBoNT-A) for the treatment of cervical dystonia (CD) in adults. CD-related pain severity was assessed at baseline, each injection visit, and 4 weeks after each injection of incoBoNT-A using the Toronto Western Spasmodic Torticollis Rating Scale pain severity subscale or a pain visual analog scale. Both were analyzed using a score range of 0-10 and pain was categorized as mild, moderate, or severe.

The Pain in Dystonia Scale (PIDS)-Development and Validation in Cervical Dystonia.

Background: A better understanding of pain in adult-onset idiopathic dystonia (AOID) is needed to implement effective therapeutic strategies.

Objective: To develop a new rating instrument for pain in AOID and validate it in cervical dystonia (CD).

Methods: Development and validation of the Pain in Dystonia Scale (PIDS) comprised three phases.

Effects of neck proprioceptive modulation on pallidal network connectivity in dystonia.

Cervical dystonia (CD) is the third most common movement disorder affecting 1 million people worldwide. Proprioceptive modulation is the hallmark of contemporary therapies for dystonia, but the mechanism for this intervention is unclear. We studied proprioceptive influence on CD by measuring the spontaneous single-neuron responses and local field potentials (LFP) from the globus pallidus interna (GPi) in 17 CD patients (9 isolated CD and 8 with CD as a feature of generalized dystonia).

Isolated Cervical Dystonia: Diagnosis and Classification.

This document presents a consensus on the diagnosis and classification of isolated cervical dystonia (iCD) with a review of proposed terminology. The International Parkinson and Movement Disorder Society Dystonia Study Group convened a panel of experts to review the main clinical and diagnostic issues related to iCD and to arrive at a consensus on diagnostic criteria and classification. These criteria are intended for use in clinical research, but also may be used to guide clinical practice.

What Is Hemidystonia?

Background: Hemidystonia is defined as dystonia restricted to one side of the body. It is traditionally believed to result from a lesion in the contralateral hemisphere.

Objectives: To describe a series of hemidystonia patients without lesions on brain imaging.

Validation of a guideline to reduce variability in diagnosing cervical dystonia.

Background: Cervical dystonia is characterized by a variable pattern of neck muscle involvement. Due to the lack of a diagnostic test, cervical dystonia diagnosis is based on clinical examination and is therefore subjective. The present work was designed to provide practical guidance for clinicians in confirming or refuting suspected cervical dystonia.

Motor and psychiatric features in idiopathic blepharospasm: A data-driven cluster analysis.

Introduction: Idiopathic blepharospasm is a clinically heterogeneous dystonia also characterized by non motor symptoms.

Methods: We used a k-means cluster analysis to assess 188 patients with idiopathic blepharospasm in order to identify relatively homogeneous subpopulations of patients, using a set of motor and psychiatric variables to generate the cluster solution.

Results: Blepharospasm patients reached higher scores on scales assessing depressive- and anxiety-related disorders than healthy/disease controls.

Measurement Properties of Clinical Scales Rating the Severity of Blepharospasm: A Multicenter Observational Study.

Background: Several scales have been proposed to clinically evaluate the Motor Severity of Blepharospasm (BSP) but information about their measurement properties as a multicenter instrument is limited.

Objective: To compare the measurement properties of four clinical scales in rating the severity of BSP in a large sample of patients from multiple sites.

Methods: The Burke-Fahn-Marsden Scale (BFMS), the Global Dystonia Severity Rating Scale (GDRS), the Jankovic Rating Scale (JRS), and the Blepharospasm Severity Rating Scale (BSRS) were administered to 211 patients across 10 sites who were also requested to self-complete the Blepharospasm Disability Index (BDI).

Clinical and Structural Findings in Patients With Lesion-Induced Dystonia: Descriptive and Quantitative Analysis of Published Cases.

Background And Objectives: Brain lesions are a well-recognized etiology of dystonia. These cases are especially valuable because they offer causal insight into the neuroanatomical substrates of dystonia. To date, knowledge of lesion-induced dystonia comes mainly from isolated case reports or small case series, restricting broader description and analysis.

The apparent paradox of phenotypic diversity and shared mechanisms across dystonia syndromes.

Purpose Of Review: We describe here how such mechanisms shared by different genetic forms can give rise to motor performance dysfunctions with a clinical aspect of dystonia.

Recent Findings: The continuing discoveries of genetic causes for dystonia syndromes are transforming our view of these disorders. They share unexpectedly common underlying mechanisms, including dysregulation in neurotransmitter signaling, gene transcription, and quality control machinery.