Fmri dystonia

BACKGROUND: Cervical dystonia (CD) is the most common form of focal dystonia with involuntary movements and postures of the head. The pathogenesis and neural mechanisms underlying CD have not been fully elucidated. METHODS: Twenty-seven newly drug-naïve patients with CD and 21 healthy controls (HCs) were recruited with clinical assessment and resting-state functional magnetic resonance imaging (rs-fMRI) scanning. Severity of CD was measured by Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and Tsui scores...

BACKGROUND: Writer's cramp (WC), a task specific form of dystonia, is considered to be a motor network disorder, but abnormal sensory tactile processing has also been acknowledged. The sensory spatial discrimination threshold (SDT) can be determined with a spatial acuity test (JVP domes). In addition to increased SDT, patients with WC exhibited dysfunctional sensory processing in the sensory cortex, insula, basal ganglia and cerebellum in a functional magnetic resonance imaging (fMRI) study while performing the spatial acuity test...

In cervical dystonia, functional MRI (fMRI) evidence indicates changes in several resting state networks, which revert in part following the botulinum neurotoxin A (BoNT) therapy. Recently, the involvement of the cerebellum in dystonia has gained attention. The aim of our study was to compare connectivity between cerebellar subdivisions and the rest of the brain before and after BoNT treatment. Seventeen patients with cervical dystonia indicated for treatment with BoNT were enrolled (14 female, aged 50.2 ± 8...

BACKGROUND: Although several brain networks play important roles in cervical dystonia (CD) patients, regional homogeneity (ReHo) changes in CD patients have not been clarified. We investigated to explore ReHo in CD patients at rest and analyzed its correlations with symptom severity as measured by Tsui scale. METHODS: A total of 19 CD patients and 21 gender-, age-, and education-matched healthy controls underwent fMRI scans at rest state. Data were analyzed by ReHo method...

Background: Primary blepharospasm (BSP) is one of the most common focal dystonia and its pathophysiological mechanism remains unclear. An unbiased method was used in patients with BSP at rest to observe voxel-wise brain-wide functional connectivity (FC) changes. Method: A total of 48 subjects, including 24 untreated patients with BSP and 24 healthy controls, were recruited to undergo functional magnetic resonance imaging (fMRI). The method of global-brain FC (GFC) was adopted to analyze the resting-state fMRI data...

BACKGROUND: The relationship between brain abnormalities and phenotypic characteristics in cervical dystonia (CD) patients has not been fully established, and little is known about the neuroplastic changes induced by botulinum toxin type-A (BoNT-A) treatment. METHODS: We retrospectively screened 92 CD patients presenting with rotational torticollis and 45 healthy controls from our database. After clinical assessment, 92 patients underwent baseline MRI scanning followed by a single-dose injection of BoNT-A...

Deep brain stimulation is an established therapy for multiple brain disorders, with rapidly expanding potential indications. Neuroimaging has advanced the field of deep brain stimulation through improvements in delineation of anatomy, and, more recently, application of brain connectomics. Older lesion-derived, localizationist theories of these conditions have evolved to newer, network-based "circuitopathies," aided by the ability to directly assess these brain circuits in vivo through the use of advanced neuroimaging techniques, such as diffusion tractography and fMRI...

A 29-year-old woman presented with head and neck dystonia, as well as functional seizures. The patient was an active military service member with a history of combat-related trauma. Resting blood oxygen level dependent (BOLD) functional MRI (fMRI) scans of the brain demonstrated an increased anterior cingulate component of the salience network and hyper-connectivity between the insula and cingulate. Following neurological and psychiatric evaluation, she was diagnosed with dissociative post-traumatic stress disorder, partially presenting as a functional movement disorder...

BACKGROUND: Reduced intracortical inhibition is a neurophysiologic finding in focal dystonia that suggests a broader problem of impaired cortical excitability within the brain. A robust understanding of the neurophysiology in dystonia is essential to elucidate the pathophysiology of the disorder and develop new treatments. The cortical silent period (cSP) is a reliable, non-invasive method to measure intracortical inhibition in the primary motor cortex associated with a muscle of interest...

Previous studies suggested that brain regions subtending affective-cognitive processes can be implicated in the pathophysiology of functional dystonia (FD). In this study, the role of the affective-cognitive network was explored in two phenotypes of FD: fixed (FixFD) and mobile dystonia (MobFD). We hypothesized that each of these phenotypes would show peculiar functional connectivity (FC) alterations in line with their divergent disease clinical expressions. Resting state fMRI (RS-fMRI) was obtained in 40 FD patients (12 FixFD; 28 MobFD) and 43 controls (14 young FixFD-age-matched [yHC]; 29 old MobFD-age-matched [oHC])...

BACKGROUND AND PURPOSE: Deep brain stimulation is a well-established treatment for generalized dystonia, but outcomes remain variable. Establishment of an imaging marker to guide device targeting and programming could possibly impact the efficacy of deep brain stimulation in dystonia, particularly in the absence of acute clinical markers to indicate benefit. We hypothesize that the stimulation-based functional and structural connectivity using resting-state fMRI and DTI can predict therapeutic outcomes in patients with generalized dystonia and deep brain stimulation...

Understanding the neuronal network dynamics underlying the third most common movement disorder, cervical dystonia, can be achieved using dynamic causal modelling. Current literature establishes structures of the midbrain network for covert attentional orienting as dysfunctional in patients with cervical dystonia. One of these structures is the superior colliculus, for which it is hypothesised that deficient GABAergic activity therein causes cervical dystonia. To understand the role that this node plays in cervical dystonia, various connectivity models of the midbrain network were compared under the influence of a loom-recede visual stimulus fMRI paradigm...

Cervical Dystonia (CD) is a neurological movement disorder characterized by intermittent muscle contractions in the head and neck. The pathophysiology and neural networks underpinning this condition are incompletely understood. There is increasing evidence that isolated focal dystonias are due to network-wide functional alterations. An abnormal temporal discrimination threshold (TDT) is believed to be a mediational endophenotype due to its prevalence in unaffected first-degree relatives as well as patients...

Sensory trick may relieve dystonic symptoms in patients with idiopathic cervical dystonia (CD). We investigated the patterns of brain functional MRI (fMRI) during resting state, sensory trick simulation and sensory trick imagination in CD patients both with and without an effective sensory trick. We recruited 17 CD patients and 15 healthy controls. Nine patients (CD-trick) had an effective sensory trick, while 8 patients (CD-no-trick) did not. Cervical range of motion validated instrument assessed dystonic posture and sensory trick effect...

Neuroimaging studies using functional magnetic resonance imaging (fMRI), which measures brain activity by detecting the changes in blood oxygenation levels, are advancing our understanding of the pathophysiology of dystonia. Neurobiological disturbances in dystonia, however, may affect neurovascular coupling and impact the interpretability of fMRI studies. We evaluated here whether the hemodynamic response patterns during a behaviorally matched motor task are altered in isolated cervical dystonia (CD). Twenty-five CD patients and 25 healthy controls (HCs) underwent fMRI scanning during a paced finger tapping task (nondystonic task in patients)...

A previously introduced Bayesian non-parametric multi-scale technique, called iterated Multigrid Priors (iMGP) method, is used to map the topographic organization of human primary somatosensory cortex (S1). We analyze high spatial resolution fMRI data acquired at ultra-high field (UHF, 7T) in individual subjects during vibrotactile stimulation applied to each distal phalange of the left hand digits using both a travelling-wave (TW) and event-related (ER) paradigm design. We compare the somatotopic digit representations generated in S1 using the iMGP method with those obtained using established fMRI paradigms and analysis techniques: Fourier-based analysis of travelling-wave data and General Linear Model (GLM) analysis of event-related data...

Background: Cervical dystonia (CD) is a neurological movement disorder characterized by involuntary head and neck movements and postures. Reports on microstructural and functional abnormalities in multiple brain regions not limited to the basal ganglia have been increasing in patients with CD. However, the neural bases of CD are unclear. This study is aimed at identifying cerebral functional abnormalities in CD by using resting-state functional magnetic resonance imaging (rs-fMRI). Methods: Using rs-fMRI data, voxel-mirrored homotopic connectivity (VMHC) and degree centrality were used to compare the alterations of the rs-functional connectivity (FC) between 19 patients with CD and 21 healthy controls...

OBJECTIVES: To determine the directionality of regional interactions and influences of one region on another within the functionally abnormal sensorimotor network in isolated focal dystonia. METHODS: A total of 40 patients with spasmodic dysphonia with and without dystonic tremor of voice and 35 healthy controls participated in the study. Independent component analysis (ICA) of resting-state fMRI was used to identify 4 abnormally coupled brain regions within the functional sensorimotor network in all patients compared to controls...

Background: An abnormal temporal discrimination threshold in cervical dystonia (CD) is considered to be a mediational endophenotype; in unaffected relatives it is hypothesized to indicate non-manifesting gene carriage. The pathogenesis underlying this condition remains unknown. Investigation of the neural networks involved in disordered temporal discrimination may highlight its pathomechanisms. Objective: To examine resting state brain function in unaffected relatives of CD patients with normal and abnormal temporal discrimination...

Botulinum toxin type A (BoNT) is considered an effective therapeutic option in cervical dystonia (CD). The pathophysiology of CD and other focal dystonias has not yet been fully explained. Results from neurophysiological and imaging studies suggest a significant involvement of the basal ganglia and thalamus, and functional abnormalities in premotor and primary sensorimotor cortical areas are considered a crucial factor in the development of focal dystonias. Twelve BoNT-naïve patients with CD were examined with functional MRI during a skilled hand motor task; the examination was repeated 4 weeks after the first BoNT injection to the dystonic neck muscles...