Abnormal Connectivity of the Head Neural Integrator in Cervical Dystonia.

Background: Cervical dystonia is characterized by abnormal neck and head movements, possibly related to a dysfunction of the interstitial nucleus of Cajal (INC) and the head neural integrator, a system responsible for the control of head and eye movements. However, neuroanatomical evidence of alterations in the head neural integrator in cervical dystonia is sparse.

Objectives: We investigated structural and functional integrity of the INC and its connections in cervical dystonia.

Quantitative tremor monitoring before, during and after MR-guided focused ultrasound thalamotomy for essential tremor with MR compatible accelerometers.

Background: MR-guided focused ultrasound (MRgFUS) has been developed to treat essential tremor effectively and noninvasively. Currently, clinical examination is used to identify therapeutic efficacy during treatment, but MRgFUS surgery could benefit from real-time, rater-independent quantitative monitoring of tremor, such as accelerometry data.

Methods: Fourteen patients with medically refractory essential tremor underwent MRgFUS thalamotomy.

Age-Trajectories of Higher-Order Diffusion Properties of Major Brain Metabolites in Cerebral and Cerebellar Gray Matter Using In Vivo Diffusion-Weighted MR Spectroscopy at 3T.

Healthy brain aging involves changes in both brain structure and function, including alterations in cellular composition and microstructure across brain regions. Unlike diffusion-weighted MRI (dMRI), diffusion-weighted MR spectroscopy (dMRS) can assess cell-type specific microstructural changes, providing indirect information on both cell composition and microstructure through the quantification and interpretation of metabolites' diffusion properties. This work investigates age-related changes in the higher-order diffusion properties of total N-Acetyl-aspartate (neuronal biomarker), total choline (glial biomarker), and total creatine (both neuronal and glial biomarker) beyond the classical apparent diffusion coefficient in cerebral and cerebellar gray matter of healthy human brain.

Resting-State Cortico-Cerebellar Connectivity Correlates with Post-Stroke Motor Recovery - A Prospective Functional MRI Study.

Cerebellar functional and structural connectivity are likely related to motor function after stroke. Less is known about motor recovery, which is defined as a gain of function between two time points, and about the involvement of the cerebellum. Fifteen patients who were hospitalized between 2018 and 2020 for a first cerebral ischemic event with persistent upper limb deficits were assessed by resting-state functional MRI (rsfMRI) and clinical motor score measurements at 3, 9 and 15 weeks after stroke.

Psychiatric phenotype in neurodevelopmental myoclonus-dystonia is underpinned by abnormality of cerebellar modulation on the cerebral cortex.

Psychiatric symptoms are common in neurodevelopmental movement disorders, including some types of dystonia. However, research has mainly focused on motor manifestations and underlying circuits. Myoclonus-dystonia is a rare and homogeneous neurodevelopmental condition serving as an illustrative paradigm of childhood-onset dystonias, associated with psychiatric symptoms.

Brain modulation after exergaming training in advanced forms of Parkinson's disease: a randomized controlled study.

Background: Physical activity combined with virtual reality and exergaming has emerged as a new technique to improve engagement and provide clinical benefit for gait and balance disorders in people with Parkinson's disease (PD).

Objective: To investigate the effects of a training protocol using a home-based exergaming system on brain volume and resting-state functional connectivity (rs-FC) in persons with PD.

Methods: A single blind randomized controlled trial was conducted in people with PD with gait and/or balance disorders.

Sustained reduction of essential tremor with low-power non-thermal transcranial focused ultrasound stimulations in humans.

Background: Transcranial ultrasound stimulation (TUS) is a non-invasive brain stimulation technique; when skull aberrations are compensated for, this technique allows, with millimetric accuracy, circumvention of the invasive surgical procedure associated with deep brain stimulation (DBS) and the limited spatial specificity of transcranial magnetic stimulation.

Objective: /hypothesis: We hypothesize that MR-guided low-power TUS can induce a sustained decrease of tremor power in patients suffering from medically refractive essential tremor.

Methods: The dominant hand only was targeted, and two anatomical sites were sonicated in this exploratory study: the ventral intermediate nucleus of the thalamus (VIM) and the dentato-rubro-thalamic tract (DRT).

High-density transcranial direct current stimulation to improve upper limb motor function following stroke: study protocol for a double-blind randomized clinical trial targeting prefrontal and/or cerebellar cognitive contributions to voluntary motion.

Background: Focal brain lesions following a stroke of the middle cerebral artery induce large-scale network disarray with a potential to impact multiple cognitive and behavioral domains. Over the last 20 years, non-invasive brain neuromodulation via electrical (tCS) stimulation has shown promise to modulate motor deficits and contribute to recovery. However, weak, inconsistent, or at times heterogeneous outcomes using these techniques have also highlighted the need for novel strategies and the assessment of their efficacy in ad hoc controlled clinical trials.

Non-Motor Symptoms and Quality of Life in Patients with PRRT2-Related Paroxysmal Kinesigenic Dyskinesia.

Background: Monoallelic pathogenic variants of often result in paroxysmal kinesigenic dyskinesia (PKD). Little is known about health-related quality of life (HrQoL), non-motor manifestations, self-esteem, and stigma in patients with PKD.

Objectives: We investigated non-motor symptoms and how they related to HrQoL in a genetically homogeneous group of -PKD patients.

Can neuroscience enlighten the philosophical debate about free will?

Free will has been at the heart of philosophical and scientific discussions for many years. However, recent advances in neuroscience have been perceived as a threat to the commonsense notion of free will as they challenge two core requirements for actions to be free. The first is the notion of determinism and free will, i.

Brain dysfunction in gait disorders of Caribbean atypical Parkinsonism and progressive supranuclear palsy patients: A comparative study.

Introduction: Gait disorders and falls occur early in progressive supranuclear palsy (PSP-RS) and Caribbean atypical parkinsonism (Caribbean AP). However, the link between these signs and brain lesions has never been explored in these patient populations. Here, we investigate and compare the imaging factors that relate to gait and balance disorders in Caribbean AP and PSP-RS patients.

Fixel-Based Analysis Reveals Whole-Brain White Matter Abnormalities in Cervical Dystonia.

Background: Cervical dystonia (CD) is a form of isolated focal dystonia typically associated to abnormal head, neck, and shoulder movements and postures. The complexity of the clinical presentation limits the investigation of its pathophysiological mechanisms, and the neural networks associated to specific motor manifestations are still the object of debate.

Objectives: We investigated the morphometric properties of white matter fibers in CD and explored the networks associated with motor symptoms, while regressing out nonmotor scores.

Developmental coordination disorder subtypes in children: An unsupervised clustering.

Aim: To identify subtypes of developmental coordination disorder (DCD) in children.

Method: Children with DCD diagnosed through comprehensive evaluation at Robert-Debré Children's University Hospital (Paris, France) were consecutively enrolled from February 2017 to March 2020. We performed an unsupervised hierarchical clustering based on principal component analysis using a large set of variables encompassing cognitive, motor, and visuospatial scores (Wechsler Intelligence Scale for Children, Fifth Edition; Developmental Neuropsychological Assessment, Second Edition; Movement Assessment Battery for Children, Second Edition).

Cerebellar and basal ganglia structural connections in humans: Effect of aging and relation with memory and learning.

Introduction: The cerebellum and basal ganglia were initially considered anatomically distinct regions, each connected thalamic relays which project to the same cerebral cortical targets, such as the motor cortex. In the last two decades, transneuronal viral transport studies in non-human primates showed bidirectional connections between the cerebellum and basal ganglia at the subcortical level, without involving the cerebral cortical motor areas. These findings have significant implications for our understanding of neurodevelopmental and neurodegenerative diseases.

Cerebello-thalamic activity drives an abnormal motor network into dystonic tremor.

Dystonic tremor syndromes are highly burdensome and treatment is often inadequate. This is partly due to poor understanding of the underlying pathophysiology. Several lines of research suggest involvement of the cerebello-thalamo-cortical circuit and the basal ganglia in dystonic tremor syndromes, but their role is unclear.

Somatotopy of cervical dystonia in motor-cerebellar networks: Evidence from resting state fMRI.

Introduction: Cervical dystonia is the most frequent form of isolated focal dystonia. It is often associated with a dysfunction in brain networks, mostly affecting the basal ganglia, the cerebellum, and the somatosensory cortex. However, it is unclear if such a dysfunction is somato-specific to the brain areas containing the representation of the affected body part, and may thereby account for the focal expression of cervical dystonia.

Identification of a Brain Network Underlying the Execution of Freely Chosen Movements.

Action selection refers to the decision regarding which action to perform in order to reach a desired goal, that is, the "what" component of intention. Whether the action is freely chosen or externally instructed involves different brain networks during the selection phase, but it is assumed that the way an action is selected should not influence the subsequent execution phase of the same movement. Here, we aim to test this hypothesis by investigating whether the modality of movement selection influences the brain networks involved during the execution phase of the movement.

Loss of floor plate Netrin-1 impairs midline crossing of corticospinal axons and leads to mirror movements.

In humans, execution of unimanual movements requires lateralized activation of the primary motor cortex, which then transmits the motor command to the contralateral hand through the crossed corticospinal tract (CST). Mutations in NTN1 alter motor control lateralization, leading to congenital mirror movements. To address the role of midline Netrin-1 on CST development and subsequent motor control, we analyze the morphological and functional consequences of floor plate Netrin-1 depletion in conditional knockout mice.