Challenges in Describing Tremor and Dystonia.

Tremor is defined as an oscillatory and rhythmical movement. By contrast, dystonia is defined by sustained or intermittent abnormal postures, repetitive movements, or both. Tremor and dystonia often coexist in the same individual.

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.

Evaluating Eye Tracking During Dichoptic Video Viewing With Varied Fellow Eye Contrasts in Amblyopia.

Purpose: This study uses eye tracking to investigate how varying fellow eye (FE) contrast during dichoptic video viewing influences eye movement patterns, and their associations with interocular suppression, visual acuity, and stereoacuity deficit in amblyopia.

Methods: Eye movements of 27 amblyopic and 8 healthy control participants were recorded during dichoptic viewing of stationary dots and videos with FE contrasts (100%, 50%, 25%, and 10%). Analysis included durations the amblyopic and FE spent in different stimulus regions, fixation switches, and eye deviation, and correlating these with suppression, visual acuity, and stereoacuity.

Assessing Changes in Motor Function and Mobility in Individuals with Parkinson's Disease After 12 Sessions of Patient-Specific Adaptive Dynamic Cycling.

Background And Purpose: This pilot randomized controlled trial evaluated the effects of 12 sessions of patient-specific adaptive dynamic cycling (PSADC) versus non-adaptive cycling (NA) on motor function and mobility in individuals with Parkinson's disease (PD), using inertial measurement unit (IMU) sensors for objective assessment.

Methods: Twenty-three participants with PD (13 in the PSADC group and 10 in the NA group) completed the study over a 4-week period. Motor function was measured using the Kinesia™ sensors and the MDS-UPDRS Motor III, while mobility was assessed with the TUG test using OPAL IMU sensors.

Utilizing Entropy of Cadence to Optimize Cycling Rehabilitation in Individuals With Parkinson's Disease.

Background: Previous studies have established that increased Sample Entropy (SampEn) of cadence, a measure of non-linear variability, during dynamic cycling leads to greater improvements in motor function for individuals with Parkinson's disease (PD). However, there is significant variability in responses among individuals with PD due to symptoms and disease progression.

Objectives: The aim of this study was to develop and test a paradigm for adapting a cycling exercise intervention using SampEn of cadence and rider effort to improve motor function.

Navigating Visual Challenges: How Parkinson's Disease Alters Cognitive Priorities in Visual Search.

Objective: Parkinson's disease (PD) hampers visual search tasks such as reading, driving, and navigation. We examined expectations from past experiences, guiding cognition and contextual priors, on visual search in PD.

Methods: We compared eye movements as PD and healthy participants searched for a hidden object (target) in cluttered real-world scenes.

Ion channel profiles of extraocular motoneurons and internuclear neurons in human abducens and trochlear nuclei.

Introduction: Extraocular muscles are innervated by two anatomically and histochemically distinct motoneuron populations: motoneurons of multiply-innervated fibers (MIF), and of singly-innervated fibers (SIF). Recently, it has been established by our research group that these motoneuron types of monkey abducens and trochlear nuclei express distinct ion channel profiles: SIF motoneurons, as well as abducens internuclear neurons (INT), express strong Kv1.1 and Kv3.

A 360° View for Large Language Models: Early Detection of Amblyopia in Children using Multi-View Eye Movement Recordings.

Amblyopia is a neurodevelopmental visual disorder that affects approximately 3-5% of children globally and it can lead to vision loss if it is not diagnosed and treated early. Traditional diagnostic methods, which rely on subjective assessments and expert interpretation of eye movement recordings presents challenges in resource-limited eye care centers. This study introduces a new approach that integrates the Gemini large language model (LLM) with eye-tracking data to develop a classification tool for diagnosis of patients with amblyopia.

Pallidal multifractal complexity is a new potential physiomarker of dystonia.

Objective: Low-frequency 4-12 Hz pallidal oscillations are being considered as potential physiomarkers for dystonia. We suggest investigating the multifractal properties of pallidal activity as an additional marker.

Methods: We employed local field potentials (LFP) recordings from 23 patients with dystonia who were undergoing deep brain stimulation (DBS) surgery to explore the connection between disease severity and the multifractal characteristics of pallidal activity.

Interdisciplinary insights into tremor in dystonia: Navigating clinical controversies, definitional challenges, and pathophysiological complexities.

This review delves into the historical evolution and ongoing controversy surrounding the relationship between tremor and dystonia. The Dystonia Consensus Panel and the International Parkinson's and Movement Disorders Society's Tremor Taskforce have attempted to define these entities, but the complexity arises when patients have a combination of both dystonia and tremor. The term "dystonic tremor" has sparked diverse interpretations, with debates over its clinical features and the need for more objectively defined characteristics.

Exploring Heading Direction Perception in Cervical Dystonia, Tremor, and Their Coexistence.

Objective: Dystonias, characterized by excessive muscle contractions resulting in involuntary postures and movements, impact 3 million people globally, making them the third most common movement disorder. Often accompanied by tremors, dystonias have epidemiological links and non-motor features shared with isolated tremor, such as essential tremor. Both dystonia and tremor present with balance dysfunction and abnormal involuntary movements, potentially linked to abnormal cerebellar function.

Improved Side-Effect Stimulation Thresholds and Postoperative Transient Confusion With Asleep, Image-Guided Deep Brain Stimulation.

Background And Objectives: Asleep, image-guided deep brain stimulation (DBS) is a modern alternative to awake, microelectrode recording (MER) guidance. Studies demonstrate comparable efficacy and complications between techniques, although some report lower stimulation thresholds for side effects with image guidance. In addition, few studies directly compare the risk of postoperative transient confusion (pTC) across techniques.

Objective assessment of eye alignment and disparity-driven vergence in Parkinson's disease.

Background: Self-reported diplopia is described in up to one-third of Parkinson's disease (PD) patients.

Objective: The purpose of our study was to expand our understanding of the mechanistic underpinnings of diplopia in PD. We hypothesize that the time-based control of eye alignment and increased eye deviation under binocular viewing will be related to the fusion-initiating and fusion-maintaining component deficits of disparity-driven vergence in PD.

Unraveling the Twist: Spatial Navigational Challenges in Cervical Dystonia.

Background: Cervical dystonia (CD) is an intricate neurological condition with motor and nonmotor symptoms. These include disruptions in visual perception, self-orientation, visual working memory, and vestibular functions. However, the specific impact of CD on perceiving self-motion direction, especially with isolated visual or vestibular stimuli, remains largely unexplored.

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.

Monitoring Eye Movement in Patients with Parkinson's Disease: What Can It Tell Us?

Parkinson's disease (PD) affects approximately 10 million individuals worldwide. Visual impairments are a common feature of PD. Patients report difficulties with visual scanning, impaired depth perception and spatial navigation, and blurry and double vision.

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.

Does Vestibular Motion Perception Correlate with Axonal Pathways Stimulated by Subthalamic Deep Brain Stimulation in Parkinson's Disease?

Perception of our linear motion - heading - is critical for postural control, gait, and locomotion, and it is impaired in Parkinson's disease (PD). Deep brain stimulation (DBS) has variable effects on vestibular heading perception, depending on the location of the electrodes within the subthalamic nucleus (STN). Here, we aimed to find the anatomical correlates of heading perception in PD.

DYT1 dystonia: Neurophysiological properties of the pallidal activity.

Objectives: The aim of this paper is to find the differences in the physiology of the pallidal neurons in DYT1 and non-DYT1 dystonia.

Methods: We performed microelectrode recording of the single unit activity in both segments of the globus pallidus during stereotactic implantation of electrodes for deep brain stimulation (DBS).

Results: We found a reduced firing rate, reduced burst rate, and increased pause index in both pallidal segments in DYT1.

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).