Clinical Research Directory

VTS Sensorimotor Neuromodulation in WC

Writer's cramps (WC) is a focal task-specific upper limb dystonia that significantly impairs handwriting and other manual skills, affecting functionality. WC is one of the most common task-specific dystonias, affecting 3.8-80 per million individuals. The first-line management option is botulinum toxin injections in the muscles affected by the involuntary movements, causing a transient neuromuscular blocking effect and reducing muscle abnormal contraction. However, the effect lasts for around 3 months or less, is invasive, may cause unintended hand weakness, and the benefits are variable in terms of the severity of dystonic contraction and functional gain. Focal limb dystonia pathophysiology, including writer's cramps, has been linked to propriospinal signalling defects in the sensorimotor cortex modulation5, prompting an investigation into neuromodulation of this region as a modality for dystonia management. Other forms of dystonia have shown a reduction of the involuntary movements with vibrotactile stimulation (VTS), including cervical and laryngeal dystonia8. These results have supported the hypothesis that VTS alters the abnormal output of mechanical receptors from proprioceptive and tactile pathways to the sensorimotor cortex.Changes in neurophysiological markers of dystonia in the sensorimotor cortex also corroborated the modulatory effect. Furthermore, more invasive methods of neuromodulation, such as Globus Pallidus internus Deep Brain Stimulation, are known to be an effective treatment option for medically refractory dystonia, with evidence of promoting a similar result on the sensorimotor pathway via cortico-basal ganglia network direct stimulation. Finally, one of the most common ways of modulation is a core feature in dystonia, which is called an alleviating manoeuvre (AM) or geste antagoniste. This comprises a sensory or motor stimulation located in the anatomical area of the dystonia, which will transiently alleviate the involuntary movement. In that case, Functional MRI studies also suggest a sensorimotor network modulation in AM. Thus, there is considerable preliminary evidence to suggest the role of invasive and non-invasive neuromodulation in the treatment of dystonia. Given the variable and often suboptimal response to standard treatments for task-specific dystonia, such as WC, and the associated functional impairment, this study explores the role of vibrotactile stimulation (VTS) as a non-invasive neuromodulation tool for WC. VTS targets muscles involved in dystonic contractions, intending to create a non-invasive neuromodulation via propriospinal pathways to the sensorimotor cortex and improve motor control in individuals with WC. The effect described in previous studies lasts around 20-30 minutes, which should allow functionality for handwriting during that period of time. In the future, with the refinement of the technique's effectiveness, it could be escalated for a wearable treatment option. Based on the clinical and pathophysiological characteristics of task-specific dystonia it is reasonable to use a peripheral sensory modulation technique to try and reduced the abnormal motor cortical output this way reducing the dystonic movement. That has been proved successful in other types of dystonia. Thus, a pilot study for proof-of-concept concept and feasibility is a good first step towards that direction.

Attention and Eye Movement in Parkinson's Disease

The goal of this observational and interventional study is to understand how therapeutic deep brain stimulation (DBS) affects attention, perception and cognition in participants with Parkinson's disease (PD) and non-PD movement disorders, including essential tremor (ET) and dystonia (DT). The main questions it aims to answer are: * Does impaired control of attention and eye movement in PD alter how social cues are perceived and interpreted? * Does therapeutic DBS improve or worsen attentional and perceptual deficits for social cues in PD, ET and DT? * Can DBS be optimized to restore normal attentional control in PD while remaining an effective therapy for other aspects of the disorder. * What do parts of the brain targeted by DBS contribute to the control of attention? Using an eye tracking camera, investigators will study how participants with PD, ET and DT look at and perceive facial expressions of emotion before and after starting DBS therapy, in comparison to a group of healthy participants without ET, PD, DT or DBS. Participants with PD, ET and DT will see and rate morphed facial expressions on a computer screen in three conditions: * Before starting DBS therapy (over approximately 1 hour). * In the operating room, during the standard procedure to implant DBS electrodes, while the participant is awake (for no more than 15 minutes). * After starting DBS therapy, with brief experimental changes of DBS stimulation level and frequency (over approximately 1 hour).

Neurosurgical Outcome Network

The evaluation of neurosurgical outcomes varies from center to center, and the predictive factors that determine these outcomes are not fully known or shared. This study aims to assess outcomes and their predictors using measures agreed upon by the participating centers. Standardizing the evaluation of outcomes and predictors improves the quality of research, allows for data comparison, and facilitates a "common language" in routine clinical practice. Most importantly, it influences therapeutic decisions in various neurosurgical conditions. Clinically, the identified predictors can also be used during preoperative assessments to provide more precise guidance to patients undergoing surgery.