Congratulations on your new publication!
Congratulations to Drs. A. Enrique Martinez‐Nunez, Kelly Foote, Coralie DeHemptinne, Michael Okun and Joshua Wong on the publication of “Functional Connectivity to the Cerebellum and Resting‐State Networks Predict Earlier Improvement of Dystonia Following Globus Pallidus Internus‐Deep Brain Stimulation (GPi‐DBS),” which appears in the December issue of Movement Disorders.
Abstract
Background
Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is an established treatment for dystonia. However, the time from device activation to clinical improvement is typically prolonged, variable, and unpredictable. While most patients improve gradually over months, some show significant benefit within weeks. The neuroanatomical and network‐level mechanisms underlying early response remain unknown.
Objective
To investigate the structural and functional correlates of earlier symptom improvement in patients with isolated dystonia who responded to bilateral GPi‐DBS. Methods This retrospective study enrolled 46 patients. Early responders were defined as achieving ≥25% reduction in Unified Dystonia Rating Scale (UDRS) scores within 3 months post‐surgery. Preoperative magnetic resonance imaging (MRI) and postoperative computed tomography data were processed to localize electrodes, model volume of activated tissue, and calculate electric fields. Functional connectivity was assessed using normative resting‐state functional MRI (fMRI) data, while structural connectivity was estimated using fiber filtering of a histology‐based atlas.
Results
A stimulation ‘sweet spot’ at the ventral border of the lateral GPi and medial globus pallidus externus (GPe) was associated with early improvement. Early response correlated with neuromodulation of GPe‐subthalamic nucleus fibers and lenticular fasciculus. Stimulation sites connected to cerebellar cortex (lobules IX, crus I, crus II), default mode, and limbic networks were associated with earlier benefit.
Conclusions
These findings support a broader network model integrating cerebellum, limbic system, and basal ganglia in dystonia. Stimulation of cerebellar‐connected circuits may accelerate improvement independent of classical somatomotor networks. Results highlight novel targets and mechanisms for improving DBS effectiveness, suggesting multitarget, network‐informed strategies could enhance therapeutic outcomes.