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The characterization of neural signatures within the somatosensory pathway is essential for elucidating the pathogenic mechanisms of central post-stroke pain (CPSP) and developing more effective treatments such as deep brain stimulation (DBS). We explored the characteristics of thalamic neural oscillations in response to varying pain levels under multi-day local field potential (LFP) recordings and examined the influences of continuous DBS on these thalamic activities. We recorded LFPs from the left ventral posterolateral thalamus (VPL) of a patient with CPSP in the resting state under both off- and on-stimulation conditions. We observed significant differences in the power spectral density (PSD) of different pain levels in the delta, theta and gamma frequency bands of the left VPL; 75Hz DBS significantly increased the PSD of delta and decreased the PSD of low-beta, while 130Hz DBS significantly reduced the PSD of theta and low-beta. Thalamic stimulation modulated the neural oscillations related to pain, and the changes in neural activities in response to stimulation could serve as quantitative indicators for pain relief.

Introduction: Deep brain stimulation (DBS) of subthalamic nucleus (STN) has been well-established and increasingly applied in patients with isolated dystonia. Nevertheless, the surgical efficacy varies among patients. This study aims to explore the factors affecting clinical outcomes of STN-DBS on isolated dystonia and establish a well-performed prediction model. Methods: In this prospective study, thirty-two dystonia patients were recruited and received bilateral STN-DBS at our center. Their baseline characteristics and up to one-year follow-up outcomes were assessed. Implanted electrodes of each subject were reconstructed with their contact coordinates and activated volumes calculated. We explored correlations between distinct clinical characteristics and surgical efficacy. Those features were then trained for the model in outcome prediction via support vector regression (SVR) algorithm and testified through cross-validation. Results: Patients demonstrated an average clinical improvement of 56 ± 25 % after STN-DBS, significantly affected by distinct symptom forms and activated volumes. The optimal targets and activated volumes were concentratedly located at the dorsal posterior region to STN. Most patients had a rapid response to STN-DBS, and their motor score improvement within one week was highly associated with long-term outcomes. The trained SVR model, contributed by distinct weights of features, could reach a maximum prediction accuracy with mean errors of 11 ± 7 %. Conclusion: STN-DBS demonstrated significant and rapid therapeutic effects in patients with isolated dystonia, by possibly affecting the pallidofugal fibers. Early improvement highly indicates the ultimate outcomes. SVR proves valid in outcome prediction. Patients with predominant phasic and generalized symptoms, shorter disease duration, and younger onset age may be more favorable to STN-DBS in the long run.

Background: Psychiatric comorbidities are common in Parkinson's disease (PD) and may change with high-frequency stimulation targeting the subthalamic nucleus. Numerous accounts indicate subthalamic alpha-frequency oscillation is implicated in emotional processing. While intermittent alpha-frequency (10Hz) stimulation induces positive emotional effects, with more ventromedial contacts inducing larger effects, little is known about the subacute effect of ventral 10Hz subthalamic stimulation on emotional processing. Objective/Hypothesis: To evaluate the subacute effect of 10Hz stimulation at bilateral ventral subthalamic nucleus on emotional processing in PD patients using an affective task, compared to that of clinical-frequency stimulation and off-stimulation. Methods: Twenty PD patients with bilateral subthalamic deep brain stimulation for more than six months were tested with the affective task under three stimulation conditions (10Hz, 130Hz, and off-stimulation) in a double-blinded randomized design. Results: While 130Hz stimulation reduced arousal ratings in all patients, 10Hz stimulation increased arousal selectively in patients with higher depression scores. Furthermore, 10Hz stimulation induced a positive shift in valence rating to negative emotional stimuli in patients with lower apathy scores, and 130Hz stimulation led to more positive valence to emotional stimuli in the patients with higher apathy scores. Notably, we found correlational relationships between stimulation site and affective rating: arousal ratings increase with stimulation from anterior to posterior site, and positive valence ratings increase with stimulation from dorsal to ventral site of the ventral subthalamic nucleus. Conclusions: Our findings highlight the distinctive role of 10Hz stimulation on subjective emotional experience and unveil the spatial organization of the stimulation effect.

The subthalamic nucleus (STN) and globus pallidus internus (GPi) are the two most common and effective target brain areas for deep brain stimulation (DBS) treatment of advanced Parkinson's disease. Although DBS has been shown to restore functional neural circuits of this disorder, the changes in topological organization associated with active DBS of each target remain unknown. To investigate this, we acquired resting-state functional magnetic resonance imaging (fMRI) data from 34 medication-free patients with Parkinson's disease that had DBS electrodes implanted in either the subthalamic nucleus or internal globus pallidus (n = 17 each), in both ON and OFF DBS states. Sixteen age-matched healthy individuals were used as a control group. We evaluated the regional information processing capacity and transmission efficiency of brain networks with and without stimulation, and recorded how stimulation restructured the brain network topology of patients with Parkinson's disease. For both targets, the variation of local efficiency in motor brain regions was significantly correlated (p < 0.05) with improvement rate of the Uniform Parkinson's Disease Rating Scale-III scores, with comparable improvements in motor function for the two targets. However, non-motor brain regions showed changes in topological organization during active stimulation that were target-specific. Namely, targeting the STN decreased the information transmission of association, limbic and paralimbic regions, including the inferior frontal gyrus angle, insula, temporal pole, superior occipital gyri, and posterior cingulate, as evidenced by the simultaneous decrease of clustering coefficient and local efficiency. GPi-DBS had a similar effect on the caudate and lenticular nuclei, but enhanced information transmission in the cingulate gyrus. These effects were not present in the DBS-OFF state for GPi-DBS, but persisted for STN-DBS. Our results demonstrate that DBS to the STN and GPi induce distinct brain network topology reconstruction patterns, providing innovative theoretical evidence for deciphering the mechanism through which DBS affects disparate targets in the human brain.

Background: Given that anorexia nervosa (AN) is a life-threatening mental disorder and has poor clinical outcomes, novel effective treatments are warranted, especially for severe and persistent cases. Objective: To investigate the safety, feasibility, and clinical outcomes of using deep brain stimulation (DBS) of the nucleus accumbens (NAcc) in treatment-refractory AN patients. Methods: A total of 28 women with refractory AN underwent NAcc-DBS and completed this 2-year follow-up study. The clinical outcomes, including body mass index (BMI) and mood, anxiety, and obsessive symptoms, were assessed using a series of psychiatric scales at 6 and 24 months post operation. Results: While no fatalities were reported during this study, 1 patient showed device rejection. The most common short-term side effect observed was varying degrees of pain at the incision sites (n = 22), which usually disappeared 3–4 days following the operation. No severe surgical adverse events were observed. Compared to presurgical levels, significant increases in BMI and improvement in psychiatric scale scores were noted during the 6-month follow-up and were maintained at the 2-year review. Finally, a post-hoc analysis revealed that the NAcc-DBS was less effective for weight restoration in patients with the binge-eating/purge subtype of AN than in those with the restricting subtype (R-AN). Conclusion: Our long-term follow-up study suggests that NAcc-DBS is safe and effective for improving the BMI and psychiatric symptoms of patients with refractory AN. Although NAcc-DBS appears to be more suitable for patients with R-AN, strict inclusion criteria must be applied considering surgery-related complications.

In this retrospective study, by assuming that the therapeutic impedances were equal to 1 kΩ, we found that the mechanism by which deep brain stimulation of the subthalamic nucleus (STN) changed the motor laterality in Parkinson's disease (PD) may not be related to the difference in weighted average of the total electrical energy delivered to each side of STN.

Parkinson's disease (PD) is a movement disorder caused by dopaminergic neurodegeneration. Levodopa (L-dopa) is an effective medication for alleviating motor symptoms in PD that has been shown previously to reduce subcortical beta (13–30 Hz) oscillations. How L-dopa influences oscillations in the motor cortex is unclear. In this study, 21 PD patients were recorded with magnetoencephalography (MEG) in L-dopa ON and OFF states. Oscillatory components of resting-state power spectra were compared between the two states and the significant effect was localized using beamforming. Unified Parkinson's Disease Rating Scale (UPDRS) III akinesia and rigidity sub-scores for the most affected hemibody were correlated with source power values for the contralateral hemisphere. An L-dopa-induced power increase was found over the central sensors significant in the 18–30 Hz range (F(1,20) > 14.8, PFWE corr

Introduction: Some patients with advanced Parkinson's disease (PD) develop refractory axial symptoms and motor complications following initially effective subthalamic nucleus (STN) deep brain stimulation (DBS). We aim to determine whether globus pallidus internus (GPi) stimulation can improve refractory axial symptoms and dyskinesia, as well as psychosocial functioning and quality of life, in this group of patients who no longer benefit from STN DBS. Methods: In this pilot study, bilateral pallidal stimulation treatment was given to 7 patients with advanced PD who had developed refractory axial symptoms, including speech and swallowing difficulties, and painful dyskinesia, after long-term (>5 y) subthalamic stimulation. The follow-up period was 6 months. Primary clinical outcome measures focused on motor symptom severity, motor complications, psychosocial function, and quality of life. Secondary outcome measures included daily dose of antiparkinsonian medication and patient's body weight. Results: After pallidal stimulation, patients showed an overall 44% improvement in motor symptom scores at 6-month follow-up along with a 49% improvement in dyskinesia, a 33% improvement in psychosocial functioning, and a 42% improvement in quality of life. No adverse events occurred during the study. Conclusions: These initial results indicate that bilateral GPi DBS could provide significant clinical benefits to patients whose axial symptoms cannot or can no longer be controlled by STN DBS. Keywords: Parkinson's disease, Deep brain stimulation, Globus pallidus internus, Subthalamic nucleus