Deep Brain Stimulation Therapy Research Articles

E.3 fMRI correlates of symptom-specific improvement in STN deep brain stimulation

Background: Subthalamic nucleus (STN) deep brain stimulation (DBS) improves the cardinal symptoms of Parkinson’s disease (PD). However, the therapeutic mechanisms are incompletely understood. By leveraging patient-specific brain responses to DBS using functional magnetic resonance imaging (fMRI) acquired during stimulation, we identify and validate symptom-specific networks associated with clinical improvement. Methods: Forty PD patients with STN-DBS were enrolled for fMRI using a 30-sec DBS-ON/OFF cycling paradigm. The four cardinal motor outcomes of PD were chosen a priori and measured using the Movement Disorder Society-Sponsored Revision of the Unified Parkinson’s Disease Rating Scale, part III (MDS-UPDRSIII): axial instability, tremor, rigidity, bradykinesia. Stimulation-dependent changes in blood oxygen level-dependent (BOLD) signal were correlated with each symptom. Results: The relationship between BOLD response and outcomes revealed significant networks of clinical response (p<0.001). Using BOLD responses from the network hubs, each symptom-specific model was significantly predictive of actual improvement: axial instability (R2=0.38, p=0.000026), bradykinesia (R2=0.29, p=0.00033), rigidity (R2=0.40, p=0.000013), tremor (R2=0.26, p=0.00073). Conclusions: Using patient-specific imaging, we provide evidence of an association between DBS-evoked fMRI response and individual symptom improvement. Brain networks associated with clinical improvement were different depending on the PD symptom examined, suggesting the presence of symptom-specific networks of efficacy which may allow personalization of DBS therapy.

Protocol for combined N-of-1 trials to assess cerebellar neurostimulation for movement disorders in children and young adults with dyskinetic cerebral palsy.

Movement and tone disorders in children and young adults with cerebral palsy are a great source of disability. Deep brain stimulation (DBS) of basal ganglia targets has a major role in the treatment of isolated dystonias, but its efficacy in dyskinetic cerebral palsy (DCP) is lower, due to structural basal ganglia and thalamic damage and lack of improvement of comorbid choreoathetosis and spasticity. The cerebellum is an attractive target for DBS in DCP since it is frequently spared from hypoxic ischemic damage, it has a significant role in dystonia network models, and small studies have shown promise of dentate stimulation in improving CP-related movement and tone disorders. Ten children and young adults with DCP and disabling movement disorders with or without spasticity will undergo bilateral DBS in the dorsal dentate nucleus, with the most distal contact ending in the superior cerebellar peduncle. We will implant Medtronic Percept, a bidirectional neurostimulator that can sense and store brain activity and deliver DBS therapy. The efficacy of cerebellar DBS in improving quality of life and motor outcomes will be tested by a series of N-of-1 clinical trials. Each N-of-1 trial will consist of three blocks, each consisting of one month of effective stimulation and one month of sham stimulation in a random order with weekly motor and quality of life scales as primary and secondary outcomes. In addition, we will characterize abnormal patterns of cerebellar oscillatory activity measured by local field potentials from the intracranial electrodes related to clinical assessments and wearable monitors. Pre- and 12-month postoperative volumetric structural and functional MRI and diffusion tensor imaging will be used to identify candidate imaging markers of baseline disease severity and response to DBS. Our goal is to test a cerebellar neuromodulation therapy that produces meaningful changes in function and well-being for people with CP, obtain a mechanistic understanding of the underlying brain network disorder, and identify physiological and imaging-based predictors of outcomes useful in planning further studies. ClinicalTrials.gov NCT06122675, first registered November 7, 2023.

The utility of PET imaging in depression.

This educational review article aims to discuss growing evidence from PET studies in the diagnosis and treatment of depression. PET has been used in depression to explore the neurotransmitters involved, the alterations in neuroreceptors, non-neuroreceptor targets (e.g., microglia and astrocytes), the severity and duration of the disease, the pharmacodynamics of various antidepressants, and neurobiological mechanisms of non-pharmacological therapies like psychotherapy, electroconvulsive therapy, and deep brain stimulation therapy, by showing changes in brain metabolism and receptor and non-receptor targets. Studies have revealed alterations in neurotransmitter systems such as serotonin, dopamine, GABA, and glutamate, which are linked to the pathophysiology of depression. Overall, PET imaging has furthered the neurobiological understanding of depression. Despite these advancements, PET findings have not yet led to significant changes in evidence-based practices. Addressing the reasons behind inconsistencies in PET imaging results, conducting large sample size studies with a more standardized methodological approach, and investigating further the genetic and neurobiological aspects of depression may better leverage PET imaging in future studies.

The role of the nucleus basalis of Meynert in neuromodulation therapy: a systematic review from the perspective of neural network oscillations.

As a crucial component of the cerebral cholinergic system and the Papez circuit in the basal forebrain, dysfunction of the nucleus basalis of Meynert (NBM) is associated with various neurodegenerative disorders. However, no drugs, including existing cholinesterase inhibitors, have been shown to reverse this dysfunction. Due to advancements in neuromodulation technology, researchers are exploring the use of deep brain stimulation (DBS) therapy targeting the NBM (NBM-DBS) to treat mental and neurological disorders as well as the related mechanisms. Herein, we provided an update on the research progress on cognition-related neural network oscillations and complex anatomical and projective relationships between the NBM and other cognitive structures and circuits. Furthermore, we reviewed previous animal studies of NBM lesions, NBM-DBS models, and clinical case studies to summarize the important functions of the NBM in neuromodulation. In addition to elucidating the mechanism of the NBM neural network, future research should focus on to other types of neurons in the NBM, despite the fact that cholinergic neurons are still the key target for cell type-specific activation by DBS.

Fundamentals of deep brain stimulation for Parkinson's disease in clinical practice: part 1.

Deep brain stimulation (DBS) is recognized as an established therapy for Parkinson's disease (PD) and other movement disorders in the light of the developments seen over the past three decades. Long-term efficacy is established for PD with documented improvement in the cardinal motor symptoms of PD and levodopa-induced complications, such as motor fluctuations and dyskinesias. Timing of patient selection is crucial to obtain optimal benefits from DBS therapy, before PD complications become irreversible. The objective of this first part review is to examine the fundamental concepts of DBS for PD in clinical practice, discussing the historical aspects, patient selection, potential effects of DBS on motor and non-motor symptoms, and the practical management of patients after surgery.

480 Effect of Chronic DBS on Ventral Capsule Ventral Striatum-Specific Circadian Rhythm in Refractory Obsessive-Compulsive Disorder

INTRODUCTION: Deep brain stimulation (DBS) of the ventral capsule/ventral striatum (VC/VS) improves symptoms in ∼66% of patients with treatment-resistant obsessive-compulsive disorder (OCD). However, a common adverse effect of VC/VS DBS is hypomania, marked by decreased need for sleep and increased risk-taking behaviors. Modern DBS devices have enabled 24-hour collection of neural data, allowing for tracking of circadian rhythms reflected by VC/VS local field potentials (LFPs). METHODS: We implanted six patients with treatment-resistant OCD with a DBS device configured for constant VC/VS stimulation and recording. Spectral power in the 9 ± 2.5 Hz band was estimated onboard the device every 10 minutes for a median of 249 days (range 77-608). We assessed the rhythmicity of power in this spectral band by fitting 7-day retrospective rolling windows of per-day normalized LFP power to cosine functions using least-squared regression. Output metrics included acrophase (time of peak activity), amplitude, and fit significance. We quantified trends in acrophase over time using Pearson correlation. RESULTS: All six patients demonstrated consistent 24-hour cyclic LFP activity bilaterally. Two of the six had diurnal peaks which shifted significantly earlier across the study period. The remaining four patients had nocturnal peaks, all shifting significantly later over time. Notably, a patient in the latter group experienced three days of hypomania after DBS initiation associated with circadian disruptions even after clinical symptom resolution. Only after clinical DBS adjustment 2 weeks later did circadian rhythm rapidly return to pre-hypomanic levels. CONCLUSIONS: Study patients demonstrated evolving circadian VC/VS LFP activity across the course of DBS therapy, usually independent of cyclic whole-brain activity (i.e. sleep). Conversely, disruptions to these circadian patterns, as observed here during hypomania, may serve as biomarkers of region-specific stimulation side effects.

Insertional effect following electrode implantation: an underreported but important phenomenon.

Deep brain stimulation has revolutionized the treatment of movement disorders and is gaining momentum in the treatment of several other neuropsychiatric disorders. In almost all applications of this therapy, the insertion of electrodes into the target has been shown to induce some degree of clinical improvement prior to stimulation onset. Disregarding this phenomenon, commonly referred to as 'insertional effect', can lead to biased results in clinical trials, as patients receiving sham stimulation may still experience some degree of symptom amelioration. Similar to the clinical scenario, an improvement in behavioural performance following electrode implantation has also been reported in preclinical models. From a neurohistopathologic perspective, the insertion of electrodes into the brain causes an initial trauma and inflammatory response, the activation of astrocytes, a focal release of gliotransmitters, the hyperexcitability of neurons in the vicinity of the implants, as well as neuroplastic and circuitry changes at a distance from the target. Taken together, it would appear that electrode insertion is not an inert process, but rather triggers a cascade of biological processes, and, as such, should be considered alongside the active delivery of stimulation as an active part of the deep brain stimulation therapy.

Levodopa-Carbidopa-Entacapone Intestinal Gel in Advanced Parkinson Disease: A Multicenter Real-Life Experience.

For Parkinson disease (PD) patients who have been diagnosed with advanced disease that can no longer be effectively controlled with optimized oral or transdermal medications, a range of device-aided therapies (DAT) are available, comprising either deep brain stimulation or infusion therapies providing continuous dopaminergic stimulation. Levodopa-entacapone-carbidopa intestinal gel (LECIG) infusion is the latest DAT for advanced PD (APD) that was approved in Romania in 2021. What is the experience to date in real-world clinical practice in Romania regarding the efficacy and tolerability of LECIG in APD? A retrospective evaluation of 74 APD patients treated with LECIG at 12 specialized APD centers in Romania. Demographic data and various clinical parameters were recorded, including Mini Mental State Evaluation score or Montreal Cognitive Assessment Test score. Levodopa-equivalent daily dose and the administered doses of levodopa and other PD medications were evaluated at baseline and after starting LECIG treatment. The efficacy of LECIG in reducing daily hours of off time, motor fluctuations, and dyskinesias were assessed. Any percutaneous endoscopic gastrojejunostomy system or device complications after starting LECIG treatment were noted. At baseline, patients were taking oral levodopa for a mean of 5.3 times per day, with a high proportion also taking concomitant add-on therapies (dopamine agonists, 86%, monoamine oxidase type-B inhibitors, 53%; catechol-O-methyltransferase inhibitors, 64%). LECIG treatment significantly reduced daily off time versus baseline from 5.7 h/d to 1.7 hours per day ( P < 0.01). Duration and severity of dyskinesias was also significantly reduced versus baseline, and improvements were observed in Hoehn and Yahr Scale scores. LECIG treatment also allowed a significant reduction in the use of concomitant oral medications. These findings suggest that LECIG treatment is an effective DAT option in APD that can simplify the treatment regimen.

Management of essential tremor deep brain stimulation-induced side effects.

Deep brain stimulation (DBS) is an effective surgical therapy for carefully selected patients with medication refractory essential tremor (ET). The most popular anatomical targets for ET DBS are the ventral intermedius nucleus (VIM) of the thalamus, the caudal zona incerta (cZI) and the posterior subthalamic area (PSA). Despite extensive knowledge in DBS programming for tremor suppression, it is not uncommon to experience stimulation induced side effects related to DBS therapy. Dysarthria, dysphagia, ataxia, and gait impairment are common stimulation induced side effects from modulation of brain tissue that surround the target of interest. In this review, we explore current evidence about the etiology of stimulation induced side effects in ET DBS and provide several evidence-based strategies to troubleshoot, reprogram and retain tremor suppression.

DiMANI: diffusion MRI for anatomical nuclei imaging-Application for the direct visualization of thalamic subnuclei.

The thalamus is a centrally located and heterogeneous brain structure that plays a critical role in various sensory, motor, and cognitive processes. However, visualizing the individual subnuclei of the thalamus using conventional MRI techniques is challenging. This difficulty has posed obstacles in targeting specific subnuclei for clinical interventions such as deep brain stimulation (DBS). In this paper, we present DiMANI, a novel method for directly visualizing the thalamic subnuclei using diffusion MRI (dMRI). The DiMANI contrast is computed by averaging, voxelwise, diffusion-weighted volumes enabling the direct distinction of thalamic subnuclei in individuals. We evaluated the reproducibility of DiMANI through multiple approaches. First, we utilized a unique dataset comprising 8 scans of a single participant collected over a 3-year period. Secondly, we quantitatively assessed manual segmentations of thalamic subnuclei for both intra-rater and inter-rater reliability. Thirdly, we qualitatively correlated DiMANI imaging data from several patients with Essential Tremor with the localization of implanted DBS electrodes and clinical observations. Lastly, we demonstrated that DiMANI can provide similar features at 3T and 7T MRI, using varying numbers of diffusion directions. Our results establish that DiMANI is a reproducible and clinically relevant method to directly visualize thalamic subnuclei. This has significant implications for the development of new DBS targets and the optimization of DBS therapy.

Directional deep brain stimulation in the management of Parkinson's disease: efficacy and constraints-an analytical appraisal.

Deep brain stimulation (DBS) is a widely employed treatment for Parkinson's disease. However, conventional DBS utilizing ring-shaped leads can often result in undesirable side effects by stimulating nearby brain structures, thus limiting its effectiveness. To address this issue, a novel DBS electrode was developed to allow for directional stimulation, avoiding neighboring structures. This literature review aims to analyze the disparities between conventional and directional DBS and discuss the benefits and limitations associated with this innovative electrode design, focusing on the stimulation-induced side effects it can or cannot mitigate. A comprehensive search was conducted in MEDLINE/PubMed, ScienceDirect, and EBSCO databases using the Boolean search criteria: "Deep brain stimulation" AND "Parkinson" AND "Directional." Following the application of inclusion and exclusion criteria, the selected articles were downloaded for full-text reading. Subsequently, the results were organized and analyzed to compose this article. Numerous studies have demonstrated that directional DBS effectively reduces side effects associated with brain stimulation, prevents the stimulation of non-targeted structures, and expands the therapeutic window, among other advantages. However, it has been observed that directional DBS may be more challenging to program and requires higher energy consumption. Furthermore, there is a lack of standardization among different manufacturers of directional DBS electrodes. Various stimulation-induced side effects, including dysarthria, dyskinesia, paresthesias, and symptoms of pyramidal tract activation, have been shown to be mitigated with the use of directional DBS. Moreover, directional electrodes offer a wider therapeutic window and a reduced incidence of undesired effects, requiring the same or lower minimum current for symptom relief compared to conventional DBS. The utilization of directional leads in DBS offers numerous advantages over conventional electrodes without significant drawbacks for patients undergoing directional DBS therapy.

Effect of deep brain stimulation compared with drug therapy alone on the progression of Parkinson's disease.

Parkinson's disease (PD) symptoms deteriorate with disease progression. Although deep brain stimulation (DBS) can effectively improve the motor signs of PD patients, it is not yet known whether DBS surgery, which is an invasive treatment modality, may change the progression of PD. The aim of this work was to compare the effect of DBS with that of drug treatment on the progression of PD. A total of 77 patients with PD with the Hoehn and Yahr scale (HY) stage of 2.5 or 3 were included, and were divided into 34 in the drug therapy alone group (Drug-G) and 43 in the DBS therapy group (DBS-G). All patients were subjected to a follow-up of 2 years, and disease severity was assessed by the Unified Parkinson's Disease Rating Scale part III (UPDRS-III), the Montreal Cognitive Assessment (MOCA), the Hamilton Anxiety Scale (HAMA), and the Hamilton Depression Scale (HAMD) scores. In addition, the quality of life of patients and the burden on their family were assessed by the 39-item PD questionnaire (PDQ-39) scores, daily levodopa equivalent dose (LED), patient's annual treatment-related costs, and the Zarit Caregiver Burden Scale (ZCBS) score. The changes in relevant scale scores between the two groups were compared at each follow-up stage. The UPDRS-III score of the patients in the "off" state increased from year to year in both groups, and the degree of increase of this score was greater in the DBS-G than in the Drug-G group. The MOCA score in both groups began to decline in the 2nd year of follow-up, and the decline was greater in the Drug-G than in the DBS-G group. DBS treatment did not affect patients' psychiatric disorders. The PDQ39, LED, costs, and ZCBS were negatively correlated with the follow-up time in patients in the DBS-G group, and positively correlated with the follow-up time in patients in the Drug-G. PD is progressive regardless of treatment. The findings from this follow-up study suggest that the disease progression of patients in DBS-G may be slightly faster compared to the drug-G, but the advantages of DBS are also evident. Indeed, DBS better improves patient's motor signs and quality of life and reduces the family burden. In addition, DBS has less impact on patients in terms of cognitive and mental effects.

Double dissociation of dopamine and subthalamic nucleus stimulation on effortful cost/benefit decision making

Deep brain stimulation (DBS) and dopaminergic therapy (DA) are common interventions for Parkinson's disease (PD). Both treatments typically improve patient outcomes, and both can have adverse side effects on decision making (e.g., impulsivity).1,2 Nevertheless, they are thought to act via different mechanisms within basal ganglia circuits.3 Here, we developed and formally evaluated their dissociable predictions within a single cost/benefit effort-based decision-making task. In the same patients, we manipulated DA medication status and subthalamic nucleus (STN) DBS status within and across sessions. Using a series of descriptive and computational modeling analyses of participant choices and their dynamics, we confirm a double dissociation: DA medication asymmetrically altered participants' sensitivities to benefits vs. effort costs of alternative choices (boosting the sensitivity to benefits while simultaneously lowering sensitivity to costs); whereas STN DBS lowered the decision threshold of such choices. To our knowledge, this is the first study to show, using a common modeling framework, a dissociation of DA and DBS within the same participants. As such, this work offers a comprehensive account for how different mechanisms impact decision making, and how impulsive behavior (present in DA-treated patients with PD and DBS patients) may emerge from separate physiological mechanisms.

Case report: Lingual dystonia symptoms treated with botulinum toxin in patients with THAP1 mutation

Background: THAP1 mutation dystonia is a known genetic cause of generalized dystonia. THAP1 mutation frequently presents with clinical features of bulbar dysfunction, including oromandibular and lingual dystonia. Patients complain of significant speech, chewing, and swallowing difficulties leading to major occupational and social disabilities. While bilateral globus pallidus internus deep brain stimulation (DBS) is powerful therapy for generalized dystonia and improves dystonia symptoms in the cervical and limb region, it may not improve speech despite multiple adjustments to the stimulation parameters. Treating lingual dystonia symptoms with oral medications is commonly unsatisfactory. Botulinum toxin injection, a potent therapy for focal forms of dystonia is currently underutilized in clinical practice for treating lingual dystonia.Cases: We present two patients with THAP1 mutation reporting lingual dystonia symptoms. The first patient did not meet the eligibility criteria for DBS therapy due to significant psychiatric symptoms. The second patient received DBS with improvements in cervical, limb, and trunk symptoms but complained of severe speech difficulties that did not improve despite multiple programming sessions. These patients were treated with botulinum toxin injections every 12 weeks for more than 3 years, with speech improvements lasting most of the cycle. For the most part they tolerated botulinum toxin without bothersome side effects. Along with the clinical histories, we present objective perceptual analysis of speech samples collected before and after botulinum toxin injections in one of the treatment cycles.Conclusion: Botulinum toxin injections that are clinically beneficial for mitigating lingual dystonia symptoms should be utilized to address symptoms of THAP1 mutation dystonia that may not be amenable to other therapies, such as the DBS.

Brain Temporal-Spectral Functional Variability Reveals Neural Improvements of DBS Treatment for Disorders of Consciousness.

Deep brain stimulation (DBS) is establishing itself as a promising treatment for disorders of consciousness (DOC). Measuring consciousness changes is crucial in the optimization of DBS therapy for DOC patients. However, conventional measures use subjective metrics that limit the investigations of treatment-induced neural improvements. The focus of this study is to analyze the regulatory effects of DBS and explain the regulatory mechanism at the brain functional level for DOC patients. Specifically, this paper proposed a dynamic brain temporal-spectral analysis method to quantify DBS-induced brain functional variations in DOC patients. Functional near-infrared spectroscopy (fNIRS) that promised to evaluate consciousness levels was used to monitor brain variations of DOC patients. Specifically, a fNIRS-based experimental procedure with auditory stimuli was developed, and the brain activities during the procedure from thirteen DOC patients before and after the DBS treatment were recorded. Then, dynamic brain functional networks were formulated with a sliding-window correlation analysis of phase lag index. Afterwards, with respect to the temporal variations of global and regional networks, the variability of global efficiency, local efficiency, and clustering coefficient were extracted. Further, dynamic networks were converted into spectral representations by graph Fourier transform, and graph energy and diversity were formulated to assess the spectral global and regional variability. The results showed that DOC patients under DBS treatment exhibited increased global and regional functional variability that was significantly associated with consciousness improvements. Moreover, the functional variability in the right brain regions had a stronger correlation with consciousness enhancements than that in the left brain regions. Therefore, the proposed method well signifies DBS-induced brain functional variations in DOC patients, and the functional variability may serve as promising biomarkers for consciousness evaluations in DOC patients.

Neurosurgical precision at its peak: deep brain stimulation - patient selection strategy and surgical technique – a video article

Deep Brain Stimulation (DBS) has emerged as a promising therapeutic approach for various neurological disorders. This video article elucidates the intricacies of DBS surgery and patient selection criteria. The article comprehensively discusses the indications for DBS across diverse conditions including Parkinson’s disease, primary generalized dystonia, essential tremor, obsessive-compulsive disorder, Tourette’s syndrome, drug-resistant major depression, drug-resistant epilepsy, minimally conscious state, and certain addictive disorders. The article ensure optimal outcomes and patient safety. The surgical procedure is meticulously detailed, encompassing the pre-operative planning phase involving Magnetic Resonance Imaging (MRI) and stereotactic coordinates determination. The step-by-step surgical process is elucidated, from frame application and Computed Tomography (CT) fusion to electrode implantation and confirmation of placement. Post-operative management, including programming of the Implantable Pulse Generator (IPG) and addressing complications, is also discussed. By providing insights into the surgical nuances of DBS and patient selection criteria, this video article serves as a valuable resource for neurosurgeons and healthcare professionals involved in the management of neurological disorders amenable to DBS therapy.

Weight loss in Parkinson's disease: A retrospective comparison between oral medication and device–assisted therapies

ObjectiveWeight loss (WL) is the most common symptom among patients with Parkinson's disease (PD) and has been reported to start several years before the diagnosis of PD. The relationship between WL and PD treatment is complex. This study aimed to characterize the impact of PD treatment on WL and find clues to establish the administration of nutrition for patients with PD. Materials and methodsEighty-two patients with PD (mean age, 58.4 ± 10.2 years; mean Hoehn and Yahr stage, 3.2 ± 0.7) were recruited. Their treatments included deep brain stimulation (DBS) therapy (n = 34), levodopa/carbidopa intestinal gel (LCIG) therapy (n = 13), and oral medication alone (n = 35). Based on the medical records, the age of onset, disease duration, treatment options, videofluoroscopic dysphagia scale, blood test results, and weight change were collected. ResultsThe median WL per year and rate of WL were −1.0 ± 2.8 kg and −1.9 ± 4.7 %, respectively. Most patients (93 %) were classified into normal nutrition and mild malnutrition groups by their CONUT scores. The median WL of the DBS group was significantly lower than that of the oral medication alone group (p < 0.01). The rate of WL showed a significant negative correlation with the age of onset (rho = −0.328, p = 0.003), but showed a significant positive correlation with the disease duration (rho = 0.231, p = 0.04). ConclusionThese results highlighted WL in the early stages of PD and suggested the need for adequate monitoring for patients undergoing device-aided therapy as well as oral medicine-treated patients with greater WL.

Pacemaker, organ or walking stick? Pre-op association with and post-op subjective perception of a deep brain stimulation device

This study was conducted in a pre-post design with a survey of patients who had undergone deep brain stimulation (DBS) as treatment for a neurological movement disorder. The aim of the study was to compare patients' expectations and beliefs before a DBS intervention with patients' subjective experience of this intervention. The longitudinal study of patients (n=132) with an indication for DBS therapy was based on a written survey at the time points of preoperative screening (pre-op) and one-year follow-up (post-op). Preoperatively, a clear majority of respondents believed DSB to be similar to a pacemaker intervention, but one year after the intervention less than one third did so, as they compared DBS to using a walking stick or glasses. The experience of DBS in the patient's own body seems to be comparable by means of individually different associations, whereby the comparison with non-invasive aids predominates postoperatively. The discussion of these descriptions in the educational interview can contribute to a realistic horizon of patients' expectations before DBS.

Impact of deep brain stimulation therapy on the vertebral sagittal balance in Parkinson’s disease patients

Impact of deep brain stimulation therapy on the vertebral sagittal balance in Parkinson’s disease patients

BGRL: Basal Ganglia inspired Reinforcement Learning based framework for deep brain stimulators

Deep Brain Stimulation (DBS) is an implantable medical device used for electrical stimulation to treat neurological disorders. Traditional DBS devices provide fixed frequency pulses, but personalized adjustment of stimulation parameters is crucial for optimal treatment. This paper introduces a Basal Ganglia inspired Reinforcement Learning (BGRL) approach, incorporating a closed-loop feedback mechanism to suppress neural synchrony during neurological fluctuations. The BGRL approach leverages the resemblance between the Basal Ganglia region of brain by incorporating the actor–critic architecture of reinforcement learning (RL). Simulation results demonstrate that BGRL significantly reduces synchronous electrical pulses compared to other standard RL algorithms. BGRL algorithm outperforms existing RL methods in terms of suppression capability and energy consumption, validated through comparisons using ensemble oscillators. Results shown in the paper demonstrate BGRL suppressed the synchronous electrical pulses across three signaling regimes namely regular, chaotic and bursting by 40%, 146% and 40% respectively as compared to soft actor–critic model. BGRL shows promise in effectively suppressing neural synchrony in DBS therapy, providing an efficient alternative to open-loop methodologies.