Outcome Of Deep Brain Stimulation Research Articles

Translational evaluation of metabolic risk factors impacting DBS efficacy for PD-Related sleep and depressive disorders: preclinical, prospective and cohort studies.

Parkinson's disease (PD) is linked with metabolic risk factors including body mass index (BMI), fasting blood glucose (FBG), cholesterol levels, and triglycerides (TG). The extent to which these factors affect motor symptoms, depression, and sleep problems in PD, as well as their role in determining the success of deep brain stimulation (DBS) therapy, is yet to be fully understood. This study delved into the effects of metabolic risk factors like BMI, FBG, cholesterol, and TG on the outcomes of DBS in treating PD-related depression and sleep disturbances, across both mouse models and human subjects. DBS showcased noticeable betterment in depression and sleep perturbations in both PD-afflicted mice and patients. High-sugar-high-fat diet aggravates MPTP-induced depression and sleep disorders in mice. PD-afflicted individuals presenting with depressive and sleep disorders demonstrated elevated metrics of BMI, FBG, blood cholesterol, and TG. Remarkably, these metrics bore considerable adverse influences on the efficiency of DBS in ameliorating depression and sleep issues, yet spared motor symptoms. The favorable impacts of DBS persisted for approximately 6 years, post which a significant decline was noted. Importantly, our translational evidence from both murine controls and patient cohorts indicated that antihyperglycemic and antihyperlipidemic therapies bolstered the efficacy of DBS in mitigating PD-related depression and sleep disturbances, without impinging upon motor functions in patients. In summary, this research emphasizes that DBS is a powerful treatment option for depression and sleep issues in PD, with its success influenced by metabolic risk factors. It further suggests that incorporating treatments for high blood sugar and cholesterol can enhance the efficacy of DBS in treating depression and sleep disturbances in PD, without impacting motor symptoms, highlighting the importance of metabolic risk management in PD patients receiving DBS.

Cost-Effectiveness Analysis of Deep Brain Stimulation for the Treatment of Alcohol Use Disorder and Alcoholic Liver Disease.

Alcohol use disorder (AUD) is a major public health concern and cause of mortality and morbidity. Alcohol-associated liver disease (ALD) is a debilitating complication of AUD, mitigated by abstinence from alcohol use. Deep brain stimulation (DBS) is emerging as a potential treatment for AUD. However, its cost-effectiveness compared to the standard medical treatment is unclear. To estimate the cost-effectiveness of DBS compared to medical management for patients with AUD and ALD. We utilized a decision analytic model based on published literature to conduct a cost-effectiveness analysis of costs and health outcomes for DBS and medical management in patients with AUD and ALD. We also carried out a threshold analysis to determine the probability of success necessary for DBS to be cost-effective. Costs were measured in 2024 US dollars and effectiveness in quality-adjusted life years (QALYs). We used a time horizon of 1-2 years and adopted a societal perspective. Our results show that for AUD patients in general, DBS is not cost-effective at any DBS success rate. However, for advanced ALD patients, defined as fibrosis stage 3 or beyond DBS becomes cost-effective. For these patients, DBS is cost-effective over a two-year period at a $100,000 willingness-to-pay threshold at DBS success rates greater than 53%. For advanced decompensated ALD patients, DBS is cost-effective over a one-year period at DBS success rate greater than 35%. Should it prove efficacious, DBS may be cost-effective for patients with AUD and ALD. Thus, future randomized controlled trials to evaluate its efficacy are warranted.

Long-term outcomes of subthalamic nucleus deep brain stimulation for Parkinson's disease in Singapore.

Subthalamic nucleus deep brain stimulation (STN-DBS) is a proven treatment modality for Parkinson's disease (PD), reducing dyskinesia and time spent in the "OFF" state. This study evaluates the long-term outcomes of STN-DBS in PD patients up to 10 years post-surgery in Singapore. We conducted a retrospective review of Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) scores, activities of daily living (ADLs), disease milestones, dopaminergic drug prescriptions, and adverse events in patients before and after STN-DBS surgery. A total of 94 PD patients who underwent bilateral STN-DBS were included. STN-DBS reduced time in the "OFF" state by 36.9% at 1 year (P=0.034) and 40.9% at 5 years (P=0.006). Time with dyskinesia did not significantly change. Levodopa equivalent daily dose was reduced by 35.1% by 5 years (P<0.001). MDS-UPDRS-II and III scores increased from 5 years post-DBS by 40.5% and 35.4%, respectively. Independence in ADLs decreased, though not significantly. The prevalence of frequent falls increased at 5 years. Surgery- and device-related adverse events were uncommon and generally mild. STN-DBS provides sustained relief from motor complications and reduced medication requirements in PD patients in Singapore. This study highlights STN-DBS as an effective treatment option, significantly enhancing the quality of life for those with PD.

Long-term outcomes of subthalamic nucleus deep brain stimulation for Parkinson’s disease in Singapore

Long-term outcomes of subthalamic nucleus deep brain stimulation for Parkinson’s disease in Singapore

Surgicogenomics: The Role of Genetics in Deep Brain Stimulation in Parkinson's Disease Patients.

Parkinson's disease (PD) is the second-most common neurodegenerative disease, affecting 1% of people aged over 60. Currently, there is only symptomatic relief for PD patients, with levodopa being the gold standard of PD treatment. Deep brain stimulation (DBS) is a surgical option to treat PD patients. DBS improves motor functions and may also allow a significant reduction in dopaminergic medication. Important parameters for DBS outcomes are the disease duration, the age of disease onset, responsiveness to levodopa and cognitive or psychiatric comorbidities. Emerging data also highlight the need to carefully consider the genetic background in the preoperative assessment of PD patients who are candidates for DBS, as genetic factors may affect the effectiveness of DBS in these patients. This review article discusses the role of genetics in DBS for PD patients, in an attempt to better understand inter-individual variability in DBS response, control of motor PD symptoms and appearance of non-motor symptoms, especially cognitive decline.

Microelectrode Recording During Deep Brain Stimulation Does Not Consistently Represent Lead Trajectory.

Long-term outcomes in deep brain stimulation (DBS) depend on accuracy of lead placement. Microelectrode recording (MER) is a long-used adjunct to leverage neurophysiological information to confirm satisfactory trajectory of implanted electrodes. The goal of this study was to evaluate the consistency in which electrodes are placed in sampled microelectrode trajectories. This is a retrospective study using intraoperative computed tomography to measure final electrode deviation from MER probe placement during the DBS insertion targeting subthalamic nucleus. Fifteen patients had 29 DBS leads placed using MER assistance. Radial distance between the probe and the lead were measured for each patient using intraoperative imaging. In addition, the preoperative target to final lead error was measured in 14 patients undergoing subthalamic nucleus implants without the use of MER and compared with the 15 patients in which MER was used as an adjunct. There was no significant difference in the mean radial target error (1.2 vs 1.0 mm, P = .156) when comparing the leads placed with or without MER assistance, respectively. The mean difference in final position of microelectrode compared with DBS lead was 0.9 ± 0.1 (range 0.4-2.0 mm). Of all MER-assisted electrodes placed, 44.8% (13) of electrode final positions radially deviated 1.0 mm or more from the MER probe. Electrode placement may deviate significantly from MER trajectories. Given the concern that physiological data may not be representative of the final electrode trajectory, surgeons should consider using intraoperative imaging or other adjunctive techniques during DBS to confirm accuracy and satisfactory trajectory of DBS leads.

Long-term evaluation of anterior thalamic deep brain stimulation for epilepsy in the European MORE registry.

Short-term outcomes of deep brain stimulation of the anterior nucleus of the thalamus (ANT-DBS) were reported for people with drug-resistant focal epilepsy (PwE). Because long-term data are still scarce, the Medtronic Registry for Epilepsy (MORE) evaluated clinical routine application of ANT-DBS. In this multicenter registry, PwE with ANT-DBS were followed up for safety, efficacy, and battery longevity. Follow-up ended after 5 years or upon study closure. Clinical characteristics and stimulation settings were compared between PwE with no benefit, improvers, and responders, that is, PwE with average monthly seizure frequency reduction rates of ≥50%. Of 170 eligible PwE, 104, 62, and 49 completed the 3-, 4-, and 5-year follow-up, respectively. Most discontinuations (68%) were due to planned study closure as follow-up beyond 2 years was optional. The 5-year follow-up cohort had a median seizure frequency reduction from 16 per month at baseline to 7.9 per month at 5-year follow-up (p < .001), with most-pronounced effects on focal-to-bilateral tonic-clonic seizures (n = 15, 77% reduction, p = .008). At last follow-up (median 3.5 years), 41% (69/170) of PwE were responders. Unifocal epilepsy (p = .035) and a negative history of epilepsy surgery (p = .002) were associated with larger average monthly seizure frequency reductions. Stimulation settings did not differ between response groups. In 179 implanted PwE, DBS-related adverse events (AEs, n = 225) and serious AEs (n = 75) included deterioration in epilepsy or seizure frequency/severity/type (33; 14 serious), memory/cognitive impairment (29; 3 serious), and depression (13; 4 serious). Five deaths occurred (none were ANT-DBS related). Most AEs (76.3%) manifested within the first 2 years after implantation. Activa PC depletion (n = 37) occurred on average after 45 months. MORE provides further evidence for the long-term application of ANT-DBS in clinical routine practice. Although clinical benefits increased over time, side effects occurred mainly during the first 2 years. Identified outcome modifiers can help inform PwE selection and management.

Utility of diffusion tensor imaging and generalized q-sampling imaging for predicting short-term clinical effect of deep brain stimulation in Parkinson’s disease

PurposeTo assess whether diffusion tensor imaging (DTI) and generalized q-sampling imaging (GQI) metrics could preoperatively predict the clinical outcome of deep brain stimulation (DBS) in patients with Parkinson’s disease (PD).MethodsIn this single-center retrospective study, from September 2021 to March 2023, preoperative DTI and GQI examinations of 44 patients who underwent DBS surgery, were analyzed. To evaluate motor functions, the Unified Parkinson’s Disease Rating Scale (UPDRS) during on- and off-medication and Parkinson’s Disease Questionnaire-39 (PDQ-39) scales were used before and three months after DBS surgery. The study population was divided into two groups according to the improvement rate of scales: ≥ 50% and < 50%. Five target regions, reported to be affected in PD, were investigated. The parameters having statistically significant difference were subjected to a receiver operating characteristic (ROC) analysis.ResultsQuantitative anisotropy (qa) values from globus pallidus externus, globus pallidus internus (qa_Gpi), and substantia nigra exhibited significant distributional difference between groups in terms of the improvement rate of UPDRS-3 scale during on-medication (p = 0.003, p = 0.0003, and p = 0.0008, respectively). In ROC analysis, the best parameter in predicting DBS response included qa_Gpi with a cut-off value of 0.01370 achieved an area under the ROC curve, accuracy, sensitivity, and specificity of 0.810, 73%, 62.5%, and 85%, respectively. Optimal cut-off values of ≥ 0.01864 and ≤ 0.01162 yielded a sensitivity and specificity of 100%, respectively.ConclusionThe imaging parameters acquired from GQI, particularly qa_Gpi, may have the ability to non-invasively predict the clinical outcome of DBS surgery.

Are LRRK2 p.G2019S or GBA1 variants associated with long-term outcomes of deep brain stimulation for Parkinson’s disease?

Are LRRK2 p.G2019S or GBA1 variants associated with long-term outcomes of deep brain stimulation for Parkinson’s disease?

Structural network topologies are associated with deep brain stimulation outcomes in Meige syndrome

Deep brain stimulation (DBS) is an effective therapy for Meige syndrome (MS). However, the DBS efficacy varies across MS patients and the factors contributing to the variable responses remain enigmatic. We aim to explain the difference in DBS efficacy from a network perspective. We collected preoperative T1-weighted MRI images of 76 MS patients who received DBS in our center. According to the symptomatic improvement rates, all MS patients were divided into two groups: the high improvement group (HIG) and the low improvement group (LIG). We constructed group-level structural covariance networks in each group and compared the graph-based topological properties and interregional connections between groups. Subsequent functional annotation and correlation analyses were also conducted. The results indicated that HIG showed a higher clustering coefficient, longer characteristic path length, lower small-world index, and lower global efficiency compared with LIG. Different nodal betweennesses and degrees between groups were mainly identified in the precuneus, sensorimotor cortex, and subcortical nuclei, among which the gray matter volume of the left precentral gyrus and left thalamus were positively correlated with the symptomatic improvement rates. Moreover, HIG had enhanced interregional connections within the somatomotor network and between the somatomotor network and default-mode network relative to LIG. We concluded that the high and low DBS responders have notable differences in large-scale network architectures. Our study sheds light on the structural network underpinnings of varying DBS responses in MS patients.

No evidence for an association of voxel-based morphometry with short-term non-motor outcomes in deep brain stimulation for Parkinson’s disease

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an established therapy in advanced Parkinson’s disease (PD). Motor and non-motor outcomes, however, show considerable inter-individual variability. Preoperative morphometry-based metrics have recently received increasing attention to explain treatment effects. As evidence for the prediction of non-motor outcomes is limited, we sought to investigate the association between metrics of voxel-based morphometry and short-term non-motor outcomes following STN-DBS in this prospective open-label study. Forty-nine PD patients underwent structural MRI and a comprehensive clinical assessment at preoperative baseline and 6-month follow-up. Voxel-based morphometry was used to assess associations between cerebral volume and non-motor outcomes corrected for multiple comparisons using a permutation-based approach. We replicated existing results associating volume loss of the superior frontal cortex with subpar motor outcomes. Overall non-motor burden, however, was not significantly associated with morphometric features, limiting its use as a marker to inform patient selection and holistic preoperative counselling.

Clinical and Brain Morphometry Predictors of Deep Brain Stimulation Outcome in Parkinson’s Disease

Subthalamic deep brain stimulation (STN-DBS) is known to improve motor function in advanced Parkinson’s disease (PD) and to enable a reduction of anti-parkinsonian medication. While the levodopa challenge test and disease duration are considered good predictors of STN-DBS outcome, other clinical and neuroanatomical predictors are less established. This study aimed to evaluate, in addition to clinical predictors, the effect of patients’ individual brain topography on DBS outcome. The medical records of 35 PD patients were used to analyze DBS outcomes measured with the following scales: Part III of the Unified Parkinson’s Disease Rating Scale (UPDRS-III) off medication at baseline, and at 6-months during medication off and stimulation on, use of anti-parkinsonian medication (LED), Abnormal Involuntary Movement Scale (AIMS) and Non-Motor Symptoms Questionnaire (NMS-Quest). Furthermore, preoperative brain MRI images were utilized to analyze the brain morphology in relation to STN-DBS outcome. With STN-DBS, a 44% reduction in the UPDRS-III score and a 43% decrease in the LED were observed (p<0.001). Dyskinesia and non-motor symptoms decreased significantly [median reductions of 78,6% (IQR 45,5%) and 18,4% (IQR 32,2%) respectively, p=0.001 – 0.047]. Along with the levodopa challenge test, patients’ age correlated with the observed DBS outcome measured as UPDRS-III improvement (ρ= -0.466 – -0.521, p<0.005). Patients with greater LED decline had lower grey matter volumes in left superior medial frontal gyrus, in supplementary motor area and cingulum bilaterally. Additionally, patients with greater UPDRS-III score improvement had lower grey matter volume in similar grey matter areas. These findings remained significant when adjusted for sex, age, baseline LED and UPDRS scores respectively and for total intracranial volume (p=0.0041- 0.001). However, only the LED decrease finding remained significant when the analyses were further controlled for stimulation amplitude. It appears that along with the clinical predictors of STN-DBS outcome, individual patient topographic differences may influence DBS outcome. Clinical Trial Registration Number: NCT06095245, registration date October 23, 2023, retrospectively registered

A Retrospective Comparison of Multiple Approaches to Anatomically Informed Contact Selection in Subthalamic Deep Brain Stimulation for Parkinson's Disease.

Conventional deep brain stimulation (DBS) programming via trial-and-error warrants improvement to ensure swift achievement of optimal outcomes. The definition of a sweet spot for subthalamic DBS in Parkinson's disease (PD-STN-DBS) may offer such advancement. This investigation examines the association of long-term motor outcomes with contact selection during monopolar review and different strategies for anatomically informed contact selection in a retrospective real-life cohort of PD-STN-DBS. We compared contact selection based on a monopolar review (MPR) to multiple anatomically informed contact selection strategies in a cohort of 28 PD patients with STN-DBS. We employed a commercial software package for contact selection based on visual assessment of individual anatomy following two predefined strategies and two algorithmic approaches with automatic targeting of either the sensorimotor STN or our previously published sweet spot. Similarity indices between chronic stimulation and contact selection strategies were correlated to motor outcomes at 12 months follow-up. Lateralized motor outcomes of chronic DBS were correlated to the similarity between chronic stimulation and visual contact selection targeting the dorsal part of the posterior STN (rho = 0.36, p = 0.007). Similar relationships could not be established for MPR or any of the other investigated strategies. Our data demonstrates that a visual contact selection following a predefined strategy can be linked to beneficial long-term motor outcomes in PD-STN-DBS. Since similar correlations could not be observed for the other approaches to anatomically informed contact selection, we conclude that clear definitions and prospective validation of any approach to imaging-based DBS-programming is warranted.

Neural signatures of indirect pathway activity during subthalamic stimulation in Parkinson’s disease

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) produces an electrophysiological signature called evoked resonant neural activity (ERNA); a high-frequency oscillation that has been linked to treatment efficacy. However, the single-neuron and synaptic bases of ERNA are unsubstantiated. This study proposes that ERNA is a subcortical neuronal circuit signature of DBS-mediated engagement of the basal ganglia indirect pathway network. In people with Parkinson’s disease, we: (i) showed that each peak of the ERNA waveform is associated with temporally-locked neuronal inhibition in the STN; (ii) characterized the temporal dynamics of ERNA; (iii) identified a putative mesocircuit architecture, embedded with empirically-derived synaptic dynamics, that is necessary for the emergence of ERNA in silico; (iv) localized ERNA to the dorsal STN in electrophysiological and normative anatomical space; (v) used patient-wise hotspot locations to assess spatial relevance of ERNA with respect to DBS outcome; and (vi) characterized the local fiber activation profile associated with the derived group-level ERNA hotspot.

Association of the Brain Small Vessel Disease Burden with Deep Brain Stimulation Outcome in Parkinson’s Disease (P1-3.006)

Association of the Brain Small Vessel Disease Burden with Deep Brain Stimulation Outcome in Parkinson’s Disease (P1-3.006)

Pallidal multifractal complexity is a new potential physiomarker of dystonia

ObjectiveLow-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. MethodsWe 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. Furthermore, we performed an analysis of LFP recordings from four patients, following the externalization of DBS lead electrodes, to investigate the impact of DBS and neck muscle vibration on multifractal parameters. ResultsGreater dystonia severity exhibited a correlation with a narrower multifractal spectrum width but higher multifractal spectral asymmetry. Both GPi DBS and muscle vibration in dystonia patients expanded the multifractal spectrum width while restoring multifractal spectral symmetry. Notably, the threshold peak intensities for an increase in multifractal spectrum width substantially overlapped with the optimal volume of tissue activated. A broader multifractal spectrum during DBS corresponded to more favorable clinical outcomes. ConclusionsMultifractal properties of pallidal neuronal activity serve as indicators of neural dysfunction in dystonia. SignificanceThese findings suggest the potential of utilizing multifractal characteristics as predictive factors for the DBS outcome in dystonia.

Effect of Deep Brain Stimulation on Parkinson Disease Dementia: A Systematic Review and Meta-analysis.

Patients in the early stages of Parkinson disease (PD) may have subtle cognitive deficits, while overt cognitive deficits are usually manifestations of late-stage PD. There is still a debate on the outcome of deep brain stimulation (DBS) on the cognitive function of PD patients. This study aimed to investigate the effect of subthalamic nucleus (STN)-DBS on the dementia of PD patients after surgery compared to medical therapy and other procedures. We searched PubMed, Scopus, Cochrane Library, and Web of Science database on October 2020, with keywords: "Deep brain stimulation," "Parkinson disease," "dementia," and "memory." Reviews, abstracts, case presentations, and letters were excluded. In total, 491 studies were screened after removing the duplicates. The screening results yielded 81 articles to be screened for eligibility. Finally, 6 studies were included in this meta-analysis for synthesis. Overall, 800 patients were included in this meta-analysis, using the Mattis dementia rating scale (MDRS) and descriptive data from the articles extracted to assess global dementia. Our results suggest that the STN-DBS group showed a larger cognitive decline than the patients receiving the best medical treatment (BMT). However, comparing STN-DBS with globus pallidus interna stimulation and pallidotomy could not demonstrate a significant statistical effect on the global dementia of patients. More long-term studies with larger sample sizes are needed to validate current findings.

7-Tesla Magnetic Resonance Imaging Scanning in Deep Brain Stimulation for Parkinson's Disease: Improving Visualization of the Dorsolateral Subthalamic Nucleus.

Identifying the dorsolateral subthalamic nucleus (STN) for deep brain stimulation (DBS) in Parkinson's disease (PD) can be challenging due to the size and double-oblique orientation. Since 2015 we implemented 7-Tesla T2 weighted magnetic resonance imaging (7 T T2) for improving visualization and targeting of the dorsolateral STN. We describe the changes in surgical planning and outcome since implementation of 7 T T2 for DBS in PD. By comparing two cohorts of STN DBS patients in different time periods we evaluated the influence of 7 T T2 on STN target planning, the number of microelectrode recording (MER) trajectories, length of STN activity and the postoperative motor (UPDRS) improvement. From February 2007 to January 2014, 1.5 and 3-Tesla T2 guided STN DBS with 3 MER channels was performed in 76 PD patients. Average length of recorded STN activity in the definite electrode trajectory was 3.9 ± 1.5 mm. From January 2015 to January 2022 7 T T2 and MER-guided STN DBS was performed in 182 PD patients. Average length of recorded STN activity in the definite electrode trajectory was 5.1 ± 1.3 mm and used MER channels decreased from 3 to 1. Average UPDRS improvement was comparable. Implementation of 7 T T2 for STN DBS enabled a refinement in targeting. Combining classical DBS targeting with dorsolateral STN alignment may be used to determine the optimal trajectory. The improvement in dorsolateral STN visualization can be used for further target refinements, for example adding probabilistic subthalamic connectivity, to enhance clinical outcome of STN DBS.

Motor and Non-motor Outcomes of Deep Brain Stimulation across the Genetic Panorama of Parkinson's Disease: A Multi-Scale Meta-Analysis.

In the era of modern medicine, where high-throughput sequencing techniques are readily available, it is desirable to elucidate the role of genetic background in patients with Parkinson's Disease (PD) undergoing Deep Brain Stimulation (DBS). Genetic stratification of PD patients undergoing DBS may assist in patient selection and prediction of clinical outcomes and complement existing selection procedures such as levodopa challenge testing. To capture a broad spectrum of motor and non-motor DBS outcomes in genetic PD patients with data from the recently updated literature. A multi-scale meta-analysis with 380 genetic PD cases was conducted using the Cochrane Review Manager, JASP software and R. This meta-analysis revealed that overall, patients with genetic PD are good candidates for DBS but the outcomes might differ depending on the presence of specific mutations. PRKN carriers benefited the most regarding motor function, daily dose medication and motor complications. However, GBA carriers appeared to be more prone to cognitive decline after subthalamic nucleus DBS accompanied by a low quality of life with variable severity depending on genetic variants and concomitant alterations in other genes. Apart from GBA, cognitive worsening was also observed in SNCA carriers. Pre-operative levodopa responsiveness and a younger age of onset are associated with a favorable motor outcome. A personalized approach with a variant-based risk stratification within the emerging field of surgicogenomics is needed. Integration of polygenic risk scores in clinical-decision making should be encouraged.

A review on Parkinson’s disease symptoms before and after deep brain stimulation treatment

Introduction: Parkinson’s disease (PD), followed by Alzheimer’s disease, is the most common progressive neurodegenerative disease. Tremors, rigidity, akinesia, and disorders are common PD symptoms. Over the last few decades, deep brain stimulation (DBS) of the subthalamic nucleus has become a standard treatment for advanced PD. The aim of this systematic review paper is to see the difference between the symptoms of PD before and after DBS. Methods: We conducted a literature search using PubMed and Google Scholar. We chose research from the past 10 years. We retrieved 64 papers, and seven duplicated papers were removed. We reviewed the abstract for the remaining 57 papers which led to the selection of 29 papers. After applying inclusion and exclusion criteria for the remaining 29 papers, 23 papers in the English language were chosen for our review. Results: Five Randomized Clinical Trials (RCTs) studied the outcomes of DBS and eight RCTs about effects on posture and motor function. Four RCTs investigated the effects on gait and balance, two on tremors, and the remaining two on posture. The effects of DBS on speech and language were compared in two RCTs. Three studies looked at cognitive performance. One RCT studied sleeping versus awake DBS on PD. These studies showed that with DBS treatment, there was significant improvement in posture, motor function, gait, balance, speech, and language. However, more studies are required for the further analysis on dysphagia and urinary dysfunction. Conclusion: Our study contributed to a better understanding of the advantages of DBS for a range of symptoms, but it concluded that additional RCT on dysphagia and urinary dysfunction was required to reach a reliable conclusion. More research is required to determine the effects of DBS on different motor and non-motor PD symptoms to standardize treatment.