Subthalamic Nucleus Deep Brain Stimulation Research Articles

Localization of deep brain stimulation trajectories via automatic mapping of microelectrode recordings to MRI

Objective. Suboptimal electrode placement during subthalamic nucleus deep brain stimulation (STN DBS) surgery may arise from several sources, including frame-based targeting errors and intraoperative brain shift. We present a computer algorithm that can accurately localize intraoperative microelectrode recording (MER) tracks on preoperative magnetic resonance imaging (MRI) in real-time, thereby predicting deviation between the surgical plan and the MER trajectories. Approach. Random forest (RF) modeling was used to derive a statistical relationship between electrophysiological features on intraoperative MER and voxel intensity on preoperative T2-weighted MR imaging. This model was integrated into a larger algorithm that can automatically localize intraoperative MER recording tracks on preoperative MRI in real-time. To verify accuracy, targeting error of both the planned intraoperative trajectory (‘planned’) and the algorithm-derived trajectory (‘calculated’) was estimated by measuring deviation from the final DBS lead location on postoperative high-resolution computed tomography (‘actual’). Main results. MR imaging and MERs were obtained from 24 STN DBS implant trajectories. The cross-validated RF model could accurately distinguish between gray and white matter regions along MER trajectories (AUC 0.84). When applying this model within the localization algorithm, the calculated MER trajectory estimate was found to be significantly closer to the actual DBS lead when compared to the planned trajectory recorded during surgery (1.04 mm vs 1.52 mm deviation, p < 0.002), with improvement shown in 19/24 cases (79%). When applying the algorithm to simulated DBS trajectory plans with randomized targeting error, up to 4 mm of error could be resolved to <2 mm on average (p < 0.0001). Significance. This work presents an automated system for intraoperative localization of electrodes during STN DBS surgery. This neuroengineering solution may enhance the accuracy of electrode position estimation, particularly in cases where high-resolution intraoperative imaging is not available.

Christmas-Related Reduction in Beta Activity in Parkinson's Disease.

Subthalamic nucleus (STN) beta (13 - 35 Hz) activity is a biomarker reflecting motor state in Parkinson's disease (PD). Adaptive deep brain stimulation (DBS) aims to use beta activity for therapeutic adjustments, but many aspects of beta activity in real-life situations are unknown. The aim was to investigate Christmas-related influences on beta activity in PD. Differences in Christmas Day to nonfestive daily averages in chronic biomarker recordings in 4 PD patients with a sensing-enabled STN DBS implant were retrospectively analyzed. Sweet-spot and whole-brain network connectomic analyses were performed. Beta activity was significantly reduced on Christmas Eve in all patients (4.00-9.00 p.m.: -12.30 ± 10.78%, P=0.015). A sweet spot in the dorsolateral STN connected recording sites to motor, premotor, and supplementary motor cortices. We demonstrate that festive events can reduce beta biomarker activity. We conclude that circadian and holiday-related changes should be considered when tailoring adaptive DBS algorithms to patient demands. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Development and Validation of a Prediction Model for Anxiety Improvement after Deep Brain Stimulation for Parkinson Disease

Parkinson's disease (PD) represents one of the most frequently seen neurodegenerative disorders, while anxiety accounts for its non-motor symptom (NMS), and it has greatly affected the life quality of PD cases. Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) can effectively treat PD. This study aimed to develop a clinical prediction model for the anxiety improvement rate achieved in PD patients receiving STN-DBS. The present work retrospectively enrolled 103 PD cases undergoing STN-DBS. Patients were followed up for 1 year after surgery to analyze the improvement in HAMA scores. Univariate and multivariate logistic regression were conducted to select factors affecting the Hamilton Anxiety Scale (HAMA) improvement. A nomogram was established to predict the likelihood of achieving anxiety improvement. Receiver operating characteristic (ROC) curve analysis, decision curve analysis (DCA), and calibration curve analysis were conducted to verify nomogram performance. The mean improvement in HAMA score was 23.9% in 103 patients; among them, 68.9% had improved anxiety, 25.2% had worsened (Preop) anxiety, and 5.8% had no significant change in anxiety. Education years, UPDRS-III preoperative score, and HAMA preoperative score were independent risk factors for anxiety improvement. The nomogram-predicted values were consistent with real probabilities. Collectively, a nomogram is built in the present work for predicting anxiety improvement probability in PD patients 1 year after STN-DBS. The model is valuable for determining expected anxiety improvement in PD patients undergoing STN-DBS.

Lexicality-Modulated Influence of Auditory Cortex on Subthalamic Nucleus During Motor Planning for Speech.

Speech requires successful information transfer within cortical-basal ganglia loop circuits to produce the desired acoustic output. For this reason, up to 90% of Parkinson's disease patients experience impairments of speech articulation. Deep brain stimulation (DBS) is highly effective in controlling the symptoms of Parkinson's disease, sometimes alongside speech improvement, but subthalamic nucleus (STN) DBS can also lead to decreases in semantic and phonological fluency. This paradox demands better understanding of the interactions between the cortical speech network and the STN, which can be investigated with intracranial EEG recordings collected during DBS implantation surgery. We analyzed the propagation of high-gamma activity between STN, superior temporal gyrus (STG), and ventral sensorimotor cortices during reading aloud via event-related causality, a method that estimates strengths and directionalities of neural activity propagation. We employed a newly developed bivariate smoothing model based on a two-dimensional moving average, which is optimal for reducing random noise while retaining a sharp step response, to ensure precise embedding of statistical significance in the time-frequency space. Sustained and reciprocal neural interactions between STN and ventral sensorimotor cortex were observed. Moreover, high-gamma activity propagated from the STG to the STN prior to speech onset. The strength of this influence was affected by the lexical status of the utterance, with increased activity propagation during word versus pseudoword reading. These unique data suggest a potential role for the STN in the feedforward control of speech.

The mortality of patients with Parkinson's disease with deep brain stimulation.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is effective in improving motor function in patients with Parkinson's disease (PD). This study aimed to investigate mortality associated with bilateral STN DBS in patients with PD and to assess the factors associated with mortality and causes of death after DBS. We reviewed the medical records of 257 patients with PD who underwent bilateral STN DBS at the Movement Disorder Center at Seoul National University Hospital between March 2005 and November 2018. Patients were evaluated preoperatively, at 3, 6, and 12 months after surgery and annually thereafter. The cause and date of death were obtained from interviews with caregivers or from medical certificates at the last follow-up. Of the 257 patients with PD, 48 patients (18.7%) died, with a median time of death of 11.2 years after surgery. Pneumonia was the most common cause of death. Older age of disease onset, preoperative falling score while on medication, and higher preoperative total levodopa equivalent daily dose were associated with a higher risk of mortality in time-dependent Cox regression analysis. These results confirm the mortality outcome of STN DBS in patients with advanced PD.

Impacts of motor phenotype on cognitive function in patients with Parkinson's disease 1 year after subthalamic-nucleus deep brain stimulation.

Parkinson's disease (PD) is a neurological disorder that affects both motor and cognitive functioning. This study aimed to examine the impact of motor phenotype on cognitive function 1 year after subthalamic-nucleus deep brain stimulation (STN-DBS). The prospectively collected data of 37 patients with PD were retrospectively analyzed. The patients were divided into two group according to their motor phenotype: the postural instability and gait disturbance (PIGD) group comprised 16 patients, and the tremor-dominant (TD) group comprised 21 patients. The clinical characteristics and cognitive functions of all patients were examined at baseline and at the 1-year follow-up after STN-DBS. The data showed that STN-DBS significantly improved motor functions (P < 0.05). A repeated-measures analysis of variance indicated a considerable group × time interaction impact on the memory quotient score (P < 0.001) and Tmin (P=0.033). A distinct relationship between the neuropsychological spectrum and motor phenotype of PD patients was observed at the 1-year follow-up after STN-DBS, with worse cognitive outcomes in patients with the PIGD phenotype. Geriatr Gerontol Int 2023; 23: 85-90.

Volume of tissue activated within subthalamic nucleus and clinical efficacy of deep brain stimulation in Meige syndrome.

The clinical efficacy of deep brain stimulation (DBS) relies on the optimal electrode placement in a large extent. Subthalamic nucleus (STN) DBS was recognized as clinically effective for Meige syndrome. This study identified the correlations of volume of tissue activated (VTA) within the motor STN and the final efficacy of the surgical procedure. Clinical outcomes of the patients (n=25) were evaluated with the percentage improvement in Burke-Fahn-Marsden Dystonia Rating Scale movement (BFMDRS-M) scores at the last follow-up (LFU) visit. Pearson's correlation coefficients were calculated to identify the relationship of the final clinical outcomes with the VTA within the STN, VTA within the different STN territories, and other clinical variables. On the whole, the patients showed an average of 59.21% improvement at the LFU visit relative to the baseline (5.72 ± 7.31 vs. 13.70 ± 7.36, P ˂ 0.001). Active electrode contacts mainly clustered in the STN motor territories. There were significant positive correlations between the BFMDRS-M percentage improvement and VTA within the STN (Pearson r = 0.434, P = 0.039) and the STN motor territories (r = 0.430, P = 0.041), but not associative or limbic STN. Other basic clinical characteristics including age, disease duration, and preoperative scores were not significantly correlated with the final outcomes. Our study further validated the efficacy of STN-DBS in even the cases with intractable Meige syndrome. Furthermore, VTA within the motor STN could serve as a potential prognostic factor for the final clinical outcomes.

Utility of movement disorder society-unified Parkinson's disease rating scale for evaluating effect of subthalamic nucleus deep brain stimulation.

The Movement Disorders Society (MDS)-Unified Parkinson's Disease Rating Scale (UPDRS) is increasingly used to assess motor dysfunction before and after subthalamic nucleus deep brain stimulation (STN-DBS). We, therefore, investigated whether the MDS-UPDRS can detect longitudinal changes in motor function after STN-DBS in the same way as UPDRS. We examined 21 patients with Parkinson's disease (PD) (mean age 59.2 ± 10.6 years, mean disease duration 12.0 ± 3.0 years) who underwent STN-DBS and whose motor functions were assessed by the UPDRS and MDS-UPDRS before, 3 months after, and 1 year after STN-DBS. We then evaluated the consistency between the scores of Parts II and III of the UPDRS and MDS-UPDRS during the off phase using Lin's concordance coefficient (LCC) and a Bland-Altman plot. The scores of Parts II and III of both the UPDRS and MDS-UPDRS were significantly decreased 3 months and 1 year after STN-DBS during the off phase. Scores of the UPDRS and MDS-UPDRS showed significant positive correlations before and after STN-DBS. We calculated estimated MDS-UPDRS scores from the UPDRS scores using a regression line and calculated the LCC between the MDS-UPDRS and the estimated MDS-UPDRS scores. The LCC value was 0.59-0.91, which suggests a relatively high consistency between the UPDRS and MDS-UPDRS. The Bland-Altman plot showed that differences between both scores were basically within ±1.96 standard deviations of the difference. The present preliminary study indicated that the utility of the MDS-UPDRS in evaluating motor function before and after STN-DBS demonstrates its potential equivalency to the UPDRS.

Efficacy of Deep Brain Stimulation for Camptocormia in Parkinson's Disease: A Systematic Review and Meta-Analysis.

Camptocormia is one of the most common postural disorders of Parkinson's disease (PD) which has limited treatment options. In this review, we summarize the efficacy of deep brain stimulation (DBS) for camptocormia in PD. The PubMed (https://pubmed.ncbi.nlm.nih.gov/) and EMBASE databases (https://www.embase.com/) were searched for the terms "Parkinson Disease" and "camptocormia" in combination with "deep brain stimulation". We then explored the efficacy of DBS for camptocormia by statistical analysis of the bending angle, the Unified Parkinson's Disease Rating Scale III (UPDRS-III) and L-dopa equivalent daily dose (LEDD), and by evaluating the prognosis after DBS. Twenty articles that reported results for 152 patients were included in this review. These comprised 136 patients from 16 studies who underwent subthalamic nucleus deep brain stimulation (STN-DBS), and 13 patients from 3 studies who underwent globus pallidus internus deep brain stimulation (GPi-DBS). One study used both STN-DBS (2 patients) and GPi-DBS (one patient). After 3-21 months of follow-up, the mean bending angle during the Off-period was significantly reduced compared to pre-DBS (31.5 ± 21.4 vs. 53.6 ± 22.7, respectively; p < 0.0001). For the STN-DBS trials, the mean post-operative bending angles during both Off- and On-periods were significantly reduced compared to pre-operative (32.1 ± 22.7 vs. 55.4 ± 24.1, p = 0.0003; and 33.1 ± 21.5 vs. 43.7 ± 20.6, p = 0.0003, respectively). For GPi-DBS, the mean bending angle post-DBS during the Off-period was considerably lower than pre-DBS (28.5 ± 10.7 vs. 42.9 ± 9.9, p < 0.001). The decrease in bending angle after DBS was negatively correlated with the duration of camptocormia (R = - 0.433, p = 0.013), whereas positively associated with the pre-bending angle (R = 0.352, p = 0.03). DBS is an effective treatment for camptocormia in PD. Patients in the early stage of camptocormia with more significant bending angle may benefit more from DBS.

The effect of subthalamic nucleus deep brain stimulation and dopaminergic treatment on dual-task manual dexterity in Parkinson's disease.

Dual-task manual dexterity is required to perform activities of daily living and is affected by cognitive functions. This study aimed to investigate the effects of two main treatment options, subthalamic nucleus deep brain stimulation (STN-DBS) and dopaminergic treatment (DT), on dual-task manual dexterity and cognitive functions of people with Parkinson's disease (PwPD). Twenty-one PwPD were assessed in four different conditions as medication "on-off" and STN-DBS "on-off" in random order. Motor symptoms were measured with the Movement Disorder Society-Unified Parkinson Disease Rating Scale, motor section (MDS-UPDRS-III). Single and dual-task manual dexterity was assessed with the Nine-Hole Peg Test (NHPT) and cognitive functions were assessed with the Stroop Test (ST) and the Trail Making Test (TMT). Both DT and STN-DBS enhanced MDS-UPDRS-III, and the combination of DT and STN-DBS provided further improvement. Only STN-DBS enhanced dominant hand single-task NHPT scores. Non-dominant single-task NHPT scores and dual-task NHPT scores improved with both treatments alone; however, STN-DBS resulted in more improvement than DT. Dual-task interference, ST, and TMT scores improved with both treatments alone; however, combining DT and STN-DBS did not provide more improvement. DT, STN-DBS, and combining both treatments have different effects on motor symptoms, single and dual-task manual dexterity, dual-task interference, and cognitive functions. These results indicate that DT and STN-DBS may affect motor and cognitive functions via different mechanisms. Effects of DT and STN-DBS on manual dexterity may depend on the degree of cognitive involvement in manual dexterity tasks.

Sex modulates the outcome of subthalamic nucleus deep brain stimulation in patients with Parkinson's disease.

There are many documented sex differences in the clinical course, symptom expression profile, and treatment response of Parkinson's disease, creating additional challenges for patient management. Although subthalamic nucleus deep brain stimulation is an established therapy for Parkinson's disease, the effects of sex on treatment outcome are still unclear. The aim of this retrospective observational study, was to examine sex differences in motor symptoms, non-motor symptoms, and quality of life after subthalamic nucleus deep brain stimulation. Outcome measures were evaluated at 1 and 12 months post-operation in 90 patients with Parkinson's disease undergoing subthalamic nucleus deep brain stimulation aged 63.00 ± 8.01 years (55 men and 35 women). Outcomes of clinical evaluations were compared between sexes via a Student's t-test and within sex via a paired-sample t-test, and generalized linear models were established to identify factors associated with treatment efficacy and intensity for each sex. We found that subthalamic nucleus deep brain stimulation could improve motor symptoms in men but not women in the on-medication condition at 1 and 12 months post-operation. Restless legs syndrome was alleviated to a greater extent in men than in women. Women demonstrated poorer quality of life at baseline and achieved less improvement of quality of life than men after subthalamic nucleus deep brain stimulation. Furthermore, Hoehn-Yahr stage was positively correlated with the treatment response in men, while levodopa equivalent dose at 12 months post-operation was negatively correlated with motor improvement in women. In conclusion, women received less benefit from subthalamic nucleus deep brain stimulation than men in terms of motor symptoms, non-motor symptoms, and quality of life. We found sex-specific factors, i.e., Hoehn-Yahr stage and levodopa equivalent dose, that were related to motor improvements. These findings may help to guide subthalamic nucleus deep brain stimulation patient selection, prognosis, and stimulation programming for optimal therapeutic efficacy in Parkinson's disease.

Sleep outcomes and related factors in Parkinson's disease after subthalamic deep brain electrode implantation: a retrospective cohort study.

Subthalamic nucleus deep brain stimulation (STN-DBS) improves sleep qualities in Parkinson's disease (PD) patients; however, it remains elusive whether STN-DBS improves sleep by directly influencing the sleep circuit or alleviates other cardinal symptoms such as motor functions, other confounding factors including stimulation intensity may also involve. Studying the effect of microlesion effect (MLE) on sleep after STN-DBS electrode implantation may address this issue. To examine the influence of MLE on sleep quality and related factors in PD, as well as the effects of regional and lateral specific correlations with sleep outcomes after STN-DBS electrode implantation. Case-control study; Level of evidence, 3. In 78 PD patients who underwent bilateral STN-DBS surgery in our center, we compared the sleep qualities, motor performances, anti-Parkinsonian drug dosage, and emotional conditions at preoperative baseline and postoperative 1-month follow-up. We determined the related factors of sleep outcomes and visualized the electrodes position, simulated the MLE-engendered volume of tissue lesioned (VTL), and investigated sleep-related sweet/sour spots and laterality in STN. MLE improves sleep quality with Pittsburgh Sleep Quality Index (PSQI) by 13.36% and Parkinson's Disease Sleep Scale-2 (PDSS-2) by 17.95%. Motor (P = 0.014) and emotional (P = 0.001) improvements were both positively correlated with sleep improvements. However, MLE in STN associative subregions, as an independent factor, may cause sleep deterioration (r = 0.348, P = 0.002), and only the left STN showed significance (r = 0.327, P = 0.004). Sweet spot analysis also indicated part of the left STN associative subregion is the sour spot indicative of sleep deterioration. The MLE of STN-DBS can overall improve sleep quality in PD patients, with a positive correlation between motor and emotional improvements. However, independent of all other factors, the MLE in the STN associative subregion, particularly the left side, may cause sleep deterioration.

Deep brain stimulation for Parkinson's disease: A case for patient empowerment

Deep brain stimulation for Parkinson's disease: A case for patient empowerment

Effects of the combined treatment of bilateral subthalamic nucleus stimulation and levodopa on balance and mobility in Parkinson's disease.

<p>Background and purpose &ndash; To evaluate the efficacy of the combined therapy of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) and dopaminergic medication on balance and mobility in patients with Parkinson&rsquo;s disease (PD).</p>. <p>Eighteen PD patients under bilateral STN-DBS stimulation therapy, were enrolled in this study. Unified Parkinson&rsquo;s Disease Rating Scale (UPDRS) was applied to assess the patients&rsquo; clinical characteristics. UPDRS part III postural instability/gait disorder (PIGD) scores (sum of items 3.9-3.13) and UPDRS part III postural stability item (item 3.12) were calculated separately. Patients were evaluated with Berg Balance Scale (BBS), Mini-Balance Evaluation Systems Test (Mini-BESTest), Timed Up and Go (TUG) test, dual-task TUG test, and Forward Functional Reach (FFR) Test in two conditions: Stimulation-ON (stim-ON)/Medication-ON (Med-ON) and Stimulation-OFF (Stim-OFF)/Med-ON.</p>. <p>The mean age of patients was 59.5&plusmn;9.1 (R: 41-71) years. The UPDRS part III total score and PIGD subsection score significantly improved after stimulation (p=0.001), but the postural instability item of the UPDRS part III did not change significantly (p=0.1). There were no significant differences between the Stim-ON/Med-ON and Stim-OFF/Med-ON conditions, in terms of total Mini-BESTest total scores, total BBS score, FFR test score (p&gt;0.05 for all of them). TUG test was significantly improved in the Stim-ON/Med-ON condition compared to Stim-OFF/Med-ON condition (p=0.03), but DT-TUG test did not change (p=0.1).&nbsp;</p>. <p>Combined bilateral STN-DBS and dopaminergic medication therapy had an additional improvement on motor symptoms and mobility performance, but not on balance and dual-task mobility.&nbsp;</p>.

Value of functional connectivity in outcome prediction for pallidal stimulation in Parkinson disease.

Functional connectivity shows the ability to predict the outcome of subthalamic nucleus deep brain stimulation (DBS) in Parkinson disease (PD). However, evidence supporting its value in predicting the outcome of globus pallidus internus (GPi) DBS remains scarce. In this study the authors investigated patient-specific functional connectivity related to GPi DBS outcome in PD and established connectivity models for outcome prediction. The authors reviewed the outcomes of 21 patients with PD who received bilateral GPi DBS and presurgical functional MRI at the Ruijin Hospital. The connectivity profiles within cortical areas identified as relevant to DBS outcome in the literature were calculated using the intersection of the volume of tissue activated (VTA) and the local structures as the seeds. Combined with the leave-one-out cross-validation strategy, models of the optimal connectivity profile were constructed to predict outcome. Connectivity between the pallidal areas and primary motor area, supplementary motor area (SMA), and premotor cortex was identified through the literature as related to GPi DBS outcome. The similarity between the connectivity profile within the primary motor area, SMA, pre-SMA, and premotor cortex seeding from the VTA-GPi intersection from an out-of-sample patient and the constructed in-sample optimal connectivity profile predicts GPi DBS outcome (R = 0.58, p = 0.006). The predictions on average deviated by 13.1% ± 11.3% from actual improvements. On the contrary, connectivity profiles seeding from the GPi (R = -0.12, p = 0.603), the VTA (R = 0.23, p = 0.308), the VTA outside the GPi (R = 0.12, p = 0.617), or other local structures were found not to be predictive. The results showed that patient-specific functional connectivity seeding from the VTA-GPi intersection could help in GPi DBS outcome prediction. Reproducibility remains to be determined across centers in larger cohorts stratified by PD motor subtype.

Study of Impact of Stereotactic parameters on Microelectrode recording in Parkinson’s disease patients who underwent Subthalamic nucleus Deep brain stimulation

Study of Impact of Stereotactic parameters on Microelectrode recording in Parkinson’s disease patients who underwent Subthalamic nucleus Deep brain stimulation

Is Subthalamic Nucleus Deep Brain Stimulation Efficacious in Treating Axial Symptoms in Patients with a Suboptimal Levodopa Response?

Is Subthalamic Nucleus Deep Brain Stimulation Efficacious in Treating Axial Symptoms in Patients with a Suboptimal Levodopa Response?

The altered spontaneous neural activity in patients with Parkinson's disease and its predictive value for the motor improvement of deep brain stimulation

BackgroundThis study aims to investigate the altered spontaneous neural activity in patients with Parkinson's disease (PD) revealed by amplitudes of low-frequency fluctuations (ALFF) of resting-state fMRI, and the feasibility of using ALFF as neuroimaging predictors for motor improvement after bilateral subthalamic nucleus (STN) deep brain stimulation (DBS). MethodsFourty-four patients and 44 healthy controls were included in this study. First, the ALFF of patients with PD was compared with that of controls; then significant clusters were correlated with motor improvement after DBS (unified Parkinson's disease rating scale (UPDRS-III)) and other clinical variables. Second, regression and classification of the machine learning models were conducted to predict motor improvement after DBS. Receiver operating characteristic (ROC) analysis was used to evaluate the performance of the classification model. ResultsCompared with healthy controls, patients with PD showed increased ALFF in the bilateral motor area and decreased ALFF in the bilateral temporal cortex and cerebellum. The Hoehn-Yahr stages correlated with ALFF within the bilateral cerebellum (p = 0.021), and UPDRS-III improvement correlated with ALFF in the left (p < 0.001) and right (p = 0.005) motor areas. The regression model showed a significant correlation between the predicted and observed UPDRS-III changes (R = 0.65, p < 0.001). The ROC analysis revealed an area under the curve (AUC) of 0.94 which differentiated moderate and superior DBS responders. ConclusionThe results revealed altered ALFF patterns in patients with PD and their correlations with clinical variables. Both binary and continuous ALFF can potentially serve as predictive biomarkers for DBS response.

Deep brain stimulation in idiopathic Parkinson’s disease

Parkinson’s disease (PD) is the second most common neurodegenerative and progressive neurological disorder characterized by tremors, rigidity, bradykinesia, and postural instability. Changes of disease in PD pathophysiology are observed in melanin-containing dopaminergic cells in the substantia nigra. While neuronal loss and gliosis are observed in this region, the remaining neurons may contain cytoplasmic inclusions called Lewy bodies. Deep Brain Stimulation (DBS), is the method of application with the highest patient satisfaction among device-assisted treatments in advanced PD. The DBS method is frequently preferred in cases where the disease progresses, drug treatment does not respond, and freezing and on-off dyskinesias begin. The most preferred method among these is subthalamic nucleus (STN) DBS. DBS treatment improves not only motor symptoms but also non-motor symptoms. The success of DBS is based on adequate response to levodopa, appropriate patient selection, successful neuroanatomical and radiological localization of the target area, and a team experienced in motion sickness. Many studies are being conducted to understand the mechanism of action of deep brain stimulation, the effectiveness of which has been proven by various studies. The excitation and suppressive effects provided by the electrodes are processed with a complex neuronal network and clinical results are obtained. In this article, deep brain stimulation tricks, choosing appropriate patients, and mechanisms of action in Parkinson’s disease will be summarized.

Stimulation of the Presupplementary Motor Area Cluster of the Subthalamic Nucleus Predicts More Consistent Clinical Outcomes.

The development of diffusion tensor imaging and tractography has raised increasing interest in the functional targeting of deep brain stimulation of the subthalamic nucleus (STN) in Parkinson disease. To study, using deterministic tractography, the functional subdivisions of the STN and hyperdirect white matter connections located between the STN and the medial frontal cortex, especially the presupplementary motor area (preSMA), SMA, primary motor area (M1), and dorsolateral premotor cortex, and to study retrospectively whether this information correlates with clinical outcome. Twenty-two patients with Parkinson disease who underwent STN deep brain stimulation were analyzed. Using 3 T MR images, the medial frontal cortex was manually segmented into preSMA, SMA, M1, and dorsolateral premotor cortex, which were then used to determine the functional subdivisions of the lateral border of the STN. The intersectional quantities of the volume of activated tissue (VAT) and the hyperdirect white matter connections were calculated. The results were combined with clinical data including unilateral 12-month postoperative motor outcome and levodopa equivalent daily dose. Stimulated clusters of the STN were connected mostly to the cortical SMA and preSMA regions. Patients with primarily preSMA cluster stimulation (presmaVAT% ≥ 50%) had good responses to the treatment with unilateral motor improvement over 40% and levodopa equivalent daily dose reduction over 60%. Larger VAT was not found to correlate with better patient outcomes. Our study is the first to suggest that stimulating, predominantly, the STN cluster where preSMA hyperdirect pathways are located, could be predictive of more consistent treatment results.