Post-operative electrode location and clinical efficacy of subthalamic nucleus deep brain stimulation in Meige syndrome

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.

Long-term Efficacy of Bilateral Globus Pallidus Stimulation in the Treatment of Meige Syndrome

OBJECTIVE

This study aimed to investigate the long-term efficacy and prognosis of bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) in patients with benign essential blepharospasm (BEB) and complete Meige syndrome, and to search for the best therapeutic subregion within the GPi.

MATERIALS AND METHODS

Data were collected for 36 patients with Meige syndrome who underwent bilateral GPi-DBS surgery at our hospital between March 2014 and February 2022. Using the Burk-Fahn-Marsden Dystonia Rating Scale (BFMDRS)-Movement (BFMDRS-M) and BFMDRS-Disability (BFMDRS-D), the severity of the symptoms of patients with complete Meige syndrome was evaluated before surgery and at specific time points after surgery. Patients with BEB were clinically evaluated for the severity of blepharospasm using BFMDRS-M, the Blepharospasm Disability Index (BDI), and Jankovic Rating Scale (JRS). Three-dimensional reconstruction of the GPi-electrode was performed in some patients using the lead-DBS software, and the correlation between GPi subregion volume of tissue activated (VTA) and symptom improvement was analyzed in patients six months after surgery. The follow-up duration ranged from six to 99 months.

RESULTS

Compared with preoperative scores, the results of all patients at six months after surgery and final follow-up showed a significant decrease (p < 0.05) in the mean BFMDRS-M score. Among them, the average BFMDRS-M improvement rates in patients with BEB at six months after surgery and final follow-up were 60.3% and 69.7%, respectively, whereas those in patients with complete Meige syndrome were 54.5% and 58.3%, respectively. The average JRS and BDI scores of patients with BEB also decreased significantly (p < 0.05) at six months after surgery and at the final follow-up (JRS improvement: 38.6% and 49.1%, respectively; BDI improvement: 42.6% and 57.4%, respectively). We were unable to identify significantly correlated prognostic factors. There was a significant correlation between GPi occipital VTA and symptom improvement in patients at six months after surgery (r = 0.34, p = 0.025).

CONCLUSIONS

Our study suggests that bilateral GPi-DBS is an effective treatment for Meige syndrome, with no serious postoperative complications. The VTA in the GPi subregion may be related to the movement score improvement. In addition, further research is needed to predict patients with poor surgical outcomes.

Effects of onabotulinum toxin type A injections in patients with Meige's syndrome

BACKGROUND

 Meige's syndrome is a type of facial dystonia characterized by the simultaneous occurrence of blepharospasm and oromandibular dystonia. Although botulinum toxin type A (OBTA) injections are the standard treatment, evidence of their effectiveness and safety in this scenario is still lacking.

OBJECTIVE

 Our research aimed to evaluate the improvement and occurrence of side effects following injections of onabotulinum toxin type A (OBTA) in patients with Meige's syndrome.

METHODS

 Patients with Meige's syndrome undergoing botulinum toxin injections were enrolled in this study. We assessed dystonia intensity before and 14 days after OBTA injection using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) to measure the response of symptoms in the eyes (blepharospasm) and mouth (oromandibular dystonia). Other variables, such as dosage, side effects, and demographic data, were also recorded.

RESULTS

 The study included 41 participants, with a mean age of 67.7 years and a female-to-male ratio of 3.5:1. The mean BFMDRS score before the injections was 8.89, and after 14 days, it was 2.88. The most reported side effect was ptosis, with a 7.3% incidence. OBTA significantly reduced dystonia severity (p < 0.0001). The clinical response for the blepharospasm component was superior to the oromandibular dystonia component.

CONCLUSION

 Our results support that OBTA seems to be an effective and safe therapeutic option for treating Meige's syndrome. The effect of OBTA was more pronounced in the treatment of blepharospasm than in oromandibular dystonia.

Pallidal versus subthalamic deep brain stimulation for Meige syndrome: A systematic review and meta-analysis

Background

Globus pallidus internus (GPi) and subthalamic nucleus (STN) are two common deep brain stimulation (DBS) targets. This meta-analysis was to compared the efficacy and safety of these two DBS targets for the treatment of Meige syndrome (MS).

Methods

A systematic search was performed using EMBASE, MEDLINE, the Cochrane Library, and ClinicalTrials.gov to identify DBS trials for MS. Review Manager 5.3 was used to perform meta-analysis and the mean difference (MD) was analyzed and calculated with a random effect model. Pearson's correlation coefficients and meta-regression analyses were utilized to identify relevant predictive markers.

Results

Twenty trials involving 188 participants with GPi-DBS and 110 individuals with STN-DBS were eligible. Both groups showed improvement of the Burke-Fahn-Marsden Dystonia Rating Scale-Movement (BFMDRS-M) and Disability (BFMDRS-D) scores (BFMDRS-M: MD = 10.57 [7.74-13.41] for GPi-DBS, and MD = 8.59 [4.08-13.11] for STN-DBS; BFMDRS-D: MD = 5.96 [3.15-8.77] for GPi-DBS, and MD = 4.71 [1.38-8.04] for STN-DBS; all P < 0.001) from baseline to the final follow-up, while no notable disparity in improvement rates was observed between them. Stimulation-related complications occurrence was also similar between two groups (38.54 ± 24.07% vs. 43.17 ± 29.12%, P = 0.7594). Simultaneously, preoperative BFMDRS-M score and disease duration were positively connected with the relative changes in BFMDRS-M score at the final visit.

Conclusion

Both GPi-DBS and STN-DBS are effective MS therapies, with no differences in efficacy or the frequency of stimulation-related problems. Higher preoperative scores and longer disease duration probably predict greater improvement.

Subthalamic deep brain stimulation for primary dystonia: defining an optimal location using the medial subthalamic nucleus border as anatomical reference

Introduction

Although the subthalamic nucleus (STN) has proven to be a safe and effective target for deep brain stimulation (DBS) in the treatment of primary dystonia, the rates of individual improvement vary considerably. On the premise of selecting appropriate patients, the location of the stimulation contacts in the dorsolateral sensorimotor area of the STN may be an important factor affecting therapeutic effects, but the optimal location remains unclear. This study aimed to define an optimal location using the medial subthalamic nucleus border as an anatomical reference and to explore the influence of the location of active contacts on outcomes and programming strategies in a series of patients with primary dystonia.

Methods

Data from 18 patients who underwent bilateral STN-DBS were retrospectively acquired and analyzed. Patients were assessed preoperatively and postoperatively (1 month, 3 months, 6 months, 1 year, 2 years, and last follow-up after neurostimulator initiation) using the Toronto Western Spasmodic Torticollis Rating Scale (for cervical dystonia) and the Burke-Fahn-Marsden Dystonia Rating Scale (for other types). Optimal parameters and active contact locations were determined during clinical follow-up. The position of the active contacts relative to the medial STN border was determined using postoperative stereotactic MRI.

Results

The clinical improvement showed a significant negative correlation with the y-axis position (anterior-posterior; A+, P-). The more posterior the electrode contacts were positioned in the dorsolateral sensorimotor area of the STN, the better the therapeutic effects. Cluster analysis of the improvement rates delineated optimal and sub-optimal groups. The optimal contact coordinates from the optimal group were 2.56 mm lateral, 0.15 mm anterior, and 1.34 mm superior relative to the medial STN border.

Conclusion

STN-DBS was effective for primary dystonia, but outcomes were dependent on the active contact location. Bilateral stimulation contacts located behind or adjacent to Bejjani's line were most likely to produce ideal therapeutic effects. These findings may help guide STN-DBS preoperative planning, stimulation programming, and prognosis for optimal therapeutic efficacy in primary dystonia.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Cerebellar gray matter alterations predict deep brain stimulation outcomes in Meige syndrome

BACKGROUND

The physiopathologic mechanism of Meige syndrome (MS) has not been clarified, and neuroimaging studies centering on cerebellar changes in MS are scarce. Moreover, even though deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been recognized as an effective surgical treatment for MS, there has been no reliable biomarker to predict its efficacy.

OBJECTIVE

To characterize the volumetric alterations of gray matter (GM) in the cerebellum in MS and to identify GM measurements related to a good STN-DBS outcome.

METHODS

We used voxel-based morphometry and lobule-based morphometry to compare the regional and lobular GM differences in the cerebellum between 47 MS patients and 52 normal human controls (HCs), as well as between 31 DBS responders and 10 DBS non-responders. Both volumetric analyses were achieved using the Spatially Unbiased Infratentorial Toolbox (SUIT). Further, we performed partial correlation analyses to probe the relationship between the cerebellar GM changes and clinical scores. Finally, we plotted the receiver operating characteristic (ROC) curve to select biomarkers for MS diagnosis and DBS outcomes prediction.

RESULTS

Compared to HCs, MS patients had GM atrophy in lobule Crus I, lobule VI, lobule VIIb, lobule VIIIa, and lobule VIIIb. Compared to DBS responders, DBS non-responders had lower GM volume in the left lobule VIIIb. Moreover, partial correlation analyses revealed a positive relationship between the GM volume of the significant regions/lobules and the symptom improvement rate after DBS surgery. ROC analyses demonstrated that the GM volume of the significant cluster in the left lobule VIIIb could not only distinguish MS patients from HCs but also predict the outcomes of STN-DBS surgery with high accuracy.

CONCLUSION

MS patients display bilateral GM shrinkage in the cerebellum relative to HCs. Regional GM volume of the left lobule VIIIb can be a reliable biomarker for MS diagnosis and DBS outcomes prediction.

Bilateral pallidal DBS for blepharospasm: A case report and review of the literature

Background:

Deep brain stimulation (DBS) of the globus pallidus internus (GPi) in the treatment of craniocervical dystonia often requires an extended period of stimulation parameter manipulations.

Case Description:

We present a patient suffering from debilitating blepharospasm treated with bilateral DBS of the GPi alongside 7 years of stimulation parameter manipulations and a literature review of comparable patients.

Conclusion:

Our literature review suggests that a patient’s specific dystonic symptoms can guide stimulation parameter manipulations. Further research regarding trends in stimulation parameters being used in the field for different dystonic symptoms may expedite the stimulation parameter manipulation process.

Both subthalamic and pallidal deep brain stimulation are effective for GNAO1-associated dystonia: three case reports and a literature review

Background

Mutations in the G-protein subunit alpha o1 (GNAO1) gene have recently been shown to be involved in the pathogenesis of early infantile epileptic encephalopathy and movement disorders. The clinical manifestations of GNAO1-associated movement disorders are highly heterogeneous. However, the genotype-phenotype correlations in this disease remain unclear, and the treatments for GNAO1-associated movement disorders are still limited.

Objective

The objective of this study was to explore diagnostic and therapeutic strategies for GNAO1-associated movement disorders.

Methods

This study describes the cases of three Chinese patients who had shown severe and progressive dystonia in the absence of epilepsy since early childhood. We performed genetic analyses in these patients. Patients 1 and 2 underwent globus pallidus internus (GPi) deep brain stimulation (DBS) implantation, and Patient 3 underwent subthalamic nucleus (STN) DBS implantation. In addition, on the basis of a literature review, we summarized and discussed the clinical characteristics and outcomes after DBS surgery for all reported patients with GNAO1-associated movement disorders.

Results

Whole-exome sequencing (WES) analysis revealed de novo variants in the GNAO1 gene for all three patients, including a splice-site variant (c.724-8G > A) in Patients 1 and 3 and a novel heterozygous missense variant (c.124G > A; p. Gly42Arg) in Patient 2. Both GPi and STN DBS were effective in improving the dystonia symptoms of all three patients.

Conclusion

DBS is effective in ameliorating motor symptoms in patients with GNAO1-associated movement disorders, and both STN DBS and GPi DBS should be considered promptly for patients with sustained refractory GNAO1-associated dystonia.

Deep Brain Stimulation of the Globus Pallidus Internus for Secondary Dystonia: Clinical Cases and Systematic Review of the Literature Regarding the Effectiveness of Globus Pallidus Internus versus Subthalamic Nucleus

OBJECTIVE

Deep brain stimulation (DBS) is a frequently applied therapy in primary dystonia. For secondary dystonia, the effects can be less favorable. We share our long-term findings in 9 patients with severe secondary dystonia and discuss these findings in the light of the literature.

METHODS

Patients who had undergone globus pallidus internus (GPi)-DBS for secondary dystonia were included. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores, clinical improvement rates, follow-up periods, stimulation parameters and the need for internal pulse generator replacements were analyzed. The PubMed and Google Scholar databases were searched for articles describing GPi-DBS and subthalamic nucleus (STN)-DBS only for secondary dystonia cases. Keywords were "dystonia," "deep brain stimulation," "GPi," "dystonia," "deep brain stimulation," and "STN."

RESULTS

A total of 9 secondary dystonia patients (5 male, 4 female) had undergone GPi-DBS with microelectrode recording in our units. The mean follow-up period was 29 months. The average BFMDRS score was 58.2 before the surgery, whereas the mean value was 36.5 at the last follow-up of the patients (mean improvement, 39%; minimum, 9%; maximum, 63%). In the literature review, we identified 264 GPi-DBS cases (mean follow-up, 19 months) in 72 different articles about secondary dystonia. The mean BFMDRS improvement rate was 52%. In 146 secondary dystonia cases, reported in 19 articles, STN-DBS was performed. The average follow-up period was 20 months and the improvement in BFMDRS score was 66%.

CONCLUSIONS

Although GPi-DBS has favorable long-term efficacy and safety in the treatment of patients with secondary dystonia, STN seems a promising target for stimulation in patients with secondary dystonia. Further studies including a large number of patients, longer follow-up periods, and more homogenous patients are necessary to establish the optimal target for DBS in the management of secondary dystonias.

Long-term efficacy of GPi DBS for craniofacial dystonia: a retrospective report of 13 cases

This study evaluated the long-term efficacy of globus pallidus internus (GPi) deep brain stimulation (DBS) in the treatment of craniofacial dystonia (Meige syndrome) and investigated the correlation between the volume of tissue activated (VTA) in the GPi and each subregion and movement score improvement. We retrospectively analyzed the clinical data of 13 patients with drug-refractory Meige syndrome who were treated with GPi DBS. The pre- and postoperative Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores were compared. The relationships between the preoperative baseline variables and improvement in the BFMDRS-Movement (BFMDRS-M) score were analyzed. LEAD-DBS software was used for the three-dimensional reconstruction of the GPi and implanted electrodes. The correlations between the GPi-VTA and score improvement were analyzed. The average follow-up period was 36.6 ± 11.0 months (18-55 months). At 3 months after the stimulation and the final follow-up visit, the improvements in the BFMDRS-M score were 58.2 and 54.6%, and the improvements in the BFMDRS-Disability (BFMDRS-D) score were 53.6 and 51.7%, respectively. At the final follow-up visit, the improvements in the BFMDRS-M scores of the eye, mouth, and speech/swallowing were significant (P < 0.001). Age was an independent predictor of improvement in the BFMDRS-M score after DBS (P = 0.005). A decrease in the BFMDRS-M score was significantly positively correlated with the GPi-VTA (r = 0.757, P = 0.003). GPi DBS is an effective method for treating drug-refractory Meige syndrome. LEAD-DBS software can be used as an effective aid for visualization programming after DBS.

Rescue Subthalamic Deep Brain Stimulation for Refractory Meige Syndrome

Meige syndrome is a segmental form of dystonia. It is a disabling disease, especially when refractory to treatment with botulinum toxin. A well-established therapeutic option is deep brain stimulation (DBS), and the target in bilateral globus pallidus internus (GPi DBS) demonstrated satisfactory short- and long-term efficacy. However, some patients present minor or suboptimal responses after GPi DBS, and in those cases, rescue DBS may be appropriate. The present case illustrates a good outcome after subthalamic nucleus (STN) and not after GPi DBS (considering that both were well positioned and had adequate programming). The larger dimension of the GPi and its somatotopic organization, with the stimulation outside the "face region," could explain our outcomes.

Pallidal versus subthalamic deep-brain stimulation for meige syndrome: a retrospective study

Deep-brain stimulation (DBS) is an effective treatment for patients with Meige syndrome. The globus pallidus interna (GPi) and the subthalamic nucleus (STN) are accepted targets for this treatment. We compared 12-month outcomes for patients who had undergone bilateral stimulation of the GPi or STN. Forty-two Asian patients with primary Meige syndrome who underwent GPi or STN neurostimulation were recruited between September 2017 and September 2019 at the Department of Neurosurgery, Peking University People's Hospital. The primary outcome was the change in motor function, including the Burke-Fahn-Marsden Dystonia Rating Scale movement (BFMDRS-M) and disability subscale (BFMDRS-D) at 3 days before DBS (baseline) surgery and 1, 3, 6, and 12 months after surgery. Secondary outcomes included health-related quality of life, sleep quality status, depression severity, and anxiety severity at 3 days before and 12 months after DBS surgery. Adverse events during the 12 months were also recorded. Changes in BFMDRS-M and BFMDRS-D scores at 1, 3, 6, and 12 months with DBS and without medication did not significantly differ based on the stimulation target. There were also no significant differences in the changes in health-related quality of life (36-Item Short-Form General Health Survey) and sleep quality status (Pittsburgh Sleep Quality Index) at 12 months. However, there were larger improvements in the STN than the GPi group in mean score changes on the 17-item Hamilton depression rating scale (- 3.38 vs. - 0.33 points; P = 0.014) and 14-item Hamilton anxiety rating scale (- 3.43 vs. - 0.19 points; P < 0.001). There were no significant between-group differences in the frequency or type of serious adverse events. Patients with Meige syndrome had similar improvements in motor function, quality of life and sleep after either pallidal or subthalamic stimulation. Depression and anxiety factors may reasonably be included during the selection of DBS targets for Meige syndrome.

Electrophysiological signatures predict clinical outcomes after deep brain stimulation of the globus pallidus internus in Meige syndrome

OBJECTIVE

Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has been shown to be a safe and effective alternative therapy for ameliorating medically refractory primary Meige syndrome. However, the associations between DBS target position and surrounding electrophysiological properties as well as patients' clinical outcomes remains largely unknown. In a large number of patients, we investigated electrophysiological features around stimulation targets and explored their roles in predicting clinical outcomes following bilateral GPi-DBS.

METHODS

The locations of DBS active contacts along the long axis of the GPi in a standard space were calculated and compared among three groups with different clinical outcomes. The firing rates of individual neurons within the GPi were calculated for each patient and compared across the three groups.

RESULTS

Compared with the bad group (poor clinical outcome), active contacts in the good group (good clinical outcome) and the best group (best clinical outcome) were located in the more posterior GPi. The average firing rates in the good and best groups were significantly higher than in the bad group, and this difference was pronounced within the ventral GPi. For the bad group, the average firing rates were significantly lower in the ventral than in the dorsal GPi.

CONCLUSIONS

This study suggests that DBS of the posterior GPi may produce better clinical outcomes during primary Meige syndrome treatment and that higher GPi neuronal activity, particularly within the ventral part, can be used as a biomarker to guide DBS electrode implantation during surgery.

Blepharospasm, Oromandibular Dystonia, and Meige Syndrome: Clinical and Genetic Update

Meige syndrome (MS) is cranial dystonia characterized by the combination of upper and lower cranial involvement and including binocular eyelid spasms (blepharospasm; BSP) and involuntary movements of the jaw muscles (oromandibular dystonia; OMD). The etiology and pathogenesis of this disorder of the extrapyramidal system are not well-understood. Neurologic and ophthalmic examinations often reveal no abnormalities, making diagnosis difficult and often resulting in misdiagnosis. A small proportion of patients have a family history of the disease, but to date no causative genes have been identified to date and no cure is available, although botulinum toxin A therapy effectively mitigates the symptoms and deep brain stimulation is gaining increasing attention as a viable alternative treatment option. Here we review the history and progress of research on MS, BSP, and OMD, as well as the etiology, pathology, diagnosis, and treatment.

Relationship between electrode position of deep brain stimulation and motor symptoms of Parkinson's disease

Background

To investigate the relationship between the position of bilateral STN-DBS location of active contacts and the clinical efficacy of STN-DBS on motor symptoms in Parkinson’s disease (PD) patients.

Methods

Retrospectively analyze the clinical data of 57 patients with PD who underwent bilateral STN-DBS from March 2018 to December 2018. Unified Parkinson’s Disease Rating Scale-Part III (UPDRS-III) score, levodopa equivalent day dose (LEDD), Parkinson’s Disease Quality of Life Scale (PDQ-39) before operation and within 6 months after operation, determine the location of activated contacts and volume of tissue activated (VTA) in the Montreal Neurological Institute (MNI) space, and analyze their correlation with the improvement rate of motor symptoms (UPDRS-III score improvement rate).

Results

After 6 months of follow up, the UPDRS-III scores of 57 patients (Med-off) were improved by 55.4 ± 18.9% (P<0.001) compared with that before operation. The improvement rate of PDQ-39 scores [(47.4 ± 23.2)%, (P < 0.001)] and the reduction rate of LEDD [(40.1 ± 24.3)%, (P < 0.01)] at 6 months postoperation were positively correlated with the improvement rate of motor symptoms (Med-off)(PDQ-39:r = 0.461, P<0.001; LEDD: r = 0.354, P = 0.007), the improvement rate of UPDRS-III (Med-off) and the Z-axis coordinate of the active contact in the MNI space were positively correlated (left side: r = 0.349,P = 0.008;right side: r = 0.369,P = 0.005). In the MNI space, there was no correlation between the UPDRS-III scores improvement rate (Med-off) at 6 months after operation and bilateral VTA in the STN motor subregion, STN associative subregion and STN limbic subregion of the active electrode contacts of 57 patients (all P > 0.05). At 6 months after surgery, the difference between the Z-axis coordinate in the different improvement rate subgroups(<25, 25 to 50%, and>50%) in the MNI space was statistically significant (left side: P = 0.030; right side: P = 0.024). In the MNI space, there was no statistically significant difference between the groups in the VTA of the electrode active contacts (all P > 0.05).

Conclusion

STN-DBS can improve the motor symptoms of PD patients and improve the quality of life. The closer the stimulation is to the STN dorsolateral sensorimotor area, the higher the DBS is to improve the motor symptoms of PD patients.

Similar Long-Term Clinical Outcomes of Deep Brain Stimulation With Different Electrode Targets for Primary Meige Syndrome: One Institution's Experience of 17 Cases

OBJECTIVE

Deep brain stimulation (DBS) is considered an effective and safe treatment for patients with primary Meige syndrome (MS). Both the subthalamic nucleus (STN) and globus pallidus pars internus (Gpi) have been shown to be optional targets for electrode implantation to improve clinical symptoms, but the relationship between clinical outcomes and target is still unclear. The current study aims to compare the clinical outcomes of DBS with different electrode targets for primary MS.

MATERIALS AND METHODS

We performed a retrospective study to assess the clinical outcomes for 17 consecutive patients with primary MS in Wuhan Union Hospital from January 2016 to September 2019. Six patients were treated by Gpi-DBS and 11 patients were treated by STN-DBS. All patients were assessed before surgery and at the last follow-up after surgery. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) including the movement and disability scales was used to evaluate the dystonia severity of the eyes, the mouth, speech, and swallowing. The median follow-up duration was 30.1 ± 13.1 months (range 6 months-52 months).

RESULTS

In our study, DBS improved the BFMDRS-M scores by 70.52 ± 7.45% and the BFMDRS-D scores by 70.51 ± 8.38% for patients with MS. STN-DBS and Gpi-DBS had similar effects not only on the BFMDRS-M and BFMDRS-D scores, but also on the subitems including eyes, mouth, speech, and swallowing. The stimulation voltage for the Gpi was significantly higher than that for the STN. The improvements were similar in the general anesthesia and local anesthesia groups (p > 0.05).

CONCLUSION

The curative effects of STN-DBS and Gpi-DBS on patients with primary MS are similar. Both the STN and Gpi could be effective targets of DBS for primary MS.

Stimulation-Induced Dyskinesia After Subthalamic Nucleus Deep Brain Stimulation in Patients With Meige Syndrome

OBJECTIVES

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is increasingly used to treat Meige syndrome (MS) and markedly improves symptoms. Stimulation-induced dyskinesia (SID), which adversely affects surgical outcomes and patient satisfaction, may, however, occur in some patients. This study attempts to explore possible causes of SID.

MATERIALS AND METHODS

Retrospectively collected clinical data on 32 patients who underwent STN-DBS between October 2016 and April 2019 were analyzed. Clinical outcomes were assessed pre- and post-surgery, using the Burke-Fahn-Marsden dystonia rating scale (BFMDRS). Patients were divided into a dyskinesia group and a non-dyskinesia group, according to whether or not they experienced persistent SID during follow-up. The coordinates of the active contacts were calculated from post-operative computerized tomography or magnetic resonance imaging, using the inter-commissural line as a reference. At final follow-up, the main stimulatory parameters for further study included pulse width, voltage, and frequency.

RESULTS

At final follow-up (mean = 16.3 ± 7.2 months), MS patients had improved BFMDRS total scores compared with pre-surgical scores (mean improvement = 79.0%, p < 0.0001). The mean improvement in BFMDRS total scores in the dyskinesia (n = 10) and non-dyskinesia (n = 22) groups were 81.6 ± 8.8% and 77.9 ± 14.2%, respectively. The mean minimum voltage to induce dyskinesia was 1.7 ± 0.3 V. The programmed parameters of both groups were similar. When compared with the non-dyskinesia group, active stimulatory contact coordinates in the dyskinesia group were inferior (mean left side: z = -2.3 ± 1.7 mm vs. z = -1.2 ± 1.5 mm; p = 0.0282; mean right side: z = -2.7 ± 1.9 mm vs. z = -2.3 ± 1.7 mm; p = 0.0256). The x and y coordinates were similar.

CONCLUSION

STN-DBS is an effective intervention for MS, providing marked improvements in clinical symptoms; SID may, however occur in the subsequent programming control process. Comparing patients with/without dyskinesia, the active contacts were located closer to the inferior part of the STN in patients with dyskinesia, which may provide an explanation for the dyskinesia.

Normative vs. patient-specific brain connectivity in deep brain stimulation

Brain connectivity profiles seeding from deep brain stimulation (DBS) electrodes have emerged as informative tools to estimate outcome variability across DBS patients. Given the limitations of acquiring and processing patient-specific diffusion-weighted imaging data, a number of studies have employed normative atlases of the human connectome. To date, it remains unclear whether patient-specific connectivity information would strengthen the accuracy of such analyses. Here, we compared similarities and differences between patient-specific, disease-matched and normative structural connectivity data and their ability to predict clinical improvement. Data from 33 patients suffering from Parkinson's Disease who underwent surgery at three different centers were retrospectively collected. Stimulation-dependent connectivity profiles seeding from active contacts were estimated using three modalities, namely patient-specific diffusion-MRI data, age- and disease-matched or normative group connectome data (acquired in healthy young subjects). Based on these profiles, models of optimal connectivity were calculated and used to estimate clinical improvement in out of sample data. All three modalities resulted in highly similar optimal connectivity profiles that could largely reproduce findings from prior research based on this present novel multi-center cohort. In a data-driven approach that estimated optimal whole-brain connectivity profiles, out-of-sample predictions of clinical improvements were calculated. Using either patient-specific connectivity (R = 0.43 at p = 0.001), an age- and disease-matched group connectome (R = 0.25, p = 0.048) and a normative connectome based on healthy/young subjects (R = 0.31 at p = 0.028), significant predictions could be made. Our results of patient-specific connectivity and normative connectomes lead to similar main conclusions about which brain areas are associated with clinical improvement. Still, although results were not significantly different, they hint at the fact that patient-specific connectivity may bear the potential of explaining slightly more variance than group connectomes. Furthermore, use of normative connectomes involves datasets with high signal-to-noise acquired on specialized MRI hardware, while clinical datasets as the ones used here may not exactly match their quality. Our findings support the role of DBS electrode connectivity profiles as a promising method to investigate DBS effects and to potentially guide DBS programming.

Subthalamic Nucleus Deep Brain Stimulation in Post-Infarct Dystonia

Dystonia secondary to cerebral infarcts presents months to years after the initial insult, is usually unilateral and causes significant morbidity. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is established as the most frequent target in the management of the dystonic symptoms. We report our experience with subthalamic nucleus (STN) DBS in 3 patients with post-infarct dystonia, in whom GPi DBS was not confidently possible due to the presence of striatal infarcts. Two patients had unilateral STN DBS implantation, whereas the third patient had bilateral STN DBS implantation for bilateral dystonic symptoms. Prospectively collected preoperative and postoperative functional assessment data including imaging, medication and neuropsychology evaluations were analyzed with regard to symptom improvement. Median follow-up period was 38.3 months (range 26–43 months). All patients had clinically valuable improvements in dystonic symptoms and pain control despite variable improvements in the Burke-Fahn-Marsden dystonia rating scores. In our series, we have demonstrated that STN DBS could be an alternative in the management of post-infarct dystonia in patients with abnormal striatal anatomy which precludes GPi DBS. A multidisciplinary team-based approach is essential for patient selection and management.

Deep brain stimulation induced normalization of the human functional connectome in Parkinson's disease

Neuroimaging has seen a paradigm shift away from a formal description of local activity patterns towards studying distributed brain networks. The recently defined framework of the 'human connectome' enables global analysis of parts of the brain and their interconnections. Deep brain stimulation (DBS) is an invasive therapy for patients with severe movement disorders aiming to retune abnormal brain network activity by local high frequency stimulation of the basal ganglia. Beyond clinical utility, DBS represents a powerful research platform to study functional connectomics and the modulation of distributed brain networks in the human brain. We acquired resting-state functional MRI in 20 patients with Parkinson's disease with subthalamic DBS switched on and off. An age-matched control cohort of 15 subjects was acquired from an open data repository. DBS lead placement in the subthalamic nucleus was localized using a state-of-the art pipeline that involved brain shift correction, multispectral image registration and use of a precise subcortical atlas. Based on a realistic 3D model of the electrode and surrounding anatomy, the amount of local impact of DBS was estimated using a finite element method approach. On a global level, average connectivity increases and decreases throughout the brain were estimated by contrasting on and off DBS scans on a voxel-wise graph comprising eight thousand nodes. Local impact of DBS on the motor subthalamic nucleus explained half the variance in global connectivity increases within the motor network (R = 0.711, P < 0.001). Moreover, local impact of DBS on the motor subthalamic nucleus could explain the degree to how much voxel-wise average brain connectivity normalized towards healthy controls (R = 0.713, P < 0.001). Finally, a network-based statistics analysis revealed that DBS attenuated specific couplings known to be pathological in Parkinson's disease. Namely, coupling between motor thalamus and motor cortex was increased while striatal coupling with cerebellum, external pallidum and subthalamic nucleus was decreased by DBS. Our results show that resting state functional MRI may be acquired in DBS on and off conditions on clinical MRI hardware and that data are useful to gain additional insight into how DBS modulates the functional connectome of the human brain. We demonstrate that effective DBS increases overall connectivity in the motor network, normalizes the network profile towards healthy controls and specifically strengthens thalamo-cortical connectivity while reducing striatal control over basal ganglia and cerebellar structures.

Deep brain stimulation: Imaging on a group level

Deep Brain Stimulation (DBS) is an established treatment option for movement disorders and is under investigation for treatment in a growing number of other brain diseases. It has been shown that exact electrode placement crucially affects the efficacy of DBS and this should be considered when investigating novel indications or DBS targets. To measure clinical improvement as a function of electrode placement, neuroscientific methodology and specialized software tools are needed. Such tools should have the goal to make electrode placement comparable across patients and DBS centers, and include statistical analysis options to validate and define optimal targets. Moreover, to allow for comparability across different centers, these need to be performed within an algorithmically and anatomically standardized and openly available group space. With the publication of Lead-DBS software in 2014, an open-source tool was introduced that allowed for precise electrode reconstructions based on pre- and postoperative neuroimaging data. Here, we introduce Lead Group, implemented within the Lead-DBS environment and specifically designed to meet aforementioned demands. In the present article, we showcase the various processing streams of Lead Group in a retrospective cohort of 51 patients suffering from Parkinson's disease, who were implanted with DBS electrodes to the subthalamic nucleus (STN). Specifically, we demonstrate various ways to visualize placement of all electrodes in the group and map clinical improvement values to subcortical space. We do so by using active coordinates and volumes of tissue activated, showing converging evidence of an optimal DBS target in the dorsolateral STN. Second, we relate DBS outcome to the impact of each electrode on local structures by measuring overlap of stimulation volumes with the STN. Finally, we explore the software functions for connectomic mapping, which may be used to relate DBS outcomes to connectivity estimates with remote brain areas. The manuscript is accompanied by a walkthrough tutorial which allows users to reproduce all main results presented here. All data and code needed to reproduce results are openly available.

Subthalamic Nucleus Deep Brain Stimulation in Primary Meige Syndrome: A 1-Year Follow-Up Study

OBJECTIVE

To investigate the efficacy of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with Meige syndrome.

MATERIALS AND METHODS

Fifteen consecutive patients who underwent STN-DBS at the Peking University People's Hospital between September 2017 and June 2018 were included in this study. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) movement score and the BFMDRS disability score were obtained prior to surgery, and at specific time points after surgery. Patients' sleep status was also assessed before and after surgery.

RESULTS

The BFMDRS movement scores decreased from 15.3 ± 4.6 to 5.2 ± 6.2 after STN-DBS, with a mean improvement of 68.6% (p < 0.05). The BFMDRS disability scores were also significantly decreased, from 6.9 ± 3.3 to 3.5 ± 2.9, with a mean improvement of 51.7% (p < 0.05). The eye, mouth, speech, and swallowing movement scores also decreased significantly after STN-DBS compared to baseline (p < 0.05). The sleep quality of the patients was also improved after surgery.

CONCLUSIONS

These findings demonstrate that the STN is an effective brain target for the treatment of patients with Meige syndrome. STN-DBS was not only able to improve patients' motor symptoms, but also their sleep status.

Left Prefrontal Connectivity Links Subthalamic Stimulation with Depressive Symptoms

OBJECTIVE

Subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD) not only stimulates focal target structures but also affects distributed brain networks. The impact this network modulation has on non-motor DBS effects is not well-characterized. By focusing on the affective domain, we systematically investigate the impact of electrode placement and associated structural connectivity on changes in depressive symptoms following STN-DBS, which have been reported to improve, worsen, or remain unchanged.

METHODS

Depressive symptoms before and after STN-DBS surgery were documented in 116 patients with PD from 3 DBS centers (Berlin, Queensland, and Cologne). Based on individual electrode reconstructions, the volumes of tissue activated (VTAs) were estimated and combined with normative connectome data to identify structural connections passing through VTAs. Berlin and Queensland cohorts formed a training and cross-validation dataset used to identify structural connectivity explaining change in depressive symptoms. The Cologne data served as the test-set for which depressive symptom change was predicted.

RESULTS

Structural connectivity was linked to depressive symptom change under STN-DBS. An optimal connectivity map trained on the Berlin cohort could predict changes in depressive symptoms in Queensland patients and vice versa. Furthermore, the joint training-set map predicted changes in depressive symptoms in the independent test-set. Worsening of depressive symptoms was associated with left prefrontal connectivity.

INTERPRETATION

Fibers connecting the electrode with left prefrontal areas were associated with worsening of depressive symptoms. Our results suggest that for the left STN-DBS lead, placement impacting fibers to left prefrontal areas should be avoided to maximize improvement of depressive symptoms. ANN NEUROL 2020;87:962-975.

Deep brain stimulation for Meige syndrome: a meta-analysis with individual patient data

BACKGROUND

Deep brain stimulation (DBS) is an effective intervention for Meige syndrome, a type of dystonia characterized by blepharospasm, facial, and oromandibular dystonia. This individual patient-level data meta-analysis was to identify the potential outcome predictors, compare the stimulation targets and summarize the efficacy of DBS for Meige syndrome.

METHODS

Three electronic databases (PubMed, Web of Science and Embase) were searched with no publication data restriction to identify studies regarding DBS for Meige syndrome. The primary outcome was the improvement in BFMDRS-M score. Pearson's correlation coefficients and a stepwise multivariate regression analysis were used to identify the potential prognostic factors.

RESULTS

Twenty-three studies (115 patients, 94 with pallidal stimulation and 21 with subthalamic stimulation) were eligible. Patients showed significant improvement in Burke-Fahn-Marsden Dystonia Rating Scale movement (BFMDRS-M) (21.5 ± 11.0 vs 8.6 ± 6.9, P < 0.001) and disability (BFMDRS-D) (6.4 ± 5.1 vs 2.9 ± 2.4, P < 0.001) scores at the last follow-up visit (31.9 ± 30.7 months), compared with scores at baseline. Preoperative BFMDRS-M and BFMDRS-D scores were positively correlated with the relative changes in BFMDRS-M score at the last follow-up visit. On the stepwise multivariate regression, only the preoperative BFMDRS remained significant in the best predictive model.

CONCLUSIONS

Based on the existing evidence, pallidal/subthalamic stimulation is an effective therapy for even the refractory Meige syndrome. Higher preoperative scores probably indicate larger improvement. Stimulation targets or other clinical factors do not constitute the outcome predictive factors.