Globus Pallidus Internus Deep Brain Stimulation Research Articles

Deep brain stimulation of the globus pallidus internus versus the subthalamic nucleus in isolated dystonia.

Surgical procedures involving deep brain stimulation (DBS) of the globus pallidus internus (GPi) or subthalamic nucleus (STN) are well-established treatments for isolated dystonia. However, selection of the best stimulation target remains a matter of debate. The authors' objective was to compare the effectiveness of DBS of the GPi and the STN in patients with isolated dystonia. In this matched retrospective cohort study, the authors searched an institutional database for data on all patients with isolated dystonia who had undergone bilateral implantation of DBS electrodes in either the GPi or STN in the period from January 30, 2014, to June 30, 2017. Standardized assessments of dystonia and health-related quality of life using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and SF-36 were conducted before and at 1, 6, and 12 months after surgery. No patients were lost to the 6-month follow-up; 5 patients were lost to the 12-month follow-up. Both GPi (14 patients) and STN (16 patients) stimulation produced significant improvement in dystonia and quality of life in all 30 patients found in the database search. At the 1-month follow-up, however, the percentage improvement in the BFMDRS total movement score was significantly (p = 0.01) larger after STN DBS (64%) than after GPi DBS (48%). At the 12-month follow-up, the percentage improvement in the axis subscore was significantly (p = 0.03) larger after GPi DBS (93%) than after STN DBS (83%). Also, the total amount of electrical energy delivered was significantly (p = 0.008) lower with STN DBS than with GPi DBS (124 ± 52 vs 192 ± 65 μJ, respectively). The GPi and STN are both effective targets in alleviating dystonia and improving quality of life. However, GPi stimulation may be better for patients with axial symptoms. Moreover, STN stimulation may produce a larger clinical response within 1 month after surgery and may have a potential economic advantage in terms of lower battery consumption.

Intrathecal Baclofen Pump Versus Globus Pallidus Interna Deep Brain Stimulation in Adult Patients with Severe Cerebral Palsy

There is no consensus on a standardized approach to spasticity or dystonia management of cerebral palsy (CP). This study aimed to investigate clinical outcomes and compare therapeutic responses for pallidal stimulation versus intrathecal baclofen (ITB) therapy in adult patients with severe CP. We retrospectively reviewed patients with CP treated with deep brain stimulation (DBS) of the globus pallidus internus (GPi) or implantation of ITB pump between June 2003 and April 2017. Patients were included if they were clinically diagnosed with medically intractable CP and had >12 months of postprocedural follow-up data. Patients were assessed before and 12 months post-treatment using the visual analogue scale, Burke-Fahn-Marsden Dystonia Rating Scale, self-rating improvement scale, and 36-Item Short-Form General Health Survey Questionnaire. Patients (n= 22) were divided into GPi DBS (n= 12) and ITB therapy (n= 10) groups. For the Burke-Fahn-Marsden Dystonia Rating Scale, DBS group movement scores and ITB group disability scores were significantly improved post-treatment. Although visual analogue scales did not differ between groups, self-rating improvement scores differed significantly between groups. For quality of life, physical functioning, body pain, vitality, social functioning, and mental health significantly improved in ITB group 12 months post-treatment compared with those of preoperative period. Only mental health differed significantly between groups. Despite retrospective design and relatively low number of cases, this study indicated that ITB therapy was less invasive and more effective in improving the quality of life compared with GPi DBS. ITB therapy should be considered an alternative treatment for patients with severe CP.

Change of Extracellular Glutamate Level in Striatum during Deep Brain Stimulation of the Entopeduncular Nucleus in Rats.

ObjectiveGlobus pallidus interna (GPi) is acknowledged as an essential treatment for advanced Parkinson’s disease (PD). Nonetheless, the neurotransmitter study about its results is undiscovered. The goal of this research was to examine influences of entopeduncular nucleus (EPN) stimulation, identical to human GPi, in no-lesioned (NL) rat and 6-hydroxydopamine (6-HD)-lesioned rat on glutamate change in the striatum. MethodsExtracellular glutamate level changes in striatum of NL category, NL with deep brain stimulation (DBS) category, 6-HD category, and 6-HD with DBS category were examined using microdialysis and high-pressure liquid chromatography. Tyrosine hydroxylase (TH) immunoreactivities in substantia nigra and striatum of the four categories were also analyzed. ResultsExtracellular glutamate levels in the striatum of NL with DBS category and 6-HD with DBS category were significantly increased by EPN stimulation compared to those in the NL category and 6-HD category. EPN stimulation had no significant effect on the expression of TH in NL or 6-HD category. ConclusionClinical results of GPi DBS are not only limited to direct inhibitory outflow to thalamus. They also include extensive alteration within basal ganglia.

Long-term outcomes of deep brain stimulation in Parkinson disease.

The efficacy of deep brain stimulation (DBS) for Parkinson disease (PD) is well established for up to 1 or 2 years, but long-term outcome data are still limited. In this Review, wecritically discuss the evidence on the long-term outcomes of DBS and consider the clinical implications. Although many patients are lost to follow-up, the evidence indicates that subthalamic nucleus DBS improves motor function for up to 10 years, although the magnitude ofimprovement tends to decline over time. Functional scores recorded during on-medication periods worsen more quickly than those recorded in off periods, consistent with the degeneration of non-dopaminergic pathways. Dyskinesia, motor fluctuations and activities ofdaily living in off periods remain improved at 5 years, but quality-of-life scores have usually fallen below preoperative levels. The incidence and severity of dementia among patients receiving DBS are comparable to those among patients who receive medical treatment. Severeadverse events are rare, but adverse events such as dysarthria are common and probably under-reported. Long-term data on the outcomes of globus pallidus interna DBS are limited and mostly confirm the efficacy for dyskinesia. A trend towards offering DBS in the earlier stages of PD creates a need to identify factors that predict long-term outcomes and to discuss realistic expectations with patients preoperatively.

Deep brain stimulation for dystonia-choreoathetosis in cerebral palsy: Pallidal versus thalamic stimulation

IntroductionDystonia-choreoathetosis is common in patients with cerebral palsy, and medical treatment is mostly unsatisfactory. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has shown some effect, but there is still a need to optimize treatment strategies. We aimed to assess whether the thalamic ventral intermediate nucleus (Vim) might be an alternative DBS target in dystonia-choreoathetosis. MethodsThree patients with cerebral palsy and dystonia-choreoathetosis underwent implantation of DBS electrodes concurrently in the GPi and Vim. Final selection of stimulation site and switches during follow-up with corresponding clinical outcomes were assessed. ResultsOne patient with initial GPi stimulation was switched to Vim, but likewise did not improve significantly (BFM: pre-OP 142, GPi 140, Vim 134) and stimulation was discontinued. In one patient Vim was chosen as initial target for chronic DBS. Since clinical benefit was not yet satisfying, stimulation was switched to GPi resulting in further mild clinical improvement (BFM: pre-OP 99.5, Vim 82.5, GPi 82). In one patient GPi was selected and kept on follow-up due to some therapeutic effect (BFM: pre-OP 135, GPi DBS 121). ConclusionsThe GPi still represents the most convenient DBS target in patients with dystonia-choreoathetosis. Vim DBS did not show a relevant long-term advantage in everyday life in our patients. Further alternative DBS targets need to be considered in acquired dystonia.

Comparison of Short-Term Stimulation of the Globus Pallidus Interna and Subthalamic Nucleus for Treatment of Primary Dystonia

To compare the efficacy and side effects of bilateral globus pallidus internus (GPi) and subthalamic nucleus (STN) deep brain stimulation (DBS) in the same patient with primary dystonia. Patients with primary dystonia from the department of functional neurosurgery in Beijing Tiantan Hospital were recruited for the study. Four electrodes were bilaterally implanted in the GPi and STN. A trial stimulation was applied to determine the preliminary therapeutic effects. Five evaluations were conducted: preoperative, postoperative (before stimulation), after sham stimulation, and after stimulation for 24 hours of GPi and STN using optimal parameters, judged by the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). The BFMDRS movement score decreased after both short-term GPi stimulation (from 15.3 ± 6.9 to 7.6 ± 4.2, P < 0.05) and short-term STN stimulation (from 15.3 ± 6.9 to 8.6 ± 5.0, P < 0.05). There were significant reductions in facial (eyes and mouth) movement scores after short-term GPi and STN DBS compared with baseline (P < 0.05), but not in cervical symptoms (P > 0.05). The cervical symptoms of tonic dystonia had an improvement after long-term DBS treatment (P < 0.05). There were more adverse events with STN DBS; however, most side effects could be ameliorated by adjusting stimulation parameters. Both short-term GPi and STN stimulation improved the motor symptoms of dystonia, but there was no significant difference between GPi DBS and STN DBS. There were more side effects associated with STN stimulation.

Thalamus Stimulation for Myoclonus Dystonia Syndrome: Five Cases and Long-Term Follow-up

Myoclonic dystonia syndrome (MDS) is a rare inherited movement disorder characterized by the coexistence of myoclonic jerks and dystonia. Deep brain stimulation (DBS) is a promising treatment for patients with MDS that targets the globus pallidus internus or ventral intermediate nucleus (Vim) of the thalamus. However, there are few studies regarding the long-term effects of Vim DBS in patients with MDS and even fewer in those without gene mutations. Two positive and three negative SGCE mutation patients presenting with predominant myoclonus underwent Vim DBS. The Unified Myoclonus Rating Scale and the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) were assessed pre- and postoperation. Over an average follow-up period of 50 months, the myoclonus improvement rate was 92.7%. The average improvement in the BFMDRS motor score was 71.4% and the average improvement in the BFMDRS disabling score was 75.8%. This study suggests that Vim DBS can be a safe and effective treatment option for patients with MDS. Vim DBS alone may be preferable for patients with myoclonus-dominated MDS regardless of the identification of an SGCE mutation. Additional globus pallidus internus DBS may be used for progressive dystonia after Vim DBS.

STN vs. GPi deep brain stimulation for tremor suppression in Parkinson disease: A systematic review and meta-analysis

ObjectiveTo compare subthalamic nucleus (STN) deep brain stimulation (DBS) with globus pallidus interna (GPi) DBS for tremor suppression in Parkinson disease (PD). BackgroundDBS is an effective surgical therapy that has been shown to provide significant benefit for motor symptoms in PD. Currently, two main structures targeted to treat motor complications in PD are the STN and GPi. Although some groups traditionally favor STN over GPi for tremor suppression, evidence demonstrating superiority in long-term tremor control is limited. MethodsWe performed a systematic review for all randomized trials comparing STN vs GPi DBS in PD that were published before March 2017. Five studies were examined in a random effects model meta-analysis. We conducted moderator variable analysis to determine if there was a treatment effect difference for STN versus GPi. ResultsWe compared DBS ON versus OFF and found a significant overall standardized difference mean effect: Effect Size = 0.36; 95% CI = 0.316–0.395; P < 0.0001. These findings indicate that DBS reduced tremor symptoms in PD patients with a medium effect size. Moderator variable analysis of STN vs GPI revealed two significant standardized effect sizes: STN effect size = 0.38 and GPi effect size = 0.35. A Z-test showed that effect sizes between the STN and GPi were not significantly different (P = 0.56). ConclusionsDBS is effective in reducing tremor in PD patients regardless of stimulation target. However, the degree of tremor suppression in STN DBS versus GPi DBS was equivalent.

King’s Parkinson’s Disease Pain Scale for Assessment of Pain Relief Following Deep Brain Stimulation for Parkinson’s Disease

Pain is a prevalent and debilitating nonmotor symptom of Parkinson's disease (PD) that is often inadequately managed. Deep brain stimulation (DBS) has been shown to relieve pain in PD but an effective method of identifying which types of PD pain respond to DBS has not been established. We examine the effects of DBS on different types of PD pain using the King's Parkinson's disease pain scale (KPDPS), the only validated scale of PD pain. We prospectively followed 18 PD patients undergoing subthalamic nucleus (STN) or Globus pallidus interna (GPi) DBS. Subjects completed the KPDPS, low back disability index (LBDI), and McGill pain questionnaire (MPQ), preoperatively and at six months postoperatively. Subjects underwent the unified Parkinson's disease rating scale-III (UPDRS-III) with preoperative scores ON medication and postoperative scores ON medication/DBS stimulation. Of the 18 patients, a total of 12 subjects had STN DBS and 6 had GPi DBS. As a group, subjects showed improvement in total KPDPS score at six-month postoperative follow-up (p = 0.004). Fluctuation and nocturnal pain were most significantly improved (p = 0.006, 0.01, respectively). Significant improvements were found in fluctuation-related pain domain following GPi DBS. In this pilot study, we are the first group to employ KPDPS to monitor pain relief following DBS in PD patients. We demonstrate that fluctuation-related pain and nocturnal pain significantly improve with DBS. Use of the KPDPS in the future will allow better understanding of how STN and GPi DBS treat PD pain over time.

The long-term efficacy of STN vs GPi deep brain stimulation for Parkinson disease: A meta-analysis.

Objective:This meta-analysis assessed the long-term efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus interna (GPi) for Parkinson disease (PD).Methods:PubMed, Cochrane Library, and Clinical Trials databases were searched. Outcomes were unified Parkinson disease rating scale section (UPDRS) III off-medication score, Parkinson's disease questionnaire: 39 activities of daily living (PDQ-39 ADL) score, and levodopa-equivalent dosage after DBS.Results:During the off-medication state, pooled weighted mean difference (WMD) of UPDRS III score was .69 (95% confidence interval [CI] = −1.77 to 3.16, P = .58). In subgroup analysis, WMD of UPDRS III off-medication scores from baseline to 2 years and 3 years post-DBS were −.61 (95% CI = −2.97 to 1.75, P = .61) and 2.59 (95% CI = −2.30 to 7.47, P = .30). Pooled WMD of changes in tremor, rigidity, and gait scores were 1.12 (95% CI = −0.05 to 2.28, P = .06), 1.22 (95% CI = −0.51 to 2.94, P = .17) and .37 (95% CI = −0.13 to 0.87, P = .15), respectively. After DBS, pooled WMD of PDQ-39 ADL and LED were −3.36 (95% CI = −6.36 to −0.36, P = .03) and 194.89 (95% CI = 113.16 to 276.63, P < .001).Conclusions:STN-DBS and GPi-DBS improve motor function and activities of daily living for PD. Differences in the long-term efficacy for PD on motor symptoms were not observed.

Unilateral pallidal stimulation for disabling dystonia due to Rasmussen’s disease

ObjectiveTo describe an adult patient with Rasmussen’s disease with focal dystonia as the most disabling symptom and the good response to unilateral globus pallidus internus (GPi) deep brain stimulation (DBS).MethodsRetrospective...

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Subthalamic Nucleus and Globus Pallidus Internus Deep Brain Stimulation for the Treatment of Patients With Parkinson's Disease: Executive Summary.

Is bilateral subthalamic nucleus deep brain stimulation (STN DBS) more, less, or as effective as bilateral globus pallidus internus deep brain stimulation (GPi DBS) in treating motor symptoms of Parkinson's disease, as measured by improvements in Unified Parkinson's Disease Rating Scale, part III (UPDRS-III) scores? Given that bilateral STN DBS is at least as effective as bilateral GPi DBS in treating motor symptoms of Parkinson's disease (as measured by improvements in UPDRS-III scores), consideration can be given to the selection of either target in patients undergoing surgery to treat motor symptoms. (Level I). Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in allowing reduction of dopaminergic medication in Parkinson's disease? When the main goal of surgery is reduction of dopaminergic medications in a patient with Parkinson's disease, then bilateral STN DBS should be performed instead of GPi DBS. (Level I). Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in treating dyskinesias associated with Parkinson's disease? There is insufficient evidence to make a generalizable recommendation regarding the target selection for reduction of dyskinesias. However, when the reduction of medication is not anticipated and there is a goal to reduce the severity of "on" medication dyskinesias, the GPi should be targeted. (Level I). Is bilateral STN DBS more, less, or as effective as bilateral GPi DBS in improving quality of life measures in Parkinson's disease? When considering improvements in quality of life in a patient undergoing DBS for Parkinson's disease, there is no basis to recommend bilateral DBS in 1 target over the other. (Level I). Is bilateral STN DBS associated with greater, lesser, or a similar impact on neurocognitive function than bilateral GPi DBS in Parkinson disease? If there is significant concern about cognitive decline, particularly in regards to processing speed and working memory in a patient undergoing DBS, then the clinician should consider using GPi DBS rather than STN DBS, while taking into consideration other goals of surgery. (Level I). Is bilateral STN DBS associated with a higher, lower, or similar risk of mood disturbance than GPi DBS in Parkinson's disease? If there is significant concern about the risk of depression in a patient undergoing DBS, then the clinician should consider using pallidal rather than STN stimulation, while taking into consideration other goals of surgery. (Level I). Is bilateral STN DBS associated with a higher, lower, or similar risk of adverse events compared to GPi DBS in Parkinson's disease? There is insufficient evidence to recommend bilateral DBS in 1 target over the other in order to minimize the risk of surgical adverse events. The full guideline can be found at: https://www.cns.org/guidelines/deep-brain-stimulation-parkinsons-disease.

F151. Sensorimotor cortex plasticity correlates with effectiveness of pallidal stimulation in dystonia

Introduction Deep brain stimulation (DBS) of the globus pallidus interna (GPi) is an effective symptomatic treatment of farmacoresistant dystonic syndromes. The sensorimotor cortex of dystonia patients exhibits an exaggerated responsiveness to the TMS (transcranial magnetic stimulation) in conditioning protocols. The aim of our study was to analyse the excitability of the primary motor cortex (MI) in relation to modulation of input from the primary somatosensory cortex (SI) in dystonia patients treated by GPi DBS. Methods We examined 21 patients (mean age 51 ± (SD)17 years) with dystonia treated by GPi DBS. The SI was modulated in DBS ON and OFF conditions by a 2-min series of paired associative stimulation (PAS) with 5 Hz frequency, consisting of electrical stimulation of the median nerve followed by 20 ms of subthreshold TMS pulse. The excitability of the MI was tested by motor evoked potentials (MEP) applied before and after the PAS. The clinical effect (CE) was expressed as a change in the dystonic score between DBS ON condition and the preoperative state. Results The SI PAS caused a decrease of the MEP amplitude in dystonia patients with the GPi DBS ON state in comparison with GPi DBS OFF state ( p p N = 8, p p N = 13, >25% CE) had the MEP amplitude unchanged after the SI PAS in both of the GPi DBS conditions. Conclusion The SI PAS intervention applied over SI cortex affected motor cortex excitability in dystonia patients but not in healthy controls. The GPi DBS reduced the sensorimotor cortex plasticity of dystonia patients under level seen in the GPi DBS off state and even under the level seen in healthy controls. Surprisingly, only poor responders to GPi DBS therapy showed a loss of an inhibitory effect of the SI on the MI immediately after switching stimulation off in comparison with good responders and healthy controls. This may suggest, that the GPi DBS normalizes the excitability of MI through strengthening of the sensorimotor interaction and causes long lasting cortical plasticity changes in good responders which may contribute to better suppression of the dystonic symptoms. Supported by the grants GACR 16-13323S, PROGRES Q27/LF1 and MJFF11362.

Segmentation of the Globus Pallidus Internus Using Probabilistic Diffusion Tractography for Deep Brain Stimulation Targeting in Parkinson Disease.

Although globus pallidus internus deep brain stimulation is a widely accepted treatment for Parkinson disease, there is persistent variability in outcomes that is not yet fully understood. In this pilot study, we aimed to investigate the potential role of globus pallidus internus segmentation using probabilistic tractography as a supplement to traditional targeting methods. Eleven patients undergoing globus pallidus internus deep brain stimulation were included in this retrospective analysis. Using multidirection diffusion-weighted MR imaging, we performed probabilistic tractography at all individual globus pallidus internus voxels. Each globus pallidus internus voxel was then assigned to the 1 ROI with the greatest number of propagated paths. On the basis of deep brain stimulation programming settings, the volume of tissue activated was generated for each patient using a finite element method solution. For each patient, the volume of tissue activated within each of the 10 segmented globus pallidus internus regions was calculated and examined for association with a change in the Unified Parkinson Disease Rating Scale, Part III score before and after treatment. Increasing volume of tissue activated was most strongly correlated with a change in the Unified Parkinson Disease Rating Scale, Part III score for the primary motor region (Spearman r = 0.74, P = .010), followed by the supplementary motor area/premotor cortex (Spearman r = 0.47, P = .15). In this pilot study, we assessed a novel method of segmentation of the globus pallidus internus based on probabilistic tractography as a supplement to traditional targeting methods. Our results suggest that our method may be an independent predictor of deep brain stimulation outcome, and evaluation of a larger cohort or prospective study is warranted to validate these findings.

Estimulação do Globo Pálido Interno para Distonia Focal e Segmentar

Introdução: A distonia pode ser definida como um distúrbio neurológico com a presença de movimentos involuntários com contrações espasmódicas. A estimulação cerebral profunda (DBS) é considerada altamente efetiva em pacientes criteriosamente selecionados e avaliados. A maior efetividade da ECP é demonstrada principalmente nos casos de refratariedade do tratamento clínico e farmacológico na distonia cervical. Objetivo: realizar uma revisão de literatura comprando os resultados da Estimulação Cerebral Profunda no Globo Pálido Interno (GPi), analisando os resultados obtidos no tratamento da distonia focal e segmentar. Métodos: Foram pesquisados no banco de dados do MEDLINE artigos descrevendo DBS para distonia por meio de palavras-chave. Resultados: Foram identificados 308 artigos que envolvem estudos no tratamento de distonia com DBS no GPi. Após aplicar os filtros na base de dados “MEDLINE”, 48 artigos foram excluídos, restando 260 artigos elegíveis. Posteriormente, realizou-se uma revisão minuciosa dos artigos publicados na plataforma em questão. Conclusões: Aponta-se que pacientes com distonia primária são mais beneficiados pelo DBS quando eletrodos são inseridos na porção ventromedial do GPi com taxas de efeitos adversos aceitáveis. Um melhor prognóstico desses pacientes depende de um acompanhamento interdisciplinar individualizado no período pré e pós-operatório.

Clinical outcomes following awake and asleep deep brain stimulation for Parkinson disease.

Recent studies have shown similar clinical outcomes between Parkinson disease (PD) patients treated with deep brain stimulation (DBS) under general anesthesia without microelectrode recording (MER), so-called “asleep” DBS, and historical cohorts undergoing “awake” DBS with MER guidance. However, few studies include internal controls. This study aims to compare clinical outcomes after globus pallidus internus (GPi) and subthalamic nucleus (STN) DBS using awake and asleep techniques at a single institution. PD patients undergoing awake or asleep bilateral GPi or STN DBS were prospectively monitored. The primary outcome measure was stimulation-induced change in motor function off medication 6 months postoperatively, measured using the Unified Parkinson’s Disease Rating Scale part III (UPDRS-III). Secondary outcomes included change in quality of life, measured by the 39-item Parkinson’s Disease Questionnaire (PDQ-39), change in levodopa equivalent daily dosage (LEDD), stereotactic accuracy, stimulation parameters, and adverse events. Six-month outcome data were available for 133 patients treated over 45 months (78 GPi [16 awake, 62 asleep] and 55 STN [14 awake, 41 asleep]). UPDRS-III score improvement with stimulation did not differ between awake and asleep groups for GPi (awake, 20.8 points [38.5%]; asleep, 18.8 points [37.5%]; p = 0.45) or STN (awake, 21.6 points [40.3%]; asleep, 26.1 points [48.8%]; p = 0.20) targets. The percentage improvement in PDQ-39 and LEDD was similar for awake and asleep groups for both GPi (p = 0.80 and p = 0.54, respectively) and STN cohorts (p = 0.85 and p = 0.49, respectively). In PD patients, bilateral GPi and STN DBS using the asleep method resulted in motor, quality-of-life, and medication reduction outcomes that were comparable to those of the awake method.

Subthalamic and Pallidal Deep Brain Stimulation for Parkinson's Disease.

Deep brain stimulation (DBS) is a surgical treatment in which stimulation electrodes are permanently implanted in basal ganglia to treat motor fluctuations and symptoms of Parkinson’s disease (PD). Subthalamic nucleus (STN) and globus pallidus internus (GPi) are the commonly used targets for DBS in PD. Many studies have compared motor and non-motor outcomes of DBS in both targets. However, the selection of PD patients for DBS targets is still poorly studied. Therefore, we performed this narrative review to summarize published studies comparing STN DBS and GPi DBS. GPi DBS is better for patients with problems in speech, mood, or cognition while STN DBS is better from an economic point of view as it allows much reduction in antiparkinson medications and less battery consumption.

Prospective evaluation of Globus pallidus internus deep brain stimulation in Huntington's disease

IntroductionPharmacological treatment of chorea in Huntington's disease (HD) is often limited by poor efficacy or side effects. Pallidal deep brain stimulation (DBS) has been considered in these patients but experience is so far limited. MethodsWe prospectively evaluated the effects of bilateral DBS of the Globus pallidus internus (GPi) over one year in six severely affected HD patients with treatment refractory chorea in an advanced stage of the disease. Primary endpoint of the study was improvement in chorea. Additionally, we evaluated the effects of GPi DBS on the motor part of the Unified Huntington's Disease Rating Scale (UHDRS), bradykinesia, dystonia, functional impairment, psychiatric and cognitive symptoms. Side effects were systematically assessed. ResultsThe chorea subscore was significantly reduced postoperatively (−47% six months, −40% twelve months postoperatively). The UHDRS total motor score was significantly reduced at six months postoperatively (- 17%) but the effect was not sustained twelve months after the operation (- 5%). Pallidal DBS did not improve other motor symptoms or functional impairment. There was no effect on psychiatric symptoms or cognition. A number of side effects were noted, especially spasticity in three of the patients. ConclusionsPallidal DBS is a treatment option for HD patients with severe pharmacologically refractory chorea. Further studies are needed to define optimal candidates for this procedure.

Long-term outcome of pallidal stimulation for Meige syndrome.

OBJECTIVE Meige syndrome is characterized by blepharospasm and varied subphenotypes of craniocervical dystonia. Current literature on pallidal surgery for Meige syndrome is limited to case reports and a few small-scale studies. The authors investigated the clinical outcomes of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in patients with Meige syndrome. METHODS Sixteen patients who underwent GPi DBS at the Tokyo Women's Medical University Hospital between 2002 and 2015 were included in this study. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) movement subscale (BFMDRS-M) scores (range 0-120) obtained at the following 3 time points were included in this analysis: before surgery, 3 months after surgery, and at the most recent follow-up evaluation. RESULTS The patients' mean age (± SD) at symptom onset was 46.7 ± 10.1 years, and the mean disease duration at the time of the authors' initial evaluation was 5.9 ± 4.1 years. In 12 patients, the initial symptom was blepharospasm, and the other 4 patients presented with cervical dystonia. The mean postoperative follow-up period was 66.6 ± 40.7 months (range 13-150 months). The mean total BFMDRS-M scores at the 3 time points were 16.3 ± 5.5, 5.5 ± 5.6 (66.3% improvement, p < 0.001), and 6.7 ± 7.3 (58.9% improvement, p < 0.001). CONCLUSIONS The results indicate long-term efficacy for GPi DBS for the majority of patients with Meige syndrome.

Pallidal deep brain stimulation for dystonia: a long term study

BackgroundPallidal deep brain stimulation (globus pallidus internus (GPi) DBS) is the best therapeutic option for disabling isolated idiopathic (IID) and inherited (INH) dystonia. Acquired dystonia (AD) may also benefit from...