Deep brain stimulation therapy for involuntary movements]

During the last decade, it has become clear that deep brain stimulation (DBS) therapy provides a dramatic improvement in the symptoms of movement disorders. We have experienced DBS in 110 patients with various types of involuntary movements, and confirmed the benefits of stimulation of the thalamic nucleus ventralis intermedius (Vim), internal globus pallidus (GPi) and subthalamic nucleus (STN) in these patients. DBS therapy affords the best effect on tremor when the Vim is selected as the stimulation site. DBS therapy is also useful for controlling rigidity when the GPi or STN is stimulated. Improvements of bradykinesia and gait disturbance are often induced by DBS therapy involving the GPi or STN. Dopa-induced dyskinesia can be attenuated effectively by the direct and/or indirect effects of DBS therapy. DBS of the Vim also provides excellent control of post-stroke involuntary movements, including hemiballism and hemichoreoathetosis. Dystonia in young patients is controlled effectively by DBS of GPi. Ablative procedures for control of involuntary movement disorders, such as thalamotomy and pallidotomy, always carry a risk associated with creating additional lesions in an already damaged brain. In contrast, there is not such a risk in DBS therapy. This modality of therapy is an important option in treating involuntary movements.     

刺激术和毁损术在双侧立体定向手术治疗帕金森病中的比较

目的比较脑深部刺激术和毁损术在双侧立体定向手术治疗帕金森病中的优缺点。方法69例帕金森病病人进行了双侧手术治疗,其中同期双侧丘脑底核(STN)脑深部刺激术(DBS)11例,同期一侧苍白球腹后部毁损术(PVP),另一侧STNDBS3例,分期一侧PVP或腹中间核(Vim)毁损术、另一侧STN或VimDBS9例;分期双侧PVP或Vim毁损术41例,同期双侧PVP5例。平均随访9.3个月。结果UPDRS评分显示刺激术和毁损术均能显著改善对侧肢体震颤、僵硬和运动迟缓症状,双侧刺激术还能改善步态和姿势症状,但双侧毁损术可加重语言、吞咽及流涎等症状,并发症较高。结论双侧DBS是具有双侧症状的帕金森病病人手术治疗的最佳术式,双侧毁损术并发症较高,应严格慎重采用。     

Cognitive and psychiatric outcome 3 years after globus pallidus pars interna or subthalamic nucleus deep brain stimulation for Parkinson's disease

BackgroundEffects on non-motor symptoms, mainly cognitive and psychiatric side effects, could influence the decision for either globus pallidus pars interna (GPi) or subthalamic nucleus (STN) deep brain stimulation (DBS) for patients with Parkinson's disease (PD).Objective1) To compare cognitive and psychiatric outcomes 3 years after GPi DBS versus STN DBS, and 2) to report on occurrence of suicidal ideation, psychiatric diagnoses, social functioning, and marital satisfaction 3 years after DBS.MethodsPatients were randomized to receive GPi DBS (n = 65) or STN DBS (n = 63). Standardized assessments were performed at baseline, 1 year, and 3 years. We used linear mixed model analyses to investigate between-group differences on the Mattis Dementia Rating Scale (MDRS), neuropsychological tests, and psychiatric questionnaires 3 years after DBS.ResultsEighty-seven patients (68%) completed at least one neuropsychological test after 3 years. No significant between-group differences were found on the MDRS (p = 0.61), neuropsychological tests (p-values between 0.17 and 0.87), and psychiatric questionnaires (p-values between 0.23 and 0.88) 3 years after DBS. The Mini International Neuropsychiatric Interview did not indicate a substantial number of psychiatric diagnoses after 3 years. Social functioning and marital satisfaction were comparable in both groups.ConclusionsThree years after GPi DBS and STN DBS no pronounced between-group differences on measures of cognitive and psychiatric functioning could be demonstrated. Overall, cognitive and psychiatric outcome 3 years after DBS do not provide a clear direction for clinicians when considering which of these two surgical targets to choose.     

脑深部电刺激对帕金森病二次手术的临床应用价值

目的探讨帕金森病(Parkinson'sdisease,PD)毁损术后再行脑深部电刺激术(deepbrainstimulation,DBS)的可行性、靶点选择、术中电生理学特点和治疗结果。方法应用MRI和微电极记录技术进行靶点定位,对13例毁损术后的PD患者行DBS手术,其中7例曾行单侧苍白球毁损术(posteroventralpallidotomy,PVP),5例曾行单侧丘脑毁损术,1例曾行双侧丘脑及左侧苍白球毁损术。DBS的靶点包括单侧丘脑底核(subthalamicnucleus,STN)6例,单侧丘脑腹中间核(ventralintermediatnucleus,Vim)1例,双侧STN4例,一侧STN及对侧苍白球(globuspallidusinternus,Gpi)2例。结果DBS对毁损术后的PD患者症状有不同程度的改善,其中单侧毁损术后行双侧DBS效果最明显。术后3个月的UPDRS运动及ADL评分较术前明显减少(P<0.05或0.01),美多巴的用量明显减少(P<0.05),无新的手术合并症。结论曾行毁损术的PD患者如面临二次手术,可以选择DBS手术,以双侧STN的DBS效果最好,并可减少药物用量,不加重原有的术后并发症。     

The actual use of directional steering and shorter pulse width in selected patients undergoing deep brain stimulation

IntroductionDirectional deep brain stimulation (DBS) and pulse with <60μs increase side-effects threshold, enlarging the therapeutic window. However, new systems allowing these advanced features are more expensive and often available only for a limited number of patients in some centers. It is unknown how many and which DBS patients actually need the advanced features because of an insufficient improvement with standard parameters.MethodsWe included in the analysis all patients with Parkinson's disease, dystonia and tremor who were selected to receive implantation of advanced DBS systems based on specific preoperative or intraoperative clinical features.ResultsAfter a median follow-up of 15 months, 54.9% of the 51 patients implanted with directional leads were using the advanced features in one or both leads (n = 42 leads, 42%), meaning these leads were programmed either with directional stimulation (n = 9, 9%), a shorter pw (n = 20, 20%) or both (n = 13, 13%). This included 92% of patients implanted in the Vim, 44% of those implanted in the STN, and 40% of those implanted in the GPi.ConclusionsDBS systems with advanced features may be particularly indicated for selected patients based on some clinical characteristics and the chosen target. This data may help clinicians allocate resources in a more informed way.     

运动障碍性疾病立体定向脑深部刺激术和毁损术中脑出血原因分析

目的 分析运动障碍性疾病立体定向手术中脑出血危险因素,以降低脑出血并发症.方法 对689例运动障碍性疾病进行了立体定向脑深部刺激术(DBS)和毁损术,共有853个靶点进行了手术治疗,其中丘脑底核(STN)刺激术188个,丘脑腹中间核(Vim)刺激术5个,苍白球内侧部DBS 2个,苍白球腹后部毁损术(PVP)478个,Vim毁损术180个.结果 术后无症状性脑出血14例,症状性脑出血10例.有高血压病史患者脑出血发牛率明显高于无高血压病史患者.在微电极记录2-4条针道的手术靶点中,脑出血发生率显著高于微电极记录1条针道的脑出血发生率.DBS、PVP及Vim毁损术靶点脑出血发生率分别为0.5%、3.6%及3.3%,前者发生率明显低于后两者.结论 高血压病史是帕金森病立体定向手术并发脑出血的危险因素,微电极记录针道数与脑出血发生率成明显正相关,脑深部刺激术是较毁损术更安全的外科治疗方法.     

Surgical Treatment of Parkinson’s Disease: Devices and Lesion Approaches

Surgical treatments have transformed the management of Parkinson’s disease (PD). Therapeutic options available for the management of PD motor complications include deep brain stimulation (DBS), ablative or lesioning procedures (pallidotomy, thalamotomy, subthalamotomy), and dopaminergic medication infusion devices. The decision to pursue these advanced treatment options is typically done by a multidisciplinary team by considering factors such as the patient’s clinical characteristics, efficacy, ease of use, and risks of therapy with a goal to improve PD symptoms and quality of life. DBS has become the most widely used surgical therapy, although there is a re-emergence of interest in ablative procedures with the introduction of MR-guided focused ultrasound. In this article, we review DBS and lesioning procedures for PD, including indications, selection process, and management strategies.Electronic supplementary materialThe online version of this article (10.1007/s13311-020-00939-x) contains supplementary material, which is available to authorized users.Key Words: Deep brain stimulation, ablation, RF ablation, stereotactic radiosurgery, focused ultrasound     

Correspondence of optimal stimulation and beta power varies regionally in STN DBS for Parkinson disease

IntroductionSubthalamic nucleus deep brain stimulation (STN DBS) for Parkinson disease (PD) normalizes neuronal hypersynchrony in the beta frequency range (13–30 Hz). The spatial correspondence of maximal beta power to the site of optimal stimulation along the DBS lead trajectory has been debated.MethodsWe determined the trajectory locations of the active contact, maximal beta power, and the dorsal border of the STN (DB-STN) in DBS patients. Beta power profiles were measured during intraoperative microelectrode recording (MER). Active contact locations were assigned during blinded, postoperative DBS programming. The DB-STN was identified both electrophysiologically during MER and anatomically on MRI. After grouping DBS trajectories into quadrants relative to the anatomic STN midpoint, we examined regional variations in the relative trajectory locations of the three entities.ResultsSTN DBS significantly improved motor performance for all 13 DBS patients, with active contacts at the DB-STN. Along trajectories passing posterior-medial to the STN midpoint, maximal beta power co-localized with active contacts at the DB-STN (difference Δ = 0.4 ± 1.6 mm, p = 0.57). By contrast, in posterior-lateral trajectories, maximal beta arose within the STN, ventral to active contacts (Δ = 1.9 ± 1.3 mm, p = 0.002). For trajectories anterior to the STN midpoint, maximal beta power co-localized with the DB-STN, while active contacts were ventral to peak beta power (p = 0.05).ConclusionOur findings indicate that co-localization of optimal stimulation and beta power varies by anatomical region in STN DBS for Parkinson disease.     

脑深部电刺激术治疗毁损术后帕金森病的疗效

目的 探讨脑深部电刺激术（DBS）治疗苍白球或丘脑毁损术后帕金森病的疗效与安全性。方法 回顾性分析2013年1月至2021年3月毁损术后复发或出现新症状而行DBS治疗的33例帕金森病的临床资料。DBS后6个月,采用统一帕金森病量表（UPDRS）运动功能（UPDRS Ⅲ）评分和生活能力（UPDRS Ⅱ）评分、H-Y分期、简明精神量表评分（MMSE）以及左旋多巴等效日剂量（LEDD）评估疗效以及用药情况;记录刺激频率、脉宽、电压、阻抗,并计算刺激能量。结果 术后随访6个月~8.25年,未出现言语障碍、眼球活动障碍、偏瘫、颅内出血或梗死、癫痫发作、颅内感染病例,无硬件故障;5例因电池耗竭行脉冲发生器置换术。DBS后6个月,UPDRS Ⅲ评分、UPDRS Ⅱ评分、H-Y分期、LEDD均较术前明显降低（P<0.05）,而MMSE评分较术前无明显变化（P>0.05）;和非毁损侧相比,毁损侧肢体震颤评分改善率明显增高（P<0.05）,但僵硬评分改善率、运动迟缓评分改善率均无明显变化（P>0.05）;和非毁损侧相比,毁损侧刺激电压和刺激能量明显降低（P<0.05）,但刺激频率、脉宽和阻抗无明显变化（P>0.05）。结论 PD病人神经核团毁损术后复发或出现新症状,DBS是安全、有效的,毁损侧DBS后电刺激所需能量及电压更低。     

Globus pallidus deep brain stimulation for adult-onset axial dystonia

IntroductionGeneralized dystonia, both primary and secondary forms, and axial dystonias such as tardive dystonia, and idiopathic cervical dystonia are responsive to globus pallidus interna (GPi) DBS. There is a paucity of investigations probing the impact of DBS on adult-onset axial dystonia. We assessed the efficacy of GPi DBS in four patients with rare adult-onset axial dystonia.MethodsPrimary outcome measure was improvement in the motor component of the Burke-Fahn-Marsden (BFM) rating scale. Secondary outcome measures were quality of life as determined by the SF-36 questionnaire, time to achieve best possible benefit and DBS parameters that accounted for the best response. In patients with prominent concomitant cervical dystonia we also used the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS).ResultsGPi DBS improved BFM scores by 87.63 ± 11.46%. Improvement in total severity scale of TWSTRS was 71.5 ± 12.7%. Quality of life also remarkably improved as evidenced by 109.38 ± 82.97 and 7.05 ± 21.48% percent change in psychometrically-based physical component summary (PCS), and a mental component summary (MCS) score respectively.ConclusionsGPi DBS is a very effective treatment for adult-onset axial dystonia. Considering its refractoriness to medical therapy and significant impact on quality of life DBS should be considered for this disorder.     

Parkinson's disease motor subtypes and bilateral GPi deep brain stimulation: One-year outcomes

ObjectiveWe aimed to explore the differences in motor symptoms and quality of life (QOL) outcomes following bilateral globus pallidus internus deep brain stimulation (GPi DBS), across well-defined motor subtypes of Parkinson's disease (PD), to improve clinical decision making.MethodsThis single-center retrospective study investigated bilateral GPi DBS outcomes in 65 PD patients. Outcome measures included the Unified Parkinson's Disease Rating Scale (UPDRS) and Parkinson's Disease Questionnaire (PDQ-39) before and one year after surgery. Outcomes were compared between the tremor-dominant (TD) and postural instability and gait difficulty (PIGD) subtypes and between the TD and akinetic-rigid (AR) subtypes.ResultsFor the entire cohort, motor function (UPDRS III) in the Off-medication state, motor complications (UPDRS IV), activities of daily living (ADL, UPDRS II), and the ADL and discomfort domains of PDQ-39 significantly improved one year following GPi implantation compared to baseline (effect size = 1.32, 1.15, 0.25, 0.45, and 0.34, respectively). GPi DBS improved the Off-medication UPDRS III scores regardless of the motor subtypes. However, compared to the PIGD and AR patients, the TD patients showed greater improvement in overall UPDRS III postoperatively primarily due to greater tremor improvement in the Off-medication state. The outcomes in akinesia, rigidity, axial symptoms and QOL were similar among all subtypes.ConclusionBilateral GPi DBS was effective for advanced PD patients regardless of motor subtypes. Greater tremor improvement in the TD patients accounted for greater Off-medication motor improvement. Longer-term GPi DBS outcomes across different motor subtypes and brain targets should be further studied.     

脑深部电刺激治疗帕金森病和特发性震颤的近期和远期疗效

自1987年以后,脑深部电刺激(deep brain stimulation,DBS)成为治疗难治性帕金森病和特发性震颤的主要外科手段。刺激的靶点最先为丘脑腹侧中间核(nucleus ventero-intermedius,Vim)。由于Vim DBS只能缓解震颤,而对于帕金森病的其他核心症状以及多巴长期应用后的不良反应,如运动波动和异动症疗效不显著,1990年后治疗PD的靶点转移到丘脑底核(subthalamic nucleus,STN)和苍白球内侧部(interal globus pallidus,GPi),上述问题在这两个靶点得到显著改善。Vim DBS仍然为治疗特发性震颤的位点。本文就这3个靶点的持续电刺激在治疗帕金森病和特发性震颤的近期和远期疗效等进行评述。     

What Happened to Posteroventral Pallidotomy for Parkinson’s Disease and Dystonia?

Fifteen years after its resurrection, pallidotomy for Parkinson’s disease (PD) and dystonia has once again been supplanted, this time by deep brain stimulation (DBS). Did this occur because pallidotomy was not effective or safe, or because DBS was found to be more effective and safer? This review focuses on the evidence—and its quality—supporting the effectiveness and safety of pallidotomy for PD and dystonia, and the comparative effectiveness and safety of DBS of the subthalamic nucleus (STN) and globus pallidus pars interna (GPi). Discussed first are the determinants of “level 1” recommendations, including the confounding effects on interpretation of randomized clinical trials (RCTs) that fail to control for patient bias (i.e., placebo effects). Although several RCTs have been performed comparing unilateral pallidotomy to medical therapy, GPi DBS, or STN DBS for PD, none controlled for patient bias. Comparison of these trials to estimate the placebo effect, and examination of retrospective case series, suggests that the true effectiveness of unilateral pallidotomy is 20% to 30% reduction of ’off total motor UPDRS scores, which is similar to the effects of unilateral GPi DBS or STN DBS, but less than bilateral STN DBS. At experienced centers, safety of unilateral pallidotomy appears equivalent to unilateral DBS, but bilateral DBS is likely safer than bilateral pallidotomy. Whereas there have been no RCTs of pallidotomy for dystonia, two double-blind, sham-controlled RCTs of bilateral GPi DBS were performed. Nevertheless, limited uncontrolled series suggest that bilateral pallidotomy is similar to GPi DBS in effectiveness and safety for dystonia. Thus, pallidotomy was not rejected because of lack of effectiveness or safety, and it remains a viable alternative in situations where DBS is not available or not feasible.     

Randomized double-blind sham-controlled trial of thalamic versus GPi stimulation in patients with severe medically refractory Gilles de la Tourette syndrome

BackgroundThere are still no sufficient data regarding the use of deep brain stimulation (DBS) in Gilles de la Tourette syndrome (GTS) and no agreement on optimal target.ObjectiveTo compare efficacy and safety of bilateral DBS of thalamus (centromedian-ventro-oral internus, CM-Voi) versus posteroventral lateral globus pallidus internus (pvl GPi)) versus sham stimulation, and baseline in severe medically refractory GTS.MethodsIn this randomized double-blind sham stimulation-controlled trial (RCT), 10 patients (3 women, mean age = 29.4 ± 10.2 SD, range 18–47) underwent three blinded periods each lasting three months including (i) sham, (ii) pvl GPi (on-GPi), and (iii) thalamic stimulation (on-thal) followed by an open uncontrolled long-term follow-up (up to 9 years) with individually determined target and stimulation settings.ResultsNine patients completed the RCT. At group level, on-GPi – but not on-thal – resulted in a significant tic reduction compared to baseline, but had no effect on premonitory urges and psychiatric comorbidities. Direct comparisons of targets resulted in inconsistent or negative (compared to sham) findings. During follow-up, we found no improvement of tics, comorbidities, and quality of life at group level, however, single patients benefitted continuously from thalamic DBS. At last follow-up 89.9 months (mean) after surgery, 50% of patients had discontinued DBS. Hardware infections occurred in 3/10 patients.ConclusionOur data suggest that the initial effect of pvl GPi DBS is superior to thalamic (CM-Voi) DBS. While half of the patients discontinued treatment, single patients benefitted from thalamic DBS even after years. It is likely that outcome is influenced by various factors beyond the mere change in tic severity.     

Prior pallidotomy reduces and modifies neuronal activity in the subthalamic nucleus of Parkinson's disease patients

Parkinson's disease (PD) patients with prior radio-frequency lesions in the internal segment of the globus pallidus (GPi, pallidotomy), whose symptoms have deteriorated, may be candidates for further invasive treatment such as subthalamic deep brain stimulation (STN DBS). Six patients with prior pallidotomy (five unilaterally; one bilaterally) underwent bilateral STN DBS. The microelectrode recordings (MERs, used intraoperatively for STN verification), ipsilateral and contralateral to pallidotomy, and MERs from 11 matched PD patients who underwent bilateral STN DBS without prior pallidotomy were compared. For each trajectory, average, variance and mean successive difference (MSD, a measure of irregularity) of the root mean square (RMS) of the STN MER were calculated. The RMS in trajectories ipsilateral to pallidotomy showed significant reduction of the mean average and MSD of STN activity when compared with trajectories from patients without prior pallidotomy. The RMS parameters contralateral to pallidotomy tend to lie between those ipsilateral to pallidotomy and those without prior pallidotomy. The average STN power spectral density of oscillatory activity was notably lower ipsilateral to pallidotomy than contralateral, or without prior pallidotomy. The finding that pallidotomy reduces STN activity and changes firing characteristics, in conjunction with the effectiveness of STN DBS despite prior pallidotomy, calls for reappraisal and modification of the current model of the basal ganglia (BG) cortical network. It highlights the critical role of direct projections from the BG to brain-stem structures and suggests a possible GPi–STN reciprocal positive-feedback mechanism.     

Asleep Deep Brain Stimulation in Patients With Isolated Dystonia: Stereotactic Accuracy,Efficacy, and Safety

ObjectivesLead placement for deep brain stimulation (DBS) is routinely performed using neuroimaging or microelectrode recording (MER). Recent studies have demonstrated that DBS under general anesthesia using an imaging-guided target technique (“asleep” DBS) can be performed accurately and effectively with lower surgery complication rates than the MER-guided target method under local anesthesia (“awake” DBS). This suggests that asleep DBS may be a more acceptable method. However, there is limited direct evidence focused on isolated dystonia using this method. Therefore, this study aimed to investigate the clinical outcomes and targeting accuracy in patients with dystonia who underwent asleep DBS.Materials and MethodsWe examined 56 patients (112 leads) with isolated dystonia who underwent asleep DBS targeting in the globus pallidus internus (GPi) and subthalamic nucleus (STN). The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores were assessed preoperatively and at 12-month follow-up (12 m-FU). The lead accuracy was evaluated by comparing the coordinates of the preoperative plan with those of the final electrode implantation location. Other measures analyzed included stimulation parameters and adverse events (AEs).ResultsFor both GPi and STN cohorts, mean BFMDRS motor scores were significantly lower at 12 m-FU (8.9 ± 10.9 and 4.6 ± 5.7 points) than at baseline (22.6 ± 16.4 and 16.1 ± 14.1 points, p < 0.001). The mean difference between the planned target and the distal contact of the leads was 1.33 ± 0.54 mm for the right brain electrodes and 1.50 ± 0.57 mm for the left, determined by Euclidian distance. No perioperative complications or AEs related to the device were observed during the complete follow-up. However, AEs associated with stimulation occurred in 12 and 6 patients in the GPi and STN groups, respectively.ConclusionsAsleep DBS may be an accurate, effective, and safe method for treating patients with isolated dystonia regardless of the stimulation target.     

Bilateral Implantation in Globus Pallidus Internus and in Subthalamic Nucleus in Parkinson's Disease

Introduction . Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and of the pars interna of Globus Pallidus (GPi) is used to improve parkinsonian symptoms and attenuate levodopa‐induced motor complications in Parkinson's disease (PD) (DBS for PD study group, 2001). It is still not clear what the best anatomic structures to stimulate are or what the physiologic effects of DBS are. Most of the studies regarding DBS for parkinsonian symptoms have been conducted in patients with STN implantation, and these studies reported significant improvement in motor function with a relatively low rate of complication. The large experience of ablative surgery associated with the DBS experience of some groups worldwide indicate that GPi is a possible and very promising target for the management of parkinsonian symptoms. Surgical procedures have become safer and it is now possible, in selected cases, to target both structures in the same patient by means of the stereotactic system, “3P Maranello” (CLS‐SRL, Italy). Using this system we were able to evaluate the clinical effects of simultaneous stimulation of both STN and GPi as well as evaluate the effects of isolated stimulation of each target. As it is known that there is a high intersubject variability of DBS, it seems relevant to test all different combinations of DBS in the same patient. Methods . We assessed the effects of DBS in 13 cases of PD, immediately after (30 min) stimulation and during chronic stimulation (weeks or months). Patients fell into two groups. The first (n = 7) responded to both GPi and STN stimulation equally. The second group (n = 6) was preferentially stimulated with only one target (STN = 5, GPi = 1). Results . There was a good reduction in levodopa treatment following surgery. Most patients remained were chronically treated with bilateral stimulation of both targets. Conclusion . We conclude that DBS of STN and GPi was effective, with most patients treated chronically with both targets stimulated.     

Surgical targets for dystonic tremor: Considerations between the globus pallidus and ventral intermediate thalamic nucleus

Dystonic tremor (DT) is characterized by coexisting tremor and abnormal dystonic posturing in the same segment. DT is often medically refractory and DBS is an important therapeutic option. However, the optimal surgical target for DT remains uncertain with Vim, GPi and zona incerta previously reported as effective. We retrospectively reviewed the outcome data from all patients with DT involving at least one upper extremity who underwent DBS at Vanderbilt University from July 2006 to July 2010. We evaluated the improvement of tremor and dystonia after their response to DBS was judged to be maximal. Ten patients met the inclusion criteria. Vim was targeted in four patients and three had unilateral procedure and one bilateral Vim DBS. GPi was targeted in four patients with bilateral DBS procedure in every patient from this subgroup. A combined bilateral GPi and unilateral Vim DBS was performed in two patients. The best results for tremor control were observed in patients with Vim DBS but they had persisting mild dystonia. Patients with GPi DBS had average DT improvement by approximately 50% but their dystonia symptoms were markedly improved. We propose that the patients with DT with a mild dystonia should be considered for Vim DBS procedure and the coexistence of severe DT and dystonia may be successfully controlled by combined GPi and Vim DBS surgeries.     

Comparison of intraoperative imaging guided versus microelectrode recording guided deep brain stimulation for Parkinson's disease: A meta-analysis

BackgroundTraditionally, most centers would use microelectrode recording (MER) to refine targeting in deep brain stimulation (DBS) surgery. In recent years, intraoperative imaging (IMG) guided DBS has become an alternative way to verify lead placement. Currently, there is still controversy surrounding the necessity of MER or IMG for DBS. This meta-analysis aims to explore lead accuracy, clinical efficacy and safety between IMG and MER guided DBS for Parkinson's disease (PD).MethodsPubMed, Embase, Web of Science, Cochrane Library were searched up to Mar, 2021 for studies reporting comparisons between IMG and MER guided DBS for PD. Subgroup analysis was conducted to assess effects of different IMG technology and DBS targeting site.ResultsSix studies, comprising of 478 patients were included in our analysis. The mean difference between the two implantation techniques in stereotactic accuracy, lead passes per trajectory, improvement% of Unified Parkinson's Disease Rating Scale part III and levodopa equivalent daily dose were −0.45 (95% confidence interval, CI = −1.11 to 0.20), −0.18 (95% CI = −0.41 to 0.06), 3.40 (95% CI = −5.36 to 12.16), and 5.00 (95% CI = −1.40 to 11.39), respectively. No significant differences were observed in each adverse event and operation/procedure time between the two implantation techniques.ConclusionsBoth IMG and MER guided DBS offered effective control of motor symptoms for PD. Besides, IMG guided is comparable to MER guided DBS, in terms of safety, accuracy and efficiency. It is recommended for each hospital to select DBS guidance technology based on available resources and equipment.     

Posteroventral medial pallidotomy in Parkinson’s disease

There has been a resurgence in the use of functional neurosurgery for Parkinson’s disease. An important factor that has played a role in this development is the recent understanding of the functional anatomy of the basal ganglia including a knowledge of the changes in the activities of neurons in the internal segment of the globus pallidus (GPi) and the subthalamic nucleus (STN) in Parkinson’s disease as well as the knowledge of the presence of segregated functional loops within the basal ganglia which include a sensory-motor loop that involves the posteromedial globus pallidus rather than the anterior GPi where earlier pallidotomy lesions had been made. Laitinen reintroduced the modern posteroventral medial pallidotomy (PVMP) in 1992. Since then it has become clear that this treatment has major effects on levodopa-induced dyskinesias and, unlike Vim thalamotomy, improves bradykinesia and rigidity as well as tremor. In this report, we review a number of topics related to PVMP including the clinical results of pallidotomy available in the literature as well as an update of our own 2 year follow-up data, studies evaluating factors that might predict the subsequent response to pallidotomy, the neuropsychological effects of the procedure, results of imaging studies including the correlation of clinical effects with lesion location, the question of bilateral pallidotomy and pallidotomy combined with deep brain stimulation and finally whether PVMP is effective in other parkinsonian disorders.