Silent Arteriovenous Malformation, Loud Movements: A Dyskinetic Puzzle Resolved by Staged Craniotomy and Immediate Globus Pallidus Internus Deep Brain Stimulation

Primary dystonia is a disabling movement disorder often refractory to medical therapies. While bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) is established for motor symptom control, broader functional outcomes are less well characterized. To evaluate motor and real-world functional improvements following bilateral GPi DBS in patients with primary dystonia. A prospective observational study was conducted on 20 patients (mean age 34.7 years) with medically refractory primary dystonia. All underwent stereotactically guided bilateral GPi DBS. Functional outcomes assessed included skeletal deformity, facial twitching severity, wheelchair dependence, self-feeding ability, and bladder control. Evaluations were conducted at baseline and 6 months postoperatively. McNemar's test and the Wilcoxon signed-rank test were used for statistical analysis. Significant improvements were observed across all domains. Skeletal deformity rates decreased from 95% preoperatively to 10% postoperatively (P < 0.001). Facial twitching improved significantly (P = 0.005). Wheelchair dependence dropped from 50% to 5% (P = 0.007). Self-feeding ability increased from 30% to 95% (P < 0.001), and bladder control improved from 10% to 95% (P < 0.001). No serious adverse events related to surgery or stimulation were reported. Bilateral GPi DBS in primary dystonia significantly improves motor symptoms and critical functional domains such as mobility, independence in self-care, and bladder control. These findings support the broader benefits of DBS, emphasizing its role in enhancing quality of life. Further studies with larger samples and longer follow-up are needed to confirm these outcomes.

Bilateral globus pallidus internus deep brain stimulation for dyskinetic cerebral palsy supports success of cochlear implantation in a 5-year old ex-24week preterm twin with absent cerebellar hemispheres.

We aimed to compare the motor effect of bilateral globus pallidus interna (GPi) deep brain stimulation (DBS) on motor subtypes of Parkinson's disease (PD) patients and identify preoperative predictive factors of short-term motor outcome. We retrospectively investigated bilateral GPi DBS clinical outcomes in 55 PD patients in 1 year follow up. Motor outcome was measured by the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III before and 1 year after surgery. Clinical outcomes were compared among different motor subtypes. Preoperative predictors of motor outcome were assessed by performing univariate and multivariate linear regression and logistic regression analyses. At 1 year following implantation, GPi DBS significantly improved the off-medication MDS-UPDRS III scores in all motor subtype cohorts, with prominent improvement in tremor. No significant difference of postoperative motor symptoms changes was found except greater tremor improvement achieved in both the tremor-dominant (TD) and indeterminate (IND) patients compared to the postural instability and gait difficulty (PIGD) patients. High percentage of PIGD patients were weak responders to DBS. Better levodopa responsiveness and more severe tremor predicted greater overall improvement of motor function in the entire cohort. Similarly, both levodopa responsiveness and tremor improvement were confirmed as predictors for motor improvement in PIGD patients. Bilateral GPi DBS could effectively improve motor outcomes in PD patients regardless of motor subtypes. Both TD and IND patients obtained larger tremor improvement. The intensity of levodopa responsiveness and the severity of tremor could serve as predictors of motor improvement 1 year after GPi DBS.

To compare the effects of subthalamic nucleus (STN) and globus pallidus interna (GPi) deep brain stimulation (DBS) on the motor outcome, gait and balance function, fall risk (FR), and non-motor symptoms in patients with advanced Parkinson's disease (PD). We randomized patients with advanced PD with the indication of DBS to undergo either STN or GPi DBS and followed them for 2 years. We collected data at baseline and postoperative 6, 12, and 24 months. We compared changes in the Unified Parkinson's Disease Rating Scale (UPDRS) score, timed gait tests, posturography, non-motor symptom questionnaire (NMSQuest), hospital anxiety and depression (HAD) scale, and levodopa equivalent dose (LED). We enrolled and randomized 12 patients to receive either STN (n = 6) or GPi (n = 6) DBS. Postoperative motor outcomes were significantly improved in both groups (p < 0.05). In both groups, timed gait tests exhibited better performance in mobility; however, patients receiving GPi DBS performed better than those receiving STN DBS in the timed gait tests (p < 0.05). Furthermore, the posturographic evaluation demonstrated a significant elevation in the FR in the STN group (p < 0.05). Both STN and GPi DBS are equally effective in alleviating disabling motor complications. However, seemingly, STN DBS could cause more gait and balance problems; hence, a tailored approach seems to be more appropriate in the target selection.

Lesch-Nyhan disease (LND) is a hereditary disorder characterized by hyperuricemia, self-mutilation, developmental retardation, and movement disorders such as spasticity and dystonia. The lack of a precise understanding of the neurological dysfunction has precluded the development of useful conservative therapies. We present our experience treating a LND patient by bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) with improvement in dystonia symptoms and disappearance of self-injurious behavior. We present a 29-year-old patient characterized by generalized severe dystonia and self-injurious behavior, both refractory to conservative treatment. The patient underwent a GPi bilateral electrode implant for chronic stimulation. Symptoms were evaluated with the Burke-Fhan-Marsden Dystonia Rating Scale (BFMDRS) and Mean Disability Scale (MDS) preoperatively and during the five-year follow-up. We observed a remarkable improvement in dystonia symptoms and complete disappearance of self-injurious behavior. This case supports the hypothesis that automutilation in LND might be related to dysfunction of the basal ganglia circuits and the idea that bilateral GPi-DBS is a safe and effective treatment modality for this condition.

Subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) are the main surgical approaches for advanced Parkinson's disease. Stimulation is usually applied bilaterally in the same brain structure. However, when various motor symptoms concomitantly present in the same patient, simultaneous modulation of different brain structures may be a suitable alternative. We present a patient with advanced Parkinson's disease with a combined DBS neurosurgery. Left STN DBS optimally controlled the off right hemibody symptomatology while left side troublesome dyskinesias were successfully relieved by right GPi stimulation. Combined STN/GPi stimulation can be considered a suitable approach when challenging motor symptomatology arises in advanced Parkinson's disease patients.

Differential Effects of Subthalamic Nucleus and Globus Pallidus Internus Deep Brain Stimulation on Motor Subtypes in Parkinson's Disease

Objective To compare the therapeutic effects of subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) on Parkinson′s disease (PD) with levodopa-induced dyskinesia (LID), and to explore the possible underlying mechanism. Methods A total of 27 PD patients with LID treated with STN and GPi-DBS from August 2015 to October 2017 at Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University were retrospectively enrolled. Among them, 14 underwent STN-DBS and 13 underwent GPi-DBS. Patients were evaluated preoperatively and every 6, 12, 18 months after surgery. The primary outcome was assessed based on the Unified Dyskinesia Rating Scale (UDysRS). The secondary outcome was investigated according to the Unified Parkinson Disease Rating Scale part Ⅲ (UPDRS-Ⅲ), levodopa equivalent dose (LED), stimulation parameters and side effects. Results Both STN-DBS and GPi-DBS group showed significant improvement in LID, while GPi-DBS exerted higher LID improvement (F=15.326, P 0.05). The improvement of UPDRS-Ⅲ at the 18 month follow-up was 44.7%±20.0% and 45.7%±17.1%, respectively for STN and GPi-DBS. The LED reduction rate was higher in STN-DBS group (F=4.693, P<0.05). The LED reduction rate at the 18 month follow-up was[M(P25, P75)] 44.8(26.7, 80.2)%and 14.0(0, 41.3)%, respectively for STN and GPi-DBS.The stimulation voltage and pulse width of the GPi-DBS group were higher than those of the STN-DBS group (F values were 4.435 and 21.415 respectively, P<0.05). In the STN-DBS group, there were 5 cases of stimulation induced dyskinesia (SID), 1 case of electrode fracture, and 1 case of incision infection.There were 1 case of SID and 1 case of bradykinesia in the GPi-DBS group. Conclusions Both STN and GPi-DBS could improve dyskinesia. Compared with STN-DBS, GPi-DBS seems to have a stronger effect on improvement of LID. The anti-dyskinesia effect of STN-DBS may be related to drug reduction and adjustment of stimulation sites, while GPi-DBS might exert a direct anti-dyskinesia effect. Key words: Deep brain stimulation; Subthalamic nucleus; Globus pallidus internus; Levodopa-induced dyskinesia; Levodopa equivalent dose

Globus pallidus internus (GPi) deep brain stimulation (DBS) was used to treat a stiff-person syndrome (SPS) patient. Prior to implantation, microelectrode recordings measured firing frequencies and patterns (burst index). Contralateral and ipsilateral hemispheres relative to myoclonic jerks on the left side of the body were compared. Analysis revealed significantly lower firing frequencies and significantly higher and more variable burst index in the right contralateral GPi compared to the left ipsilateral GPi.

Spinocerebellar ataxia type 3 (SCA3) is an inherited neurodegenerative disorder. Some of its clinical features resemble those of primary Parkinson’s disease (PD), which can easily lead to misdiagnosis. There is currently no disease-modifying therapy available for SCA3, treatment is mainly symptomatic. Herein, we report a case of a young female patient with SCA3 who presented with Parkinsonian as the main manifestation and underwent globus pallidus internus (GPi) deep brain stimulation (DBS). This is a 36-year-old female patient. Her first symptoms occurred at the age of 28 in 2009, manifesting as gait abnormalities in the right lower limb. She was misdiagnosed with early-onset PD in 2011. Genetic testing showed abnormal numbers of CAG repeats (15/70) within the coding region of the ATXN3 genes. She was diagnosed with SCA3. The patient initially responded well to levodopa-based medication, but the treatment effects gradually attenuated over time, with the development of severe symptom fluctuations and dyskinesia in 2018. The patient underwent GPi-DBS surgery in the absence of cerebellar signs, cognitive, and mood disorders. Six-year postoperative follow-up results suggest that long-term GPi-DBS is effective for the control of dyskinesia, but the residual motor symptoms (parkinsonism and ataxia) had progressively worsened in the patient. Various targets have been reported to be selected for DBS treatment of SCA3, with substantial individual differences in treatment outcomes. This case emphasizes the importance of genetic testing for the diagnosis of SCA3 and provides a basis for personalized treatment of patients with SCA3.

Our aim was to compare in a prospective blinded study the cognitive and mood effects of subthalamic nucleus (STN) vs. globus pallidus interna (GPi) deep brain stimulation (DBS) in Parkinson disease. Fifty-two subjects were randomized to unilateral STN or GPi DBS. The co-primary outcome measures were the Visual Analog Mood Scale, and verbal fluency (semantic and letter) at 7 months post-DBS in the optimal setting compared to pre-DBS. At 7 months post-DBS, subjects were tested in four randomized/counterbalanced conditions (optimal, ventral, dorsal, and off DBS). Forty-five subjects (23 GPi, 22 STN) completed the protocol. The study revealed no difference between STN and GPi DBS in the change of co-primary mood and cognitive outcomes pre- to post-DBS in the optimal setting (Hotelling's T(2) test: p = 0.16 and 0.08 respectively). Subjects in both targets were less "happy", less "energetic" and more "confused" when stimulated ventrally. Comparison of the other 3 DBS conditions to pre-DBS showed a larger deterioration of letter verbal fluency in STN, especially when off DBS. There was no difference in UPDRS motor improvement between targets. There were no significant differences in the co-primary outcome measures (mood and cognition) between STN and GPi in the optimal DBS state. Adverse mood effects occurred ventrally in both targets. A worsening of letter verbal fluency was seen in STN. The persistence of deterioration in verbal fluency in the off STN DBS state was suggestive of a surgical rather than a stimulation-induced effect. Similar motor improvement were observed with both STN and GPi DBS.

Background Deep brain stimulation (DBS) lead revision due to suboptimal therapy is common but there is no standardised protocol. We describe a novel technique using iMRI to perform concurrent new Globus Pallidus Internus (GPi) DBS lead implantation and old lead removal in a dystonia patient. Case-description: A 60-year-old woman with medication and neurotoxin-refractory isolated cervical dystonia underwent awake bilateral GPi DBS surgery with MER-guided lead implantation. She initially had a favourable response but later reported suboptimal benefit despite reprogramming. MRI demonstrated suboptimal lead placement and MRI-guided revision surgery under general anesthesia was planned. The goal was to place new leads superior and medial to the existing leads. Using a 1.5 T iMRI and the ClearPoint® NeuroNavigation system, new leads were placed through the existing burr holes, into the new targets with radial errors < 0.08mm bilaterally without crossing the old leads. The old leads were then removed and the new leads connected to the existing pulse generator. The patient tolerated the procedure well and had improved side-effect profile at all contacts at 1-month follow-up. Conclusions Non-staged iMRI-guided DBS revision surgery under general anesthesia is technically feasible and is an alternative strategy to a staged iMRI-guided revision surgery or an awake MER-guided revision surgery in select patients.

Objective: Bilateral globus pallidus internus deep brain stimulation (GPi-DBS) is an established and effective therapy for primary refractory dystonia. However, the comparison of frameless vs. frame-based DBS surgery technique is still controversial. This retrospective study aims to compare the clinical outcome of two GPi-DBS surgical techniques for patients affected by primary generalized or multi-segmental dystonia.Methods: For lead's stereotaxic placement, 10 patients underwent frame-based surgery and the other 10 subjects DBS surgery with a frameless technique. Clinical features were evaluated at baseline and 6 and 12 months after surgery by means of the Burke–Fahn–Marsden Dystonia Rating Scale.Results: Frame-based GPi-DBS and frameless stereotaxic group revealed a comparable clinical outcome with no surgical complications.Conclusions: Frameless technique is safe and well-tolerated by patients and showed similar effectiveness of the frame-based stereotaxic surgery during GPi-DBS for primary dystonia. Notably, it could be a valid alternative solution because of the great advantage in improving the patient's discomfort during awake surgery.

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.

Bilateral pallidal stimulation for sargoglycan epsilon negative myoclonus.