Asleep versus awake GPi DBS surgery for Parkinson's disease: A systematic review and meta-analysis.

BACKGROUND: Patients with Parkinson's Disease (PD) who receive either asleep image-guided subthalamic nucleus deep brain stimulation (DBS) or the traditional awake technique have comparable motor outcomes. However, there are fewer studies regarding which technique should be chosen for globus pallidus internus (GPi) DBS. This systematic review and meta-analysis aims to compare the accuracy of lead placement and motor outcomes of asleep versus awake GPi DBS PD population. METHODS: We systematically searched PubMed, Embase, and Cochrane for studies comparing asleep vs. awake GPi DBS lead placement in patients with PD. Outcomes were spatial accuracy of lead placement, measured by radial error between intended and actual location, motor improvement measured using (UPDRS III), and postoperative stimulation parameters. Statistical analysis was performed with Review Manager 5.1.7. and OpenMeta [Analyst]. RESULTS: Three studies met inclusion criteria with a total of 247 patients. Asleep DBS was used to treat 192 (77.7 %) patients. Follow-up ranged from 6 to 48 months. Radial error was not statistically different between groups (MD -0.49 mm; 95 % CI -1.0 to 0.02; I2 = 86 %; p = 0.06), with a tendency for higher target accuracy with the asleep technique. There was no significant difference between groups in change on motor function, as measured by UPDRS III, from pre- to postoperative (MD 8.30 %; 95 % CI -4.78 to 21.37; I2 = 67 %, p = 0.2). There was a significant difference in postoperative stimulation voltage, with the asleep group requiring less voltage than the awake group (MD -0.27 V; 95 % CI -0.46 to - 0.08; I2 = 0 %; p = 0.006). CONCLUSION: Our meta-analysis indicates that asleep image-guided GPi DBS presents a statistical tendency suggesting superior target accuracy when compared with the awake standard technique. Differences in change in motor function were not statistically significant between groups.

Preventing Shift from Pneumocephalus During Deep Brain Stimulation Surgery: Don't Give Up the 'Fork in the Brain'.

Clinical vignette: We present the case of a patient who developed intra-operative pneumocephalus during left globus pallidus internus deep brain stimulation (DBS) placement for Parkinson's disease (PD). Microelectrode recording (MER) revealed that we were anterior and lateral to the intended target. Clinical dilemma: Clinically, we suspected brain shift from pneumocephalus. Removal of the guide-tube for readjustment of the brain target would have resulted in the introduction of movement resulting from brain shift and from displacement from the planned trajectory. Clinical solution: We elected to leave the guide-tube cannula in place and to pass the final DBS lead into a channel that was located posterior-medially from the center microelectrode pass. Gap in knowledge: Surgical techniques which can be employed to minimize brain shift in the operating room setting are critical for reduction in variation of the final DBS lead placement. Pneumocephalus after dural opening is one potential cause of brain shift. The recognition that the removal of a guide-tube cannula could worsen brain shift creates an opportunity for an intraoperative team to maintain the advantage of the 'fork' in the brain provided by the initial procedure's requirement of guide-tube placement.

Outcomes of Unilateral Pallidotomy in Focal and Hemidystonia Cases: A Single-Blind Cohort Study.

BACKGROUND: The role of deep brain stimulation in the treatment of dystonia has been widely documented. However, there is limited literature on the outcome of lesioning surgery in unilateral dystonia. OBJECTIVE: We restrospectively reviewed our cases of focal and hemidystonia undergoing unilateral Pallidotomy at our institute to evaluate the short-term and long-term outcome. METHODS: Patients who underwent radiofrequency lesioning of GPi for unilateral dystonia between 1999 and 2019 were retrospectively reviewed. All patients were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and Dystonia Disability Scale (DDS) preoperatively at the short term follow-up (<1 year) and at long-term follow-up (2-7.5 years). Video recordings performed at these time points were independently reviewed by a blinded movement disorders specialist. RESULTS: Eleven patients were included for analysis. The preoperative, short-term, and long-term follow-up motor BFMDRS and DDS scores were 15.5 (IQR [interquartile range]: 10.5, 23.75) and 10.5 (IQR: 6.0, 14.5); 3.0 (IQR: 1.0, 6.0, P = 0.02) and 3.0 (IQR: 3.0, 8.0, P = 0.016); and 14.25 (IQR: 4.0, 20.0, P = 0.20) and 10.5 (IQR: 2.0, 15.0, P = 0.71) respectively. For observers B, the BFMDRS scores at the same time points were 19 (IQR: 12.5, 27.0), 7.5 (IQR: 6.0, 15.0, P = 0.002), and 21 (IQR: 7.0, 22.0, P = 0.65) respectively. The improvement was statistically significant for all observations at short-term follow-up but not at long-term follow-up. CONCLUSION: Pallidotomy is effective for hemidystonia or focal dystonia in the short term. Continued benefit was seen in the longer term in some patients, whereas others worsened. Larger studies may be able to explain this in future.

Deep brain stimulation in pediatric dystonia: calls for therapeutic realism over nihilism.

PURPOSE: Pediatric dystonia (PD) has a significant negative impact on the growth and development of the child. This study was done retrospectively to analyze functional outcomes in pediatric patients with dystonia who underwent deep brain stimulation. METHODS: In this retrospective analytical study, all the patients of age less than 18 years undergoing deep brain stimulation (DBS) for dystonia between 2012 and 2020 in a single center were analyzed and their functional outcomes were measured by the Burke-Fahn-Marsden-dystonia-rating-scale (BFMDRS). RESULTS: A total of 10 pediatric patients were included with a mean age of onset, duration of disease, and age at surgery being 5.75 years, 7.36 years, and 13.11 years, respectively, with a mean follow-up of 23.22 months. The mean pre-DBS motor score was 75.44 ± 23.53 which improved significantly at 6-month and 12-month follow-up to 57.27 (p value 0.004) and 50.38 (p value < 0.001), respectively. Limbs sub-scores improved significantly at both the scheduled intervals. There was a significant improvement in disability at 1-year follow-up with significant improvement in feeding, dressing, and walking components. There was a 27.34% and 36.64% improvement in dystonia with a 17.37% and 28.86% reduction in disability at 6 months and 12 months, respectively. There was a positive correlation between the absolute reduction of the motor score and improvement in disability of the patients at 6 months (rho = 0.865, p value 0.003). CONCLUSIONS: DBS in PD has an enormous role in reducing disease burden and achieving a sustainable therapeutic goal.

PAllidal versus SubThalamic deep brain Stimulation for Cervical Dystonia (PASTS-CD): study protocol for a multicentre randomised controlled trial.

INTRODUCTION: Deep brain stimulation (DBS) has been validated as a safe and effective treatment for refractory cervical dystonia (CD). Globus pallidus internus (GPi) and subthalamic nucleus (STN) are the two main stimulating targets. However, there has been no prospective study to clarify which target is the better DBS candidate for CD. The objective of this trial is to compare directly the efficacy and safety of GPi-DBS and STN-DBS, thereby instructing the selection of DBS target in clinical practice. METHODS AND ANALYSIS: This multicentre, prospective, randomised, controlled study plans to enrol 98 refractory CD patients. Eligible CD patients will be randomly allocated to GPi-DBS group or STN-DBS group, with the DBS electrodes implanted into the posteroventral portion of GPi or the dorsolateral portion of STN, respectively. The primary outcome will be the improvement of symptomatic severity, measured by the changes in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) severity subscale and the Tsui scale at 3 months, 6 months and 12 months after surgery. The secondary outcomes include the improvement of the TWSTRS-disability subscale, TWSTRS-pain subscale, quality of life, mental and cognitive condition, as well as the differences in stimulation parameters and adverse effects. In addition, this study intends to identify certain predictors of DBS efficacy for CD. ETHICS AND DISSEMINATION: The trial has been approved by the Medical Ethics Committee of Chinese PLA General Hospital (S2022-613-01). The results of this study will be published in international peer-reviewed journals and shared in professional medical conferences. TRIAL REGISTRATION NUMBER: NCT05715138.

Deep Brain Stimulation of the Globus Pallidus Internus and Externus in Multiple System Atrophy.

BACKGROUND: Multiple system atrophy with parkinsonism (MSA-P) is a progressive condition with no effective treatment. OBJECTIVE: The aim of this study was to describe the safety and efficacy of deep brain stimulation (DBS) of globus pallidus pars interna and externa in a cohort of patients with MSA-P. METHODS: Six patients were included. Changes in Movement Disorders Society Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS III), Parkinson's Disease Questionnaire (PDQ-39) scores, and levodopa equivalent daily dose were compared before and after DBS. Electrode localization and volume tissue activation were calculated. RESULTS: DBS surgery did not result in any major adverse events or intraoperative complications. Overall, no differences in MDS-UPDRS III scores were demonstrated (55.2 ± 17.6 preoperatively compared with 67.3 ± 19.2 at 1 year after surgery), although transient improvement in mobility and dyskinesia was reported in some subjects. CONCLUSIONS: Globus pallidus pars interna and externa DBS for patients with MSA-P did not result in major complications, although it did not provide significant clinical benefit as measured by MDS-UPDRS III. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Neurosurgical management of non-spastic movement disorders.

BACKGROUND: Non-spastic movement disorders in children are common, although true epidemiologic data is difficult to ascertain. Children are more likely than adults to have hyperkinetic movement disorders defined as tics, dystonia, chorea/athetosis, or tremor. These conditions manifest from acquired or heredodegenerative etiologies and often severely limit function despite medical and surgical management paradigms. Neurosurgical management for these conditions is highlighted. METHODS: We performed a focused review of the literature by searching PubMed on 16 May 2023 using key terms related to our review. No temporal filter was applied, but only English articles were considered. We searched for the terms (("Pallidotomy"[Mesh]) OR "Rhizotomy"[Mesh]) OR "Deep Brain Stimulation"[Mesh], dystonia, children, adolescent, pediatric, globus pallidus, in combination. All articles were reviewed for inclusion in the final reference list. RESULTS: Our search terms returned 37 articles from 2004 to 2023. Articles covering deep brain stimulation were the most common (n = 34) followed by pallidotomy (n = 3); there were no articles on rhizotomy. DISCUSSION: Non-spastic movement disorders are common in children and difficult to treat. Most of these patients are referred to neurosurgery for the management of dystonia, with modern neurosurgical management including pallidotomy, rhizotomy, and deep brain stimulation. Historically, pallidotomy has been effective and may still be preferred in subpopulations presenting either in status dystonicus or with high risk for hardware complications. Superiority of DBS over pallidotomy for secondary dystonia has not been determined. Rhizotomy is an underutilized surgical tool and more study characterizing efficacy and risk profile is indicated.

Improvement of obsessive-compulsive disorder after pallidothalamic tractotomy for cervical dystonia.

A 30-year-old woman with tardive dystonia in the cervical region from long-term antipsychotic meds was treated with radiofrequency ablation of the right pallidothalamic tract in the fields of Forel. The patient showed improvement in both cervical dystonia and obsessive-compulsive disorder after the procedure, with 77.4% improvement in cervical dystonia and 86.7% improvement in obsessive-compulsive disorder. Although the treatment site in this case was intended to treat cervical dystonia, the lesion was located in the optimal stimulation network for both obsessive-compulsive disorder and cervical dystonia, suggesting that neuromodulation of this region could potentially treat both simultaneously.

Cerebellar deep brain stimulation for the treatment of movement disorders in cerebral palsy.

OBJECTIVE: Cerebral palsy (CP) represents the most common childhood physical disability that encompasses disorders of movement and posture attributed to nonprogressive disturbances that occurred in the developmental fetal or infant brain. Dyskinetic CP (DCP), the second most common type of CP after spastic forms, refers to a subset of patients in whom dystonia and choreoathetosis are the predominant motor manifestations. Most children with CP have abnormal brain MRI studies indicative of cortical and deep gray matter damage consistent with hypoxic ischemic encephalopathy, which may preclude or suggest decreased efficacy of standard deep brain stimulation (DBS) targets. The cerebellum has been posited as an attractive target for treatment of DCP because it is frequently spared from hypoxic ischemic damage and has shown promise in alleviating patient symptoms both in early work in the 1970s and in more recent case series with DBS. METHODS: The authors performed bilateral cerebellar DBS implantation, targeting the dentate nucleus (DN) and cerebellar outflow pathway, in 3 patients with DCP. Leads were connected to a pulse generator that senses local field potentials during chronic continuous DBS. The authors report their surgical methods, examples of chronic cerebellar local field potential recordings, and preliminary clinical outcomes. Motor outcomes were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale. RESULTS: Three patients 14-22 years old with DCP and MRI evidence of structural damage to the basal ganglia were offered cerebellar stimulation targeting the DN. All patients tolerated the procedure well and demonstrated improvement in subjective motor function as well as objective improvement in the Burke-Fahn-Marsden Dystonia Rating Scale movement subscale, although the range of responses was variable (19%-40%). Patients experienced subjective improvement in motor function including ease of hand movements and coordination, gait, head control, speech, decreased overflow, and diminished muscle tightness. CONCLUSIONS: DBS of the dentate nuclei in patients with DCP appears to be safe and shows preliminary evidence of clinical benefit. New chronic sensing technology may allow for determination of in vivo mechanisms of network disruption in DCP and allow for further understanding of the effects of neuromodulation on brain physiology. Larger studies with long-term follow up will be required to further elucidate the clinical benefits of this therapy. This report addresses a gap in the literature regarding the technical approach to image-based stereotactic targeting and chronic neural recording in the DN.

Stereotactic and Functional Neurosurgery Convection-Enhanced Delivery of Autologous Cerebrospinal Fluid Enhances Basal Ganglia Visualization during MRI-Guided Deep Brain Stimulation Surgery.

INTRODUCTION: The aim of this study was to determine the safety and feasibility of convection-enhanced delivery of autologous cerebrospinal fluid (CSF) for enhancing intraoperative magnetic resonance imaging (MRI) of the basal ganglia during stereotactic neurosurgery. METHODS: This pilot study was conducted in 4 patients with Parkinson's disease (PD) who underwent MRI-guided deep brain stimulation of the globus pallidus internus (GPi). CSF was obtained via lumbar puncture after general anesthesia and prior to incision. A frameless stereotaxy system was installed, and an infusion catheter was inserted to the GPi using intraoperative MRI. Infusion of autologous CSF was performed at a convective rate of 5 µL/min with a maximum volume of infusion (Vi) of 500 mL. T2-weighted MRI scans were obtained every 15 min up to a maximum of 105 min in order to calculate the volume of distribution (Vd). Safety was assessed with adverse event monitoring, and clinical outcomes were measured with changes in unmedicated UPDRS part III and PDQ-39 scores from baseline to 6 months postoperatively. RESULTS: All four infusions were safe and without adverse events. The mean unmedicated UPDRS part III and PDQ-39 scores improved by 24% and 26%, respectively. The Vd:Vi ratio ranged from 2.2 to 2.8 and peaked 45 min from the onset of infusion, which is when the borders of the GPi could generally be visualized based on T2-weighted MRI. Two patients underwent refinement of the stereotactic targeting based on infusion-enhanced images. CONCLUSIONS: The convective administration of autologous CSF to deep brain structures appears safe and feasible for enhancing intraoperative MRI during stereotactic procedures. Infusion-enhanced imaging with target-specific infusates could be developed to visualize neurochemical circuits or cellular regions that currently are not seen with anatomic/structural MRI.

Trial of Globus Pallidus Focused Ultrasound Ablation in Parkinson's Disease.

BACKGROUND: Unilateral focused ultrasound ablation of the internal segment of globus pallidus has reduced motor symptoms of Parkinson's disease in open-label studies. METHODS: We randomly assigned, in a 3:1 ratio, patients with Parkinson's disease and dyskinesias or motor fluctuations and motor impairment in the off-medication state to undergo either focused ultrasound ablation opposite the most symptomatic side of the body or a sham procedure. The primary outcome was a response at 3 months, defined as a decrease of at least 3 points from baseline either in the score on the Movement Disorders Society-Unified Parkinson's Disease Rating Scale, part III (MDS-UPDRS III), for the treated side in the off-medication state or in the score on the Unified Dyskinesia Rating Scale (UDysRS) in the on-medication state. Secondary outcomes included changes from baseline to month 3 in the scores on various parts of the MDS-UPDRS. After the 3-month blinded phase, an open-label phase lasted until 12 months. RESULTS: Of 94 patients, 69 were assigned to undergo ultrasound ablation (active treatment) and 25 to undergo the sham procedure (control); 65 patients and 22 patients, respectively, completed the primary-outcome assessment. In the active-treatment group, 45 patients (69%) had a response, as compared with 7 (32%) in the control group (difference, 37 percentage points; 95% confidence interval, 15 to 60; P = 0.003). Of the patients in the active-treatment group who had a response, 19 met the MDS-UPDRS III criterion only, 8 met the UDysRS criterion only, and 18 met both criteria. Results for secondary outcomes were generally in the same direction as those for the primary outcome. Of the 39 patients in the active-treatment group who had had a response at 3 months and who were assessed at 12 months, 30 continued to have a response. Pallidotomy-related adverse events in the active-treatment group included dysarthria, gait disturbance, loss of taste, visual disturbance, and facial weakness. CONCLUSIONS: Unilateral pallidal ultrasound ablation resulted in a higher percentage of patients who had improved motor function or reduced dyskinesia than a sham procedure over a period of 3 months but was associated with adverse events. Longer and larger trials are required to determine the effect and safety of this technique in persons with Parkinson's disease. (Funded by Insightec; ClinicalTrials.gov number, NCT03319485.).

Identifying the therapeutic zone in globus pallidus deep brain stimulation for Parkinson's disease.

OBJECTIVE: The globus pallidus internus (GPI) has been demonstrated to be an effective surgical target for deep brain stimulation (DBS) treatment in patients with medication-refractory Parkinson's disease (PD). The ability of neurosurgeons to define the area of greatest therapeutic benefit within the globus pallidus (GP) may improve clinical outcomes in these patients. The objective of this study was to determine the best DBS therapeutic implantation site within the GP for effective treatment in PD patients. METHODS: The authors performed a retrospective review of 56 patients who underwent bilateral GP DBS implantation at their institution during the period from January 2015 to January 2020. Each implanted contact was anatomically localized. Patients were followed for stimulation programming for at least 6 months. The authors reviewed preoperative and 6-month postsurgery clinical outcomes based on data from the Unified Parkinson's Disease Rating Scale Part III (UPDRS III), dyskinesia scores, and levodopa equivalent daily dose (LEDD). RESULTS: Of the 112 leads implanted, the therapeutic cathode was most frequently located in the lamina between the GPI external segment (GPIe) and the GP externus (GPE) (n = 40). Other common locations included the GPE (n = 24), the GPIe (n = 15), and the lamina between the GPI internal segment (GPIi) and the GPIe (n = 14). In the majority of patients (73%) a monopolar programming configuration was used. At 6 months postsurgery, UPDRS III off medications (OFF) and on stimulation (ON) scores significantly improved (z = -4.02, p < 0.001), as did postsurgery dyskinesia ON scores (z = -4.08, p < 0.001) and postsurgery LEDD (z = -4.7, p < 0.001). CONCLUSIONS: Though the ventral GP (pallidotomy target) has been a commonly used target for GP DBS, a more dorsolateral target may be more effective for neuromodulation strategies. The assessment of therapeutic contact locations performed in this study showed that the lamina between GPI and GPE used in most patients is the optimal central stimulation target. This information should improve preoperative GP targeting.

Micro lesion effect of pallidal deep­brain stimulation for meige syndrome.

To analyse the microlesion effect (MLE) in the globus pallidus interna (GPi) of deep brain stimulation (DBS) in patients with Meige syndrome. Thirty-two patients with primary Meige syndrome who underwent GPi-DBS in this study. Burke-Fahn-Marsden Dystonia Rating Scale scores (BFMDRS-M) were obtained for the evaluation of clinical symptoms at 3 days before DBS (baseline), 24 h after DBS surgery, once weekly for 1 month until electrical stimulation, 6 months postoperatively and 12 months after surgery. Twenty-seven patients had MLE after GPi-DBS. The mean time of BFMDRS-M scores maximal improvement from MLE was 35.9 h postoperatively (range, 24-48 h), and the mean scores improved by 49.35 ± 18.16%. At 12 months after surgery, the mean BFMDRS-M scores improved by 50.28 ± 29.70%. There was a positive correlation between the magnitude of MLE and the motor score at 12 months after GPi-DBS (R2 = 0.335, p < 0.05). However, there was no correlation between the duration of MLE and DBS improvement. Most Meige syndrome patients who underwent GPi-DBS and had MLE benefited from MLE. For Meige syndrome, MLE might be a predictive factor for patient clinical symptom improvement from DBS.

Clinical factors and dopamine transporter availability for the prediction of outcomes after globus pallidus deep brain stimulation in Parkinson's disease.

We aimed to investigate the predictive value of preoperative clinical factors and dopamine transporter imaging for outcomes after globus pallidus interna (GPi) deep brain stimulation (DBS) in patients with advanced Parkinson's disease (PD). Thirty-one patients with PD who received bilateral GPi DBS were included. The patients underwent preoperative [18F] FP-CIT positron emission tomography before DBS surgery. The Unified Parkinson's Disease Rating Scale (UPDRS) were used to assess outcomes 12 months after DBS. Univariate and multivariate linear regression analysis were performed to investigate the association between clinical variables including sex, age at onset of PD, disease duration, cognitive status, preoperative motor severity, levodopa responsiveness, daily dose of dopaminergic medication, and dopamine transporter availability in the striatum and outcomes after GPi DBS. Younger age at onset of PD was associated with greater DBS motor responsiveness and lower postoperative UPDRS III score. Greater levodopa responsiveness, lower preoperative UPDRS III score and lower striatal dopamine transporter availability were associated with lower postoperative UPDRS III score. Younger age at onset was also associated with greater decrease in UPDRS IV score and dyskinesia score after GPi DBS. Our results provide useful information to select DBS candidates and predict therapeutic outcomes after GPi DBS in advanced PD.

Long-Term Outcomes of Idiopathic and Acquired Dystonia After Pallidal Deep Brain Stimulation: A Case Series.

BACKGROUND: Among dystonia patients receiving globus pallidus internus (GPi) deep brain stimulation (DBS), long-term outcomes remain to be established. To report the long-term outcomes of GPi DBS in a patient cohort with idiopathic and acquired dystonia. METHODS: In this long-term follow-up cohort, there were 4 patients with idiopathic dystonia and 2 patients with acquired dystonia. The Burke-Fahn-Marsden Dystonia Rating Scale was used to evaluate 6 consecutive patients preoperatively and at 6 months, 12 months, and the last follow-up. The relationship between etiology and clinical improvement was analyzed. Stimulation parameters were evaluated for similarities and differences among these patients. RESULTS: The mean follow-up of our cohort was 65.3 months (median 40.5 months). The average improvement in the Burke-Fahn-Marsden Dystonia Rating Scale (mean ± SEM) were 56% ± 7.6, 67% ± 6.8 and 66% ± 9.7 at 6 months, 12 months, and the last follow-up, respectively. There was greater improvement during the long-term follow-up in the 4 patients with idiopathic dystonia than in the 2 patients with acquired dystonia. The 2 most ventral electrodes (contact 0 and 1) were activated in all 11 leads in this cohort. The average stimulation intensity, pulse width and frequency were 2.0 ± 0.24 mA, 252 ± 43 µs, and 99 ± 6.0 Hz, respectively. CONCLUSIONS: Isolated dystonia, either monogenic or idiopathic, usually responds better to GPi DBS than to acquired dystonia. Selection of patients by dystonia etiology, accurate placement of DBS leads in GPi targets, and proper stimulation programming are crucial to achieve better long-term outcomes.

Deep brain stimulation in dystonia: factors contributing to variability in outcome in short and long term follow-up.

PURPOSE OF REVIEW: Deep brain stimulation (DBS) is currently the most effective treatment for medically refractory dystonia with globus pallidus internus (GPi) usually the preferred target. Despite the overall success of DBS in dystonia, there remains variability in treatment outcome in both short and long-term follow-up, due to various factors. Factors contributing to variability in outcome comprise 'Dystonia Related' including dystonia classification, semiology, duration, body distribution, orthopaedic deformity, aetiology and genetic cause. The majority of these factors are identifiable from clinical assessment, brain MRI and genetic testing, and therefore merit careful preoperative consideration. 'DBS related' factors include brain target, accuracy of lead placement, stimulation parameters, time allowed for response, neurostimulation technology employed and DBS induced side-effects. In this review, factors contributing to variability in short and long-term dystonia DBS outcome are reviewed and discussed. RECENT FINDINGS: The recognition of differential DBS benefit in monogenic dystonia, increasing experience with subthalamic nucleus (STN) DBS and in DBS for Meige syndrome, elucidation of DBS side effects and novel neurophysiological and imaging techniques to assist in predicting clinical outcome. SUMMARY: Improved understanding of factors contributing to variability of DBS outcome in dystonia may assist in patient selection and predicting surgical outcomes.

Unilateral Campotomy of Forel for Acquired Hemidystonia: An Open-Label Clinical Trial.

BACKGROUND: Hemidystonia (HD) is characterized by unilateral involuntary torsion movements and fixed postures of the limbs and face. It often develops after deleterious neuroplastic changes secondary to injuries to the brain. This condition usually responds poorly to medical treatment, and deep brain stimulation often yields unsatisfactory results. We propose this study based on encouraging results from case reports of patients with HD treated by ablative procedures in the subthalamic region. OBJECTIVE: To compare the efficacy of stereotactic-guided radiofrequency lesioning of the subthalamic area vs available medical treatment in patients suffering from acquired HD. METHODS: This is an open-label study in patients with secondary HD allocated according to their treatment choice, either surgical or medical treatment; both groups were followed for one year. Patients assigned in the surgical group underwent unilateral campotomy of Forel. The efficacy was assessed using the Unified Dystonia Rating Scale, Fahn-Marsden Dystonia Scale, Arm Dystonia Disability Scale, and SF-36 questionnaire scores. RESULTS: Patients in the surgical group experienced significant improvement in the Unified Dystonia Rating Scale, Fahn-Marsden Dystonia Scale, and Arm Dystonia Disability Scale (39%, 35%, and 15%, respectively) 1 year after the surgery, with positive reflex in quality-of-life measures, such as bodily pain and role-emotional process. Patients kept on medical treatment did not experience significant changes during the follow-up. No infections were recorded, and no neurological adverse events were associated with either intervention. CONCLUSION: The unilateral stereotaxy-guided ablation of Forel H1 and H2 fields significantly improved in patients with HD compared with optimized clinical treatment.

Bilateral subthalamic nucleus deep brain stimulation for refractory isolated cervical dystonia.

Subthalamic nucleus (STN) deep brain stimulation (DBS) has been proven to be an alternative target choice for refractory isolated cervical dystonia (CD). However, assessments of its short and long-term safety, efficacy, and sustained effectiveness have been limited to few reports. Here, we evaluated nine consecutive refractory isolated CD patients who underwent bilateral STN DBS and accepted to short and long-term follow-up in this retrospective study. Seven time points were used to see the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores (pre-operation [baseline], 1, 3, 6, 12, 24 months post-operation and last follow-up) to assess improvement of dystonic symptoms. The 36-item Short-Form General Health Survey (SF-36) scores obtained at pre-operation and last follow-up to assess the changes in quality of life. All patients tolerated surgery well and acquired observable clinical benefits from STN DBS therapy. All patients achieved a considerable improvement in quality of life at the last follow-up. The hardware-related adverse events can be tolerated and the stimulation-related adverse events can be ameliorated by programming. Our data support the idea that bilateral STN DBS is a safety and effective method for the treatment of refractory isolated CD, with persistent and remarkable improvement in both movement and quality of life.