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Background: Deep Brain Stimulation (DBS) is an established treatment option for refractory dystonia, but the improvement among the patients is variable., Objective: To describe the outcomes of DBS of the subthalamic region (STN) in dystonic patients and to determine whether the volume of tissue activated (VTA) inside the STN or the structural connectivity between the area stimulated and different regions of the brain are associated with dystonia improvement., Methods: The response to DBS was measured by the Burke-Fahn-Marsden Dystonia Rating Scale (BFM) before and 7 months after surgery in patients with generalized isolated dystonia of inherited/idiopathic etiology. The sum of the two overlapping STN volumes from both hemispheres was correlated with the change in BFM scores to assess whether the area stimulated inside the STN affects the clinical outcome. Structural connectivity estimates between the VTA (of each patient) and different brain regions were computed using a normative connectome taken from healthy subjects., Results: Five patients were included. The baseline BFM motor and disability subscores were 78.30 ± 13.55 (62.00-98.00) and 20.60 ± 7.80 (13.00-32.00), respectively. Patients improved dystonic symptoms, though differently. No relationships were found between the VTA inside the STN and the BFM improvement after surgery ( p  = 0.463). However, the connectivity between the VTA and the cerebellum structurally correlated with dystonia improvement ( p  = 0.003)., Conclusions: These data suggest that the volume of the stimulated STN does not explain the variance in outcomes in dystonia. Still, the connectivity pattern between the region stimulated and the cerebellum is linked to outcomes of patients., Competing Interests: The authors have no conflict of interests to declare., (Academia Brasileira de Neurologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution 4.0 International License, permitting copying and reproduction so long as the original work is given appropriate credit (https://creativecommons.org/licenses/by/4.0/).)

Background: Dystonia is characterized by sustained or intermittent muscle contractions, leading to abnormal posturing and twisting movements. In pediatric patients, dystonia often negatively influences quality of life. Pharmacological treatment for dystonia is often inadequate and causes adverse effects. Deep brain stimulation (DBS) appears to be a valid therapeutic option for pharmacoresistant dystonia in children., Methods: To illustrate the current clinical practice, we hereby describe two pediatric cases of monogenetic movement disorders presenting with dystonia and treated with DBS. We provide a literature review of similar previously described cases and on different clinical aspects of DBS in pediatric dystonia., Results: The first patient, a 6-year-old girl with severe dystonia, chorea, and myoclonus due to an ADCY5 gene mutation, received DBS in an elective setting. The second patient, an 8-year-old boy with GNAO1 -related dystonia and chorea, underwent emergency DBS due to a pharmacoresistant status dystonicus. A significant amelioration of motor symptoms (65% on the Burke-Fahn-Marsden Dystonia Rating Scale) was observed postoperatively in the first patient and her personal therapeutic goals were achieved. DBS was previously reported in five patients with ADCY5 -related movement disorders, of which three showed objective improvement. Emergency DBS in our second patient resulted in the successful termination of his GNAO1 -related status dystonicus, this being the eighth case reported in the literature., Conclusion: DBS can be effective in monogenetic pediatric dystonia and should be considered early in the disease course. To better evaluate the effects of DBS on patients' functioning, patient-centered therapeutic goals should be discussed in a multidisciplinary approach., Competing Interests: M.B. was awarded the TKI-PPP grant in 2021. A.I.B. is the chair of the board of the Dutch Academy of Childhood Disability. J.M.D. was awarded the Netherlands Organization for Health Research and Development grant and a Medtronic grant. J.M.D. is the president of the Netherlands workgroup for Movement Disorders. P.R.S. was awarded consulting fees from Boston Scientific, Medtronic, Elekta and lecture fees from Boston Scientific and Elekta. P.R.S. is the treasurer of the European Society for Stereotactic and Functional Neurosurgery, an associate editor of the Journal of Parkinson's Disease and is in the advisory board of Boston Scientific and Insightec., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

Aim: To establish the prevalence of dystonic pain in children and their response to deep brain stimulation (DBS)., Method: Dystonic pain was assessed in a cohort of 140 children, 71 males and 69 females, median age 11 years 11 months (range 3y-19y 1mo), undergoing DBS in our centre over a period of 10 years. The cohort was divided into aetiological dystonia groups: 1a, inherited; 1b, heredodegenerative; 2, acquired; and 3, idiopathic. Motor responses were measured with the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS)., Results: Dystonic pain was identified in 63 (45%) patients, 38% of whom had a diagnosis of cerebral palsy (CP). Dystonic pain improved in 90% of children and in all aetiological subgroups 1 year after DBS, while the BFMDRS motor score improved in 70%. Statistically significant improvement (p<0.01) was noted for the whole cohort on the Numerical Pain Rating Scale (n=27), Paediatric Pain Profile (n=17), and Caregivers Priorities and Child Health Index of Life with Disabilities questionnaire (n=48). There was reduction of pain severity, frequency, and analgesia requirement. Findings were similar for the whole cohort and aetiological subgroups other than the inherited heredodegenerative group where the improvement did not reach statistical significance., Interpretation: Dystonic pain is frequent in children with dystonia, including those with CP, who undergo DBS; this can be an important, realizable goal of surgery irrespective of aetiology. We encourage the use of multimodal approach in pain research to reduce the risk of bias., (© 2020 Mac Keith Press.)

Background: Deep brain stimulation (DBS) is a treatment modality increasingly utilized in the management of neurological and psychiatric conditions. Neurosurgical technical considerations and contraindications have yet to be thoroughly characterized in the literature. The patient population for DBS includes many elderly patients with multiple comorbidities who require treatments and investigations that expose them to electromagnetic fields of varying strengths and durations, including other implanted electromodulatory devices., Objective: To determine if clinically significant interference arises between DBS and cardiac pacemaker systems., Methods: Here we audited 8 patients, mean age 72, with cardiac pacemakers and DBS implanted from 2007 to 2015. We investigated details of their neurological and electrocardiological treatment and progress and sought evidence for interference between the two systems., Results: We found no evidence of DBS dysfunction, and only one case of abnormal pacemaker interrogation 2 yr post-DBS implantation was found, which was thought to be secondary to a medication issue rather than neuromodulation interference., Conclusion: Our research reassures the clinician that pacemakers and DBS systems do not appear to affect one another and provides guidance on minimizing possibility of this., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Introduction:  A 28-year-old man presented with a history of sensorineural deafness since early childhood treated with bilateral cochlear implants (CIs). He showed signs of debilitating dystonia that had been present since puberty. Dystonic symptoms, especially a protrusion of the tongue and bilateral hand tremor, had not responded to botulinum toxin therapy. We diagnosed Mohr-Tranebjaerg syndrome (MTS)., Methods and Material:  Deep brain stimulation (DBS) of the bilateral globus pallidus internus was performed predominantly with stereotaxic computed tomography angiography guidance under general anesthesia. Electrophysiology was used to identify the target regions and to guide DBS electrode placement., Results:  In the immediate postoperative course and stimulation, the patient showed marked improvement of facial, extremity, and cervical dystonia. More than 2 years after implantation, his dystonic symptoms had dramatically improved by 82%., Discussion:  MTS is a rare genetic disorder leading to sensorineural deafness, dystonia, and other symptoms. The use of DBS for the dystonia in MTS was previously described but not in the presence of bilateral CIs., Conclusion:  DBS in MTS may be a viable option to treat debilitating dystonic symptoms. We describe successful DBS surgery, despite the presence of bilateral CIs, and stimulation therapy over 2 years., Competing Interests: None., (Georg Thieme Verlag KG Stuttgart · New York.)

Introduction: Deep brain stimulation (DBS) has emerged as an effective treatment in medically intractable dystonia, with the globus pallidus internus (GPi) being most frequently targeted. Non-motor symptoms, including pain and psychiatric, cognitive and sleep disturbances, are increasingly recognized as important determinants of disease burden in dystonia patients. We reviewed non-motor outcomes of DBS in dystonia, focusing on GPi-DBS., Methods: A systematic literature search of Pubmed and Embase was performed according to the PRISMA guidelines., Results: Fifty-two studies were included. GPi-DBS reduced pain related to dystonia. No major effects on anxiety, mood, and cognition were found. In contrast to motor outcome, non-motor outcome seems more independent of the etiology of dystonia. However, the impact of potential confounders (e.g. patient factors, changes in pharmacological treatment) is unclear., Conclusion: Despite the growing interest in non-motor symptoms in dystonia, DBS studies still focus primarily on motor outcome. We recommend systematic evaluation of both non-motor and motor features before and after DBS interventions to improve quality of life and management of patients with dystonia., (Copyright © 2018. Published by Elsevier Ltd.)

Background: Little is known about the quality of life of people with dystonia and DBS beyond 5 years. The objectives of this study were (1) to examine the long-term quality-of-life outcomes in a large cohort of people with dystonia and DBS, (2) to determine the incidence of stimulation-induced parkinsonism, and (3) to elucidate the potential long-term cognitive impact of DBS in this cohort., Methods: Fifty-four subjects with dystonia and DBS for more than 5 years were contacted via social media and were offered to complete a quality-of-life survey comparing current-day life and life prior to DBS. The primary study outcomes were the Short Form survey, a parkinsonian symptoms questionnaire, the Telephone Montreal Cognitive Assessment, and the Measurement of Every Day Cognition., Results: Thirty-seven of 54 subjects consented to the study. Average age was 39.7 ± 16.6 years, 16 were female, and 23 were DYT1+. Average time from implantation was 10.5 years. Average total Short Form survey scores improved, from 43.7 pre-DBS to 69.5 current day (P < 0.0005). Mean total self-reported parkinsonian symptom score was 13.8 ± 14.7, with worsening balance and hypophonia the most common. Average Telephone Montreal Cognitive Assessment was 20.1 ± 1.6, with 3 of 29 scores (10.3%) in the impaired range (score of 18 or less). Average total Every Day Cognition score was 1.25 ± 0.35, with 3 subjects (10.3%) scoring in the range of impaired cognition (>1.81)., Conclusions: DBS for dystonia results in long-term quality-of-life improvements that persist on average 10 years or more after surgery. The prevalence of stimulation-induced parkinsonism and cognitive impairment is low. © 2018 International Parkinson and Movement Disorder Society., (© 2018 International Parkinson and Movement Disorder Society.)

Clinical Vignette: A 64-year-old female with essential tremor (ET) presents for evaluation of deep brain stimulation (DBS) candidacy. Examination revealed subtle dystonic features as well as a disabling postural-action tremor., Clinical Dilemma: Can dystonia occur in the setting of the diagnosis of ET and can its presence alter DBS target selection?, Clinical Solution: Unilateral DBS implantation of the ventralis intermedius (Vim) led to improvement in both tremor and dystonic posturing., Gap in Knowledge: Case reports of DBS in dystonic tremor suggest Vim, globus pallidus internus (GPi), and subthalamic targets may all be effective, to varying degrees, in improving both tremor and dystonia. More rigorous studies are needed to identify the optimal target(s)., Expert Commentary: This case underscores the limited evidence available to guide a clinician's choice of DBS targets in patients with ET and dystonia. The severity of the dystonia and the presence of more generalized dystonia may alter the thinking about optimal targeting. Vim, GPi, and subthalamic targets appear potentially acceptable options, though Vim is usually the first target attempted when postural-action tremor is the chief complaint. Occasionally, a second rescue DBS lead may be necessary., Competing Interests: Funding: None. Conflict of Interests: The authors report no conflict of interest. Ethics Statement: All patients that appear on video have provided written informed consent; authorization for the videotaping and for publication of the videotape was provided.

Case: An adolescent girl presented with an atypical scoliotic curve, pelvic obliquity, back pain, and lower-extremity paresthesias. A workup revealed generalized primary torsion dystonia. The condition was refractory to medical treatment and necessitated implantation of a deep brain stimulator. The scoliosis required operative correction, and the patient underwent posterior spinal arthrodesis with hook-rod instrumentation, which resulted in successful correction through 7 years of follow-up., Conclusion: The differential diagnosis for adolescent scoliosis should include dystonia as a potential cause, especially when a patient presents with muscular contractures, an atypical scoliotic curve, pelvic obliquity, or changing curve characteristics.

Six cases of dystonic tremor were treated with the Vercise TM deep brain stimulation(DBS)system, which has the multiple independent current control(MICC)technology. The mean preoperative score of Burke-Fahn-Marsden dystonia rating scale was 16.2±9.4, which was reduced to 6.1±4.6 at 5 months postoperatively. A 65-year-old male presented an intractable dystonic tremor of the jaw, neck, and shoulders due to tardive syndrome. He experienced the successful tremor relief after unipolar DBS in the globus pallidus internus(GPi)with Vercise TM but complained of dysarthria. Steering the current ventrally induced nausea without alleviating dysarthria, while steering the current dorsally alleviated dysarthria but a further dorsal current induced mandibular dyskinesia. The current steering with MICC enabled the simulation field in GPi with successful balance, maximizing tremor suppression, and minimizing the adverse effects. In a second case, 61-year-old male in whom cervical dystonia with rotatory tremor had been successfully treated with interleaving stimulation of GPi-DBS had needed to repeat the replacement of a non-rechargeable pulse generator in only 15-month interval. After the substitution of Vercise TM , the interleaving stimulation of 9.5mA in total was replaced by 8.5mA with the current steering of MICC, while the patient's symptomatic control was unchanged. The microlesion effects after lead implantation are unclear and therapeutic effects are often delayed in cases of dystonia;therefore, the submaximal stimulation intensities must be frequently applied in the early phase following the implantation of DBS. A fine current steering of Vercise TM DBS is very useful in both, the early and late phases of GPi-DBS for dystonic syndrome.

SEE MOLL AND ENGEL DOI101093/AWW308 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Brain regions dynamically engage and disengage with one another to execute everyday actions from movement to decision making. Pathologies such as Parkinson's disease and tremor emerge when brain regions controlling movement cannot readily decouple, compromising motor function. Here, we propose a novel stimulation strategy that selectively regulates neural synchrony through phase-specific stimulation. We demonstrate for the first time the therapeutic potential of such a stimulation strategy for the treatment of patients with pathological tremor. Symptom suppression is achieved by delivering stimulation to the ventrolateral thalamus, timed according to the patient's tremor rhythm. Sustained locking of deep brain stimulation to a particular phase of tremor afforded clinically significant tremor relief (up to 87% tremor suppression) in selected patients with essential tremor despite delivering less than half the energy of conventional high frequency stimulation. Phase-specific stimulation efficacy depended on the resonant characteristics of the underlying tremor network. Selective regulation of neural synchrony through phase-locked stimulation has the potential to both increase the efficiency of therapy and to minimize stimulation-induced side effects., (© The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.)

Objectives: Dystonic tremor (DT) is defined as a postural/kinetic tremor occurring in the body region affected by dystonia. DT is typically characterized by focal tremors with irregular amplitudes and variable frequencies typically below 7Hz. Pharmacological treatment is generally unsuccessful and guidelines for deep brain stimulation (DBS) targeting and indications are scarce. In this article, we present the outcome and neurophysiologic data of two patients with refractory, focal limb DT treated with Globus Pallidus interna (Gpi) DBS and critically review the current literature regarding surgical treatment of DT discussing stereotactic targets and treatment considerations., Patients and Methods: A search of literature concerning treatment of DT was conducted. Additionally, Gpi DBS was performed in two patients with DT and microelectrode recordings for multi unit analysis (MUAs) and local field potentials (LFPs) were obtained., Results: The mean percentage improvement in tremor severity was 80.5% at 3 years follow up. MUAs and LFPs did not show significant differences in DT patients compared with other forms of dystonia or PD except for higher interspikes bursting indices. LFP recordings in DT demonstrated high power at low frequencies with action (<3.5Hz)., Conclusions: Gpi DBS is an effective treatment in patients with focal limb DT without associated generalized dystonia. Intraoperative neurophysiologic findings suggest that DT is part of phenotypic motor manifestations in dystonia., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has been established as an effective and safe treatment for dystonia. In general, side effects are rare, but there is increasing evidence that GPi DBS in dystonia can induce hypokinetic symptoms like micrographia or freezing of gait. We aimed to evaluate and quantify possible changes of gait following bilateral chronic GPi DBS for dystonia by computerized gait analyses., Methods: We prospectively performed computerized gait analysis in ten consecutive patients (mean age 57.8+/-14.3 years) with segmental dystonia but without involvement of lower trunk or legs who were treated with bilateral GPi DBS. Using pressure sensitive insoles, several parameters were measured preoperatively (pre-OP) and at a median of 7 months postoperatively., Results: The mean step length significantly decreased from 60.0+/-6.9cm pre-OP to 54.3+/-6.4cm with GPi DBS (p<0.01). Due to only small changes of walking distance and gait velocity, the cadence correspondingly increased from 105.6+/-9.2 steps/min to 111.3+/-11.4 steps/min (p<0.05). More importantly, the variance of several gait parameters significantly decreased postoperatively., Conclusions: In patients with segmental dystonia, chronic DBS of the posteroventral lateral GPi is associated with only mild hypokinesia of gait, but with a relevant decrease in gait variability. Given other recently reported hypokinetic effects of GPi DBS for dystonia and recent results of electrophysiological coherence studies, these findings support the hypothesis of a general alteration of neuronal activity in striato-pallido-thalamo-cortical motor pathways following chronic stimulation of the posteroventral lateral GPi., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: The most common anesthetic technique for patients undergoing insertion of deep brain stimulators (DBS) is local anesthesia with or without conscious sedation as this facilitates intraoperative microelectrode recordings (MERs) for target localization. However, general anesthesia (GA) may be needed in some of the patients especially those with dystonia. The purpose of our study was to determine the effects of GA on MERs from pallidal neurons in patients with dystonia undergoing DBS implantation surgery., Methods: After IRB approval, we retrospectively reviewed the medical records of all patients who had insertion of DBS from January 2009 to December 2013. Data collected and analyzed included demographics, indications for DBS, targets of insertion, MER, and anesthetic management. From the records we identified patients with dystonia who received GA for DBS insertion. We then compared the MER data under GA with the data from patients who had surgery under local anesthesia only during the same time period. Because of the small sample size, the effects of various anesthetic regiments on MER and localization of target nuclei were compared qualitatively., Results: Of the 435 patients who underwent DBS insertion during the study period, 20 (4.3%) patients had GA for the procedure. Dystonia was the most common indication for GA (16/20 patients, 80%). Good-quality MER data obtained from 10 patients with dystonia under GA was compared with 8 patients who had no sedation for the procedure. Administration of GA made target localization difficult due to suppression of both spontaneous and evoked neuronal discharges from internal globus pallidus. Although not studied systematically, propofol (>100 mcg/kg/min) seemed to suppress pallidal discharges more than GA with a lower dose of propofol (<75 mcg/kg/min), remifentanil, and 0.2% to 0.4% end-tidal sevoflurane or desflurane., Conclusions: Our retrospective review suggests that there was a difference in spontaneous and evoked neuronal discharges with MER performed under GA compared with no sedation. MER recordings during GA appeared most robust during a combination of anesthetics including low-dose propofol infusion, remifentanil, and a low concentration of either sevoflurane or desflurane. Our findings can inform a power analysis to determine the sample size that would be required to prospectively test the hypothesis that there is a difference in spontaneous and evoked neuronal discharges with MER performed under GA compared with no sedation.

Background: Pallidal deep brain stimulation (GPi-DBS) effectively ameliorates idiopathic dystonia, although approximately 15% of patients respond insufficiently. Although various thalamic and subthalamic targets have been suggested for dystonic tremor, no systematic studies have been published on thalamic DBS in dystonic tremor. We assessed the effect of thalamic/subthalamic area DBS (Th-DBS) on dystonic head tremor and dystonia in a single-blind design., Methods: Dystonic head tremor and dystonia before and 3 months after surgery were quantified via blinded video-ratings using the Fahn-Tolosa-Marin-Tremor-Scale and the Burke-Fahn-Marsden-Dystonia-Rating-Scale in seven patients with idiopathic cervical or segmental dystonia, dystonic head tremor, and bilateral Th-DBS. Pain, side effects, adverse events, and stimulation parameters were assessed., Results: Th-DBS improved dystonic tremor and dystonia (P < 0.05; 57.1% and 70.4%, respectively). Head tremor amplitude and pain were also improved (P < 0.05; 77.5% and 90.0%, respectively). Side effects included dysarthria, gait disturbance, slowness of movement, and weight gain., Conclusion: Dystonic head tremor and dystonia can be improved with Th-DBS., (© 2014 International Parkinson and Movement Disorder Society.)

We investigated the effect of pallidal deep brain stimulation (GPi-DBS) in dystonia on cognition, mood, and quality of life and also assessed if DYT1 gene status influenced cognitive outcome following GPi-DBS. Fourteen patients with primary generalized dystonia (PGD) were assessed, measuring their estimated premorbid and current IQ, memory for words and faces, and working memory, language, executive function, and sustained attention, one month before and one year or more after surgery. Changes in mood and behaviour and quality of life were also assessed. There was a significant improvement of dystonia with GPi-DBS (69 % improvement in Burke-Fahn-Marsden score, p < 0.0001). Performance on five cognitive tests either improved or declined at post-surgical follow-up. Calculation of a reliable change index suggested that deterioration in sustained attention on the PASAT was the only reliable change (worse after surgery) in cognition with GPi-DBS. DYT1 gene status did not influence cognitive outcome following GPi-DBS. Depression, anxiety and apathy were not significantly altered, and ratings of health status on the EQ5D remained unchanged. In our sample, GPi-DBS was only associated with an isolated deficit on a test of sustained attention, confirming that GPi-DBS in PGD is clinically effective and safe, without adverse effects on the main domains of cognitive function. The dissociation between GPi-DBS improving dystonia, but not having a significant positive impact on the patients' QoL, warrants further investigation.

The few controlled studies that have been carried out have shown that bilateral internal globus pallidum stimulation is a safe and long-term effective treatment for hyperkinetic disorders. However, most recent published data on deep brain stimulation (DBS) for dystonia, applied to different targets and patients, are still mainly from uncontrolled case reports (especially for secondary dystonia). This precludes clear determination of the efficacy of this procedure and the choice of the 'good' target for the 'good' patient. We performed a literature analysis on DBS for dystonia according to the expected outcome. We separated those with good evidence of favourable outcome from those with less predictable outcome. In the former group, we review the main results for primary dystonia (generalised/focal) and highlight recent data on myoclonus-dystonia and tardive dystonia (as they share, with primary dystonia, a marked beneficial effect from pallidal stimulation with good risk/benefit ratio). In the latter group, poor or variable results have been obtained for secondary dystonia (with a focus on heredodegenerative and metabolic disorders). From this overview, the main results and limits for each subgroup of patients that may help in the selection of dystonic patients who will benefit from DBS are discussed.

Background: Childhood dystonia can severely impact upper limb function. Deep brain stimulation (DBS) has been shown to be effective in reducing dystonic symptoms in childhood. Functional recovery following DBS is however not well understood., Aims: To explore changes in upper limb function following DBS in paediatric dystonia., Methods: Upper limb outcomes, using the Melbourne Assessment of Unilateral Upper Limb Function, are reported in 20 cases of childhood dystonia (unilateral n = 1, four limb n = 19) at 6 and 12 months following DBS., Results: Improvement in at least in one upper limb was seen in the majority of cases (n = 17, 85%) at 12 months following DBS. Deterioration of scores in both upper limbs was seen in 3 children with progressive disorders. Grouping the children aetiologically, a significant improvement in the dominant hand was obtained for the primary dystonia/dystonia-plus group at both six (p = 0.018) and twelve months (p = 0.012). In secondary dystonia due to a static disorder, improvement was also seen at 6 (p = 0.043) and 12 months (p = 0.046) in the non-dominant hand. No significant change was found in the group of children with progressive disorders., Conclusions: DBS has the potential to alter upper limb function in children with primary and secondary dystonia. The dominant hand improved most in children with primary dystonias, with greater improvement in the non-dominant hand in secondary-static cases., (Copyright © 2013 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)

Dystonic head tremor (DHT) is characterized by head tremor associated with cervical dystonia (CD). Deep brain stimulation (DBS) can be considered when local treatment with botulinum toxin or oral medication has failed. However, there is lack of data regarding the optimal target structure for surgery in DHT.DBS of the ventrolateral (VL) thalamus is an established treatment option for medically refractory tremor. Tremor suppression is described as being most effective when stimulating at the inferior thalamic base and within the posterior subthalamic area (PSA). Moreover, there is surgical evidence from the pre-DBS era that both lesions and high-frequency stimulation of the PSA improve CD. Based on these observations, we performed DBS in three patients with DHT, placing the proximal contacts of the electrodes into the inferior base of VL thalamic nuclei and the distal contacts into the adjacent PSA. Chronic stimulation improved not only head tremor but also CD. These findings suggest that DBS at the base of VL thalamus and the adjacent PSA should undergo further investigation as a potential target for patients with DHT.

The authors report a case of bilateral globus pallidus internus (GPi) stimulation for treatment of medically intractable isolated lower limb dystonia. The 14-year-old girl developed dystonic movements in her left lower limb. At the age of 17, the patient was handicapped by dystonic movements in her lower limbs, and became wheelchair-bound. Pharmacological therapy and botulinum toxin injection resulted in transient and modest benefit. Moreover, the patient was diagnosed with histologically proven coeliac disease and Langerhans cell histiocytosis. Genetic testing revealed the presence of DYT-1 mutation. The 17-year-old girl underwent bilateral implantation of deep brain stimulation leads. Bilateral GPi stimulation resulted in remarkable improvement of phasic dystonic movements, and dystonic posture of lower limbs. Over 2 years postoperative follow-up, the patient is able to walk independently. Bilateral GPi stimulation appears to be an effective treatment modality for isolated lower limb dystonia.

Camptocormia, or "bent spine syndrome", may occur in various movement disorders such as primary dystonia or idiopathic Parkinson's disease (PD). Although deep brain stimulation (DBS) is an established treatment in refractory primary dystonia and advanced PD, few data are available on the effect of DBS on camptocormia comparing these two conditions. Seven patients (4 with dystonia, 3 with PD; mean age 60.3 years at surgery, range 39-73 years) with camptocormia were included in the study. Five patients underwent bilateral GPi DBS and two patients underwent bilateral STN DBS guided by CT-stereotactic surgery and microelectrode recording. Pre- and postoperative motor assessment included the BFM in the dystonia patients and the UPDRS in the PD patients. Severity of camptocormia was assessed by the BFM subscore for the trunk at the last available follow-up at a mean of 17.3 months (range 9-36 months). There were no surgical complications. In the four patients with dystonia there was a mean improvement of 53% in the BFM motor score (range 41-79%) and of 63% (range 50-67%) in the BFM subscore for the trunk at the last available follow-up (mean 14.3 months, range 9-18 months). In the three patients with camptocormia in PD who underwent bilateral STN DBS (2 patients) or pallidal DBS (1 patient), the PD symptoms improved markedly (mean improvement in the UPDRS motor subscore stimulation on/medication off 55%, range 49-61%), but there was no or only mild improvement of camptocormia in the two patients who underwent STN DBS, and only moderate improvement in the patient with GPi DBS at the last available follow-up (mean 21 months, range 12-36 months). GPi DBS is an effective treatment for camptocormia in dystonia. The response of camptocormia to chronic STN or GPi DBS in PD is more heterogenous. The latter may be due to a variety of causes and needs further clarification.

We present the pre to post bilateral globus pallidus interna (GPi) deep brain stimulation neuropsychological profiles of a 69-year-old patient with a 12-year history of X-linked dystonia-Parkinsonism (XDP). Pre-operative cognitive function was impaired in almost all domains and this impaired performance was not dependent on his medications. Following DBS, changes in neuropsychological functioning were examined using Reliable Change Indices and standardized z-score comparisons. Results showed reductions in processing speed in the context of stable performance in language and visuospatial domains. Post-operative improvements occurred on a cognitive screening measure, verbal memory, and a test of problem-solving skills. This is the first report on an individual with XDP who was cognitively impaired, but had good outcome following GPi bilateral stimulation to treat debilitating motor symptoms. The possible mechanisms for his stable cognitive performance include the target of his DBS, reduced medication dosage, and improvement in dystonia that may in turn have reduced patient's pain.

Infection in the context of implant surgery is a dreaded complication, usually necessitating the removal of all affected hardware. Severe dystonia is a debilitating condition that can present as an emergency and can occasionally be life threatening. The authors present 2 cases of severe dystonia in which deep brain stimulation was maintained despite the presence of infection, using ongoing stimulation by externalization of electrode wires and an extracorporeal pulse generator. This allowed the infection to clear and wounds to heal while maintaining stimulation. This strategy is similar to that used in the management of infected cardiac pacemakers. The authors suggest that this prolonged extracorporeal stimulation should be considered by neurosurgeons in the face of this difficult clinical situation.

Objective: To report the clinical benefits of bilateral deep brain stimulation (DBS) of the globus pallidus internus (GPi) in a patient with X-linked dystonia parkinsonism (XDP)., Design: Case report., Setting: Tertiary referral center. Patient A 40-year-old Filipino man with genetically confirmed XDP and severely disabling generalized dystonia. Intervention Bilateral GPi DBS., Main Outcome Measures: The primary outcome measures were the Burke-Fahn-Marsden Dystonia Scale (BFMDS) severity and disability scores, and the secondary outcome measure was the Unified Parkinson Disease Rating Scores., Results: At the 1-year postoperative follow-up, there was 80.4% improvement in the BFMDS severity score and 66.7% improvement in the BFMDS disability score., Conclusion: Bilateral GPi DBS seems to be very effective in improving dystonia in XDP.

Background: Cerebral palsy (CP) with dystonia-choreoathetosis is a common cause of disability in children and in adults, and responds poorly to medical treatment. Bilateral pallidal deep brain stimulation (BP-DBS) of the globus pallidus internus (GPi) is an effective treatment for primary dystonia, but the effect of this reversible surgical procedure on dystonia-choreoathetosis CP, which is a subtype of secondary dystonia, is unknown. Our aim was to test the effectiveness of BP-DBS in adults with dystonia-choreoathetosis CP., Methods: We did a multicentre prospective pilot study of BP-DBS in 13 adults with dystonia-choreoathetosis CP who had no cognitive impairment, little spasticity, and only slight abnormalities of the basal ganglia on MRI. The primary endpoint was change in the severity of dystonia-choreoathetosis after 1 year of neurostimulation, as assessed with the Burke-Fahn-Marsden dystonia rating scale. The accuracy of surgical targeting to the GPi was assessed masked to the results of neurostimulation. Analysis was by intention to treat., Findings: The mean Burke-Fahn-Marsden dystonia rating scale movement score improved from 44.2 (SD 21.1) before surgery to 34.7 (21.9) at 1 year post-operatively (p=0.009; mean improvement 24.4 [21.1]%, 95% CI 11.6-37.1). Functional disability, pain, and mental health-related quality of life were significantly improved. There was no worsening of cognition or mood. Adverse events were related to stimulation (arrest of the stimulator in one patient, and an adjustment to the current intensity in four patients). The optimum therapeutic target was the posterolateroventral region of the GPi. Little improvement was seen when the neurostimulation diffused to adjacent structures (mainly to the globus pallidus externus [GPe])., Interpretation: Bilateral pallidal neurostimulation could be an effective treatment option for patients with dystonia-choreoathetosis CP. However, given the heterogeneity of motor outcomes and the small sample size, results should be interpreted with caution. The optimum placement of the leads seemed to be a crucial, but not exclusive, factor that could affect a good outcome., Funding: National PHRC; Cerebral Palsy Foundation: Fondation Motrice/APETREIMC; French INSERM Dystonia National Network; Medtronic.

To report a case of exacerbation of blepharospasm after bilateral globus pallidus internus (GPi) deep brain stimulator (DBS) placement. A 69-year-old male presented after bilateral GPi DBS placement for blepharospasm and craniocervical dystonia with worsening eyelid spasms and associated apraxia of lid opening (ALO). Numerous attempts to adjust DBS parameters were ineffective. Consequently, bilateral upper eyelid myectomy was performed. Myectomy surgery was free of complications. The patient had significant improvement of blepharospasm and ALO. Although early success has been reported with DBS placement in a small number of patients with focal dystonias, further studies and longer follow-up are needed to demonstrate whether this will prove to be a useful approach in the treatment of blepharospasm. Upper eyelid myectomy can provide an effective means for treating blepharospasm and associated ALO., (2008 Movement Disorder Society)

Bilateral striatal necrosis (BSN) is relatively rare and has been related to a wide array of causes, including nuclear and mitochondrial DNA mutations. We report the clinical vignette of a patient with a 37 year-history of generalized dystonia secondary to BSN associated with multiple mitochondrial DNA deletions of undefined origin. Globus pallidus interna deep brain stimulation produced sustained benefit, with predominant improvements in disability., (2007 Movement Disorder Society)

Object: Medically refractory dystonia has recently been treated using deep brain stimulation (DBS) targeting the globus pallidus internus (GPI). Outcomes have varied depending on the features of the dystonia. There has been limited literature regarding outcomes for refractory dystonia following DBS of the subthalamic nucleus (STN)., Methods: Four patients with medically refractory, predominantly cervical dystonia underwent STN DBS. Intraoperative assessments with the patients in a state of general anesthesia were performed to determine the extent of fixed deformities that might predict outcome. Patients were rated using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) preoperatively and 3 and 12 months following surgery by a rater blinded to the study. Mean changes and standard errors of the mean in scores were calculated for each subscore of the two scales. Scores were also analyzed using analysis of variance and probability values were generated. Neuropsychological assessments and quality of life ratings using the 36-Item Short Form Health Survey (SF-36) were evaluated longitudinally., Results: Significant improvements were seen in motor (p = 0.04), disability (p = 0.02), and total TWSTRS scores (p = 0.03). Better outcomes were seen in those patients who did not have fixed deformities. There was marked improvement in the mental component score of the SF-36. Neuropsychological function was not definitively impacted as a result of the surgery., Conclusions: Deep brain stimulation of the STN is a novel target for dystonia and may be an alternative to GPI DBS. Further studies need to be performed to confirm these conclusions and to determine optimal candidates and stimulation parameters.

We report on the case of a woman with generalized dystonia and restless legs syndrome whose restless legs resolved after bilateral internal globus pallidus deep brain stimulation, and recurred unilaterally after an infection required removal of one of the devices., (Copyright 2004 Movement Disorder Society.)

Deep brain stimulation (DBS) therapy is a continually expanding field in the functional neurosurgical treatment of movement disorders. However, the occurrence of adverse events related to implanted hardware cannot be overlooked. We report on a specific feature noted in our experience of DBS-related complications. From 1998 until present we have found an overall rate of 5.3% of DBS electrode lead dysfunction (out of 133 patients) in our series (slipped leads 2.3%, lead fracture 3.8%). Interestingly, all of these failures occurred in dystonia patients (18.4% of all dystonia patients and 9.2% of all electrodes). We postulate on mechanisms that may explain why these complications predominate in this group of patients.