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Introduction: Deep brain stimulation (DBS) is a routine neurosurgical procedure utilized to treat various movement disorders including Parkinson's disease (PD), essential tremor (ET), and dystonia. Treatment efficacy is dependent on stereotactic accuracy of lead placement into the deep brain target of interest. However, brain shift attributed to pneumocephalus can introduce unpredictable inaccuracies during DBS lead placement. This study aimed to determine whether intracranial air is associated with brain shift in patients undergoing staged DBS surgery., Methods: We retrospectively evaluated 46 patients who underwent staged DBS surgery for PD, ET, and dystonia. Due to the staged nature of DBS surgery at our institution, the first electrode placement is used as a concrete fiducial marker for movement in the target location. Postoperative computed tomography (CT) images after the first electrode implantation, as well as preoperative, and postoperative CT images after the second electrode implantation were collected. Images were analyzed in stereotactic targeting software (BrainLab); intracranial air was manually segmented, and electrode shift was measured in the x, y, and z plane, as well as a Euclidian distance on each set of merged CT scans. A Pearson correlation analysis was used to determine the relationship between intracranial air and brain shift, and student's t test was used to compare means between patients with and without radiographic evidence of intracranial air., Results: Thirty-six patients had pneumocephalus after the first electrode implantation, while 35 had pneumocephalus after the second electrode implantation. Accumulation of intracranial air following the first electrode implantation (4.49 ± 6.05 cm3) was significantly correlated with brain shift along the y axis (0.04 ± 0.35 mm; r (34) = 0.36; p = 0.03), as well as the Euclidean distance of deviation (0.57 ± 0.33 mm; r (34) = 0.33; p = 0.05) indicating statistically significant shift on the ipsilateral side. However, there was no significant correlation between intracranial air and brain shift following the second electrode implantation, suggesting contralateral shift is minimal. Furthermore, there was no significant difference in brain shift between patients with and without radiographic evidence of intracranial air following both electrode implantation surgeries., Conclusion: Despite observing volumes as high as 22.0 cm3 in patients with radiographic evidence of pneumocephalus, there was no significant difference in brain shift when compared to patients without pneumocephalus. Furthermore, the mean magnitude of brain shift was <1.0 mm regardless of whether pneumocephalus was presenting, suggesting that intracranial air accumulation may not produce clinical significant brain shift in our patients., (© 2024 S. Karger AG, Basel.)

Introduction: L-2-hydroxyglutaric aciduria (L2HGA) is a rare neurometabolic disorder marked by progressive and debilitating psychomotor deficits. Here, we report the first patient with L2HGA-related refractory dystonia that was managed with deep brain stimulation to the bilateral globus pallidus internus (GPi-DBS)., Case Presentation: We present a 17-year-old female with progressive decline in cognitive function, motor skills, and language ability which significantly impaired activities of daily living. Neurological exam revealed generalized dystonia, significant choreic movements in the upper extremities, slurred speech, bilateral dysmetria, and a wide-based gait. Brisk deep tendon reflexes, clonus, and bilateral Babinski signs were present. Urine 2-OH-glutaric acid level was significantly elevated. Brain MRI showed extensive supratentorial subcortical white matter signal abnormalities predominantly involving the U fibers and bilateral basal ganglia. Genetic testing identified a homozygous pathogenic mutation in the L-2-hydroxyglutarate dehydrogenase gene c. 164G>A (p. Gly55Asp). Following minimal response to pharmacotherapy, GPi-DBS was performed. Significant increases in mobility and decrease in dystonia were observed at 3 weeks, 6 months, and 12 months postoperatively., Conclusion: This is the first utilization of DBS as treatment for L2HGA-related dystonia. The resulting significant improvements indicate that pallidal neuromodulation may be a viable option for pharmaco-resistant cases, and possibly in other secondary metabolic dystonias., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Introduction: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an efficient treatment of primary dystonia. Few studies have reported the effect of STN-DBS on secondary or acquired dystonia., Methods: We reported 2 patients with acquired dystonia treated by subthalamic DBS and followed up for 24 months, besides providing a systematic review and meta-analysis of published series., Results/conclusions: Both patients had thalamic vascular or autoimmune lesions within the ventral and the pulvinar nuclei. A reduction of 67.2% on the Burke-Fahn-Marsden Dystonia Rating Scale and 90% improvement in disability scores were shown in the first patient, while the second patient showed a lower reduction in both dystonia symptoms (28.6%) and disability scores (44%). Both patients had a significant mean improvement in the quality of life (62.5% in the first and 57.9% in the second) and were free of drugs postoperatively. A systematic review showed a mean follow-up of 13 months in 19 patients, including our 2 patients. The review showed a significant Burke-Fahn-Marsden Dystonia Scale (BFMDRS) score median reduction of 19 points (52.4%; confidence interval [CI]: 11.0-25.0) and a significant median reduction of 6 points in disability scores (44.5%; 95% CI: 4.0-14.0), thereby improving quality of life. Age at surgery was inversely correlated with postoperative improvement (r = 0.63; p = 0.039). Hemidystonia had a nonsignificant better improvement than generalized dystonia (55.3 vs. 43.5%; p = 0.4433). No association between etiology and postoperative improvement and no serious complications were found. Although few data reported so far, subthalamic DBS is likely efficient for acquired dystonia., (© 2021 S. Karger AG, Basel.)

Background: The introduction of intracranial air (ICA) during deep brain stimulation (DBS) surgery is thought to have a negative influence on targeting and clinical outcomes., Objective: To investigate ICA volumes following surgery and other patient-specific factors as potential variables influencing translocation of the DBS electrode and proximal lead bowing., Methods: High-resolution postoperative computed tomography scans (≤1.0 mm resolution in all directions) within 24 h following DBS surgery and 4-6 weeks of follow-up were acquired. A total of 50 DBS leads in 33 patients were available for analysis. DBS leads included Abbott/St. Jude Medical InfinityTM, Boston Scientific VerciseTM, and Medtronic 3389TM., Results: Both ICA volume and anatomical target were significantly associated with measures of DBS electrode translocation. ICA volume and DBS lead model were found to be significant predictors of proximal lead bowing. Measures of proximal lead bowing and translocation along the electrode trajectory for the Medtronic 3389TM DBS lead were significantly larger than measures for the Abbott/St. Jude Medical InfinityTM and Boston Scientific VerciseTM DBS leads., Conclusion: The association between ICA volume and translocation of the DBS electrode is small in magnitude and not clinically relevant for DBS cases within a normal range of postoperative subdural air volumes. Differences in proximal lead bowing observed between DBS leads may reflect hardware engineering subtleties in the construction of DBS lead models., (© 2020 S. Karger AG, Basel.)

Introduction: A wide range of pulse widths (PWs) has been used in globus pallidus internus (GPi) deep brain stimulation (DBS) for dystonia. However, no specific PW has demonstrated clinical superiority, and the paradigm may differ among DBS centers., Objective: To investigate how different paradigms of PWs in GPi DBS for dystonia affect implantable pulse generator (IPG) longevities and energy consumption., Methods: Thirty-nine patients with dystonia treated with bilateral GPi DBS at 2 Swedish DBS centers from 2005 to 2015 were included. Different PW paradigms were used at the 2 centers, 60-90 µs (short PWs) and 450 µs (long PW), respectively. The frequency of IPG replacements, pulse effective voltage (PEV), IPG model, pre-/postoperative imaging, and clinical outcome based on the clinical global impression (CGI) scale were collected from the medical charts and compared between the 2 groups., Results: The average IPG longevity was extended for the short PWs (1,129 ± 50 days) compared to the long PW (925 ± 32 days; χ2 = 12.31, p = 0.0005, log-rank test). IPG longevity correlated inversely with PEV (Pearson's r = -0.667, p < 0.0001). IPG longevities did not differ between Kinetra® and Activa® PC in the short (p = 0.319) or long PW group (p = 0.858). Electrode distances to the central sensorimotor region of the GPi did not differ between the short or long PW groups (p = 0.595). Pre- and postoperative CGI did not differ between groups., Conclusions: Short PWs were associated with decreased energy consumption and increased IPG longevity. These effects were not dependent on the IPG model or the anatomic location of the electrodes. PWs did not correlate with symptom severities or clinical outcomes. The results suggest that the use of short PWs might be more energy efficient and could therefore be preferred initially when programming patients with GPi DBS for dystonia., (© 2020 S. Karger AG, Basel.)

Background: Medically refractory dystonia affects children and young adults, and deep brain stimulation (DBS) can allow some patients to regain functional independence. Women with dystonia treated with DBS may wish to conceive a child, but there is limited published information on pregnancy and DBS., Objective: To describe a series of dystonia patients treated with DBS who later became pregnant and provide guidelines for women treated with DBS considering conception., Methods: We reviewed all dystonia DBS cases implanted at the University of California, San Francisco, and University of Alabama at Birmingham from 1998 to 2015 and identified patients who became pregnant. Patient records were reviewed and structured interviews were conducted., Results: Six dystonia patients were identified [1 currently pregnant and 7 live births (including 1 twin pair)]. Patients (n = 5) with pre- and postoperative BFMDRS (Burke-Fahn-Marsden Dystonia Rating Scale) scores improved by 65.9% after DBS. All pregnancies and deliveries were uncomplicated (the delivery mode was not influenced by the presence of DBS), except for 1 child, who was born premature at 35 weeks' gestation. Stimulation remained on (n = 3) or off (n = 4) during deliveries. DBS neurostimulators did not hinder breastfeeding., Conclusions: In this small sample, pregnancy, delivery, and breastfeeding were safe in dystonia patients treated with DBS. The presence of DBS should not be a contraindication to pregnancy., (© 2016 S. Karger AG, Basel.)

Background: Deep brain stimulation (DBS) is a surgical treatment involving the implantation of a brain lead connected to a chest-based neurostimulator similar to a cardiac pacemaker. The device can be programmed to deliver electrical impulses to neuromodulate abnormal brain circuitry in disorders such as Parkinson's disease (PD), essential tremor (ET), and dystonia. As the number of patients receiving DBS surgery increases, it will be important for primary care doctors to identify reasonable DBS candidates for referral to an experienced center., Objective: To provide primary care physicians with a rationale and also to provide clinically useful pearls for referral of potential DBS candidates., Methods: A complete PubMed review of the literature., Results: This review will be focused on PD and ET and will address the following issues: what are the common motor and nonmotor symptoms? What is the evidence supporting the use of DBS in PD and ET? What is the importance of a multi- or interdisciplinary DBS team for patient selection? What can be done to improve success in identifying and referring potential DBS candidates?, Conclusion: DBS is a highly effective therapy for select candidates with PD and ET. The most important factor influencing DBS outcome is proper patient selection. It will be critical as DBS continues to be more commonly employed for primary care doctors to select candidates from their practices as appropriate referrals to specialized centers.

Background: Deep brain stimulation (DBS) for the treatment of movement disorders has provided researchers with an opportunity to record electrical oscillatory activity from electrodes implanted in deep brain structures. Extracellular activity recorded from a population of neurons, termed local field potentials (LFPs), has shed light on the pathophysiology of movement disorders and holds the potential to lead to refinement in existing treatments., Objective: This paper reviews the clinical significance of LFPs recorded from macroelectrodes implanted in basal ganglia and thalamic targets for the treatment of Parkinson's disease, essential tremor and dystonia., Methods: Neural population dynamics and subthreshold events, which are undetectable by single-unit recordings, can be examined with frequency band analysis of LFPs (frequency range: 1-250 Hz)., Results: Of clinical relevance, reliable correlations between motor symptoms and components of the LFP power spectrum suggest that LFPs may serve as a biomarker for movement disorders. In particular, Parkinson's rigidity has been shown to correlate with the power of beta oscillations (13-30 Hz), and essential tremor coheres with oscillations of 8-27 Hz. Furthermore, evidence indicates that the optimal contacts for DBS programming can be predicted from the anatomic location of beta and gamma bands (48-200 Hz)., Conclusion: LFP analysis has implications for improved electrode targeting and the development of a real-time, individualized, 'closed-loop' stimulation system., (2014 S. Karger AG, Basel.)

Huntington's disease (HD) is an autosomal dominant and progressive neurodegenerative syndrome characterized by motor, cognitive and psychiatric manifestations. Chorea and dystonia are features that may be troublesome to some patients and may potentially prove unresponsive to pharmacological treatments. There are several reports on the results of globus pallidus internus deep brain stimulation (DBS) surgery for HD. In these published cases, DBS was utilized mainly to treat disabling chorea. We report our experience with 2 HD cases treated with DBS. The cases illustrate a differential response with a better outcome in the choreic presentation compared to the dystonic presentation. Additionally, DBS worsened gait features in both cases., (Copyright © 2013 S. Karger AG, Basel.)

Background: Deep brain stimulation (DBS) is a recognised method of treatment for primary and secondary dystonia. The size of non-rechargeable batteries has limited their use in small children. Our severe dystonia patients have required battery replacement every 20-24 months., Objectives: To evaluate reliability, care burden, patients' satisfaction and complications related to the rechargeable neurostimulator Activa® RC (launched by Medtronic in Europe in autumn 2008)., Methods: Complications were recorded prospectively, and a questionnaire on neurostimulator maintenance, care burden and parental satisfaction was applied to all patients with at least 3 months of follow-up., Results: 30 Activa RCs were implanted between December 2008 and June 2010, 25 with a follow-up of 3-17 months (mean 10); the mean patient's age at surgery was 11.1 years; 22/25 questionnaires were completed. All families achieved good standards of recharging. Caregivers were responsible for recharging in 82% of cases. With higher parameters of stimulation, recharging time was longer than initially recommended by the manufacturer. All but one family would recommend Activa RC to other patients. Transient recharging problems were the most common complication (36% of cases). Infection/skin erosion occurred in 8% of cases, self-resolving early seroma in 20%., Conclusions: Activa was found to offer reliable stimulation with a low rate of significant complications and a suitable treatment option for children with dystonia., (Copyright © 2012 S. Karger AG, Basel.)

Introduction: Globus pallidus internus (GPi) deep brain stimulation (DBS) represents a validated, effective, and safe treatment for patients affected by generalized dystonia resistant to conservative treatment. Segmental and multisegmental dystonia have more recently been proposed as further indications for GPi DBS despite the lack of long-term homogenous follow-up. Here we present an original and detailed long-term follow-up (5 years) of a homogeneous population of 11 patients affected by segmental or multisegmental dystonia., Materials and Methods: Ten patients underwent bilateral GPi DBS electrode implantations under a Leksell stereotactic guide, with intraoperative neurophysiological monitoring. The follow-ups at 1, 3 and 5 years were collected using video-BFMDRS for motor and disability scores. The statistical analysis of the results is provided., Results: We reported a statistically significant improvement in motor and disability overall scores until 5 years after treatment. At the last follow-up, even the single motor subitems were statistically improved., Discussion: We observed a continuous and statistically significant improvement in all of the motor subitems and in the overall disability score until the 3-year follow-up. These results did not improve any further but they appeared steady at the last follow-up. We also report a significant improvement in the cranial-cervical subitems., Conclusions: GPi DBS should definitely be considered a safe and effective treatment also for segmental and multisegmental dystonia even in cases of relevant or prevalent cranial-cervical involvement., (Copyright © 2012 S. Karger AG, Basel.)

Background: Weight gain has been described in Parkinson's disease (PD) patients after subthalamic nucleus (STN) deep brain stimulation (DBS)., Objectives: We examined change in weight following DBS in both PD and dystonia patients to further investigate the role of disease and brain target (STN or globus pallidus internus, GPi) specificity., Methods: Data was retrospectively collected on 61 PD DBS patients (STN n = 31 or GPi n = 30) and on 36 dystonia DBS patients (STN n = 9 and GPi n = 27) before and after surgery. Annual change in body mass index (BMI) was evaluated with nonparametric tests between groups and multiple quantile regression., Results: PD patients treated with STN DBS had a small increase in median BMI while those with GPi had a small decrease in BMI. Dystonia patients treated with STN DBS had a greater increase in BMI per year compared to those treated with GPi DBS. Multivariable regression analyses for each disease showed little difference between targets in weight gain in those with PD, but STN target was strongly associated with weight gain in dystonia patients (STN vs. GPi, +7.99 kg, p = 0.012)., Conclusions: Our results support previous reports of weight gain after DBS in PD. This is the first report to suggest a target-specific increase in weight following STN DBS in dystonia patients., (Copyright © 2012 S. Karger AG, Basel.)

Background/aims: Venous air embolism (VAE) is a potential complication during neurosurgical procedures, particularly in the sitting position. The diagnosis and management of VAE in patients undergoing awake deep brain stimulation (DBS) lead implantation in the sitting position are underreported., Methods: We performed a retrospective chart review of 467 consecutive DBS surgeries at the University of California, San Francisco. Data was collected for patient demographics, diagnosis, intraoperative events, and postoperative course., Results: Six cases of clinically diagnosed VAE were found, amounting to a total incidence of 1.3% per procedure. We did not observe a statistical association with patient age, diagnosis, or DBS target. The most common symptoms of intraoperative VAE were coughing, oxygen desaturation, and hypotension. In all cases, VAE was treated by copious irrigation of the surgical field and lowering the patient's head. In 4 cases, DBS implantation was abandoned because of ongoing symptoms of VAE. The respiratory outcome in all patients was good after several days of close observation., Conclusion: The incidence of VAE during DBS procedures is small, but prompt recognition and management of VAE are critical to avoid further associated complications., (Copyright © 2011 S. Karger AG, Basel.)

Camptocormia (CC) is defined as a trunkal flexion which worsens while standing, sitting and walking and disappears in the supine position. CC is a well-known clinical phenomenon in patients with generalized neuromuscular disorders like polymyositis, myasthenia gravis or motor neuron diseases, and it is also described in the context of movement disorders like Parkinson's disease (PD) or multiple system atrophy. In association with PD, CC seems to be a rare symptom which occurs preferentially in late stages of the disease. Currently, there are 3 main hypotheses on the pathogenesis of CC in PD, i.e. a focal myopathy of the trunk muscles, axial dystonia and a drug-induced etiology. This review gives a synopsis and critical acclaim of these 3 etiologies and refers to the current study data and possible treatment strategies., (Copyright © 2011 S. Karger AG, Basel.)

Objective: Although deep brain stimulation (DBS) is nonablative, it may give rise to many complications. In order to identify and reduce factors contributing to the complications, we performed a retrospective analysis of patients who received DBS in our institution over a 9-year period from March 2000 to December 2008., Methods: Included in this study were 161 patients (85 male and 76 female). Data from these patients were collected and analyzed with respect to the complications and factors potentially related to these complications., Results: A total of 25 surgical and hardware-related complications occurred in 24 patients, including confusion in 11 cases (6.83%), asymptomatic intracranial hemorrhage in 1 case (0.62%), electrode misplacement in 2 cases (1.24%), infection of the subcutaneous pocket receiving the pulse generator in 1 case (0.62%), skin erosion in 2 cases (1.24%), pulse generator seroma formation in 6 cases (3.72%), and device malfunction in 1 case (0.62%). There was no permanent neurological deficit., Conclusion: Confusion is the most common complication in simultaneous bilateral DBS targeting the subthalamic nucleus, especially in patients with severe Parkinson's disease. With increasing experience of surgeons, complete obedience to intraoperative surgical routines and reasonable application of the microelectrode recording technique, other complications could also be reduced., (2010 S. Karger AG, Basel.)

Background: X-linked dystonia-parkinsonism (XDP; DYT3; Lubag) is an adult-onset hereditary progressive dystonia/parkinsonism which is typically minimally responsive to pharmacological treatment., Case Report: We report a 63- year-old man with a diagnosis of XDP who underwent bilateral globus pallidus internus deep brain stimulator (GPi-DBS) placement. His course initially began with right hand tremor and dystonia at age 57 and progressed to also include bradykinesia and rigidity. The patient tolerated the procedure without significant complications. GPi-DBS improved his right hand dystonia, but did not significantly improve his parkinsonism., Conclusion: DBS may be a therapeutic option for select cases of XDP, but its specific indications must be carefully discussed, as the available cases have had mixed responses. Whether other targets may be more effective is not known., (2010 S. Karger AG, Basel.)

Background: To maintain the efficacy of deep brain stimulation (DBS) on dystonic symptoms, slight incremental increase in voltage may be necessary over years after a steady state has been reached following the initial programming of optimal settings. So far however, no data are available regarding the adjustment of voltage after implantable pulse generator (IPG) replacement to achieve sustained optimal control of dystonia with the least side effects., Methods: We analyzed stimulation settings before and after IPG replacement for battery depletion (n = 61) in 18 patients with chronic DBS of the globus pallidus internus or the ventral intermediate nucleus of the thalamus for dystonia., Results: The stimulation intensity could be significantly reduced by 24.8% after IPG replacement. The amount of voltage reduction was equal between bipolar and monopolar stimulation modes (24.9 vs. 24.3%, p = 0.89) and significantly correlated with the magnitude of stimulation intensity before IPG replacement (ρ = 0.429, p = 0.001)., Conclusions: After IPG replacement, in patients with DBS for segmental dystonia the voltage can be reduced by approximately 25%. This phenomenon might be explained by a gradual decrease in the electrical energy effectively delivered by the IPG in the course of the lifetime of the battery or neuroplastic processes in particular in the period around battery replacement., (2010 S. Karger AG, Basel.)

Background/aims: During the placement of electrodes for deep brain stimulation (DBS), patients are commonly in a seated position, awake, and spontaneously breathing. Air may be entrained through bone or dural veins causing venous air emboli (VAE) and this phenomenon can result in significant hemodynamic changes. Although VAEs have been described in many types of neurosurgical procedures, their incidence during DBS surgery is unknown., Methods: Following approval from the Institutional Review Board, the University of Florida Movement Disorders Center database comprising 286 DBS leads placed since 2002 was reviewed. Intraoperative cough, which has been associated with VAE, as well as hemodynamic instability were the focus of the review. Additionally, a prospective evaluation of the incidence of VAE using precordial Doppler ultrasound was undertaken over a 3-month period (June 2007-August 2007)., Results: The retrospective review revealed a 3.2% incidence of cough per lead. Prospective monitoring in 21 consecutive patients with 22 leads yielded the detection of 1 VAE, and an incidence of 4.5% per lead., Conclusion: VAEs are rare but potentially serious complications of DBS surgery unless recognized. Patient positioning and the occurrence of cough are two important predictors to consider in VAE. Precordial Doppler is a safe, non-invasive monitor that can be used in the early detection of VAE in these procedures.

Background: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is an effective and well-tolerated treatment for idiopathic generalized dystonia. More recently, it has been applied as a treatment for focal and segmental dystonias. This patient population offers an opportunity to study the effects of alteration of pallidal outflow on previously normal limb function., Methods: We sought to retrospectively characterize the extent of novel GPi DBS-induced adverse motor effects in patients with adult-onset cervical and cranial-cervical dystonia using a questionnaire, and compared the findings to dystonia improvement as measured by standard scales., Results: Despite significant improvement in dystonia (65% in mean Burke-Fahn-MarsdenDystonia Rating Scale motor score, p < 0.005, and 59% in mean Toronto Western Spasmodic Torticollis Rating Scale score, p < 0.008), slowing and difficulty with normal motor function was reported in previously nondystonic extremities in 10 of 11 patients. Symptoms were common in both upper and lower extremities and included new difficulties with handwriting (82%), getting up from a chair or in/out of a car (73%), and walking (45%), and were not associated with aberrant lead placement near the internal capsule., Conclusion: Although GPi DBS was shown to be effective in these patients, the influence of GPi DBS on nondystonic body regions deserves further investigation.

Background: Widely reported long-term complications following implantation of deep brain stimulation (DBS) hardware include breakage of electrode leads, internal pulse generator (IPG) failure, skin erosions and infection. Here we report on a rarely described problem that arises from formation of scar tissue adhesions around the DBS extension wire(s). Over time, this scar tissue can become tight and pronounced, protruding noticeably beneath the skin ('bowstringing' in reference to its tight bow-like appearance) and leading to significant limitation of movement and discomfort. We term this 'wire tethering'., Results: We describe 6 patients with moderate to severe wire tethering. Review of our experience suggests an association of wire tethering with the passage of two extension wires on the same side as is done when using a dual-channel IPG. Five of the patients required surgical revision of the extension wires due to the magnitude of the discomfort, limitation of movement and appearance. Removing the wires was insufficient in the most severe case, necessitating transection of the scar in several places, which was done with the extension wires in situ in 2 patients. Two patients were treated with removal of the wires alone, and 1 patient did not opt for surgery and the tethering has persisted., Conclusion: Wire tethering, or 'bowstringing', is an underrecognized complication of DBS hardware implantation often necessitating surgical revision. The possible etiology of wire tethering is discussed as well as suggestions for its avoidance., ((c) 2009 S. Karger AG, Basel.)

Background: Several subcortical structures have been targeted for surgical treatment of dystonia, including motor thalamus, internal segment of globus pallidus (GPi), and more recently, the subthalamic nucleus (STN). Deep brain stimulation of GPi is currently the preferred surgical treatment, but it is unclear if targeting other structures would yield better results. Patients who have already had a pallidotomy yet continue to experience dystonic symptoms may be limited in further treatment options., Methods: A patient with medically intractable, segmental, early-onset, primary torsion dystonia presented for surgical consultation after exhausting nearly all treatment options. Medications, botulinum toxin injections, cervical denervation surgery, and left-sided pallidotomy failed to give adequate relief. The patient was implanted with STN stimulating leads bilaterally according to standard procedures., Results: The patient received a 36% improvement in dystonic symptoms as measured by several dystonia rating scales. These benefits persisted for 2 years after surgery despite several hardware-related complications, and the patient reported being very satisfied with the outcome., Conclusion: This result supports the efficacy of STN deep brain stimulation in dystonia patients, even those with prior pallidotomy., ((c) 2007 S. Karger AG, Basel)

The aim of the study was to investigate if laser Doppler perfusion monitoring (LDPM) can be used in order to differentiate between gray and white matter and to what extent microvascular perfusion can be recorded in the deep brain structures during stereotactic neurosurgery. An optical probe constructed to fit in the Leksell Stereotactic System was used for measurements along the trajectory and in the targets (globus pallidus internus, subthalamic nucleus, zona incerta, thalamus) during the implantation of deep brain stimulation leads (n = 22). The total backscattered light intensity (TLI) reflecting the grayness of the tissue, and the microvascular perfusion were captured at 128 sites. Heartbeat-synchronized pulsations were found at all perfusion recordings. In 6 sites the perfusion was more than 6 times higher than the closest neighbor indicating a possible small vessel structure. TLI was significantly higher (p < 0.005) and the perfusion significantly lower (p < 0.005) in positions identified as white matter in the respective MRI batch. The measurements imply that LDPM has the potential to be used as an intracerebral guidance tool., ((c) 2007 S. Karger AG, Basel.)

The renaissance of functional neurosurgery in the treatment of Parkinson's disease has sparked also the interest in other movement disorders which are refractory to medical treatment. Deep brain stimulation (DBS) has been used only since a few years in dystonia patients. This review summarizes the available data on pallidal and thalamic DBS for various dystonic syndromes. The major advantage of DBS as compared to radiofrequency lesioning is that it allows performing contemporaneous bilateral surgery with relatively low morbidity in these patients. The posteroventral lateral globus pallidus internus (GPi) has been the preferred target in most instances, thus far. While phasic dystonic movements may improve early after surgery, the response of tonic dystonic movements to chronic stimulation may be delayed. The most beneficial results have been achieved in patients with primary genetic generalized and segmental dystonia, myoclonic dystonia, and complex cervical dystonia. Outcome has been varied in patients with other dystonic disorders, in particular those with secondary dystonia. Most studies have reported on relatively short follow-up periods, on single cases, or were retrospective. Pallidal DBS has been shown to be effective in complex cervical dystonia yielding both symptomatic and functional benefit for up to 2.5 years of follow-up. Dramatic improvement has been obtained in children and in adults with DYT1 positive dystonia. Also, patients with non DYT1 genetic dystonia achieved sustained benefit for up to 2 years of follow-up. Preliminary experience indicates that choreoathetosis in patients with cerebral palsy responds less well to pallidal DBS, and that it may not be effective at all in some patients. In single instances unilateral pallidal DBS has been shown to yield valuable benefit in patients with hemidystonia. The experience with DBS for treatment of Meige syndrome and other focal dystonias has been explored only recently. There is much less experience with thalamic DBS for dystonia. Thalamic DBS has been shown to be effective in single cases with posttraumatic dystonia, postanoxic dystonia and paroxysmal nonkinesigenic dystonia. Future perspectives of DBS for treatment of dystonia include the development of new technology, the evaluation of the possible role of other targets, and carefully planned studies to further establish the role of surgery., (Copyright 2002 S. Karger AG, Basel)

Stimulation electrodes are implanted under general anesthesia, without intra-operative electrophysiology or clinical testing, based only on stereotactic MRI and direct anatomical localization of the postero-ventro-basal GPi. We retrospectively analyzed the surgical procedure that has been designed and implemented in our center, using the Leksell G frame, for initiating deep brain stimulation in 65 dystonic patients. We report the surgical technique and the hardware and software complications. We recommend immediate postoperative stereotactic MRI under general anesthesia as a prerequisite to check the reliability of MR acquisition (magnet stability) and the exact localization of each electrode. This technique allowed us to reduce the duration of the operation to 4 h, including general anesthesia, frame fixation, MRI acquisition, implantation of two electrodes under radioscopic control, immediate postoperative stereotactic MRI and frame removal. Surgery-related morbidity was very low with a 0% hemorrhage rate and three delayed unilateral infections re-operated 6 months later. Hardware and software complications were rare. The advances in 3D-MR imaging permit the electrode implantation for deep brain stimulation without resorting to intraoperative localization techniques, which is especially helpful in children and for treating dystonia. The maximum follow-up period is 58 months (first case: November 1996). GPi stimulation has proven to be an effective treatment for most dystonic syndromes with particular efficacy in the disease due to the DYT1 mutation., (Copyright 2002 S. Karger AG, Basel)

Deep brain stimulation (DBS) represents a major advance in the treatment of Parkinson's disease (PD). As more neurosurgeons enter this field, technical descriptions of implantation techniques are needed. Here we present our technical approach to subthalamic nucleus (STN) and globus pallidus internus (GPi) DBS implantation, based on 180 STN implants and 75 GPi implants. The essential steps in DBS implantation are magnetic resonance imaging (MRI)-guided stereotactic localization, confirmation of the motor territory of the target nucleus with microelectrode mapping, and intra-operative test stimulation to determine voltage thresholds for stimulation-induced adverse effects. Lead locations are documented by postoperative MRI in all cases., (Copyright 2002 S. Karger AG, Basel)

Although technological advances have reduced device-related complications, DBS surgery still carries a significant risk of transient and permanent complications. We report our experience in 86 patients and 149 DBS implants. Patients with Parkinson's disease, essential tremor and dystonia were treated. There were 8 perioperative, 8 postoperative, 9 hardware-related complications and 4 stimulation-induced side effects. Only 5 patients (6%) sustained some persistent neurological sequelae, however, 26 of the 86 patients undergoing 149 DBS implants in this series experienced some untoward event with the procedure. Although there were no fatalities or permanent severe disabilities encountered, it is important to extend the informed consent to include all potential complications., (Copyright 2002 S. Karger AG, Basel)

Central cannabinoid receptors are densely located in the output nuclei of the basal ganglia (globus pallidus, substantia nigra pars reticulata), suggesting their involvement in the regulation of motor activity. Furthermore, there is evidence that endogenous cannabinoid transmission plays a role in the manipulation of other transmitter systems within the basal ganglia by increasing GABAergic transmission, inhibiting glutamate release and affecting dopaminergic uptake. Most hyperkinetic and hypokinetic movement disorders are caused by a dysfunction of basal ganglia-thalamo-cortical loops. It has been suggested that an endogenous cannabinoid tone participates in the control of movements and, therefore, the central cannabinoid system might play a role in the pathophysiology of these diseases. During the last years in humans a limited number of clinical trials demonstrated that cannabinoids might be useful in the treatment of movement disorders. Despite the lack of controlled studies there is evidence that cannabinoids are of therapeutic value in the treatment of tics in Tourette syndrome, the reduction of levodopa-induced dyskinesia in Parkinson s disease and some forms of tremor and dystonia. It can be speculated that cannabinoid antagonists might be useful in the treatment of chorea in Huntington s disease and hypokinetic parkinsonian syndromes.

Torsion dystonia in 13-year-old girl progressed to severe opisthotonus and dystonic posturing of the limbs, accompanied by severe psychic changes, cachexia and calcification around joints. Drug therapy was ineffective. Ventrolateral thalamotomy and chlorpromazine brought about a delayed but remarkable amelioration of all symptoms and signs, still present 4 years later.

This report is a continuation of our previous report on chronic spinal cord stimulation in disorders of the motor system. Improved statistics were observed following changing from the early conventional two-electrode system to a newly developed four-electrode system. The success of the four-electrode system lies in the analysis of both the electrode combinations and the frequency of stimulation. These are carried out on each patient and remain the most critical aspect of the technique. The details of the multiple lead system--the technique of implantation and protocols for carrying out electrode and frequency analysis--are presented.

The position of the medial internal capsular border (lateral thalamic border) in relation to the width of the third ventricle is of considerable importance to stereotactic surgeons. Close estimation of its position from anteroposterior roentgenograms diminishes the possibility of multiple brain penetrations in an attempt to find it by electrophysiological methods. By correlating the position of the medial capsular border found by a stimulation technique, with the width of the third ventricle, in a series of 130 patients, reliable ranges of its position were obtained.

4 patients suffering severe neuromuscular diseases were subjected to a subtentorial implantation of electrodes over the anterior cerebellar lobe surface. Chronic stimulation was applied for 90 min to 7 h daily, with a rate of 20--180 Hz, 6--10 V and a schedule of 15 min "on", 15 min "off". Some improvement was observed in 3 patients treated with high frequency stimulation. 1 patient suffered seizures after three months of chronic stimulation. In 2 cases, posterior fossa explorations were necessary for revision of the stimulation apparatus and marked meningeal proliferation surrounding the electrodes was observed. Light and electron microscopic examination of the biopsies showed loss of Purkinje cells and gliofibrillar reaction. Effectiveness and side effects of chronic stimulation of the cerebellum are discussed.