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Background: Hardware-related infection after deep brain stimulation (DBS) is one of the most serious complications and may need additional interventions. Objectives: To reuse the internal pulse generator (IPG) after DBS infection and to reduce the economic costs. Methods: A database of 102 patients who underwent DBS surgery was used in the study. The incidence, clinical characteristics and management of infections while reusing the IPG after DBS-related infection were analyzed and reported. Results: The overall infection rate was 5.9% (6 of 102 patients). Management consisted of total hardware removal followed by intravenous antibiotics. The IPG was at first kept in a solution, then rinsed with water and dried following sterilization with ethylene oxide gas at 38°C for 18 h. When the treatment of the infection was finished, we reused the IPG and reimplanted the DBS. No hardware-related infection or other complications were observed after reimplantation. Conclusions: Management of hardware-related infections can be challenging. The medical and economic costs associated with these infections are enormous. The IPG can often be saved in infected patients. Thus, a significant cost burden is eliminated. Properly executed, reuse of IPG should markedly reduce the costs of these devices.

We report a case of 67 year-old man with Parkinson's disease who has gait disturbance for eight years. The Pedunculopontine Nucleus Deep Brain Stimulation (PPN-DBS) surgery was performed and gait parameters were evaluated by using foot print method. After opening the battery step length and stride length increased, the patienthas been walking the same distance with less number of steps. When the battery closed, the step length was 34.5 cm, following the battery opening it increased to 45.5 cm suggesting that PPN-DBS surgery was an effective treatment to improve gait ability. © 2014, Pakistan Medical Association. All rights reserved.

Background: It has been generally accepted that deep brain stimulation (DBS) not only acts in the nucleus where it is being applied, as initially thought, but that chronic stimulation activates axons located in its scope, and that this activation can exert its effects in distant areas. Considering this, DBS target identification should be made based on techniques that identify white matter tracts, such as tractography, rather than only by identifying specific nuclei on conventional magnetic resonance imaging. Methods: In this study, we performed a review of the literature on the use of tractography in DBS surgery and provide an overview of the main results. Results: Tractography has been used in the field of DBS to help clarify relevant aspects in the selection of targets and in evaluating its therapeutic effects in movement disorders, psychiatric diseases and pain. Conclusions: Studies are scarce so far, but they have provided data that, if confirmed, may optimize DBS surgery. Tractography might become a routine tool for DBS surgery in the near future.

International audience; Deep Brain Stimulation (DBS) surgery is used increasingly as a symptomatic treatment for patients with movement related neuro-degenerative disorders. However, the method of intraoperative symptom evaluation is subjective. This paper proposes a method to quantitatively evaluate tremor by measuring the acceleration of the patient's wrist during the surgery. The results of applying the method to 2 patients suggest that the acceleration measurements are very sensitive to the change in the tremor and that they can be used to identify clinically effective stimulation amplitudes. By collecting acceleration data from DBS surgeries for many patients, we hope to add more knowledge to the mechanisms of deep brain stimulation.

The use of Deep Brain Stimulation (DBS) surgery is increasing as a treatment for movement related disorders. One of the important areas of improvement is the target selection procedure. To do so we measured the acceleration of tremor by sensors in 6 patients during their DBS surgeries to evaluate the changes quantitatively. The post operative data analysis revealed that acceleration measurements are very sensitive to the changes in tremor and that they can be used to identify clinically effective stimulation amplitudes. With the aim to increase objectivity in symptom evaluation we intend to introduce real time analysis so as to provide more information to the neurosurgeon to aid him in his target selection during the surgery. © 2013 by Walter de Gruyter.

Deep-brain stimulation is the most effective surgical treatment for severe Parkinson's disease (PD). Bradykinesia is one of the primary symptoms of PD. 10 s hand grasping movement is used to assess bradykinesia severity in this study. An inertial measurement unit (IMU), which is attached to the middle finger, is used to measure the angular displacement of the middle finger movement during bradykinesia assessment task. The dominant grasping frequency, mean value and standard deviation (SD) of hand grasping ranges are used as the severity features of bradykinesia. Three healthy subjects and four PD patients were tested by the wearable system. The modified mean range correlated well with the 5-point clinical ratings. Further clinical experiments will be performed in the near future.

Beta-band synchronous oscillations in the dorsolateral region of the subthalamic nucleus (STN) of human patients with Parkinson's disease (PD) have been frequently reported. However, the correlation between STN oscillations and synchronization has not been thoroughly explored. The simultaneous recordings of 2390 multi-unit pairs recorded by two parallel microelectrodes (separated by fixed distance of 2 mm, n = 72 trajectories with two electrode tracks >4 mm STN span) in 57 PD patients undergoing STN deep brain stimulation surgery were analyzed. Automatic procedures were utilized to divide the STN into dorsolateral oscillatory and ventromedial non-oscillatory regions, and to quantify the intensity of STN oscillations and synchronicity. Finally, the synchronicity of simultaneously vs. non-simultaneously recorded pairs were compared using a shuffling procedure. Synchronization was observed predominately in the beta range and only between multi-unit pairs in the dorsolateral oscillatory region (n = 615). In paired recordings between sites in the dorsolateral and ventromedial (n = 548) and ventromedial-ventromedial region pairs (n = 1227), no synchronization was observed. Oscillation and synchronicity intensity decline along the STN dorsolateral-ventromedial axis suggesting a fuzzy border between the STN regions. Synchronization strength was significantly correlated to the oscillation power, but synchronization was no longer observed following shuffling. We conclude that STN long-range beta oscillatory synchronization is due to increased neuronal coupling in the Parkinsonian brain and does not merely reflect the outcome of oscillations at similar frequency. The neural synchronization in the dorsolateral (probably the motor domain) STN probably augments the pathological changes in firing rate and patterns of subthalamic neurons in PD patients.

Stereotactic frames are a standard tool for neurosurgical targeting, but are uncomfortable for patients and obstruct the surgical field. Microstereotactic frames are more comfortable for patients, provide better access to the surgical site, and have grown in popularity as an alternative to traditional stereotactic devices. However, clinically available microstereotactic frames require either lengthy manufacturing delays or expensive image guidance systems. We introduce a robotically-adjusted, disposable microstereotactic frame for deep brain stimulation surgery that eliminates the drawbacks of existing microstereotactic frames. Our frame can be automatically adjusted in the operating room using a preoperative plan in less than five minutes. A validation study on phantoms shows that our approach provides a target positioning error of 0.14 mm, which exceeds the required accuracy for deep brain stimulation surgery.

The presence of foreign material in deep brain stimulation is a risk factor for infection, and hardware-related pressure under the scalp may cause skin erosion. The aim of this article is to present our experience in the coverage of scalp in relation to underlying hardware. We analyzed 21 patients with Parkinson disease who had undergone deep brain stimulation surgery and developed scalp erosion with hardware exposition during follow-up. Nine patients were programmed for a scalp rotation flap, whereas free tisue transfer was performed in the rest of the patients. Minimum follow-up was 2 years. A hardware-related ulcer appeared in 5 of 9 rotation flap patients. No ulceration or major complications were observed in free flap patients. Free flaps are probably the best option for stable coverage in hardware-related scalp erosion with a high rate of success.

Introduction Deep brain stimulation (DBS) is a common neurosurgical procedure for relieving movement related disorders such as Parkinson’s disease. DBS extends uncertainties associated with suboptimal target selection. Our aim was to evaluate the feasibility to objectively assess clinical effects obtained during intraoperative test stimulation based on acceleration measurements of the neurologist’s wrist. Methods One patient referred for bilateral DBS-implantation for the treatment of Parkinson’s disease was included in the study. A 3-axis accelerometer was fixed on the neurologist's wrist during intraoperative test stimulation. While the intensity of electric current used for stimulation was increased , the neurologist continuously moved the patient's wrist to determine the moment of and the amplitude at rigidity release ("stimulation threshold"). For each test stimulation position, differrent mathematical features were determined and statistically compared a) for the time period before re aching the stimulation threshold that had been identified by the neurologist and b) after reaching the threshold. We then visually identified the stimulation thresholds that would have been chosen based on the acceleration signal alone and compared them to the ones subjectively identified by the neurologist. Results A statistical significant change in rigidity (p

Background and Objective: Deep brain stimulation (DBS) candidates with neurologic diseases such as unruptured aneurysm present additional challenges to neurosurgeons when craniotomy must precede DBS surgery. Such craniotomy may potentially overlap with intended burr hole sites for the later insertion of DBS electrodes, and the skin incision for craniotomy may lie very close to or intersect with that for the burr holes. We report here a case of forehead craniotomy prior to DBS surgery in which we employed a neuronavigation system to simulate locations for the craniotomy and burr holes. Method: A 62-year-old male patient with Parkinson's disease was a candidate for DBS. He also had an aneurysm and was planned first to undergo frontal craniotomy for clipping before the DBS surgery. The locations of the craniotomy, burr holes, and skin incisions were therefore simulated using a neuronavigation system during craniotomy. Results: Two weeks after the craniotomy, the patient underwent DBS surgery. Planning software confirmed the absence of cortical veins beneath the entry points of tentative burr holes and aided trajectory planning. The DBS surgery was performed without the interference of the burr holes and head pins and the craniotomy. Conclusion: Simulation of the locations of craniotomy and burr holes using a neuronavigation system proved valuable in the present case of frontal craniotomy before DBS surgery.

IntroductionIn Deep Brain Stimulation (DBS) the save, accurate and precise electrode implantation is essential. We have previously presented an optical technique for intra-operative measurements du ...

Fatigue is a common and disabling nonmotor symptom seen in Parkinson’s disease (PD). While deep brain stimulation surgery (DBS) improves motor symptoms, it has also been associated with non-motor side effects. To date no study has utilized standardized instruments to evaluate fatigue following DBS surgery. Our objective was to determine the prevalence of fatigue following DBS surgery in PD its impact on quality of life and explore predictive factors. We recruited 44 PD subjects. At least one year following DBS placement, we administered the Fatigue Severity Scale (FSS), the Parkinson’s Disease Questionnaire (PDQ-39), the Beck Depression Inventory, the Beck Anxiety Inventory, the UPDRS, and a neuropsychological battery. Fifty-eight percent of subjects had moderate to severe fatigue. Fatigue was significantly associated with quality of life, depression, and anxiety. Depression preoperatively was the only predictive factor of fatigue. Fatigue is common following DBS surgery and significantly impacts quality of life.

Holmes tremor is characterized by irregular resting, postural and intention tremors. Deep brain stimulation (DBS) is an effective treatment. A 34-year-old man with Holmes tremor, secondary to head trauma, became agitated during DBS performed under local anesthesia. Remifentanil 0.03 µg/kg/min provided effective sedation and DBS was safety and successful performed. J Curr Surg. 2015;5(4):207-208 doi: http://dx.doi.org/10.14740/jcs288e

Objectives. To perform a preliminary cost-utility and cost-benefit of deep brain stimulation (DBS) in the treatment of dystonia, Materials and Methods. We conducted a prospective study of 26 patients undergoing DBS for the treatment of dystonia. We performed a cost-utility analysis using the Euroquol (EQ-5D) questionnaire. A cost-benefit analysis used the willingness-to-pay principle and costs of treatment were calculated retrospectively in order to calculate the cost-benefit. Results. We found that the EQ-5D score improved from 29 to 76.2 points after surgery, an incremental utility of 0.47. There was an overall gain of 0.94 quality-adjusted life-years (QALY) with a cost of £33,980 per QALY. Conclusions. DBS for dystonia, while an expensive treatment, compares favorably to therapies that are commonly used for other conditions.

Researchers have consistently observed in right-handed individuals across normal and disease states that the 'dominant' left hemisphere has greater ipsilateral control of the left side than the right hemisphere has over the right. We sought to determine whether this ipsilateral influence of the dominant hemisphere reported in Parkinson's disease extends to treatments such as deep brain stimulation (DBS) and whether it affects outcome. We hypothesised that among Parkinson right-handers, unilateral left DBS would provide greater ipsilateral motor improvement compared with the ipsilateral motor improvement experienced on the right side.A total of 73 Parkinson patients who underwent unilateral DBS of the subthalamic nucleus (STN) or globus palidus internus (GPi) participated. Left and right 'composite scores', were computed by separately adding all items on the left and right side from the motor section of the Unified Parkinson Disease Rating Scale. The change in the pre- and 4-month post-implantation score was the primary outcome measure. The mean motor scores improved by 4.96 ± 11.79 points (p 0.001) post-surgery on the ipsilateral side of the DBS implantation. Regression analyses revealed that the side (left vs. right) and target (STN vs. GPi) did not significantly contribute in the effect of ipsilateral motor improvement (p = 0.3557).While DBS on the 'dominant' left side failed to exert a greater ipsilateral influence compared with DBS on the non-dominant right side, significant ipsilateral motor improvements were observed after unilateral stimulation regardless of site of implantation and laterality.

BACKGROUND Accurate placement of a probe to the deep regions of the brain is an important part of neurosurgery. In the modern era, magnetic resonance image (MRI)-based target planning with frame-based stereotaxis is the most common technique. OBJECTIVE To quantify the inaccuracy in MRI-guided frame-based stereotaxis and to assess the relative contributions of frame movements and MRI distortion. METHODS The MRI-directed implantable guide-tube technique was used to place carbothane stylettes before implantation of the deep brain stimulation electrodes. The coordinates of target, dural entry point, and other brain landmarks were compared between preoperative and intraoperative MRIs to determine the inaccuracy. RESULTS The mean 3-dimensional inaccuracy of the stylette at the target was 1.8 mm (95% confidence interval [CI], 1.5-2.1. In deep brain stimulation surgery, the accuracy in the x and y (axial) planes is important; the mean axial inaccuracy was 1.4 mm (95% CI, 1.1-1.8). The maximal mean deviation of the head frame compared with brain over 24.1 ± 1.8 hours was 0.9 mm (95% CI, 0.5-1.1). The mean 3-dimensional inaccuracy of the dural entry point of the stylette was 1.8 mm (95% CI, 1.5-2.1), which is identical to that of the target. CONCLUSION Stylette positions did deviate from the plan, albeit by 1.4 mm in the axial plane and 1.8 mm in 3-dimensional space. There was no difference between the accuracies at the dura and the target approximately 70 mm deep in the brain, suggesting potential feasibility for accurate planning along the whole trajectory.

Background: The use of checklists to reduce error rates in procedural literature has led our group to employ this strategy during deep brain stimulation (DBS) surgery. Objectives: We sought to examine the improvement in the number of errors made during DBS surgery after long-term use of a checklist. Methods: Our checklist has been used for all DBS cases at our institution since the beginning of this study’s enrollment in 2008. The number of cases in which errors were detected after 1 year of routine use (group B, n = 11) was compared in one cohort of DBS subjects to that of an earlier cohort of patients (group A, n = 17), which underwent DBS exactly 1 year prior. Results: Eleven of the 14 cases where major errors were detected occurred in group A; 6 of the 9 cases where only minor errors were detected were also in group A; of the patients without any error, all 5 were in group B. We found a significant difference in these proportions between group A and group B [χ2(2) = 9.73; p < 0.008]. Conclusions: After 1 year of checklist use, the total number of major and minor errors made was reduced, indicating an improvement in error rate after long-term routine incorporation of this checklist.

Comment on "Appropriate MRI sequences are required to accurately determine lead location after deep brain stimulation surgery"

Editors' Note: Dr. Barrett et al. and author Willis discuss the limitations associated with using Medicare data in Parkinson disease research. Drs. Jung Henson and Cavalier disagree with some of the views presented in author Langer-Gould's editorial, “The pill times 2: What every woman with multiple sclerosis should know,” specifically as to the existence of human data into the teratogenicity of teriflunomide and the recommendation to stop the medication 2 years prior to conception. Author Langer-Gould responds with a discussion of the study in question and a review of the elimination methods for teriflunomide. —Megan Alcauskas, MD, and Robert C. Griggs, MD As Willis et al. recognized, one of the major limitations of Medicare data are …

Deep brain stimulation is a well-established surgical treatment for patients with movement disorders. Adverse events, such as hardware infections, are well known, but intracerebral infections are extremely rare, and can develop both shortly after surgery and after several months. We present one case of intracerebral infection after deep brain stimulation surgery, and a short review of the literature.

Publisher Summary This chapter reviews the surgical options for treating Parkinson's disease (PD) and summarizes the indications, anatomical targets, and surgical techniques. The relevant anatomy and pathophysiology and the proposed mechanisms of action of deep brain stimulation (DBS) are discussed. The evidence supporting the use of surgical therapy for PD is discussed. The focus of this chapter is on DBS as it is currently the most commonly used modality in movement-disorder surgery. Before the development of DBS, lesioning procedures were the standard surgical approach to treat movement disorders. The purpose of DBS is to disrupt the abnormal neuronal activity underlying PD and reestablish more normal motor function. Surgical therapy for PD has developed from an understanding of the functional neuroanatomy of the cortical-basal ganglia–thalamic-cortical circuit and the pathophysiology of movement disorders. The chapter discusses the mechanism of action and operative procedure of DBS, intraoperative electrophysiological mapping, and complications and adverse effects of deep brain stimulation surgery. Surgical therapy for PD has made significant advances with the emergence of DBS. A substantial proportion of levodopa-responsive PD patients may benefit from adjunctive therapy with DBS. The primary DBS targets for PD are the subthalamic nucleus (STN), globus pallidus (GPi), and ventral intermediate nucleus of the thalamus (Vim). Because of its adjustability and reversibility, DBS can be tailored to optimize its effects for each patient. To realize the potential benefits of DBS for PD, an experienced and knowledgeable team of movement disorder specialists is necessary.

A 24-year-old male patient with refractory Tourette syndrome was treated with deep brain stimulation (DBS) and developed subsequent bilateral subcortical haematomas. Additional blood tests revealed abnormalities of plasma factor XIIIA and tryptophan levels, which may be associated with Tourette syndrome. Neurosurgeons who perform DBS surgery on patients with Tourette syndrome must be aware of possible disastrous complications resulting from factor XIIIA disorders of blood haemostasis. Routine screening for this condition is not typically performed prior to surgery in these patients.

Aims: Infection of hardware is a serious complication after deep brain stimulation (DBS), as this may result in additional surgery, cost and loss of treatment benefit for the patient. We report the incidence and management of infections after DBS in a single institution over the past 11 years. Methods: A database of 270 patients with 484 implants was used in the study. Incidence, clinical characteristics and management of infections were analyzed. Results: The overall infection rate was 9.3% (25/270) by patients and 6.8% (33/484) by episode/implants. The median time of infection after implantation was 64 days. Only 7/33 episodes (21.2%) occurred within 30 days after surgery, 22/33 episodes (66.7%) within 6 months and 28/33 episodes (84.8%) within 12 months. There was no age difference between infected and noninfected patients, while comorbidities were more frequent in the former. Infection rates before and after January 2003 were 14.3 and 4.9%, respectively. The rate of complete and partial hardware salvage was 30.3 and 21.2% while that of complete hardware removal was 48.5%. Patients with deep purulent infections and patients with Staphylococcus aureus as the causative organism were more likely to have their hardware removed. Conclusions: The incidence of hardware infections declined significantly over time. Improvements in hardware and implantation techniques may be responsible. Hardware can often be completely or partly saved in infected patients.

In the recent past many groups have tried to build functional atlases of the deep brain using intra-operatively acquired information such as stimulation responses or micro-electrode recordings. An underlying assumption in building such atlases is that anatomical structures do not move between pre-operative imaging and intra-operative recording. In this study, we present evidences that this assumption is not valid. We quantify the effect of brain shift between pre-operative imaging and intra-operative recording on the creation of functional atlases using intra-operative somatotopy recordings and stimulation response data.A total of 73 somatotopy points from 24 bilateral subthalamic nucleus (STN) implantations and 52 eye deviation stimulation response points from 17 bilateral STN implantations were used. These points were spatially normalized on a magnetic resonance imaging (MRI) atlas using a fully automatic non-rigid registration algorithm. Each implantation was categorized as having low, medium or large brain shift based on the amount of pneumocephalus visible on post-operative CT. The locations of somatotopy clusters and stimulation maps were analyzed for each category.The centroid of the large brain shift cluster of the somatotopy data (posterior, lateral, inferior: 3.06, 11.27, 5.36 mm) was found posterior, medial and inferior to that of the medium cluster (2.90, 13.57, 4.53 mm) which was posterior, medial and inferior to that of the low shift cluster (1.94, 13.92, 3.20 mm). The coordinates are referenced with respect to the mid-commissural point. Euclidean distances between the centroids were 1.68, 2.44 and 3.59 mm, respectively for low-medium, medium-large and low-large shift clusters. We found similar trends for the positions of the stimulation maps. The Euclidian distance between the highest probability locations on the low and medium-large shift maps was 4.06 mm.The effect of brain shift in deep brain stimulation (DBS) surgery has been demonstrated using intra-operative somatotopy recordings as well as stimulation response data. The results not only indicate that considerable brain shift happens before micro-electrode recordings in DBS but also that brain shift affects the creation of accurate functional atlases. Therefore, care must be taken when building and using such atlases of intra-operative data and also when using intra-operative data to validate anatomical atlases.

Deep brain stimulation (DBS) is an established treatment for Parkinson’s disease and related movement disorders. The success of DBS is highly dependent on electrode location, electrical parameter settings and the surgical procedure. In this paper an overview of the current status of optical measurements for intracerebral guidance performed during DBS implantation is presented. Laser Doppler perfusion monitoring and/or reflection spectroscopy measurements have been done in relation to more than 70 DBS lead implantations to wards targets in the deep brain structures. The techniques have also been compared with impedance monitoring, and simulation of the measurement depth has been done with Monte Carlo technique. These studies show that grey-white matter boundaries can be determined with a resolution higher than for both impedance measurements and magnetic resonance imaging. Original Publication: Karin Wårdell, Johannes Johansson, Johan Richter and Patric Blomstedt, Optical measurements for guidance during deep brain stimulation surgery, 2009, World Congress on Medical Physics and Biomedical Engineering, 516-517. http://dx.doi.org/10.1007/978-3-642-03889-1 Copyright: Springer http://www.springerlink.com/

Deep brain structures are frequently used as targets in neurosurgical procedures. However, the boundaries of these structures are often not visible in clinically used MR and CT images. Techniques based on anatomical atlases and indirect targeting are used to infer the location of these targets intraoperatively. Initial errors of such approaches may be up to a few millimeters, which is not negligible. E.g. subthalamic nucleus is approximately 4x6 mm in the axial plane and the diameter of globus pallidus internus is approximately 8 mm, both of which are used as targets in deep brain stimulation surgery. To increase the initial localization accuracy of deep brain structures we have developed an atlas-based segmentation method that can be used for the surgery planning. The atlas is a high resolution MR head scan of a healthy volunteer with nine deep brain structures manually segmented. The quality of the atlas image allowed for the segmentation of the deep brain structures, which is not possible from the clinical MR head scans of patients. The subject image is non-rigidly registered to the atlas image using thin plate splines to represent the transformation and normalized mutual information as a similarity measure. The obtained transformation is used to map the segmented structures from the atlas to the subject image. We tested the approach on five subjects. The quality of the atlas-based segmentation was evaluated by visual inspection of the third and lateral ventricles, putamena, and caudate nuclei, which are visible in the subject MR images. The agreement of these structures for the five tested subjects was approximately 1 to 2 mm.

Reversible changes in subthalamic nucleus (STN) activity, detected by microelectrode recording (MER), are reported in three patients who received an intravenous betablocker, metoprolol, during deep brain stimulation (DBS) for Parkinson's disease (PD).Metoprolol (MP) was given intravenously to reduce blood pressure during surgery. Systolic blood pressure dropped by 4, 11 and 17%, indicating a systemic beta - adrenoceptor blocking effect.In all patients, the bursting spiking activity of the STN was temporarily suppressed, after the application of MP. Unexpectedly, a transient reduction in Parkinson symptoms (rigidity) was recorded during suppression of STN spiking activity in patient 2.The reversible suppression of STN activity and Parkinson symptoms with the beta1-selective adrenoceptor antagonist MP has not been reported. It supports the theory, that--as recently reported in the rat--the human STN is influenced by adrenergic inputs. This report supports the possible application of adrenergic antagonist drugs for the use in Parkinson's disease and advocates additional neurophysiological and pharmacological research in this field.

Deep brain stimulation (DBS) represents one of the more recent advancements in Neurosurgery. Even though its most successful applications evolved in movement disorders (MDs), indications now include pain, psychiatric disorders, epilepsy, cluster headaches and Tourette syndrome. As this type of surgery gains popularity and the indications for DBS surgery increase, so it will certainly increase the number of neurosurgeons who will use this neuromodulatory technique. A detailed description of the technical aspects of the DBS procedure, as it is performed in our department, is presented. In our opinion, our method is a good combination of all the well-established necessary techniques in a cost-effective way. This technical article may be helpful to neurosurgeons considering to start performing this type of surgery. It could also prompt others who perform DBS regularly to express their views, and hence, lead to further refinement of this demanding procedure.

Deep brain stimulation (DBS) surgery is a treatment for patients suffering from Parkinson's disease and other movement disorders. The success of the procedure depends on the implantation accuracy of the DBS electrode array. Surgical planning and navigation are done based on the pre-operative patient scans, assuming that brain tissues do not move from the time of the pre-operative image acquisition to the time of the surgery. We performed brain shift analysis on nine patients that underwent DBS surgery using a 3D non-rigid registration algorithm. The registration algorithm automatically aligns the pre-operative and the post-operative 3D MRI scans and provides the shift vectors over the entire brain. The images were first aligned rigidly and then non-rigidly registered with an algorithm based on thin plate splines and maximization of the normalized mutual information. Brain shift of up to 8 mm was recorded in the nine subjects, which is significant given that the size of the targets in the DBS surgery is a few millimeters.

International audience; Numerous factors need to be taken into account when implanting deep brain stimulation (DBS) systems into patients with Parkinson's disease. The surgical procedure itself can be divided into immediate preoperative, intraoperative, and immediate postoperative phases. Preoperative considerations include medication withdrawal issues, stereotactic equipment choices, imaging modalities, and targeting strategy. Intraoperative considerations focus on methods for physiological confirmation of a given target for DBS electrode deployment. Terms such as microelectrode recording, microstimulation, and macrostimulation will be defined to clarify inconsistencies in the literature. Advantages and disadvantages of each technique will be addressed. Furthermore, operative decisions such as staging, choice of electrode and implantable pulse generator, and methods of device fixation will be outlined. Postoperative issues include imaging considerations, including magnetic resonance safety, device-device interactions, and immediate surgical complications pertaining to the DBS procedure. This report outlines answers to a series of questions developed to address all aspects of the DBS surgical procedure and decision-making with a systematic overview of the literature (until mid-2004) and by the expert opinion of the authors. This is a report from the Consensus on Deep Brain Stimulation for Parkinson's Disease, a project commissioned by the Congress of Neurological Surgeons and the Movement Disorder Society. It outlines answers to a series of questions developed to address all surgical aspects of deep brain stimulation.

In our center, a physiotherapist is present in the operative room to bring relief to the Parkinsonian patient during subthalamic nucleus stimulation surgery under local anesthesia. This study searched to determine the causes of pain and suffering during bilateral electrode implantation and to assess the role of physiotherapy. Ninety-two consecutive patients operated on between 2001 and 2004 were included in this retrospective study. A questionnaire with eight items was developed and mailed to the patients. Seventy-five responses to questionnaires were available. All patients except one experienced physical pain and psychological suffering, alleviated by physiotherapy. These preliminary results need to be confirmed in a prospective randomized study.

Deep brain stimulation (DBS) surgery can significantly improve the quality of life for patients suffering from movement disorders, but the outcome of the surgery greatly depends on the implantation accuracy of the deep brain stimulator. A few millimeter shift in the mid-brain region can influence the results because the pre-operative planning is based on the assumption that anatomical structures do not move between the pre-operative image scan time and the time of the surgery. We studied 15 cases of DBS surgery for possible brain shift between the pre-operative and the post-operative 3D MRI scans. Brain shift of up to 3.8 mm was measured after rigidly aligning the pre-operative images with the post-operative images. The rigid registration algorithm has sub-voxel accuracy (registration error of less than 1 mm), and it automatically recovers any rotation around the three axes along with significant translations in the three directions. The brain shift measurements were compared to relevant intra and post operative parameters.

A retrospective chart review characterizing changes in 17 male and 10 female Parkinson's disease (PD) patients undergoing deep brain stimulation (DBS) surgery indicated that 6 mo before surgery, patients lost a mean of 5.1 lbs, whereas in the 6 mo after surgery, subjects gained a mean of 10.1 lbs; 22% gained more than 14 lbs. In 10 patients followed an additional 6 mo, weight gain continued. This weight gain may be associated with decreased energy expenditure due to subsidence of chronic tremor. The magnitude of gain underscores the need for proactive management of body weight in PD patients undergoing DBS.

The factions of functional neurosurgeons performing deep brain stimulation (DBS) for movement disorders are fairly well separated. The physiology aficionados subscribe to the doctrine that only meticulous microelectrode recording (MER) in the awake patient without any sedative interference gives optimal results. The believers in the accuracy of imaging claim that targeting the subthalamic nucleus (STN) the globus pallidum internus can be achieved precisely from MRI or MR/CT fusion alone with equally good outcomes as measured on the Unified Parkinson's Disease Rating Scale (UPDRS) and the ability to postoperatively cut the Levodopa (L-DOPA) equivalent amount of medication. Fluchere and colleagues seem to have found a Salomonic compromise that could satisfy both camps.1 In an impressively large cohort of 126 patients they used ‘controlled …