Dianyou Li

Deep-Brain Stimulation for Anorexia Nervosa

OBJECTIVE Anorexia nervosa (AN) is a complex and severe, sometimes life-threatening, psychiatric disorder with high relapse rates under standard treatment. After decades of brain-lesioning procedures offered as a last resort, deep-brain stimulation (DBS) has come under investigation in the last few years as a treatment option for severe and refractory AN. METHODS AND RESULTS In this jointly written article, Sun et al. (the Shanghai group) report an average of 65% increase in body weight in four severe and refractory patients with AN after they underwent the DBS procedure (average follow-up: 38 months). All patients weighed greater than 85% of expected body weight and thus no longer met the diagnostic criteria of AN at last follow-up. Nuttin et al. (the Leuven group) describe other clinical studies that provide evidence for the use of DBS for AN and further discuss patient selection criteria, target selection, and adverse event of this evolving therapy. CONCLUSION Preliminary results from the Shanghai group and other clinical centers showed that the use of DBS to treat AN may be a valuable option for weight restoration in otherwise-refractory and life-threatening cases. The nature of this procedure, however, remains investigational and should not be viewed as a standard clinical treatment option. Further scientific investigation is essential to warrant the long-term efficacy and safety of DBS for AN.

Effect of welding energy on interface zone of Al–Cu ultrasonic welded joint

Abstract Ultrasonic welding is attracting increasing attentions in joining of dissimilar materials. The effect of welding energy on joint strength, failure behaviour and microstructure of Al–Cu ultrasonic welded joint has been experimentally investigated. The results showed that joint strength increased with welding energy initially and reached its maximum at 1000 J, then dropped significantly instead. Meanwhile, the failure mode changed from interfacial debonding to nugget pullout, and then back to cleavage failure. Various microstructures with different morphologies and properties were also observed at the interfacial region. At lower energy, the joint was only partly bonded by numbers of dispersed microbonds. A swirl-like structure appeared at the weld interface and led to a mechanical interlocking between the materials at higher energies (∼1000 J). However, cavity defects and intermetallic compound (IMC) were more likely to form under excessively high energies. A 0·5 μm thick IMC layer with dominant phase of Al4Cu9 was found in 2000 J joint.

Subthalamus deep brain stimulation for primary dystonia patients: a long-term follow-up study.

Deep brain stimulation has generated sustained improvement in motor function for patients with dystonia, but the long‐term impact of subthalamic nucleus stimulation on dystonia has not been elucidated.

Resting state cortical oscillations of patients with Parkinson disease and with and without subthalamic deep brain stimulation: a magnetoencephalography study.

Purpose: In this study, we investigate the modification to cortical oscillations of patients with Parkinson disease (PD) by subthalamic deep brain stimulation (STN-DBS). Methods: Spontaneous cortical oscillations of patients with PD were recorded with magnetoencephalography during on and off subthalamic nucleus deep brain stimulation states. Several features such as average frequency, average power, and relative subband power in regions of interest were extracted in the frequency domain, and these features were correlated with Unified Parkinson Disease Rating Scale III evaluation. The same features were also investigated in patients with PD without surgery and healthy controls. Results: Patients with Parkinson disease without surgery compared with healthy controls had a significantly lower average frequency and an increased average power in 1 to 48 Hz range in whole cortex. Higher relative power in theta and simultaneous decrease in beta and gamma over temporal and occipital were also observed in patients with PD. The Unified Parkinson Disease Rating Scale III rigidity score correlated with the average frequency and with the relative power of beta and gamma in frontal areas. During subthalamic nucleus deep brain stimulation, the average frequency increased significantly when stimulation was on compared with off state. In addition, the relative power dropped in delta, whereas it rose in beta over the whole cortex. Through the course of stimulation, the Unified Parkinson Disease Rating Scale III rigidity and tremor scores correlated with the relative power of alpha over left parietal. Conclusions: Subthalamic nucleus deep brain stimulation improves the symptoms of PD by suppressing the synchronization of alpha rhythm in somatomotor region.

Subthalamic nucleus deep brain stimulation for Parkinson's disease: 8 years of follow-up.

ObjectiveThe short-term benefits of bilateral stimulation of the subthalamic nucleus (STN) in patients with advanced Parkinson’s disease (PD) are well documented, but long-term benefits are still uncertain. The aim of this study is to evaluate the outcome of 8 years of bilateral STN stimulation to PD patients.MethodsIn this study, 31 consecutive PD patients were treated with bilateral STN stimulation. Their functional status was measured using the Activities of Daily Living section of the Unified Parkinson’s Disease Rating Scale (UPDRS-ADL) at drug on (with medication) and drug off (without medication) states preoperatively and at 1, 5, and 8 years postoperatively. In addition, Levodopa equivalent doses and stimulation parameters were also assessed.ResultsAfter 8 years of STN stimulation, the UPDRS-ADL scores were improved by 4% at drug off status (P > 0.05) and 22% at drug on status (P < 0.05) compared with baseline; the levodopa daily doses were reduced by 28% (P < 0.05) compared with baseline; the stimulation voltage and pulse width were not changed, but the stimulation frequency was decreased remarkably compared with the 5 years of follow-up. Adverse events were observed in 6 patients, including misplacement of the electrode and skin erosion requiring further surgery. All events were resolved without permanent sequelae. 2 patients died of aspiration pneumonia 6 and 7 years after surgery.ConclusionsThe marked improvement in UPDRS-ADL scores were still observed after 8 years of bilateral STN stimulation with medication.

Long-Term Follow-Up of MRI-Guided Bilateral Anterior Capsulotomy in Patients with Refractory Schizophrenia

Aim: To determine whether there is a long-term benefit of MRI-guided bilateral anterior capsulotomy in the treatment of refractory schizophrenia. Methods: 116 patients (16 patients did not complete the follow-up evaluation) with refractory schizophrenia who underwent capsulotomy were included. The treatment effect was evaluated using a series of international rating scales. Evaluations were performed at baseline, 3 weeks and 24 months after surgery. Results: The rate of effectiveness was 74% according to the Clinical Global Impression evaluation, and there was an obvious improvement based on the statistical analysis for Positive and Negative Symptom Scale (baseline vs. 24 months after surgery, 6.86 ± 8.12, 10.70 ± 8.70 vs. 26.65 ± 4.85, 21.66 ± 7.19), Brief Psychiatric Rating Scale (14.75 ± 13.21 vs. 44.97 ± 9.36), Activities of Daily Living Scale (18.06 ± 6.58 vs. 24.61 ± 8.95), Social Disability Screening Schedule (6.69 ± 6.12 vs. 15.06 ± 3.18) and Global Assessment Scale (74.35 ± 12.75 vs. 48.74 ± 9.18). Among all the symptoms of schizophrenia, aggressive behavior (82% response rate), hallucination, (71% response rate) and delusion (70% response rate) showed the best response. Conclusion: Our research indicates that capsulotomy is a relatively safe and effective intervention for patients with refractory schizophrenia. It could be an alternative therapy for those patients with chronic and severe schizophrenia. But there must be strict inclusion criteria considering the complications and irreversibility of this procedure.

Relay assignment and cooperation maintenance in wireless networks: a game theoretical approach

In this study, the authors study the relays assignment problem in cooperative wireless networks with self-interested nodes. The authors propose a cooperation mechanism which includes the cooperative relationship formation stage and cooperation maintenance stage. The cooperative relationship among the nodes can be modelled as an exchange market game where nodes trade transmission power between each other to obtain diversity gain. The exchange games have a basic assumption that each node conforms to trade agreement so that each agent has the option to trade its good to obtain a better one. In such a game, strict core is considered as individual rational, Pareto optimal and relationship-stable solution. A cooperation cycle formation (CCF) algorithm is proposed to obtain the strict core solution. However, in networks, some deviated nodes may break the cooperation agreement to obtain more utility gain. Such deviated behaviours in the cooperation cycles can totally destroy the cooperation relationship. However, the data transmissions in networks have the repeated element. Hence, based on the cooperative cycle formed by CCF, the authors introduce a repeated game model for cooperation maintenance in the second stage. A dynamic punishment and recover mechanism is proposed to punish the deviated behaviours and recover cooperation.

Modulations on cortical oscillations by subthalamic deep brain stimulation in patients with Parkinson disease: A MEG study

OBJECTIVE The study aimed to explore the modification to cortical oscillations of Parkinson disease (PD) patients by subthalamic nucleus deep brain stimulation (STN DBS). METHODS With Magnetoencephalogram (MEG) detection, we examined the changes in absolute power spectrum of cortical oscillations in the PD patients with the treatment of STN DBS. RESULTS The power analysis of PD patients showed a dominant over-synchronization of alpha and beta bands in temporal and occipital areas relative to the healthy control subjects. STN DBS on-state showed marked power increase in the gamma band of PD patients in the frontal and parietal relative to the DBS off-state. The alleviation of motor symptoms by STN DBS negatively correlated to the increase of high gamma oscillation in the right frontal cortex, and also correlated to the suppression of the alpha and beta oscillations in the right temporal cortex. CONCLUSION The treatment of STN DBS to PD patients might involve the augmentation of gamma activity and suppression of alpha and beta activities in cortical oscillations.

A Remote and Wireless Deep Brain Stimulation Programming System.

To the Editor: The success of deep brain stimulation generally depends on a good grasp of surgical indications, precise implantation of electrodes, and the optimal adjustment of programmable parameters (1). Programming settings are modified through contact selection, pulse width, frequency, and amplitude, to achieve optimal control of clinical symptoms with minimal stimulation parameters. Hence, programming is a crucial aspect of DBS, which directly influences its therapeutic efficacy (2). DBS patients are typically required to undergo three stages of programming: intraoperative, initial postoperative, and follow-up postoperative. Intraoperative programming is intended to test the physical connectivity (impedance) of the DBS system and the clinical efficacy of DBS, thereby providing indirect evidence of accurate electrode placement (3,4). The goal of initial postoperative programming is to identify the minimal stimulation parameters needed to achieve optimal control of clinical symptoms. The purpose of followup postoperative programming is to perform appropriate adjustments to stimulation parameters according to changes in the patient’s condition, including disease progression and suboptimal symptom control due to medication adjustments. Different programming requirements exist at different programming stages. Intraoperative programming time should be minimized to reduce total operation time, while the surgical procedure should be adapted to minimize risk of infection caused by programming. For initial postoperative programming, the time needed to ascertain optimum stimulation parameters should also be minimized, and reasonable arrangement of numerous patients’ programming schedules must be organized. Finally, follow-up postoperative programming should maximize patient convenience by reducing the time and financial cost of travelling between the patient’s home and the hospital. There are a number of inadequacies in conventional programming methods. First, the programming probe must come into close contact with the implantable pulse generator (IPG) and test stimulator to complete programming. However, the probe is not sterile during intraoperative programming and must therefore be wrapped in a sterile plastic bag before it can be attached to the IPG. Furthermore, when measuring the physical connectivity of the DBS product, the surgeon must pause the surgery and make room for the attachment between the programming probe and IPG. During initial postoperative programming, only the parameters of one patient can be ascertained. In addition, the same frequency is typically used in the left and right brain for dual channel IPG. During follow-up postoperative programming, the patient must repeatedly travel between their home and the hospital, leading to increased time and expense. An ideal solution to the outlined issues lies in wireless and remote programming technology. With this technology, the need for an additional probe is eliminated, as is the need for close contact, thus significantly reducing the risk of infection. Furthermore, all patients awaiting programming can be simultaneously identified, and programming a single patient only requires switching within the patient list. Data from multiple groups can also be stored. In addition, the technology offers remote follow-up capabilities. It is therefore convenient, time-saving, and economical for patients. To address the outlined issues, we developed the SceneRay wireless and remote DBS system. This system has significant advantages across all three stages of programming compared to conventional programming methods. Patient convenience is markedly improved, while risk of infection and total treatment time are minimized, thereby leading to an overall benefit for doctors and patients alike.

Remotely Programmed Deep Brain Stimulation of the Bilateral Subthalamic Nucleus for the Treatment of Primary Parkinson Disease: A Randomized Controlled Trial Investigating the Safety and Efficacy of a Novel Deep Brain Stimulation System.

Background: Deep brain stimulation (DBS) is the most commonly performed surgery for the debilitating symptoms of Parkinson disease (PD). However, DBS systems remain largely unaffordable to patients in developing countries, warranting the development of a safe, economically viable, and functionally comparable alternative. Objective: To investigate the efficacy and safety of wirelessly programmed DBS of bilateral subthalamic nucleus (STN) in patients with primary PD. Methods: Sixty-four patients with primary PD were randomly divided into test and control groups (1:1), where DBS was initiated at either 1 month or 3 months, respectively, after surgery. Safety and efficacy of the treatment were compared between on- and off-medication states 3 months after surgery. Outcome measures included analysis of Unified Parkinsons Disease Rating Scale (UPDRS) scores, duration of “on” periods, and daily equivalent doses of levodopa. All patients were followed up both 6 and 12 months after surgery. Results: Three months after surgery, significant decrease in the UPDRS motor scores were observed for the test group in the off-medication state (25.08 ± 1.00) versus the control group (4.20 ± 1.99). Conclusions: Bilateral wireless programming STN-DBS is safe and effective for patients with primary PD in whom medical management has failed to restore motor function.