Dual-floor Burr Hole Technique Optimized for Modern Burr Hole Caps with an Internal Electrode Locking Mechanism

Insertion of a deep brain stimulating electrode is a commonly performed procedure. Burr hole caps play an important role in this procedure by immobilizing this electrode; however, burr hole caps could form scalp bumps, which can create further complications. The dual-floor burr hole technique could prevent the formation of scalp bumps. This technique has previously been used with older versions of burr hole caps and has proved to be successful. In recent years, modern burr hole caps with an internal electrode locking mechanism have become the mainstay for this procedure. However, modern burr hole caps differ considerably in diameter and shape from older burr hole caps. In the present study, a dual-floor burr hole technique was performed using modern burr hole caps. To accommodate the increase in diameters and changes in the shape of modern burr hole caps, a perforator with a 30-mm diameter was used for shaving the bone, and the bone shaving depth was altered. This surgical technique was applied to 23 consecutive deep brain stimulation surgeries without complications and was thus positively optimized for modern burr hole caps.

An antibiotic envelope to reduce infections in deep brain stimulation surgery

The therapeutic benefits of Deep Brain Stimulation (DBS) surgery in patients with movement disorderssuch as Parkinson's Diseaseare life-altering. Surgical site infections (SSI), however, can result in increasedhospitalisations, prolonged antibiotics and neurological sequelae. We performed aretrospective review to evaluate the effectiveness of an antibiotic envelope to reduce SSI in DBS surgeries.This study includedall DBS surgeries performed between August 2020 to May 2022 using a single-use, multifilament, antibiotic-coated mesh envelope wrapped around the DBS implantable pulse generator (IPG)(TYRX™ Absorbable Antibacterial Envelope,Medtronic Fridley, MN, USA). Standardised infection-prevention measures were applied and various patient-specific and surgery-specific factors were analysed.44 patients were analysed with 26 (59.1 %) primary implantations and 18 (40.9 %) revision surgeries.The median age was 65 years old with an average follow-up of 13.5 months (range 3-24 months). The mean Body Mass Indexwas 24.0 (range 16.7-35.6). 8 (18.2 %) patients had underlying diabetes mellitus. There were only 2 (4.5 %) SSIs reported with neither involvingthe subcutaneous IPG and antibiotic envelope. 1 superficial-incisional SSI (2.3 %) was from a prior retro-auricular abscess around a lead-wirerequiring antibiotics and subcutaneous implanttransposition. The other was a deep-incisional SSI (2.3 %) from repetitive trauma causingdelayed scalp wound dehiscence and lead-wire extrusion, requiring antibiotics and wound revision. Both subjects were discharged well with no implants removed. Theantibioticenvelope therefore appears to be a safe and well-tolerated adjunct that may reduce SSIs in DBS surgery. Further prospective work withlarger sample sizes in a multi-institution setting is required.

Prevention and Treatment of Hardware-Related Infections in Deep Brain Stimulation Surgeries: A Retrospective and Historical Controlled Study

Background

Hardware-related infection in deep brain stimulation (DBS) is one of the most commonly reported complications frequently resulting in the removal of implantable pulse generator (IPG).

Objective

The aim of this study was to establish a useful strategy to better prevent and treat those infections and to improve the preservation rates of IPG.

Methods

We conducted a retrospective and historical controlled study of all adult patients (≥18 years old) who had undergone initial DBS implantation at a single center. All participants were enrolled in the control group (between June 2005 and June 2014) or intervention group (between July 2014 and May 2019) based on their surgery dates. We used the intraoperative irrigation with hydrogen dioxide solution in the intervention group. Based on the dates of diagnosis, patients with hardware-related infection after DBS were enrolled in group A (between June 2005 and June 2014) or group B (between July 2014 and May 2019). IPG-sparing algorithm (Isa) was applied for group B. The early-onset IPG infections of the control and intervention groups were evaluated. The IPG preservation rates in both groups A and B were statistically analyzed.

Results

Six cases of early IPG infection and subsequent IPG removal occurred in the control group, while none occurred after intraoperative usage of the hydrogen dioxide in the intervention group. IPG preservation rate of infected cases in group B was significantly higher than that in group A (70% vs.16%, p = 0.004).

Conclusion

The combined application of hydrogen dioxide solution and Isa seems to be an effective strategy to prevent IPG infection.

Solvent-Free Strategy To Encapsulate Degradable, Implantable Metals in Silk Fibroin

Implantable electronics hold enormous clinical potential for diagnosis and treatment of neurodegenerative and cardiac diseases and abnormalities. Transient devices are attractive alternatives to conventional silicon electrodes, as they can provide short-term electrical stimulation/recording followed by complete device degradation, mitigating the need for removal surgeries. Packaging transient metals is inherently challenging as they degrade upon contact with aqueous conditions. Development of new transient metal packaging strategies is a critical step toward transient device development. In this fundamental work, a solvent-free compression molding approach to encapsulate magnesium, a resorbable metal, in silk fibroin protein is reported. Silk fibroin was selected because of its processing versatility, desirable mechanical properties, compatibility with biological environments, and controllable degradation behavior in aqueous environments. The silk/magnesium composites were fabricated via compression molding, followed by water annealing to modify the secondary structure of the silk protein matrix to tune physical properties. Transient composite properties as a function of water annealing time are presented, which elucidate synergies between silk physical properties and degradation kinetics of the encapsulated magnesium, information useful in the design of multifunctional, transient metal-based constructs.

Deep brain stimulation for psychiatric disorders

BACKGROUND

Deep brain stimulation (DBS), an established treatment for some movement disorders, is now being used experimentally to treat psychiatric disorders as well. In a number of recently published case series, DBS yielded an impressive therapeutic benefit in patients with medically intractable psychiatric diseases.

METHODS

This review of the use of DBS to treat psychiatric disorders is based on literature retrieved from a selective Pubmed search for relevant keywords, reference works on the topic, and the authors' own research.

RESULTS

Studies have been performed on the use of DBS to treat medically intractable obsessive-compulsive disorder, depressive disorders, and Tourette syndrome. The case numbers in the cited publications were small, yet at least some of them involved a methodologically sound investigation. Thus, in some studies, the strength of the effect was controlled with a double-blinded interval in which the stimulation was turned off. In general, the primary symptoms were found to improve markedly, by 35% to 70%, although not all patients responded to the treatment. Adverse effects of DBS were very rare in most studies and could usually be reversed by changing the stimulation parameters.

CONCLUSIONS

The results of DBS for psychiatric disorders that have been published to date are encouraging. They open up a new perspective in the treatment of otherwise intractable disorders. Nonetheless, the efficacy, mechanism of action, and adverse effects of DBS for this indication still need to be further studied in methodologically adequate trials that meet the highest ethical standard.

Bilateral deep brain stimulation in Parkinson's disease: a multicentre study with 4 years follow-up

Deep brain stimulation (DBS) is associated with significant improvement of motor complications in patients with severe Parkinson's disease after some 6-12 months of treatment. Long-term results in a large number of patients have been reported only from a single study centre. We report 69 Parkinson's disease patients treated with bilateral DBS of the subthalamic nucleus (STN, n = 49) or globus pallidus internus (GPi, n = 20) included in a multicentre study. Patients were assessed preoperatively and at 1 year and 3-4 years after surgery. The primary outcome measure was the change in the 'off' medication score of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III) at 3-4 years. Stimulation of the STN or GPi induced a significant improvement (50 and 39%; P < 0.0001) of the 'off' medication UPDRS-III score at 3-4 years with respect to baseline. Stimulation improved cardinal features and activities of daily living (ADL) (P < 0.0001 and P < 0.02 for STN and GPi, respectively) and prolonged the 'on' time spent with good mobility without dyskinesias (P < 0.00001). Daily dosage of levodopa was significantly reduced (35%) in the STN-treated group only (P < 0.001). Comparison of the improvement induced by stimulation at 1 year with 3-4 years showed a significant worsening in the 'on' medication motor states of the UPDRS-III, ADL and gait in both STN and GPi groups, and speech and postural stability in the STN-treated group. Adverse events (AEs) included cognitive decline, speech difficulty, instability, gait disorders and depression. These were more common in patients treated with DBS of the STN. No patient abandoned treatment as a result of these side effects. This experience, which represents the first multicentre study assessing the long-term efficacy of either STN or GPi stimulation, shows a significant and substantial clinically important therapeutic benefit for at least 3-4 years in a large cohort of patients with severe Parkinson's disease.