Rechargeable Stimulators in Deep Brain Stimulation for Obsessive-Compulsive Disorder: A Prospective Interventional Cohort Study

Meta-analysis and review of rechargeable implantable pulse generators for spinal cord stimulation and deep brain stimulation

Introduction

Neuromodulation through deep brain stimulation (DBS) and spinal cord stimulation (SCS) has become a successful therapy for various neurological disorders, such as movement disorders and chronic pain. Implantable pulse generators (IPGs) are pivotal in these therapies, available as either rechargeable (r-IPGs) or non-rechargeable (nr-IPGs).

Research question

To perform a meta-analysis on r-IPGs.

Methods

A systematic literature search following PRISMA guidelines was conducted on PubMed, focusing on studies published from January 2005 to August 2023. Included studies comprised clinical trials, randomized controlled trials, and comparative studies involving human subjects. Data extraction focused on patient demographics, stimulation types, battery characteristics, and complications. Descriptive statistics and Pearson correlation analyses were performed using SPSS software.

Results

Nine studies involving 288 patients with rechargeable IPGs (r-IPGs) for SCS and 257 patients with r-IPGs for DBS met the inclusion criteria. r-IPGs exhibited low rates of surgical revisions and infections, with surgical revision rates of 8.87% for SCS and 5.45% for DBS, and infection rates of 2.6% for SCS and 1.56% for DBS. Charge burden was comparable with 97.34 min and 93.41 min per week for SCS and DBS respectively. Correlation analyses indicated that longer battery recharge times were associated with an increased incidence of complications, including unintentional interruptions and hardware failures.

Discussion

r-IPGs may offer substantial benefits in reducing re-operation rates and complications associated. Nonetheless, careful management of battery charging is crucial to maximize these benefits. Establishing international guidelines for the use of r-IPGs in specific patient populations and conditions is recommended to standardize and optimize outcomes.

The Potential Regulation of Working Anode for Long-Term Zero-Volt Storage at 37 °C in Li-Ion Batteries

The advanced lithium-ion batteries that can tolerate zero-volt storage (ZVS) are in high demand for implantable medical devices and spacecraft. However, ZVS can raise the anode potential, leading to Cu current collector dissolution and solid-electrolyte interphase (SEI) degradation, especially at 37 °C. In this contribution, by quantitatively regulating the dosage of Li6CoO4 cathode additives, controllable potential of the working anode under abusive-discharge conditions is demonstrated. The addition of Li6CoO4 keeps zero-crossing potential (ZCP) and the potential of ZVS below 2.0 V (vs Li/Li+) for LiCoO2|mesocarbon microbead cells at 37 °C. The capacity retention ratio (CRR) increases from 69.1% and 35.9% to 98.6% and 90.8% after 10 and 20 days of ZVS, respectively. The Cu dissolution and SEI degradation are effectively suppressed, while the over-lithiated cathode exhibits high reversible capacity after ZVS. The limiting conditions of long-term ZVS are further explored and a corresponding guide map is designed. When quantitatively regulating ZCP and the potential in ZVS, Cu dissolution, SEI degradation, and irreversible conversion of the cathode constitute the limiting conditions. This contribution designs the most reasonable potential range for ZVS protection at 37 °C, and realizes the best CRR record through precise potential regulation for the first time.

Recharge PSYCH: A Study on Rechargeable Implantable Pulse Generators in Deep Brain Stimulation for Psychiatric Disorders

BACKGROUND

Rechargeable implantable pulse generators (r-IPGs) for deep brain stimulation (DBS) promise longer battery life and fewer replacement surgeries versus non-rechargeable systems. Long-term data on the effects of recharging in patients who received DBS for psychiatric indications is limited. The Recharge PSYCH trial is the first study that included DBS patients with psychiatric disorders treated with different r-IPG models.

METHODS

Standardized questionnaires were sent to all psychiatric DBS patients with an r-IPG implanted at the time of the study. The primary endpoint was convenience of recharging. Secondary endpoints were rate of user confidence and rate of usage-related complications, as well as charge burden (defined as minutes per week needed to recharge).

RESULTS

Data sets of n = 21 patients were eligible for data analysis. At the time of the survey patients were implanted with the r-IPG for a mean 31.8 ± 22.4 months. Prior to being implanted with an r-IPG, patients had undergone a median of 3 IPG replacements. The overall convenience of the charging process was rated as "easy" with a median of 8.0 out of 10.0 points. 33.3% of patients experienced situations in which the device could not be successfully recharged. In 38.1% of patients, therapy with the r-IPG was interrupted unintentionally. The average charge burden was 286 ± 22.4 minutes per week.

CONCLUSIONS

Patients with psychiatric disorders rated the recharging process as "easy", but with a significantly higher charge burden and usage-related complication rates compared to published data on movement disorder DBS patients.

Long-term Outcome of Deep Brain Stimulation of the Ventral Part of the Anterior Limb of the Internal Capsule in a Cohort of 50 Patients With Treatment-Refractory Obsessive-Compulsive Disorder

BACKGROUND

Deep brain stimulation (DBS) is an effective intervention for patients with severe treatment-refractory obsessive-compulsive disorder (OCD). Our aim was to examine long-term effectiveness and tolerability of DBS and its impact on functioning and well-being.

METHODS

Fifty patients with severe treatment-refractory OCD received DBS of the ventral part of the anterior limb of the internal capsule and were followed for at least 3 years following implantation (mean 6.8 ± 3 years). Primary effectiveness was assessed by change in Yale-Brown Obsessive Compulsive Scale scores. Secondary effectiveness measures included Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale, World Health Organization Quality of Life Scale-Brief Version, Global Assessment of Functioning, and a scale assessing functioning in work, family, and social life. Adverse effects of DBS were examined with a structured interview (n = 38).

RESULTS

At long-term follow-up, OCD symptoms decreased by 39% (p < .001), and half of the patients were responders (≥35% decrease of Yale-Brown Obsessive Compulsive Scale score). Anxiety and depressive symptoms decreased significantly, with reductions of 48% and 50%, respectively. The World Health Organization Quality of Life Scale-Brief Version general score improved significantly, as did 3 of 4 subdomains. Both clinician- and patient-rated functioning improved substantially (p < .001). The unemployment rate decreased from 78% at baseline to 58% at last follow-up (z = -1.90, p = .058), and 21 patients stopped or decreased psychotropic medication (z = -2.887, p = .004). Long-term adverse effects included cognitive complaints and fatigue. Serious adverse events included 1 suicide attempt, related to comorbid depression.

CONCLUSIONS

Our results provide evidence that DBS of the ventral part of the anterior limb of the internal capsule is effective and tolerable for treatment-refractory OCD in the long term and improves functioning and overall well-being.

Deep brain stimulation for obsessive-compulsive disorder: A systematic review of worldwide experience after 20 years

BACKGROUND

Twenty years after its first use in a patient with obsessive-compulsive disorder (OCD), the results confirm that deep brain stimulation (DBS) is a promising therapy for patients with severe and resistant forms of the disorder. Nevertheless, many unknowns remain, including the optimal anatomical targets, the best stimulation parameters, the long-term (LT) effects of the therapy, and the clinical or biological factors associated with response. This systematic review of the articles published to date on DBS for OCD assesses the short and LT efficacy of the therapy and seeks to identify predictors of response.

AIM

To summarize the existing knowledge on the efficacy and tolerability of DBS in treatment-resistant OCD.

METHODS

A comprehensive search was conducted in the PubMed, Cochrane, Scopus, and ClinicalTrials.gov databases from inception to December 31, 2020, using the following strategy: “(Obsessive-compulsive disorder OR OCD) AND (deep brain stimulation OR DBS).” Clinical trials and observational studies published in English and evaluating the effectiveness of DBS for OCD in humans were included and screened for relevant information using a standardized collection tool. The inclusion criteria were as follows: a main diagnosis of OCD, DBS conducted for therapeutic purposes and variation in symptoms of OCD measured by the Yale-Brown Obsessive-Compulsive scale (Y-BOCS) as primary outcome. Data were analyzed with descriptive statistics.

RESULTS

Forty articles identified by the search strategy met the eligibility criteria. Applying a follow-up threshold of 36 mo, 29 studies (with 230 patients) provided information on short-term (ST) response to DBS in, while 11 (with 155 patients) reported results on LT response. Mean follow-up period was 18.5 ± 8.0 mo for the ST studies and 63.7 ± 20.7 mo for the LT studies. Overall, the percentage of reduction in Y-BOCS scores was similar in ST (47.4%) and LT responses (47.2%) to DBS, but more patients in the LT reports met the criteria for response (defined as a reduction in Y-BOCS scores > 35%: ST, 60.6% vs LT, 70.7%). According to the results, the response in the first year predicts the extent to which an OCD patient will benefit from DBS, since the maximum symptom reduction was achieved in most responders in the first 12-14 mo after implantation. Reports indicate a consistent tendency for this early improvement to be maintained to the mid-term for most patients; but it is still controversial whether this improvement persists, increases or decreases in the long term. Three different patterns of LT response emerged from the analysis: 49.5% of patients had good and sustained response to DBS, 26.6% were non responders, and 22.5% were partial responders, who might improve at some point but experience relapses during follow-up. A significant improvement in depressive symptoms and global functionality was observed in most studies, usually (although not always) in parallel with an improvement in obsessive symptoms. Most adverse effects of DBS were mild and transient and improved after adjusting stimulation parameters; however, some severe adverse events including intracranial hemorrhages and infections were also described. Hypomania was the most frequently reported psychiatric side effect. The relationship between DBS and suicide risk is still controversial and requires further study. Finally, to date, no clear clinical or biological predictors of response can be established, probably because of the differences between studies in terms of the neuroanatomical targets and stimulation protocols assessed.

CONCLUSION

The present review confirms that DBS is a promising therapy for patients with severe resistant OCD, providing both ST and LT evidence of efficacy.

Deep brain stimulation versus ablative surgery for treatment-refractory obsessive-compulsive disorder: A meta-analysis

OBJECTIVE

Ablative surgery (ABL) and deep brain stimulation (DBS) are last-resort treatment options for patients suffering from treatment-refractory obsessive-compulsive disorder (OCD). The aim of this study was to conduct an updated meta-analysis comparing the clinical outcomes of the ablative procedures capsulotomy and cingulotomy and deep brain stimulation.

METHODS

We conducted a PubMed search to identify all clinical trials on capsulotomy, cingulotomy, and DBS. Random effects meta-analyses were performed on 38 articles with a primary focus on efficacy in reducing OCD symptoms as measured by a reduction in the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score and the responder rate (≥35% reduction in Y-BOCS score).

RESULTS

With responder rates of 48% and 53% after 12-16 months and 56% and 57% at last follow-up for ABL and DBS, respectively, and large effect sizes in the reduction in Y-BOCS scores, both surgical modalities show effectiveness in treating refractory OCD. Meta-regression did not show a statistically significant difference between ABL and DBS regarding these outcomes. Regarding adverse events, a statistically significant higher rate of impulsivity is reported in studies on DBS.

CONCLUSION

This meta-analysis shows equal efficacy of ABL and DBS in the treatment of refractory OCD. For now, the choice of intervention should, therefore, rely on factors such as risk of developing impulsivity, patient preferences, and experiences of psychiatrist and neurosurgeon. Future research should provide more insight regarding differences between ABL and DBS and response prediction following direct comparisons between the surgical modalities, to enable personalized and legitimate choices between ABL and DBS.

Neuroimaging evaluation of deep brain stimulation in the treatment of representative neurodegenerative and neuropsychiatric disorders

Brain stimulation technology has become a viable modality of reversible interventions in the effective treatment of many neurological and psychiatric disorders. It is aimed to restore brain dysfunction by the targeted delivery of specific electronic signal within or outside the brain to modulate neural activity on local and circuit levels. Development of therapeutic approaches with brain stimulation goes in tandem with the use of neuroimaging methodology in every step of the way. Indeed, multimodality neuroimaging tools have played important roles in target identification, neurosurgical planning, placement of stimulators and post-operative confirmation. They have also been indispensable in pre-treatment screen to identify potential responders and in post-treatment to assess the modulation of brain circuitry in relation to clinical outcome measures. Studies in patients to date have elucidated novel neurobiological mechanisms underlying the neuropathogenesis, action of stimulations, brain responses and therapeutic efficacy. In this article, we review some applications of deep brain stimulation for the treatment of several diseases in the field of neurology and psychiatry. We highlight how the synergistic combination of brain stimulation and neuroimaging technology is posed to accelerate the development of symptomatic therapies and bring revolutionary advances in the domain of bioelectronic medicine.

A multicenter, open-label, controlled trial on acceptance, convenience, and complications of rechargeable internal pulse generators for deep brain stimulation: the Multi Recharge Trial

OBJECTIVE

Rechargeable neurostimulators for deep brain stimulation have been available since 2008, promising longer battery life and fewer replacement surgeries compared to non-rechargeable systems. Long-term data on how recharging affects movement disorder patients are sparse. This is the first multicenter, patient-focused, industry-independent study on rechargeable neurostimulators.

METHODS

Four neurosurgical centers sent a questionnaire to all adult movement disorder patients with a rechargeable neurostimulator implanted at the time of the trial. The primary endpoint was the convenience of the recharging process rated on an ordinal scale from "very hard" (1) to "very easy" (5). Secondary endpoints were charge burden (time spent per week on recharging), user confidence, and complication rates. Endpoints were compared for several subgroups.

RESULTS

Datasets of 195 movement disorder patients (66.1% of sent questionnaires) with Parkinson's disease (PD), tremor, or dystonia were returned and included in the analysis. Patients had a mean age of 61.3 years and the device was implanted for a mean of 40.3 months. The overall convenience of recharging was rated as "easy" (4). The mean charge burden was 122 min/wk and showed a positive correlation with duration of therapy; 93.8% of users felt confident recharging the device. The rate of surgical revisions was 4.1%, and the infection rate was 2.1%. Failed recharges occurred in 8.7% of patients, and 3.6% of patients experienced an interruption of therapy because of a failed recharge. Convenience ratings by PD patients were significantly worse than ratings by dystonia patients. Caregivers recharged the device for the patient in 12.3% of cases. Patients who switched from a non-rechargeable to a rechargeable neurostimulator found recharging to be significantly less convenient at a higher charge burden than did patients whose primary implant was rechargeable. Age did not have a significant impact on any endpoint.

CONCLUSIONS

Overall, patients with movement disorders rated recharging as easy, with low complication rates and acceptable charge burden.

Deep Brain Stimulation for Obsessive-Compulsive Disorder: A Long Term Naturalistic Follow Up Study in a Single Institution

INTRODUCTION

Deep brain stimulation (DBS) is a proven, effective tool in the treatment of movement disorders. Expansion of indications for DBS into the realm of neuropsychiatric disorders, especially obsessive-compulsive disorder (OCD), has gained fervent interest, although data on appropriate clinical utilization remains limited.

METHODS

A retrospective, naturalistic study followed nine severely affected OCD patients (average YBOCs score before implantation 34.2 ± 2.5) treated with DBS of ventral capsule/ventral striatum, with average follow up of 54.8 months.

RESULTS

With chronic stimulation (years), a majority of the patients achieved significant benefits in obsessive-compulsive and depressive symptoms. Six patients experienced periods of OCD remission following implantation. Four of the six responders required more than 12 months to achieve response. Relief of major depressive symptoms occurred in four out of six patients with documented co-morbid depression. Settings required to achieve efficacy were higher than those typically utilized for movement disorders, necessitating increased impulse generator (IPG) battery demand. We found patients benefited from conversion to a rechargeable IPG to prevent serial operations for IPG replacement. For patients with rechargeable IPGs, the repetitive habit of recharging did not appear to aggravate or trigger new obsessive-compulsive behaviors or anxiety symptoms.

CONCLUSIONS

Our study supports and builds upon other research suggesting that DBS for OCD in a real-world setting can be implemented successfully and provide long-term benefit for severely affected OCD patients. Optimal patient selection and DBS programming criteria are discussed. The use of rechargeable IPGs appears to be both cost effective and well-tolerated in this population.

Reduced long-term cost and increased patient satisfaction with rechargeable implantable pulse generators for deep brain stimulation

OBJECTIVE

Deep brain stimulation (DBS) has revolutionized the treatment of neurological disease, but its therapeutic efficacy is limited by the lifetime of the implantable pulse generator (IPG) batteries. At the end of the battery life, IPG replacement surgery is required. New IPGs with rechargeable batteries (RC-IPGs) have recently been introduced and allow for decreased reoperation rates for IPG replacements. The authors aimed to examine the merits and limitations of these devices.

METHODS

The authors reviewed the medical records of patients who underwent DBS implantation at their institution. RC-IPGs were placed either during initial DBS implantation or during an IPG change. A cost analysis was performed that compared RC-IPGs with standard IPGs, and telephone patient surveys were conducted to assess patient satisfaction.

RESULTS

The authors identified 206 consecutive patients from 2011 to 2016 who underwent RC-IPG placement (mean age 61 years; 67 women, 33%). Parkinson's disease was the most common indication for DBS (n = 144, 70%), followed by essential tremor (n = 41, 20%), dystonia (n = 13, 6%), depression (n = 5, 2%), multiple sclerosis tremor (n = 2, 1%), and epilepsy (n = 1, 0.5%). DBS leads were typically placed bilaterally (n = 192, 93%) and targeted the subthalamic nucleus (n = 136, 66%), ventral intermediate nucleus of the thalamus (n = 43, 21%), internal globus pallidus (n = 21, 10%), ventral striatum (n = 5, 2%), or anterior nucleus of the thalamus (n = 1, 0.5%). RC-IPGs were inserted at initial DBS implantation in 123 patients (60%), while 83 patients (40%) were converted to RC-IPGs during an IPG replacement surgery. The authors found that RC-IPG implantation resulted in $60,900 of cost savings over the course of 9 years. Furthermore, patient satisfaction was high with RC-IPG implantation. Overall, 87.3% of patients who responded to the survey were satisfied with their device, and only 6.7% found the rechargeable component difficult to use. In patients who were switched from a standard IPG to RC-IPG, the majority who responded (70.3%) preferred the rechargeable IPG.

CONCLUSIONS

RC-IPGs can provide DBS patients with long-term therapeutic benefit while minimizing the need for battery replacement surgery. The authors have implanted rechargeable stimulators in 206 patients undergoing DBS surgery, and here they demonstrate the cost-effectiveness and high patient satisfaction associated with this procedure.

Clinical Efficacy of Bilateral Deep Brain Stimulation Does Not Change After Implantable Pulse Generator Replacement but the Impedances Do: A Prospective Study

BACKGROUND

Deep brain stimulation (DBS) is an approved therapy option for movement disorders such as Parkinson's disease (PD), essential Tremor (ET), and dystonia. While current research focuses on rechargeable implantable pulse generators (IPGs), little is known about changes of the motor functions after IPG replacement and the consequences of additionally implanted hardware.

OBJECTIVE

To assess changes of the motor functions, the therapy impedances, and the total electric energy delivered (TEED) after elective IPG replacement.

METHODS

We prospectively acquired the data of 47 patients with PD, ET, and dystonia treated with bilateral DBS. Motor functions were rated prior to and after surgery using the revised Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS-III), the Fahn-Tolosa-Marin Tremor-Rating-Scale (FTM-TRS), and the Unified Dystonia Rating Scale (UDRS). Furthermore, the therapy impedances and TEED were assessed at the aforementioned times.

RESULTS

While preoperative motor scores were 48.32 ± 17.16 in PD, 39.71 ± 12.28 in ET, and 18.48 ± 16.30 in dystonia patients, postoperative scores were 47.84 ± 24.33, 32.86 ± 15.82, and 15.02 ± 15.17, respectively. Only in dystonia patients, motor scores significantly differed. Perioperative therapy impedance changes were 142.66 ± 105.35 Ω (Kinetra® to Activa® PC), -68.75 ± 43.05 Ω (Activa® PC to Activa® PC), and - 51.38 ± 38.75 Ω (Activa® PC to Activa® RC). Perioperative TEED changes were - 37.15 ± 38.87 μJ, 2.03 ± 35.91 μJ, and 12.39 ± 6.31 μJ in that first, second, and third group, respectively. Both the therapy impedances and TEED significantly differed between groups.

CONCLUSION

Although there were no statistically significant changes in the motor functions of all patients after elective IPG replacement, the therapy impedances were significantly higher and TEED was significantly lower after IPG replacement with concurrent Pocket Adapter implantation.

Comparative effectiveness of neuroablation and deep brain stimulation for treatment-resistant obsessive-compulsive disorder: a meta-analytic study

BACKGROUND

The safety and efficacy of neuroablation (ABL) and deep brain stimulation (DBS) for treatment refractory obsessive-compulsive disorder (OCD) has not been examined. This study sought to generate a definitive comparative effectiveness model of these therapies.

METHODS

A EMBASE/PubMed search of English-language, peer-reviewed articles reporting ABL and DBS for OCD was performed in January 2018. Change in quality of life (QOL) was quantified based on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the impact of complications on QOL was assessed. Mean response of Y-BOCS was determined using random-effects, inverse-variance weighted meta-analysis of observational data.

FINDINGS

Across 56 studies, totalling 681 cases (367 ABL; 314 DBS), ABL exhibited greater overall utility than DBS. Pooled ability to reduce Y-BOCS scores was 50.4% (±22.7%) for ABL and was 40.9% (±13.7%) for DBS. Meta-regression revealed no significant change in per cent improvement in Y-BOCS scores over the length of follow-up for either ABL or DBS. Adverse events occurred in 43.6% (±4.2%) of ABL cases and 64.6% (±4.1%) of DBS cases (p<0.001). Complications reduced ABL utility by 72.6% (±4.0%) and DBS utility by 71.7% (±4.3%). ABL utility (0.189±0.03) was superior to DBS (0.167±0.04) (p<0.001).

INTERPRETATION

Overall, ABL utility was greater than DBS, with ABL showing a greater per cent improvement in Y-BOCS than DBS. These findings help guide success thresholds in future clinical trials for treatment refractory OCD.