Economic Analysis of Deep Brain Stimulation in Parkinson Disease: Systematic Review of the Literature

How Long Does Deep Brain Stimulation Give Patients Benefit?

INTRODUCTION

One of the most common questions patients ask when they are contemplating deep brain stimulation (DBS) is how long it will last. To guide physicians in answering this query, we performed a scoping review to assess the current state of the literature and to identify the gaps that need to be addressed.

MATERIALS AND METHODS

The authors performed a MEDLINE search inclusive of articles from January 1987 (advent of DBS literature) to June 2023 including human and modeling studies written in English. For longevity of therapy data, only studies with a mean follow-up of ≥three years were included. Using the Rayyan platform, two reviewers (JP and RM) performed a title screen. Of the 734 articles, 205 were selected by title screen and 109 from abstract review. Ultimately, a total of 122 articles were reviewed. The research questions we explored were 1) how long can the different components of the DBS system maintain functionality? and 2) how long can DBS remain efficacious in treating Parkinson's disease (PD), essential tremor (ET), dystonia, and other disorders?

RESULTS

We showed that patients with PD, ET, and dystonia maintain a considerable long-term benefit in motor scores seven to ten years after implant, although the percentage improvement decreases over time. Stimulation off scores in PD and ET show worsening, consistent with disease progression. Battery life varies by the disease treated and the programming settings used. There remains a paucity of literature after ten years, and the impact of new device technology has not been classified to date.

CONCLUSION

We reviewed existing data on DBS longevity. Overall, outcomes data after ten years of therapy are substantially limited in the current literature. We recommend that physicians who have data for patients with DBS exceeding this duration publish their results.

Cost Effectiveness of Deep Brain Stimulation for Parkinson's Disease: A Systematic Review

BACKGROUND AND OBJECTIVE

Deep brain stimulation (DBS) is an established treatment for Parkinson's disease (PD) in patients with advanced motor symptoms with an inadequate response to pharmacotherapies. Despite its effectiveness, the cost effectiveness of DBS remains a subject of debate. This systematic review aims to update and synthesize evidence on the cost effectiveness of DBS for PD.

METHODS

To identify full economic evaluations that compared the cost effectiveness of DBS with other best medical treatments, a comprehensive search was conducted of the PubMed, Embase, Scopus, and Tufts Cost-Effective Analysis registry databases. The selected papers were systematically reviewed, and the results were summarized. For the quality appraisal, we used the modified economic evaluations bias checklist. The review protocol was a priori registered with PROSPERO, CRD42022345508.

RESULTS

Sixteen identified cost-utility analyses that reported 19 comparisons on the use of DBS for PD were systematically reviewed. The studies were primarily conducted in high-income countries and employed Markov models. The costs considered were direct costs: surgical expenses, calibration, pulse generator replacement, and annual drug expenses. The majority of studies used country-specific thresholds. Fourteen comparisons from 12 studies reported on the cost effectiveness of DBS compared to best medical treatments. Eleven comparisons reported DBS as cost effective based on incremental cost-utility ratio results.

CONCLUSIONS

The cost effectiveness of DBS for PD varies by time horizon, costs considered, threshold utilized, and stage of PD progression. Standardizing approaches and comparing DBS with other treatments are needed for future research on effective PD management.

Economic Evaluations Comparing Deep Brain Stimulation to Best Medical Therapy for Movement Disorders: A Meta-Analysis

BACKGROUND

Movement disorders (Parkinson's disease, essential tremor, primary dystonia) are a debilitating group of conditions that are progressive in nature. The mainstay of treatment is best medical therapy; however, a number of surgical therapies are available, including deep brain stimulation. Economic evaluations are an important aspect of evidence to inform decision makers regarding funding allocated to these therapies.

OBJECTIVE

This systematic review and meta-analysis evaluated the cost effectiveness of including deep brain stimulation compared with best medical therapy for movement disorder indications in the adult population.

METHODS

Ovid Medical Literature Analysis and Retrieval System Online, Embase, and Cochrane Central Register of Controlled Trials were queried. Only economic evaluations reporting incremental cost-effectiveness ratios for including deep brain stimulation versus best medical therapy for movement disorders were included. Studies were reviewed in duplicate for inclusion and data abstraction. Data were harmonized using the Consumer Price Index and Purchasing Power Parity to standardize values to 2022 US dollars. For inclusion in meta-analyses, studies were required to have sufficient data available to calculate an estimate of the incremental net benefit. Meta-analyses of pooled incremental net benefit based on the time horizon were performed. The study was registered at PROSPERO (CRD42022335436).

RESULTS

There were 2190 studies reviewed, with 14 economic evaluations included following a title/abstract and full-text review. Only studies considering Parkinson's disease were available for the meta-analysis. Quality of the identified studies was low, with moderate transferability to the American Healthcare System, and certainty of evidence was low. However, studies with a longer time horizon (15 years to lifetime) were found to have significant positive incremental net benefit (indicating cost effectiveness) for including deep brain stimulation with a mean difference of US$40,504.81 (95% confidence interval 2422.42-78,587.19).

CONCLUSIONS

Deep brain stimulation was cost effective for Parkinson's disease when considered over the course of the patient's remaining life after implantation.

TRIAL REGISTRATION

Clinical Trial Registration: PROSPERO (CRD42022335436).

[Problems in organizing neurosurgical care for patients with Parkinson's disease in the Russian Federation]

BACKGROUND

Currently, there are some problems in the Russian Federation complicating development of neurosurgical care for patients with Parkinson's disease (PD).

MATERIAL AND METHODS

In 2022, neurologists - movement disorders specialists were surveyed to analyze situation with PD pharmacological treatment and referral of patients for surgical treatment in Russian constituent entities. Data on neurosurgical treatment of PD were obtained by collecting information on the surgical activity of medical institutions in the Russian Federation. Most hospitals involved in PD treatment took part in this study.

RESULTS

The state of neurosurgical care for patients with PD is analyzed and possible ways to improve the quality of treatment are discussed.

CONCLUSION

Over the past 20 years, a system of neurosurgical care for patients with PD has been formed in 14 centers in the Russian Federation (2022). Obstacles to its further development can be divided into 3 categories: problems of patient selection and routing, complexity of organization and financing surgeries, and imperfect postoperative patient management. Ways to overcome these obstacles imply expanding the network of centers for extrapyramidal diseases, development of domestic neurostimulation systems, improving the distribution of quotas taking into account the capabilities of hospitals, specialized training of neurologists for extrapyramidal centers and neurosurgeons for deep brain stimulation centers, adequate financing and systematization of postoperative management of patients with PD.

Modelling the Cost Effectiveness of Treatments for Parkinson's Disease: An Updated Methodological Review

OBJECTIVE

This article systematically reviewed the methodological quality of modelling approaches for economic evaluations of the treatment of motor symptoms in Parkinson's disease in studies published after 2010.

METHODS

A systematic literature search was undertaken using PubMed, EconLit, the Cochrane Database of Systematic Reviews, National Health Service Economic Evaluation Database and Health Technology Assessment databases of the UK National Health Service Centre for Review and Dissemination (March 2010 to July 2022). Quality was assessed using a checklist from the German Scientific Working Group.

RESULTS

A total of 20 studies were evaluated, with the majority based on Markov models (n = 18). Studies assessed the cost effectiveness of medical (n = 12) or surgical (n = 8) treatment, and included costs from a payer or healthcare provider's perspective (n = 17). Furthermore, all studies included quality-adjusted life-years as an effect measure. In the quality assessment of the literature, a mean score of 42.1 points (out of 56 points) on the checklist of the German Scientific Working Group was achieved. Seventeen studies concluded the intervention under study was (likely) cost effective. No intervention was classified as cost ineffective.

CONCLUSIONS

The quality of economic evaluation models in Parkinson's disease has improved in terms of calculating cost and transition parameters, as well as carrying out probabilistic sensitivity analyses, compared with the published literature of previous systematic reviews up to 2010. However, there is still potential for further development in terms of the integration of non-motor complications and treatment changes, the transparent presentation of parameter estimates, as well as conducting sensitivity analyses and validations to support the interpretation of results.

Surgical Outcomes in Rare Movement Disorders: A Report of Seventeen Patients from India and Review of Literature

Background:

Rare movement disorders (RMDs) throw remarkable challenges to their appropriate management particularly when they are medically refractory. We studied the outcome of functional neurosurgery among patients with RMDs.

Methods:

Retrospective chart-review from 2006 to 2021 of patients with RMDs who underwent either Deep brain Stimulation (DBS) or lesional surgeries in the department of Neurology and Neurosurgery at a tertiary care centre.

Results:

Seventeen patients were included. Generalized dystonia (11 patients, 64.7%) and tremor (5 patients, 29.4%) were the most common indication for surgery whereas, Wilson’s disease (8 patients, 47.1%) and Neurodegeneration with brain iron accumulation (5 patients, 29.4%) were the most common aetiology. Sixteen patients (94.1%) had objective clinical improvement. Significant improvement was noted in the dystonia motor scores both at 6-months and 12-months follow-up (n = 11, p-value of <0.01 and 0.01 respectively). Comparison between DBS and lesional surgery showed no significant difference in the outcomes (p = 0.95 at 6-months and p = 0.53 at 12-months), with slight worsening of scores in the DBS arm at 12-months. Among five patients of refractory tremor with Wilson’s disease, there was remarkable improvement in the tremor scores by 85.0 ± 7.8% at the last follow-up. Speech impairment was the main complication observed with most of the other adverse events either transient or reversible.

Discussion:

Surgical options should be contemplated among patients with disabling medically refractory RMDs irrespective of the aetiology. Key to success lies in appropriate patient selection. In situations when DBS is not feasible, lesional surgeries can offer an excellent alternative with comparable efficacy and safety.

Current Therapies in Clinical Trials of Parkinson's Disease: A 2021 Update

Parkinson's disease (PD) is a progressive neurodegenerative disorder that currently has no cure, but treatments are available to improve PD symptoms and maintain quality of life. In 2020, about 10 million people worldwide were living with PD. In 1970, the United States Food and Drug Administration approved the drug levodopa as a dopamine replacement to manage PD motor symptoms; levodopa-carbidopa combination became commercialized in 1975. After over 50 years of use, levodopa is still the gold standard for PD treatment. Unfortunately, levodopa therapy-induced dyskinesia and OFF symptoms remain unresolved. Therefore, we urgently need to analyze each current clinical trial's status and therapeutic strategy to discover new therapeutic approaches for PD treatment. We surveyed 293 registered clinical trials on ClinicalTrials.gov from 2008 to 16 June 2021. After excluded levodopa/carbidopa derivative add-on therapies, we identified 47 trials as PD treatment drugs or therapies. Among them, 19 trials are in phase I (41%), 25 trials are in phase II (53%), and 3 trials are in phase III (6%). The three phase-III trials use embryonic dopamine cell implant, 5-HT_1A receptor agonist (sarizotan), and adenosine A_2A receptor antagonist (caffeine). The therapeutic strategy of each trial shows 29, 5, 1, 5, 5, and 2 trials use small molecules, monoclonal antibodies, plasma therapy, cell therapy, gene therapy, and herbal extract, respectively. Additionally, we discuss the most potent drug or therapy among these trials. By systematically updating the current trial status and analyzing the therapeutic strategies, we hope this review can provide new ideas and insights for PD therapy development.

Health, social, and economic consequences of rapid eye movement sleep behavior disorder: a controlled national study evaluating societal effects

STUDY OBJECTIVES

Parkinson's disease (PD) causes significant socioeconomic burdens. One of the strongest predictors of PD is rapid eye movement (REM) sleep behavior disorder (RBD; when there is no known other cause of RBD, referred to as idiopathic RBD [iRBD]), but there is no information about its factual welfare burden. We estimated the direct and indirect total costs of iRBD in a national sample of patients, based on a national register-based cohort study with matched controls.

METHODS

Using records from the Danish National Patient Registry, patient's diagnosis with RBD from 2006 to 2016 were identified. We excluded patients with a prior diagnosis of narcolepsy, PD, and other neurodegenerative diseases. We identified and compared randomly chosen controls matched for age, gender, geographic area, and civil status. Direct costs included frequencies of primary and secondary sector contacts and procedures, and medication. Indirect costs included the effect on labor supply. Social-transfer payments were included to illustrate the effect on national accounts.

RESULTS

A total of 246 iRBD patients and 982 matched controls were registered. iRBD patients had significantly higher rates of health-related contacts and of medication use, and higher socioeconomic costs than controls. The total additional direct net healthcare costs after the diagnosis (general practitioner services, hospital services, and medication) and indirect costs (loss of labor market income) was €13,088 for patients compared with controls. Patients already exhibited a negative social- and health-related status several years before the first diagnosis.

CONCLUSIONS

Diagnoses of iRBD have major socioeconomic consequences for patients, their partners, and society.

Radiofrequency ablation of the centromedian thalamic nucleus in the treatment of drug-resistant epilepsy

OBJECTIVE

To determine the usefulness and efficacy of radiofrequency ablations (RFA) of the Centromedian thalamic nucleus (CMN) to control primarily generalized or multifocal seizures in refractory epilepsy.

METHODS

Six patients with clinical diagnosis of multifocal or primarily generalized drug-resistant epilepsy were included. Bilateral RFA of the CMN was performed through a monopolar 1.8 mm. tip electrode with a temperature of 80 °C during 90 seconds. Patients were followed in every 3 months visit for 20 to 36 months and kept a monthly seizure count calendar. We also compared maximal paroxysmal electroencephalogram (EEG) activity and neuropsychological evaluation pre and 6 months postoperatively.

RESULTS

A significant reduction in the number of generalized seizures was observed in all subjects in the range of 79-98%, starting the first post-operative month. Although focal aware seizures remained unchanged throughout follow-up, there was an important reduction on paroxysmal activity between the pre and postoperative EEG. No major changes on cognitive status were detected. There was post-operative dysphagia and odynophagia lasting one week and there was no mortality in this group of patients.

CONCLUSION

Preliminary results of CMN RFA suggest safety and a trend toward reduction of some seizure types, it may reduce the seizure frequency like other palliative procedures since the first post-operative month, but a larger, controlled study would be needed to establish the value of this therapy.

Direct Cost of Parkinson's Disease: A Real-World Data Study of Second-Line Therapies

Parkinson's disease is one of the main reasons for neurological consultation in Spain. Due to the nature of the disease, it impacts patients, families, and caregivers. Parkinson's disease is a degenerative disease with no cure, although second-line therapies have recently improved the quality of life of patients in advanced stages. The aim of this study was to analyse the costs of the following therapies: deep brain stimulation (DBS), continuous duodenal levodopa/carbidopa infusion (CDLCI), and continuous subcutaneous apomorphine infusion (CSAI). The methodology used was based on real-world data obtained from an integrated healthcare organization in the Basque Country from 2016 to 2018. This bottom-up retrospective approach only took into account the healthcare perspective. The results revealed the annual cost over 3 years and the projected cost for an additional 2 years. The total costs for 5 years of treatment were as follows: €53,217 for DBS, €208,163 for CDLCI, and €170,591 for CSAI. These costs are in line with those found in the available literature on the subject. Additionally, the analysis provided details of the different costs incurred during intervention with the therapies and compared the costs to those reported in other studies.

Creation of a gene expression classifier for predicting Parkinson's disease rate of progression

Parkinson's disease (PD) etiology is heterogeneous, genetic, and multi-factorial, resulting in a varied disease from a mild slow progression to a more severe rapid progression. Prognostic information on the nature of the patient's disease at diagnosis aids the physician in counseling patients on treatment options and life planning. In a cohort of PD patients from the PPMI study, the relative gene expression levels of SKP1A, UBE2K, ALDH1A1, PSMC4, HSPA8 and LAMB2 were measured in baseline blood samples by real-time quantitative PCR. At baseline PD patients were up to 2 years from diagnosis, H&Y scale ≤ 2 and PD treatment naïve. PD-Prediction algorithm comprised of ALDH1A1, LAMB2, UBE2K, SKP1A and age was created by logistic regression for predicting progression to ≤ 70% Modified Schwab and England Activities of Daily Living (S&E-ADL). In relation to patients negative for PD-Prediction (n = 180), patients positive (n = 30) for Cutoff-1 (at 82% specificity, 80.0% sensitivity) had positive hazard ratio (HR+) of 10.6 (95% CI, 2.2-50.1), and positive (n = 23) for Cutoff-2 (at 93% specificity, 47% sensitivity) had HR+ of 17.1 (95% CI, 3.2-89.9) to progress to ≤ 70% S&E-ADL within 3 years (P value < 0.0001). Likewise, patients positive for PD-Prediction Cutoff-1 (n = 49) had HR+ 4.3 (95% CI, 1.6-11.6) for faster time to H&Y 3 in relation to patients negative (n = 170) for PD-Prediction (P value = 0.0002). Our findings show an algorithm that seems to predict fast PD progression and may potentially be used as a tool to assist the physician in choosing an optimal treatment plan, improving the patient's quality of life and overall health outcome.

Pulse generator battery life in deep brain stimulation: out with the old… in with the less durable?

BACKGROUND

Battery life of the most commonly used implantable pulse generators in deep brain stimulation is limited. Device replacement is costly and may expose patients to additional risks. Driven by the observation that in our experience newer generation devices seemed to need earlier replacement than the older generation, we aimed to retrospectively analyze the battery life of two generations of non-rechargeable devices, manufactured by a single company (Medtronic, USA).

METHODS

Battery life of 281 devices in 165 patients was taken into account for data analysis. This represented 243 older generation devices (Kinetra and Soletra) and 38 newer generation devices (Activa).

RESULTS

The battery life of older generation stimulators was 2-fold longer than the newer generation.

CONCLUSIONS

Newer devices are more versatile than the older generation. Their battery life is however significantly shorter. Development of next-generation devices needs to address this issue in order to limit health risks and reduce financial costs.

The Use of Neuromodulation for Symptom Management

Pain and other symptoms of autonomic dysregulation such as hypertension, dyspnoea and bladder instability can lead to intractable suffering. Incorporation of neuromodulation into symptom management, including palliative care treatment protocols, is becoming a viable option scientifically, ethically, and economically in order to relieve suffering. It provides further opportunity for symptom control that cannot otherwise be provided by pharmacology and other conventional methods.

Efficacy and safety of extended-release amantadine in levodopa-induced dyskinesias: a meta-analysis

Aim: To determine the effectiveness and safety of extended-release amantadine (ADS-5102) for levodopa-induced dyskinesias (LID) in patients with Parkinson disease (PD) by conducting a meta-analysis of relevant trials. Methods: The electronic databases were searched on or before March 1, 2019 for relevant trials. Only randomized, double-blind, parallel-group, placebo-controlled trials using ADS-5102 for LID in PD were included. Results: The ADS-5102 showed a reduction in the dyskinesia scores (mean difference: -9.56: CI: -10.05 to -9.07; p < 0.00001) and in the on time without troublesome dyskinesia (mean difference 2.50: CI 2.38 to 2.63; p < 0.00001). The adverse events identified in ADS-5102 were visual hallucinations, constipation, dry mouth and fall. Conclusion: ADS-5102 can be used as an adjunct therapy for LID.

Cost-Effectiveness of Deep Brain Stimulation With Movement Disorders: A Systematic Review

BACKGROUND

Movement disorders (MDs) are increasingly being managed with deep brain stimulation (DBS). High-quality economic evaluations (EEs) are necessary to evaluate the cost-effectiveness of DBS. We conducted a systematic review of published EEs of the treatment of MDs with DBS. The review compares and contrasts the reported incremental cost-effectiveness ratios (ICERs) and methodology employed by trial-based evaluations (TBEs) and model-based evaluations (MBEs).

METHODS

MeSH and search terms relevant to "MDs," "DBS," and "EEs" were used to search biomedical and economics databases. Studies that used a comparative design to evaluate DBS, including before-after studies, were included. Quality and reporting assessments were conducted independently by 2 authors. Seventeen studies that targeted Parkinson's disease (PD), dystonia, and essential tremor (ET), met our selection criteria.

RESULTS

Mean scores for methodological and reporting quality were 73% and 76%, respectively. The ICERs for DBS compared with best medical therapy to treat PD patients obtained from MBEs had a lower mean and range compared with those obtained from TBEs ($55,461-$735,192 per quality-adjusted life-year [QALY] vs. $9,301-$65,111 per QALY). Pre-post ICER for DBS to treat dystonia was $64,742 per QALY. DBS was not cost-effective in treating ET compared with focused-ultrasound surgery. Cost-effectiveness outcomes were sensitive to assumptions in health utilities, surgical costs, battery life-span, model time horizons, and the discount rate.

CONCLUSIONS

The infrequent use of randomized, controlled trials to evaluate DBS efficacy, the paucity of data reporting the long-term effectiveness and/or utility of DBS, and the uncertainty surrounding cost data limit our ability to report cost-effectiveness summaries that are robust.

Economic Evaluation of Interventions in Parkinson's Disease: A Systematic Literature Review

BACKGROUND

Parkinson's disease (PD) management comprises of drug treatments, surgery, and physical activity/occupational therapies to relieve PD's symptoms. The aim of this study is twofold; first, to appraise recent economic evaluation studies on PD management in order to update the existing knowledge; and second, to facilitate decision making on PD management by assessing the cost-effectiveness of all types of PD interventions.

METHODS

A systematic search for studies published between 2010 and 2018 was conducted. The inclusion and exclusion of the articles were based on criteria relevant to population, intervention, comparison, outcomes, and study design (PICO). The reporting quality of the articles was assessed according to Consolidated Health Economic Evaluation Reporting Standards.

RESULTS

Twenty-eight articles were included, 10 of which were evaluations of drug treatments, 10 deep brain stimulation (DBS), and eight physical/occupational therapies. Among early-stage treatments, Ti Ji dominated all physical activity interventions; however, its cost-effectiveness should be further explored in relation to its duration, intensity, and frequency. Multidisciplinary interventions of joint medical and nonmedical therapies provided slightly better health outcomes for the same costs. In advanced PD patients, adjunct drug treatments could become more cost-effective if introduced during early PD and, although DBS was more cost-effective than adjunct drug therapies, the results were time-bound.

CONCLUSIONS

Conditionally, certain PD interventions are cost-effective. However, PD progression differs in each patient; thus, the cost-effectiveness of individually tailored combinations of interventions that could provide more time in less severe disease states and improve patients' and caregivers' quality of life, should be further explored.

Deep brain stimulation for dystonia

BACKGROUND

Dystonia is a painful and disabling disorder, characterised by painful, involuntary posturing of the affected body region(s). Deep brain stimulation is an intervention typically reserved for severe and drug-refractory cases, although uncertainty exists regarding its efficacy, safety, and tolerability.

OBJECTIVES

To compare the efficacy, safety, and tolerability of deep brain stimulation (DBS) versus placebo, sham intervention, or best medical care, including botulinum toxin and resective or lesional surgery, in adults with dystonia.

SEARCH METHODS

We identified studies by searching the CENTRAL, MEDLINE, Embase, three other databases, four clinical trial registries, four grey literature databases, and reference lists of included articles. We ran the last search of all elements of the search strategy, with no language restrictions, on 29 May 2018.

SELECTION CRITERIA

Double-blind, parallel, randomised, controlled trials (RCTs) comparing DBS with sham stimulation, best medical care, or placebo in adults with dystonia.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed records, selected included studies, extracted data onto a standardised (or prespecified) data extraction form, and evaluated the risk of bias. We resolved disagreements by consensus or by consulting a third review author. We conducted meta-analyses using a random-effects model, to estimate pooled effects and corresponding 95% confidence intervals (95% CI). We assessed the quality of the evidence with GRADE methods. The primary efficacy outcome was symptom improvement on any validated symptomatic rating scale, and the primary safety outcome was adverse events.

MAIN RESULTS

We included two RCTs, enrolling a total of 102 participants. Both trials evaluated the effect of DBS on the internal globus pallidus nucleus, and assessed outcomes after three and six months of stimulation. One of the studies included participants with generalised and segmental dystonia; the other included participants with focal (cervical) dystonia. We assessed both studies at high risk for performance and for-profit bias. One study was retrospectively registered with a clinical trial register, we judged the second at high risk of detection bias.Low-quality evidence suggests that DBS of the internal globus pallidus nucleus may improve overall cervical dystonia-related symptoms (mean difference (MD) 9.8 units, 95% CI 3.52 to 16.08 units; 1 RCT, 59 participants), cervical dystonia-related functional capacity (MD 3.8 units, 95% CI 1.41 to 6.19; 1 RCT, 61 participants), and mood at three months (MD 3.1 units, 95% CI 0.73 to 5.47; 1 RCT, 61 participants).Low-quality evidence suggests that In people with cervical dystonia, DBS may slightly improve the overall clinical status (MD 2.3 units, 95% CI 1.15 to 3.45; 1 RCT, 61 participants). We are uncertain whether DBS improves quality of life in cervical dystonia (MD 3 units, 95% CI -7.71 to 13.71; 1 RCT, 57 participants; very low-quality evidence), or emotional state (MD 2.4 units, 95% CI -6.2 to 11.00; 1 RCT, 56 participants; very low-quality evidence).Low-quality evidence suggests that DBS of the internal globus pallidus nucleus may improve generalised or segmental dystonia-related symptoms (MD 14.4 units, 95% CI 8.0 to 20.8; 1 RCT, 40 participants), overall clinical status (MD 3.5 units, 95% CI 2.33 to 4.67; 1 RCT, 37 participants), physical functioning-related quality of life (MD 6.3 units, 95% CI 1.06 to 11.54; 1 RCT, 33 participants), and overall dystonia-related functional capacity at three months (MD 3.1 units, 95% CI 1.71 to 4.48; 1 RCT, 39 participants). We are uncertain whether DBS improves physical functioning-related quality of life (MD 5.0 units, 95% CI -2.14 to 12.14, 1 RCT, 33 participants; very low-quality evidence), or mental health-related quality of life (MD -4.6 units, 95% CI -11.26 to 2.06; 1 RCT, 30 participants; very low-quality evidence) in generalised or segmental dystonia.We pooled outcomes related to safety and tolerability, since both trials used the same intervention and comparison. We found very low-quality evidence of inconclusive results for risk of adverse events (relative risk (RR) 1.58, 95% 0.98 to 2.54; 2 RCTs, 102 participants), and tolerability (RR 1.86, 95% CI 0.16 to 21.57; 2 RCTs,102 participants).

AUTHORS' CONCLUSIONS

DBS of the internal globus pallidus nucleus may reduce symptom severity and improve functional capacity in adults with cervical, segmental or generalised moderate to severe dystonia (low-quality evidence), and may improve quality of life in adults with generalised or segmental dystonia (low-quality evidence). We are uncertain whether the procedure improves quality of life in cervical dystonia (very low-quality evidence). We are also uncertain about the safety and tolerability of the procedure in adults with either cervical and generalised, or segmental dystonia (very-low quality evidence).We could draw no conclusions for other populations with dystonia (i.e. children and adolescents, and adults with other types of dystonia), or for other DBS protocols (i.e. other target nuclei or stimulation paradigms). Further research is needed to establish the long-term efficacy and safety of DBS of the internal globus pallidus nucleus.

Technical Note: Preemptive Surgical Revision of Impending Deep Brain Stimulation Hardware Erosion

BACKGROUND

While deep brain stimulation (DBS) is a relatively safe procedure, skin erosion is a commonly reported hardware complication that can threaten the DBS system. Patients with Parkinson disease are especially at risk for this complication due to their autonomic dysregulation and impaired nutrition. Early detection of impending skin erosion allows for intervention that may prevent hardware destruction. Here we report a novel technique to address this complication preemptively. We describe the use of an acellular dermal matrix to prevent skin erosion in 20 patients with Parkinson disease who were treated with DBS and showed signs of impending skin erosion.

METHODS

Twenty patients with signs of impending hardware erosion were identified. An acellular dermal matrix was surgically placed under the at-risk skin overlying the DBS lead.

RESULTS

None of the 20 patients treated with this technique went on to require further revision surgery or removal of hardware.

CONCLUSIONS

Surgical placement of acellular dermal matrix in patients identified as having impending hardware erosions is a safe and cost-effective way to prevent hardware complications.

The cost-effectiveness of deep brain stimulation for patients with treatment-resistant obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is a chronic neuropsychiatric disorder with a 2% to 3% lifetime prevalence; in addition, 10% of OCD patients are resistant to conventional therapy. Deep brain stimulation (DBS) has been an effective treatment for treatment resistant OCD patients (TROCD). We aimed to determine the cost-effectiveness of DBS for TROCD.

METHODS

We used a Markov model to estimate the cost-effectiveness of DBS compared to conventional treatment for TROCD with a 10-year time horizon. Published data were used to estimate the rates of treatment response and complications. Costs were calculated from the perspective of the third-party payer. Data on quality of life were obtained from a literature review and a survey of OCD patients. We applied the model separately to Korea and the United Kingdom (UK) to enhance the validity.

RESULTS

Base-case analysis showed an incremental cost-effectiveness ratio of US$37,865 per quality-adjusted life-year in Korea and US$34,462 per quality-adjusted life-year in the UK. According to the World Health Organization's criteria, DBS for TROCD was "cost-effective" in Korea (<3x GDP per capita) and "highly cost-effective" in the UK (<GDP per capita). One-way sensitivity analysis showed consistent cost-effectiveness results for most variables with the exception of short-term duration of treatment effect (<4 years in Korea; <3 years in the UK).

CONCLUSION

The results showed that DBS is a cost-effective treatment for TROCD in both the countries. Our findings provide economic evidence on the applicability of DBS for patients, health care service providers, and payers.

Cost-effectiveness of deep brain stimulation versus treatment as usual for obsessive-compulsive disorder

BACKGROUND

Deep Brain Stimulation (DBS) is effective for obsessive-compulsive disorder (OCD), but requires expensive medical procedures. To date, no study has examined the cost-effectiveness of DBS for OCD.

OBJECTIVE

To perform the first economic evaluation of DBS for therapy refractory OCD.

METHODS

We conducted a 2-year prospective, open cost-effectiveness study, comparing DBS (n = 17) with treatment as usual (TAU) (n = 11), with cost per Quality-Adjusted-Life-Year (QALY) as outcome measure. Apart from the base-case, or primary analysis, we conducted two practice-based scenarios: (1) standard care scenario, without research and innovation costs, and (2) rechargeable scenario, in which we assume the use of a rechargeable battery. Base-case and both scenarios were extrapolated to four years to estimate long-term cost-effectiveness.

RESULTS

Compared to TAU, DBS provides an additional 0.26 QALY (SD = 0.16). Median cost per QALY gained is estimated at €141,446 for base-case, €115,916 for standard care and €65,394 for the rechargeable scenario. Extending the time-horizon to four years results in a median cost per QALY of €80,313 for base-case, €69,287 for standard care, and turned out to be cost-saving at €4678 per QALY for the rechargeable scenario. Assuming a willingness to pay threshold of €80,000/QALY, DBS, under base-case and standard care had 25% and 35% probability of being more cost-effective than TAU. With the rechargeable scenario and in all scenarios extrapolated to four years, the probability of cost-effectiveness was equal or higher than TAU.

CONCLUSIONS

This study indicates DBS for OCD is cost-effective in the long-term, especially when rechargeable batteries are taken into account.