Uncoupling of dopaminergic and subthalamic stimulation: Life-threatening DBS withdrawal syndrome

Akinetic crisis and withdrawal syndromes: guideline "Parkinson's disease" of the German Society of Neurology

The akinetic crisis is a well-known, rare, potentially life-threatening condition in Parkinson's disease with subacute worsening of akinesia, rigidity, fever, impaired consciousness, accompanying vegetative symptoms and transient dopa-resistance. The akinetic crisis was historically supposed to be a "withdrawal syndrome" in the sense of discontinuation of dopaminergic medication. Recently, other "withdrawal syndromes" as the specific "dopamine agonist withdrawal syndrome" or "deep brain stimulation withdrawal syndrome" have been described as emergency situations with specific subacute symptom constellations. All three conditions require immediate start of the adequate therapy to improve the prognosis. Here, the diagnostic criteria and treatment options of these three acute, severely disabling syndromes will be reported along the current guidelines of the German Parkinson Guideline Group.

Disentangling Bradykinesia and Rigidity in Parkinson's Disease: Evidence from Short- and Long-Term Subthalamic Nucleus Deep Brain Stimulation

OBJECTIVE

Bradykinesia and rigidity are considered closely related motor signs in Parkinson disease (PD), but recent neurophysiological findings suggest distinct pathophysiological mechanisms. This study aims to examine and compare longitudinal changes in bradykinesia and rigidity in PD patients treated with bilateral subthalamic nucleus deep brain stimulation (STN-DBS).

METHODS

In this retrospective cohort study, the clinical progression of appendicular and axial bradykinesia and rigidity was assessed up to 15 years after STN-DBS in the best treatment conditions (ON medication and ON stimulation). The severity of bradykinesia and rigidity was examined using ad hoc composite scores from specific subitems of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III). Short- and long-term predictors of bradykinesia and rigidity were analyzed through linear regression analysis, considering various preoperative demographic and clinical data, including disease duration and severity, phenotype, motor and cognitive scores (eg, frontal score), and medication.

RESULTS

A total of 301 patients were examined before and 1 year after surgery. Among them, 101 and 56 individuals were also evaluated at 10-year and 15-year follow-ups, respectively. Bradykinesia significantly worsened after surgery, especially in appendicular segments (p < 0.001). Conversely, rigidity showed sustained benefit, with unchanged clinical scores compared to preoperative assessment (p > 0.05). Preoperative motor disability (eg, composite scores from the UPDRS-III) predicted short- and long-term outcomes for both bradykinesia and rigidity (p < 0.01). Executive dysfunction was specifically linked to bradykinesia but not to rigidity (p < 0.05).

INTERPRETATION

Bradykinesia and rigidity show long-term divergent progression in PD following STN-DBS and are associated with independent clinical factors, supporting the hypothesis of partially distinct pathophysiology. ANN NEUROL 2024;96:234-246.

Neuroscience fundamentals relevant to neuromodulation: Neurobiology of deep brain stimulation in Parkinson's disease

Deep Brain Stimulation (DBS) has become a pivotal therapeutic approach for Parkinson's Disease (PD) and various neuropsychiatric conditions, impacting over 200,000 patients. Despite its widespread application, the intricate mechanisms behind DBS remain a subject of ongoing investigation. This article provides an overview of the current knowledge surrounding the local, circuit, and neurobiochemical effects of DBS, focusing on the subthalamic nucleus (STN) as a key target in PD management. The local effects of DBS, once thought to mimic a reversible lesion, now reveal a more nuanced interplay with myelinated axons, neurotransmitter release, and the surrounding microenvironment. Circuit effects illuminate the modulation of oscillatory activities within the basal ganglia and emphasize communication between the STN and the primary motor cortex. Neurobiochemical effects, encompassing changes in dopamine levels and epigenetic modifications, add further complexity to the DBS landscape. Finally, within the context of understanding the mechanisms of DBS in PD, the article highlights the controversial question of whether DBS exerts disease-modifying effects in PD. While preclinical evidence suggests neuroprotective potential, clinical trials such as EARLYSTIM face challenges in assessing long-term disease modification due to enrollment timing and methodology limitations. The discussion underscores the need for robust biomarkers and large-scale prospective trials to conclusively determine DBS's potential as a disease-modifying therapy in PD.

Parkinsonism-hyperpyrexia, a rare consequence of deep brain stimulator malfunction in advanced Parkinson's disease

Parkinsonism-hyperpyrexia syndrome (PHS) is a rare neurological emergency that shares clinical features with neuroleptic malignant syndrome. It is usually due to sudden deprivation of dopaminergic treatment, although there are cases related to failure of the deep brain stimulation system.

Anthropology of Deep Brain Stimulation; the 30th Anniversary of STN DBS in 2023

Background

The year 2023 marks the 30th anniversary of deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinson's disease (PD). This procedure prompted a universal interest in DBS for various brain disorders and resulted in a unique expansion of clinical and scientific collaboration between many disciplines, with impact on many aspects of society.

Objective

To study the anthropology of DBS, that is, its ethno-geographic origins, its evolution, its impact on clinicians and scientists, and its influence on society at large.

Material and Methods

The authors scrutinized the geo-ethnic origins of the pioneers of modern DBS, and they evaluated, based on the literature and on a long-term praxis, the development of DBS and its impact on clinicians, on healthcare, and on society.

Results

Scientists and clinicians from various geo-ethnic origins pioneered modern DBS, leading to worldwide spread of this procedure and to the establishment of large multidisciplinary teams in many centers. Neurologists became actively involved in surgery and took on new laborious tasks of programming ever more complicated DBS systems. Publications sky-rocketed and the global spread of DBS impacted positively on several aspects of society, including healthcare, awareness of neurological diseases, interdisciplinary relations, conferences, patient organizations, unemployment, industry, etc.

Conclusions

STN DBS has boosted the field of deep brain electrotherapy for many neurological and psychiatric illnesses, and DBS has generated a global benefit on many aspects of society, well beyond its clinical benefits on symptoms of diseases. With the ever-increasing indications for DBS, more positive global impact is expected.

Essential Tremor - Deep Brain Stimulation vs. Focused Ultrasound

INTRODUCTION

Essential Tremor (ET) is one of the most common tremor syndromes typically presented as action tremor, affecting mainly the upper limbs. In at least 30-50% of patients, tremor interferes with quality of life, does not respond to first-line therapies and/or intolerable adverse effects may occur. Therefore, surgery may be considered.

AREAS COVERED

In this review, the authors discuss and compare unilateral ventral intermedius nucleus deep brain stimulation (VIM DBS) and bilateral DBS with Magnetic Resonance-guided Focused Ultrasound (MRgFUS) thalamotomy, which comprises focused acoustic energy generating ablation under real-time MRI guidance. Discussion includes their impact on tremor reduction and their potential complications. Finally, the authors provide their expert opinion.

EXPERT OPINION

DBS is adjustable, potentially reversible and allows bilateral treatments; however, it is invasive requires hardware implantation, and has higher surgical risks. Instead, MRgFUS is less invasive, less expensive, and requires no hardware maintenance. Beyond these technical differences, the decision should also involve the patient, family, and caregivers.

Pros and Cons of Ablation for Functional Neurosurgery in the Neurostimulation Age

Should one recommend stereotactic ablation for Parkinson disease, tremor, dystonia, and obsessive compulsive disorder, in this era of DBS? The answer depends on several variables such as the symptoms to treat, the patient's preferences and expectations, the surgeons' competence and preference, the availability of financial means (by government health care, by private insurance), the geographical issues, and not least the current and dominating fashion at that particular time. Both ablation and stimulation can be either used alone or even combined (provided expertise in both of them) to treat various symptoms of movement and mind disorders.

Deep Brain Stimulation-Withdrawal Syndrome in Parkinson's Disease: Risk Factors and Pathophysiological Hypotheses of a Life-Threatening Emergency

BACKGROUND AND OBJECTIVES

Subthalamic nucleus deep brain stimulation (DBS) is the most common therapeutic surgical procedure for patients with Parkinson's disease with motor fluctuations, dyskinesia, or tremor. Routine follow-up of patients allows clinicians to anticipate replacement of the DBS battery reaching the end of its life. Patients who experience a sudden stop of the DBS battery experience a rapid worsening of symptoms unresponsive to high dose of levodopa, in a life-threatening phenomenon called "DBS-withdrawal syndrome." In the current context of the COVID-19 pandemic, in which many surgeries are being deprogrammed, it is of utmost importance to determine to what extent DBS battery replacement surgeries should be considered an emergency. In this study, we attempt to identify risk factors of DBS-withdrawal syndrome and provide new insights about pathophysiological hypotheses. We then elaborate on the optimal approach to avoid and manage such a situation.

MATERIALS AND METHODS

We conducted a systematic review of the literature on the subject and reported the cases of 20 patients (including five from our experience) with DBS-withdrawal syndrome, comparing them with 15 undisturbed patients (including three from our experience), all having undergone neurostimulation discontinuation.

RESULTS

A long disease duration at battery removal and many years of DBS therapy are the main potential identified risk factors (p < 0.005). In addition, a trend for older age at the event and higher Unified Parkinson's Disease Rating Scale motor score before initial DBS implantation (evaluated in OFF-drug condition) was found (p < 0.05). We discuss several hypotheses that might explain this phenomenon, including discontinued functioning of the thalamic-basal ganglia loop due to DBS-stimulation cessation in a context in which cortical-basal ganglia loop had lost its cortical input, and possible onset of a severe bradykinesia through the simultaneous occurrence of an alpha and high-beta synchronized state.

CONCLUSIONS

The patients' clinical condition may deteriorate rapidly, be unresponsive to high dose of levodopa, and become life-threatening. Hospitalization is suggested for clinical monitoring. In the context of the current COVID-19 pandemic, it is important to widely communicate the replacement of DBS batteries reaching the end of their life. More importantly, in cases in which the battery has stopped, there should be no delay in performing replacement as an emergent surgery.

Deep brain stimulation for Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative illness with both motor and nonmotor symptoms. Deep brain stimulation (DBS) is an established safe neurosurgical symptomatic therapy for eligible patients with advanced disease in whom medical treatment fails to provide adequate symptom control and good quality of life, or in whom dopaminergic medications induce severe side effects such as dyskinesias. DBS can be tailored to the patient's symptoms and targeted to various nodes along the basal ganglia-thalamus circuitry, which mediates the various symptoms of the illness; DBS in the thalamus is most efficient for tremors, and DBS in the pallidum most efficient for rigidity and dyskinesias, whereas DBS in the subthalamic nucleus (STN) can treat both tremors, akinesia, rigidity and dyskinesias, and allows for decrease in doses of medications even in patients with advanced stages of the disease, which makes it the preferred target for DBS. However, DBS in the STN assumes that the patient is not too old, with no cognitive decline or relevant depression, and does not exhibit severe and medically resistant axial symptoms such as balance and gait disturbances, and falls. Dysarthria is the most common side effect of DBS, regardless of the brain target. DBS has a long-lasting effect on appendicular symptoms, but with progression of disease, nondopaminergic axial features become less responsive to DBS. DBS for PD is highly specialised; to enable adequate selection and follow-up of patients, DBS requires dedicated multidisciplinary teams of movement disorder neurologists, functional neurosurgeons, specialised DBS nurses and neuropsychologists.

Parkinsonism-Hyperpyrexia Syndrome: A Case Series and Literature Review

Parkinsonism-hyperpyrexia syndrome (PHS) is a rare, potentially fatal neurological emergency, that is seen in Parkinson’s Disease (PD) patients and mimics neuroleptic malignant syndrome. The most common trigger for PHS is sudden withdrawal of anti-parkinsonian medications, specifically levodopa. However, it can also be due to Deep Brain Stimulation (DBS) device malfunction. In this work, we describe three cases of PHS; the first of which is related to DBS battery depletion, and the remaining two to dopaminergic withdrawal. Additionally, we will include the results of a literature review on PHS, its etiologies, presentation, and management.

Axial impairment and falls in Parkinson’s disease: 15 years of subthalamic deep brain stimulation

In this retrospective study, we longitudinally analyzed axial impairment and falls in people with Parkinson’s disease (PD) and subthalamic nucleus deep brain stimulation (STN-DBS). Axial scores and falling frequency were examined at baseline, and 1, 10, and 15 years after surgery. Preoperative demographic and clinical data, including PD duration and severity, phenotype, motor and cognitive scales, medications, and vascular changes on neuroimaging were examined as possible risk factors through Kaplan–Meier and Cox regression analyses. Of 302 individuals examined before and at 1 year after surgery, 102 and 57 were available also at 10 and 15 years of follow-up, respectively. Axial scores were similar at baseline and at 1 year but worsened at 10 and 15 years. The prevalence rate of frequent fallers progressively increased from baseline to 15 years. Preoperative axial scores, frontal dysfunction and age at PD onset were risk factors for axial impairment progression after surgery. Axial scores, akinetic/rigid phenotype, age at disease onset and disease duration at surgery predicted frequent falls. Overall, axial signs progressively worsened over the long-term period following STN-DBS, likely related to the progression of PD, especially in a subgroup of subjects with specific risk factors.

Evidence of Neuroplastic Changes after Transcranial Magnetic, Electric, and Deep Brain Stimulation

Electric and magnetic stimulation of the human brain can be used to excite or inhibit neurons. Numerous methods have been designed over the years for this purpose with various advantages and disadvantages that are the topic of this review. Deep brain stimulation (DBS) is the most direct and focal application of electric impulses to brain tissue. Electrodes are placed in the brain in order to modulate neural activity and to correct parameters of pathological oscillation in brain circuits such as their amplitude or frequency. Transcranial magnetic stimulation (TMS) is a non-invasive alternative with the stimulator generating a magnetic field in a coil over the scalp that induces an electric field in the brain which, in turn, interacts with ongoing brain activity. Depending upon stimulation parameters, excitation and inhibition can be achieved. Transcranial electric stimulation (tES) applies electric fields to the scalp that spread along the skull in order to reach the brain, thus, limiting current strength to avoid skin sensations and cranial muscle pain. Therefore, tES can only modulate brain activity and is considered subthreshold, i.e., it does not directly elicit neuronal action potentials. In this review, we collect hints for neuroplastic changes such as modulation of behavior, the electric activity of the brain, or the evolution of clinical signs and symptoms in response to stimulation. Possible mechanisms are discussed, and future paradigms are suggested.

How Does Deep Brain Stimulation Change the Course of Parkinson's Disease?

A robust body of evidence from randomized controlled trials has established the efficacy of deep brain stimulation (DBS) in reducing off time and dyskinesias in levodopa‐treated patients with Parkinson's disease (PD). These effects go along with improvements in on period motor function, activities of daily living, and quality of life. In addition, subthalamic DBS is effective in controlling drug‐refractory PD tremor. Here, we review the available data from long‐term observational and controlled follow‐up studies in DBS‐treated patients to re‐examine the persistence of motor and quality of life benefits and evaluate the effects on disease progression, major disability milestones, and survival. Although there is consistent evidence from observational follow‐up studies in DBS‐treated patients over 5–10 years and beyond showing sustained improvement of motor control, the long‐term impact of DBS on overall progression of disability in PD is less clear. Whether DBS reduces or delays the development of later motor and non‐motor disability milestones in comparison to best medical management strategies is difficult to answer by uncontrolled observational follow‐up, but there are signals from controlled long‐term observational studies suggesting that subthalamic DBS may delay some of the late‐stage disability milestones including psychosis, falls, and institutionalization, and also slightly prolongs survival compared with matched medically managed patients. These observations could be attributable to the sustained improvements in motor function and reduction in medication‐induced side effects, whereas there is no clinical evidence of direct effects of DBS on the underlying disease progression. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Treatment of focal hand dystonia: current status

BACKGROUND

Focal hand dystonia (FHD) is usually adult-onset focal dystonia that can be associated with marked occupational and functional disability leading to reduced quality of life.

METHODS

Relevant studies on treatment options for FHD, their limitations, and current recommendations were reviewed using the PubMed search until March 31, 2021. Besides, the reference lists of the retrieved publications were manually searched to explore other relevant studies.

RESULTS

and conclusion Currently, botulinum toxin has the best evidence for treatment of FHD, and 20-90% of patients experience symptomatic improvement. However, its benefit is often limited by the reduction of muscle tonus acting on the muscle spindle. Different surgical modalities that have been used to treat focal hand dystonia include lesional surgery, deep brain stimulation, and magnetic resonance-guided focused ultrasound thalamotomy. Recent studies exploring the role of behavioral techniques, sensorimotor training, and neuromodulation for the treatment of focal hand dystonia have reported good outcomes, but larger studies are required before implementing these interventions in practice.

Telemedicine in an Academic Movement Disorders Center during COVID-19

Objective

Telemedicine has rapidly gained momentum in movement disorder neurology during the coronavirus disease (COVID-19) pandemic to preserve clinical care while mitigating the risks of in-person visits. We present data from the rapid implementation of virtual visits in a large, academic, movement disorder practice during the COVID-19 pandemic.

Methods

We describe the strategic shift to virtual visits and retrospectively examine elements that impacted the ability to switch to telemedicine visits using historical prepandemic in-person data as a comparator, including demographics, distance driven, and diagnosis distribution, with an additional focus on patients with deep brain stimulators.

Results

A total of 686 telemedicine visits were performed over a five-week period (60% of those previously scheduled for in-office visits). The average age of participants was 65 years, 45% were female, and 73% were Caucasian. Men were more likely to make the transition (p = 0.02). Telemedicine patients lived farther from the clinic than those seen in person (66.47 km vs. 42.16 km, p < 0.001), age was not associated with making the switch, and patient satisfaction did not change. There was a significant shift in the distribution of movement disorder diagnoses seen by telemedicine compared to prepandemic in-person visits (p < 0.001). Patients with deep brain stimulators were more likely to use telemedicine (11.5% vs. 7%, p < 0.001).

Conclusion

Telemedicine is feasible, viable and relevant in the care of movement disorder patients, although health care disparities appear evident for women and minorities. Patients with deep brain stimulators preferred telemedicine in our study. Further study is warranted to explore these findings.

Can Deep Brain Stimulation Withdrawal Syndromes Be Avoided by Removing Infected Implanted Pulse Generator and Cables with Contralateral Replacement in the Same Session?

OBJECTIVE

Infections are feared complications following deep brain stimulation in 1.9 to 17.6% of cases. These infections can necessitate the removal of implants, which carries the risk of life-threatening withdrawal syndromes, especially in patients suffering from Parkinson's disease. In this report, we describe our procedure of removing an infected implanted pulse generator (IPG) and cables with contralateral replacement in the same session.

METHODS

We retrospectively analysed all patients with transpositions of an IPG and cables between 2017 and 2020 in a single-centre, university hospital setting. Medical records of all patients undergoing this particular surgical procedure were systematically reviewed. The shortest follow-up time was 12 months.

RESULTS

Between 2017 and 2020, we had 6 patients with a high risk of withdrawal syndrome in whom an infected IPG with cables was removed and replaced on the opposite side in the same session. There were postoperative complications in 2 patients: in one, the generator had to be re-affixed, and in the second, a skin transplant was required over one electrode because of skin necrosis. No case of invasive infection was seen, and the stimulation therapy was not interrupted.

CONCLUSION

One-session removal of an IPG and cables with contralateral replacement seems to be an effective therapy for patients at high risk of withdrawal syndrome.

Deep Brain Stimulation-Related Surgical Site Infections: A Systematic Review and Meta-Analysis

BACKGROUND

Over the last decades, the increased use of deep brain stimulation (DBS) has raised concerns about the potential adverse health effects of the treatment. Surgical site infections (SSIs) following an elective surgery remain a major challenge for neurosurgeons. Few studies have examined the prevalence and risk factors of DBS-related complications, particularly focusing on SSIs.

OBJECTIVES

We systematically searched published literature, up to June 2020, with no language restrictions.

MATERIALS AND METHODS

Eligible were studies that examined the prevalence of DBS-related SSIs, as well as studies that examined risk and preventive factors in relation to SSIs. We extracted information on study characteristics, follow-up, exposure and outcome assessment, effect estimate and sample size. Summary odds ratios (sOR) and 95% confidence intervals (CI) were calculated from random-effects meta-analyses; heterogeneity and small-study effects were also assessed.

RESULTS

We identified 66 eligible studies that included 12,258 participants from 27 countries. The summary prevalence of SSIs was estimated at 5.0% (95% CI: 4.0%-6.0%) with higher rates for dystonia (6.5%), as well as for newer indications of DBS, such as epilepsy (9.5%), Tourette syndrome (5.9%) and OCD (4.5%). Similar prevalence rates were found between early-onset and late-onset hardware infections. Among risk and preventive factors, the perioperative implementation of intra-wound vancomycin was associated with statistically significantly lower risk of SSIs (sOR: 0.26, 95% CI: 0.09-0.74). Heterogeneity was nonsignificant in most meta-analyses.

CONCLUSION

The present study confirms the still high prevalence of SSIs, especially for newer indications of DBS and provides evidence that preventive measures, such as the implementation of topical vancomycin, seem promising in reducing the risk of DBS-related SSIs. Large clinical trials are needed to confirm the efficacy and safety of such measures.

Radiofrequency Ablation Through Previously Effective Deep Brain Stimulation Leads for Parkinson Disease: A Retrospective Series

BACKGROUND

Although deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidus internus (GPi) is the surgical method of choice to treat the canonical symptoms of Parkinson disease, occasionally surgical sites become infected or the hardware erodes, necessitating explantation. Usual practice is to remove and reimplant replacement leads after tissue healing, leaving patients without the clinical benefits of DBS for several months, and at risk for DBS withdrawal in some, and some patients are no longer good surgical candidates for reimplantation. Radiofrequency ablation through the DBS lead is an option for these patients.

METHODS

We performed a retrospective chart review of all patients who underwent radiofrequency ablation of the STN or GPi through indwelling DBS leads performed before hardware removal at our institution. We generated patient-specific anatomic models to determine lesion locations and volumes.

RESULTS

Six patients underwent radiofrequency ablation of the STN (n = 4) and GPi (n = 2) through indwelling DBS leads. All 6 of these patients initially showed comparable motor symptom relief to that experienced with DBS before lesioning, with 4 patients sustaining meaningful long-term (≥2 years) improvement. Better outcomes were achieved in those patients with a higher percentage of the planned target lesioned.

CONCLUSIONS

Radiofrequency ablation through indwelling DBS leads before explantation could be considered a viable alternative to subsequent reimplantation or stereotactic lesion in patients with Parkinson disease in whom hardware explantation is necessary, if the patient achieved substantive symptom relief with DBS. This approach avoids symptom exacerbation while awaiting revision surgery.

Deep Brain Stimulation for Major Depression and Obsessive-Compulsive Disorder—Discontinuation of Ongoing Stimulation

Deep brain stimulation (DBS) is currently under research for the treatment of psychiatric disorders, e.g., obsessive-compulsive disorder (OCD) and treatment-resistant depression (TRD). Since the application of DBS in psychiatry has been in use for about 20 years, it is necessary to evaluate its long-term use now. A main issue in the long-term treatment of DBS concerns the effects of a discontinuation of stimulation due to intended as well as unintended reasons. In this contribution, the literature describing discontinuation effects following DBS in OCD and TRD is reviewed. Furthermore, a patient is reported in depth who experienced an unintended discontinuation of supero-lateral medial forebrain bundle (slMFB) DBS for TRD. In this case, the battery was fully depleted without the patient noticing. DBS had led to a sustained response for seven years before discontinuation of stimulation for just several weeks caused a progressive worsening of depression. Altogether, the rapid occurrence of symptom worsening, the absence of a notification about the stimulation status and the difficulties to recapture antidepressant response represent important safety aspects. For a further understanding of the described effects, time courses until worsening of depression as well as biological mechanisms need to be investigated in double-blind controlled trials.

Recommendations for Deep Brain Stimulation Device Management During a Pandemic

Most medical centers are postponing elective procedures and deferring non-urgent clinic visits to conserve hospital resources and prevent spread of COVID-19. The pandemic crisis presents some unique challenges for patients currently being treated with deep brain stimulation (DBS). Movement disorder (Parkinson’s disease, essential tremor, dystonia), neuropsychiatric disorder (obsessive compulsive disorder, Tourette syndrome, depression), and epilepsy patients can develop varying degrees of symptom worsening from interruption of therapy due to neurostimulator battery reaching end of life, device malfunction or infection. Urgent intervention to maintain or restore stimulation may be required for patients with Parkinson’s disease who can develop a rare but potentially life-threatening complication known as DBS-withdrawal syndrome. Similarly, patients with generalized dystonia can develop status dystonicus, patients with obsessive compulsive disorder can become suicidal, and epilepsy patients can experience potentially life-threatening worsening of seizures as a result of therapy cessation. DBS system infection can require urgent, and rarely emergent surgery. Elective interventions including new implantations and initial programming should be postponed. For patients with existing DBS systems, the battery status and electrical integrity interrogation can now be performed using patient programmers, and employed through telemedicine visits or by phone consultations. The decision for replacement of the implantable pulse generator to prevent interruption of DBS therapy should be made on a case-by-case basis taking into consideration battery status and a patient’s tolerance to potential therapy disruption. Scheduling of the procedures, however, depends heavily on the hospital system regulations and on triage procedures with respect to safety and resource utilization during the health crisis.

Should We Consider Deep Brain Stimulation Discontinuation in Late-Stage Parkinson's Disease?

BACKGROUND

Subthalamic deep brain stimulation (STN-DBS) effects may decrease with Parkinson's disease (PD) progression. There is no indication if, when, and how to consider the interruption of DBS treatment in late-stage PD. The objective of the current study was to investigate the percentage of "poor stimulation responders" among late-stage PD patients for elaborating an algorithm to decide whether and when DBS discontinuation may be considered.

METHODS

Late-stage PD patients (Hoehn Yahr stage ≥4 and Schwab and England Scale <50 in medication on/stimulation on condition) treated with STN-DBS for at least 5 years underwent a crossover, double-blind, randomized evaluation of acute effects of stimulation. Physicians, caregivers, and patients were blinded to stimulation conditions. Poor stimulation responders (MDS-UPDRS part III change <10% between stimulation on/medication off and stimulation off/medication off) maintained the stimulation off/medication on condition for 1 month for open-label assessment.

RESULTS

Thirty-six patients were included. The acute effect of stimulation was significant (17% MDS-UPDRS part III), with 80% of patients classified as "good responders." Seven patients were classified as "poor stimulation responders," and the stimulation was switched off, but in 4 cases the stimulation was switched back "on" because of worsening of parkinsonism and dysphagia with a variable time delay (up to 10 days). No serious adverse effects occurred.

CONCLUSIONS

The vast majority of late-stage PD patients (92%) show a meaningful response to STN-DBS. Effects of stimulation may take days to disappear after its discontinuation. We present a safe and effective decisional algorithm that could guide physicians and caregivers in making challenging therapeutic decisions in late-stage PD. © 2020 International Parkinson and Movement Disorder Society.

Surgical management of adverse events associated with deep brain stimulation: A single-center experience

Objectives:

Deep brain stimulation is widely used to treat movement disorders and selected neuropsychiatric disorders. Despite the fact, the surgical methods vary among centers. In this study, we aimed to evaluate our own surgical complications and how we performed surgical troubleshooting.

Methods:

A retrospective chart review was performed to evaluate the clinical data of patients who underwent deep brain stimulation surgery and deep brain stimulation–related procedures at our center between October 2014 and September 2019. We reviewed surgical complications and how surgical troubleshooting was performed, regardless of where the patient underwent the initial surgery.

Results:

A total of 92 deep brain stimulation lead implantation and 43 implantable pulse generator replacement procedures were performed. Among the 92 lead implantation procedures, there were two intracranial lead replacement surgeries and one deep brain stimulation lead implantation into the globus pallidus to add to existing deep brain stimulation leads in the bilateral subthalamic nuclei. Wound revision for superficial infection of the implantable pulse generator site was performed in four patients. There was neither intracerebral hemorrhage nor severe hardware infection in our series of procedures. An adaptor (extension cable) replacement was performed due to lead fracture resulting from a head trauma in two cases.

Conclusion:

We report our experience of surgical management of adverse events associated with deep brain stimulation therapy with clinical vignettes. Deep brain stimulation surgery is a safe and effective procedure when performed by a trained neurosurgeon. It is important for clinicians to be aware that there are troubles that are potentially manageable with optimal surgical treatment.

Long-term outcomes of deep brain stimulation in Parkinson disease

The efficacy of deep brain stimulation (DBS) for Parkinson disease (PD) is well established for up to 1 or 2 years, but long-term outcome data are still limited. In this Review, we critically discuss the evidence on the long-term outcomes of DBS and consider the clinical implications. Although many patients are lost to follow-up, the evidence indicates that subthalamic nucleus DBS improves motor function for up to 10 years, although the magnitude of improvement tends to decline over time. Functional scores recorded during on-medication periods worsen more quickly than those recorded in off periods, consistent with the degeneration of non-dopaminergic pathways. Dyskinesia, motor fluctuations and activities of daily living in off periods remain improved at 5 years, but quality-of-life scores have usually fallen below preoperative levels. The incidence and severity of dementia among patients receiving DBS are comparable to those among patients who receive medical treatment. Severe adverse events are rare, but adverse events such as dysarthria are common and probably under-reported. Long-term data on the outcomes of globus pallidus interna DBS are limited and mostly confirm the efficacy for dyskinesia. A trend towards offering DBS in the earlier stages of PD creates a need to identify factors that predict long-term outcomes and to discuss realistic expectations with patients preoperatively.

Malignant deep brain stimulator withdrawal syndrome

Parkinsonism-hyperpyrexia syndrome (PHS) is a neurologic potentially fatal emergency that mimics neuroleptic malignant syndrome. It commonly presents as systemic inflammatory response syndrome, acute onset worsening of muscular rigidity, autonomic instability, hyperpyrexia, confusion, diaphoresis and high creatine phosphokinase. The most common trigger for PHS is reduction or withdrawal of anti-Parkinson’s medications, especially levodopa. It was also reported in a few cases following deep brain stimulation of the subthalamic nucleus surgery shortly after anti-Parkinson’s medications were discontinued. Rare causes of PHS include deep brain stimulator (DBS) malfunction due to battery depletion. To the best of our knowledge, PHS following DBS battery depletion was reported only in three occasions. Here, we report a case of PHS due to DBS battery depletion presented as sepsis and was successfully treated with the administration of dopamine agonists, intravenous fluids and changing the DBS battery.

Life-threatening DBS withdrawal syndrome in Parkinson's disease can be treated with early reimplantation

INTRODUCTION

The deep brain stimulation (DBS) withdrawal syndrome (DBS-WDS) is a rare, life-threatening complication in Parkinson's disease (PD) patients with long disease duration and stimulation when stimulation is terminated for extended periods mostly due to infection of the DBS-hardware.

METHODS, RESULTS

In five patients explantation became necessary because of infection after a mean of 11.4 years (range 4-15 years) of DBS and a mean disease duration of 24.6 years (range 3-22 years). Mean UPDRS motor-score pre-explantation was 38 points (range 24-55 points) which increased to a mean of 78.4 points (range 58-90 points) after explantation, despite optimal Levodopa dosing. Reimplantation of the hardware after 23 days (range 3-45 days) under antibiotic treatment led to an improvement to a mean of 40 points (range 25-73 points) and a complication free survival.

CONCLUSION

Early reimplantation of the DBS-hardware is a treatment option of the DBS-WDS when the life-threatening urgency overrides surgical standards. Observation of the syndrome indicates pharmacological unresponsiveness of the dopaminergic system in advanced PD and long-term DBS.

Challenges in PD Patient Management After DBS: A Pragmatic Review

BACKGROUND

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or internal globus pallidus (GPi) represents an effective and universally applied therapy for Parkinson's disease (PD) motor complications. However, certain procedure-related problems and unrealistic patient expectations may detract specialists from indicating DBS more widely despite significant clinical effects.

METHODS

This review provides a pragmatic educational summary of the most conflicting postoperative management issues in patients undergoing DBS for PD.

RESULTS

DBS in PD has been associated with certain complications and post-procedural management issues, which can complicate surgical outcome interpretation. Many PD patients consider DBS outcomes negative due to unfulfilled expectations, even when significant motor symptom improvement is achieved. Speech, gait, postural stability, and cognition may worsen after DBS and body weight may increase. Although DBS may induce impulse control disorders in some cases, in others, it may actually improve them when dopamine agonist dosage is reduced after surgery. However, apathy may also arise, especially when dopaminergic medication tapering is rapid. Gradual loss of response with time suggests disease progression, rather than the wearing off of DBS effects. Furthermore, implantable pulse generator expiration is considered a movement disorder emergency, as it may worsen parkinsonian symptoms or cause life-threatening akinetic crises due to malignant DBS withdrawal syndrome.

CONCLUSION

Major unsolved issues occurring after DBS therapy preclude complete patient satisfaction. Multidisciplinary management at experienced centers, as well as careful and comprehensive delivery of information to patients, should contribute to make DBS outcome expectations more realistic and allow post procedural complications to be better accepted.

Life-threatening parkinsonism-hyperpyrexia syndrome following bilateral deep brain stimulation of the subthalamic nucleus

Parkinsonism-hyperpyrexia syndrome (PHS), or neuroleptic malignant syndrome (NMS), is a neurophysiologic reaction to the acute withdrawal/decrease of central dopamine levels. It is a severe complication characterized by rigidity, change in consciousness level, fever, hypertension, and autonomic instability, that can be fatal. To the best of our knowledge, PHS following deep brain stimulation (DBS) of subthalamic nucleus (STN) surgery due to anti-Parkinson drug discontinuation has been previously reported only six times. Half of these cases resulted in fatalities. Herein, we report on an early diagnosed case of PHS following bilateral STN-DBS which was successfully treated with the administration of dopamine agonists, fluid replacement, and activation of DBS.

Seventy Years with the Globus Pallidus: Pallidal Surgery for Movement Disorders Between 1947 and 2017

The year 2017 marks the 70th anniversary of the birth of human stereotactic neurosurgery. The first procedure was a pallidotomy for Huntington's disease. However, it was for Parkinson's disease that pallidotomy was soon adopted worldwide. Pallidotomy was abandoned in the late 1950s in favor of thalamotomy because of the latter's more striking effect on tremor. The advent of levodopa put a halt to all surgery for PD. In the mid-1980s, Laitinen reintroduced the posteroventral pallidotomy of Leksell, and this procedure spread worldwide thanks to its efficacy on most parkinsonian symptoms including levodopa-induced dyskinesias and thanks to basic scientific work confirming the role of the globus pallidus internus in the pathophysiology of PD. With the advent of deep brain stimulation of the subthalamic nucleus, pallidotomy was again abandoned, and even DBS of the GPi has been overshadowed by STN DBS. The GPi reemerged in the late 1990s as a major stereotactic target for DBS in dystonia and, recently, in Tourette syndrome. Lately, lesioning of the GPI is being proposed to treat refractory status dystonicus or to treat DBS withdrawal syndrome in PD patients. Hence, the pallidum as a stereotactic target for either lesioning or DBS has been the phoenix of functional stereotactic neurosurgery, constantly abandoned and then rising again from its ashes. This review is a tribute to the pallidum on its 70th anniversary as a surgical target for movement disorders, analyzing its ebbs and flows and highlighting its merits, its versatility, and its resilience. © 2017 International Parkinson and Movement Disorder Society.

Whether to Proceed With Deep Brain Stimulator Battery Change in a Patient With Signs of Potential Sepsis and Parkinson Hyperpyrexia Syndrome: A Case Report

Parkinsonism-hyperpyrexia syndrome (PHS) is a neurologic emergency associated with anti- Parkinson medication withdrawal; however, its clinical presentation mimics sepsis. We describe the case of a 69-year-old man with advanced Parkinson disease who presented for exchange of the depleted battery in his subthalamic deep brain stimulator. The patient's preoperative symptoms of fever, rigidity, altered consciousness, and autonomic instability presented a dilemma whether to proceed with battery exchange to treat PHS or postpone surgery due to potential sepsis. The administration of dopaminergic medications, dantrolene, and antipyretic drugs are temporary supportive measures, while prompt restoration of deep brain stimulator function is the most important therapeutic treatment for PHS.

Malignant Subthalamic Nucleus-Deep Brain Stimulation Withdrawal Syndrome in Parkinson's Disease

Abrupt cessation of STN-DBS is an under-recognized cause of life-threatening akinetic crisis in Parkinson's disease (PD) and can present as a movement disorder emergency. We report on 2 patients who survived severe and prolonged akinetic crisis after abrupt cessation of STN stimulation for PD (malignant STN-DBS withdrawal syndrome). We discuss the clinical similarities and possible differences in pathophysiology from the akinetic crisis in medically-treated PD. Although early implantable pulse generator (IPG) replacement is the definitive treatment, medical and economic considerations may preclude early surgery and strategies for medical management assume importance. We reflect upon the socioeconomic concerns surrounding DBS in countries lacking health care coverage and the need for user-independent monitors and indicators of low IPG battery status.