Historical developments in children's deep brain stimulation

Towards new perspectives: International consensus guidance on dystonia in pediatric palliative care

BACKGROUND

Pediatric dystonias are associated with a broad spectrum of etiologies, resulting in a heterogeneous patient population in whom clinical presentation, evolution, and therapeutic needs may differ. These neurological symptoms are particularly common in children and adolescents with life-limiting and life-threatening conditions requiring pediatric palliative care (PPC). The impact on the child's quality of life is significant, as is distress for caregivers. Addressing and alleviating dystonia is key to providing good palliative care; however, there is limited evidence. A greater recognition and management of dystonia in this setting is urgently needed to provide appropriate interventions and care.

OBJECTIVES

To develop a standardized approach to dystonia in PPC.

MATERIALS AND METHODS

A two-round Delphi process explored the views of experts on the definition, assessment, monitoring, and treatment of dystonia in PPC. Professionals from different backgrounds and disciplines were invited worldwide. The final panel comprised 71 participants who completed a multi-statement online questionnaire.

RESULTS

Fifty-three items were endorsed, providing expert, consensus-based recommendations.

CONCLUSIONS

The limited clinical knowledge of childhood dystonia represents a challenge, especially in children with palliative care needs. This study is a first international consensus on dystonia in PPC and offers novel approaches to improving the dystonia-related burden and advancing clinical practice in this vulnerable population.

Knowledge and practice of deep brain stimulation among pediatric neurology residents in Saudi Arabia

Deep brain stimulation (DBS) is an established neurosurgical intervention for movement disorders, yet awareness among Saudi pediatric neurology residents remains limited. This study assessed the knowledge, attitudes, and perceived barriers to DBS among Saudi pediatric neurology trainees. A cross-sectional survey was conducted among pediatric neurology residents in Saudi Arabia. Participants completed a structured questionnaire assessing their familiarity with DBS indications, procedural knowledge, and training exposure. Descriptive and inferential statistics were applied. A total of 40 pediatric neurology residents participated, with a majority (87.5%) aged 26-30 years and 57.5% being women. While 65% recognized DBS as FDA-approved for adults, only 50% were aware of its pediatric approval. Knowledge of DBS targets was moderate (65%), but awareness of side effects (45%) and genetic factors influencing DBS outcomes (32.5%) was limited. Exposure to DBS-related activities was minimal, with 95% never attending a family discussion, 100% never witnessing a DBS surgery, and 80% never attending a DBS lecture. Higher residency years correlated with better DBS knowledge (P = 0.001), and prior patient referral was associated with higher scores (P = 0.028). Awareness and training in DBS among Saudi pediatric neurology residents are suboptimal. Integrating DBS education into residency curricula may improve competency and clinical decision-making.

Bridging the Gap in FDA Approval for Pediatric Neuromodulation Devices

While neuromodulation devices for managing neurological conditions have significantly advanced, there remains a substantial gap in FDA-approved devices specifically designed for pediatric patients. Devices like deep brain stimulators (DBS), vagus nerve stimulators (VNS), and spinal cord stimulators (SCS) are primarily approved for adults, with few options for children. To meet pediatric needs, off-label use is common; however, unique challenges to pediatric device development-such as ethical concerns, small trial populations, and financial disincentives due to the limited market size-continue to hinder progress. This review examines these barriers to pediatric neuromodulation device development and FDA (Food and Drug Administration) approval, as well as the current efforts, such as FDA initiatives and consortia support, that address regulatory and financial challenges. Furthermore, we discuss pathways like the Humanitarian Device Exemptions and Real-World Evidence programs that aim to streamline the approval process and address unmet clinical needs in pediatric care. Addressing these barriers could expand access to effective neuromodulation treatments and improve patient care.

Application of deep brain stimulation for the treatment of childhood-onset dystonia in patients with MEPAN syndrome

Introduction

Mitochondrial Enoyl CoA Reductase Protein-Associated Neurodegeneration (MEPAN) syndrome is a rare inherited metabolic condition caused by MECR gene mutations. This gene encodes a protein essential for fatty acid synthesis, and defects cause progressively worsening childhood-onset dystonia, optic atrophy, and basal ganglia abnormalities. Deep brain stimulation (DBS) has shown mixed improvement in other childhood-onset dystonia conditions. To the best of our knowledge, DBS has not been investigated as a treatment for dystonia in patients with MEPAN syndrome.

Methods

Two children with MEPAN were identified as possible DBS candidates due to severe generalized dystonia unresponsive to pharmacotherapy. Temporary depth electrodes were placed in six locations bilaterally and tested during a 6-day hospitalization to determine the best locations for permanent electrode placement. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and Barry-Albright Dystonia Scale (BADS) were used for preoperative and postoperative testing to quantitatively assess dystonia severity changes. Patient 1 had permanent electrodes placed at the globus pallidus internus (GPi) and pedunculopontine nucleus (PPN). Patient 2 had permanent electrodes placed at the GPi and ventralis intermedius nucleus of the thalamus (VIM).

Results

Both patients successfully underwent DBS placement with no perioperative complications and significant improvement in their BFMDRS score. Patient 2 also demonstrated improvement in the BADS.

Discussion

We demonstrated a novel application of DBS in MEPAN syndrome patients with childhood-onset dystonia. These patients showed clinically significant improvements in dystonia following DBS, indicating that DBS can be considered for dystonia in patients with rare metabolic disorders that currently have no other proven treatment options.

Clinical and Psychosocial Factors Considered When Deciding Whether to Offer Deep Brain Stimulation for Childhood Dystonia

INTRODUCTION

Childhood dystonia is often nonresponsive to medications, and refractory cases are increasingly being treated with deep brain stimulation (DBS). However, many have noted that there is little consensus about when DBS should be offered, and there has been little examination of clinicians' decision-making process when determining whether to offer DBS for childhood dystonia.

OBJECTIVES

This study aimed to identify and examine the factors considered by pediatric movement disorder specialists before offering DBS.

MATERIALS AND METHODS

Semistructured interviews (N = 29) with pediatric dystonia clinicians were conducted, transcribed, and coded. Using thematic content analysis, nine central themes were identified when clinicians were asked about key factors, clinical factors, and psychosocial factors considered before offering pediatric DBS.

RESULTS

Clinicians identified nine main factors. Five of these were classified primarily as clinical factors: early intervention and younger age (raised by 86% of respondents), disease progression and symptom severity (83%), etiology and genetic status (79%), clinicians' perceived risks and benefits of DBS for the patient (79%), and exhaustion of other treatment options (55%). The remaining four were classified primarily as psychosocial factors: social and family support (raised by 97% of respondents), patient and caregiver expectations about outcomes and understanding of DBS treatment (90%), impact of dystonia on quality of life (69%), and financial resources and access to care (31%).

CONCLUSIONS

Candidacy determinations, in this context, are complicated by an interrelation of clinical and psychosocial factors that contribute to the decision. There is potential for bias when considering family support and quality of life. Uncertainty of outcomes related to the etiology of dystonia makes candidacy judgments challenging. More systematic examination of the characteristics and criteria used to identify pediatric patients with dystonia who can significantly benefit from DBS is necessary to develop clear guidelines and promote the well-being of these children.

Neurosurgical management of non-spastic movement disorders

BACKGROUND

Non-spastic movement disorders in children are common, although true epidemiologic data is difficult to ascertain. Children are more likely than adults to have hyperkinetic movement disorders defined as tics, dystonia, chorea/athetosis, or tremor. These conditions manifest from acquired or heredodegenerative etiologies and often severely limit function despite medical and surgical management paradigms. Neurosurgical management for these conditions is highlighted.

METHODS

We performed a focused review of the literature by searching PubMed on 16 May 2023 using key terms related to our review. No temporal filter was applied, but only English articles were considered. We searched for the terms (("Pallidotomy"[Mesh]) OR "Rhizotomy"[Mesh]) OR "Deep Brain Stimulation"[Mesh], dystonia, children, adolescent, pediatric, globus pallidus, in combination. All articles were reviewed for inclusion in the final reference list.

RESULTS

Our search terms returned 37 articles from 2004 to 2023. Articles covering deep brain stimulation were the most common (n = 34) followed by pallidotomy (n = 3); there were no articles on rhizotomy.

DISCUSSION

Non-spastic movement disorders are common in children and difficult to treat. Most of these patients are referred to neurosurgery for the management of dystonia, with modern neurosurgical management including pallidotomy, rhizotomy, and deep brain stimulation. Historically, pallidotomy has been effective and may still be preferred in subpopulations presenting either in status dystonicus or with high risk for hardware complications. Superiority of DBS over pallidotomy for secondary dystonia has not been determined. Rhizotomy is an underutilized surgical tool and more study characterizing efficacy and risk profile is indicated.

Deep Brain Stimulation for Pediatric Dystonia: Clinicians' Perspectives on the Most Pressing Ethical Challenges

INTRODUCTION

Pediatric deep brain stimulation (pDBS) is commonly used to manage treatment-resistant primary dystonias with favorable results and more frequently used for secondary dystonia to improve quality of life. There has been little systematic empirical neuroethics research to identify ethical challenges and potential solutions to ensure responsible use of DBS in pediatric populations.

METHODS

Clinicians (n = 29) who care for minors with treatment-resistant dystonia were interviewed for their perspectives on the most pressing ethical issues in pDBS.

RESULTS

Using thematic content analysis to explore salient themes, clinicians identified four pressing concerns: (1) uncertainty about risks and benefits of pDBS (22/29; 72%) that poses a challenge to informed decision-making; (2) ethically navigating decision-making roles (15/29; 52%), including how best to integrate perspectives from diverse stakeholders (patient, caregiver, clinician) and how to manage surrogate decisions on behalf of pediatric patients with limited capacity to make autonomous decisions; (3) information scarcity effects on informed consent and decision quality (15/29; 52%) in the context of patient and caregivers' expectations for treatment; and (4) narrow regulatory status and access (7/29; 24%) such as the lack of FDA-approved indications that contribute to decision-making uncertainty and liability and potentially limit access to DBS among patients who may benefit from it.

CONCLUSION

These results suggest that clinicians are primarily concerned about ethical limitations of making difficult decisions in the absence of informational, regulatory, and financial supports. We discuss two solutions already underway, including supported decision-making to address uncertainty and further data sharing to enhance clinical knowledge and discovery.

Thalamo-cortical and cerebello-cortical functional connectivity in development

The thalamus is a critical relay center for neural pathways involving sensory, motor, and cognitive functions, including cortico-striato-thalamo-cortical and cortico-ponto-cerebello-thalamo-cortical loops. Despite the importance of these circuits, their development has been understudied. One way to investigate these pathways in human development in vivo is with functional connectivity MRI, yet few studies have examined thalamo-cortical and cerebello-cortical functional connectivity in development. Here, we used resting-state functional connectivity to measure functional connectivity in the thalamus and cerebellum with previously defined cortical functional networks in 2 separate data sets of children (7-12 years old) and adults (19-40 years old). In both data sets, we found stronger functional connectivity between the ventral thalamus and the somatomotor face cortical functional network in children compared with adults, extending previous cortico-striatal functional connectivity findings. In addition, there was more cortical network integration (i.e. strongest functional connectivity with multiple networks) in the thalamus in children than in adults. We found no developmental differences in cerebello-cortical functional connectivity. Together, these results suggest different maturation patterns in cortico-striato-thalamo-cortical and cortico-ponto-cerebellar-thalamo-cortical pathways.

Deep brain stimulation effect in genetic dyskinetic cerebral palsy: The case of ADCY5- related disease

BACKGROUND

Cerebral Palsy (CP) represents a frequent cause of disability in childhood. Early in life, genetic disorders may present with motor dysfunction and diagnosed as CP. Establishing the primary, genetic etiology allows more accurate prognosis, genetic counselling, and planning for symptomatic interventions in homogeneous etiological groups. Deep brain stimulation (DBS) is recommended in refractory movement disorders, including isolated pediatric dystonias. For dystonia evolving in more complex associations in genetic CP, the effect of DBS is still understudied and currently only sporadically described.

OBJECTIVES

To report the effect of DBS applied to the globus pallidus pars interna (GPi) in children with complex movement disorders caused by pathogenic ADCY5 variants, diagnosed as dyskinetic CP previous to genetic diagnostic.

METHODS

We conducted a retrospective study on evolution of treatment with DBS in ADCY5-related disease. A standardized proforma including the different type of movement disorders and associated neurological signs was completed at each follow-up time, based on video recordings, as well as functional assessments used in children with CP.

RESULTS

Four children (mean of age, 13 ± 2.9 years) received GPi-DBS. The same de novo pathogenic missense variant (c.1252C > T, p.R418W) was identified in three out of four and a splice site variant (c.2088 + 2G > T) in one subject. Developmental delay and overlapping features including axial hypotonia, chorea, dystonic attacks, myoclonus, and cranial dyskinesia were present. The median age at DBS was 9 years and follow-up with DBS, 2.6 years. We identified a pattern of clinical response with early suppression of dystonic attacks, followed by improvement of myoclonus and facial dyskinesia. Effect on chorea was delayed and more limited. Two patients gained notable functional benefit related to sitting, standing, gait, use of upper limbs and speech.

CONCLUSION

ADCY5-related disease may benefit from GPi-DBS. The most significant clinical response relates to the early and sustained benefit on dystonic attacks and a variable but still positive response on the other hyperkinetic features. Genetic etiology of CP will contribute to further elucidate genotype-phenotype correlations and to refine DBS indication as network-related symptomatic interventions.

GPi DBS treatment outcome in children with monogenic dystonia: a case series and review of the literature

Introduction

Dystonia is the third most common pediatric movement disorder and is often difficult to treat. Deep brain stimulation (DBS) of the internal pallidum (GPi) has been demonstrated as a safe and effective treatment for genetic dystonia in adolescents and adults. The results of DBS in children are limited to individual cases or case series, although it has been proven to be an effective procedure in carefully selected pediatric cohorts. The aim of our study was to present the treatment outcome for 7- to 9-year-old pediatric patients with disabling monogenic isolated generalized DYT-THAP1 and DYT-KMT2B dystonia after bilateral GPi-DBS.

Patients and results

We present three boys aged <10 years; two siblings with disabling generalized DYT-THAP1 dystonia and a boy with monogenic-complex DYT-KMT2B. Dystonia onset occurred between the ages of 3 and 6. Significantly disabled children were mostly dependent on their parents. Pharmacotherapy was inefficient and patients underwent bilateral GPi-DBS. Clinical signs of dystonia improved significantly in the first month after the implantation and continued to maintain improved motor functions, which were found to have improved further at follow-up. These patients were ambulant without support and included in everyday activities. All patients had significantly lower Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) values, indicating >25% improvement over the first 15 months. However, there was a decline in speech and upper limb function, manifesting with bradylalia, bradykinesia, and dysphonia, which decreased after treatment with trihexyphenidyl.

Conclusion

Although reports of patients with monogenic dystonia, particularly DYT-THAP1, treated with DBS are still scarce, DBS should be considered as an efficient treatment approach in children with pharmacoresistent dystonia, especially with generalized monogenic dystonia and to prevent severe and disabling symptoms that reduce the quality of life, including emotional and social aspects. Patients require an individual approach and parents should be properly informed about expectations and possible outcomes, including relapses and impairments, in addition to DBS responsiveness and related improvements. Furthermore, early genetic diagnosis and the provision of appropriate treatments, including DBS, are mandatory for preventing severe neurologic impairments.

Deep Brain Stimulation for Pediatric Dystonia: A Review of the Literature and Suggested Programming Algorithm

Deep brain stimulation (DBS) is an established intervention for use in pediatric movement disorders, especially dystonia. Although multiple publications have provided guidelines for deep brain stimulation patient selection and programming in adults, there are no evidence-based or consensus statements published for pediatrics. The result is lack of standardized care and underutilization of this effective treatment. To this end, we assembled a focus group of 13 pediatric movement disorder specialists and 1 neurosurgeon experienced in pediatric deep brain stimulation to review recent literature and current practices and propose a standardized approach to candidate selection, implantation target site selection, and programming algorithms. For pediatric dystonia, we provide algorithms for (1) programming for initial session and follow-up sessions, and (2) troubleshooting side effects encountered during programming. We discuss common side effects, how they present, and recommendations for management. This topical review serves as a resource for movement disorders specialists interested in using deep brain stimulation for pediatric dystonia.

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.

Women in Neuromodulation: Innovative Contributions to Stereotactic and Functional Neurosurgery

Stereotactic neurosurgery emerged in the mid-20th century following the development of a stereotactic frame by Spiegel and Wycis. Historically women were underrepresented in clinical and academic neurosurgery. There is still a significant deficit of female scientists in this field. This article aims to demonstrate the career and scientific work of some of the most important women who contributed to the development of stereotactic and functional neurosurgery. Exceptional women from all over the world, represented in this review, assisted the evolution of modern stereotactic and functional neurosurgery as neurosurgeons, neuropathologists, neurologists, neurophysiologists and occupational therapists. Fortunately, we could conclude that in the last two decades the number of female researchers has increased significantly.

Starting a DBS service for children: It's not the latitude but the attitude - Establishment of the paediatric DBS centre in Northern Finland

OBJECTIVE

Paediatric movement disorder patients can benefit from deep brain stimulation (DBS) treatment and it should be offered in a timely manner. In this paper we describe our experience establishing a DBS service for paediatric patients.

METHODS

We set out to establish a paediatric DBS (pDBS) procedure in Oulu University Hospital in northern Finland, where up to this point DBS treatment for movement disorders had been available for adult patients. Collaboration with experienced centres aided in the process.

RESULTS

A multidisciplinary team was assembled and a systematic protocol for patient evaluation and treatment was created, with attention to special features of the regional health care system. All of our first paediatric patients had very severe movement disorders, which is typical for a new DBS centre. The patients benefitted from pDBS treatment despite variable aetiologies of movement disorders, which included cerebral palsy and rare genetic disorders with variants in PDE10A, TPK1 and ARX. We also present our high-quality paediatric MR-imaging protocol with tractography.

CONCLUSIONS

Establishment of a pDBS centre requires expertise in classification of paediatric movement disorders, longstanding experience in adult DBS and a committed multidisciplinary team. Besides high-quality imaging and a skilled neurosurgery team, careful patient selection, realistic treatment goals and experience in rehabilitation are imperative in pDBS treatment.

Deep Brain Stimulation for Pediatric Dystonia

Dystonia is one of the most common pediatric movement disorders and can have a profound impact on the lives of children and their caregivers. Response to pharmacologic treatment is often unsatisfactory. Deep brain stimulation (DBS) has emerged as a promising treatment option for children with medically refractory dystonia. In this review we highlight the relevant literature related to DBS for pediatric dystonia, with emphasis on the background, indications, prognostic factors, challenges, and future directions of pediatric DBS.

Perceptions of Deep Brain Stimulation for Adolescents with Obsessive-Compulsive Disorder

Objective: The present study aims to understand perceptions of deep brain stimulation (DBS) for severe obsessive-compulsive disorder (OCD) in adolescents among two groups: parents of children with a history of OCD and adults with a history of OCD. Methods: Two hundred sixty participants completed a questionnaire exploring their treatment history, relevant symptom severity, DBS knowledge, and DBS attitudes using an acceptability scale and a series of statements indicating levels of willingness or reluctance to consider DBS for adolescents with severe OCD or severe epilepsy. Results: Overall, participants found DBS to be fairly acceptable for adolescents with severe OCD, with 63% reporting at least 7/10 on a 0-10 acceptability Likert scale. Respondents were more willing to consider DBS for epilepsy than for OCD. Several factors were associated with greater willingness to consider DBS for OCD, including familiarity with DBS, the presence of suicidal thoughts, assurances of daily functioning improvements, and assurances of substantial symptom reduction. Concerns about safety, personality changes, and long-term effects on the body were associated with greatest reluctance to consider DBS for OCD. Conclusions: Our findings support the importance of increasing parents' familiarity with DBS, monitoring factors participants identified as most important to their DBS perceptions in future DBS research, and communicating benefits and risks clearly. We also highlight the need for further research on perceptions of DBS for severe and refractory OCD in adolescents.

Deep brain stimulation versus pallidotomy for status dystonicus: a single-center case series

OBJECTIVE

First-line pharmacological therapies have shown limited efficacy in status dystonicus (SD), while surgery is increasingly reported as remediable in refractory cases. In this context, there is no evidence regarding which neurosurgical approach is the safest and most effective. The aim of this study was to assess the clinical outcomes and surgery-related complications of globus pallidus internus deep brain stimulation (GPi DBS) and pallidotomy for the treatment of drug-resistant SD.

METHODS

The authors reviewed the records of patients with drug-resistant SD who had undergone GPi DBS or pallidotomy at their institution between 2003 and 2017. The severity of the dystonia was evaluated using the Barry-Albright Dystonia (BAD) Scale. Surgical procedures were performed bilaterally in all cases.

RESULTS

Fourteen patients were eligible for inclusion in the study. After surgery, the mean follow-up was 40.6 ± 30 months. DBS ended the dystonic storm in 87.5% of cases (7/8), while pallidotomy had a success rate of 83.3% (5/6). No significant differences were observed between the two techniques in terms of failure rates (risk difference DBS vs pallidotomy -0.03, 95% CI -0.36 to 0.30), SD mean resolution time (DBS 34.8 ± 19 days, pallidotomy 21.8 ± 20.2 days, p > 0.05), or BAD scores at each postoperative follow-up (p > 0.05). The long-term hardware complication rate after DBS was 37.5%, whereas no surgery-related complications were noted following pallidotomy.

CONCLUSIONS

The study data suggest that DBS and pallidotomy are equally safe and effective therapies for drug-resistant SD. The choice between the two techniques should be tailored on a case-by-case basis, depending on factors such as the etiology and evolution pattern of the underlying dystonia and the clinical conditions at the moment of SD onset. Given the limitation of the low statistical power of this study, further multicentric investigations are needed to confirm its findings.

Post-mortem histopathology of a pediatric brain after bilateral DBS of GPI for status dystonicus: case report and review of the literature

PURPOSE

To investigate the effects of deep brain stimulation (DBS) electrodes on the brain of a dystonic pediatric patient submitted to bilateral DBS of the globus pallidus internus (GPI).

METHODS

An 8-year-old male patient underwent bilateral DBS of GPI for status dystonicus. He died 2 months later due to multiorgan failure triggered by bacterial pneumonia. A post-mortem pathological study of the brain was done.

RESULTS

At visual inspection, no grossly apparent softening, hemorrhage, or necrosis of the brain adjacent to the DBS lead tracts was detected. High-power microscopic examination of the tissue surrounding the electrode trajectories showed lymphocyte infiltration, astrocytic gliosis, microglia, macrophages, and clusters of multinucleate giant cells. Significant astrocytosis was confirmed by GFAP staining in the electrode site. The T cell lymphocyte activity was overexpressed with activated macrophages detected with CD3, CD20, CD45, and CD68 stains respectively. There was no gliosis or leukocyte infiltration away from the surgical tracks of the electrodes.

CONCLUSION

This is the first post-mortem examination of a child's brain after bilateral DBS of GPI. The comparison with adult post-mortem reports showed no significant differences and confirms the safety of DBS implantation in the pediatric population too.

Deep Brain Stimulation of the Internal Pallidum in Lesch-Nyhan Syndrome: Clinical Outcomes and Connectivity Analysis

BACKGROUND

Lesch-Nyhan syndrome (LNS) is a rare genetic disorder characterized by a deficiency of hypoxanthine-guanine phosphoribosyltransferase enzyme. It manifests during infancy with compulsive self-mutilation behavior associated with disabling generalized dystonia and dyskinesia. Clinical management of these patients poses an enormous challenge for medical teams and carers.

OBJECTIVES

We report our experience with bilateral deep brain stimulation (DBS) of the globus pallidus internus (GPi) in the management of this complex disorder.

MATERIALS AND METHODS

Preoperative and postoperative functional assessment data prospectively collected by a multidisciplinary pediatric complex motor disorders team, including imaging, neuropsychology, and neurophysiology evaluations were analyzed with regards to motor and behavioral control, goal achievement, and patient and caregivers' expectations.

RESULTS

Four male patients (mean age 13 years) underwent DBS implantation between 2011 and 2018. Three patients received double bilateral DBS electrodes within the posteroventral GPi and the anteromedial GPi, whereas one patient had bilateral electrodes placed in the posteroventral GPi only. Median follow-up was 47.5 months (range 22-98 months). Functional improvement was observed in all patients and discussed in relation to previous reports. Analysis of structural connectivity revealed significant correlation between the involvement of specific cortical regions and clinical outcome.

CONCLUSION

Combined bilateral stimulation of the anteromedial and posteroventral GPi may be considered as an option for managing refractory dystonia and self-harm behavior in LNS patients. A multidisciplinary team-based approach is essential for patient selection and management, to support children and families, to achieve functional improvement and alleviate the overall disease burden for patients and caregivers.

Deep brain stimulation in pediatric dystonia: a systematic review

While deep brain stimulation (DBS) treatment is relatively rare in children, it may have a role in dystonia to reduce motor symptoms and disability. Pediatric DBS studies are sparse and limited by small sample size, and thus, outcomes are poorly understood. Thus, we performed a systematic review of the literature including studies of DBS for pediatric (age < 21) dystonia. Patient demographics, disease causes and characteristics, motor scores, and disability scores were recorded at baseline and at last post-operative follow-up. We identified 19 studies reporting DBS outcomes in 76 children with dystonia. Age at surgery was 13.8 ± 3.9 (mean ± SD) years, and 58% of individuals were male. Post-operative follow-up duration was 2.8 ± 2.8 years. Sixty-eight percent of patients had primary dystonia (PD), of whom 56% had a pathological mutation in DYT1 (DYT1+). Across all patients, regardless of dystonia type, 43.8 ± 36% improvement was seen in Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) motor (-M) scores after DBS, while 43.7 ± 31% improvement was observed in BFMDRS disability (-D) scores. Patients with PD were more likely to experience ≥ 50% improvement (56%) in BFMDRS-M scores compared to patients with secondary causes of dystonia (21%, p = 0.004). DYT1+ patients were more likely to achieve ≥ 50% improvement (65%) in BFMDRS-D than DTY1- individuals (29%, p = 0.02), although there was no difference in BFMDRS-M ≥ 50% improvement rates between DYT1+ (66%) or DYT1- (43%) children (p = 0.11). While DBS is less common in pediatric patients, individuals with severe dystonia may receive worthwhile benefit with neuromodulation treatment.

DBS: a compelling example for ethical and legal reflection-a French perspective on ethical and legal concerns about DBS

Deep brain stimulation (DBS) is an approved treatment for neurological diseases and a promising one for psychiatric conditions, which may produce spectacular results very quickly. It is also a powerful tool for brain research and exploration. Beyond an overview of the ethical and legal literature on this topic, this paper aims at showing that DBS is a compelling example for ethical-legal reflection, as it combines a highly technical surgical procedure, a complex active medical device and neuromodulation of the human brain to restore lost abilities caused by a chronic and evolving disease. Some of the ethical and legal issues raised by DBS are not specific, but shed new light on medical ethics and law. Others are more DBS-specific, as they are linked to the intricacies of research and treatment, to the need to tune the device, to the patients' control over the device and its effects and to the involvement of family caregivers.

Parental Attitudes Toward Deep Brain Stimulation in Adolescents with Treatment-Resistant Conditions

Objective: To examine parent's perceptions of deep brain stimulation (DBS) and whether DBS is perceived to be a viable and safe treatment for their adolescent child presenting with a severe, treatment-resistant neurological or psychiatric condition. Method: Two hundred and seventy-nine parents completed an online survey using Amazon Mechanical Turk (MTurk). Participants were presented with five vignette scenarios involving adolescents with severe, treatment-resistant neurological or psychiatric conditions: Rett syndrome, autism spectrum disorder, epilepsy, obsessive-compulsive disorder, and Tourette syndrome. Parents were then asked to evaluate each scenario and rate overall acceptability of using DBS to improve their child's core symptoms. Data were collected over a period of 2 weeks in the month of October 2018. Results: We found that parents reported favorable impressions of DBS regardless of the target condition, especially when greater improvement could be assured and when their child had the capacity to assist in the treatment decision-making. Parents indicated some reluctance to use DBS when possible safety concerns were present. Familiarity with DBS was directly associated with attitudes. Conclusions: The findings highlight an overall parental willingness to consider DBS as a treatment option for key symptoms of neurological and psychiatric conditions in adolescents.

Pallidal Deep Brain Stimulation in DYT6 Dystonia: Clinical Outcome and Predictive Factors for Motor Improvement

Pallidal deep brain stimulation is an established treatment in dystonia. Available data on the effect in DYT-THAP1 dystonia (also known as DYT6 dystonia) are scarce and long-term follow-up studies are lacking. In this retrospective, multicenter follow-up case series of medical records of such patients, the clinical outcome of pallidal deep brain stimulation in DYT-THAP1 dystonia, was evaluated. The Burke Fahn Marsden Dystonia Rating Scale served as an outcome measure. Nine females and 5 males were enrolled, with a median follow-up of 4 years and 10 months after implant. All benefited from surgery: dystonia severity was reduced by a median of 58% (IQR 31-62, p = 0.001) at last follow-up, as assessed by the Burke Fahn Marsden movement subscale. In the majority of individuals, there was no improvement of speech or swallowing, and overall, the effect was greater in the trunk and limbs as compared to the cranio-cervical and orolaryngeal regions. No correlation was found between disease duration before surgery, age at surgery, or preoperative disease burden and the outcome of deep brain stimulation. Device- and therapy-related side-effects were few. Accordingly, pallidal deep brain stimulation should be considered in clinically impairing and pharmaco-resistant DYT-THAP1 dystonia. The method is safe and effective, both short- and long-term.

Surgical Tone Reduction in Cerebral Palsy

This article overviews the surgical options for hypertonia management in cerebral palsy, both spasticity and dystonia. We review the history and use of intrathecal baclofen. We contrast its use with the indications for selective dorsal rhizotomy and review how it is the optimal technique to lower tone in the ambulatory spastic diplegic patient with cerebral palsy. This article reviews the advent of deep brain stimulation, with an emphasis on selection criteria and expected outcomes in this population. The article reviews the principles and use of selective peripheral neurotomy as it is applied to focal spasticity not requiring systemic tone reduction.

A Review of Neurostimulation for Epilepsy in Pediatrics

Neurostimulation for epilepsy refers to the application of electricity to affect the central nervous system, with the goal of reducing seizure frequency and severity. We review the available evidence for the use of neurostimulation to treat pediatric epilepsy, including vagus nerve stimulation (VNS), responsive neurostimulation (RNS), deep brain stimulation (DBS), chronic subthreshold cortical stimulation (CSCS), transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS). We consider possible mechanisms of action and safety concerns, and we propose a methodology for selecting between available options. In general, we find neurostimulation is safe and effective, although any high quality evidence applying neurostimulation to pediatrics is lacking. Further research is needed to understand neuromodulatory systems, and to identify biomarkers of response in order to establish optimal stimulation paradigms.

Clinical phenotypes associated with outcomes following deep brain stimulation for childhood dystonia

OBJECTIVE

Although deep brain stimulation (DBS) is an accepted treatment for childhood dystonia, there is significant heterogeneity in treatment response and few data are available to identify ideal surgical candidates.

METHODS

Data were derived from a systematic review and individual patient data meta-analysis of DBS for dystonia in children that was previously published. Outcomes were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale for movement (BFMDRS-M) and for disability (BFMDRS-D). The authors used partial least squares, bootstrapping, and permutation statistics to extract patterns of contributions of specific preoperative characteristics to relationship with distinct outcomes, in all patients and in patients with primary and secondary dystonia separately.

RESULTS

Of 301 children undergoing DBS for dystonia, 167 had primary dystonia, 125 secondary dystonia, and 9 myoclonus dystonia. Three dissociable preoperative phenotypes (latent variables) were identified and associated with the following: 1) BFMDRS-M at last follow-up; 2) relative change in BFMDRS-M score; and 3) relative change in BFMDRS-D score. The phenotype of patients with secondary dystonia, with a high BFMDRS-M score and truncal involvement, undergoing DBS at a younger age, was associated with a worse postoperative BFMDRS-M score. Children with primary dystonia involving the trunk had greater improvement in BFMDRS-M and -D scores. Those with primary dystonia of shorter duration and proportion of life with disease, undergoing globus pallidus DBS, had greater improvements in BFMDRS-D scores at long-term follow-up.

CONCLUSIONS

In a comprehensive, data-driven, multivariate analysis of DBS for childhood dystonia, the authors identified novel and dissociable patient phenotypes associated with distinct outcomes. The findings of this report may inform surgical candidacy for DBS.

Deep brain stimulation for pediatric dystonia: a meta-analysis with individual participant data

AIM

We performed a meta-analysis with individual participant data of deep brain stimulation (DBS) for dystonia in children and young people.

METHOD

Three databases (PubMed, Embase, and Web of Science) were queried from January 1999 to August 2017 with no language restrictions to identify case studies and cohort studies reporting on pediatric patients (age ≤21y) with dystonia. The primary outcomes were changes in Burke-Fahn-Marsden (BFM) or Barry-Albright Dystonia Scale scores. A mixed-effects regression was used to identify associations between clinical covariates and outcomes.

RESULTS

Of 2509 citations reviewed, 72 articles (321 children) were eligible. At last follow-up (median 12mo, 25th centile=9.0; 75th centile=32.2), 277 (86.3%) patients showed improvement in dystonia, while 66.1 percent showed clinically significant (>20%) BFM Dystonia Rating Scale-motor improvement. On multivariable hierarchical regression, older age at dystonia onset, inherited dystonia without nervous system pathology and idiopathic dystonia (vs inherited with nervous system pathology or acquired dystonia), and truncal involvement indicated a better outcome (p<0.05).

INTERPRETATION

The data suggest that DBS is effective and should be considered in selected children with inherited or idiopathic dystonia.

WHAT THIS PAPER ADDS

Deep brain stimulation is effective in selected children with inherited or idiopathic dystonia.

Case Report: Targeting for Deep Brain Stimulation Surgery Using Chronic Recording and Stimulation in an Inpatient Neuromodulation Monitoring Unit, With Implantation of Electrodes in GPi and Vim in a 7-Year-Old Child With Progressive Generalized Dystonia

BACKGROUND

Deep brain stimulation for secondary dystonia has been limited by unknown optimal targets for individual children.

OBJECTIVES

We report the first case of a 7-year-old girl with severe generalized dystonia due to acquired striatal necrosis in whom we used a new method for identifying targets for deep brain stimulation.

METHODS

We implanted temporary depth electrodes in 5 different nuclei bilaterally in the basal ganglia and thalamus, with test stimulation and recording during 1 week while the child was an inpatient in a neuromodulation monitoring unit.

RESULTS

Single-unit activity in ventral intermedius Vim, internal globus pallidus (GPi), and subthalamic (STN) nuclei occurred during dystonic spasms and correlated with electromyography. Stimulation in Vim eliminated dystonic spasms. Subsequent implantation of 4 permanent deep brain stimulation electrodes in bilateral Vim and Gpi nuclei resolved dystonic spasms.

CONCLUSION

The use of temporary stimulation and recording electrodes to identify deep brain stimulation targets is a promising new technique that could improve outcomes in children with acquired dystonia.

Frameless robot-assisted pallidal deep brain stimulation surgery in pediatric patients with movement disorders: precision and short-term clinical results

OBJECTIVE

The purpose of this study was to verify the safety and accuracy of the Neuromate stereotactic robot for use in deep brain stimulation (DBS) electrode implantation for the treatment of hyperkinetic movement disorders in childhood and describe the authors' initial clinical results.

METHODS

A prospective evaluation of pediatric patients with dystonia and other hyperkinetic movement disorders was carried out during the 1st year after the start-up of a pediatric DBS unit in Barcelona. Electrodes were implanted bilaterally in the globus pallidus internus (GPi) using the Neuromate robot without the stereotactic frame. The authors calculated the distances between the electrodes and their respective planned trajectories, merging the postoperative CT with the preoperative plan using VoXim software. Clinical outcome was monitored using validated scales for dystonia and myoclonus preoperatively and at 1 month and 6 months postoperatively and by means of a quality-of-life questionnaire for children, administered before surgery and at 6 months' follow-up. We also recorded complications derived from the implantation technique, "hardware," and stimulation.

RESULTS

Six patients aged 7 to 16 years and diagnosed with isolated dystonia ( DYT1 negative) (3 patients), choreo-dystonia related to PDE2A mutation (1 patient), or myoclonus-dystonia syndrome SGCE mutations (2 patients) were evaluated during a period of 6 to 19 months. The average accuracy in the placement of the electrodes was 1.24 mm at the target point. At the 6-month follow-up, patients showed an improvement in the motor (65%) and functional (48%) components of the Burke-Fahn-Marsden Dystonia Rating Scale. Patients with myoclonus and SGCE mutations also showed an improvement in action myoclonus (95%-100%) and in functional tests (50%-75%) according to the Unified Motor-Rating Scale. The Neuro-QOL score revealed inconsistent results, with improvement in motor function and social relationships but worsening in anxiety, cognitive function, and pain. The only surgical complication was medial displacement of the first electrode, which limited intensity of stimulation in the lower contacts, in one case.

CONCLUSIONS

The Neuromate stereotactic robot is an accurate and safe tool for the placement of GPi electrodes in children with hyperkinetic movement disorders.

DBS in pediatric patients: institutional experience

INTRODUCTION

DBS is initially used for treatment of essential tremor and Parkinson's disease in adults. In 1996, a child with severe life-threatening dystonia was offered DBS to the internal globus pallidus (GPi) with lasting efficacy at 20 years. Since that time, increasing number of children benefited from DBS.

PATIENTS AND METHODS

We retrospectively evaluated our database of patients who underwent DBS from 2011 to 2017. All patients ≤ 17 years of age at the time of implantation of DBS were included in this series. Subjective Benefit Rating Scale (SBRS), Hoehn Yahr Scale (HYS), Fahn Marsden Rating Scale (FMRS), Clinical Global Impressions Scales (CGI), and Yale Global Tic Severity Scale (YGT) were used to evaluate clinical outcome.

RESULTS

Between May 2014 and October 2017, 11 children underwent DBS procedure in our institution. Six of them were female and five of them were male. Mean age at surgery was 11.8 ± 4.06 years (range 5-17 years). In our series, four patients had primary dystonia (PDY) (36.3%), three patients had secondary dystonia (SDY) (27.2%), two patients had JP (18.1%), and two patients had Tourette Syndrome (TS) (18.1%). Two JP patients underwent bilateral STN DBS while the other nine patients underwent bilateral GPi DBS. SBRS scores were 1.75 ± 0.5 for patients with PDY, 3 ± 0 for patients with JP, 2.5 ± 0.7 for patients with TS, and 2 ± 1 for patients with SDY. Mean FMRS reduction rate was 40.5 for patients with dystonia. Significant improvement was also defined in patients with TS and JP after DBS. None of the patients experienced any intracerebral hemorrhage or other serious adverse neurological effect related to the DBS. Wound complications occurred in two patients.

CONCLUSION

There are many literatures that support DBS as a treatment option for pediatric patients with medically refractory neurological disorders. DBS has replaced ablative procedures as a treatment of choice not only for adult patients, but also for pediatric patients. Wound-related complications still remain the most common problem in pediatric patients. Development of smaller and more flexible hardware will improve quality of children's life and minimize wound-related complications in the future.

Therapeutic Applications of Invasive Neuromodulation in Children and Adolescents

Although the application of noninvasive brain stimulation methods to children and adolescents has been frequently studied in depression, autism spectrum disorder, attention-deficit/hyperactivity disorder, and other neuropsychiatric disorders, invasive methods such as deep brain stimulation (DBS) and vagal nerve stimulation (VNS) have received less attention. DBS and VNS have demonstrated utility in young patients especially for dystonia and epilepsy. VNS has FDA clearance for intractable epilepsy in patients aged 4 years and older. Further measured work with invasive neuromodulation for children and adolescents with debilitating neuropsychiatric disorders could provide new treatment options and expand current knowledge base of neurocircuitry across development.

Pediatric Deep Brain Stimulation Using Awake Recording and Stimulation for Target Selection in an Inpatient Neuromodulation Monitoring Unit

Deep brain stimulation (DBS) for secondary (acquired, combined) dystonia does not reach the high degree of efficacy achieved in primary (genetic, isolated) dystonia. We hypothesize that this may be due to variability in the underlying injury, so that different children may require placement of electrodes in different regions of basal ganglia and thalamus. We describe a new targeting procedure in which temporary depth electrodes are placed at multiple possible targets in basal ganglia and thalamus, and probing for efficacy is performed using test stimulation and recording while children remain for one week in an inpatient Neuromodulation Monitoring Unit (NMU). Nine Children with severe secondary dystonia underwent the NMU targeting procedure. In all cases, 4 electrodes were implanted. We compared the results to 6 children who had previously had 4 electrodes implanted using standard intraoperative microelectrode targeting techniques. Results showed a significant benefit, with 80% of children with NMU targeting achieving greater than 5-point improvement on the Burke–Fahn–Marsden Dystonia Rating Scale (BFMDRS), compared with 50% of children using intraoperative targeting. NMU targeting improved BFMDRS by an average of 17.1 whereas intraoperative targeting improved by an average of 10.3. These preliminary results support the use of test stimulation and recording in a Neuromodulation Monitoring Unit (NMU) as a new technique with the potential to improve outcomes following DBS in children with secondary (acquired) dystonia. A larger sample size will be needed to confirm these results.

Clinical Approach to a Child with Movement Disorders

Assessing movement can be especially challenging in children. Refined yet flexible observational examination skills and utilization of established phenomenological approaches are essential in distinguishing normal from abnormal movements in the developing child and reaching an appropriate diagnosis. Mastering such skill requires an appreciation of the unique features of the developing motor system and an understanding of key concepts underlying normal motor development in children. Establishing a trusting therapeutic relationship with the patient and family, minimizing anxiety, and utilizing observation and distraction during physical examination are essential to successful diagnosis and management.

Pharmacological and neurosurgical interventions for managing dystonia in cerebral palsy: a systematic review

AIM

To systematically review evidence for pharmacological/neurosurgical interventions for managing dystonia in individuals with cerebral palsy (CP) to inform a care pathway.

METHOD

Searches included studies with a minimum of five participants with dystonia in CP receiving oral baclofen, benzodiazepines (clonazepam, diazepam, lorazepam), clonidine, gabapentin, levodopa, trihexyphenidyl, botulinum toxin, intrathecal baclofen (ITB), or deep brain stimulation (DBS). Evidence was classified according to American Academy of Neurology guidelines.

RESULTS

Twenty-eight articles underwent data extraction: one levodopa, five trihexyphenidyl, three botulinum toxin, six ITB, and 13 DBS studies. No articles for oral baclofen, benzodiazepines, clonidine, or gabapentin met the inclusion criteria. Evidence for reducing dystonia was level C (possibly effective) for ITB and DBS; level C (possibly ineffective) for trihexyphenidyl; and level U (inadequate data) for botulinum toxin.

INTERPRETATION

For dystonia reduction, ITB and DBS are possibly effective, whereas trihexyphenidyl was possibly ineffective. There is insufficient evidence to support oral medications or botulinum toxin to reduce dystonia. There is insufficient evidence for pharmacological and neurosurgical interventions to improve motor function, decrease pain, and ease caregiving. The majority of the pharmacological and neurosurgical management of dystonia in CP is based on clinical expert opinion.

WHAT THIS PAPER ADDS

Intrathecal baclofen and deep brain stimulation are possibly effective in reducing dystonia. Current evidence does not support effectiveness of oral medications or botulinum toxin to reduce dystonia. Evidence is inadequate for pharmacological/neurosurgical interventions impact on improving motor function, pain/comfort, and easing caregiving. The majority of the care pathway rests on expert opinion.

Diagnosis and treatment of pediatric onset isolated dystonia

Isolated dystonia refers to a genetic heterogeneous group of progressive conditions with onset of symptoms during childhood or adolescence, progressive course with frequent generalization and marked functional impairment. There are well-known monogenic forms of isolated dystonia with pediatric onset such as DYT1 and DYT6 transmitted with autosomal dominant inheritance and low penetrance. Genetic findings of the past years have widened the etiological spectrum and the phenotype. The recently discovered genes (GNAL, ANO-3, KTM2B) or variant of already known diseases, such as Ataxia-Teleangectasia, are emerging as another causes of pediatric onset dystonia, sometimes with a more complex phenotype, but their incidence is unknown and still a considerable number of cases remains genetically undetermined. Due to the severe disability of pediatric onset dystonia treatment remains unsatisfactory and still mainly based upon oral pharmacological agents. However, deep brain stimulation is now extensively applied with good to excellent results especially when patients are treated early during the course of the disease.

Basic and Translational Neuroscience of Childhood-Onset Dystonia: A Control-Theory Perspective

Dystonia is a collection of symptoms with involuntary muscle activation causing hypertonia, hyperkinetic movements, and overflow. In children, dystonia can have numerous etiologies with varying neuroanatomic distribution. The semiology of dystonia can be explained by gain-of-function failure of a feedback controller that is responsible for stabilizing posture and movement. Because postural control is maintained by a widely distributed network, many different anatomic regions may be responsible for symptoms of dystonia, although all features of dystonia can be explained by uncontrolled activation or hypersensitivity of motor cortical regions that can cause increased reflex gain, inserted postures, or sensitivity to irrelevant sensory variables. Effective treatment of dystonia in children requires an understanding of the relationship between etiology, anatomy, and the specific mechanism of failure of postural stabilization.

Dystonic storm: a practical clinical and video review

Dystonic storm is a frightening hyperkinetic movement disorder emergency. Marked, rapid exacerbation of dystonia requires prompt intervention and admission to the intensive care unit. Clinical features of dystonic storm include fever, tachycardia, tachypnea, hypertension, sweating and autonomic instability, often progressing to bulbar dysfunction with dysarthria, dysphagia and respiratory failure. It is critical to recognize early and differentiate dystonic storm from other hyperkinetic movement disorder emergencies. Dystonic storm usually occurs in patients with known dystonia, such as DYT1 dystonia, Wilson’s disease and dystonic cerebral palsy. Triggers such as infection or medication adjustment are present in about one-third of all events. Due to the significant morbidity and mortality of this disorder, we propose a management algorithm that divides decision making into two periods: the first 24 h, and the next 2–4 weeks. During the first 24 h, supportive therapy should be initiated, and appropriate patients should be identified early as candidates for pallidal deep brain stimulation or intrathecal baclofen. Management in the next 2–4 weeks aims at symptomatic dystonia control and supportive therapies.

Considerations in deep brain stimulation (DBS) for pediatric secondary dystonia

PURPOSE

There is a paucity of effective long-term medication treatment for secondary dystonias. In situations where significantly impairing secondary dystonias fail to respond to typical enteral medications and intrathecal (or even intraventricular) baclofen, consideration should be given to the use of deep brain stimulation (DBS). While Level I evidence and long-term follow-up clearly demonstrate the efficacy of DBS for primary dystonia, the evidence for secondary dystonia remains mixed and unclear. In this study, we report our experience with pediatric subjects who have undergone DBS for secondary dystonia.

METHODS

We discuss the indications and outcomes of DBS procedures completed at our center. We also present a detailed discussion of the considerations in the management of these patients as well as a literature review.

RESULTS

Of the four cases retrospectively examined here, all subjects experienced reductions in the severity of their dystonia (ranging from 0 to 100% on both the Barry-Albright Dystonia (BAD) and Burke-Fahn-Marsden Dystonia Rating Scale-Motor (BFMDRS-M) scales).

CONCLUSIONS

Pallidal DBS should be considered among children with functionally debilitating, medication-resistant secondary dystonia. Patients without fixed skeletal deformities who have experienced a short duration of symptoms are most likely to benefit from this intervention.

Bilateral globus pallidus internus deep brain stimulation for dyskinetic cerebral palsy supports success of cochlear implantation in a 5-year old ex-24 week preterm twin with absent cerebellar hemispheres

BACKGROUND

Early onset dystonia (dyskinesia) and deafness in childhood pose significant challenges for children and carers and are the cause of multiple disability. It is particularly tragic when the child cannot make use of early cochlear implantation (CI) technology to relieve deafness and improve language and communication, because severe cervical and truncal dystonia brushes off the magnetic amplifier behind the ears. Bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) neuromodulation can reduce dyskinesia, thus supporting CI neuromodulation success.

METHODS

We describe the importance of the order of dual neuromodulation surgery for dystonia and deafness. First with bilateral GPi DBS using a rechargeable ACTIVA-RC neurostimulator followed 5 months later by unilateral CI with a Harmony (BTE) Advanced Bionics Hi Res 90 K cochlear device. This double neuromodulation was performed in series in a 12.5 kg 5 year-old ex-24 week gestation-born twin without a cerebellum.

RESULTS

Relief of dyskinesia enabled continuous use of the CI amplifier. Language understanding and communication improved. Dystonic storms abated. Tolerance of sitting increased with emergence of manual function. Status dystonicus ensued 10 days after ACTIVA-RC removal for infection-erosion at 3 years and 10 months. He required intensive care and DBS re-implantation 3 weeks later together with 8 months of hospital care. Today he is virtually back to the level of functioning before the DBS removal in 2012 and background medication continues to be slowly weaned.

CONCLUSION

This case illustrates that early neuromodulation with DBS for dystonic cerebral palsy followed by CI for deafness is beneficial. Both should be considered early i.e. under the age of five years. The DBS should precede the CI to maximise dystonia reduction and thus benefits from CI. This requires close working between the paediatric DBS and CI services.

The International Classification of Functioning (ICF) to evaluate deep brain stimulation neuromodulation in childhood dystonia-hyperkinesia informs future clinical & research priorities in a multidisciplinary model of care

The multidisciplinary team (MDT) approach illustrates how motor classification systems, assessments and outcome measures currently available have been applied to a national cohort of children and young people with dystonia and other hyperkinetic movement disorders (HMD) particularly with a focus on dyskinetic cerebral palsy (CP). The paper is divided in 3 sections. Firstly, we describe the service model adopted by the Complex Motor Disorders Service (CMDS) at Evelina London Children's Hospital and King's College Hospital (ELCH-KCH) for deep brain stimulation. We describe lessons learnt from available dystonia studies and discuss/propose ways to measure DBS and other dystonia-related intervention outcomes. We aim to report on current available functional outcome measures as well as some impairment-based assessments that can encourage and generate discussion among movement disorders specialists of different backgrounds regarding choice of the most important areas to be measured after DBS and other interventions for dystonia management. Finally, some recommendations for multi-centre collaboration in regards to functional clinical outcomes and research methodologies for dystonia-related interventions are proposed.

Recognizing the Common Origins of Dystonia and the Development of Human Movement: A Manifesto of Unmet Needs in Isolated Childhood Dystonias

Dystonia in childhood may be severely disabling and often unremitting and unrecognized. Considered a rare disorder, dystonic symptoms in childhood are pervasive in many conditions including disorders of developmental delay, cerebral palsy (CP), autism, neurometabolic, neuroinflammatory, and neurogenetic disorders. Collectively, there is a need to recognize the role of early postures and movements which characterize phases of normal fetal, infant, and child development as a backdrop to the many facets of dystonia in early childhood neurological disorders and to be aware of the developmental context of dystonic symptoms. The role of cocontraction is explored throughout infancy, childhood, young adulthood, and in the elderly. Under-recognition of pervasive dystonic disorders of childhood, including within CP is reviewed. Original descriptions of CP by Gowers are reviewed and contemporary physiological demonstrations are used to illustrate support for an interpretation of the tonic labyrinthine response as a manifestation of dystonia. Early recognition and molecular diagnosis of childhood dystonia where possible are desirable for appropriate clinical stratification and future precision medicine and functional neurosurgery where appropriate. A developmental neurobiological perspective could also be useful in exploring new clinical strategies for adult-onset dystonia disorders focusing on environmental and molecular interactions and systems behaviors.