Emerging therapies for childhood-onset movement disorders

PURPOSE OF REVIEW

We highlight novel and emerging therapies in the treatment of childhood-onset movement disorders. We structured this review by therapeutic entity (small molecule drugs, RNA-targeted therapeutics, gene replacement therapy, and neuromodulation), recognizing that there are two main approaches to treatment: symptomatic (based on phenomenology) and molecular mechanism-based therapy or 'precision medicine' (which is disease-modifying).

RECENT FINDINGS

We highlight reports of new small molecule drugs for Tourette syndrome, Friedreich's ataxia and Rett syndrome. We also discuss developments in gene therapy for aromatic l-amino acid decarboxylase deficiency and hereditary spastic paraplegia, as well as current work exploring optimization of deep brain stimulation and lesioning with focused ultrasound.

SUMMARY

Childhood-onset movement disorders have traditionally been treated symptomatically based on phenomenology, but focus has recently shifted toward targeted molecular mechanism-based therapeutics. The development of precision therapies is driven by increasing capabilities for genetic testing and a better delineation of the underlying disease mechanisms. We highlight novel and exciting approaches to the treatment of genetic childhood-onset movement disorders while also discussing general challenges in therapy development for rare diseases. We provide a framework for molecular mechanism-based treatment approaches, a summary of specific treatments for various movement disorders, and a clinical trial readiness framework.

MR-guided focused ultrasound in movement disorders and beyond: Lessons learned and new frontiers

The development of MR-guided focused ultrasound (MRgFUS) has provided a new therapeutic tool for neuropsychiatric disorders. In contrast to previously available neurosurgical techniques, MRgFUS allows precise impact on deep brain structures without the need for incision and yields an immediate effect. In its high-intensity modality (MRgHIFU), it produces accurate therapeutic thermoablation in previously selected brain targets. Importantly, the production of the lesion is progressive and highly controlled in real-time by both neuroimaging and clinical means. MRgHIFU ablation is already an accepted and widely used treatment for medically-refractory Parkinson's disease and essential tremor. Notably, other neurological disorders and diverse brain targets, including bilateral treatments, are currently under examination. Conversely, the low-intensity modality (MRgLIFU) shows promising prospects in neuromodulation and transient blood-brain barrier opening (BBBO). In the former circumstance, MRgLIFU could serve as a powerful clinical and research tool for non-invasively modulating brain activity and function. BBBO, on the other hand, emerges as a potentially impactful method to influence disease pathogenesis and progression by increasing brain target engagement of putative therapeutic agents. While promising, these applications remain experimental. As a recently developed technology, MRgFUS is not without challenges and questions to be addressed. Further developments and broader experience are necessary to enhance MRgFUS capabilities in both research and clinical practice, as well as to define device constraints. This clinical mini-review aims to provide an overview of the main evidence of MRgFUS application and to highlight unmet needs and future potentialities of the technique.

Protocol for combined N-of-1 trials to assess cerebellar neurostimulation for movement disorders in children and young adults with dyskinetic cerebral palsy

BACKGROUND

Movement and tone disorders in children and young adults with cerebral palsy are a great source of disability. Deep brain stimulation (DBS) of basal ganglia targets has a major role in the treatment of isolated dystonias, but its efficacy in dyskinetic cerebral palsy (DCP) is lower, due to structural basal ganglia and thalamic damage and lack of improvement of comorbid choreoathetosis and spasticity. The cerebellum is an attractive target for DBS in DCP since it is frequently spared from hypoxic ischemic damage, it has a significant role in dystonia network models, and small studies have shown promise of dentate stimulation in improving CP-related movement and tone disorders.

METHODS

Ten children and young adults with DCP and disabling movement disorders with or without spasticity will undergo bilateral DBS in the dorsal dentate nucleus, with the most distal contact ending in the superior cerebellar peduncle. We will implant Medtronic Percept, a bidirectional neurostimulator that can sense and store brain activity and deliver DBS therapy. The efficacy of cerebellar DBS in improving quality of life and motor outcomes will be tested by a series of N-of-1 clinical trials. Each N-of-1 trial will consist of three blocks, each consisting of one month of effective stimulation and one month of sham stimulation in a random order with weekly motor and quality of life scales as primary and secondary outcomes. In addition, we will characterize abnormal patterns of cerebellar oscillatory activity measured by local field potentials from the intracranial electrodes related to clinical assessments and wearable monitors. Pre- and 12-month postoperative volumetric structural and functional MRI and diffusion tensor imaging will be used to identify candidate imaging markers of baseline disease severity and response to DBS.

DISCUSSION

Our goal is to test a cerebellar neuromodulation therapy that produces meaningful changes in function and well-being for people with CP, obtain a mechanistic understanding of the underlying brain network disorder, and identify physiological and imaging-based predictors of outcomes useful in planning further studies.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06122675, first registered November 7, 2023.

Current opinions and practices in post-stroke movement disorders: Survey of movement disorders society members

BACKGROUND

Post-stroke movement disorders (PSMD) encompass a wide array of presentations, which vary in mode of onset, phenomenology, response to treatment, and natural history. There are no evidence-based guidelines on the diagnosis and treatment of PSMD.

OBJECTIVES

To survey current opinions and practices on the diagnosis and treatment of PSMD.

METHODS

A survey was developed by the PSMD Study Group, commissioned by the International Parkinson's and Movement Disorders Society (MDS). The survey, distributed to all members, yielded a total of 529 responses, 395 (74.7%) of which came from clinicians with experience with PSMD.

RESULTS

Parkinsonism (68%), hemiballismus/hemichorea (61%), tremor (58%), and dystonia (54%) were by far the most commonly endorsed presentation of PSMD, although this varied by region. Basal ganglia stroke (76% of responders), symptoms contralateral to stroke (75%), and a temporal relationship (59%) were considered important factors for the diagnosis of PSMD. Oral medication use depended on the phenomenology of the PSMD. Almost 50% of respondents considered deep brain stimulation and ablative surgeries as options for treatment. The lack of guidelines for the diagnosis and treatment was considered the most important gap to address.

CONCLUSIONS

Regionally varying opinions and practices on PSMD highlight gaps in (and mistranslation of) epidemiologic and therapeutic knowledge. Multicenter registries and prospective community-based studies are needed for the creation of evidence-based guidelines to inform the diagnosis and treatment of patients with PSMD.

[Drug-induced movement disorders : nosology and treatment]

Movements disorders are frequently encountered in general practice and emergency departments and are in many cases of iatrogenic origin. Dopamine D2 receptor blocking agents (DRBA), mainly neuroleptics, are most often incriminated. These drug-induced movement disorders (DIMD) can be classified according to the kinetics of the manifestations (acute DIMD and tardive syndromes), the phenomenology of the abnormal movements observed or depending on the pharmacological agent involved. The diagnosis is based on the time course of the events, clinical examination and meticulous anamnesis of the patient's previous and current treatments. Management is always based on the interruption of the suspected causal treatment when possible. Some cases have a severe prognosis and require immediate treatment.

Deep brain stimulation for movement disorders treatment in Africa: The current status, outcomes, and challenges

Movement disorders (MDs), a diverse group of neurological conditions characterized by abnormal and involuntary movements, have a profound impact on individuals, families, and healthcare systems. Deep Brain Stimulation (DBS) has emerged as a promising therapeutic intervention, offering relief from symptoms and improved quality of life. By implanting electrodes in specific brain regions and connecting them to a pulse generator, DBS modulates aberrant neural activity underlying these disorders. While DBS has gained recognition globally, its utilization in African countries remains limited. This comprehensive article presents the results of a literature review on the status of DBS therapy for MDs in Africa. The review assesses treatment outcomes, patient demographics, and challenges tied to implementing DBS in the African context. The findings reveal promising developments in DBS therapy across several African countries, particularly in treating Parkinson's disease and dystonia. However, challenges related to awareness, access to specialized care, and a scarcity of expertise still impede broader adoption. The article underscores the urgent need for collaborative efforts, policy changes, and increased training to expand the reach of DBS therapy, thus mitigating the burden of MDs on the African continent.

Paraneoplastic movement disorders

Paraneoplastic movement disorders are diverse autoimmune neurological illnesses occurring in the context of systemic cancer, either in isolation or as part of a multifocal neurological disease. Movement phenomena may be ataxic, hypokinetic (parkinsonian), or hyperkinetic (myoclonus, chorea, or other dyskinetic disorders). Some disorders mimic neurodegenerative or hereditary illnesses. The subacute onset and coexisting nonclassic features of paraneoplastic disorders aid distinction. Paraneoplastic autoantibodies provide further information regarding differentiating cancer association, disease course, and treatment responses. A woman with cerebellar ataxia could have metabotropic glutamate receptor 1 autoimmunity, in the setting of Hodgkin lymphoma, a mild neurological phenotype and response to immunotherapy. A different woman, also with cerebellar ataxia, could have Purkinje cytoplasmic antibody type 1 (anti-Yo), accompanying ovarian adenocarcinoma, a rapidly progressive phenotype and persistent disabling deficits despite immune therapy. The list of antibody biomarkers is growing year-on-year, each with its own ideal specimen type for detection (serum or CSF), accompanying neurological manifestations, cancer association, treatment response, and prognosis. Therefore, a profile-based approach to screening both serum and CSF is recommended. Immune therapy trials are generally undertaken, and include one or more of corticosteroids, IVIg, plasma exchange, rituximab, or cyclophosphamide. Symptomatic therapies can also be employed for hyperkinetic disorders.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

Clinical Trial Registration: PROSPERO (CRD42022335436).

Spasticity and movement disorders in cerebral palsy

PURPOSE

To review the neurosurgical treatments of children with movement disorders associated with cerebral palsy (CP) during the previous decades, up to the present day.

METHODS

An extensive literature review was undertaken to identify important publications about this subject. My experience treating children with these disorders over the past three decades was included in the individual sections.

RESULTS

Peripheral neurotomies have been developed for children with focal spasticity. For those with spastic paraparesis, selective lumbar rhizotomies were developed, and for those with spastic quadriparesis, intrathecal baclofen infusions were developed. Both effectively alleviate spasticity in the affected extremities. Generalized dystonia associated with CP has been treated with deep brain stimulation with mild improvement, but treatment with intrathecal baclofen and intraventricular baclofen improve those movements markedly. No effective treatment has been reported for children with athetoid CP. For those with choreiform CP, deep brain stimulation may be effective but intrathecal baclofen does not appear to be.

CONCLUSION

Treatment of children with movement disorders associated with CP increased slowly in the 1970s and 1980s but accelerated rapidly in the 1990s with the introduction of lumbar dorsal rhizotomies and intrathecal baclofen. In the last 30 years, tens of thousands of children with spasticity and movement disorders associated with CP have been treated by pediatric neurosurgeons, and their care has become an integral component of current pediatric neurosurgical practice.

Cerebellar deep brain stimulation for the treatment of movement disorders in cerebral palsy

OBJECTIVE

Cerebral palsy (CP) represents the most common childhood physical disability that encompasses disorders of movement and posture attributed to nonprogressive disturbances that occurred in the developmental fetal or infant brain. Dyskinetic CP (DCP), the second most common type of CP after spastic forms, refers to a subset of patients in whom dystonia and choreoathetosis are the predominant motor manifestations. Most children with CP have abnormal brain MRI studies indicative of cortical and deep gray matter damage consistent with hypoxic ischemic encephalopathy, which may preclude or suggest decreased efficacy of standard deep brain stimulation (DBS) targets. The cerebellum has been posited as an attractive target for treatment of DCP because it is frequently spared from hypoxic ischemic damage and has shown promise in alleviating patient symptoms both in early work in the 1970s and in more recent case series with DBS.

METHODS

The authors performed bilateral cerebellar DBS implantation, targeting the dentate nucleus (DN) and cerebellar outflow pathway, in 3 patients with DCP. Leads were connected to a pulse generator that senses local field potentials during chronic continuous DBS. The authors report their surgical methods, examples of chronic cerebellar local field potential recordings, and preliminary clinical outcomes. Motor outcomes were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale.

RESULTS

Three patients 14-22 years old with DCP and MRI evidence of structural damage to the basal ganglia were offered cerebellar stimulation targeting the DN. All patients tolerated the procedure well and demonstrated improvement in subjective motor function as well as objective improvement in the Burke-Fahn-Marsden Dystonia Rating Scale movement subscale, although the range of responses was variable (19%-40%). Patients experienced subjective improvement in motor function including ease of hand movements and coordination, gait, head control, speech, decreased overflow, and diminished muscle tightness.

CONCLUSIONS

DBS of the dentate nuclei in patients with DCP appears to be safe and shows preliminary evidence of clinical benefit. New chronic sensing technology may allow for determination of in vivo mechanisms of network disruption in DCP and allow for further understanding of the effects of neuromodulation on brain physiology. Larger studies with long-term follow up will be required to further elucidate the clinical benefits of this therapy. This report addresses a gap in the literature regarding the technical approach to image-based stereotactic targeting and chronic neural recording in the DN.

Long-Term Follow-Up of Pediatric Patients with Dyskinetic Cerebral Palsy and Deep Brain Stimulation

BACKGROUND

Deep brain stimulation (DBS) has been increasingly used in the management of dyskinetic cerebral palsy (DCP). Data on long-term effects and the safety profile are rare.

OBJECTIVES

We assessed the efficacy and safety of pallidal DBS in pediatric patients with DCP.

METHODS

The STIM-CP trial was a prospective, single-arm, multicenter study in which patients from the parental trial agreed to be followed-up for up to 36 months. Assessments included motor and non-motor domains.

RESULTS

Of the 16 patients included initially, 14 (mean inclusion age 14 years) were assessed. There was a significant change in the (blinded) ratings of the total Dyskinesia Impairment Scale at 36 months. Twelve serious adverse events (possibly) related to treatment were documented.

CONCLUSION

DBS significantly improved dyskinesia, but other outcome parameters did not change significantly. Investigations of larger homogeneous cohorts are needed to further ascertain the impact of DBS and guide treatment decisions in DCP. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Restless Legs Syndrome and Other Common Sleep-Related Movement Disorders

OBJECTIVE

This article reviews common sleep-related movement disorders, including their clinical description, epidemiology, pathophysiology (if known), and evaluation and management strategies. This article will provide the reader with a good foundation for approaching concerns that are suggestive of sleep-related movement disorders to properly evaluate and manage these conditions.

LATEST DEVELOPMENTS

α2δ Ligands, such as gabapentin enacarbil, can be used for the initial treatment of restless legs syndrome (RLS) or in those who cannot tolerate, or have developed augmentation to, dopamine agonists. Another option is the rotigotine patch, which has a 24-hour treatment window and may be beneficial for those who have developed augmentation with short-acting dopamine agonists. IV iron can improve RLS symptoms even in those whose serum ferritin level is between 75 ng/mL and 100 ng/mL. At serum ferritin levels greater than 75 ng/mL, oral iron will likely have minimal absorption or little effect on the improvement of RLS. Research has found an association between RLS and cardiovascular disease, particularly in people who have periodic limb movements of sleep.

ESSENTIAL POINTS

RLS is the most common sleep-related movement disorder. Its pathophysiology is likely a combination of central iron deficiency, dopamine overproduction, and possibly cortical excitation. Treatment includes oral or IV iron. Dopaminergic medications can be very effective but often lead to augmentation, which limits their long-term use. Other sleep-related movement disorders to be aware of are sleep-related rhythmic movement disorder, nocturnal muscle cramps, sleep-related propriospinal myoclonus, sleep bruxism, and benign myoclonus of infancy.

Evidence and Recommendation for Guanidinoacetate Methyltransferase Deficiency Newborn Screening

Guanidinoacetate methyltransferase (GAMT) deficiency is an autosomal recessive disorder of creatine biosynthesis due to pathogenic variants in the GAMT gene that lead to cerebral creatine deficiency and neurotoxic levels of guanidinoacetate. Untreated, GAMT deficiency is associated with hypotonia, significant intellectual disability, limited speech development, recurrent seizures, behavior problems, and involuntary movements. The birth prevalence of GAMT deficiency is likely between 0.5 and 2 per million live births. On the basis of small case series and sibling data, presymptomatic treatment with oral supplements of creatine, ornithine, and sodium benzoate, and a protein-restricted diet to reduce arginine intake, appear to substantially improve health and developmental outcomes. Without newborn screening, diagnosis typically happens after the development of significant impairment, when treatment has limited utility. GAMT deficiency newborn screening can be incorporated into the tandem-mass spectrometry screening that is already routinely used for newborn screening, with about 1 per 100 000 newborns screening positive. After a positive screen, diagnosis is established by finding an elevated guanidinoacetate concentration and low creatine concentration in the blood. Although GAMT deficiency is significantly more rare than other conditions included in newborn screening, the feasibility of screening, the low number of positive results, the relative ease of diagnosis, and the expected benefit of presymptomatic dietary therapy led to a recommendation from the Advisory Committee on Heritable Disorders in Newborns and Children to the Secretary of Health and Human Services that GAMT deficiency be added to the Recommended Uniform Screening Panel. This recommendation was accepted in January 2023.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[Networkmodulation through deep brain stimulation]

BACKGROUND

Deep brain stimulation (DBS) is widely performed since 1987, mainly in the realm of movement disorders.

AIM

To provide an overview of the current state of DBS in various neuropsychiatric disorders and to provide an overview of new developments.

METHOD

Narrative review of recent literature.

RESULTS

Several studies have shown the potential of DBS for carefully selected patients suffering from refractory neuropsychiatic indications such as Tourette syndrome, obsessive-compulsive disorder, depression, and Alzheimer’s disease. Applying for a CE or FDA approval by the implant manufacturer by means of double-blinded controlled trials has become highly cumbersome because of the new stricter European medical device regulation. For these RCTs to be successful, a sufficiently long follow-up time and the neurosurgeon’s knowledge of the most optimal stimulation point are required. The latest technical advances focussing on network stimulation have greatly added to defining this optimal stimulation point per disease.

CONCLUSION

DBS is a safe technique with a proven effect on more than 200,000 patients with movement disorders. Trials into the application of DBS for the most important psychiatric and cognitive indications are important.

Movement disorders in children: recognition and management in the emergency department

The differential diagnosis for pediatric patients presenting to the emergency department with movement-based neurological complaints is wide. Clinicians must ensure these children receive an appropriate evaluation to recognize rare diseases. Early recognition of these diagnoses helps facilitate coordination with specialists, guides imaging, and ensures proper management and disposition. This issue reviews 3 less-common movement disorders: acute cerebellar ataxia, anti-N-methyl-D-aspartate receptor encephalitis, and acute disseminated encephalomyelitis. The common presentations, evaluation, and management of these conditions in the emergency department are discussed.

Childhood Neurologic Conditions: Movement Disorders

Most movement disorders in children are hyperkinetic. The most common type is tic disorders, which can involve motor and phonic tics and are classified as simple or complex. Motor or phonic tics that persist for more than 1 year are defined as persistent (chronic) tic disorder. Tourette syndrome can be diagnosed if a child has multiple motor tics and at least one phonic tic for more than 1 year with onset before age 18 years. Children with Tourette syndrome may have symptoms of attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, depression, or behavioral disorders. Chorea can be seen as a symptom of rheumatic fever (Sydenham chorea), in children with a history of kernicterus, and in dyskinetic cerebral palsy. Chorea also may be part of an underlying metabolic or genetic condition. Dystonia is characterized by repetitive contortions and posturing of the limbs and body. It can be isolated or part of an underlying neurologic condition. Tremor can occur as a manifestation of essential tremor or can be an enhanced physiologic tremor exacerbated by drugs, illness, or stimulants. Ataxia most often is seen as a postinfectious or postvaccination acute cerebellar ataxia. Progressive ataxias are consistent with an underlying metabolic or genetic condition. Transient and developmental movement disorders include benign neonatal sleep myoclonus, jitteriness in neonates, shuddering, and stereotypies.

Movement disorders of the mouth: a review of the common phenomenologies

Movement disorders of the mouth encompass a spectrum of hyperactive movements involving the muscles of the orofacial complex. They are rare conditions and are described in the literature primarily in case reports originating from neurologists, psychiatrists, and the dental community. The focus of this review is to provide a phenomenological description of different oral motor disorders including oromandibular dystonia, orofacial dyskinesia and orolingual tremor, and to offer management strategies for optimal treatment based on the current literature. A literature search of full text studies using PubMed/Medline and Cochrane library combined with a manual search of the reference lists was conducted until June 2021. Results from this search included meta-analyses, systematic reviews, reviews, clinical studies, case series, and case reports published by neurologists, psychiatrists, dentists and oral and maxillofacial surgeons. Data garnered from these sources were used to provide an overview of most commonly encountered movement disorders of the mouth, aiding physicians in recognizing these rare conditions and in initiating appropriate therapy.

Advances in DBS Technology and Novel Applications: Focus on Movement Disorders

PURPOSE OF REVIEW

Deep brain stimulation (DBS) is an established treatment in several movement disorders, including Parkinson's disease, dystonia, tremor, and Tourette syndrome. In this review, we will review and discuss the most recent findings including but not limited to clinical evidence.

RECENT FINDINGS

New DBS technologies include novel hardware design (electrodes, cables, implanted pulse generators) enabling new stimulation patterns and adaptive DBS which delivers potential stimulation tailored to moment-to-moment changes in the patient's condition. Better understanding of movement disorders pathophysiology and functional anatomy has been pivotal for studying the effects of DBS on the mesencephalic locomotor region, the nucleus basalis of Meynert, the substantia nigra, and the spinal cord. Eventually, neurosurgical practice has improved with more accurate target visualization or combined targeting. A rising research domain emphasizes bridging neuromodulation and neuroprotection. Recent advances in DBS therapy bring more possibilities to effectively treat people with movement disorders. Future research would focus on improving adaptive DBS, leading more clinical trials on novel targets, and exploring neuromodulation effects on neuroprotection.

[Childhood-Onset Intractable Neurological Disorders, Mainly Movement Disorders]

Some intractable neurological disorders, mainly movement disorders of childhood, have been outlined. It is recommended that healthcare transition be provided in a multidisciplinary setting to meet patient needs. The pediatrician in charge of transitional patients should take the lead in providing advice on the advantages and disadvantages of medical options, while respecting the patient's and family/guardian's right to self-determination to jointly reach a satisfactory decision. Here, we briefly described some of the issues that cause transition difficulties.

[Functional Movement Disorders That Do Not Improve after Explaining the Diagnosis: The Role of Neurologists]

In recent years, the term "functional" is starting to replace "psychogenic" when referring to a specific group of movement disorders, with an increasing emphasis being placed on the role of neurologists in the management of these disorders. These conditions are common and disabling, and sometimes difficult to diagnose. History taking and physical examination may highlight positive signs suggestive of diagnosis, which should not be based on exclusion. During examination, the distraction sign may be observed. When functional myoclonus is present, the patient's movements may vary over time. The role of a neurologist is not only to diagnose functional movement disorders, but also explain to the patient that the patient has a distinct neurological disorder and provide clinical evidence that supports the diagnosis. It is useful to share the positive signs with patients when explaining the diagnosis. In this article, I describe a patient with functional abdominal jerks to demonstrate how a diagnosis is made and how one can explain the diagnosis to the patient. Once a patient accepts and understands the diagnosis, treatment can be initiated. Collaboration with psychiatrists and physiotherapists is essential. It has been shown that cognitive behavioral therapy and physiotherapy are beneficial in ameliorating functional movements.

Deep brain stimulation for movement disorder treatment: exploring frequency-dependent efficacy in a computational network model

A large-scale computational model of the basal ganglia network and thalamus is proposed to describe movement disorders and treatment effects of deep brain stimulation (DBS). The model of this complex network considers three areas of the basal ganglia region: the subthalamic nucleus (STN) as target area of DBS, the globus pallidus, both pars externa and pars interna (GPe-GPi), and the thalamus. Parkinsonian conditions are simulated by assuming reduced dopaminergic input and corresponding pronounced inhibitory or disinhibited projections to GPe and GPi. Macroscopic quantities are derived which correlate closely to thalamic responses and hence motor programme fidelity. It can be demonstrated that depending on different levels of striatal projections to the GPe and GPi, the dynamics of these macroscopic quantities (synchronisation index, mean synaptic activity and response efficacy) switch from normal to Parkinsonian conditions. Simulating DBS of the STN affects the dynamics of the entire network, increasing the thalamic activity to levels close to normal, while differing from both normal and Parkinsonian dynamics. Using the mentioned macroscopic quantities, the model proposes optimal DBS frequency ranges above 130 Hz.

Neurocognitive and hypokinetic movement disorder with features of parkinsonism after BCMA-targeting CAR-T cell therapy

B-cell maturation antigen (BCMA) is a prominent tumor-associated target for chimeric antigen receptor (CAR)-T cell therapy in multiple myeloma (MM). Here, we describe the case of a patient with MM who was enrolled in the CARTITUDE-1 trial ( NCT03548207 ) and who developed a progressive movement disorder with features of parkinsonism approximately 3 months after ciltacabtagene autoleucel BCMA-targeted CAR-T cell infusion, associated with CAR-T cell persistence in the blood and cerebrospinal fluid, and basal ganglia lymphocytic infiltration. We show BCMA expression on neurons and astrocytes in the patient's basal ganglia. Public transcriptomic datasets further confirm BCMA RNA expression in the caudate of normal human brains, suggesting that this might be an on-target effect of anti-BCMA therapy. Given reports of three patients with grade 3 or higher parkinsonism on the phase 2 ciltacabtagene autoleucel trial and of grade 3 parkinsonism in the idecabtagene vicleucel package insert, our findings support close neurological monitoring of patients on BCMA-targeted T cell therapies.

Spectrum of Movement Disorders in two Movement Disorders Centers in the Philippines

OBJECTIVE

Presently, there are no epidemiologic data on the prevalence of movement disorders in the Philippines. We aim to describe the most common phenomenologies and movement disorders in two specialty centers in Metro Manila dedicated to movement disorders.

METHODS

We investigated the clinical spectrum and etiologies of movement disorders referred to our centers from January 2007-December 2019 using a standardized collection form.

RESULTS

A total of 1438 patients presenting with complaints relating to movement disorders were evaluated between 2007 to 2019. There were 770 (53.5%) men. The mean age was 57.1 ± 17.9 years. The most common movement disorders were parkinsonism (n=677, 47.1%), myoclonus (n=212, 14.7%) and tremor (n=208, 14.5%). The least common was restless legs syndrome (n=4, 0.3%). There were 78 (37.7% of total dystonia cases) X-linked dystonia-parkinsonism patients referred to our clinic. Majority of the botulinum toxin injections were for hemifacial spasms (n=206). A small number of patients (n=41) were also seen at the center for deep brain stimulation programming.

CONCLUSION

The most common movement disorders managed were parkinsonism, myoclonus and tremor. The most common diagnoses were Parkinson's disease, hemifacial spasm and essential tremor. This study highlights the spectrum of movement disorders encountered in two specialty clinics in two Philippine tertiary hospitals. Given these varied cases, there is also a need for more movement specialists and centers dedicated to movement disorders to manage these cases.

The Clinical Value of Patient Home Videos in Movement Disorders

Background

Numerous studies have shown the value of patient home video recordings within the field of epilepsy. Despite the growing influence of mobile technology and telemedicine, there is a paucity of studies examining the role of home videos in the diagnosis of movement disorders.

Objective

To characterize the clinical value of patient home videos in a movement disorders practice.

Methods

We performed a retrospective review from our video database over the past 10 years and identified 20 encounters where an in-person, clinic evaluation and studio video were supplemented by a home video. We reviewed these encounters to determine if the home video added additional value to the clinic video. The home videos were screened by 3 movement disorders attendings and 3 movement disorders fellows to assess for quality and to determine whether or not the patient phenomenology could accurately be identified.

Results

Of the 20 videos identified, 10 (50%) were determined to be of additional clinical value. In 62.4% of evaluations movement disorders attendings and fellows were able to identify phenomenology from the home videos consistent with the final diagnosis. Videos rated as "poor" quality had significantly lower odds of leading to a correct phenomenology (odd ratio: 0.07, 95% confidence interval [0.01-0.72]) than those rated as "excellent" quality.

Conclusions

Patients should be encouraged to produce good quality home videos, particularly in paroxysmal or fluctuating movement disorders, as they may add value to the eventual diagnosis and management.

Effect of Acupuncture on Neuroplasticity of Stroke Patients with Motor Dysfunction: A Meta-Analysis of fMRI Studies

Objective

To analyze the pattern of intrinsic brain activity variability that is altered by acupuncture compared with conventional treatment in stroke patients with motor dysfunction, thus providing the mechanism of stroke treatment by acupuncture.

Methods

Chinese and English articles published up to May 2020 were searched in the PubMed, Web of Science, EMBASE, and Cochrane Library databases, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang Database. We only included randomized controlled trials (RCTs) using resting-state fMRI to observe the effect of acupuncture on stroke patients with motor dysfunction. R software was used to analyze the continuous variables, and Seed-based d Mapping with Permutation of Subject Images (SDM-PSI) was used to perform an analysis of fMRI data. Findings. A total of 7 studies comprising 143 patients in the treatment group and 138 in the control group were included in the meta-analysis. The results suggest that acupuncture treatment helps the healing process of motor dysfunction in stroke patients and exhibits hyperactivation in the bilateral basal ganglia and insula and hypoactivation in motor-related areas (especially bilateral BA6 and left BA4).

Conclusion

Acupuncture plays a role in promoting neuroplasticity in subcortical regions that are commonly affected by stroke and cortical motor areas that may compensate for motor deficits, which may provide a possible mechanism underlying the therapeutic effect of acupuncture.

Extracellular vesicles derived from bone marrow mesenchymal stem cells enhance myelin maintenance after cortical injury in aged rhesus monkeys

Cortical injury, such as stroke, causes neurotoxic cascades that lead to rapid death and/or damage to neurons and glia. Axonal and myelin damage in particular, are critical factors that lead to neuronal dysfunction and impair recovery of function after injury. These factors can be exacerbated in the aged brain where white matter damage is prevalent. Therapies that can ameliorate myelin damage and promote repair by targeting oligodendroglia, the cells that produce and maintain myelin, may facilitate recovery after injury, especially in the aged brain where these processes are already compromised. We previously reported that a novel therapeutic, Mesenchymal Stem Cell derived extracellular vesicles (MSC-EVs), administered intravenously at both 24 h and 14 days after cortical injury, reduced microgliosis (Go et al. 2019), reduced neuronal pathology (Medalla et al. 2020), and improved motor recovery (Moore et al. 2019) in aged female rhesus monkeys. Here, we evaluated the effect of MSC-EV treatment on changes in oligodendrocyte maturation and associated myelin markers in the sublesional white matter using immunohistochemistry, confocal microscopy, stereology, qRT-PCR, and ELISA. Compared to vehicle control monkeys, EV-treated monkeys showed a reduction in the density of damaged oligodendrocytes. Further, EV-treatment was associated with enhanced myelin maintenance, evidenced by upregulation of myelin-related genes and increases in actively myelinating oligodendrocytes in sublesional white matter. These changes in myelination correlate with the rate of motor recovery, suggesting that improved myelin maintenance facilitates this recovery. Overall, our results suggest that EVs act on oligodendrocytes to support myelination and improves functional recovery after injury in the aged brain. SIGNIFICANCE: We previously reported that EVs facilitate recovery of function after cortical injury in the aged monkey brain, while also reducing neuronal pathology (Medalla et al. 2020) and microgliosis (Go et al. 2019). However, the effect of injury and EVs on oligodendrocytes and myelination has not been characterized in the primate brain (Dewar et al. 1999; Sozmen et al. 2012; Zhang et al. 2013). In the present study, we assessed changes in myelination after cortical injury in aged monkeys. Our results show, for the first time, that MSC-EVs support recovery of function after cortical injury by enhancing myelin maintenance in the aged primate brain.

Palliative Care in Movement Disorders: an Evolving Field

PURPOSE OF REVIEW

This review summarizes the current state of evidence for palliative care (PC) in movement disorders, describes the application of PC to clinical practice, and suggests future research directions.

RECENT FINDINGS

PC needs are common in persons living with movement disorders and their families from the time of diagnosis through end-of-life and contribute to quality of life. Early advance care planning is preferred by patients, impacts outcomes and is promoted by PC frameworks. Systematic assessment of non-motor symptoms, psychosocial needs and spiritual/existential distress may address gaps in current models of care. Several complementary and emerging models of PC may be utilized to meet the needs of this population. A PC approach may identify and improve important patient and caregiver-centered outcomes. As a relatively new application of PC, there is a need for research to adapt, develop and implement approaches to meet the unique needs of this population.

Cross-frequency coupling between gamma oscillations and deep brain stimulation frequency in Parkinson's disease

The disruption of pathologically enhanced beta oscillations is considered one of the key mechanisms mediating the clinical effects of deep brain stimulation on motor symptoms in Parkinson's disease. However, a specific modulation of other distinct physiological or pathological oscillatory activities could also play an important role in symptom control and motor function recovery during deep brain stimulation. Finely tuned gamma oscillations have been suggested to be prokinetic in nature, facilitating the preferential processing of physiological neural activity. In this study, we postulate that clinically effective high-frequency stimulation of the subthalamic nucleus imposes cross-frequency interactions with gamma oscillations in a cortico-subcortical network of interconnected regions and normalizes the balance between beta and gamma oscillations. To this end we acquired resting state high-density (256 channels) EEG from 31 patients with Parkinson's disease who underwent deep brain stimulation to compare spectral power and power-to-power cross-frequency coupling using a beamformer algorithm for coherent sources. To show that modulations exclusively relate to stimulation frequencies that alleviate motor symptoms, two clinically ineffective frequencies were tested as control conditions. We observed a robust reduction of beta and increase of gamma power, attested in the regions of a cortical (motor cortex, supplementary motor area, premotor cortex) and subcortical network (subthalamic nucleus and cerebellum). Additionally, we found a clear cross-frequency coupling of narrowband gamma frequencies to the stimulation frequency in all of these nodes, which negatively correlated with motor impairment. No such dynamics were revealed within the control posterior parietal cortex region. Furthermore, deep brain stimulation at clinically ineffective frequencies did not alter the source power spectra or cross-frequency coupling in any region. These findings demonstrate that clinically effective deep brain stimulation of the subthalamic nucleus differentially modifies different oscillatory activities in a widespread network of cortical and subcortical regions. Particularly the cross-frequency interactions between finely tuned gamma oscillations and the stimulation frequency may suggest an entrainment mechanism that could promote dynamic neural processing underlying motor symptom alleviation.

Forced exercise activates the NrF2 pathway in the striatum and ameliorates motor and behavioral manifestations of Parkinson's disease in rotenone-treated rats

BACKGROUND

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by progressive loss of nigrostriatal dopaminergic neurons leading to dopamine depletion and problems of movement, emotions, and cognition. While the pathogenesis of PD is not clear, damage of dopaminergic neurons by oxygen-derived free radicals is considered an important contributing mechanism. This study aimed to evaluate the role of treadmill exercise in male Wister rats as a single treatment and as an aid-therapy with L-dopa for rotenone-induced PD. To study the role of the Nrf2- ARE pathway as a mechanism involved in exercise-associated improvement in rotenone-induced PD in rats.

METHOD

Animals were divided into 5 groups, (Control, rotenone, rotenone\exercise, rotenone\L-dopa, and rotenone\exercise\L-dopa (combination)groups). After the PD induction, rats in the rotenone\exercise and combination groups were daily treadmill exercised for 4 weeks.

RESULTS

Treadmill exercise significantly improved behavioral and motor aspects of rotenone-induced PD. When treadmill exercise was introduced as a single intervention, it amended most behavioral aspects of PD, gait fully corrected, short-term memory, and motor coordination. Where L-dopa corrected locomotor activity and motor coordination but failed to improve short-term memory and only partially corrected the gait of rotenone-treated rats. When treadmill exercise was combined with L-dopa, all features of PD were corrected. It was found that exercise upregulated some of its associative genes to Nrf2 pathways such as TFAM, Nrf2 and NQO.1 mRNA expression.

CONCLUSION

This study suggests that forced exercise improved parkinsonian like features by activating the Nrf2 pathway.

Implementation of Mobile Health Technologies in Clinical Trials of Movement Disorders: Underutilized Potential

Mobile health technologies (mHealth) are patient-worn or portable devices aimed at increasing the granularity and relevance of clinical measurements. The implementation of mHealth has the potential to decrease sample size, duration, and cost of clinical trials. We performed a review of the ClinicalTrials.gov database using a standardized approach to identify adoption in and usefulness of mHealth in movement disorders interventional clinical trials. Trial phase, geographical area, availability of data captured, constructs of interest, and outcome priority were collected. Eligible trials underwent quality appraisal using an ad hoc 5-point checklist to assess mHealth feasibility, acceptability, correlation with patient-centered outcome measures, and clinical meaningfulness. A total of 29% (n = 54/184) registered trials were using mHealth, mainly in Parkinson's disease and essential tremor (59.3% and 27.8%). In most cases, mHealth were used in phase 2 trials (83.3%) as secondary outcome measures (59.3%). Only five phase 3 trials, representing 9.3% of the total, used mHealth (1 as primary outcome measure, 3 as secondary, and 1 as tertiary). Only 3.7% (n = 2/54) of all trials used mHealth for measuring both motor and non-motor symptoms, and 23.1% (n = 12/52) used mHealth for unsupervised, ecologic outcomes. Our findings suggest that mHealth remain underutilized and largely relegated to phase 2 trials for secondary or tertiary outcome measures. Efforts toward greater alignment of mHealth with patient-centered outcomes and development of a universal, common-language platform to synchronize data from one or more devices will assist future efforts toward the integration of mHealth into clinical trials.

Treatment of Disorders of Tone and Other Considerations in Pediatric Movement Disorders

Pediatric movement disorders (PMDs) consist of a heterogeneous group of signs and symptoms caused by numerous neurological diseases. Different neurological disorders in children also share overlapping movement disorders making a diagnosis of the underlying cause of the movement disorder challenging. The similarity of the symptoms across multiple disease types suggests that there may be a final common motor pathway causing the overlapping movement disorders. There are numerous disorders in children associated with disturbances in tone and involuntary movements. This chapter will focus primarily on those disorders that involve abnormalities of tone and other important considerations of pediatric movement disorders. This chapter will address rating scales and goals for treatment and will include a review of symptomatic treatment and, where possible, the treatment of the underlying disease processes. The chapter will review representative disorders, including an inborn error of metabolism, an autoimmune disorder, and a group of neurodegenerative disorders. These examples demonstrate how the disorder's underlying pathophysiology results in a specific approach to the underlying disease and the associated conditions of tone and involuntary movements. Finally, the multiple treatment options for cerebral palsy and considerations of cerebral palsy mimics will be discussed.

4-year-old girl • limited movement & diffuse pain in both arms • pronated hands • Dx?

► Limited movement in both arms ► Diffuse pain in elbows, forearms, and upper arms ► Pronated hands.

Image analysis of the intracranial lead bending phenomenon during deep brain stimulation

Background

An accurate and precise surgical procedure is crucial for patient safety and treatment efficacy of deep brain stimulation (DBS).

Objectives

To investigate the characteristics of intracranial lead bending phenomenon after DBS, and to suggest the methods to avoid bending-related complications.

Methods

A retrospective review of brain computed tomography scans after DBS was performed. Using 3-dimensional reconstruction, the maximal distance between the planned trajectory and actual lead location was measured. When the distance exceeded the lead body diameter, the lead was considered bent. The distance between the bending point and planned trajectory, and the relative direction between the bending point and lead securing site were analyzed. Changes over time in the range of lead bending and depth were analyzed when possible.

Results

A total of 190 implanted leads in 102 patients were analyzed; 104 leads (54.7%) were bent. The average deviation of bent leads was 2.3 mm (range, 1.3–7.1 mm). Thirty-five (18.4%) and seven leads (3.7%) had deviations exceeding twice and three times the lead body diameter, respectively. Angles between the deviation point and securing site at the skull ranged from 135–180° in 83 leads (53.2%), 45–135° in 58 (37.2%), and 0–45° in 15 (9.6%). Among 17 leads that were initially bent, 16 had less deviation compared to baseline. The lead depth increased in 35 (92.1%) of 38 leads by 1.2 mm (range, 0.1–4.7 mm).

Conclusion

The extent of lead bending should be considered during the planning and procedural phases of intracranial lead implantation for DBS.

[Movement disorders in children]

Movement disorders in children. The phenomenological spectrum of pediatric movement disorders is wide and correspond to a large variety of causes. It comprises fixed transient, and progressive disorders. Relative frequencies differ from those observed in adult neurology. Neurodevelopmental motor disorders such as tics, stereotypies and dystonia are more prevalent than parkinsonism. Proper characterization of the movement disorder is the starting point to the diagnosis. A particular attention should be paid to detailed clinical history, associated features, psychomotor development, tempo of appearance and time course of symptoms, precipitating or alleviating factors, and interference with voluntary movements. Evaluation of the functional impairment is critical to guide the clinical care of the children. Focus on potentially treatable disorders is essential. Here, we propose some practical guidance for diagnosis and treatment of movement disorders in children.

Parkinson's Disease in the Middle East, North Africa, and South Asia: Consensus from the International Parkinson and Movement Disorder Society Task Force for the Middle East

BACKGROUND

Understanding the regional needs and available healthcare resources to treat Parkinson's disease (PD) is essential to plan appropriate future priorities. The International Parkinson and Movement Disorder Society (MDS) Task Force for the Middle East was established to raise awareness and promote education across the region on PD and other movement disorders. Broadly, the task force encompasses the countries of the Middle East but has included North Africa and South Asia as well (MENASA).

OBJECTIVE

To create a list of needs and priorities in the advancement of PD in MENASA countries based on consensuses generated by the MDS task force for the Middle East.

METHODS

A Strengths Weaknesses-Opportunities-Threats (SWOT) analysis was conducted by the task force members to generate consensus about PD care this region.

RESULTS

Eight overarching principles emerged for the consensus statement on current needs: more movement disorders specialists, multidisciplinary care, accurate epidemiologic data, educational programs, availability of drugs, and availability of more advanced therapy, enhanced health care resources and infrastructure, and greater levels of awareness within the general population and among health care professionals.

CONCLUSION

This pilot study sheds light on unmet needs for providing care to people with PD in the MENASA region. These data offer directions on priorities to increase awareness of PD, to develop better infrastructure for research and management of PD, to foster healthcare policy discussions for PD and to provide educational opportunities within these countries.

Movement disorders in pregnancy

Movement disorders in women during pregnancy are uncommon. Therefore, high quality studies are limited, and guidelines are lacking for the treatment of movement disorders in pregnancy, thus posing a significant therapeutic challenge for the treating physicians. In this chapter, we discuss movement disorders that arise during pregnancy and the preexisting movement disorders during pregnancy. Common conditions encountered in pregnancy include but are not limited to restless legs syndrome, chorea gravidarum, Parkinson disease, essential tremor, and Huntington disease as well as more rare movement disorders (Wilson's disease, dystonia, etc.). This chapter summarizes the published literature on movement disorders and pharmacologic and surgical considerations for neurologists and physicians in other specialties caring for patients who are pregnant or considering pregnancy.

Localising movement disorders in childhood

The diagnosis and management of movement disorders in children can be improved by understanding the pathways, neurons, ion channels, and receptors involved in motor learning and control. In this Review, we use a localisation approach to examine the anatomy, physiology, and circuitry of the basal ganglia and highlight the mechanisms that underlie some of the major movement disorders in children. We review the connections between the basal ganglia and the thalamus and cortex, address the basic clinical definitions of movement disorders, and then place diseases within an anatomical or physiological framework that highlights basal ganglia function. We discuss how new pharmacological, behavioural, and electrophysiological approaches might benefit children with movement disorders by modifying synaptic function. A better understanding of the mechanisms underlying movement disorders allows improved diagnostic and treatment decisions.

Paraneoplastic movement disorders: phenomenology, diagnosis, and treatment

Paraneoplastic syndromes include, by definition, any symptomatic and non-metastatic condition associated with a neoplasm. Paraneoplastic movement disorders are a heterogeneous group of syndromes encompassing both hyperkinetic and hypokinetic conditions, characterized by acute/sub-acute onset, rapidly progressive evolution, and multifocal localizations with several overlapping features. These movement disorders are immune-mediated, as shown by the rapid onset and by the presence of antineuronal antibodies in biological samples of patients, fundamental for the diagnosis. Antineuronal antibodies could be targeted against intracellular or neuronal surface antigens. Paraneoplastic movement disorders associated with anti-neuronal surface antigens antibodies respond more frequently to immunotherapy. The underlying tumors may be different, according to the clinical presentation, age, and gender of patients. Our search considered articles involving human subjects indexed in PubMed. Abstracts were independently reviewed for eligibility criteria by one author and validated by at least one additional author. In this review, we sought to critically reappraise the clinical features and the pathophysiological mechanisms of paraneoplastic movement disorders, focusing on diagnostic and therapeutic strategies. Our main aim is to make clinicians aware of paraneoplastic movement disorders, and to provide assistance in the early diagnosis and management of these rare but life-threatening conditions.

Emerging technologies for improved deep brain stimulation

Deep brain stimulation (DBS) is an effective treatment for common movement disorders and has been used to modulate neural activity through delivery of electrical stimulation to key brain structures. The long-term efficacy of stimulation in treating disorders, such as Parkinson's disease and essential tremor, has encouraged its application to a wide range of neurological and psychiatric conditions. Nevertheless, adoption of DBS remains limited, even in Parkinson's disease. Recent failed clinical trials of DBS in major depression, and modest treatment outcomes in dementia and epilepsy, are spurring further development. These improvements focus on interaction with disease circuits through complementary, spatially and temporally specific approaches. Spatial specificity is promoted by the use of segmented electrodes and field steering, and temporal specificity involves the delivery of patterned stimulation, mostly controlled through disease-related feedback. Underpinning these developments are new insights into brain structure-function relationships and aberrant circuit dynamics, including new methods with which to assess and refine the clinical effects of stimulation.

[Deep brain stimulation for movement disorders]

Deep brain stimulation (DBS) is a treatment which uses high-frequency electric stimulation to suppress pathological brain activity. DBS has been applied for over 30 years now, particularly in patients with severe movement disorders, such as Parkinson's disease, dystonia and tremor. Although there is clearly scientific evidence for the effectiveness of DBS in these three movement disorders, the effect size of the treatment remains limited. Furthermore, DBS is not curative and can only be applied in a select subset of patients. In this article, we discuss the key indications and contraindications for DBS, and the outcomes achieved when it is applied in the aforementioned movement disorders. We discuss the most notable controversies and new developments in the field of deep brain stimulation, in order to offer referrers and fellow healthcare professionals an accessible introduction to this mode of therapy.

Movement Disorders in Children

PURPOSE OF REVIEW

This article provides an overview of the clinical features and disorders associated with movement disorders in childhood. This article discusses movement disorder phenomena and their clinical presentation in infants and children and presents a diagnostic approach to suspected genetic disorders with a focus on treatable conditions.

RECENT FINDINGS

Technologic advances in molecular genetic testing over the past decade continue to lead to the discovery of new diseases. This article discusses the clinical presentation and early experience with treatment for several recently described genetic forms of infantile-onset and childhood-onset dystonia and chorea.

SUMMARY

The clinical spectrum of pediatric movement disorders is broad and heterogeneous, ranging from acute or transient self-limited conditions to conditions that cause profound lifelong motor disability. Most movement disorders in childhood are chronic, and the large number of rare, genetic conditions associated with pediatric movement disorders can pose a significant diagnostic challenge. Recognition of distinctive diagnostic clues in the history and examination can facilitate the diagnosis of potentially treatable disorders.

Patient-Specific Simulations of Deep Brain Stimulation Electric Field with Aid of In-house Software ELMA

Deep brain stimulation (DBS) is an established technique for reduction of symptoms in movement disorders. Finite element method (FEM) simulations of the electric field magnitude (EF) are useful for estimating the affected tissue around the DBS lead and this can help optimize the therapy. This paper describes how patient-specific FEM models can be set up with the aid of the Matlab-based in-house software tool ELMA. Electrode placement is determined from two coordinates in postoperative medical imaging and electric conductivity is assigned from preoperative magnetic resonance imaging (MRI) and patient-specific DBS data. Simulations are performed using the equation for steady currents in Comsol Multiphysics (CM). The simulated EF is superimposed on the preoperative MRI for evaluation of affected structures. The method is demonstrated with patient-specific simulations in the zona incerta and a globus pallidus example containing cysts with higher conductive which causes considerable distortion of the EF. The improved software modules and precise lead positioning simplifies and reduces the time for DBS EF modelling and simulation.