Network localization of pediatric lesion-induced dystonia.

Objective: Dystonia is a movement disorder defined by involuntary muscle contractions leading to abnormal postures or twisting and repetitive movements. Classically dystonia has been thought of as a disorder of the basal ganglia, but newer results in idiopathic dystonia and lesion-induced dystonia in adults point to broader motor network dysfunction spanning the basal ganglia, cerebellum, premotor cortex, sensorimotor, and frontoparietal regions. It is unclear whether a similar network is shared between different etiologies of pediatric lesion-induced dystonia. Methods: Three cohorts of pediatric patients with lesion-induced dystonia were identified. The lesion etiologies included hypoxia, kernicterus, and stroke versus comparison subjects with acquired lesions not associated with dystonia. Multivariate lesion-symptom mapping and lesion network mapping were used to evaluate the anatomy and networks associated with dystonia. Results: Multivariate lesion-symptom mapping showed that lesions of the putamen (stroke: r = 0.50, p <0.01; hypoxia, r = 0.64, p <0.001) and globus pallidus (kernicterus, r = 0.61, p <0.01) were associated with dystonia. Lesion network mapping using normative connectome data from healthy children demonstrated that these regional findings occurred within a common brain-wide network that involves the basal ganglia, anterior and medial cerebellum, and cortical regions that overlap the cingulo-opercular and somato-cognitive-action networks. Interpretation: We interpret these findings as novel evidence for a unified dystonia brain network that involves the somato-cognitive-action network, which is involved in higher order coordination of movement. Elucidation of this network gives insight into the functional origins of dystonia and provides novel targets to investigate for therapeutic intervention.

Physician Approaches to the Pharmacologic Treatment of Dystonia in Cerebral Palsy.

Objective: To determine how physicians approach pharmacologic dystonia treatment in people with CP and assess physician readiness to participate in a randomized trial comparing existing pharmacologic dystonia treatments. Methods: We administered a REDCap survey to physician members of the American Academy of Cerebral Palsy and Developmental Medicine and of the Child Neurology Society to assess which pharmacologic agents they use to treat dystonia in CP and their preferred indications and dosing. Results: Of 479 physicians surveyed, 240 (50%) responded. Respondents treated functionally limiting (95%) and generalized (57%) dystonia and most commonly used six medications: baclofen (95%), trihexyphenidyl (79%), gabapentin (67%), carbidopa/levodopa (55%), clonazepam (55%), and diazepam (54%). Baclofen was preferred in people with co-existing spasticity (81%), gabapentin was preferred in people with co-existing pain (49%), and trihexyphenidyl was avoided in people with constipation (34%) or urinary retention (42%). Preferred dosing regimens followed published regimens for dystonia, when available, but otherwise followed published regimens for other CP symptoms (spasticity and seizures). Baclofen was preferred by 64% of respondents as first line treatment, but there was no clear consensus on second or third-line medications. Most respondents (51%) were comfortable randomizing their patients to receive any of the six most commonly used medications used to treat dystonia in CP. Conclusions: This study summarizes current indications and dosing for the six most commonly used medications to treat dystonia in CP as per treating physicians in the US and Canada and also demonstrates physician support for a randomized trial comparing the effectiveness of these treatments.

Predictive and diagnostic measures for kernicterus spectrum disorder: a prospective cohort study.

BACKGROUND: Kernicterus spectrum disorder (KSD) resulting from neonatal hyperbilirubinemia remains a common cause of cerebral palsy worldwide. This 12-month prospective cohort study followed neonates with hyperbilirubinemia to determine which clinical measures best predict KSD. METHODS: The study enrolled neonates ≥35 weeks gestation with total serum bilirubin (TSB) ≥ 20 mg/dl admitted to Aminu Kano Hospital, Nigeria. Clinical measures included brain MRI, TSB, modified bilirubin-induced neurologic dysfunction (BIND-M), Barry-Albright Dystonia scale (BAD), auditory brainstem response (ABR), and the modified KSD toolkit. MRI signal alteration of the globus pallidus was scored using the Hyperbilirubinemia Imaging Rating Tool (HIRT). RESULTS: Of 25 neonates enrolled, 13/25 completed 12-month follow-up and six developed KSD. Neonatal BIND-M ≥ 3 was 100% sensitive and 83% specific for KSD. Neonatal ABR was 83% specific and sensitive for KSD. Neonatal HIRT score of 2 was 67% sensitive and 75% specific for KSD; this increased to 100% specificity and sensitivity at 12 months. BAD ≥ 2 was 100% specific for KSD at 3-12 months, with 50-100% sensitivity. CONCLUSIONS: Neonatal MRIs do not reliably predict KSD. BIND-M is an excellent screening tool for KSD, while the BAD or HIRT score at 3 or 12 months can confirm KSD, allowing for early diagnosis and intervention. IMPACT: The first prospective study of children with acute bilirubin encephalopathy evaluating brain MRI findings over the first year of life. Neonatal MRI is not a reliable predictor of kernicterus spectrum disorders (KSD). Brain MRI at 3 or 12 months can confirm KSD. The modified BIND scale obtained at admission for neonatal hyperbilirubinemia is a valuable screening tool to assess risk for developing KSD. The Barry Albright Dystonia scale and brain MRI can be used to establish a diagnosis of KSD in at-risk infants as early as 3 months.

SIGnature Libraries: A roadmap for the formation of special interest group libraries.

Objective: "SIGnature Libraries" channel the dynamism of academic society-based special interest groups (SIG) to systematically identify and provide user-oriented access to essential literature for a subspecialty field in a manner that keeps pace with the field's continuing evolution. The libraries include literature beyond clinical trial data to encompass historical context, diagnostic conceptualization, and community organization materials to foster a holistic understanding of how neurologic conditions affect individuals, their community, and their lived experience. Methods: Utilizing a modified-Delphi approach, Child Neurology Society's Cerebral Palsy (CP) SIG (n = 75) administered two rounds of literature submissions and ratings. A final review by an 11-member international advisory group determined threshold ratings for resource inclusion and the library's final structure. Results: Seventy-nine articles were submitted for the first Delphi round and 22 articles for the second Delphi round. Survey response rates among SIG members were 29/75 for the first round and 24/75 for the second round. The advisory board added additional articles in the final review process in view of the overall project goal. A total of 60 articles were included in the final library, and articles were divided into seven sections and stratified by rating scores. A process for ongoing revisions of the library was determined. The library will be published on the Child Neurology Society website and made publicly accessible. Conclusions: The CP SIGnature Library offers learners an unprecedented resource that provides equitable access to latest consensus guidelines, existing seminal datasets, up-to-date review articles, and other patient care tools. A distinctive feature of the library is its intentional large scope and depth, presented in a stratified fashion relative to the consensus-determined importance of each article. Learners can efficiently navigate the library based on individual interests and goals, and the library can be used as core curriculum for CP education.

Chronic striatal cholinergic interneuron excitation induces clinically-relevant dystonic behavior in mice.

Dystonia is common, debilitating, often medically refractory, and difficult to diagnose. The gold standard for both clinical and mouse model dystonia evaluation is subjective assessment, ideally by expert consensus. However, this subjectivity makes translational quantification of clinically-relevant dystonia metrics across species nearly impossible. Many mouse models of genetic dystonias display abnormal striatal cholinergic interneuron excitation, but few display subjectively dystonic features. Therefore, whether striatal cholinergic interneuron pathology causes dystonia remains unknown. To address these critical limitations, we first demonstrate that objectively quantifiable leg adduction variability correlates with leg dystonia severity in people. We then show that chemogenetic excitation of striatal cholinergic interneurons in mice causes comparable leg adduction variability in mice. This clinically-relevant dystonic behavior in mice does not occur with acute excitation, but rather develops after 14 days of ongoing striatal cholinergic interneuron excitation. This requirement for prolonged excitation recapitulates the clinically observed phenomena of a delay between an inciting brain injury and subsequent dystonia manifestation and demonstrates a causative link between chronic striatal cholinergic interneuron excitation and clinically-relevant dystonic behavior in mice. Therefore, these results support targeting striatal ChIs for dystonia drug development and suggests early treatment in the window following injury but prior to dystonia onset. One Sentence Summary: Chronic excitation of dorsal striatal cholinergic interneuron causes clinically-relevant dystonic phenotypes in mice.

Identifying Effective Treatments for Dystonia in Patients With Cerebral Palsy: A Precision Therapeutics Approach.

Recent focus on improving the recognition of dystonia in cerebral palsy (DCP) has highlighted the need for more effective treatments. Evidence supports improved functional outcomes with early interventions for patients with cerebral palsy, but it is not known which interventions are most effective for DCP. Current pharmacologic recommendations for DCP are based largely on anecdotal evidence, with medications demonstrating minimal to moderate improvements in dystonia and variable efficacy between patients. Patients, families, and clinicians have identified the need for new and improved treatments in DCP, naming this as the top research theme in a recent Neurology® publication. Precision therapeutics focuses on providing early effective interventions that are individualized to every patient and can guide research priorities to improve treatments for DCP. This commentary outlines current obstacles to improving treatment of DCP and addresses how precision therapeutics can address each of these obstacles through 4 key components: (1) identification of predictive biomarkers to select patients likely to develop DCP in the future and for whom early intervention may be appropriate to delay or prevent full manifestation of dystonia, (2) stratification of patients with DCP into subgroups according to shared features (clinical, functional, biochemical, etc) to provide a targeted intervention based on those shared features, (3) administration of an individualized dose of an effective intervention to ensure adequate concentrations of the therapeutic entity at the site of action, and (4) monitoring of objective biomarkers of response to intervention. With implementation of each of these components of precision therapeutics, new and more effective treatments for every person with DCP can be realized.

The Role of Child Neurologists in the Management of Motor Disability in Cerebral Palsy: Establishing the Path Forward.

BACKGROUND: Cerebral palsy (CP) is the most common motor disability of childhood, and yet the role of child neurologists and neurodevelopmentalists (CN/NDDs) in the management of children with CP is unclear. Although previous surveys showed that CN/NDDs believe they are uniquely expert in CP motor phenotyping and should be involved in CP management, others have demonstrated that training in CP management among CN/NDD residency programs is inadequate. METHODS: In this article, we surveyed a group of CN/NDDs at the Child Neurology Society Cerebral Palsy Special Interest Group meeting on January 27, 2022. Questions addressed provider comfort with CP tone management including motor phenotyping, pharmacologic and surgical management, barriers and solutions to improving practice, and the use of systems-based care. RESULTS: Responses from 42 participants demonstrated that CN/NDDs lack experience with CP tone management, with 48% and 58% of respondents reporting little to no experience in pharmacologic or surgical management, respectively. Primary barriers identified to improving comfort with CP tone management included lack of knowledge and ineffective treatment options, while most solutions centered on improving collaborations between CN/NDDs and other specialties. Only 50% of respondents reported currently using systems-based care in the management of patients with CP. CONCLUSIONS: An interdisciplinary, systems-based care model would allow for collaboration and knowledge sharing between involved specialties and provide high-value goal-directed care to maximize the functional outcomes for every individual with CP.

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.

Genomic answers for children: Dynamic analyses of >1000 pediatric rare disease genomes.

PURPOSE: This study aimed to provide comprehensive diagnostic and candidate analyses in a pediatric rare disease cohort through the Genomic Answers for Kids program. METHODS: Extensive analyses of 960 families with suspected genetic disorders included short-read exome sequencing and short-read genome sequencing (srGS); PacBio HiFi long-read genome sequencing (HiFi-GS); variant calling for single nucleotide variants (SNV), structural variant (SV), and repeat variants; and machine-learning variant prioritization. Structured phenotypes, prioritized variants, and pedigrees were stored in PhenoTips database, with data sharing through controlled access the database of Genotypes and Phenotypes. RESULTS: Diagnostic rates ranged from 11% in patients with prior negative genetic testing to 34.5% in naive patients. Incorporating SVs from genome sequencing added up to 13% of new diagnoses in previously unsolved cases. HiFi-GS yielded increased discovery rate with >4-fold more rare coding SVs compared with srGS. Variants and genes of unknown significance remain the most common finding (58% of nondiagnostic cases). CONCLUSION: Computational prioritization is efficient for diagnostic SNVs. Thorough identification of non-SNVs remains challenging and is partly mitigated using HiFi-GS sequencing. Importantly, community research is supported by sharing real-time data to accelerate gene validation and by providing HiFi variant (SNV/SV) resources from >1000 human alleles to facilitate implementation of new sequencing platforms for rare disease diagnoses.

Cerebral Palsy in Child Neurology and Neurodevelopmental Disabilities Training: An Unmet Need.

BACKGROUND: Cerebral palsy (CP) is the most common cause of childhood motor disability. However, there is limited guidance on training of child neurologists and neurodevelopmental disability specialists in the care of individuals with cerebral palsy. We sought to determine training program directors' impressions of the importance and adequacy of training in the diagnosis and management of cerebral palsy. METHODS: In this cross-sectional study, all 82 child neurology and neurodevelopmental disability program directors were asked to complete a survey querying program characteristics, aspects of training in cerebral palsy, importance of cerebral palsy training, and perceived competence at graduation in cerebral palsy care. RESULTS: There were 35 responses (43% response rate). Nearly all program directors (91%) reported "learning to diagnose cerebral palsy" as very important, and most (71%) felt that "learning to manage cerebral palsy" was very important. Although most program directors reported trainees to be very or extremely competent in cerebral palsy diagnosis (77%), only 43% of program directors felt that trainees were very or extremely competent in cerebral palsy management. Time spent with cerebral palsy faculty was associated with higher reported competence in cerebral palsy diagnosis (P = .03) and management (P < .01). The presence of a cerebral palsy clinic was associated with higher reported competence in cerebral palsy management (P = .03). CONCLUSIONS: Child neurology and neurodevelopmental disability program directors reported that training in cerebral palsy is important for residents; however, a significant proportion felt that residents were not very well prepared to manage cerebral palsy. The development of cerebral palsy curricula and exposure to cerebral palsy clinics may improve training, translating to better care of individuals with cerebral palsy.

Missed Opportunities and the Impact of the Pandemic.

CASE: Benjamin is a 9-month-old, former 36-week gestation infant who presented to the high-risk infant follow-up clinic with parental concern for developmental regression. His mother reported that Benjamin seemed to be developing typically, but over the past 2 months, he has lost the ability to visually track objects, is not as engaged with her as he once was, and now only rarely makes babbling sounds. His mother also reported episodes of intermittent "bursts" of stiffening of his extremities and brief staring spells. Benjamin's mother described him as a "good, quiet baby." She commented that he used to laugh and cry more frequently but has recently been "very peaceful and calm." Benjamin's mother recently relayed her concerns for developmental regression to his pediatrician during an audio-only telehealth visit. Benjamin was referred to a pediatric neurologist, and the consultation visit is pending.His mother is a 28-year-old single parent whose pregnancy was complicated by pre-eclampsia, gestational diabetes, and anxiety. Benjamin required admission to the neonatal intensive care unit because of initial feeding difficulties. After 1 week, Benjamin was discharged to home and was referred for early intervention services. Owing to the pandemic, there were delays with initiating intervention, but bimonthly virtual interaction with a representative from the infant development program was eventually provided.Benjamin's mother expressed significant concerns regarding the potential of exposing him to a pandemic-related illness because of bringing her son to in-person medical visits. In fact, because of her concerns, she attended only virtual well-child pediatric visits over the past 6 months. A thorough social history revealed that she is a former dance studio instructor. The studio closed and she lost her primary source of income because of the pandemic. As a result, she decided to not send Benjamin to child care and maintained isolation from extended family members.On physical examination, pertinent findings included poor truncal tone, lack of orientation toward sounds, and limited eye contact. The Bayley Scales of Infant and Toddler Development-Third Edition (Bayley-III) was administered, and the results indicated severe delays across all developmental areas, consistent with a diagnosis of global developmental delay.Benjamin's clinical presentation to the HRIF clinic and a history of developmental regression and intermittent body movements raised concerns for infantile spasms. He was transferred to the emergency department for evaluation and consideration for admission to the neurology service. An electroencephalogram confirmed epileptiform abnormalities consistent with infantile spasms, and he was immediately started on treatment.Impacts of the pandemic on the medical care of vulnerable/at-risk pediatric patients have included delayed receipt of early intervention services, parental fear regarding potential exposure to pandemic-related illness while seeking preventative care, increased use of virtual visit platforms for medical care and developmental intervention services, etc. What factors should be considered when providing support for these vulnerable/at-risk patients?

Kernicterus Spectrum Disorders Diagnostic Toolkit: validation using retrospective chart review.

BACKGROUND: Kernicterus Spectrum Disorders (KSDs) result from hyperbilirubinemia-induced brain injury. We developed a Toolkit (KSD-TK) to predict the likelihood of KSDs. This study aims to validate the KSD-TK by comparing it to clinical diagnoses made by the Kernicterus Clinic in the Division of Neurology. METHODS: Through retrospective chart review, we completed a KSD-TK for 37 patients evaluated between 2011 and 2019 using highest bilirubin, newborn risk factors, neonatal exam, follow-up exam, auditory testing, tooth enamel, and MRI brain results. KSD-TK results were compared to the clinical diagnoses given by a kernicterus expert (SS). RESULTS: Of 37 patients, 29 were clinically diagnosed with kernicterus, including 14/14 with KSD-TK scored as "definite", 14/15 "probable", and 1/2 with "possible" kernicterus. None of 6 patients with KSD-TK "not kernicterus" were clinically diagnosed with kernicterus. Combining KSD-TK "definite" and "probable", the KSD-TK has 96.6% sensitivity and 87.5% specificity. Each KSD-TK component had high sensitivity, but only three had specificity ≥0.75: auditory neuropathy spectrum disorder, abnormal movements and/or tone on follow-up exam, and abnormal globus pallidus and/or subthalamic nucleus on MRI. CONCLUSION: The KSD-TK is a promising screening tool for patients at risk for kernicterus. IMPACT: This study provides validation of a Kernicterus Spectrum Disorders (KSDs) Toolkit. The toolkit provides screening criteria for predicting KSD diagnosis. Scores of definite or probable have high sensitivity and specificity for KSDs. Abnormal auditory processing, exam, and MRI were most specific for KSDs.

Deep Brain Stimulation for Cockayne Syndrome-Associated Movement Disorder.

Cockayne syndrome (CS) is a rare progeroid disorder characterized by multisystem degeneration, including neurological dysfunction, for which deep brain stimulation (DBS) is a proposed treatment. This study represents only the third case of DBS for CS-associated movement disorder and the first in which both proposed targets had devices implanted, allowing for direct comparison. A case of DBS for CS-associated movement disorder is presented. Previous literature documents two cases with one targeting the ventral intermediate nucleus of the thalamus (VIM) and the other targeting the globus pallidus interna (GPi). Our patient underwent stimulation of GPi nuclei followed by repositioning to VIM nuclei with improved symptom control using VIM stimulation. In all cases, there was a significant clinical benefit without off-target effects. CS-associated movement disorder exhibits phenotypic variability for which DBS is a viable treatment. Target selection should be driven by clinical phenotype.

Failure to thrive - an overlooked manifestation of KMT2B-related dystonia: a case presentation.

BACKGROUND: KMT2B-related dystonia is a recently described form of childhood onset dystonia that may improve with deep brain stimulation. Prior reports have focused on neurologic features including prominent bulbar involvement without detailing general health consequences that may result from orolingual dysfunction. We describe a family with novel KMT2B mutation with several members with failure to thrive to highlight this non-neurologic, but consequential impact of mutation in this gene. CASE PRESENTATION: We present a case of a 15-year old female who was admitted and evaluated for failure to thrive. On exam, she had severe speech dysfluency, limited ability to protrude the tongue, and generalized dystonia involving the oromandibular region, right upper and left lower extremity with left foot inversion contracture. The proband and her parents underwent whole genome sequencing. A previously undescribed variant, c.4960 T > C (p.Cys1654Arg), was identified in the KMT2B gene in the proband and mother, and this variant was subsequently confirmed in two maternal cousins, one with failure to thrive. Literature review identified frequent reports of prominent bulbar involvement but failure to thrive is rarely mentioned. CONCLUSION: Failure to thrive is a common pediatric clinical condition that has consequences for growth and development. In the presence of an abnormal neurologic exam, a search for a specific underlying genetic etiology should be pursued. With this case series, we highlight an unusual potentially treatable cause of failure to thrive, reinforce the importance of precise molecular diagnosis for patients with failure to thrive and an abnormal neurologic exam, and underscore the importance of cascade screening of family members.

Congenital Cataracts and Gut Dysmotility in a DYNC1H1 Dyneinopathy Patient.

Whole exome sequencing continues to end the diagnostic odyssey for a number of patients and expands our knowledge of phenotypes associated with gene mutations. We describe an 11-year-old female patient with a constellation of symptoms including congenital cataracts, gut dysmotility, sensory neuropathy, and bifrontal polymicrogyria. Whole exome sequencing was performed and identified a de novo heterozygous missense mutation in the ATPase motor domain of cytoplasmic dynein heavy chain 1 (DYNC1H1), which is known to be involved in neuronal migration and retrograde axonal transport. The mutation was found to be highly damaging by multiple prediction programs. The residue is highly conserved, and reported mutations in this gene result in a variety of phenotypes similar to that of our patient. We report only the second case of congenital cataracts and the first of gut dysmotility in a patient with DYNC1H1, thus expanding the spectrum of disease seen in DYNC1H1 dyneinopathies.

Cognitive and behavioral outcomes in benign childhood epilepsy with centrotemporal spikes.

We review the evidence that BECTS may be associated with cognitive dysfunction and behavioral problems, the extent to which these problems may be associated with patterns of EEG abnormalities in BECTS, and the impact of antiepileptic medication on cognition and behavior in BECTS. A growing literature examining cognitive and behavioral outcomes suggests that children with BECTS perform below the level of their peers. Consistent with this, neuroimaging studies reveal that BECTS has an impact on structural and functional brain development, but the potential influence of frequency and lateralization of centrotemporal spikes (CTS) on cognition and behavior is not well understood. Treatment with AEDs is an option in BECTS, but existing studies have not clearly shown a clear relationship between elimination of CTS and improved cognitive or behavioral outcomes.