Age-related reference values for the pediatric Scale for Assessment and Rating of Ataxia: a multicentre study

Improving paediatric movement disorders care: Insights on rating scales utilization and clinical practice

AIM

This exploratory study evaluates rating scale usage by experts from the European Reference Network for Rare Neurological Diseases (ERN-RND) for paediatric MD, considering factors like diagnosis, intellectual disability, age, and transition to adult care. The aim is to propose a preliminary framework for consistent application.

METHODS

A multicentre survey among 25 ERN-RND experts from 10 European countries examined rating scale usage in paediatric MD, categorizing MD into acute, non-progressive, and neurodegenerative types. Factors influencing scale choice and the transition to adult care practices were analysed. A comprehensive literature search was conducted to identify the earliest age of application of these scales in paediatric patients.

RESULTS

The study identifies various rating scales and establishes their usage frequencies for different MDs. Experts highlighted the need for standardized scales and proposed preliminary evaluation strategies based on clinical contexts. Challenges in applying scales to young, non-cooperative patients were acknowledged.

INTERPRETATION

The study recommends developing standardized rating scales for paediatric MDs to improve evaluations and data collection. It suggests potential scales for specific clinical scenarios to better evaluate disease progression. Comprehensive, patient-centred care remains crucial during the transition to adult care, despite the identified challenges. This exploratory approach aims to enhance patient outcomes and care.

Evaluating mFARS in pediatric Friedreich's ataxia: Insights from the FACHILD study

OBJECTIVES

Friedreich ataxia (FRDA) is a rare genetic disorder caused by mutations in the FXN gene, leading to progressive coordination loss and other symptoms. The recently approved omaveloxolone targets this condition but is limited to patients over 16 years of age, highlighting the need for pediatric treatments due to the disorder's early onset and more rapid progression in children. This population also experiences increased non-neurological complications; the FACHILD study aimed to augment and expand the knowledge about the natural history of the disease and clinical outcome assessments for trials in children in FRDA.

METHODS

The study enrolled 108 individuals aged 7-18 years with a confirmed FRDA diagnosis, with visits occurring from October 2017 to November 2022 across three institutions. Several measures were introduced to minimize the impact of the COVID-19 pandemic, including virtual visits. Outcome measures centered on the mFARS score and its subscores, and data were analyzed using mixed models for repeated measures. For context and to avoid misinterpretation, the analysis was augmented with data from patients enrolled in the Friedreich's Ataxia Clinical Outcome Measures Study.

RESULTS

Results confirmed the general usefulness of the mFARS score in children, but also highlighted issues, particularly with the upper limb subscore (FARS B). Increased variability, limited homogeneity across study subgroups, and potential training effects might limit mFARS application in clinical trials in pediatric populations.

INTERPRETATION

The FARS E (Upright Stability) score might be a preferred outcome measure in this patient population.

[Scale for the assessment and rating of ataxia (SARA): translation and cultural adaptation to German-speaking areas]

BACKGROUND/OBJECTIVE

The scale for the assessment and rating of ataxia (SARA) is a feasible assessment for the classification and evaluation of therapeutic interventions. In order to provide access to the SARA in German, the aim of this work was to translate the SARA into German and to adapt it according to international guidelines for German-speaking countries.

METHOD

The process involved six steps. The comprehensibility of the scale was assessed using interviews with potential users.

RESULTS

A total of nine physiotherapists and six physicians working in various clinical settings were interviewed, seven of them worked in Germany and four each in Austria and Switzerland. The interviews led to a refined version of the translation. The comprehensibility testing revealed no country-specific differences.

CONCLUSION

A German version of the SARA authorized by the co-author of the original publication, is now available. The results provide methodological insights into the translation process of observation-based standardized assessments.

Ataxia Rating Scales Reveal Increased Scores in Very Preterm Born 5-6-Year-Old Preschool Children and Young Adults

The aim of this study is to investigate whether scores in ataxia rating scales (ARS) are different in very preterm (VP) preschool and adult participants compared to term controls. This is a case-control study. Sixty VP children (years: 5.5-6.5; gestational age: 23.9-31.7 weeks) and 56 VP adults (years: 17.8-27.9; gestational age: 23.3-32.0 weeks) without major cerebral lesions participated in the study; 60-age and sex-matched term children and 64 term adults for comparison were used in the study intervened with the assessment with International Cooperative Ataxia Rating Scale (ICARS) and Scale for Assessment and Rating of Ataxia (SARA). Main outcome measures are primary outcome: total icars and sara scores in preterm (vp) participants versus controls. Results showed that VP children showed significantly higher total ICARS (M 15.98, SD 6.29, range 4.0-32.0; p < .001) and SARA scores (M 6.5, SD 2.53, range 1.0-15.0; p < .001) than controls (ICARS: M 9.17, SD 3.88, range 2.0-20.0; SARA: M 3.51, SD 1.54, range 1.0-8.0). VP adults also showed significantly higher total ICARS (M 1.0, SD 1.99, range 0.0-11.0; p < .001) and SARA scores (M 0.54, SD 1.08, range 0.0-6.0; p < .001) than controls (ICARS: M 0.11, SD 0.44, range 0.0-2.0; SARA: M 0.04, SD 0.18, range 0.0-1.0). In conclusion, VP children showed significantly higher scores in ARS than controls. These differences were also present in VP adults, suggesting that deficits likely prevail until adulthood. ARS are a time and cost-effective method to screen for difficulties in coordination and balance in a patient group at risk.

Harnessing cognitive strategy use for functional problems and proposed underlying mechanisms in childhood-onset dystonia

BACKGROUND

There is a significant gap in knowledge about rehabilitation techniques and strategies that can help children and young people with hyperkinetic movement disorders (HMD) including dystonia to successfully perform daily activities and improve overall participation. A promising approach to support skill acquisition is the Cognitive Orientation to daily Occupational Performance (CO-OP) intervention. CO-OP uses cognitive strategies to help patients generate their own solutions to overcome self-identified problems encountered in everyday living.

PURPOSE

1. To identify and categorize strategies used by children with HMD to support skill acquisition during CO-OP; 2. To review the possible underlying mechanisms that might contribute to the cognitive strategies, in order to facilitate further studies for developing focused rehabilitation approaches.

METHODS

A secondary analysis was performed on video-recorded data from a previous study exploring the efficacy of CO-OP for childhood onset HMD, in which CO-OP therapy sessions were delivered by a single occupational therapist. For the purpose of this study, we reviewed a total of 40 randomly selected hours of video footage of CO-OP sessions delivered to six participants (age 6-19 years) over ten intervention sessions. An observational recording sheet was applied to identify systematically the participants' or therapist's verbalizations of cognitive strategies during the therapy. The strategies were classified into six categories in line with published literature.

RESULTS

Strategies used by HMD participants included distraction, externally focussed attention, internally focussed attention, emotion self-regulation, motor imagery and mental self-guidance. We postulate different underlying working mechanisms for these strategies, which have implications for the therapeutic management of children and young people with HMD including dystonia.

CONCLUSIONS

Cognitive strategy training can fundamentally change and improve motor performance. On-going work will address both the underlying neural mechanisms of therapeutic change and the mediators and moderators that influence how change unfolds.

Natural History of Friedreich Ataxia: Heterogeneity of Neurologic Progression and Consequences for Clinical Trial Design

BACKGROUND AND OBJECTIVES

The understanding of the natural history of Friedreich ataxia (FRDA) has improved considerably recently, but patterns of neurologic deterioration are not fully clarified, compromising the assessment of the clinical relevance of effects and guidance for study design. The goal of this study was to acknowledge the broad genetic diversity of the population, especially for younger individuals, and to provide analyses stratified by age to guide population selection in future studies.

METHODS

Based on a large natural history study, the FRDA Clinical Outcome Measures study that at the current data cut enrolled 1,115 participants, followed up for 5,287 yearly visits, we present results from the modified FRDA Rating Scale and its subscores. The secondary outcomes included the patient-reported activities of daily living scale, the timed 25-foot walk, and the 9-hole peg test. Long-term progression was modeled using slope analyses within early-onset, typical-onset, intermediate-onset, and late-onset FRDA. To reflect recruitment in clinical trials, short-term changes were analyzed within age-based subpopulations. All analyses were stratified by ambulation status.

RESULTS

Long-term progression models stratified by disease severity indicated highly differential disease progression, especially at earlier ages at onset. In the ambulatory phase, decline was driven by axial items assessed by the Upright Stability subscore of the mFARS. The analyses of short-term changes showed slower progression with increasing population age due to decreasing genetic severity. Future clinical studies could reduce population diversity, interpatient variability, and the risk of imbalanced treatment groups by selecting the study population based on the functional capacity (e.g., ambulatory status) and by strict age-based stratification.

DISCUSSION

The understanding of the diversity within FRDA populations and their patterns of functional decline provides an essential foundation for future clinical trial design including patient selection and facilitates the interpretation of the clinical relevance of progression detected in FRDA.

Development of Cerebellar Reserve

The cerebellar reserve is defined as the capacity of the cerebellum for compensation and restoration following injury. This unique cerebellar ability is attributed to various forms of synaptic plasticity that incorporate multimodal and redundant cerebellar inputs, two major features of the cerebellar circuitry. It is assumed that the cerebellar reserve is acquired from the age of 12 years after the maturation of both the cerebellar adaptative behaviors and cerebellar functional connectivity. However, acquiring the cerebellar reserve is also affected by two other factors: vulnerability and growth potential in the developing cerebellum. First, cerebellar injury during the critical period of neural circuit formation (especially during fetal and neonatal life and infancy) leads to persistent dysfunction of the cerebellum and its targets, resulting in the limitation of the cerebellar reserve. Secondly, growth potential appears to facilitate cerebellar reserve during the stage when the cerebellar reserve is still immature. Based on these findings, the present mini-review proposes a possible developmental trajectory underlying the acquisition of cerebellar reserve. We highlight the importance of studies dedicated to the understanding of the cerebellar resilience to injuries.

Application of the Scale for Assessment and Rating of Ataxia in toddlers

INTRODUCTION

In young children with early onset ataxia (EOA), quantitative rating of ataxia by the Scale for Assessment and Rating of Ataxia (SARA) is longitudinally influenced by the physiological age effect on motor coordination. To enable longitudinal quantitative interpretation of ataxia by SARA in children with EOA, the EPNS ataxia working group has previously determined SARA-scores in typically developing children (4-16 years of age). In toddlers, this information is still lacking. We therefore aimed to investigate the feasibility and reliability of SARA-scores in typically developing toddlers.

METHODS

In 57 typically developing toddlers (2-4 years), we aimed to determine the: 1. feasibility of SARA-scores, 2. age-related pre-requisites to obtain SARA-scores in toddlers over all domains, 3. SARA-score reliability, 4. mathematical age connection of SARA-scores in toddlers and older children.

RESULTS

In typically developing toddlers, the feasibility of SARA is strongly age-dependent (p < .000). After computing compensations for two age-related, unfeasible and therefore un-assessable kinetic subtasks and after allowing the videotaping of non-kinetic SARA sub-task performances at home, the SARA was fully reliably assessable in all (n = 57) toddlers (ICC = 0.732). From two to 16 years of age, SARA-scores were mathematically represented by one continuous, exponentially decreasing trend line approaching the adult-optimum at 16 years of age.

CONCLUSION

In toddlers, SARA-scores are reliably assessable, by using two age-compensations and allowing the videotaping of SARA-performances partly at home. In children with EOA, these data enable longitudinal quantification and interpretation of quantitative ataxia-scores by SARA from 2 years of age throughout childhood.

2D Gait Skeleton Data Normalization for Quantitative Assessment of Movement Disorders from Freehand Single Camera Video Recordings

Overlapping phenotypic features between Early Onset Ataxia (EOA) and Developmental Coordination Disorder (DCD) can complicate the clinical distinction of these disorders. Clinical rating scales are a common way to quantify movement disorders but in children these scales also rely on the observer's assessment and interpretation. Despite the introduction of inertial measurement units for objective and more precise evaluation, special hardware is still required, restricting their widespread application. Gait video recordings of movement disorder patients are frequently captured in routine clinical settings, but there is presently no suitable quantitative analysis method for these recordings. Owing to advancements in computer vision technology, deep learning pose estimation techniques may soon be ready for convenient and low-cost clinical usage. This study presents a framework based on 2D video recording in the coronal plane and pose estimation for the quantitative assessment of gait in movement disorders. To allow the calculation of distance-based features, seven different methods to normalize 2D skeleton keypoint data derived from pose estimation using deep neural networks applied to freehand video recording of gait were evaluated. In our experiments, 15 children (five EOA, five DCD and five healthy controls) were asked to walk naturally while being videotaped by a single camera in 1280 × 720 resolution at 25 frames per second. The high likelihood of the prediction of keypoint locations (mean = 0.889, standard deviation = 0.02) demonstrates the potential for distance-based features derived from routine video recordings to assist in the clinical evaluation of movement in EOA and DCD. By comparison of mean absolute angle error and mean variance of distance, the normalization methods using the Euclidean (2D) distance of left shoulder and right hip, or the average distance from left shoulder to right hip and from right shoulder to left hip were found to better perform for deriving distance-based features and further quantitative assessment of movement disorders.

Epidemiology of pediatric essential tremor in the United States: a systematic literature review from 2010 to 2020

Background:

Methods:

Results:

Discussion:

Wearable sensors detect impaired gait and coordination in LBSL during remote assessments

Background

Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is a rare leukodystrophy with motor impairment due to biallelic mutations in DARS2, which encodes mitochondrial aspartyl tRNA synthetase. Progressive ataxia is the primary feature.

Objective

The study objective is to determine the feasibility of remotely collecting quantitative gait and balance measures in LBSL.

Methods

The study design uses wearable accelerometers and the scale for the assessment and rating of ataxia (SARA) scale to assess gait and postural sway in LBSL and control participants' homes through video conferencing.

Results

Lateral step variability (LSV), which indicates stride variability, and elevation of the step at mid‐swing are increased for LBSL patients during brief walking tests. During stance with the eyes closed, LBSL participants show rapid accelerations and decelerations of body movement covering a large sway area and path. Both the LSV and sway area during stance with the feet together and eyes closed correlate strongly with the SARA.

Conclusions

Wearable accelerometers are valid and sensitive for detecting ataxia in LBSL patients during remote assessments. The finding of large increases in the sway area during stance with the eyes closed is intriguing since dorsal column dysfunction is universally seen in LBSL. This approach can be applied to related rare diseases that feature ataxia.

Duplication/triplication mosaicism of EBF3 and expansion of the EBF3 neurodevelopmental disorder phenotype

Deleterious variants in the transcription factor early B-cell factor 3 (EBF3) are known to cause a neurodevelopmental disorder (EBF3-NDD). We report eleven individuals with EBF3 variants, including an individual with a duplication/triplication mosaicism of a region encompassing EBF3 and a phenotype consistent with EBF3-NDD, which may reflect the importance of EBF3 gene-dosage for neurodevelopment. The phenotype of individuals in this cohort was quite mild compared to the core phenotype of previously described individuals. Although ataxia tended to wane with age, we show that cognitive difficulties may increase, and we recommend that individuals with EBF3-NDD have systematic neuropsychological follow-up.

Developmental neurobiology of cerebellar and Basal Ganglia connections

BACKGROUND

The high prevalence of mixed phenotypes of Early Onset Ataxia (EOA) with comorbid dystonia has shifted the pathogenetic concept from the cerebellum towards the interconnected cerebellar motor network. This paper on EOA with comorbid dystonia (EOA-dystonia) explores the conceptual relationship between the motor phenotype and the cortico-basal-ganglia-ponto-cerebellar network.

METHODS

In EOA-dystonia, we reviewed anatomic-, genetic- and biochemical-studies on the comorbidity between ataxia and dystonia.

RESULTS

In a clinical EOA cohort, the prevalence of dystonia was over 60%. Both human and animal studies converge on the underlying role for the cortico-basal-ganglia-ponto-cerebellar network. Genetic -clinical and -in silico network studies reveal underlying biological pathways for energy production and neural signal transduction.

CONCLUSIONS

EOA-dystonia phenotypes are attributable to the cortico-basal-ganglia-ponto-cerebellar network, instead of to the cerebellum, alone. The underlying anatomic and pathogenetic pathways have clinical implications for our understanding of the heterogeneous phenotype, neuro-metabolic and genetic testing and potentially also for new treatment strategies, including neuro-modulation.

Genetic and Clinical Predictors of Ataxia in Pediatric Primary Mitochondrial Disorders

Evaluation of ataxia in children is challenging in clinical practice. This is particularly true for highly heterogeneous conditions such as primary mitochondrial disorders (PMD). This study aims to explore cerebellar and brain abnormalities identified on MRI as potential predictors of ataxia in patients with PMD and, likewise, to determine the effect of the patient's genetic profile on these predictors as well as determination of the temporal relationship of clinical ataxia with MRI findings. We evaluated clinical, radiological, and genetic characteristics of 111 PMD patients younger than 21 years of age at The Children's Hospital of Philadelphia. Data was extracted from charts. Blinded radiological evaluations were carried out by experienced neuroradiologists. Multivariate logistic regression and generalized equation estimates were used for analysis. Ataxia was identified in 41% of patients. Cerebellar atrophy or putaminal involvement with mitochondrial DNA (mtDNA) mutations (OR 1.18, 95% CI 1.1-1.3, p < 0.001) and nuclear DNA mutation with no atrophy of the cerebellum (OR 1.14, 95% CI 1.0-1.3, p = 0.007) predicted an increased likelihood of having ataxia per year of age. Central tegmental tract predicted the presence of ataxia independent of age and pathogenic variant origin (OR 9.8, 95% CI 2-74, p = 0.009). Ataxia tended to precede the imaging finding of cerebellar atrophy. Cerebellar atrophy and putaminal involvement on MRI of pediatric-onset PMD may predict the presence of ataxia with age in patients with mtDNA mutations. This study provides predicted probabilities of having ataxia per year of age that may help in family counseling and future research of the population.

Ataxia and mobility in children following surgical resection of posterior fossa tumour: A longitudinal cohort study

PURPOSE

To report the course of ataxia in children up to 2 years post-operatively, following surgical resection of a posterior fossa tumour (PFT).

METHODS

Thirty-five children, (median age 9 years, range 4-15) having resection of PFT, were assessed using the Scale for the Assessment and Rating of Ataxia (SARA), Brief Ataxia Rating Scale (BARS) and the mobility domain of the Paediatric Evaluation of Disability Index (PEDI-m) at initial post-operative period (baseline), 3 months, 1 year and 2 years post-operatively.

RESULTS

Baseline median scores of the SARA and BARS were 8.5 (range 0-35.5), and 7 (0-25) respectively. Ataxia improved at 3 months (median SARA and BARS reduction 3.5 and 4, respectively). Additional gradual improvements in SARA were recorded at 1 (median reduction 2) and 2 years post-operatively (median reduction 0.5). Median baseline PEDI-m was 54.75 (range 15.2-100) with improvement at 3 months (median increase 36.95) and small improvement at 1 year (median increase 2.5) and 2 years (median increase 5.8). Children with medulloblastoma and midline tumours (median baseline SARA 10 and 11, respectively) demonstrated more severe ataxia than children with low-grade gliomas and unilateral tumours (median baseline SARA 7.5 and 6.5, respectively).

CONCLUSION

The largest improvement in ataxia scores and functional mobility scores is demonstrated within the first 3 months post-operatively, but ongoing gradual improvement is observed at 2 years. Children with medulloblastoma and midline tumour demonstrated higher ataxia scores long term.

Application of the Scale for the Assessment and Rating of Ataxia (SARA) in pediatric oncology patients: A multicenter study

Posterior cranial fossa (PCF) tumors in childhood are often associated with ataxia as well as other motor, neurobehavioral and linguistic impairment. The use of a reliable outcome measure is mandatory to evaluate the severity of impairment and monitor rehabilitation effectiveness. The aim of this work is to explore the validity of the Scale for the Assessment and Rating of Ataxia (SARA) in pediatric subjects with ataxia secondary to PCF tumor resection and evaluate the influence of age and comorbidities. Seventy eight patients (3-18 years) were recruited in 5 centers from 2016 to 2018. The age effect on SARA was analyzed by correlating total SARA scores and item scores with age and gradually excluding youngest subjects. The comorbidity effect was evaluated by comparing the ataxia-only group vs a group of subjects with ataxia + dysfunction of cranial nerves or cerebellar mutism (CM) and a group of patients with ataxia + hemiparesis. Several negative correlations between SARA scores and age were found under age 9. Differences between ataxia-only group and the other two groups were closely associated with specific comorbidities (e.g. speech disturbance in cranial nerves or CM group (p value < 0.001) and gait, stance, sitting and finger chase in the hemiparetic group (mean p value 0.022)).

Validation of low-cost system for gait assessment in children with ataxia

BACKGROUND

Ataxic syndromes include several rare, inherited and acquired conditions. One of the main issues is the absence of specific, and sensitive automatic evaluation tools and digital outcome measures to obtain a continuous monitoring of subjects' motor ability.

OBJECTIVES

This study aims to test the usability of the Kinect system for assessing ataxia severity, exploring the potentiality of clustering algorithms and validating this system with a standard motion capture system.

METHODS

Gait evaluation was performed by standardized gait analysis and by Kinect v2 during the same day in a cohort of young patient (mean age of 13.8±7.2). We analyzed the gait spatio-temporal parameters and we looked at the differences between the two systems through correlation and agreement tests. As well, we tested for possible correlations with the SARA scale as well. Finally, standard classification algorithm and principal components analysis were used to discern disease severity and groups.

RESULTS

We found biases and linear relationships between all the parameters. Significant correlations emerged between the SARA and the Speed, the Stride Length and the Step Length. PCA results, highlighting that a machine learning approach combined with Kinect-based evaluation shows great potential to automatically assess disease severity and diagnosis.

CONCLUSIONS

The spatio-temporal parameters measured by Kinect cannot be used interchangeably with those parameters acquired with standard motion capture system in clinical practice but can still provide fundamental information. Specifically, these results might bring to the development of a novel system to perform easy and quick evaluation of gait in young patients with ataxia, useful for patients stratification in terms of clinical severity and diagnosis.

Dyskinesia Impairment Scale scores in Dutch pre-school children after neonatal therapeutic hypothermia

BACKGROUND

Neonatal therapeutic hypothermia (TH) can ameliorate or prevent the development of dyskinetic cerebral palsy (CP) after hypoxic-ischemic encephalopathy (HIE). The Dyskinesia Impairment Scale (DIS) was recently launched to quantify dyskinetic (dystonic and choreatic) motor features in patients with CP. In TH treated children, who are at risk of developing dyskinetic CP, we aimed to determine DIS-scores at pre-school age.

METHOD

In 21 Dutch pre-school children (3-6 years of age) who had received TH according to the Dutch-Flemish treatment protocol, we determined DIS-scores. We associated DIS-scores with 1. age-matched control values (Kuiper et al., 2018) [1], and 2. previously reported DIS-score range in dyskinetic CP (Monbaliu E et al., 2015).

RESULTS

The motor phenotype was determined as: normal (n = 18/21), mildly impaired (reduced coordination (n = 2/21)) and abnormal (dyskinetic CP; n = 1/21). In absence of CP (n = 20/21), DIS-scores were lower (more favorable) than in dyskinetic CP, without any overlapping group scores (mean difference: 71 points; p < .05). However, the obtained DIS-scores were still higher than previously reported in healthy age-matched controls (mean difference: 14 points; p < .05). There was an association between DIS-scores and retrospective neonatal MRI (basal ganglia and thalamus injury on diffusion weighted imaging (DWI)) and (a)EEG parameters (p < .05).

CONCLUSION

In the vast majority (95%) of Dutch TH-HIE treated pre-school children, the phenotypic motor outcome was favorable. However, DIS-scores were moderately increased compared with healthy age-matched controls. Future studies may elucidate the significance of moderately increased DIS-scores should to further extent.

Post-operative cerebellar mutism syndrome: rehabilitation issues

INTRODUCTION

Tumors of the cerebellum are the most common brain tumors in children. Modern treatment and aggressive surgery have improved the overall survival. Consequently, growing numbers of survivors are at high risk for developing adverse and long-term neurological deficits including deficits of cognition, behavior, speech, and language. Post-operative cerebellar mutism syndrome (pCMS) is a well-known and frequently occurring complication of cerebellar tumor surgery in children. In the acute stage, children with pCMS may show deterioration of cerebellar motor function as well as pyramidal and cranial neuropathies. Most debilitating is the mutism or the severe reduction of speech and a range of neurobehavioral symptoms that may occur. In the long term, children that recover from pCMS continue to have more motor, behavioral, and cognitive problems than children who did not develop pCMS after cerebellar tumor surgery. The severity of these long-term sequelae seems to be related to the length of the mute phase.

AIM OF THIS NARRATIVE REVIEW

The impact of pCMS on patients and families cannot be overstated. This contribution aims to discuss the present knowledge on the natural course, recovery, and rehabilitation of children with pCMS. We suggest future priorities in developing rehabilitation programs in order to improve the long-term quality of life and participation of children after cerebellar tumor surgery and after pCMS in particular.

Development of SaraHome: A novel, well-accepted, technology-based assessment tool for patients with ataxia

BACKGROUND AND OBJECTIVE

Early onset ataxias (EOAs) are a heterogeneous group of neurological conditions, responsible for severe motor disability in paediatric age, which still lack reliable outcome measures. Available scales to assess ataxia, such as the Scale for Assessment and Rating of Ataxia (SARA), are based on subjective assessment of specific motor and language tasks by an examiner, and therefore is age dependent and lacks accuracy in detecting small variations in disease severity. In last years, novel technologies, including computer interfaces and videogames, have emerged for clinical applications and the advent of Internet of Medical Things and of Information Communication Technology have allowed the remote control of such technologies. This pilot study describes a newly developed tool (SaraHome) for the assessment at home of EOA evaluating its feasibility and acceptability on a small sample of children.

METHODS

Ten EOA children and ten caregivers have been enrolled for a preliminary outpatient evaluation. The Microsoft Kinect 2.0 and Leap Motion Controller (LMC) connected to a personal computer with an ad hoc software have been set-up, for the acquisition of standardized motor tasks performed by the patients with the caregivers' assistance. Acceptance and practicability have been tested by QUEST 2.0 and IMI questionnaires in caregivers and patients respectively.

RESULTS

The SaraHome software was developed, based on a collection of services provided by a complex architecture that consists of a Restful interface, which enables to access a series of plugins for the execution of different tasks. A graphical user interface allows the acquisition of the patient movements while performing a motor task. A protocol of standard tasks inspired by SARA was established, and a system of video-assisted instruction provided. The set-up for the optimal acquisition of such protocol by Kinect and LMC has been defined. Both patients and caregivers accomplished the SaraHome assessment with good feedback at the technology acceptance questionnaires.

CONCLUSIONS

SaraHome represents a newly developed tool for the assessment of ataxia in patients, resulting from the integration of low-cost and easy-accessible technologies. This pilot application highlighted the feasibility and the acceptability of the system, suggesting the potential use in clinical practice.

Exercise and Physical Therapy Interventions for Children with Ataxia: A Systematic Review

The effectiveness of exercise and physical therapy for children with ataxia is poorly understood. The aim of this systematic review was to critically evaluate the range, scope and methodological quality of studies investigating the effectiveness of exercise and physical therapy interventions for children with ataxia. The following databases were searched: AMED, CENTRAL, CDSR, CINAHL, ClinicalTrials.gov, EMBASE, Ovid MEDLINE, PEDro and Web of Science. No limits were placed on language, type of study or year of publication. Two reviewers independently determined whether the studies met the inclusion criteria, extracted all relevant outcomes, and conducted methodological quality assessments. A total of 1988 studies were identified, and 124 full texts were screened. Twenty studies were included in the review. A total of 40 children (aged 5-18 years) with ataxia as a primary impairment participated in the included studies. Data were able to be extracted from eleven studies with a total of 21 children (aged 5-18 years), with a range of cerebellar pathology. The studies reported promising results but were of low methodological quality (no RCTs), used small sample sizes and were heterogeneous in terms of interventions, participants and outcomes. No firm conclusions can be made about the effectiveness of exercise and physical therapy for children with ataxia. There is a need for further high-quality child-centred research.

Paediatric motor phenotypes in early-onset ataxia, developmental coordination disorder, and central hypotonia

AIMS

To investigate the accuracy of phenotypic early-onset ataxia (EOA) recognition among developmental conditions, including developmental coordination disorder (DCD) and hypotonia of central nervous system origin, and the effect of scientifically validated EOA features on changing phenotypic consensus.

METHOD

We included 32 children (4-17y) diagnosed with EOA (n=11), DCD (n=10), and central hypotonia (n=11). Three paediatric neurologists independently assessed videotaped motor behaviour phenotypically and quantitatively (using the Scale for Assessment and Rating of Ataxia [SARA]). We determined: (1) phenotypic interobserver agreement and phenotypic homogeneity (percentage of phenotypes with full consensus by all three observers according to the underlying diagnosis); (2) SARA (sub)score profiles; and (3) the effect of three scientifically validated EOA features on phenotypic consensus.

RESULTS

Phenotypic homogeneity occurred in 8 out of 11, 2 out of 10, and 1 out of 11 patients with EOA, DCD, and central hypotonia respectively. Homogeneous phenotypic discrimination of EOA from DCD and central hypotonia occurred in 16 out of 21 and 22 out of 22 patients respectively. Inhomogeneously discriminated EOA and DCD phenotypes (5 out of 21) revealed overlapping SARA scores with different SARA subscore profiles. After phenotypic reassessment with scientifically validated EOA features, phenotypic homogeneity changed from 16 to 18 patients.

INTERPRETATION

In contrast to complete distinction between EOA and central hypotonia, the paediatric motor phenotype did not reliably distinguish between EOA and DCD. Reassessment with scientifically validated EOA features could contribute to a higher phenotypic consensus. Early-onset ataxia (EOA) and central hypotonia motor phenotypes were reliably distinguished. EOA and developmental coordination disorder (DCD) motor phenotypes were not reliably distinguished. The EOA and DCD phenotypes have different profiles of the Scale for Assessment and Rating of Ataxia.

Turkish version of Brief Ataxia Rating Scale

AIM

Our aim was to perform the Turkish-language adaptation of a practical ataxia rating scale for children.

METHODS

The Brief Ataxia Rating Scale was subjected to cultural adaptation following receipt of the requisite permissions. Thirty-six children aged 4-18 years followed-up with a diagnosis of ataxia were included in the study. Evaluation of each child was recorded on video. The video recordings were scored independently by nine observers (four physiotherapists, one pediatric neurologist, and four pediatricians). Intra-rater reliability was tested by the same video images being scored twice, at 15-day intervals, by a pediatric neurologist. Intraclass correlation coefficients were used for inter-rater and intra-rater reliability. The Scale for the Assessment and Rating of Ataxia was used for concurrent validity.

RESULTS

Good to excellent reliability was determined among the nine observers in terms of total scores with the intraclass correlation coefficient among the nine observers (intraclass correlation coefficient = 0.926; 95% CI: 0.885-0.956). Intra-rater reliability analysis results exhibited strong reliability in terms of scores elicited at two-week intervals (intraclass correlation coefficient = 0.967; 95% CI: 0.890-0.987, r = 0.97, p < 0.001). At concurrent validity analysis, a strong relation was determined between total Scale of the Assessment and Rating of Ataxia score and total Brief Ataxia Rating Scale score (r = 0.942, p < 0.001).

CONCLUSION

The Turkish-language adaptation of the Brief Ataxia Rating Scale is reliable and valid for application in children.Implications for RehabilitationThis study shows the reliability and validity of the Turkish language adaptation of brief ataxia rating scale in children.The scale being both practical and easily applicable to ataxic children will contribute to broadening its use in the pediatric age group in particular.

A clinical diagnostic algorithm for early onset cerebellar ataxia

Early onset cerebellar Ataxia (EOAc) comprises a large group of rare heterogeneous disorders. Determination of the underlying etiology can be difficult given the broad differential diagnosis and the complexity of the genotype-phenotype relationships. This may change the diagnostic work-up into a time-consuming, costly and not always rewarding task. In this overview, the Childhood Ataxia and Cerebellar Group of the European Pediatric Neurology Society (CACG-EPNS) presents a diagnostic algorithm for EOAc patients. In seven consecutive steps, the algorithm leads the clinician through the diagnostic process, including EOA identification, application of the Inventory of Non-Ataxic Signs (INAS), consideration of the family history, neuro-imaging, laboratory investigations, genetic testing by array CGH and Next Generation Sequencing (NGS). In children with EOAc, this algorithm is intended to contribute to the diagnostic process and to allow uniform data entry in EOAc databases.

Distinguishing Patients With a Coordination Disorder From Healthy Controls Using Local Features of Movement Trajectories During the Finger-to-Nose Test

Assessment of coordination disorders is valuable for monitoring progression of patients, distinguishing healthy and pathological conditions, and ultimately aiding in clinical decision making, thereby offering the possibility to improve medical care or rehabilitation. A common method to assess movement disorders is by using clinical rating scales. However, rating scales depend on the evaluation and interpretation of an observer, implying that subjective phenotypic assignment precedes the application of the scales. Objective and more accurate methods are under continuous development but gold standards are still scarce. Here, we show how a method we previously developed, originally aimed at assessing dynamic balance by a probabilistic generalized linear model, can be used to assess a broader range of functional movements. In this paper, the method is applied to distinguish patients with coordination disorders from healthy controls. We focused on movements recorded during the finger-to-nose task (FNT), which is commonly used to assess coordination disorders. We also compared clinical FNT scores and model scores. Our method achieved 84% classification accuracy in distinguishing patients and healthy participants, using only two features. Future work could entail testing the reliability of the method by using additional features and other clinical tests such as finger chasing, quiet standing, and/or usage of tracking devices such as depth cameras or force plates.

Non-invasive Focal Mechanical Vibrations Delivered by Wearable Devices: An Open-Label Pilot Study in Childhood Ataxia

Non-invasive focal mechanical vibrations (NIFMV) now represent a strategy of increasing interest to improve motor control in different neurological diseases. Nanotechnology allowed the creation of wearable devices transforming thermal variations into mechanical energy with focal vibrations. This kind of wearable stimulators (WS) has produced encouraging preliminary results when used in the treatment of movement disorders and ataxia in adults. In this open label pilot study we first evaluated the feasibility, safety and effectiveness of NIFMV by WS in a cohort of 10 patients with childhood ataxia, a phenomenological category including different conditions still lacking of effective symptomatic therapies. Through the assessment of both clinical rating scales and spatio-temporal gait parameters via standardized gait analysis, we observed that a 4 weeks long treatment with WS Equistasi® was safe and provided significantly different effects in stride features of patients with slow/non-progressive cerebellar ataxia and Friedreich's Ataxia. Although limited by the sample size, the absence of a placebo-controlled group, the poor compliance of enrolled population to the original experimental design and the partial accuracy of outcome measures in pediatric subjects, we suggest that NIFMV by WS could support locomotion of patients with childhood slow/non-progressive cerebellar ataxia with preserved sensory system and no signs of peripheral neuropathy. Future studies are definitely necessary to confirm these preliminary results and define criteria for successful NIFMV-based treatment

Incidence and prognostic factors of ataxia in children with posterior fossa tumors

Background

There is minimal literature specific to motor outcomes in children with posterior fossa tumors (PFTs) despite ataxia being a significant problem in this group. This study aims to report children's physical outcomes following management of PFT and determine which factors affect severity of ataxia and functional limitations.

Methods

Forty-two children aged between 5 and 17 and between 1 and 4 years following surgery for PFT were assessed using the Scale for the Assessment and Rating of Ataxia (SARA), the Brief Ataxia Rating Scale (BARS), and the mobility Pediatric Evaluation of Disability Inventory (PEDI) subscale to determine prevalence and severity of ataxia and a measure of physical function. Analysis was undertaken comparing impact of tumor location, tumor histology, adjuvant treatment, age at diagnosis, presence of preoperative ataxia, and presence of cerebellar mutism syndrome (CMS) on ataxia and physical function scores.

Results

Seventy-one percent of children demonstrated a SARA and BARS score greater than 2. A total of 48% of children had a PEDI-m score greater than 90. There was no correlation between age at diagnosis or preoperative ataxia and assessment scores. There was a significant difference in SARA/BARS and PEDI-mobility scores depending on tumor histology, tumor location, and presence of CMS.

Conclusions

A high proportion of children (>1 year) following surgery for PFT continue to present with ataxia. Higher ataxia and lower physical function scores were demonstrated in children with medulloblastoma and midline tumors and those diagnosed with CMS. The high prevalence of ataxia demonstrates the need for further research regarding rehabilitation management in this population.

Current behavioral assessments of movement disorders in children

Pediatric movement disorders (PMDs) are common and have recently received increasing attention. As these disorders have special clinical features, the selection of appropriate behavioral assessment tools that can clearly distinguish movement disorders from other diseases (eg, epilepsy and neuromuscular disorders) is crucial for achieving an accurate diagnosis and treatment. However, few studies have focused on behavioral assessments in children. The present report attempts to provide a critical review of the available subjective and objective assessment tests for common PMDs. We believe that the principles of objectification, multi-purpose use, and simplification are also applicable to the selection and development of satisfactory pediatric behavioral assessment tools. We expect that the development of wearable sensors, virtual reality, and augmented reality will lead to the establishment of more reliable and simple tests. In addition, more rigorous randomized controlled trials that have been specifically designed to evaluate behavioral testing in children are also expected in the future.

Physiological movement disorder-like features during typical motor development

AIM

To compare physiological age-relatedness between dyskinesia (dystonia/choreoathetosis), dystonia and ataxia rating scale scores in healthy children.

METHOD

Three movement disorders specialists quantified dyskinetic-like features in healthy children (n = 52; 4-16 years) using the Dyskinesia Impairment Scale (DIS = DIS-choreoathetosis (DIS-C) + DIS-dystonia (DIS-D)). We compared the age-related regression coefficients of the DIS with data processed from previous studies on dystonia and ataxia rating scales (Burke-Fahn-Marsden Movement and Disability Scales (BFMMS and BFMDS) and Scale for Assessment and Rating of Ataxia (SARA), International Cooperative Ataxia Rating Scale (ICARS) and Brief Ataxia Rating Scale (BARS)).

RESULTS

Dyskinetic scores were obtained in 79% (DIS); 65% (DIS-D) and 17% (DIS-C) versus dystonic and ataxic scores in 98% (BFMMS) and 89% (SARA/ICARS/BARS) of the children. Age-related DIS and DIS-D scores (B = -0.90 and 0.77; p < 0.001) were correlated with age-related BFMMS scores (B = -0.49; p < 0.001; r = 0.87; p < 0.001), whereas DIS-C scores were age-independent. Ataxic scores revealed stronger age-related regression coefficients than dyskinetic and dystonic scores (4-8 years; p < 0.05).

INTERPRETATION

In healthy children, comparison between physiological dyskinesia, dystonia and ataxia rating scale scores revealed: 1. inverse age-relatedness for dystonic and ataxic scores, but not for choreoathetotic scores, 2. interrelated dystonic DIS-D and BFMMS scores, 3. the strongest age-related expression by ataxic scores. In healthy children, these physiological movement disorder-like features are interpreted as an expression of the developing underlying motor centres.

Cerebellar motor syndrome from children to the elderly

More than a century after the description of its cardinal components, the cerebellar motor syndrome (CMS) remains a cornerstone of daily clinical ataxiology, in both children and adults. Anatomically, motor cerebellum involves lobules I-V, VI, and VIII. CMS is typically associated with errors in the metrics of voluntary movements and a lack of coordination. Symptoms and motor signs consist of speech deficits, impairments of limb movements, and abnormalities of posture/gait. Ataxic dysarthria has a typical scanning (explosive with staccato) feature, voice has a nasal character, and speech is slurred. Cerebellar mutism is most common in children and occurs after resection of a large midline cerebellar tumor. Ataxia of limbs includes at various degrees dysmetria (hypermetria: overshoot, hypometria: undershoot), dysdiadochokinesia, cerebellar tremor (action tremor, postural tremor, kinetic tremor, some forms of orthostatic tremor), isometrataxia, disorders of muscle tone (both hypotonia and cerebellar fits), and impaired check and rebound. Handwriting is irregular and some patients exhibit megalographia. Cerebellar patients show an increased body sway with a broad-based stance (ataxia of stance). Gait is irregular and staggering. Delayed learning of complex motor skills may be a prominent feature in children. CMS is currently explained by the inability of the cerebellum to handle feedback signals during slow movements and to create, store, select, and update internal models during fast movements. The cerebellum is embedded in large-scale brain networks and is essential to perform accurate motor predictions related to body dynamics and environmental stimuli. Overall, the observations in children and adults exhibiting a CMS fit with the hypothesis that the cerebellum contains neural representations reproducing the dynamic properties of body, and generates and calibrates sensorimotor predictions. Therapies aiming at a reinforcement or restoration of internal models should be implemented to cancel CMS in cerebellar ataxias. The developmental trajectory of the cerebellum, the immature motor behavior in children, and the networks implicated in CMS need to be taken into account.

Construct Validity and Reliability of the SARA Gait and Posture Sub-scale in Early Onset Ataxia

Aim: In children, gait and posture assessment provides a crucial marker for the early characterization, surveillance and treatment evaluation of early onset ataxia (EOA). For reliable data entry of studies targeting at gait and posture improvement, uniform quantitative biomarkers are necessary. Until now, the pediatric test construct of gait and posture scores of the Scale for Assessment and Rating of Ataxia sub-scale (SARA) is still unclear. In the present study, we aimed to validate the construct validity and reliability of the pediatric (SARA_GAIT/POSTURE) sub-scale. Methods: We included 28 EOA patients [15.5 (6-34) years; median (range)]. For inter-observer reliability, we determined the ICC on EOA SARA_GAIT/POSTURE sub-scores by three independent pediatric neurologists. For convergent validity, we associated SARA_GAIT/POSTURE sub-scores with: (1) Ataxic gait Severity Measurement by Klockgether (ASMK; dynamic balance), (2) Pediatric Balance Scale (PBS; static balance), (3) Gross Motor Function Classification Scale -extended and revised version (GMFCS-E&R), (4) SARA-kinetic scores (SARA_KINETIC; kinetic function of the upper and lower limbs), (5) Archimedes Spiral (AS; kinetic function of the upper limbs), and (6) total SARA scores (SARA_TOTAL; i.e., summed SARA_GAIT/POSTURE, SARA_KINETIC, and SARA_SPEECH sub-scores). For discriminant validity, we investigated whether EOA co-morbidity factors (myopathy and myoclonus) could influence SARA_GAIT/POSTURE sub-scores. Results: The inter-observer agreement (ICC) on EOA SARA_GAIT/POSTURE sub-scores was high (0.97). SARA_GAIT/POSTURE was strongly correlated with the other ataxia and functional scales [ASMK (r_s = -0.819; p < 0.001); PBS (r_s = -0.943; p < 0.001); GMFCS-E&R (r_s = -0.862; p < 0.001); SARA_KINETIC (r_s = 0.726; p < 0.001); AS (r_s = 0.609; p = 0.002); and SARA_TOTAL (r_s = 0.935; p < 0.001)]. Comorbid myopathy influenced SARA_GAIT/POSTURE scores by concurrent muscle weakness, whereas comorbid myoclonus predominantly influenced SARA_KINETIC scores. Conclusion: In young EOA patients, separate SARA_GAIT/POSTURE parameters reveal a good inter-observer agreement and convergent validity, implicating the reliability of the scale. In perspective of incomplete discriminant validity, it is advisable to interpret SARA_GAIT/POSTURE scores for comorbid muscle weakness.