Validation of the Italian version of a patient-reported outcome measure for Hereditary Spastic Paraplegia

BACKGROUND AND AIM

Patient-reported outcome measures (PROMs) are recognized as valuable measures in the clinical setting. In 2018 we developed the Italian version of the "Hereditary Spastic Paraplegia-Self Notion and Perception Questionnaire" (HSP-SNAP), a disease-specific questionnaire that collects personal perception on motor symptoms related to HSP such as stiffness, weakness, imbalance, reduced endurance, fatigue and pain. In this study our primary aim was to assess the questionnaire validity and reliability. Our secondary aim was to characterize the symptoms "perceived" by patients with HSP and compare them with those "perceived" by age-matched healthy subjects.

METHODS

The 12-item HSP-SNAP questionnaire was submitted to 20 external judges for comprehensibility and to 15 external judges for content validity assessment. We recruited 40 subjects with HSP and asked them to fill the questionnaire twice for test-retest procedure. They also completed the Medical Outcome Survey Short Form (SF-36) and were evaluated by the Spastic Paraplegia Rating Scale and the Six-Minute Walk Test. We also recruited 44 healthy subjects who completed the HSP-SNAP once to test score variability.

RESULTS

The HSP-SNAP content validity index was high (0.8±0.1) and the test-retest analysis showed high reliability (ICC = 0.94). The mean HSP-SNAP score (score range 0-48) of the HSP group was 22.2±7.8, which was significantly lower than healthy subjects (43.1±6.3). The most commonly perceived symptom was stiffness, followed by weakness and imbalance.

CONCLUSION

Although HSP-SNAP does not investigate non-motor symptoms and we validated only its Italian version, it showed good validity and reliability and it could be used in combination with other objective outcome measures for clinical purposes or as endpoints for future clinical rehabilitation studies.

TRIAL REGISTRATION

Trial Registration: ClinicalTrial.gov, NCT04256681. Registered 3 February 2020.

Effectiveness of rehabilitation intervention in persons with Friedreich ataxia

Introduction

The relevance of rehabilitation in progressive neurological disorders, such as Friedreich's Ataxia (FRDA), has yet to be convincingly proven. FRDA is characterized by ataxia, loss of gait, scoliosis, cardiomyopathy, dysarthria and dysphagia, with reduced life expectancy. The disease onset is usually in adolescence, leading to progressive disability. Omaveloxolone has been recently approved as the first pharmacological treatment for FRDA in adults and adolescents aged 16 years and older. Regarding non-pharmacological therapies, neurorehabilitation is a valuable aid in addressing the symptoms and in maintaining the residual functioning. We performed a prospective observational cohort study to evaluate the efficacy of inpatient rehabilitation (IR) for people with FRDA.

Methods

A total of 42 individuals (29 adults and 13 children) with FRDA were recruited. There were 27 ambulant and 15 non-ambulant participants. The patients underwent IR of 3 and 4 weeks in children and adults, respectively. The IR treatment was designed to be applied within a multidisciplinary setting, so FRDA patients underwent, in addition to physiotherapy, also occupational therapy, practical manual activities and psychological support aiming to enhance transferable skills useful in the activities of daily living. The primary outcome was the Scale for the Assessment and Rating of Ataxia (SARA). Other measures were: Friedreich Ataxia Rating Scale (FARS) and Nine Hole Peg Test (NHPT). Furthermore, we used the 6 Minute Walk Test (6MWT), the Timed Up and Go (TUG) and the Berg Balance Scale (BBS) only on ambulant subjects. Outcomes were evaluated at baseline and at the end of the treatment.

Results

We report that the IR significantly improves motor performance and ataxia symptoms in patients with FRDA. Our study shows significant functional improvement in all the outcome measures used, except for NHPT bilaterally. FARS and SARA scores post-IR are significatively reduced when compared (p < 0.001).

Discussion

We demonstrate that IR programs in FRDA can provide a meaningful clinical improvement in terms of outcome measures. These findings could be useful when approaching progressive neurological disorders.

Caspr1 antibodies autoimmune paranodopathy with severe tetraparesis: Potential relevance of antibody titers in monitoring treatment response

AIM

Nodopathies and paranodopathies are autoimmune neuropathies associated with antibodies to nodal-paranodal antigens (neurofascin 140/186 and 155, contactin-1, contactin-associated protein 1 [Caspr1]) characterized by peculiar clinical features, poor response to standard immunotherapies (e.g., intravenous immunoglobulins, IVIg). Improvement after anti-CD20 monoclonal antibody therapy has been reported. Data on Caspr1 antibodies pathogenicity are still preliminary, and longitudinal titers have been poorly described.

METHODS

We report on a young woman who developed a disabling neuropathy with antibodies to the Caspr1/contactin-1 complex showing a dramatic improvement after rituximab therapy, mirrored by the decrease of antibody titers.

RESULTS

A 26-year-old woman presented with ataxic-stepping gait, severe motor weakness at four limbs, and low frequency postural tremor. For neurophysiological evidence of demyelinating neuropathy, she was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy and treated with IVIg without benefit. MRI showed symmetrical hypertrophy and marked signal hyperintensity of brachial and lumbosacral plexi. Cerebrospinal fluid showed 710 mg/dL protein. Despite intravenous methylprednisolone, the patient progressively worsened, and became wheelchair-bound. Antibodies to nodal-paranodal antigens were searched for by ELISA and cell-based assay. Anticontactin/Caspr1 IgG4 antibodies resulted positive. The patient underwent rituximab therapy with slow progressive improvement that mirrored the antibodies titer, measured throughout the disease course.

CONCLUSIONS

Our patient had a severe progressive course with early disability and axonal damage, and slow recovery starting only a few months after antibody-depleting therapy. The close correlation between titer, disability, and treatment, supports the pathogenicity of Caspr1 antibodies, and suggest that their longitudinal evaluation might provide a potential biomarker to evaluate treatment response.

Harmonization of ICF Body Structures and ICD-11 Anatomic Detail: One foundation for multiple classifications

The Family of International Classifications of the World Health Organization (WHO-FIC) currently includes three reference classifications, namely International Classification of Diseases (ICD), International Classification of Functioning, Disability, and Health (ICF), and International Classification of Health Interventions (ICHI). Recently, the three classifications have been incorporated into a single WHO-FIC Foundation that serves as the repository of all concepts in the classifications. Each classification serves a specific classification need. However, they share some common concepts that are present, in different forms, in two or all of them. For the WHO-FIC Foundation to be a logically consistent repository without duplicates, these common concepts must be reconciled. One important set of shared concepts is the representation of human anatomy entities, which are not always modeled in the same way and with the same level of detail. To understand the relationships among the three anatomical representations, an effort is needed to compare them, identifying common areas, gaps, and compatible and incompatible modeling. The work presented here contributes to this effort, focusing on the anatomy representations in ICF and ICD-11. For this aim, three experts were asked to identify, for each entity in the ICF Body Structures, one or more entities in the ICD-11 Anatomic Detail that could be considered identical, broader or narrower. To do this, they used a specifically developed web application, which also automatically identified the most obvious equivalences. A total of 631 maps were independently identified by the three mappers for 218 ICF Body Structures, with an interobserver agreement of 93.5%. Together with 113 maps identified by the software, they were then consolidated into 434 relations. The results highlight some differences between the two classifications: in general, ICF is less detailed than ICD-11; ICF favors lumping of structures; in very few cases, the two classifications follow different anatomic models. For these issues, solutions have to be found that are compliant with the WHO approach to classification modeling and maintenance.

Data from the European registry for patients with McArdle disease (EUROMAC): functional status and social participation

BACKGROUND

The European registry for individuals with GSD5 and other muscle glycogenosis (EUROMAC) was launched to register rare muscle glycogenosis in Europe, to facilitate recruitment for research trials and to learn about the phenotypes and disseminate knowledge about the diseases. A network of twenty collaborating partners from eight European countries and the US contributed data on rare muscle glycogenosis in the EUROMAC registry.

METHODS

Following the initial report on demographics, neuromuscular features and comorbidity (2020), we here present the data on social participation, previous and current treatments (medication, supplements, diet and rehabilitation) and limitations. Furthermore, the following questionnaires were used: Fatigue severity scale (FSS), WHO Disability Assessment Scale (DAS 2.0), health related quality of life (SF36) and International Physical Activity Questionnaire (IPAQ).

RESULTS

Of 282 participants with confirmed diagnoses of muscle glycogenosis, 269 had GSD5. Of them 196 (73%) completed all questionnaires; for the others, the data were incomplete. The majority, 180 (67%) were currently working. Previous medical treatments included pain medication (23%) and rehabilitation treatment (60%). The carbohydrate-rich diet was reported to be beneficial for 68%, the low sucrose diet for 76% and the ketogenic diet for 88%. Almost all participants (93%) reported difficulties climbing stairs. The median FSS score was 5.22, indicating severe fatigue. The data from the WHODAS and IPAQ was not of sufficient quality to be interpreted.

CONCLUSIONS

The EUROMAC registry have provided insight into the functional and social status of participants with GSD5: most participants are socially active despite limitations in physical and daily life activities. Regular physical activity and different dietary approaches may alleviate fatigue and pain.

Extreme phenotypic heterogeneity in non-expansion spinocerebellar ataxias

Although the best-known spinocerebellar ataxias (SCAs) are triplet repeat diseases, many SCAs are not caused by repeat expansions. The rarity of individual non-expansion SCAs, however, has made it difficult to discern genotype-phenotype correlations. We therefore screened individuals who had been found to bear variants in a non-expansion SCA-associated gene through genetic testing, and after we eliminated genetic groups that had fewer than 30 subjects, there were 756 subjects bearing single-nucleotide variants or deletions in one of seven genes: CACNA1A (239 subjects), PRKCG (175), AFG3L2 (101), ITPR1 (91), STUB1 (77), SPTBN2 (39), or KCNC3 (34). We compared age at onset, disease features, and progression by gene and variant. There were no features that reliably distinguished one of these SCAs from another, and several genes-CACNA1A, ITPR1, SPTBN2, and KCNC3-were associated with both adult-onset and infantile-onset forms of disease, which also differed in presentation. Nevertheless, progression was overall very slow, and STUB1-associated disease was the fastest. Several variants in CACNA1A showed particularly wide ranges in age at onset: one variant produced anything from infantile developmental delay to ataxia onset at 64 years of age within the same family. For CACNA1A, ITPR1, and SPTBN2, the type of variant and charge change on the protein greatly affected the phenotype, defying pathogenicity prediction algorithms. Even with next-generation sequencing, accurate diagnosis requires dialogue between the clinician and the geneticist.

The perception of disability in cerebral palsy: a cross-sectional study using the WHODAS 2.0

This observational study aims to describe the level of perceived disability in Cerebral Palsy (CP). We described the perception of adults by using the interviewer-administered version of the WHO disability assessment schedule (WHODAS 2.0). In case of intellectual disability (ID), the proxy-administered version was used, and a caregiver was asked to report the difficulties experienced by the patient; 199 patients were enrolled. The level of perceived disability was higher when referred to patients with ID (proxy report) than when referred to patients without ID (p < .001). For all patients, the level of perceived disability varied depending on the severity and the localization of motor impairment (both p < .001). No differences were observed based on the type of motor impairment. The perceived disability was correlated with age only for patients with no ID (p < .05). The WHODAS 2.0 may be a useful tool to explore the perception of disability in CP.

Automated ICF Coding of Rehabilitation Notes for Low-Resource Languages via Continual Training of Language Models

The coding of medical documents and in particular of rehabilitation notes using the International Classification of Functioning, Disability and Health (ICF) is a difficult task showing low agreement among experts. Such difficulty is mainly caused by the specific terminology that needs to be used for the task. In this paper, we address the task developing a model based on a large language model, BERT. By leveraging continual training of such a model using ICF textual descriptions, we are able to effectively encode rehabilitation notes expressed in Italian, an under-resourced language.

The perceived impact of Covid-19 pandemic on the children with cerebral palsy: the parents' perspective explored within the "6-F words" framework

BACKGROUND

In 2020 the world faced the spread of the coronavirus infection disease (Covid-19). This was a general public health emergency but many people with disabilities might have been particularly affected.

OBJECTIVE

This paper aims to investigate the impact of the Covid-19 pandemic on children with Cerebral Palsy (CP) and their families.

METHODS

110 parents of children with CP (aged 2 to 19) who completed a questionnaire were included. These children were under the care of one of the Italian Children Rehabilitation Centers. Socio-demographic and clinical information about patients and their families were collected. In addition, difficulties on adopting protective measures and in respecting lockdown rules by children were explored. We adopted the ICF (International Classification of Functioning, Disability and Health) framework to create multiple choice questions. Descriptive statistics were reported and logistic regression analyses were run in order to identify the predictors of perceived impairment in motor, speech, manual and behavioral abilities.

RESULTS

Daily activities of children, as well as rehabilitation and fitness sessions, underwent a change during the pandemic. Spending more time with family due to lockdown measures, has had, in some cases a positive effect however there was a perceived decrease in rehabilitation support and school activities. The age range (between 7 and 12 years) and difficulty in respecting rules emerged as significant predictors of the perceived impairment due to Covid-19 pandemic.

CONCLUSIONS

The pandemic has had different impacts on children and their families on the basis of children's characteristics. Rehabilitation activities during a hypothetic lockdown should consider these characteristics.

Case report: A novel FARS2 deletion and a missense variant in a child with complicated, rapidly progressive spastic paraplegia

Defects in FARS2 are associated with either epileptic phenotypes or a spastic paraplegia subtype known as SPG77. Here, we describe an 8-year-old patient with severe and complicated spastic paraplegia, carrying a missense variant (p.Pro361Leu) and a novel intragenic deletion in FARS2. Of note, the disease is unexpectedly progressing rapidly and in a biphasic way differently from the previously reported cases. Our study provides the first detailed molecular characterization of a FARS2 deletion and its underlying molecular mechanism, and demonstrates the need for combining different tools to improve the diagnostic rate.

Progressive Spinal Cord Degeneration in Friedreich's Ataxia: Results from ENIGMA-Ataxia

BACKGROUND

Spinal cord damage is a hallmark of Friedreich's ataxia (FRDA), but its progression and clinical correlates remain unclear.

OBJECTIVE

The objective of this study was to perform a characterization of cervical spinal cord structural damage in a large multisite FRDA cohort.

METHODS

We performed a cross-sectional analysis of cervical spinal cord (C1-C4) cross-sectional area (CSA) and eccentricity using magnetic resonance imaging data from eight sites within the ENIGMA-Ataxia initiative, including 256 individuals with FRDA and 223 age- and sex-matched control subjects. Correlations and subgroup analyses within the FRDA cohort were undertaken based on disease duration, ataxia severity, and onset age.

RESULTS

Individuals with FRDA, relative to control subjects, had significantly reduced CSA at all examined levels, with large effect sizes (d > 2.1) and significant correlations with disease severity (r < -0.4). Similarly, we found significantly increased eccentricity (d > 1.2), but without significant clinical correlations. Subgroup analyses showed that CSA and eccentricity are abnormal at all disease stages. However, although CSA appears to decrease progressively, eccentricity remains stable over time.

CONCLUSIONS

Previous research has shown that increased eccentricity reflects dorsal column (DC) damage, while decreased CSA reflects either DC or corticospinal tract (CST) damage, or both. Hence our data support the hypothesis that damage to the DC and damage to CST follow distinct courses in FRDA: developmental abnormalities likely define the DC, while CST alterations may be both developmental and degenerative. These results provide new insights about FRDA pathogenesis and indicate that CSA of the cervical spinal cord should be investigated further as a potential biomarker of disease progression. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Muscle MRI in McArdle Disease: A European Multicenter Observational Study

BACKGROUND AND OBJECTIVES

Glycogen storage disease type V (GSDV) or McArdle disease is a muscle glycogenosis that classically manifests with exercise intolerance and exercise-induced muscle pain. Muscle weakness and wasting may occur, but it is typically mild and described as located around the shoulder girdle in elderly patients. Paraspinal muscle involvement has received little attention in the literature. This study aimed to quantify fat replacement of paraspinal, shoulder, and lower limb muscles by magnetic resonance imaging in a European cohort of patients with GSDV.

METHODS

This observational study included patients with verified GSDV and healthy controls (HCs). Whole-body MRIs and clinical data were collected. The degree of muscle fat replacement was evaluated on T1-weighted images with the semiquantitative visual Mercuri scale and on Dixon images where individual muscle fat fractions (FFs) were quantitatively calculated.

RESULTS

MRIs and clinical data from a total of 57 patients with GSDV (age 44.3 ± 15.2 years) from 5 European centers were assessed and compared with findings in 30 HCs (age 42.4 ± 14.8 years). Patients with GSDV had significantly more fat replacement of the paraspinal muscles compared with HCs on all levels investigated, detected by both the Mercuri and the Dixon method (Dixon, paraspinal composite FF [GSDV vs HC] at the cervical level: 31.3 ± 13.1 vs 15.4 ± 7.8; thoracic level: 34.5±19.0 vs 16.9±8.6; and lumbar level: 43.9 ± 19.6 vs 21.8 ± 10.2 [p < 0.0001]). Patients with GSDV also had significantly more fat replacement of the shoulder muscles (evaluated by the Mercuri scale), along with significantly, but numerically less, fat replacement of thigh and calf muscles compared with HC (Dixon, lower limb composite FF [GSDV vs HC] at the thigh level: 12.0 ± 5.6 vs 8.8 ± 2.7 and calf level: 13.1 ± 6.7 vs 9.1 ± 2.9 [p ≤ 0.05]).

DISCUSSION

The primary findings are that patients with GSDV exhibit severe fat replacement of the paraspinal muscles, which can have important implications for the future management of patients with GSDV, and also significant fat replacement of shoulder girdle muscles as previously described. The clinical relevance of the discrete increases in lower limb FF is uncertain. The changes were found to be age-related in both groups, but an accelerated effect was found in GSDV, probably due to continuous muscle damage.

Psychiatric symptoms in adult patients with cerebral palsy: A cohort study

Background

Patients with cerebral palsy (CP) have an increased risk of developing mental health disorders.

Aims

This paper is aimed to investigate the occurrence of psychiatric symptoms in adults with CP and to explore the relation between clinical and psychosocial variables.

Methods and procedures

We included 199 adults with a diagnosis of CP. The chi-square and the Mann-Whitney U tests were used to compare clinical and psychosocial variables, the level of perceived disability, and the type of observed parental style in patients with and without psychiatric symptoms. Logistic regression analysis was used to identify variables that could predict the occurrence of mental health disorders.

Outcome and results

Anxiety and psychosis were the most represented disorders. Age, living status, assumption of drugs, motor, manual, and global impairment were significantly different between patients with and without psychiatric symptoms. Similarly, a different parental style was observed between the two groups. Logistic regression indicated that living status, prescribed drugs, parental style, and the perceived disability in getting along with others predicted the occurrence of psychiatric symptoms.

Conclusions and implications

Results suggest that patients with and without psychiatric symptoms have different clinical and psychosocial characteristics. Some variables should be considered as potentially affecting the mental health of patients with CP.

20 Years of ICF-International Classification of Functioning, Disability and Health: Uses and Applications around the World

The International Classification of Functioning Disability and Health (ICF) was approved in 2001 and, since then, several studies reported the increased interest about its use in different sectors. A recent overview that summarizes its applications is lacking. This study aims to provide an updated overview about 20 years of ICF application through an international online questionnaire, developed by the byline authors, and sent to each World Health Organization Collaborating Centers of the Family of International Classifications (WHO-FIC CCs). Data was collected during October 2020 and December 2021 and descriptive content analyses were used to report main results. Results show how, in most of the respondent countries represented by WHO-FIC CCs, ICF was mainly used in clinical practice, policy development and social policy, and in education areas. Despite its applications in different sectors, ICF use is not mandatory in most countries but, where used, it provides a biopsychosocial framework for policy development in health, functioning and disability. The study provides information about the needs related to ICF applications, that can be useful to organize targeted intervention plans. Furthermore, this survey methodology can be re-proposed periodically to monitor the use of the ICF in the future.

Respiratory Function in Friedreich’s Ataxia

Background: Friedreich’s ataxia is an inherited, rare, progressive disorder of children and young adults. It is characterized by ataxia, loss of gait, scoliosis, cardiomyopathy, dysarthria and dysphagia, with reduced life expectancy. Alterations of respiratory dynamics and parameters are frequently observed. However, in the literature there are few, dated studies with small cohorts. Our study aims to make an objective analysis of the respiratory condition of both early and late stage FRDA patients, looking for correlations with the motor, skeletal, speech and genetic aspects of this condition. Materials and methods: This retrospective observational study is based on the collection of clinical and instrumental respiratory data of 44 subjects between 13 and 51 years attending a tertiary rehabilitation centre in northern Italy. The analysis was carried out using Pearson’s correlation test, ANOVA test and post hoc tests. Results: Data show the presence of a recurrent pattern of respiratory dysfunction of a restrictive type, with reduction in forced vital capacity and of flow and pressure parameters. The severity of the respiratory condition correlates with the disease severity (measured with disease-specific scales), with pneumophonic alterations and with the severity of the thoracic scoliotic curve. Conclusions: Respiratory function is impaired at various degrees in FRDA. The complex condition of inco-ordination and hyposthenia in FRDA affects daytime and night-time respiratory efficiency. We believe that the respiratory deficit and the inefficiency of cough are indeed a clinical problem deserving consideration, especially in the context of the concomitant postural difficulty and the possible presence of dysphagia. Therefore, the rehabilitation project for the subject with FRDA should also consider the respiratory function.

Clinical-Genetic Features Influencing Disability in Spastic Paraplegia Type 4

Background and Objectives

Hereditary spastic paraplegias (HSPs) are a group of inherited rare neurologic disorders characterized by length-dependent degeneration of the corticospinal tracts and dorsal columns, whose prominent clinical feature is represented by spastic gait. Spastic paraplegia type 4 (SPG4, SPAST-HSP) is the most common form. We present both clinical and molecular findings of a large cohort of patients, with the aim of (1) defining the clinical spectrum of SPAST-HSP in Italy; (2) describing their molecular features; and (3) assessing genotype-phenotype correlations to identify features associated with worse disability.

Methods

A cross-sectional retrospective study with molecular and clinical data collected in an anonymized database was performed.

Results

A total of 723 Italian patients with SPAST-HSP (58% men) from 316 families, with a median age at onset of 35 years, were included. Penetrance was 97.8%, with men showing higher Spastic Paraplegia Rating Scale (SPRS) scores (19.67 ± 12.58 vs 16.15 ± 12.61, p = 0.009). In 26.6% of patients with SPAST-HSP, we observed a complicated phenotype, mainly including intellectual disability (8%), polyneuropathy (6.7%), and cognitive decline (6.5%). Late-onset cases seemed to progress more rapidly, and patients with a longer disease course displayed a more severe neurologic disability, with higher SPATAX (3.61 ± 1.46 vs 2.71 ± 1.20, p < 0.001) and SPRS scores (22.63 ± 11.81 vs 12.40 ± 8.83, p < 0.001). Overall, 186 different variants in the SPAST gene were recorded, of which 48 were novel. Patients with SPAST-HSP harboring missense variants displayed intellectual disability (14.5% vs 4.4%, p < 0.001) more frequently, whereas patients with truncating variants presented more commonly cognitive decline (9.7% vs 2.6%, p = 0.001), cerebral atrophy (11.2% vs 3.4%, p = 0.003), lower limb spasticity (61.5% vs 44.5%), urinary symptoms (50.0% vs 31.3%, p < 0.001), and sensorimotor polyneuropathy (11.1% vs 1.1%, p < 0.001). Increasing disease duration (DD) and abnormal motor evoked potentials (MEPs) were also associated with increased likelihood of worse disability (SPATAX score>3).

Discussion

The SPAST-HSP phenotypic spectrum in Italian patients confirms a predominantly pure form of HSP with mild-to-moderate disability in 75% of cases, and slight prevalence of men, who appeared more severely affected. Early-onset cases with intellectual disability were more frequent among patients carrying missense SPAST variants, whereas patients with truncating variants showed a more complicated disease. Both longer DD and altered MEPs are associated with worse disability.

Functional MRI Studies in Friedreich's Ataxia: A Systematic Review

Friedreich's ataxia (FRDA) is an inherited neurodegenerative movement disorder with early onset, widespread cerebral and cerebellar pathology, and no cure still available. Functional MRI (fMRI) studies, although currently limited in number, have provided a better understanding of brain changes in people with FRDA. This systematic review aimed to provide a critical overview of the findings and methodologies of all fMRI studies conducted in genetically confirmed FRDA so far, and to offer recommendations for future study designs. About 12 cross-sectional and longitudinal fMRI studies, included 198 FRDA children and young adult patients and, 205 healthy controls (HCs), according to the inclusion criteria. Details regarding GAA triplet expansion and demographic and clinical severity measures were widely reported. fMRI designs included motor and cognitive task paradigms, and resting-state studies, with widespread changes in functionally activated areas and extensive variability in study methodologies. These studies highlight a mixed picture of both hypoactivation and hyperactivation in different cerebral and cerebellar brain regions depending on fMRI design and cohort characteristics. Functional changes often correlate with clinical variables. In aggregate, the findings provide support for cerebro-cerebellar loop damage and the compensatory mechanism hypothesis. Current literature indicates that fMRI is a valuable tool for gaining in vivo insights into FRDA pathology, but addressing that its limitations would be a key to improving the design, interpretation, and generalizability of studies in the future.

Deep Brain Stimulation in childhood-onset dystonia due to brain pathology. A long-term study

BACKGROUND

Pallidal Deep Brain Stimulation (DBS) is an established treatment option for isolated, inherited or idiopathic dystonia, however data on its safety and efficacy in other forms of dystonia are more limited.

OBJECTIVES

Retrospective analysis of motor and non-motor outcomes in pediatric onset refractory dystonia due to static or progressive brain disorders in a cohort of patients with a DBS treatment duration ≥12 months.

METHODS

Multidisciplinary assessments including standardised scales/tests of motor function, pain, quality of life, cognition and language were carried out before implantation and longitudinally afterwards.

RESULTS

9 patients were included, 7 had cerebral palsy. Mean age at implantation was 209 months ± 156, mean treatment duration 84 ± 37 months. DBS was well tolerated and positively affected both motor and non-motor functions. In particular, statistically significant improvements were documented in Burke-Fahn-Marsden Scale scores (- 19.9% p 0.01031) at 12 months and in long-term quality of life (+28.6%, p 0.0292).

CONCLUSIONS

DBS may be a useful treatment option in generalized dystonia associated with brain pathology. Even when the motor benefits are limited, improvements in quality of life and non-motor functions, or the possible prevention of serious dystonia-related complications, may have a significant impact on overall clinical status.

Multifaceted and Age-Dependent Phenotypes Associated With Biallelic PNPLA6 Gene Variants: Eight Novel Cases and Review of the Literature

A wide spectrum of neurodegenerative diseases has been associated with pathogenic variants in the PNPLA6 (patatin-like phospholipase domain-containing protein 6) gene, including spastic paraplegia type 39, Gordon-Holmes, Boucher-Neuhauser, Oliver-Mc Farlane, and Laurence-Moon syndromes. These syndromes present variable and overlapping clinical symptoms, encompassing cerebellar ataxia, hypogonadotropic hypogonadism, chorioretinal dystrophy, spastic paraplegia, muscle wasting, peripheral neuropathy, and cognitive impairment. In the present study, we performed a wide genetic screening in 292 patients presenting with ataxia or spastic paraplegia using a probe-based customized gene panel, covering >200 genes associated with spinocerebellar diseases. We identified six novel and four recurrent PNPLA6 gene variants in eight patients (2.7%). Six patients presented an infantile or juvenile onset (age <18), and two patients had an adult onset. Cerebellar ataxia was observed in seven patients and spastic paraplegia in one patient. Progression of cerebellar symptoms was slow in all patients, who retained ambulation even after a mean disease duration of 15 years. Brain MRI showed cerebellar atrophy in 6/8 patients, more pronounced in superior and dorsal vermis lobules (I to VII). Additional clinical features included hypogonadotropic hypogonadism (5/8), growth hormone deficiency (2/8), peripheral axonal neuropathy (4/8), cognitive impairment (3/8), chorioretinal dystrophy (2/8), and bilateral vestibular areflexia with a reduced visual vestibule-ocular reflex (1/8). In accordance with previous studies, chorioretinal dystrophy was the most frequent presenting symptom in early onset patients, hypogonadotropic hypogonadism in juvenile onset cases, and cerebellar ataxia in adult patients. One patient had an initial clinical presentation compatible with Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome (CANVAS), but no pathological expansions in the RFC1 gene. In conclusion, patients with PNPLA6 variants present a variable age of onset spanning from infancy to adulthood, and each clinical symptom has an age-dependent manifestation thus requiring a multi-systemic diagnostic approach. The description of patients presenting very late-onset cerebellar ataxia suggests that PNPLA6 genetic screening should also be considered in the diagnostic workout of adult cerebellar ataxia.

Monoallelic KIF1A-related disorders: a multicenter cross sectional study and systematic literature review

BACKGROUND

Monoallelic variants in the KIF1A gene are associated with a large set of clinical phenotypes including neurodevelopmental and neurodegenerative disorders, underpinned by a broad spectrum of central and peripheral nervous system involvement.

METHODS

In a multicenter study conducted in patients presenting spastic gait or complex neurodevelopmental disorders, we analyzed the clinical, genetic and neuroradiological features of 28 index cases harboring heterozygous variants in KIF1A. We conducted a literature systematic review with the aim to comparing our findings with previously reported KIF1A-related phenotypes.

RESULTS

Among 28 patients, we identified nine novel monoallelic variants, and one a copy number variation encompassing KIF1A. Mutations arose de novo in most patients and were prevalently located in the motor domain. Most patients presented features of a continuum ataxia-spasticity spectrum with only five cases showing a prevalently pure spastic phenotype and six presenting congenital ataxias. Seventeen mutations occurred in the motor domain of the Kinesin-1A protein, but location of mutation did not correlate with neurological and imaging presentations. When tested in 15 patients, muscle biopsy showed oxidative metabolism alterations (6 cases), impaired respiratory chain complexes II + III activity (3/6) and low CoQ10 levels (6/9). Ubiquinol supplementation (1gr/die) was used in 6 patients with subjective benefit.

CONCLUSIONS

This study broadened our clinical, genetic, and neuroimaging knowledge of KIF1A-related disorders. Although highly heterogeneous, it seems that manifestations of ataxia-spasticity spectrum disorders seem to occur in most patients. Some patients also present secondary impairment of oxidative metabolism; in this subset, ubiquinol supplementation therapy might be appropriate.

Ontological modeling of the International Classification of Functioning, Disabilities and Health (ICF): Activities&Participation and Environmental Factors components

Background

The International Classification of Functioning, Disability and Health (ICF) is a classification of health and health-related states developed by the World Health Organization (WHO) to provide a standard and unified language to be used as a reference model for the description of health and health-related states. The concept of functioning on which ICF is based is that of a “dynamic interaction between a person’s health condition, environmental factors and personal factors”. This overall model has been translated into a classification covering all the main components of functioning. However, the practical use of ICF has highlighted some formal problems, mainly concerning conceptual clarity and ontological coherence.

Methods

In the present work, we propose an initial ontological formalization of ICF beyond its current status, focusing specifically on the interaction between activities and participation and environmental factors. The formalization has been based on ontology engineering methods to drive goal and scope definition, knowledge acquisition, selection of an upper ontology for mapping, conceptual model definition and evaluation, and finally representation using the Ontology Web Language (OWL).

Results

A conceptual model has been defined in a graphical language that included 202 entities, when possible mapped to the SUMO upper ontology. The conceptual model has been validated against 60 case studies from the literature, plus 6 ad-hoc case studies. The model has been then represented using OWL.

Conclusions

This formalization might provide the basis for a revision of the ICF classification in line with current efforts made by WHO on the International Classification of Diseases and on the International Classification of Health Interventions.