The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND): test development and reliability

Insights into spinal muscular atrophy from molecular biomarkers

Spinal muscular atrophy is a devastating motor neuron disease characterized by severe cases of fatal muscle weakness. It is one of the most common genetic causes of mortality among infants aged less than 2 years. Biomarker research is currently receiving more attention, and new candidate biomarkers are constantly being discovered. This review initially discusses the evaluation methods commonly used in clinical practice while briefly outlining their respective pros and cons. We also describe recent advancements in research and the clinical significance of molecular biomarkers for spinal muscular atrophy, which are classified as either specific or non-specific biomarkers. This review provides new insights into the pathogenesis of spinal muscular atrophy, the mechanism of biomarkers in response to drug-modified therapies, the selection of biomarker candidates, and would promote the development of future research. Furthermore, the successful utilization of biomarkers may facilitate the implementation of gene-targeting treatments for patients with spinal muscular atrophy.

Characteristics of Patients With Spinal Muscular Atrophy Who Have Switched Treatments: A Multi-Center Experience in the United Kingdom

INTRODUCTION/AIMS

The evolving landscape of spinal muscular atrophy (SMA) treatment in the United Kingdom allows patients to switch, with health authority approval, from one treatment to another. This retrospective analysis explores the characteristics of pediatric patients across the United Kingdom who switched between available therapies that included nusinersen, risdiplam, and onasemnogene abeparvovec (OA).

METHODS

Demographic data were collected, along with indicators of disease severity and motor function scores for all pediatric patients registered with the SMA REACH UK database who received nusinersen or risdiplam as initial treatments.

RESULTS

Data were available for 375 patients across 19 sites. In total, 289 patients received nusinersen (of whom 21% switched to risdiplam and 16% to OA), and 86 patients received risdiplam (of whom 5% switched to OA). The top reported reasons for treatment changes were as follows: nusinersen to risdiplam: related to spine complexity (28/52), other difficulties related to administration (23/52); nusinersen to OA: parent preference (19/36), bridging to OA (14/36); risdiplam to OA: parent preference (2/2). After switching, no patients requested to go back to the initial treatment. No patients demonstrated deterioration beyond the expected disease trajectory prior to switching.

DISCUSSION

The availability of treatments in the United Kingdom has fundamentally influenced treatment choices, but deterioration in a treatment was not identified as a factor in switching treatments. Further work will be needed to investigate the long-term trajectory of these patients.

Feeding development in healthy infants: A comparative framework for children with Spinal Muscular Atrophy - The DySMAnorm study

OBJECTIVES

Normative data for swallowing parameters in non-dysphagic, healthy children for instrumental and clinical diagnostics are limited. In children with SMA, where due to the degenerative nature a deterioration in swallowing function in the first months of life is possible despite disease-modifying therapy, regular monitoring is required. The DySMA (Dysphagia in Spinal Muscular Atrophy) is a tool available to assess both physiological feeding development and specific abnormalities in children with SMA. We aimed to generate normative data for the DySMA in a sample of healthy infants to facilitate comparisons with children with SMA.

METHODS

Healthy infants and toddlers aged zero to 24 months were recruited and divided into seven age groups. Two speech-language pathologists assessed the children according to the DySMA study protocol. The data were evaluated descriptively and the inter-rater reliability was calculated.

RESULTS

A total of 92 healthy children were included. The DySMA total score ranged from 21 to 35 and showed excellent inter-rater reliability (ICC = .936; 95 % CI .752 to .984). The maximum score of 35 was first reached from 16 months onwards. Categories representing physiological development showed the most significant age-dependent changes, while no age-related development was observed in categories expressing pathology.

CONCLUSION

The DySMA effectively captures physiological feeding development. A higher total score reflects more comprehensive skills in children, while a lower score indicates a reduced range of abilities. By analyzing the normative sample, this tool makes it possible to represent a deviation from the norm for children with SMA.

A de novo deletion underlying spinal muscular atrophy: implications for carrier testing and genetic counseling

Spinal muscular atrophy (SMA) is an autosomal recessive disease most commonly caused by homozygous deletion of the SMN1 gene. Parents of affected children are typically carriers, with a recurrence risk of 25% for future pregnancies. Their close relatives have up to 50% chance of being carriers. Carriers typically possess a single copy of the SMN1 gene; however, some parents carry two copies of SMN1. Current standard diagnostic carrier tests are unable to distinguish between silent carriers with two copies on one chromosome (2 + 0 genotype) and non-carriers (1 + 1 genotype), where a de novo deletion occurred. This distinction is crucial for recurrence risk assessment, which highlights the unsolved challenge to carrier testing and genetic counseling. We combined microsatellite marker analysis, SMN copy number analysis, Sanger sequencing, long-read sequencing and de novo assembly to investigate the cause of the absence of SMN1 in a pedigree with an SMA patient identified through newborn screening, whose parents each carried two SMN1 copies. Our analysis revealed that the father is a silent carrier, while de novo assembly of the SMN locus showed a 1.4 megabase (Mb) de novo deletion between mother and child. This deletion encompasses SMN1 and SMN2 and represents the first reported nucleotide-level resolved SMA-causing deletion to date. Our findings allowed informed counseling of at-risk relatives and illustrate the complexity of SMA carrier testing and counseling. This case underscores the feasibility of and need for advanced genetic testing for SMA carriership in select cases, to improve genetic counseling practices, risk assessment, and family planning.

Cerebrospinal fluid biomarkers of efficacy in patients affected by spinal muscular atrophy type 1 treated with nusinersen

BACKGROUND

The advent of new therapies, such as the antisense oligonucleotide nusinersen, has significantly improved the natural course of spinal muscular atrophy (SMA). Tau proteins and neurofilaments are well known markers of neuro-axonal damages. The neurofilament light protein (NfL) has been proposed as a possible biomarker in SMA. This study aimed to investigate the role of total-tau (t-tau), phosphorylated tau at 181 sites (p-tau 181), NfL, and phosphorylated neurofilament heavy chain (pNfH) proteins as potential cerebrospinal fluid (CSF) biomarkers of disease severity and/or nusinersen treatment response in 14 SMA type 1 patients with a wide age range (2-156 months).

METHODS AND RESULTS

Motor functions were assessed using the "Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders" (CHOP-INTEND) scale at baseline, six months and ten months after treatment. Eight out of 14 patients showed motor improvement. At baseline CSF t-tau and p-tau181 concentration showed a significant negative correlation with age (p = 0.0002 and p = 0.0054 respectively) and a positive correlation with the CHOP-INTEND score (p = 0.0075 and p = 0.0342, respectively). After treatment the tau biomarkers did not show any change, whereas NfL and pNfH concentration significantly decreased (p = 0.0001). The NfL concentration decline correlated to age at baseline (p < 0.05) and to the improvement of the CHOP-INTEND motor score, in the subgroup of patients with a functional improvement above 3 points (p < 0.05).

CONCLUSIONS

CSF neurofilaments and particularly NfL may bepromising biomarkers for monitoring treatment response to nusinersen, both in younger and older patients with severe SMA.

High Expression of SMN circ4-2b-3 in SMA I Children Treated with Nusinersen is Associated with Improved Motor Outcomes

Spinal muscular atrophy (SMA) is a neuromuscular disorder resulting in the loss of α-motor neurons. Nusinersen is an antisense oligonucleotide administered intrathecally to SMA patients that corrects the splicing defect of SMN2. Not all SMA patients respond equally to the therapy and work is in progress to identify biomarkers that may help stratify to SMA patients. In this study, we evaluated the expression of SMN circular RNAs (circRNAs) as potential biomarkers of the disease. This monocentric study was conducted at Fondazione Policlinico A. Gemelli in collaboration with Catholic University of Sacred Heart between December 2019 and March 2023. The inclusion criteria comprised having a diagnosis of SMA I and being treated with Nusinersen. The quantitative analysis of SMN circ4-2b-3 was conducted analyzing patients' serum-derived exosomes. The study included 19 type I SMA patients. Among several SMN circRNAs expressed in SMA cells, only SMN circ4-2b-3 was also detected in exosomes isolated from both type I SMA cell lines and patient-derived serum. High copy number of SMN circ4-2b-3 occurred in a small subgroup of type I SMA patients who were defined as super-responders, based on their response to the Nusinersen therapy. The levels of this circRNA remained high over time. Our results suggest that SMN circ4-2b-3 is a potential biomarker to predict the therapeutic response of type I SMA patients to Nusinersen. However, since other super-responders had a lower number of SMN circ4-2b-3 copies, these findings should be confirmed in larger cohorts.

Rehabilitation improves the effectiveness of nusinersen in children with type 2 spinal muscular atrophy: pNF-H and muscle MRI as potential biomarkers

Introduction

Rehabilitation therapy is an important approach for spinal muscular atrophy (SMA) management. Currently, rare articles introduce that the combination of nusinersen and rehabilitation yields better results in SMA patients compared to using nusinersen alone. The present study examined whether rehabilitation therapy can improve the effectiveness of nusinersen and phosphorylated neurofilament heavy chain (pNF-H) and muscle magnetic resonance imaging (MRI) can serve as potential biomarkers for evaluating the therapeutic effects in type-2 SMA patients.

Methods

This observational study enrolled 22 pediatric patients with type-2 SMA. Enrolled patients were divided into two groups based on the rehabilitation treatment. Motor function and swallowing function were analyzed at baseline, 6, 10, and 14 months. The level of pNF-H and MRI of the thigh skeletal muscles were analyzed at baseline and 14 months.

Results

Greater improvement in motor function was observed in the rehabilitation group compared with the non-rehabilitation group. The levels of pNF-H in the serum and cerebrospinal fluid significantly decreased at 14 months. One patient from the rehabilitation treatment group showed mild improvement in the degree of fatty infiltration in the quadriceps muscles after 14 months.

Conclusion

This study suggests that rehabilitation therapy improves the effectiveness of nusinersen on type-2 SMA patients, and the levels of pNF-H and skeletal muscle MRI can serve as potential biomarkers for evaluating the effectiveness of SMA treatment.

Dysregulated balance of D- and L-amino acids modulating glutamatergic neurotransmission in severe spinal muscular atrophy

Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by reduced expression of the survival motor neuron (SMN) protein. In addition to motor neuron survival, SMN deficiency affects the integrity and function of afferent synapses that provide glutamatergic excitatory drive essential for motor neuron firing and muscle contraction. However, it is unknown whether deficits in the metabolism of excitatory amino acids and their precursors contribute to neuronal dysfunction in SMA. To address this issue, we measured the levels of the main neuroactive D- and L-amino acids acting on glutamatergic receptors in the central nervous system of SMN∆7 mice as well as the cerebrospinal fluid (CSF) of SMA patients of varying severity before and after treatment with the SMN-inducing drug Nusinersen. Our findings reveal that SMN deficiency is associated with disruption of glutamate and serine metabolism in the CSF of severe SMA patients, including decreased concentration of L-glutamate, which is partially corrected by Nusinersen therapy. Moreover, we identify dysregulated l-glutamine/L-glutamate ratio as a shared neurochemical signature of altered glutamatergic synapse metabolism that implicates neuron-astrocyte dysfunction in both severe SMA patients and mouse models. Lastly, consistent with hypo-glutamatergic neurotransmission in SMA, we show that daily supplementation with the NMDA receptor co-agonist d-serine improves neurological deficits in SMN∆7 mice. Altogether, these findings provide direct evidence for central dysregulation of D- and L-amino acid metabolism linked to glutamatergic neurotransmission in severe SMA and have potential implications for treating this neurological disorder.

Assessing disease progression in spinal muscular atrophy, current gaps, and opportunities: a narrative review

Spinal Muscular Atrophy is a genetic disorder causing muscle atrophy and progressive weakness. People living with the condition can have a significant heterogenous phenotype ranging from arrest of motor development to mild impairment. Assessing disease severity has been done using a range of outcome measures that can be classified by body structure or function, by activities or by participation. Functional outocome measures can be generic measures, used to compare individuals or populations against general norms, or disease-specific measures designed to fit disease characteristics. Outcome measures assessing participation are primarily used to capture patients' perceptions of health-related quality of life, daily activity abilities, caregiver burden, and the impact of physical symptoms like fatigue or pain. When assessing disease progression, often the focus on functional abilities has served as an overall indicator of change. With the appearance of disease modifying therapies and the need to evaluate the impact that they had in the course of the disease, new requirements for the existing assessments measure had appeared. The current available toolkit is able to capture a significant spectrum of both, natural history and effect of new treatments but the increased survival, changes in fatigue, bulbar function and others will benefit from further assessment.

Administration practices of and adherence to nusinersen in children with spinal muscular atrophy: a multicenter disease registry study in China

BACKGROUND

Nusinersen was the first approved disease modifying therapy (DMT) for spinal muscular atrophy (SMA). Intrathecal administration of nusinersen enables drug delivery directly to the central nervous system, where the motor neurons are located. Per the package insert, individuals with SMA receive 4 loading doses of nusinersen followed by maintenance doses every 4 months thereafter. The aim of this analysis was to investigate the administration practices of and adherence to nusinersen in Chinese children with SMA.

METHODS

Data were analyzed from a longitudinal, multicenter registry enrolling children with 5q-SMA in China. Information on nusinersen administration, including administration date, care setting, use of sedation and general anesthesia, method of administration, and use of imaging guidance before administration, was collected both retrospectively and prospectively. Adherence rate was calculated at dose and participant level. A dose was considered adherent if the inter-dose interval (for dose-level) and interval from the first dose (for participant-level) followed the standard dosing regimen, with a grace period of ± 7 days for Dose 2 to 4 and ± 28 days thereafter.

RESULTS

A total of 385 participants receiving nusinersen with a total of 2,415 doses were included in the study. The median (interquartile range) number of doses administered per participant was 6 (5-7). Over 99% of intrathecal injections were given in an inpatient setting. Only a few (n = 3, 0.1%) required general anesthesia, while 9% (n = 217) of doses were administered under the use of sedation. Interlaminar lumbar puncture (n = 2,407, 99.7%) was the most common method of administration, followed by cervical puncture (n = 5, 0.2%) and transforaminal lumbar puncture (n = 3, 0.1%). Over 90% of injections did not utilize any imaging guidance prior to administration, with ultrasound (n = 142, 5.9%) being the most commonly used imaging guidance. The adherence rate was 95.7% (1,943/2,030) at dose level and 81.0% (312/385) at participant level. The median inter-dose intervals aligned well with the dosing schedule, with 14 days for Doses 2 and 3, 35 days for Dose 4, and 114-124 days for maintenance doses thereafter.

CONCLUSIONS

Findings from the analysis demonstrated high real-world adherence to nusinersen in Chinese children with SMA.

Systematic literature review of the impact of spinal muscular atrophy therapies on bulbar function

BACKGROUND

Improvement and maintenance of bulbar function are important goals of disease-modifying treatments (DMTs) for spinal muscular atrophy (SMA), but standardized and validated measures for assessing bulbar function do not exist, nor does a widely accepted definition of bulbar function in SMA. As such, the impact of DMTs on bulbar function has not yet been comprehensively evaluated.

OBJECTIVE

We conducted a systematic literature review (SLR) to identify evidence about the impact of DMTs for SMA on bulbar function.

METHODS

We used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines to conduct this review. Embase® and MEDLINE® databases were searched through August 10, 2023. Eligible studies included patients with SMA who were treated with any DMT and reported bulbar function outcomes. Non-English studies were excluded.

RESULTS

We identified 51 studies (across 83 publications) that evaluated SMA DMTs and bulbar function for more than 1600 patients. The ability to feed orally, the ability to tolerate liquids, and the need for nutrition support were commonly reported. Most infants treated with any DMT before SMA symptom onset preserved bulbar function. Infants, children, and adults treated after SMA symptom onset experienced variable results in terms of bulbar function outcomes.

CONCLUSIONS

The definition and assessment of bulbar function are not standardized. Therefore, the tools, scales, methods, and timing used for bulbar function assessments varied among studies. Larger prospective studies using standardized and age-based assessments with longer follow-up periods are needed to assess the clinical stability of bulbar function for patients with SMA who receive DMTs.

Transitioning From Nusinersen to Risdiplam for Spinal Muscular Atrophy in Clinical Practice: A Single-Center Experience

BACKGROUND

Nusinersen and risdiplam are U.S. Food and Drug Administration (FDA)-approved treatments for spinal muscular atrophy (SMA). No head-to-head clinical trials to assess efficacy exist. Observational studies are needed to determine if transitioning to risdiplam is safe and efficacious.

METHODS

This retrospective study at Nationwide Children's Hospital included individuals with SMA treated with nusinersen who switched to risdiplam. Motor, pulmonary and bulbar function were assessed before and 2 years after nusinersen and risdiplam initiation.

RESULTS

Forty-four individuals were included: 11 with SMA type 1, 25 with SMA type 2 and 8 with SMA type 3. Motor function improved after initiation of nusinersen treatment with the most significant improvements seen in the first year. After transition to risdiplam, motor function remained largely stable. Need for noninvasive ventilation (NIV) overnight occurred in both groups. Cough peak flow significantly improved in the risdiplam group. Hospitalizations were the same in both groups. One individual in the nusinersen group gained the ability to take some food by mouth; two individuals in the risdiplam group achieved some oral feeding and two became exclusively orally fed.

CONCLUSIONS

As expected, motor function was most improved in treatment naïve individuals in the first year after nusinersen initiation. Over half of our study population had posterior spinal fusion surgery (57%) which significantly impacted motor and respiratory outcomes, though slightly less so in the risdiplam group. Overall, our data demonstrates that transitioning from nusinersen to risdiplam is associated with a favorable safety profile and stable motor outcomes.

Multi-omics profiling in spinal muscular atrophy (SMA): investigating lipid and metabolic alterations through longitudinal CSF analysis of Nusinersen-treated patients

Spinal muscular atrophy (SMA) is a rare neuromuscular disease caused by biallelic mutations in the SMN1 gene, leading to progressive muscle weakness due to degeneration of the anterior horn cells. Since 2017, SMA patients can be treated with the anti-sense oligonucleotide Nusinersen, which promotes alternative splicing of the SMN2 gene, by regular intrathecal injections. In this prospective study, we applied metabolomic, lipidomic, and proteomic analysis to examine sequential CSF samples from 13 SMA patients and controls. This multi-omic approach identified over 800 proteins and 400 small molecules including lipids. Multivariate analysis of multi-omic data successfully discriminated between the CSF derived from SMA patients and control subjects. Lipidomic analysis revealed increased levels of cholesteryl esters and lyso-phospholipids, along with reduced levels of cholesterol and phospholipids in the CSF of SMA patients as compared to healthy controls. These data, combined with results from functional assays, led us to conclude that SMA patients exhibit altered levels and function of high-density-lipoprotein (HDL)-like particles in the CSF. Notably, Nusinersen therapy was observed to reverse disease-specific profile changes toward a physiological state, potentially explicable by restoring HDL function.

Experience of nusinersen treatment in advanced spinal muscular atrophy type 1: Characteristics of late responders with delayed treatment efficacy

OBJECTIVE

Little clinical data is available for advanced cases of spinal muscular atrophy (SMA) type 1, particularly those requiring ventilation support. Therefore, this study aimed to evaluate the effectiveness of nusinersen treatment on motor and respiratory function in advanced cases of SMA type 1.

METHODS

This observational cohort study included seven patients with advanced SMA type 1, requiring permanent ventilator support and tracheostomy, at Hyogo Medical University School of Medicine Hospital between July 2017 and July 2019. The primary outcome was change in motor function, assessed using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) score. Subjective changes, which could not be measured with CHOP-INTEND, were also evaluated. The secondary outcomes included changes in respiratory function, measured by tidal volume (TV) and transcutaneous carbon dioxide (TcCO2) levels.

RESULTS

Two patients showed a meaningful improvement in CHOP-INTEND scores (an increase of 4 points) after 2-3 years of nusinersen treatment. The remaining five showed changes ranging from 0 to 2 points. Subjective changes were observed in all patients. Patient respiratory function outcomes varied; TV increased in two patients and decreased in five, and TcCO2 levels decreased in three patients and increased in four.

CONCLUSIONS

Nusinersen may provide meaningful improvement in motor function in some patients with advanced SMA type 1; however, treatment response may take a while and varies between individuals. Further research is needed to substantiate these findings and identify potential prognostic factors for nusinersen treatment.

Safety and Efficacy of Nusinersen Focusing on Renal and Hematological Parameters in Spinal Muscular Atrophy

BACKGROUND

Spinal muscular atrophy (SMA) is a motor neuron disease caused by mutations in the SMN1 gene. Nusinersen, an antisense oligonucleotide, has been shown to improve motor function in SMA patients. However, concerns regarding its renal safety remain as previous studies have linked similar treatments to renal toxicity.

OBJECTIVE

The aim of this study was to evaluate the effects of the nusinersen treatment on platelet counts and renal functions, specifically urine protein excretion, in SMA patients and to estimate safe urinary protein levels before administration of each intrathecal injection.

METHODS

This retrospective study examined data from 33 patients with SMA to assess the effects of nusinersen on motor functions and laboratory parameters including platelet count, serum creatinine, urine protein, and urine creatinine. Measurements were taken at baseline andprior to each maintenance dose, after the completion of four initial loading doses. The baseline values were compared between SMA Type 1 and Type 2 patients, while the changes in these values over time were analyzed within each group.

RESULTS

No significant adverse effects on platelet counts or renal functions were observed. Urine creatinine and protein levels were significantly higher in SMA Type 2 patients compared to SMA Type 1 at baseline; these parameters remained stable in SMA Type 2 but increased significantly after the loading doses in SMA Type 1. Motor function improvements were observed in both groups, with the most significant gains in SMA Type 1 after the loading doses. Thus, improvement in motor functions was associated with increase in urine creatinine.

CONCLUSION

Nusinersen treatment did not cause significant renal toxicity or affect platelet counts. Urine creatinine levels may serve as a potential biomarker for assessing treatment response in SMA Type 1.

Outcomes of early-treated infants with spinal muscular atrophy: A multicenter, retrospective cohort study

INTRODUCTION/AIMS

While prompt identification and treatment of infants with spinal muscular atrophy (SMA) can ameliorate outcomes, variability persists. This study assessed management and outcomes of early-treated infants with SMA.

METHODS

We analyzed retrospective data at 12 centers on infants with SMA treated at age ≤6 weeks from August 2018 to December 2023.

RESULTS

Sixty-six patients, 35 with two SMN2 copies and 31 with ≥3 SMN2 copies, were included. Twenty-five (38%, 22 with two SMN2 copies), had SMA findings before initial treatment which was onasemnogene abeparvovec in 47 (71%) and nusinersen in 19 (29%). Thirty-two received sequential or combination treatments, including 16 adding nusinersen or risdiplam due to SMA findings following onasemnogene abeparvovec. All sat independently. Compared to children with ≥3 SMN2 copies, those with two SMN2 copies were less likely to walk (23/34 [68%] vs. 31/31 [100%], p < .001) and less likely to walk on time (9/34 [26%] vs. 29/31 [94%], p < .001); one non-ambulatory child was <18 months old and was excluded from this analysis. No patients required permanent ventilation or exclusively enteral nutrition; six required nocturnal non-invasive ventilation and four utilized supplemental enteral nutrition, all with two SMN2 copies.

DISCUSSION

Early treatment of infants with SMA can improve outcomes as indicated by our cohort, all of whom sat independently and are without permanent ventilation. However, our study demonstrates ongoing disability in most children with two SMN2 copies despite early monotherapy and emphasizes the need for additional research, including earlier monotherapy, initial combination therapy, prenatal treatment, and non-SMN modifying treatments.

Case Report: Atypical motor development in a patient with the mosaic form of Down syndrome and spinal muscular atrophy type 2- long-term observation

A boy is presented in whom Down Syndrome mosaicism and spinal muscular atrophy by overlapping clinical symptoms delayed the diagnosis and caused complicated motor development. The boy from the first pregnancy was delivered vaginally, week 37, Apgar 10, birth weight 3,650 g. The mother, aged 30, had no family history of Down Syndrome or neuromuscular diseases. Primary diagnosis at the age of 3 weeks: unbalanced male karyotype -mos 47, XY+21 [22]/46, XY. At 20 months, the parents observed the disappearance of the high kneeling function and asked for a neurologist's consultation. The neurological examination showed symmetrically reduced muscle tone and symmetrically weakened knee and ankle tendon reflexes. The physiotherapeutic assessment revealed a symmetrical weakening of muscle strength and hand tremor (features characteristic of patients with spinal muscular atrophy). The final diagnosis, set at the age of 27 months, was thus the mosaic form of Down Syndrome and spinal muscular atrophy type 2.

Prognostic factors for tube feeding in type I SMA patients treated with disease-modifying therapies: a cohort study

The aim of this study was to assess the need for tube feeding in a cohort of treated infants with type I SMA and to identify predictive factors. All patients were classified at baseline, when treatment started, and at follow-up according to their functional level and the need for tube feeding. Fisher's exact test was used to examine the associations between the outcome at the last follow-up and SMA type, SMN2 copy number, and baseline nutritional status. ANOVA was performed to compare CHOP INTEND scores and age at treatment initiation with outcomes. The cohort includes 75 type I SMA infants treated between 0.1 and 5 years of age. At the last follow-up, 34 had no need for tube feeding, 9 had tube feeding but were also able to be fed by mouth, and 32 had tube feeding and were unable to be fed by mouth. Thirty of the 41 infants with tube feeding at follow-up already had feeding difficulties when treatment was started. The need for tube feeding at follow-up was associated with the level of feeding involvement at baseline and with CHOP INTEND scores [p < 0.001] but not with SMN2 copy number, SMA type 1 subtypes or age at treatment. The results of this study suggest that the need for tube feeding is not frequent in treated infants with type I SMA and, when occurring, can be predicted by the level of feeding involvement and low CHOP INTEND scores at baseline. What is Known: • The advent of disease-modifying therapies is increasingly changing the approach to swallowing and nutritional management in type I SMA. • Clinical trials and real-world data using all three disease-modifying therapies report a rather wide variability of feeding outcome and need for tube feeding that is often related to different cohorts that makes comparison between studies very difficult. What is New: • The real-world findings of this study, including all the children treated since treatments became available, confirmed that the need for tube feeding is not an invariable finding. • The level of feeding involvement at baseline appears to be a reliable prognostic indicator of bulbar outcome. • The results highlight the need for interventional studies with structured Speech and Language Therapist protocols that will help to better understand the extent to which bulbar function can be maintained or regained even in children requiring tube feeding.

Type 1 spinal muscular atrophy treated with nusinersen in Norway, a five-year follow-up

BACKGROUND

New treatments for 5q spinal muscular atrophy (SMA) have led to changes in the disease phenotype. Questions about long-term efficacy, however, persist. We present the results from five-year follow-up of the first ten Norwegian patients with SMA type1 treated with nusinersen.

METHODS

- Ten patients referred to the expanded access program were included. Standardized assessments with Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND), the Hammersmith Infant Neurological Examination (HINE-2), compound muscle action potential (CMAP) examination and cerebrospinal fluid analysis of neurofilament light chain (cNfL) were performed.

RESULT

Age at baseline ranged from three months to 11 years and eight months. Nine patients were alive and continued to receive treatment at 62 months of follow-up. CHOP INTEND scores increased significantly up to 38 months. Any further increase from 38 to 50 months was not statistically significant, and scores remained almost unchanged from 50 to 62 months. HINE-2 scores increased but the difference from baseline never reached statistical significance. The youngest patients showed the best motor outcome. The changes in CMAP scores were not statistically significant. cNfL values were significantly reduced after 18 months compared with baseline; the largest difference occurred between baseline and 6 months. There was a significant negative correlation between log cNfL and CHOP INTEND (p = 0.042). Bulbar and respiratory function did not improve during the observation period.

CONCLUSION

Our findings support previously reported results on efficacy and safety of nusinersen. All patients have shown improvement in motor function. The need of respiratory and nutritional support did not improve.

Gross motor delays in infants and young boys with Duchenne muscular dystrophy

BACKGROUND

Duchenne muscular dystrophy (DMD), an X-linked progressive neurodegenerative disorder, is being added to required universal screening programs for newborns in the United States. It is estimated that this will result in around 880 patients presenting at clinics in infancy. Very little is known about the early gross motor abilities in infants and young boys with DMD.

OBJECTIVE

Describe the early gross motor skill acquisition in boys in our clinic with DMD.

METHODS

Between the years 2016 and 2024, 90 boys with DMD under the age of 6 years (2 months - 5 years 10 months at their first visit) were evaluated as part of their standard of care during regularly scheduled clinic visits using the using the Bayley Scales of Infant & Toddler Development, Third Edition (Bayley-III). Forty-seven boys were seen in clinic longitudinally with two to six follow up visits for a total of 129 assessments.

RESULTS

Ninety four percent of the boys with DMD seen in our clinic demonstrated delays in gross motor skills across the age span when compared with normative controls. None of the boys reached a ceiling on the Bayley-III despite being older than the intended age range of the test.

CONCLUSIONS

Our clinic data showed an almost universal gross motor delay in infants and toddlers that did not diminish over time.

Efficacy of Nusinersen Treatment in Type 1, 2, and 3 Spinal Muscular Atrophy: Real-World Data from a Single-Center Study

BACKGROUND

Spinal muscular atrophy (SMA) is an inherited neuromuscular disease characterized by progressive muscle weakness and atrophy due to the absence of the survival motor neuron 1 (SMN1) gene. SMA is classified into types 0 through 4 based on the age of symptom onset and the severity of motor function decline. Recent advances in SMA treatment, including nusinersen, onasemnogene abeparvovec, and risdiplam, have significantly improved the prognosis of SMA patients. This study evaluated the safety and efficacy of nusinersen in pediatric patients with SMA types 1, 2, and 3 in a real-world clinical setting.

METHODS

This prospective observational single-center study assessed the treatment effects of nusinersen in 23 pediatric patients with genetically confirmed SMA over a 22-month observation period. All the participants received intrathecal loading doses of 12 mg of nusinersen on days 1, 14, 28, and 63, followed by maintenance doses every four months. Functional assessments were conducted using the CHOP-INTEND scale. Data were collected during routine patient visits, including clinical laboratory tests and vital sign parameters, and adverse events were recorded. The inclusion criteria were defined by the national reimbursement program for nusinersen treatment in Poland.

RESULTS

Initially, 37 patients ranging from 1 month old to 18 years old were included, but 23 were ultimately observed due to changes in treatment regimens or assessment scales. The patients showed significantly improved CHOP-INTEND scores over the 22-month period. At 6 months, the average increase was 4.2 points, continuing to 17.8 points at 22 months. By the end of the study, 100% of patients showed either stabilization or improvement, with significant clinical improvements observed in several patients. Nusinersen was generally well-tolerated, with post-lumbar puncture headache and lower back pain being the most common adverse events.

CONCLUSIONS

Nusinersen treatment significantly enhances motor function in pediatric patients with SMA types 1, 2, and 3. This study demonstrates the importance of early and sustained treatment, with most patients showing the continuous improvement or stabilization of motor function. These findings support the use of nusinersen as an effective therapy for SMA; however, further research is needed to understand the long-term outcomes and optimize treatment strategies.

A 5-year natural history study in LAMA2-related muscular dystrophy and SELENON-related myopathy: the Extended LAST STRONG study

BACKGROUND

SELENON-related myopathy (SELENON-RM) is a rare congenital myopathy characterized by slowly progressive axial muscle weakness, rigidity of the spine, scoliosis, and respiratory insufficiency. Laminin-a2-related muscular dystrophy (LAMA2-MD) has a similar clinical phenotype, which ranges from severe, early-onset congenital muscular dystrophy type 1A (MDC1A) to milder forms presenting as childhood- or adult-onset limb-girdle type muscular dystrophy. The first 1.5-year natural history follow-up showed that 90% of the patients had low bone quality, respiratory impairments were found in all SELENON-RM and most of the LAMA2-MD patients, and many had cardiac risk factors. However, further extensive knowledge on long-term natural history data, and clinical and functional outcome measures is needed to reach trial readiness. Therefore, we extended the natural history study with 3- and 5-year follow-up visits (Extended LAST STRONG).

METHODS

The Extended LAST STRONG is a long-term natural history study in Dutch-speaking patients of all ages diagnosed with genetically confirmed SELENON-RM or LAMA2-MD, starting in September 2023. Patients visit our hospital twice over a period of 2 years to complete a 5-year follow up from the initial LAST-STRONG study. At both visits, they undergo standardized neurological examination, hand-held dynamometry (age ≥ 5 years), functional measurements, muscle ultrasound, respiratory assessments (spirometry, maximal inspiratory and expiratory pressure, sniff nasal inspiratory pressure; age ≥ 5 years), Dual-energy X-ray absorptiometry (DEXA-)scan (age ≥ 2 years), X-ray of the left hand (age ≤ 17 years), lower extremity MRI (age ≥ 10 years), accelerometry for 8 days (age ≥ 2 years), and questionnaires (patient report and/or parent proxy; age ≥ 2 years). All examinations are adapted to the patient's age and functional abilities. Disease progression between all subsequent visits and relationships between outcome measures will be assessed.

DISCUSSION

This study will provide valuable insights into the 5-year natural history of patients with SELENON-RM and LAMA2-MD and contribute to further selecting relevant and sensitive to change clinical and functional outcome measures. Furthermore, this data will help optimize natural history data collection in clinical care and help develop clinical care guidelines.

TRIAL REGISTRATION

This study protocol including the patient information and consent forms has been approved by medical ethical reviewing committee ('METC Oost-Nederland'; https://www.ccmo.nl/metcs/erkende-metcs/metc-oost-nederland , file number: 2023-16401). It is registered at ClinicalTrials.gov (NCT06132750; study registration date: 2023-10-05; study first passed date: 2023-11-15).

Dysregulated balance of D- and L-amino acids modulating glutamatergic neurotransmission in severe spinal muscular atrophy

Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by reduced expression of the survival motor neuron (SMN) protein. In addition to motor neuron survival, SMN deficiency affects the integrity and function of afferent synapses that provide glutamatergic excitatory drive essential for motor neuron firing and muscle contraction. However, it is unknown whether deficits in the metabolism of excitatory amino acids and their precursors contribute to neuronal dysfunction in SMA. To address this issue, we measured the levels of the main neuroactive D- and L-amino acids acting on glutamatergic receptors in the central nervous system of SMNΔ7 mice as well as the cerebrospinal fluid (CSF) of SMA patients of varying severity before and after treatment with the SMN-inducing drug Nusinersen. Our findings reveal that SMN deficiency disrupts glutamate and serine metabolism in the CSF of severe SMA patients, including decreased concentration of L-glutamate, which is partially corrected by Nusinersen therapy. Moreover, we identify dysregulated L-glutamine to L-glutamate conversion as a shared neurochemical signature of altered glutamatergic synapse metabolism that implicates astrocyte dysfunction in both severe SMA patients and mouse models. Lastly, consistent with a correlation of higher CSF levels of D-serine with better motor function in severe SMA patients, we show that daily supplementation with the NMDA receptor co-agonist D-serine improves neurological deficits in SMNΔ7 mice. Altogether, these findings provide direct evidence for dysregulation of D- and L-amino acid metabolism linked to glutamatergic neurotransmission in severe SMA and have potential implications for treating this neurological disorder.

Acceptability, validity and responsiveness of inertial measurement units for assessing motor recovery after gene therapy in infants with early onset spinal muscular atrophy: a prospective cohort study

BACKGROUND

Onasemnogene abeparvovec gene replacement therapy (GT) has changed the prognosis of patients with spinal muscular atrophy (SMA) with variable outcome regarding motor development in symptomatic patients. This pilot study evaluates acceptability, validity and clinical relevance of Inertial Measurement Units (IMU) to monitor spontaneous movement recovery in early onset SMA patients after GT.

METHODS

Clinical assessments including CHOPINTEND score (the gold standard motor score for infants with SMA) and IMU measurements were performed before (M0) and repeatedly after GT. Inertial data was recorded during a 25-min spontaneous movement task, the child lying on the back, without (10 min) and with a playset (15 min) wearing IMUs. Two commonly used parameters, norm acceleration 95th centile (||A||_95) and counts per minute (||A||_CPM) were computed for each wrist, elbow and foot sensors.

RESULTS

23 SMA-patients were included (mean age at diagnosis 8 months [min 2, max 20], 19 SMA type 1, three type 2 and one presymptomatic) and 104 IMU-measurements were performed, all well accepted by families and 84/104 with a good child participation (evaluated with Brazelton scale). ||A||_95 and ||A||_CPM showed high internal consistency (without versus with a playset) with interclass correlation coefficient for the wrist sensors of 0.88 and 0.85 respectively and for the foot sensors of 0.93 and 0.91 respectively. ||A||_95 and ||A||_CPM were strongly correlated with CHOPINTEND (r for wrist sensors 0.74 and 0.67 respectively and for foot sensors 0.61 and 0.68 respectively, p-values < 0.001). ||A||_95 for the foot, the wrist, the elbow sensors and ||A||_CPM for the foot, the wrist, the elbow sensors increased significantly between baseline and the 12 months follow-up visit (respective p-values: 0.004, < 0.001, < 0.001, 0.006, < 0.001, < 0.001).

CONCLUSION

IMUs were well accepted, consistent, concurrently valid, responsive and associated with unaided sitting acquisition especially for the elbow sensors. This study is the first reporting a large set of inertial sensor derived data after GT in SMA patients and paves the way for IMU-based follow-up of SMA patients after treatment.

Intersession Intra-Rater and Inter-Rater Reliability of Myotonometer for Upper and Lower Extremity Muscles in Children with Spinal Muscular Atrophy

Background/Objectives: This study aimed to examine intra- and inter-rater reliability of a myotonometer (MyotonPRO) in measuring upper and lower extremity mechanical properties in children with spinal muscular atrophy types I and II. Methods: Biceps brachii, triceps brachii, rectus femoris, and gastrocnemius muscle tone and stiffness in children (n = 21) were measured using the MyotonPRO device. Examiner 1 performed two sets of measurements in 60 min to determine intra-rater reliability. Examiner 2 performed measurements between Examiner 1's sets. Intra-interclass correlation coefficient, minimal detectable change, and standard error of measurement values were calculated to assess intra- and inter-rater reliabilities in this cross-sectional study. Results: The results showed excellent intra- and inter-rater reliability analyses for frequency and stiffness values except for the stiffness value of the gastrocnemius muscle, which presented good reliability (ICC = 0.71). Minimal detectable change values ranged from 0.59 to 1.98 Hz for muscle tone and 16.08 to 124.74 N/m for stiffness (for both intra- and inter-rater reliabilities). Conclusions: Our findings indicate that MyotonPRO is a reliable tool for quantifying upper and lower extremity mechanical properties within one session in children with spinal muscular atrophy types I and II. Mechanical properties of the extremity muscle can be determined using this easily applied tool in future studies.

Profiling neuroinflammatory markers and response to nusinersen in paediatric spinal muscular atrophy

Neuroinflammation is an emerging clinical feature in spinal muscular atrophy (SMA). Characterizing neuroinflammatory cytokines in cerebrospinal fluid (CSF) in SMA and their response to nusinersen is important for identifying new biomarkers and understanding the pathophysiology of SMA. We measured twenty-seven neuroinflammatory markers in CSF from twenty SMA children at different time points, and correlated the findings with motor function improvement. At baseline, MCP-1, IL-7 and IL-8 were significantly increased in SMA1 patients compared to SMA2, and were significantly correlated with disease severity. After six months of nusinersen treatment, CSF levels of eotaxin and MIP-1β were markedly reduced, while IL-2, IL-4 and VEGF-A were increased. The decreases in eotaxin and MIP-1β were associated with changes in motor scores in SMA1. We also detected a transient increase in MCP-1, MDC, MIP-1α, IL-12/IL-23p40 and IL-8 after the first or second injection of nusinersen, followed by a steady return to baseline levels within six months. Our study provides a detailed profile of neuroinflammatory markers in SMA CSF. Our data confirms the potential of MCP-1, eotaxin and MIP-1β as new neuroinflammatory biomarkers in SMA1 and indicates the presence of a subtle inflammatory response to nusinersen during the early phase of treatment.

A reassessment of spinal cord pathology in severe infantile spinal muscular atrophy: Reassessment of spinal cord pathology

AIMS

Spinal muscular atrophy (SMA) is a life-limiting paediatric motor neuron disease characterised by lower motor neuron loss, skeletal muscle atrophy and respiratory failure, if untreated. Revolutionary treatments now extend patient survival. However, a limited understanding of the foundational neuropathology challenges the evaluation of therapeutic success. As opportunities to study treatment-naïve tissue decrease, we have characterised spinal cord pathology in severe infantile SMA using gold-standard techniques, providing a baseline to measure treatment success and therapeutic limitations.

METHODS

Detailed histological analysis, stereology and transmission electron microscopy were applied to post-mortem spinal cord from severe infantile SMA patients to estimate neuron number at the end of life; characterise the morphology of ventral horn, lateral horn and Clarke's column neuron populations; assess cross-sectional spinal cord area; and observe myelinated white matter tracts in the clinically relevant thoracic spinal cord.

RESULTS

Ventral horn neuron loss was substantial in all patients, even the youngest cases. The remaining ventral horn neurons were small with abnormal, occasionally chromatolytic morphology, indicating cellular damage. In addition to ventral horn pathology, Clarke's column sensory-associated neurons displayed morphological features of cellular injury, in contrast to the preserved sympathetic lateral horn neurons. Cellular changes were associated with aberrant development of grey and white matter structures that affected the overall dimensions of the spinal cord.

CONCLUSIONS

We provide robust quantification of the neuronal deficit found at the end of life in SMA spinal cord. We question long-accepted dogmas of SMA pathogenesis and shed new light on SMA neuropathology out with the ventral horn, which must be considered in future therapeutic design.

Onasemnogene abeparvovec gene therapy for spinal muscular atrophy: A cohort study from the United Arab Emirates

INTRODUCTION/AIMS

Spinal muscular atrophy (SMA) manifests with progressive motor neuron degeneration, leading to muscle weakness. Onasemnogene abeparvovec is a US Food and Drug Administration-approved gene replacement therapy for SMA. This study aimed to present short-term data of children in the United Arab Emirates (UAE) treated with onasemnogene abeparvovec, particularly in the context of children requiring invasive ventilatory support via tracheostomy.

METHODS

A retrospective analysis was performed on 60 children who received onasemnogene abeparvovec. All these children received corticosteroids. They were followed up for up to 3 months. Motor function assessments were performed before and after the gene therapy. Comprehensive clinical evaluations, including pulmonary functions, were performed at baseline and the 3-month mark.

RESULTS

Forty-three percent were male, and the mean age at the time of infusion was 29.6 months (SD ± 17.2). The mean weight was 10.1 kg (SD 2.6). All children demonstrated marked improvements in motor function within 3 months of gene therapy administration. No adverse effects attributable to corticosteroid therapy were observed. Positive clinical outcomes, including increased ventilator-free intervals, reduced antibiotic dependency, and fewer hospital admissions, were reported among children with invasive ventilation via tracheostomy.

DISCUSSION

This study demonstrates the favorable tolerability and promising responses to onasemnogene abeparvovec in invasively ventilated pediatric patients. Early improvements in motor function, as observed within 3 months post-treatment, suggest its potential as a viable therapeutic option for this vulnerable patient population.

Proteomics profiling and machine learning in nusinersen-treated patients with spinal muscular atrophy

AIM

The availability of disease-modifying therapies and newborn screening programs for spinal muscular atrophy (SMA) has generated an urgent need for reliable prognostic biomarkers to classify patients according to disease severity. We aim to identify cerebrospinal fluid (CSF) prognostic protein biomarkers in CSF samples of SMA patients collected at baseline (T0), and to describe proteomic profile changes and biological pathways influenced by nusinersen before the sixth nusinersen infusion (T302).

METHODS

In this multicenter retrospective longitudinal study, we employed an untargeted liquid chromatography mass spectrometry (LC-MS)-based proteomic approach on CSF samples collected from 61 SMA patients treated with nusinersen (SMA1 n=19, SMA2 n=19, SMA3 n=23) at T0 at T302. The Random Forest (RF) machine learning algorithm and pathway enrichment analysis were applied for analysis.

RESULTS

The RF algorithm, applied to the protein expression profile of naïve patients, revealed several proteins that could classify the different types of SMA according to their differential abundance at T0. Analysis of changes in proteomic profiles identified a total of 147 differentially expressed proteins after nusinersen treatment in SMA1, 135 in SMA2, and 289 in SMA3. Overall, nusinersen-induced changes on proteomic profile were consistent with i) common effects observed in allSMA types (i.e. regulation of axonogenesis), and ii) disease severity-specific changes, namely regulation of glucose metabolism in SMA1, of coagulation processes in SMA2, and of complement cascade in SMA3.

CONCLUSIONS

This untargeted LC-MS proteomic profiling in the CSF of SMA patients revealed differences in protein expression in naïve patients and showed nusinersen-related modulation in several biological processes after 10 months of treatment. Further confirmatory studies are needed to validate these results in larger number of patients and over abroader timeframe.

Nusinersen effectiveness and safety in pediatric patients with 5q-spinal muscular atrophy: a multi-center disease registry in China

OBJECTIVE

To evaluate the effectiveness and safety of nusinersen for the treatment of 5q-spinal muscular atrophy (SMA) among Chinese pediatric patients.

METHODS

Using a longitudinal, multi-center registry, both prospective and retrospective data were collected from pediatric patients with 5q-SMA receiving nusinersen treatment across 18 centers in China. All patients fulfilling the eligibility criteria were included consecutively. Motor function outcomes were assessed post-treatment by SMA type. Safety profile was evaluated among patients starting nusinersen treatment post-enrollment. Descriptive analyses were used to report baseline characteristics, effectiveness, and safety results.

RESULTS

As of March 2nd, 2023, 385 patients were included. Most patients demonstrated improvements or stability in motor function across all SMA types. Type II patients demonstrated mean changes [95% confidence interval (CI)] of 4.4 (3.4-5.4) and 4.1 (2.8-5.4) in Hammersmith Functional Motor Scale-Expanded (HFMSE), and 2.4 (1.7-3.1) and 2.3 (1.2-3.4) in Revised Upper Limb Module (RULM) scores at months 6 and 10. Type III patients exhibited mean changes (95% CI) of 3.9 (2.5-5.3) and 4.3 (2.6-6.0) in HFMSE, and 2.1 (1.2-3.0) and 1.5 (0.0-3.0) in RULM scores at months 6 and 10. Of the 132 patients, 62.9% experienced adverse events (AEs). Two patients experienced mild AEs (aseptic meningitis and myalgia) considered to be related to nusinersen by the investigator, with no sequelae.

CONCLUSIONS

These data underscore the significance of nusinersen in Chinese pediatric patients with SMA regarding motor function improvement or stability, and support recommendations on nusinersen treatment by Chinese SMA guidelines and continuous coverage of nusinersen by basic medical insurance.

Rehabilitation Strategies for Patients With Spinal Muscular Atrophy in the Era of Disease-Modifying Therapy

The impact of disease-modifying therapy ranges from cure to no impact with a wide range of intermediates. In cases where the intermediate group reaches a plateau after the acquisition of some muscle strength, it is necessary to set a functional level appropriate for increased motor power and establish a long-term exercise plan to maintain it. As the disease status stabilizes and the life span increases, early nonsurgical interventions are required, such as using a standing frame to prevent joint contracture, applying a spinal brace at the early stage of scoliosis, and maintaining sitting postures that exaggerate lumbar lordosis. In cases where scoliosis and hip displacement occur and progress even after conservative managements are implemented, early referral to surgery should be considered. Oromotor activity and swallowing function are influenced not only by the effects of disease-modifying drugs, but also by post-birth experience and training. Therefore, although the feeding tube cannot be removed, it is necessary to make efforts to simulate the infant feeding development while maintaining partial oral feeding. Since the application period of non-invasive ventilators has increased, it has become more important to prevent long-term complications such as facial abrasion, skin allergy, orthodontic deformities, and maxillary flattening caused by the interface. Dual ventilator mode or interface can also be utilized.

Identification of the most relevant aspects of spinal muscular atrophy (SMA) with impact on the quality of life of SMA patients and their caregivers: the PROfuture project, a qualitative study

BACKGROUND

SMA is a hereditary neuromuscular disease that causes progressive muscle weakness and atrophy. Several studies have shown that the burden of SMA is very high at many levels. Functional assessment tools currently used do not completely address the impact of the disease in patients' life. The objective of this qualitative study was to identify aspects of SMA that are relevant to patients and to design items useful for assessment purposes.

RESULTS

Five focus group sessions were run during an annual SMA families meeting in Madrid, Spain. Focus groups were composed by parents of SMA type I children, sitter children type II-III, parents of sitter children type II-III, adult patients, and parents of walker children. Two trained facilitators conducted the focus groups using a semi-structured guideline to cover previously agreed topics based on the input of a Scientific and Patient Advisory Committee. The guideline was adapted for the different groups. According to what was communicated by participants, SMA entails a high burden of disease for both patients and their parents. Burden was perceived in physical, psychological, and social areas. Patient's physical domain was the most relevant for participants, especially for parents of non-ambulant children, followed by limitations of motor scales to capture all changes, parents psychological burden, treatment expectations and patient's psychological burden. Ten domains were the main areas identified as impacted by the disease: mobility and independence, fatigue and fatigability, infections and hospital consultations, scoliosis and contractures, vulnerability, pain, feeding, time spent in care, breathing, and sleep and rest.

CONCLUSIONS

This study confirms the necessity of evaluating other aspects of the disease that are not assessed in the functional motor scale. Measures of other aspects of the disease, such as pain, fatigue, feeding, should be also considered. A patient-reported outcomes instrument measuring such aspects in a valid and reliable way would be very useful. This study generated a list of new items relevant to be systematically measured in the assessment of the impact of SMA on the patients' everyday life.

Exploring the Influence of Concurrent Nutritional Therapy on Children with Spinal Muscular Atrophy Receiving Nusinersen Treatment

Background This study examines spinal muscular atrophy (SMA), a neuromuscular disease associated with malnutrition. Our goals are to assess how effectively screening tools can detect malnutrition and evaluate the impact of nutritional interventions on neurological outcomes, particularly motor functions. Methods Thirty-seven genetically diagnosed SMA patients (types 1, 2, and 3) under nusinersen therapy were included in the study. The nutritional status of these patients was assessed by using anthropometric measurements, including height for age (HFA), weight for height (WFH), and body mass index (BMI) before and after the study. Additionally, the risk of malnutrition was determined using screening tools, namely the Pediatric Yorkhill Malnutrition Score (PYMS) and the Screening Tool for the Assessment of Malnutrition in Pediatrics (STAMP). Nutritional counseling followed the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) guidelines and considered the patients' dietary history, including content and administration method. Motor functions were assessed by validated tests: the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) and the Hammersmith Functional Motor Scale-Expanded (HFMSE). Result The study showed an improvement in HFA, by a change from -0.95 to -0.65 (p = 0.015). Conversely, BMI scores decreased from 0.08 to -0.54 (p = 0.015), while WFH and MUAC showed no significant alterations (p = 0.135, p = 0.307). Following nutritional interventions, HFMSE demonstrated a median increase from 29.5 to 30.5 (p = 0.023). Patients identified as being at high risk for malnutrition based on PYMS and STAMP belonged to the moderate-to-severe malnutrition group (BMI Z-score ≤ -2, p = 0.001). Conclusions Use of screening tools in SMA patients is highly beneficial for the early detection of malnutrition. Future research should highlight the importance of combining nutritional management with nusinersen therapy to potentially alter the disease trajectory, especially in motor and neurological functions.

A Five-Year Review of Newborn Screening for Spinal Muscular Atrophy in the State of Utah: Lessons Learned

Spinal muscular atrophy (SMA) is an autosomal recessive condition characterized by alpha motor neuron degeneration in the spinal cord anterior horn. Clinical symptoms manifest in the first weeks to months of life in the most severe cases, resulting in progressive symmetrical weakness and atrophy of the proximal voluntary muscles. Approximately 95% of SMA patients present with homozygous deletion of the SMN1 gene. With multiple available therapies preventing symptom development and slowing disease progression, newborn screening for SMA is essential to identify at-risk individuals. From 2018 to 2023, a total of 239,844 infants were screened. 13 positive screens were confirmed to have SMA. An additional case was determined to be a false positive. We are not aware of any false-negative cases. All patients were seen promptly, with diagnosis confirmed within 1 week of the initial clinical visit. Patients were treated with nusinersen or onasemnogene abeparvovec. Treated patients with two copies of SMN2 are meeting important developmental milestones inconsistent with the natural history of type 1 SMA. Patients with 3-4 copies of SMN2 follow normal developmental timelines. Newborn screening is an effective tool for the early identification and treatment of patients with SMA. Presymptomatic treatment dramatically shifts the natural history of SMA, with most patients meeting appropriate developmental milestones. Patients with two copies of SMN2 identified through newborn screening constitute a neurogenetic emergency. Due to the complexities of follow-up, a multidisciplinary team, including close communication with the newborn screening program, is required to facilitate timely diagnosis and treatment.

Functional and Structural Changes in Patients with Spinal Muscular Atrophy Treated in Poland during 12-Month Follow-Up: A Prospective Cohort Study

Background: In recent years, rapid advances in diagnosis and treatment have been observed in spinal muscular atrophy (SMA) patients. The introduction of modern therapies and screening tests has significantly changed the clinical picture of the disease. The previous classification has, therefore, been replaced by new phenotypes: non-sitters, sitters, and walkers, defined by the patient's functional level. However, despite the change in the clinical picture of the disease, patients still suffer from accompanying structural disorders such as scoliosis or joint contractures. Their presence also significantly affects the acquisition of subsequent motor skills. Due to this, monitoring structural changes and ensuring therapists are aware of improvements or declines in patient functionality are essential components of clinical practice. This study aims to compare the assessment of structural and functional changes after a 12-month follow-up in SMA patients who have already experienced the effects of the disease and are now receiving modern therapy. Methods: We present a study of 34 SMA patients being treated with modern therapies and tested twice 12 months apart. The participants were tested using structural measurements and validated scales such as The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) and Hammersmith Functional Motor Scale-Expanded (HFMSE). Results: During the 12-month follow-up, patients showed deteriorating, non-statistically significant structural changes. We also proved that patients showed a trend toward functional improvement. Analyzing the individual scale items, we distinguished which participants obtained the maximum score for a given parameter and no longer had an opportunity to improve during the second examination. Conclusions: Our study proved that most patients improved overall motor function. The examination of structural measurements should become a standard in the evaluation of SMA patients.

[Clinical efficacy of nusinersen sodium in the treatment of children with spinal muscular atrophy]

OBJECTIVES

To investigate the efficacy and safety of nusinersen sodium in the treatment of children with spinal muscular atrophy (SMA).

METHODS

A retrospective analysis was conducted on the clinical data of 50 children with 5q SMA who received nusinersen sodium treatment and multidisciplinary treatment management in Shanxi Children's Hospital from February 2022 to February 2024.

RESULTS

Compared with the baseline data, 67% (8/12), 74% (35/47), and 74% (35/47) of the SMA children had a clinically significant improvement in the scores of Philadelphia Infant Test of Neuromuscular Disorders, Hammersmith Functional Motor Scale Expanded, and Revised Upper Limb Module, respectively, and the distance of 6-minute walking test increased from 207.00 (179.00, 281.50) meters to 233.00 (205.25, 287.50) meters (P<0.05) after nusinersen sodium treatment. Of all 50 children with SMA, 24 (48%) showed good tolerability after administration, with no significant or persistent abnormalities observed in 2 034 laboratory test results, and furthermore, there were no serious or immunological adverse events related to the treatment. After treatment, there was a significant change in forced vital capacity as a percentage of the predicted value in 27 children with restrictive ventilatory dysfunction, as well as a significant change in the level of 25-(OH) vitamin D in 15 children with vitamin D deficiency (P<0.05).

CONCLUSIONS

For children with SMA, treatment with nusinersen sodium can continuously improve the response rates of motor function scales, with good tolerability and safety.

Cognitive function in SMA patients with 2 or 3 SMN2 copies treated with SMN-modifying or gene addition therapy during the first year of life

BACKGROUND

Spinal muscular atrophy (SMA) is a neuromuscular disease, causing progressive muscle weakness due to loss of lower motoneurons. Since 2017, three therapies, two modifying gene transcription and one adding the defective gene, have been approved with comparable efficacy on motor outcome. Data on cognitive outcomes of treated SMA type 1 patients is limited. The aim of this study was to evaluate cognitive function in symptomatic and presymptomatic SMA type 1 patients with two or three SMN2 copies who received SMN-modifying or gene-addition therapy in the first year of life.

METHODS

Cognitive testing was performed in 20 patients, including 19 symptomatic SMA type 1 patients with up to three SMN2 copies and 1 pre-symptomatically treated patient. Children were tested using Bayley Scales of Infant Development (BSID-III) at the age of 2 or 3 years or the Wechsler Preschool and Primary Scale of Intelligence (WPSII-IV) at the of age of 5 years.

RESULTS

11/20 patients showed subnormal cognitive development. Boys had significantly lower cognitive scores. Patients requiring assisted ventilation or feeding support were more likely to have cognitive deficits. Achieving more motor milestones was associated with a better cognitive outcome.

CONCLUSION

Treated patients with SMA type 1 have heterogeneous cognitive function with 55 % of patients showing deficits. Risk factors for cognitive impairment in our cohort were male gender and need for assisted ventilation or feeding support. Therefore, cognitive assessment should be included in the standard of care to allow early identification of deficits and potential therapeutic interventions.

Real-world evidence: Risdiplam in a patient with spinal muscular atrophy type I with a novel splicing mutation and one SMN2 copy

Spinal muscular atrophy (SMA), which results from the deletion or/and mutation in the SMN1 gene, is an autosomal recessive neuromuscular disorder that leads to weakness and muscle atrophy. SMN2 is a paralogous gene of SMN1. SMN2 copy number affects the severity of SMA, but its role in patients treated with disease modifying therapies is unclear. The most appropriate individualized treatment for SMA has not yet been determined. Here, we reported a case of SMA type I with normal breathing and swallowing function. We genetically confirmed that this patient had a compound heterozygous variant: one deleted SMN1 allele and a novel splice mutation c.628-3T>G in the retained allele, with one SMN2 copy. Patient-derived sequencing of 4 SMN1 cDNA clones showed that this intronic single transversion mutation results in an alternative exon (e)5 3' splice site, which leads to an additional 2 nucleotides (AG) at the 5' end of e5, thereby explaining why the patient with only one copy of SMN2 had a mild clinical phenotype. Additionally, a minigene assay of wild type and mutant SMN1 in HEK293T cells also demonstrated that this transversion mutation induced e5 skipping. Considering treatment cost and goals of avoiding pain caused by injections and starting treatment as early as possible, risdiplam was prescribed for this patient. However, the patient showed remarkable clinical improvements after treatment with risdiplam for 7 months despite carrying only one copy of SMN2. This study is the first report on the treatment of risdiplam in a patient with one SMN2 copy in a real-world setting. These findings expand the mutation spectrum of SMA and provide accurate genetic counseling information, as well as clarify the molecular mechanism of careful genotype-phenotype correlation of the patient.

Improvement in functional motor scores in patients with non-ambulatory spinal muscle atrophy during Nusinersen treatment in South Korea: a single center study

We analyzed the changes in various motor function scores over a four-year period in patients with non-ambulatory spinal muscular atrophy (SMA) during Nusinersen treatment. Patients underwent Hammersmith Infant Neurological Examination (HINE) or Hammersmith Functional Motor Scale Expanded (HFMSE) before treatment, and approximately every 4 months thereafter. Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) or Children's Hospital of Philadelphia - Adult Test of Neuromuscular Disorders (CHOP ATEND), Revised Upper Limb Module (RULM), and Motor Function Measure (MFM) were performed based on baseline functional status. Narrative interviews were conducted to explore post-treatment physical improvement regarding activities of daily living (ADLs) and fatigue after ADLs. Based on HFMSE results, 9 patients achieved minimum clinically important differences. Average rates of change (slopes) with corresponding 95% confidence intervals for all assessment tools were in a positive direction. CHOP-INTEND showed the most prominent improvement in children and adolescents followed by HFMSE. Improvements in CHOP-ATEND were most noticeable in adults. Improvements were accompanied by changes in ADLs as observed in the narrative interviews. It is necessary to consider various functional aspects to determine the effectiveness of Nusinersen therapy. The objective assessment of the therapeutic effect of Nusinersen in non-ambulatory SMA requires consideration of functional aspects and the related ADLs.

Nusinersen Treatment for Spinal Muscular Atrophy: Retrospective Multicenter Study of Pediatric and Adult Patients in Kuwait

Spinal muscular atrophy is a neuromuscular genetic condition associated with progressive muscle weakness and atrophy. Nusinersen is an antisense oligonucleotide therapy approved for the treatment of 5q spinal muscular atrophy in pediatric and adult patients. The objective of this clinical case series is to describe the efficacy and safety of nusinersen in treating spinal muscular atrophy in 20 pediatric and 18 adult patients across six treatment centers in Kuwait. Functional motor assessments (Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders, Hammersmith Functional Motor Scale Expanded, and Revised Upper Limb Module) were used to assess changes in motor function following nusinersen treatment. The safety assessment involved clinical monitoring of adverse events. The results demonstrate clinically meaningful or considerable improvement in motor performance for nearly all patients, lasting over 4 years in some cases. A total of 70% of patients in the pediatric cohort and 72% of patients in the adult cohort achieved a clinically meaningful improvement in motor function following nusinersen treatment. Additionally, nusinersen was well-tolerated in both cohorts. These findings add to the growing body of evidence relating to the clinical efficacy and safety of nusinersen.

Clinical Effectiveness of Newborn Screening for Spinal Muscular Atrophy: A Nonrandomized Controlled Trial

Importance

There is increasing evidence that early diagnosis and treatment are key for outcomes in infants with spinal muscular atrophy (SMA), and newborn screening programs have been implemented to detect the disease before onset of symptoms. However, data from controlled studies that reliably confirm the benefits of newborn screening are lacking.

Objective

To compare data obtained on patients with SMA diagnosed through newborn screening and those diagnosed after clinical symptom onset.

Design, Setting, and Participants

This nonrandomized controlled trial used data from the SMARTCARE registry to evaluate all children born between January 2018 and September 2021 with genetically confirmed SMA and up to 3 SMN2 copies. The registry includes data from 70 participating centers in Germany, Austria, and Switzerland. Data analysis was performed in February 2023 so that all patients had a minimal follow-up of 18 months.

Exposure

Patients born in 2 federal states in Germany underwent screening in a newborn screening pilot project. All other patients were diagnosed after clinical symptom onset. All patients received standard care within the same health care system.

Main Outcomes

The primary end point was the achievement of motor milestones.

Results

A total of 234 children (123 [52.6%] female) were identified who met inclusion criteria and were included in the analysis: 44 (18.8%) in the newborn screening cohort and 190 children (81.2%) in the clinical symptom onset cohort. The mean (SD) age at start of treatment with 1 of the approved disease-modifying drugs was 1.3 (2.2) months in the newborn screening cohort and 10.7 (9.1) months in the clinical symptom onset cohort. In the newborn screening cohort, 40 of 44 children (90.9%) gained the ability to sit independently vs 141 of 190 (74.2%) in the clinical symptom onset cohort. For independent ambulation, the ratio was 28 of 40 (63.6%) vs 28 of 190 (14.7%).

Conclusions and Relevance

This nonrandomized controlled trial demonstrated effectiveness of newborn screening for infants with SMA in the real-world setting. Functional outcomes and thus the response to treatment were significantly better in the newborn screening cohort compared to the unscreened clinical symptom onset group.

Trial Registration

German Clinical Trials Register: DRKS00012699.

Nusinersen therapy changed the natural course of spinal muscular atrophy type 1: What about spine and hip?

Purpose

Spinal muscular atrophy type 1 has a devastating natural course and presents a severe course marked by scoliosis and hip subluxation in nonambulatory patients. Nusinersen, Food and Drug Administration-approved spinal muscular atrophy therapy, extends survival and enhances motor function. However, its influence on spinal and hip deformities remains unclear.

Methods

In a retrospective study, 29 spinal muscular atrophy type 1 patients born between 2017 and 2021, confirmed by genetic testing, treated with intrathecal nusinersen, and had registered to the national electronic health database were included. Demographics, age at the first nusinersen dose, total administrations, and Children's of Philadelphia Infant Test of Neuromuscular Disorders scores were collected. Radiological assessments included parasol rib deformity, scoliosis, pelvic obliquity, and hip subluxation.

Results

Mean age was 3.7 ± 1.1 (range, 2-6), and average number of intrathecal nusinersen administration was 8.9 ± 2.9 (range, 4-19). There was a significant correlation between Children's of Philadelphia Infant Test of Neuromuscular Disorders score and the number of nusinersen administration (r = 0.539, p = 0.05). The correlation between Children's of Philadelphia Infant Test of Neuromuscular Disorders score and patient age (r = 0.361) or the time of first nusinersen dose (r = 0.39) was not significant (p = 0.076 and p = 0.054, respectively). While 93.1% had scoliosis, 69% had pelvic obliquity, and 60.7% had hip subluxation, these conditions showed no significant association with patient age, total nusinersen administrations, age at the first dose, or Children's of Philadelphia Infant Test of Neuromuscular Disorders scores.

Conclusion

Disease-modifying therapy provides significant improvements in overall survival and motor function in spinal muscular atrophy type 1. However, progressive spine deformity and hip subluxation still remain significant problems in the majority of cases which would potentially need to be addressed.

Long-Term Comparative Efficacy and Safety of Risdiplam and Nusinersen in Children with Type 1 Spinal Muscular Atrophy

INTRODUCTION

Spinal muscular atrophy (SMA) is a severe genetic neuromuscular disease characterized by a loss of motor neurons and progressive muscle weakness. Children with untreated type 1 SMA never sit independently and require increasing levels of ventilatory support as the disease progresses. Without intervention, and lacking ventilatory support, death typically occurs before the age of 2 years. There are currently no head-to-head trials comparing available treatments in SMA. Indirect treatment comparisons are therefore needed to provide information on the relative efficacy and safety of SMA treatments for healthcare decision-making.

METHODS

The long-term efficacy and safety of risdiplam versus nusinersen in children with type 1 SMA was evaluated using indirect treatment comparison methodology to adjust for differences between population baseline characteristics, to reduce any potential bias in the comparative analysis. An unanchored matching-adjusted indirect comparison was conducted using risdiplam data from 58 children in FIREFISH (NCT02913482) and published aggregate nusinersen data from 81 children obtained from the ENDEAR (NCT02193074) and SHINE (NCT02594124) clinical trials with at least 36 months of follow-up.

RESULTS

Children with type 1 SMA treated with risdiplam had a 78% reduction in the rate of death, an 81% reduction in the rate of death or permanent ventilation, and a 57% reduction in the rate of serious adverse events compared with children treated with nusinersen. Children treated with risdiplam also had a 45% higher rate of achieving a Hammersmith Infant Neurological Examination, Module 2 motor milestone response and a 186% higher rate of achieving a ≥ 4-point improvement in Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders compared with children treated with nusinersen.

CONCLUSION

Long-term data supported risdiplam as a superior alternative to nusinersen in children with type 1 SMA. Video abstract available for this article. Video abstract (MP4 184542 KB).

E-Health & Innovation to Overcome Barriers in Neuromuscular Diseases. Report from the 3rd eNMD Congress: Pisa, Italy, 29-30 October 2021: Remote Monitoring: New Solutions for New Avenues in Neuromuscular Disorders

Neuromuscular diseases (NMDs), in their phenotypic heterogeneity, share quite invariably common issues that involve several clinical and socio-economical aspects, needing a deep critical analysis to develop better management strategies. From diagnosis to treatment and follow-up, the development of technological solutions can improve the detection of several critical aspects related to the diseases, addressing both the met and unmet needs of clinicians and patients. Among several aspects of the digital transformation of health and care, this congress expands what has been learned from previous congresses editions on applicability and usefulness of technological solutions in NMDs. In particular the focus on new solutions for remote monitoring provide valuable insights to increase disease-specific knowledge and trigger prompt decision-making. In doing that, several perspectives from different areas of expertise were shared and discussed, pointing out strengths and weaknesses on the current state of the art on topic, suggesting new research lines to advance technology in this specific clinical field.

Longitudinal changes of swallowing safety and efficiency in infants with spinal muscular atrophy who received disease modifying therapies

BACKGROUND

Dysphagia is a common feature of the natural history of patients with spinal muscular atrophy (SMA). Literature regarding swallowing safety and efficiency is scarce in patients with SMA, particularly in the era of newborn screening programs and disease-modifying therapies.

OBJECTIVE

To describe the longitudinal changes of swallowing safety and efficiency in children with SMA who received one or more disease modifying therapies METHODS: Case series of patients with SMA followed at the University of Florida from 1 May 2019 to 31 December 2022 who had two or more videofluoroscopy swallowing studies (VFSS), with the first being within 30 days of their first treatment. Data extracted from the electronic health record included: neuromotor outcomes, VFSS penetration aspiration scores (PAS), presence of abrnormal oral or pharyngeal residue, clinical history, and timing of disease-modifying therapies administration.

RESULTS

Seven subjects were included (five male); three were diagnosed via newborn screen. Median age at diagnosis was 10 days (range: 4-250). Median age at initial VFSS was 29 days (range: 9-246), and age at the last VFSS was 26.1 months (range: 18.2-36.2). All subjects received onasemnogene-abeparvovec (OA); four received additional therapies. PAS at diagnosis was abnormal in four subjects. Six subjects required feeding modifications after VFSS results. Of these, three had silent aspiration (PAS 8) and three of them improved after treatment.

CONCLUSIONS

Swallowing safety and efficiency can be impaired in patients with SMA despite early treatment. Larger, prospective studies are needed to define optimal timiing of longitudinal instrumental evaluations.

Development of an Infantile GM2 Clinical Rating Scale: Remote Assessment of Clinically Meaningful Health-Related Function

GM2 gangliosidoses (GM2) are a group of rare lysosomal storage disorders in which accumulation of GM2 gangliosides results in progressive central nervous system damage. The infantile GM2 phenotype is characterized by delays in milestones by 6 months of age, followed by rapid loss of motor, cognitive, and visual function. Advancements in early diagnosis and pharmacotherapies provide promise for improved outcomes. However, the lack of feasible and clinically meaningful clinical outcome assessments for GM2 poses a challenge to characterizing GM2 natural history and selecting clinical trial endpoints. The purpose of this study was to develop a remotely administered infantile GM2 rating scale to measure health-related function in children with infantile GM2. A 2-phase mixed methods design was employed. In phase 1 of the study, 8 families of children with Infantile GM2 completed a natural history survey and a 1:1 semistructured interview to provide caregiver perspectives on the impacts of GM2 on health-related function. In phase 2 of the study, 8 expert clinicians provided feedback via surveys and participated in videoconference-hosted focus groups to refine scale administration and scoring procedures. These methods guided the development of 16 scale items to assess function in 5 health-related function domains: vision, hand and arm use, communication, gross motor, and feeding. This study used caregiver perspectives and expert clinician feedback to develop a remotely administered clinical outcome assessment of clinically meaningful health-related function in children with infantile GM2. Future studies will further evaluate the feasibility, reliability, and validity of the Infantile GM2 Clinical Rating Scale.

Anaplerotic Therapy Using Triheptanoin in Two Brothers Suffering from Aconitase 2 Deficiency

Citric acid cycle deficiencies are extremely rare due to their central role in energy metabolism. The ACO2 gene encodes the mitochondrial isoform of aconitase (aconitase 2), the second enzyme of the citric acid cycle. Approximately 100 patients with aconitase 2 deficiency have been reported with a variety of symptoms, including intellectual disability, hypotonia, optic nerve atrophy, cortical atrophy, cerebellar atrophy, and seizures. In this study, a homozygous deletion in the ACO2 gene in two brothers with reduced aconitase 2 activity in fibroblasts has been described with symptoms including truncal hypotonia, optic atrophy, hyperopia, astigmatism, and cerebellar atrophy. In an in vivo trial, triheptanoin was used to bypass the defective aconitase 2 and fill up the citric acid cycle. Motor abilities in both patients improved.

Total tau in cerebrospinal fluid detects treatment responders among spinal muscular atrophy types 1-3 patients treated with nusinersen

AIMS

Considering the substantial variability in treatment response across patients with spinal muscular atrophy (SMA), reliable markers for monitoring response to therapy and predicting treatment responders need to be identified. The study aimed to determine if measured concentrations of disease biomarkers (total tau protein, neurofilament light chain, and S100B protein) correlate with the duration of nusinersen treatment and with scores obtained using functional scales for the assessment of motor abilities.

METHODS

A total of 30 subjects with SMA treated with nusinersen between 2017 and 2021 at the Department of Pediatrics, University Hospital Centre Zagreb, Croatia, were included in this study. Cerebrospinal fluid (CSF) samples were collected by lumbar puncture prior to intrathecal application of nusinersen. Protein concentrations in CSF samples were determined by enzyme-linked immunosorbent assay in 26 subjects. The motor functions were assessed using functional motor scales.

RESULTS

The main finding was significantly decreased total tau correlating with the number of nusinersen doses and motor improvement in the first 18-24 months of treatment (in all SMA patients and SMA type 1 patients). Neurofilament light chain and S100B were not significantly changed after administration of nusinersen.

CONCLUSIONS

The measurement of total tau concentration in CSF is a reliable index for monitoring the biomarker and clinical response to nusinersen therapy in patients with SMA.

Motor and neurocognitive profiles of children with symptomatic spinal muscular atrophy type 1 with two copies of SMN2 before and after treatment: a longitudinal observational study

Introduction

Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by mutations in the survival motor neuron 1 (SMN1) gene. In clinical studies, gene replacement therapy with onasemnogene abeparvovec (formerly AVXS-101, Zolgensma®, Novartis) was efficacious in improving motor functioning in children with SMA. However, its effects on cognitive and language skills are largely unknown.

Methods

This longitudinal observational study evaluated changes in motor and neurocognitive functioning over a 1-year period after administration of onasemnogene abeparvovec in 12 symptomatic SMA type 1 patients with two copies of SMN2 aged 1.7-52.6 months at administration. Motor functioning was measured using the Children's Hospital of Philadelphia Infant Test for Neuromuscular Disorders (CHOP-INTEND) while neurocognitive assessment was measured using Griffiths III. Motor milestones and language ability were also assessed at each timepoint.

Results and discussion

Statistically significant increases in median CHOP-INTEND scores from baseline were observed at 1, 3, 6, and 12 months after onasemnogene abeparvovec administration (all p ≤ 0.005). Most (91.7%) patients were able to roll over or sit independently for >1 min at 12 months. Significant increases in the Griffiths III Foundations of Learning, Language and Communication, Eye and Hand Coordination, and Personal-Social-Emotional subscale scores were observed at 12-months, but not in the Gross Motor subscale. Speech and language abilities progressed in most patients. Overall, most patients showed some improvement in cognitive and communication performance after treatment with onasemnogene abeparvovec in addition to significant improvement in motor functioning and motor milestones. Evaluation of neurocognitive function should be considered when assessing the global functioning of patients with SMA.

Criterion validity of the spatial exploration test of upper limb mobility to evaluate the active horizontal workspace of children with spinal muscular atrophy

PURPOSE

To determine the criterion validity of the SET-ULM (Spatial Exploration Test of Upper Limb Mobility), a functional workspace test.

MATERIALS AND METHODS

A prospective study from July 2017 to November 2018 in 30 children with SMA type 1 or 2. All children underwent assessment with the SET-ULM and the Motor Function Measure (MFM).

RESULTS

We included 30 children. Median (Q1; Q3) MFM D1 (standing ability, ambulation and transfers), D2 (axial and proximal motor function), D3 (distal motor function) scores, Total MFM and Total SET-ULM active score were respectively 2.6% (2.6-3.8); 45.8% (19.9-65.3); 57.7% (36.9-80.9); 35.4% (16.7-43.2) and 70.2% (49.7-97.9). Total SET-ULM active score was strongly correlated with the MFM D2 dimension score (rho 0.82; p < 001), with the D3 dimension (rho 0.86; p < 0.001) and with the Total MFM score (rho 0.89; p < 0.005). Total SET-ULM active score differed between SMA types (p < 0.01).

CONCLUSION

The SET-ULM has good criterion validity for the evaluation of available horizontal active upper limb workspace in children with SMA1 and SMA2. Future studies should evaluate reliability and sensitivity to change during a longitudinal follow-up study, as well as in a longitudinal trial of therapeutic effectiveness.

CLINICAL TRIALS

NCT03223051IMPLICATIONS FOR REHABILITATIONThe Spatial Exploration Test for Upper Limb Mobility is a useful adjunct to the Motor Function Measure.It provides a precise evaluation of horizontal reaching ability.The Spatial Exploration Test for Upper Limb Mobility will be of great clinical utility for the evaluation of the effects of treatments for spinal muscular atrophy.