Clinical perspectives: Treating spinal muscular atrophy.

Spinal muscular atrophy is a rare and progressive neuromuscular disease that, without treatment, leads to progressive weakness and often death. A plethora of studies have led to the approval of three high-cost and effective treatments since 2016. These treatments, nusinersen, onasemnogene abeparvovec, and risdiplam, have not been directly compared and have varying challenges in administration. In this review, we discuss the evidence supporting the use of these medications, the process of treatment selection, monitoring after treatment, the limited data comparing treatments, as well as future directions for investigation and therapy.

A case series evaluating patient perceptions after switching from nusinersen to risdiplam for spinal muscular atrophy.

INTRODUCTION/AIMS: In 2016, nusinersen became the first disease-modifying medication approved by the U.S. Food and Drug Administration (FDA) for spinal muscular atrophy (SMA). With the later availability of risdiplam in 2020, individuals now have the option of switching from nusinersen to risdiplam. Limited published data exist to inform this decision. This study aims to evaluate the perceptions and experiences of adult participants and parents of minor participants who previously received nusinersen and switched to risdiplam for the treatment of SMA. METHODS: Institutional Review Board (IRB) approval was obtained from the Wake Forest IRB prior to the initiation of this study. A cross-sectional, observational study, with qualitative and quantitative data gathered via questionnaire and medical record review, was performed. Inclusion criteria included (1) prior diagnosis of SMA, (2) previous treatment with nusinersen, and (3) change to treatment with risdiplam. No participants were excluded based on age. RESULTS: Fourteen participants-eight adults and six children-were enrolled in the study. Respondents noted improvements in physical function with each medication. Overall, respondents reported worse satisfaction with the method of delivery of the intrathecally delivered nusinersen compared to the orally-delivered risdiplam, but no respondent reported negative overall satisfaction with either medication. A majority (78.6%) of respondents reported that switching from nusinersen to risdiplam was the correct decision. DISCUSSION: These results suggest that most patients are satisfied when switching from nusinersen to risdiplam, with the method of delivery being a primary factor.

Transverse interlaminar ultrasound-guided C1-C2 puncture for the intrathecal administration of nusinersen in patients with spinal muscular atrophy.

INTRODUCTION/AIMS: Severe spinal deformities and previous spinal orthopedic instrumentation may result in substantial technical challenges for nusinersen delivery through lumbar puncture in patients with spinal muscular atrophy (SMA). The aim of this paper was to review our experience with ultrasound-guided cervical puncture as an alternative approach for the intrathecal administration of nusinersen. METHODS: This was a retrospective medical record review of transverse interlaminar ultrasound-guided C1-C2 puncture for nusinersen delivery in SMA patients. The details of puncture, complications, and success rate of the procedure were summarized. RESULTS: There were four patients who received a total of 13 cervical punctures for nusinersen delivery. All procedures were technically successful with no major complications. Full doses of nusinersen were delivered intrathecally. DISCUSSION: Transverse interlaminar ultrasound-guided C1-C2 puncture is an alternative approach for administering nusinersen if lumbar puncture fails. The success of the technique requires a thorough preprocedural evaluation of cervical spine imaging, sound knowledge of the cervical sonoanatomy and careful manipulation of the needle.

Neurofilament light chain and profilin-1 dynamics in 30 spinal muscular atrophy type 3 patients treated with nusinersen.

BACKGROUND AND PURPOSE: The aim was to investigate whether neurofilament light chain (NfL) and profilin-1 (PFN-1) might qualify as surrogate disease and treatment-response biomarkers by correlating their concentrations dynamic with clinical status in a cohort of 30 adult spinal muscular atrophy type 3 patients during nusinersen therapy up to 34 months. METHODS: Neurofilament light chain was measured in cerebrospinal fluid at each drug administration with a commercial enzyme-linked immunosorbent assay (ELISA); PFN-1 concentrations were tested in serum sampled at the same time points with commercial ELISA assays. Functional motor scores were evaluated at baseline, at the end of the loading phase and at each maintenance dose and correlated to biomarker levels. The concurrent effect of age and clinical phenotype was studied. RESULTS: Neurofilament light chain levels were included in the reference ranges at baseline; a significant increase was measured during loading phase until 1 month. PFN-1 was higher at baseline than in controls and then decreased during therapy until reaching control levels. Age had an effect on NfL but not on PFN-1. NfL was partially correlated to functional scores at baseline and at last time point, whilst no correlation was found for PFN-1. CONCLUSION: Cerebrospinal fluid NfL levels did not qualify as an optimal surrogate treatment biomarker in adult spinal muscular atrophy patients with a long disease duration, whilst PFN-1 might to a greater extent represent lower motor neuron pathological processes. The observed biomarker level variation during the first 2 months of nusinersen treatment might suggest a limited effect on axonal remodeling or rearrangement.

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.

Effect of nusinersen on motor, respiratory and bulbar function in early-onset spinal muscular atrophy.

5q-associated spinal muscular atrophy is a rare neuromuscular disorder with the leading symptom of a proximal muscle weakness. Three different drugs have been approved by the European Medicines Agency and Food and Drug Administration for the treatment of spinal muscular atrophy patients, however, long-term experience is still scarce. In contrast to clinical trial data with restricted patient populations and short observation periods, we report here real-world evidence on a broad spectrum of patients with early-onset spinal muscular atrophy treated with nusinersen focusing on effects regarding motor milestones, and respiratory and bulbar insufficiency during the first years of treatment. Within the SMArtCARE registry, all patients under treatment with nusinersen who never had the ability to sit independently before the start of treatment were identified for data analysis. The primary outcome of this analysis was the change in motor function evaluated with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders and motor milestones considering World Health Organization criteria. Further, we evaluated data on the need for ventilator support and tube feeding, and mortality. In total, 143 patients with early-onset spinal muscular atrophy were included in the data analysis with a follow-up period of up to 38 months. We observed major improvements in motor function evaluated with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders. Improvements were greater in children >2 years of age at start of treatment than in older children. 24.5% of children gained the ability to sit independently. Major improvements were observed during the first 14 months of treatment. The need for intermittent ventilator support and tube feeding increased despite treatment with nusinersen. Our findings confirm the increasing real-world evidence that treatment with nusinersen has a dramatic influence on disease progression and survival in patients with early-onset spinal muscular atrophy. Major improvements in motor function are seen in children younger than 2 years at the start of treatment. Bulbar and respiratory function needs to be closely monitored, as these functions do not improve equivalent to motor function.

Health-related quality of life of adults with spinal muscular atrophy: insights from a nationwide patient registry in Germany.

PURPOSE: Spinal muscular atrophy (SMA) is a rare, autosomal-recessive disease characterized by progressive muscular atrophy and weakness resulting in substantial disability and short life expectancy. The objective of this cross-sectional study was to assess health-related quality of life (HRQoL) of adults with SMA in Germany in the era of disease-modifying therapy. METHODS: Adults with SMA were recruited via the German national TREAT-NMD SMA patient registry. HRQoL was measured using the EQ-5D-5L, the Health Utilities Index Mark III (HUI), and the Short Form (36) Health Survey (SF-36). Estimates were stratified by current best motor function of the lower limb and trunk (i.e., non-sitter, sitter, and walker) and SMA type (i.e., type I, II, and III). RESULTS: A total of 82 adults with SMA (mean age: 42 years, 51% female) self-completed the study questionnaire. The mean EQ-5D-5L utility was estimated at 0.5135 (range across subgroups: 0.31-0.99), mean EQ-VAS at 69.71 (64.67-90.00), mean HUI-derived utility at 0.3171 ( - 0.02-0.96), mean SF-6D utility at 0.6308 (0.58-0.65), and mean SF-36 Physical Component Summary and Mental Health Component Summary scores at 33.78 (9.92-53.10) and 53.49 (21.02-72.25), respectively. CONCLUSIONS: We show that adults with SMA experience considerable impairment across a wide range of health dimensions, including mobility, dexterity, pain, and emotional well-being. However, our results exhibit non-trivial variability across clinical subgroups and HRQoL measures. These data contribute to our understanding of the subjective impact of living with a severely debilitating neuromuscular disease, such as SMA.

A Real-World Study of Nusinersen Effects in Adults with Spinal Muscular Atrophy Type 2 and 3.

BACKGROUND: Spinal muscular atrophy (SMA) is a progressive genetic disorder characterized by muscle weakness ultimately leading to pulmonary impairments that can be fatal. The recent approval of nusinersen, a disease-modifying therapy, substantially changed the prognosis for patients, particularly in children. However, real-world evidence about its long-term effectiveness in adults remains limited. This study aimed to document longitudinal data on motor function, pulmonary function and patient-reported outcome measures of Canadian adults with SMA type 2 and 3 treated with nusinersen. METHODS: Outcomes from 17 patients were collected at the Institut de réadaptation en déficience physique de Québec during routine clinical visits over 36 months post nusinersen treatment, using the Hammersmith Functional Motor Scale Expanded for SMA (HFMSE), Revised Upper Limb Module (RULM), 6-Minute Walk Test (6MWT), Children's Hospital of Philadelphia Adult Test of Neuromuscular Disorders (CHOP-ATEND), SMA functional rating scale (SMAFRS), pulmonary function testing and subjective changes reported by patients. RESULTS: After 36 months, 9 patients showed motor function improvement. Changes beyond the minimal clinically important difference were seen for four patients on the HFMSE, four patients on the RULM and five patients on the 6MWT. Pulmonary function remained stable for most subjects. Subjective positive changes were reported in 88% of patients and five patients showed improvement in the SMAFRS. CONCLUSION: This real-world study demonstrates the positive effects of nusinersen in adults with SMA types 2 and 3. Although stabilizing the patient's condition is considered therapeutic success, this study shows an improvement in motor function and subjective gains in several patients.

Nusinersen in adults with type 3 spinal muscular atrophy: long-term outcomes on motor and respiratory function.

INTRODUCTION: Nusinersen was approved for 5q spinal muscular atrophy (SMA), irrespective of age, SMA type or functional status. Nonetheless, long-term data on adults with milder phenotypes are scarce. We aimed to characterize evolution on motor and respiratory function in our cohort of adults with type 3 SMA. METHODS: We conducted a longitudinal retrospective single-center study, including adults (≥18 years) with type 3 SMA under nusinersen for > 22 months. We reported on motor scores and spirometry parameters. RESULTS: Ten patients were included, with a median follow-up of 34 months (range = 22-46). Four patients (40%) were walkers. None used non-invasive ventilation. In Revised Upper Limb Module (RULM) and Expanded Hammersmith Functional Motor Scale (HFMSE), difference of medians increased at 6, 22 and 46 months comparing to baseline (-0.5 vs. + 1.5 vs. + 2.5 in RULM; + 4.0 vs. + 7.5 vs. + 6.0 in HFMSE). Two (50%) walkers presented a clinically meaningful improvement in 6-min walk distance. We did not report any clinically meaningful decrement in motor scores. Spirometry parameters showed an increasing difference of medians in maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) (-3 vs. + 13.4 vs. + 28.7 percentage points of predicted value for MIP; + 11.8 vs. + 13.1 vs. 13.3 percentage points of predicted value for MEP). DISCUSSION: Our cohort supports a sustained benefit of nusinersen in adults with type 3 SMA, in motor and respiratory function. Multicentric studies are still warranted.

Safety analysis of laboratory parameters in paediatric patients with spinal muscular atrophy treated with nusinersen.

BACKGROUND: Spinal muscular atrophy (SMA) is a progressive neurodegenerative disorder that can be treated with intrathecal nusinersen, an antisense oligonucleotide. In addition to efficacy, safety is a determining factor in the success of any therapy. Here, we aim to assess the safety of nusinersen therapy in paediatric patients with SMA. METHODS: Laboratory data of paediatric patients with SMA who received nusinersen between October 2019 and May 2022 were retrospectively analysed. RESULTS: During the observation period, 46 infants and children aged 2.9 months to 13.6 years received a total of 213 nusinersen doses without safety concerns. Inflammatory markers were stable throughout the study. International normalized ratio was increased by 0.09 per injection. Urea levels were increased by 0.108 mmol/L, and cystatin C decreased by 0.029 mg/L per injection. There were no significant changes in platelet count, activated partial thrombin time, creatinine levels or liver enzyme levels during treatment. The cerebrospinal fluid (CSF) leukocyte count remained stable, and total protein increased by 24.038 mg/L per injection. CONCLUSION: Our data showed that nusinersen therapy is generally safe in children with SMA. Laboratory monitoring did not identify any persistent or significantly abnormal findings. CSF protein should be monitored to gain more insights.

Neurodegeneration Biomarkers in Adult Spinal Muscular Atrophy (SMA) Patients Treated with Nusinersen.

The objective of this study is to evaluate biomarkers for neurodegenerative disorders in adult SMA patients and their potential for monitoring the response to nusinersen. Biomarkers for neurodegenerative disorders were assessed in plasma and CSF samples obtained from a total of 30 healthy older adult controls and 31 patients with adult SMA type 2 and 3. The samples were collected before and during nusinersen treatment at various time points, approximately at 2, 6, 10, and 22 months. Using ELISA technology, the levels of total tau, pNF-H, NF-L, sAPPß, Aß40, Aß42, and YKL-40 were evaluated in CSF samples. Additionally, plasma samples were used to measure NF-L and total tau levels using SIMOA technology. SMA patients showed improvements in clinical outcomes after nusinersen treatment, which were statistically significant only in walkers, in RULM (p = 0.04) and HFMSE (p = 0.05) at 24 months. A reduction in sAPPß levels was found after nusinersen treatment, but these levels did not correlate with clinical outcomes. Other neurodegeneration biomarkers (NF-L, pNF-H, total tau, YKL-40, Aß40, and Aß42) were not found consistently changed with nusinersen treatment. The slow progression rate and mild treatment response of adult SMA types 2 and 3 may not lead to detectable changes in common markers of axonal degradation, inflammation, or neurodegeneration, since it does not involve large pools of damaged neurons as observed in pediatric forms. However, changes in biomarkers associated with the APP processing pathway might be linked to treatment administration. Further studies are warranted to better understand these findings.

Antisense Oligonucleotides (ASOs) in Motor Neuron Diseases: A Road to Cure in Light and Shade.

Antisense oligonucleotides (ASOs) are short oligodeoxynucleotides designed to bind to specific regions of target mRNA. ASOs can modulate pre-mRNA splicing, increase levels of functional proteins, and decrease levels of toxic proteins. ASOs are being developed for the treatment of motor neuron diseases (MNDs), including spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS) and spinal and bulbar muscular atrophy (SBMA). The biggest success has been the ASO known as nusinersen, the first effective therapy for SMA, able to improve symptoms and slow disease progression. Another success is tofersen, an ASO designed to treat ALS patients with SOD1 gene mutations. Both ASOs have been approved by the FDA and EMA. On the other hand, ASO treatment in ALS patients with the C9orf72 gene mutation did not show any improvement in disease progression. The aim of this review is to provide an up-to-date overview of ASO research in MNDs, from preclinical studies to clinical trials and, where available, regulatory approval. We highlight the successes and failures, underline the strengths and limitations of the current ASO research, and suggest possible approaches that could lead to more effective treatments.

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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.

Impaired diaphragmatic motility in treatment-naive adult patients with spinal muscular atrophy improved during nusinersen treatment.

INTRODUCTION/AIMS: The leading clinical feature of 5q-associated spinal muscular atrophy (SMA) is symmetric, proximal muscle weakness. Muscles involved in ventilation exhibit a specific pattern of denervation: intercostal muscles are severely atrophic, whereas the diaphragm muscle is less affected. The aim of this study was to investigate the involvement of diaphragmatic function by ultrasound imaging in adult patients with SMA and to quantify dynamics of diaphragmatic function during nusinersen treatment. METHODS: Diaphragmatic thickness, thickening, and excursion during quiet breathing were assessed in 24 adult patients with SMA type 2 and 3 by diaphragm ultrasound imaging before and during nusinersen treatment and were correlated with spirometric parameters. RESULTS: Diaphragm thickness was not reduced, but increased in a remarkable proportion of patients, whereas diaphragm thickening and excursion were reduced in about 20% to 30% of nusinersen-naive, adult patients with SMA types 2 and 3. During 26 months of nusinersen treatment, diaphragm thickening fraction and excursion improved. DISCUSSION: Diaphragm ultrasound imaging can provide disease- and treatment-relevant information that is not identified during routine clinical assessments and may therefore be a valuable complementary outcome measure.

Continued benefit of nusinersen initiated in the presymptomatic stage of spinal muscular atrophy: 5-year update of the NURTURE study.

INTRODUCTION/AIMS: NURTURE (NCT02386553) is an open-label study of nusinersen in children (two SMN2 copies, n = 15; three SMN2 copies, n = 10) who initiated treatment in the presymptomatic stage of spinal muscular atrophy (SMA). A prior analysis after ~3 y showed benefits on survival, respiratory outcomes, motor milestone achievement, and a favorable safety profile. An additional 2 y of follow-up (data cut: February 15, 2021) are reported. METHODS: The primary endpoint is time to death or respiratory intervention (≥6 h/day continuously for ≥7 days or tracheostomy). Secondary outcomes include overall survival, motor function, and safety. RESULTS: Median age of children was 4.9 (3.8-5.5) y at last visit. No children have discontinued the study or treatment. All were alive. No additional children utilized respiratory intervention (defined per primary endpoint) since the prior data cut. Children with three SMN2 copies achieved all World Health Organization (WHO) motor milestones, with all but one milestone in one child within normal developmental timeframes. All 15 children with two SMN2 copies achieved sitting without support, 14/15 walking with assistance, and 13/15 walking alone. Mean Hammersmith Functional Motor Scale Expanded total scores showed continued improvement. Subgroups with two SMN2 copies, minimum baseline compound muscle action potential amplitude ≥2 mV, and no baseline areflexia had better motor and nonmotor outcomes versus all children with two SMN2 copies. DISCUSSION: These results demonstrate the value of early treatment, durability of treatment effect, and favorable safety profile after ~5 y of nusinersen treatment. Inclusion/exclusion criteria and baseline characteristics should be considered when interpreting presymptomatic SMA trial data.

Feasibility of intrathecal therapeutic injections in spinal muscular atrophy patients via a percutaneous transsacral hiatus route: An initial neuroimaging morphometric study.

INTRODUCTION/AIMS: Standard fluoroscopic lumbar puncture (LP) can be impossible in patients with severe spinal deformities from spinal muscular atrophy (SMA) who require intrathecal nusinersen therapy. There usually exists a straight trajectory in the lower sacral canal (SC) that could allow image-guided percutaneous transsacral hiatus puncture of the lumbosacral dural sac. In this study we determine whether sacra are comparatively straighter in SMA patients (SMAps) vs healthy controls (HCs), which may facilitate unhindered transsacral hiatus spinal needle insertion for intrathecal nusinersen therapy. METHODS: We retrospectively analyzed lumbosacral spine computed tomograms (CTs) or CT-myelogram images of 38 SMAps and age- and sex-matched HCs. We digitally measured ventrodorsal sacral curvatures, SC surface areas, dural sac termination levels, and distances from sacral hiatus to the most caudad aspects of dural sacs ("needle distance"). RESULTS: Mean ages of HCs and SMAps were 32.7 and 31.7 years, respectively, with dural sacs terminating at similar levels. Mean values for morphometrics were: (a) midsagittal SC surface area for HCs = 701.2 mm2 , and for SMAps = 601.5 mm2 (not statistically significant [ns]); (b) using a "line method," sacral curvature for HCs = 61.9°, and SMAp = 35.7° (P = .0009), and was similar when using an "angle summation method"; (c) width of sacral hiatus for HCs = 14.9 mm, and SMAps = 15.0 mm (ns); and (d) "needle distance" for HCs = 54.7 mm, and SMAps = 49.9 mm (ns). DISCUSSION: SMAps have significantly straighter sacra compared with HCs, which theoretically renders them more amenable to percutaneous transsacral hiatus puncture of the dural sac.

Impact of nusinersen on the health-related quality of life and caregiver burden of patients with spinal muscular atrophy with symptom onset after age 6 months.

INTRODUCTION/AIMS: Novel disease-modifying approaches for spinal muscular atrophy (SMA) have highlighted the patient's perspective on functional changes over time. In this study, we evaluated the impact of nusinersen on the health-related quality of life (HRQoL) of patients with later-onset SMA and the caregiver burden. METHODS: We assessed the changes in HRQoL using the Pediatric Quality of Life Inventory 4.0 Generic Core Scale (PedsQL GCS) and the Pediatric Quality of Life Inventory 3.0 Neuromuscular Module (PedsQL NMM) during 26 months of treatment. Caregiver burden was assessed using the Assessment of Caregiver Experience with Neuromuscular Disease. We also assessed motor function using the Hammersmith Functional Motor Scale-Expanded (HFMSE) and the Revised Upper Limb Module score. RESULTS: Twenty-four patients and their caregivers were included. The median age of patients at treatment onset was 148.8 (6.8 to 269.4) months. A significant improvement was observed in psychosocial health in proxy-reported PedsQL (P = .023). However, the physical health scores of the PedsQL GCS and About my neuromuscular disorder subscores of the PedsQL NMM did not change, although there was a significant increase in HFMSE scores. Regarding the caregiver burden, the financial burden was reduced, whereas time burden increased. A higher HFMSE score was associated with better self-reported PedsQL GCS total scores (P < .001). DISCUSSION: Our results provide insights into the multifaceted implications of disease-modifying therapies for SMA through patient-reported outcome measures (PROMs). PROMs should be taken into consideration to assess the clinical significance of the functional changes identified by clinician-reported scales.

Type I spinal muscular atrophy patients treated with nusinersen: 4-year follow-up of motor, respiratory and bulbar function.

BACKGROUND: We report the 4-year follow-up in type I patients treated with nusinersen and the changes in motor, respiratory and bulbar function in relation to subtype, age and SMN2 copy number. METHODS: The study included SMA 1 patients with at least one assessment after 12, 24 and 48 months from the first dose of nusinersen. The assessments used were Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) and the Hammersmith Infant Neurological Examination (HINE-II). RESULTS: Forty-eight patients, with ages ranging from 7 days to 12 years (mean 3.3 years, SD 3.6 years) were included in the study. The CHOP INTEND and HINE-II scores significantly increased between baseline and 48 months (p < 0.001). When age at starting treatment subgroups (<210 days, <2 years, 2-4 years, 5-11 years, ≥12 years) were considered, the CHOP INTEND increased significantly in patients younger than 4 years at treatment, while the HINE-2 increased significantly in patients younger than 2 years at treatment. In a mixed-model analysis, age, nutritional and respiratory status were predictive of changes on both scales while SMN2 copy number and decimal classification were not. CONCLUSIONS: Our results confirm the safety profile previously reported and support the durability of the efficacy of nusinersen at 4 years with an overall stability or mild improvement and no evidence of deterioration over a long period of time.

Spinal muscular atrophy with hypoplasia of the corpus callosum: a case report.

BACKGROUND: Spinal Muscular Atrophy (SMA) is a severe neuromuscular disorder due to a defect in the survival motor neuron 1 (SMN1) gene. Hypoplasia of the corpus callosum is underdevelopment or thinness of the corpus callosum. SMA and callosal hypoplasia are relatively rare, and there is limited information sharing the diagnosis and treatment for SMA patients with callosal hypoplasia. CASE DESCRIPTION: A boy with callosal hypoplasia, small penis, and small testes had been perceived with motor regression at 5 months. He was referred to the rehabilitation department and neurology department at 7 months. Physical examination showed absent deep tendon reflexes, proximal weakness and significant hypotonia. He was recommended to perform trio whole-exome sequencing (WES) and array comparative genomic hybridization (aCGH) for his complicated conditions. The subsequent nerve conduction study revealed some characteristics of motor neuron diseases. We identified a homozygous deletion in exon 7 of the SMN1 gene by multiplex ligation-dependent probe amplification and failed to find further pathogenic variations responsible for multiple malformations by trio WES and aCGH. He was diagnosed as SMA. Despite some concerns, he received the therapy of nusinersen for nearly 2 years. He gained the milestone of sitting without support, which he had never accomplished, after the seventh injection, and he continued to improve. During follow-up, there were no adverse events reported and no signs of hydrocephalus. CONCLUSIONS: Some extra features which could not belong to neuromuscular manifestation made the diagnosis and treatment of SMA more complicated.

Assessment of motor function and nutritional status in children with spinal muscular atrophy treated with nusinersen after loading period in Western China: a retrospective study.

BACKGROUND: Spinal muscular atrophy (SMA) is a progressive degenerative neuromuscular disease. Nusinersen, with its quick onset of action, can benefit patients early in the treatment course. However, there are currently no clinical studies regarding the improvement in motor function and nutritional status of patients after loading period treatment with nusinersen. Here, we aimed to determine the efficacy of nusinersen in improving motor function and nutritional status in children with SMA treated with nusinersen after loading period in Western China. METHODS: In this retrospective study, data for all pediatric patients (aged < 18 years), with genetically confirmed diagnosis of SMA who were treated with nusinersen, were collected before initiation of treatment and after 2 months of treatment. We assessed motor function using standardized scales and nutritional status of patients with SMA as well as side effects of nusinersen. RESULTS: Forty-six pediatric patients aged < 18 years were enrolled in this study. After 2 months of treatment, the motor function of patients with SMA type 1, 2, and 3 improved. The difference in Revised Upper Limb Module scores from M0 to M2 was significant in patients with SMA type 2 and 3 (P = 0.004, P = 0.042, respectively). The difference in Hammersmith Functional Motor Scale Expanded scores from M0 to M2 in patients with SMA type 2 was also significant (P = 0.000). No significant differences were found for Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorder (CHOP-INTEND), Hammersmith Infant Neurologic Examination-Part 2 (HINE-2), and 6-Minute Walking Test (6MWT) scores between M0 and M2, but the scores of CHOP-INTEND, HINE-2, and 6MWT were all increased after loading period treatment. The overall improvement in nutritional status was not statistically significant. No serious adverse effects were observed. CONCLUSIONS: Our study provides evidence for the efficacy and safety of nusinersen and the nutritional status of pediatric patients with SMA after the loading period treatment. Motor function of all patients improved after 2 months of loading period nusinersen treatment. Patients with a shorter disease duration showed better response to treatment. Careful surveillance of nutritional status is needed in patients with SMA.