The IAAM LTBP4 Haplotype is Protective Against Dystrophin-Deficient Cardiomyopathy.

Background: Dilated cardiomyopathy (DCM) is a major complication of, and leading cause of mortality in Duchenne muscular dystrophy (DMD). Its severity, age at onset, and rate of progression display wide variability, whose molecular bases have been scarcely elucidated. Potential DCM-modifying factors include glucocorticoid (GC) and cardiological treatments, DMD mutation type and location, and variants in other genes. Methods and Results: We retrospectively collected 3138 echocardiographic measurements of left ventricular ejection fraction (EF), shortening fraction (SF), and end-diastolic volume (EDV) from 819 DMD participants, 541 from an Italian multicentric cohort and 278 from the Cooperative International Neuromuscular Group Duchenne Natural History Study (CINRG-DNHS). Using generalized estimating equation (GEE) models, we estimated the yearly rate of decrease of EF (-0.80%) and SF (-0.41%), while EDV increase was not significantly associated with age. Utilizing a multivariate generalized estimating equation (GEE) model we observed that mutations preserving the expression of the C-terminal Dp71 isoform of dystrophin were correlated with decreased EDV (-11.01 mL/m2, p = 0.03) while for dp116 were correlated with decreased EF (-4.14%, p = <0.001). The rs10880 genotype in the LTBP4 gene, previously shown to prolong ambulation, was also associated with increased EF and decreased EDV (+3.29%, p = 0.002, and -10.62 mL/m2, p = 0.008) with a recessive model. Conclusions: We quantitatively describe the progression of systolic dysfunction progression in DMD, confirm the effect of distal dystrophin isoform expression on the dystrophin-deficient heart, and identify a strong effect of LTBP4 genotype of DCM in DMD.

A Longitudinal Follow-Up Study of Intellectual Function in Duchenne Muscular Dystrophy over Age: Is It Really Stable?

The aim of the study was to retrospectively evaluate the consistency of longitudinal findings on intellectual functioning in DMD boys and their relationship to behavioral and neuropsychiatric difficulties. The cohort included 70 patients of age 3 to 17 years with at least two assessments using the Wechsler scales. CBCL and clinical observation of behavior were also performed. Changes in total intelligence quotient were interpreted as stable or not stable using the reliable-change method. On the first assessment 43/70 had normal quotients, 18 borderline, 5 mild, and 4 moderate intellectual disability, while 27/70 had no behavioral disorders, 17 had abnormal CBCL, and 26 patients had clear signs of attention deficits despite normal CBCL. The remaining seven were untestable. The mean total intelligence quotient change in the cohort was -2.99 points (SD: 12.29). Stable results on TIQ were found in 63% of the paired assessments. A third of the consecutive cognitive assessments showed a difference of more than 11 points with changes up to 42 points. Boys with no behavioral/attention disorder had smaller changes than those with attention (p = 0.007) and behavioral disorders (p = 0.002). Changes in IQ may occur in Duchenne and are likely to be associated with behavioral or attention deficits.

Language Development in Preschool Duchenne Muscular Dystrophy Boys.

BACKGROUND: the present study aims to assess language in preschool-aged Duchenne muscular dystrophy (DMD) boys with normal cognitive quotients, and to establish whether language difficulties are related to attentional aspects or to the involvement of brain dystrophin isoforms. METHODS: 20 children aged between 48 and 72 months were assessed with language and attention assessments for preschool children. Nine had a mutation upstream of exon 44, five between 44 and 51, four between 51 and 63, and two after exon 63. A control group comprising 20 age-matched boys with a speech language disorder and normal IQ were also used. RESULTS: lexical and syntactic comprehension and denomination were normal in 90% of the boys with Duchenne, while the articulation and repetition of long words, and sentence repetition frequently showed abnormal results (80%). Abnormal results were also found in tests assessing selective and sustained auditory attention. Language difficulties were less frequent in patients with mutations not involving isoforms Dp140 and Dp71. The profile in Duchenne boys was different form the one observed in SLI with no cognitive impairment. CONCLUSION: The results of our observational cross-sectional study suggest that early language abilities are frequently abnormal in preschool Duchenne boys and should be assessed regardless of their global neurodevelopmental quotient.

Age, corticosteroid treatment and site of mutations affect motor functional changes in young boys with Duchenne Muscular Dystrophy.

The aim of this study was to establish the possible effect of age, corticosteroid treatment and brain dystrophin involvement on motor function in young boys affected by Duchenne Muscular Dystrophy who were assessed using the North Star Ambulatory Assessment between the age of 4 and 7 years. The study includes 951 North Star assessments from 226 patients. Patients were subdivided according to age, to the site of mutation and therefore to the involvement of different brain dystrophin isoforms and to corticosteroids duration. There was a difference in the maximum North Star score achieved among patients with different brain dystrophin isoforms (p = 0.007). Patients with the involvement of Dp427, Dp140 and Dp71, had lower maximum NSAA scores when compared to those with involvement of Dp427 and Dp140 or of Dp427 only. The difference in the age when the maximum score was achieved in the different subgroups did not reach statistical significance. Using a linear regression model on all assessments we found that each of the three variables, age, site of mutation and corticosteroid treatment had an influence on the NSAA values and their progression over time. A second analysis, looking at 12-month changes showed that within this time interval the magnitude of changes was related to corticosteroid treatment but not to site of mutation. Our findings suggest that each of the considered variables appear to play a role in the progression of North Star scores in patients between the age of 4 and 7 years and that these should be carefully considered in the trial design of boys in this age range.

Body mass index in type 2 spinal muscular atrophy: a longitudinal study.

The aim of this retrospective study was to review body mass index (BMI) in a large cohort of Italian pediatric type 2 spinal muscular atrophy (SMA) patients, aged between 0 and 20 years and to establish possible differences in relation to a number of variables such as ventilation, motor function, and survival motor neuron 2 gene copies. Cross-sectional data were collected from 102 patients for a total of 344 visits. Standard growth charts for height and weight were used as reference, with age adjusted BMI calculated using the Center for Disease and Prevention Children's BMI Tool. In the 344 visits, weight ranged between 3.90 and 83 kg, and the BMI between 8.4 and 31.6 with a BMI/age z-scores < - 2SD present in 28% and BMI/age z-scores > + 2SD in 9% of the measurements. The BMI/age z-scores were relatively stable < 5 years of age with an increasing number of patients < - 2SD after the age of 5, and a wider range of BMI/age z-scores after the age of 13. A difference on the BMI/age z-scores was found among the different age subgroups (< 5, 5-12, ≥ 13 years). A multivariate analysis in 58 patients with longitudinal assessments showed that baseline BMI/age z-scores and gender were significantly contributing to the changes while other variables were not. CONCLUSION: Our results confirm that careful surveillance of weight and BMI/age z-scores is needed in type 2 SMA. Further studies, including assessments of chewing and swallowing and of lean/fat body mass, will help to better understand the possible mechanisms underlying weight issues. WHAT IS KNOWN: • Feeding difficulties have been reported in a few studies and were invariably found in patients with type 1 SMA. • Type 2 SMA patients often have low BMI with a relevant number of patients requiring tube feeding. WHAT IS NEW: • Reduction in BMI/age z-score overtime appeared to depend on baseline BMI/age z-score and gender. • Patients with a low BMI/age z-score were at higher risk of developing further reduction.

Age related treatment effect in type II Spinal Muscular Atrophy pediatric patients treated with nusinersen.

Previous natural history studies suggest that type II SMA patients remain stable over one year but show some progression over two years. Since nusinersen approval, there has been increasing attention to identify more specific age-related changes. The aim of the study was to establish 12-month changes in a cohort of pediatric type II SMA treated with nusinersen and to establish possible patterns of treatment effect in relation to different variables such as age, baseline value and SMN2 copy number. The Hammersmith Functional Motor Scale Expanded and the Revised Upper Limb Module were performed at T0 and 12 months after treatment (T12). Data in treated patients were compared to available data in untreated patients collected by the same evaluators.Seventy-seven patients of age between 2.64 and 17.88 years (mean:7.47, SD:3.79) were included. On t-test there was an improvement, with increased mean scores between T0 and T12 on both scales (p < 0.001). Using multivariate linear regression analysis, age and baseline scores were predictive of changes on both scales (p < 0.05) while SMN2 copy number was not. Differences were also found between study cohort and untreated data on both scales (p < 0.001). At 12 months, an increase in scores was observed in all the age subgroups at variance with natural history data. Our real-world data confirm the treatment effect of nusinersen in pediatric type II SMA patients and that the data interpretation should take into account different variables. These data confirm and expand the ones already reported in the Cherish study.

Early Gross Motor Milestones in Duchenne Muscular Dystrophy.

BACKGROUND: Over the last few years there has been increasing attention to detect early signs of impairment in young Duchenne muscular dystrophy boys but less has been reported on whether the delay may also affect the very early aspects of motor development, such as gross motor milestones. OBJECTIVE: The aim of this study was to retrospectively assess the age when early motor milestones were achieved in Duchenne muscular dystrophy. METHODS: The study is a retrospective analysis of data collected as part of a larger natural history project. Information on past medical history, collected at the time the boys were seen for the first time, were recorded and re available on clinical notes and on electronic CRF. RESULTS: Data were collected in 134 DMD boys. Sitting was achieved at 7.04 months. The % of DMD boys not achieving sitting by 9.4 months was 10%, ranging from 2% in the boys with mutations before exon 44 to 33% in those beyond exon 63. Walking was achieved at a mean age of 16.35 months. The % of DMD boys not achieving independent walking by 18 months was 17%, ranging from 9% in the boys with mutations between 44 and 51 to 42% in those beyond exon 63. CONCLUSIONS: Our results showed that the risk of a delay in sitting and walking was increasingly high in patients with mutations predictive of the involvement of different brain dystrophin isoforms.

Oral and Swallowing Abilities Tool (OrSAT) for Type 1 SMA Patients: Development of a New Module.

We describe the development of a new tool specifically designed to record oral abilities, swallowing and, more generally, feeding in young type 1 SMA patients, to be used during the first 24 months of life.The tool is composed by a checklist and a separate section summarizing the functional abilities into levels of feeding/swallowing impairment. The checklist includes 12 questions assessing aspects thought to be clinically meaningful for a type 1 SMA population and developmentally appropriate for infants during the first months of life. Each item is graded with a score of 0 or 1, depending on the child's ability to perform the activity. As some items are age-dependent, the number of items to be used, and therefore the maximum score, changes with increasing age. The levels of feeding/swallowing impairment include four levels that can be identified using easily identifiable clinical criteria.In an attempt to validate the tool in an untreated population we applied it to 24 type 1 SMA patients (age range: 2.3-24.1 months, mean: 10.8) in whom the same information collected by the new tool had been previously recorded using a less-structured format.When patients were classified in three groups according to the Dubowitz decimal classification, there was a significant difference both at baseline and at follow-up (p < 0.001). The items assessing fatigue during the nursing sessions were the most frequently impaired even in infants who did not have any other obvious clinical sign of swallowing difficulties.

The nonsense mutation stop+4 model correlates with motor changes in Duchenne muscular dystrophy.

The aim was to assess 3-year longitudinal data using 6MWT in 26 ambulant boys affected by DMD carrying nonsense mutations and to compare their results to other small mutations. We also wished to establish, within the nonsense mutations group, patterns of change according to several variables. Patients with nonsense mutations were categorized according to the stop codon type newly created by the mutation and also including the adjacent 5' (upstream) and 3' (downstream) nucleotides. No significant difference was found between nonsense mutations and other small mutations (p > 0.05) on the 6MWT. Within the nonsense mutations group, there was no difference in 6MWT when the patients were subdivided according to: Type of stop codon, frame status of exons involved, protein domain affected. In contrast, there was a difference when the stop codon together with the 3' adjacent nucleotide ("stop+4 model") was considered (p < 0.05) with patients with stop codon TGA and 3' adjacent nucleotide G (TGAG) having a more rapid decline. Our finding suggest that the stop+4 model may help in predicting functional changes. This data will be useful at the time of interpreting the long term follow up of patients treated with Ataluren that are becoming increasingly available.

Type I SMA "new natural history": long-term data in nusinersen-treated patients.

OBJECTIVE: The aim of this paper was to report the 2-year follow-up in type I patients treated with Nusinersen and to assess whether possible changes in motor function are related to the subtype, age, or SMN2 copy number. METHODS: Sixty-eight patients, with ages ranging from 0.20 to 15.92 years (mean: 3.96; standard deviation: +3.90) were enrolled in the study. All patients were assessed using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) and the developmental section of the Hammersmith Infant Neurological Examination (HINE-2) at the time they started treatment and 12 and 24 months after that. RESULTS: For both CHOP and HINE-2 repeated measures analysis of variance showed a significant difference (P < 0.001) between baseline and 12 months, 12 months and 24 months, and baseline and 24-month scores for the whole group. When age subgroups (<210 days, <2 years, 2-4 years, 5-11 years, 12-18 years) were considered, on the CHOP INTEND the difference was significant between baseline and 24 months in all age subgroups. On the HINE-2, the difference between baseline and 24 months was significant in all the subgroups before the age of 4 years. Age was predictive of changes on both scales (P < 0.05), whereas SMN2 copy number and decimal classification were not. INTERPRETATION: Our results suggest that some improvement of motor function can be observed even after the first year of treatment. This is more obvious in the infants treated in the first 2 years but some improvement can also be found in older children.

Sleep Disorders in Autism Spectrum Disorder Pre-School Children: An Evaluation Using the Sleep Disturbance Scale for Children.

Background and Objectives: Sleep disorders are common in children with Autism Spectrum Disorder (ASD). The aims of this study were to describe the incidence and characteristics of sleep disorders using a questionnaire completed by the caregiver in a sample of preschool-aged children with ASD and to identify possible differences in a control group of peers. Materials and Methods: Sleep disorders were investigated with the Sleep Disturbance Scale for Children (SDSC) in a population of pre-school-aged (3-5 years) ASD children and in a control group. The Autism Diagnostic Observation Schedule-second ed. (ADOS-2) was further used to assess autism symptom severity. A total of 84 children (69 males; mean age 3.9 ± 0.8 years) with a diagnosis of ASD and 84 healthy controls (65 males; mean age of 3.7 ± 0.8 years) that were matched for age and sex were enrolled. Results: ASD children reported significantly higher (pathological) scores than the control group on the SDSC total scores and in some of the factor scores, such as Difficulty in Initiating and Maintaining Sleep (DIMS), disorders of excessive somnolence (DOES), and sleep hyperhidrosis. A total of 18% of ASD children had a pathological SDSC total T-score, and 46% had an abnormal score on at least one sleep factor; DIMS, parasomnias, and DOES showed the highest rates among the sleep factors. Younger children (3 years) reported higher scores in DIMS and sleep hyperhidrosis than older ones (4 and 5 years). No specific correlation was found between ADOS-2 and SDSC scores. Conclusions: Pre-school children with ASD showed a high incidence of sleep disorders with different distributions of specific sleep factors according to their age. We suggest a screening assessment of sleep disorders using the SDSC in these children with a more in-depth evaluation for those reporting pathological scores on the questionnaire.

Multicenter prospective longitudinal study in 34 patients with Dravet syndrome: Neuropsychological development in the first six years of life.

The objective of this study was to identify developmental trajectories of developmental/behavioral phenotypes and possibly their relationship to epilepsy and genotype by analyzing developmental and behavioral features collected prospectively and longitudinally in a cohort of patients with Dravet syndrome (DS). Thirty-four patients from seven Italian tertiary pediatric neurology centers were enrolled in the study. All patients were examined for the SCN1A gene mutation and prospectively assessed from the first years of life with repeated full clinical observations including neurological and developmental examinations. Subjects were found to follow three neurodevelopmental trajectories. In the first group (16 patients), an initial and usually mild decline was observed between the second and the third year of life, specifically concerning visuomotor abilities, later progressing towards global involvement of all abilities. The second group (12 patients) showed an earlier onset of global developmental impairment, progressing towards a generally worse outcome. The third group of only two patients ended up with a normal neurodevelopmental quotient, but with behavioral and linguistic problems. The remaining four patients were not classifiable due to a lack of critical assessments just before developmental decline. The neurodevelopmental trajectories described in this study suggest a differential contribution of neurobiological and genetic factors. The profile of the first group, which included the largest fraction of patients, suggests that in the initial phase of the disease, visuomotor defects might play a major role in determining developmental decline. Early diagnosis of milder cases with initial visuomotor impairment may therefore provide new tools for a more accurate habilitation strategy.

Cortical Thickness and Clinical Findings in Prescholar Children With Autism Spectrum Disorder.

The term autism spectrum disorder (ASD) includes a wide variability of clinical presentation, and this clinical heterogeneity seems to reflect a still unclear multifactorial etiopathogenesis, encompassing different genetic risk factors and susceptibility to environmental factors. Several studies and many theories recognize as mechanisms of autism a disruption of brain development and maturation time course, suggesting the existence of common neurobiological substrates, such as defective synaptic structure and aberrant brain connectivity. Magnetic resonance imaging (MRI) plays an important role in both assessment of region-specific structural changes and quantification of specific alterations in gray or white matter, which could lead to the identification of an MRI biomarker. In this study, we performed measurement of cortical thickness in a selected well-known group of preschool ASD subjects with the aim of finding correlation between cortical metrics and clinical scores to understand the underlying mechanism of symptoms and to support early clinical diagnosis. Our results confirm that recent brain MRI techniques combined with clinical data can provide some useful information in defining the cerebral regions involved in ASD although large sample studies with homogeneous analytical and multisite approaches are needed.

Respiratory function and therapeutic expectations in DMD: families experience and perspective.

OBJECTIVE: The aim of this study was to use a structured questionnaire in a large cohort of Duchenne Muscular Dystrophy (DMD) patients to assess caregivers and patients views on respiratory function and to establish if their responses were related to the patients' age or level of functional impairment. METHODS: Questionnaires were administered to caregivers in 205 DMD patients of age between 3 and 36 years (115 ambulant, 90 non-ambulant), and to 64 DMD patients (3 ambulant, 61 non-ambulant) older than 18 years, subdivided into groups according to age, FVC, ambulatory and ventilatory status. RESULTS: Some differences were found in relation to FVC % values (p = 0.014), ambulatory (p = 0.043) and ventilatory status (p = 0.014). Nearly half of the caregivers expected deterioration over the next years, with the perspective of deterioration more often reported by caregivers of non-ambulant (p = 0.018) and ventilated patients (p = 0.004). Caregivers appeared to be aware of the relevance of respiratory function on quality of life (84%) showing willingness to enter possible clinical trials if these were aiming to stabilize the progression of respiratory function with a very high number of positive responses across the spectrum of age, FVC, ambulatory and ventilatory status. The boys older than 18 years showed similar results. CONCLUSIONS: Our study showed that the concern for respiratory function increases with age and with the reduction of FVC or the need for ventilation, but the need for intervention was acknowledged across the whole spectrum of age and functional status.

Age and baseline values predict 12 and 24-month functional changes in type 2 SMA.

The aim of this retrospective study was to establish the range of functional changes at 12 and 24-month in 267 type 2 Spinal Muscular Atrophy (SMA) patients with multiple assessments. We included 652 Hammersmith Functional Motor Scale Expanded (HFMSE) assessments at 12 month- and 305 at 24 month- intervals. The cohort was subdivided by functional level, Survival of Motor Neuron copy number and age. Stable scores (± 2 points) were found in 68% at 12 months and in 55% at 24 months. A decrease ≥2 points was found in 21% at 12 months and in 35% at 24 months. An increase ≥2 points was found in 11% at 12 months and 9.5% at 24 months. The risk of losing ≥2 points increased with age and HFMSE score at baseline both at 12 and 24-month. For each additional HFMSE point at baseline, the relative risk of a >2 point decline at 12 months increases by 5% before age 5 years (p = 0.023), by 8% between 5 and 13 (p<0.001) and by 26% after 13 years (p = 0.003). The combination of age and HFMSE scores at baseline increased the ability to predict progression in type 2 SMA.

Clinical Variability in Spinal Muscular Atrophy Type III.

OBJECTIVE: We report natural history data in a large cohort of 199 patients with spinal muscular atrophy (SMA) type III assessed using the Hammersmith Functional Motor Scale Expanded (HFMSE). The aim of the study was to establish the annual rate and possible patterns of progression according to a number of variables, such as age of onset, age at assessment, SMN2 copy number, and functional status. METHODS: HFMSE longitudinal changes were assessed using piecewise linear mixed-effects models. The dependency in the data due to repeated measures was accounted for by a random intercept per individual and an unstructured covariance R matrix was used as correlation structure. An additional descriptive analysis was performed for 123 patients, for a total of 375 12-month assessments. RESULTS: A break point at age 7 years was set for the whole cohort and for SMA IIIA and IIIB. Age, SMA type, and ambulatory status were significantly associated with changes in mean HFMSE score, whereas gender and SMN2 copy number were not. The increase in response before the break point of age 7 years is significant only for SMA IIIA (ß = 1.79, p < 0.0001). After the break point, the change in the rate of HFMSE score significantly decrease for both SMA IIIA (ß = -1.15, p < 0.0001) and IIIB (ß = -0.69, p = 0.002). INTERPRETATION: Our findings contribute to the understanding of the natural history of SMA type III and will be helpful in the interpretation of the real-world data of patients treated with commercially available drugs. ANN NEUROL 2020;88:1109-1117.

Gain and loss of abilities in type II SMA: A 12-month natural history study.

The advent of clinical trials in spinal muscular atrophy (SMA) has highlighted the need to define patterns of progression using functional scales. It has recently been suggested that the analysis of abilities gained or lost applied to functional scales better reflects meaningful changes. We defined as "gain" a positive change between scores from 0 to either 1 or 2 and as "loss" a negative change from either 2 or 1 to 0. The aim of this study was to describe, over 12 months, which abilities on the Hammersmith Functional Motor Scale Expanded (HFMSE) were more frequently lost or gained in patients with SMA II. The cohort included 614 12-month assessments from 243 patients (age range: 30 months - 63 years; mean 9.94, SD ±7.91). The peak of abilities gained occurred before the age of 5 years while the highest number of lost abilities was found in the group 5-13 years. A correlation between the HFMSE baseline score and the ordinal number of the items was found for both lost (p<0.001) or gained (p<0.001) activities. No correlation was found with SMN2 copy number. These findings will have implications for clinical trial design and for the interpretation of real-world data using new therapeutic approaches.

Early visual and neuro-development in preterm infants with and without retinopathy.

BACKGROUND: Retinopathy of prematurity (ROP) is often associated with visual impairment and multiple developmental disabilities. AIMS: As most of the previous studies include infants with brain lesions, that can determine visual impairment per se, a cohort of low neurological risk preterm infants without ROP and with various degree of severity of ROP was assessed in order to establish visual and neurodevelopmental outcome. STUDY DESIGN: Preterm infants born at <31 weeks gestation, without major brain lesions, underwent visual function assessment at 1 year corrected age and neurodevelopmental assessment at 2 years corrected age. SUBJECTS: One hundred and five infants were included in the study: 42 infants did not develop ROP, 7 reached stage 1 in zone 2 ROP, 37 reached prethreshold (untreated) type 2 ROP. The remaining 19 infants were classified as type 1 ROP. OUTCOME MEASURES: Visual function (including fixing, tracking, visual acuity, visual field, attention at distance and nystagmus) were assessed at 12 months corrected age and Griffiths Scales at 2 years corrected age. RESULTS: The severity of ROP was strongly correlated (p < 0.001) with both visual function at 1 year and neurodevelopment at 2 years. Similarly, the presence of nystagmus was also strongly correlated with visual and neurodevelopmental sequelae. CONCLUSIONS: Infants with no or milder retinopathy showed normal visual function at 1 year and neurodevelopment at 2 years. Infants who underwent treatment more frequently showed abnormal results on several aspects of visual function. Presence of nystagmus appeared to increase the risk for abnormal visual function and neurodevelopmental outcome.

Ultrasound assessment of diaphragmatic function in type 1 spinal muscular atrophy.

OBJECTIVE: To investigate ultrasound features of diaphragm motion and function in type 1 spinal muscular atrophy (SMA-1) patients. DESIGN: Prospective study. PATIENTS: The study cohort included SMA-1 children younger than 18-year-old. Control subjects included type 2 and type 3 SMA and other neuromuscular disorders younger than 18-year-old. METHODOLOGY: Diaphragm ultrasound evaluating diaphragmatic excursion, speed of diaphragmatic contraction, duration of the respiratory cycle, inspiratory/expiratory relationship, end-inspiratory and -expiratory thickness, thickening fraction, and pattern of contractility. The interrater reliability for each variable was established by calculation of Cohen's k coefficient. RESULTS: Twenty-three SMA-1 patients and 12 controls were evaluated. Diaphragm ultrasound values were within normal ranges in all study cohort patients and no difference was found with controls. There was a gradient of diaphragm function with SMA 1.9 subgroup having the best and SMA 1.1 having the worst parameters, particularly in end-inspiratory thickness and diaphragmatic excursion (P = .031 and P = .041, respectively). Seventy-four percent of SMA-1 patients had a dysmotility pattern of diaphragm contraction, mostly represented in SMA 1.9 subgroup (P = .001). This pattern was observed in 92.8% of children on noninvasive ventilation (NIV) for less than 16 hours/d of and in 20% patients with invasive ventilation or NIV for more than 16 hours/d (P = .027). The dysmotility pattern was never observed in the control group. The levels of interobserver agreement were high for "diaphragm irregularities," "inspiratory/expiratory relationship," and "diaphragm thickness," and good for the other variables. CONCLUSIONS: Ultrasound can be used to evaluate diaphragm function and contractility in SMA-1 children, providing additional information to the clinical examination and functional respiratory tests, describing a characteristic contractility pattern in these patients. Longitudinal studies are needed to understand the impact of diaphragm dysmotility and other parameters on long-term outcome in SMA-1 patients.

Longitudinal natural history of type I spinal muscular atrophy: a critical review.

BACKGROUND: The advent of new therapies in spinal muscular atrophy (SMA) has highlighted the need to have natural history data for comparison. Natural history studies using structured assessments in type I however are very limited. We identified and reviewed all the existing longitudinal history data in infants with type I SMA first assessed before the age of 7 months with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND). MAIN TEXT: Three longitudinal natural history studies, two performed in the United States and one in Italy, were identified. The different study design of these three studies made it possible for the cumulative dataset to include the full spectrum of severity; from infants with neonatal onset to those with a milder phenotype that were not always included in the individual natural history studies. The cumulative analysis confirmed that, even in a larger cohort, there was never an improvement on the CHOP INTEND over time. This was true for all the infants, irrespective of their age or baseline CHOP INTEND scores. Infants with neonatal onset had low CHOP INTEND scores and a fast decline. The relatively large number of patients allowed us to calculate the rate of progression in subgroups identified according to SMN2 copy number and baseline CHOP INTEND scores. CONCLUSION: A detailed understanding of the existing data is important, as it will be difficult to acquire new systematic longitudinal history data because of the availability of disease modifying therapies. The cumulative findings in this review help to better understand the variability of natural history data in untreated patients and will be of use for comparison to the real world patients treated with the recently approved therapies that have shown encouraging results in clinical trials.