Benefits of glucocorticoids in non-ambulant boys/men with Duchenne muscular dystrophy: A multicentric longitudinal study using the Performance of Upper Limb test.

The aim of this study was to establish the possible effect of glucocorticoid treatment on upper limb function in a cohort of 91 non-ambulant DMD boys and adults of age between 11 and 26 years. All 91 were assessed using the Performance of Upper Limb test. Forty-eight were still on glucocorticoid after loss of ambulation, 25 stopped steroids at the time they lost ambulation and 18 were GC naïve or had steroids while ambulant for less than a year. At baseline the total scores ranged between 0 and 74 (mean 41.20). The mean total scores were 47.92 in the glucocorticoid group, 36 in those who stopped at loss of ambulation and 30.5 in the naïve group (p < 0.001). The 12-month changes ranged between -20 and 4 (mean -4.4). The mean changes were -3.79 in the glucocorticoid group, -5.52 in those who stopped at loss of ambulation and -4.44 in the naïve group. This was more obvious in the patients between 12 and 18 years and at shoulder and elbow levels. Our findings suggest that continuing glucocorticoids throughout teenage years and adulthood after loss of ambulation appears to have a beneficial effect on upper limb function.

Prevalence of congenital muscular dystrophy in Italy: a population study.

OBJECTIVE: We provide a nationwide population study of patients with congenital muscular dystrophy in Italy. METHODS: Cases were ascertained from the databases in all the tertiary referral centers for pediatric neuromuscular disorders and from all the genetic diagnostic centers in which diagnostic tests for these forms are performed. RESULTS: The study includes 336 patients with a point prevalence of 0.563 per 100,000. Mutations were identified in 220 of the 336 (65.5%). The cohort was subdivided into diagnostic categories based on the most recent classifications on congenital muscular dystrophies. The most common forms were those with α-dystroglycan glycosylation deficiency (40.18%) followed by those with laminin α2 deficiency (24.11%) and collagen VI deficiency (20.24%). The forms of congenital muscular dystrophy related to mutations in SEPN1 and LMNA were less frequent (6.25% and 5.95%, respectively). CONCLUSIONS: Our study provides for the first time comprehensive epidemiologic information and point prevalence figures for each of the major diagnostic categories on a large cohort of congenital muscular dystrophies. The study also reflects the diagnostic progress in this field with an accurate classification of the cases according to the most recent gene discoveries.

Suitability of North Star Ambulatory Assessment in young boys with Duchenne muscular dystrophy.

The aim of this study was to establish the suitability of the North Star Ambulatory Assessment for use in young boys with Duchenne muscular dystrophy. We studied 147 typically developing and 144 boys affected by Duchenne muscular dystrophy between the ages of 3 and 5 years. More than 85% of the typically developing boys by the age of 4 years had full scores on all the items with total scores ≥33/34. Before the age of 4 years more than 15% of the typically developing boys did not achieve full scores on all the items. Some items, such as standing on one leg, showed significant improvement with age. In contrast, other activities were rarely achieved even in the older boys. Even if there was a progressive increase in scores with age, both total and individual item scores in Duchenne were still far from those obtained in the typically developing children of the same age. Our findings suggest that the North Star Ambulatory Assessment can be reliably used at least from the age of 4 years. Longitudinal natural history data studies are needed to assess possible changes over time and the possible effect of early steroids.

Cardiac function in types II and III spinal muscular atrophy: should we change standards of care?

OBJECTIVE: In the last years, there has been increasing evidence of cardiac involvement in spinal muscular atrophy (SMA). Autonomic dysfunction has been reported in animal models and in several patients with types I and III SMA, these findings raising the question whether heart rate should be routinely investigated in all SMA patients. The aim of our study was to detect possible signs of autonomic dysfunction and, more generally, of cardiac involvement in types II and III SMA. PATIENTS AND METHODS: We retrospectively reviewed 24-hour electrocardiography (ECG) in 157 types II and III SMA patients (age range, 2-74 years). Of them, 82 also had echocardiography. RESULTS: None of the patients had signs of bradycardia, atrial fibrillation, or the other previously reported rhythm disturbances regardless of the age at examination or the type of SMA. Echocardiography was also normal. There were no signs of congenital cardiac defects with the exception of one patient with a history of ventricular septal defects. CONCLUSIONS: Our results suggest that cardiac abnormalities are not common in type II and type III SMA. These findings provide no evidence to support a more accurate cardiac surveillance or changes in the existing standards of care.

6 Minute walk test in Duchenne MD patients with different mutations: 12 month changes.

OBJECTIVE: In the last few years some of the therapeutical approaches for Duchenne muscular dystrophy (DMD) are specifically targeting distinct groups of mutations, such as deletions eligible for skipping of individual exons. The aim of this observational study was to establish whether patients with distinct groups of mutations have different profiles of changes on the 6 minute walk test (6MWT) over a 12 month period. METHODS: The 6MWT was performed in 191 ambulant DMD boys at baseline and 12 months later. The results were analysed using a test for heterogeneity in order to establish possible differences among different types of mutations (deletions, duplications, point mutations) and among subgroups of deletions eligible to skip individual exons. RESULTS: At baseline the 6MWD ranged between 180 and 560,80 metres (mean 378,06, SD 74,13). The 12 month changes ranged between -325 and 175 (mean -10.8 meters, SD 69.2). Although boys with duplications had better results than those with the other types of mutations, the difference was not significant. Similarly, boys eligible for skipping of the exon 44 had better baseline results and less drastic changes than those eligible for skipping exon 45 or 53, but the difference was not significant. CONCLUSIONS: even if there are some differences among subgroups, the mean 12 month changes in each subgroup were all within a narrow Range: from the mean of the whole DMD cohort. This information will be of help at the time of designing clinical trials with small numbers of eligible patients.

Reliability of the Performance of Upper Limb assessment in Duchenne muscular dystrophy.

The Performance of Upper Limb was specifically designed to assess upper limb function in Duchenne muscular dystrophy. The aim of this study was to assess (1) a cohort of typically developing children from the age of 3years onwards in order to identify the age when the activities assessed in the individual items are consistently achieved, and (2) a cohort of 322 Duchenne children and young adults to establish the range of findings at different ages. We collected normative data for the scale validation on 277 typically developing subjects from 3 to 25years old. A full score was consistently achieved by the age of 5years. In the Duchenne cohort there was early involvement of the proximal muscles and a proximal to distal progressive involvement. The scale was capable of measuring small distal movements, related to activities of daily living, even in the oldest and weakest patients. Our data suggest that the assessment can be reliably used in both ambulant and non ambulant Duchenne patients in a multicentric setting and could therefore be considered as an outcome measure for future trials.

The 6 minute walk test and performance of upper limb in ambulant duchenne muscular dystrophy boys.

The Performance of Upper Limb (PUL) test was specifically developed for the assessment of upper limbs in Duchenne muscular dystrophy (DMD). The first published data have shown that early signs of involvement can also be found in ambulant DMD boys. The aim of this longitudinal Italian multicentric study was to evaluate the correlation between the 6 Minute Walk Test (6MWT) and the PUL in ambulant DMD boys. Both 6MWT and PUL were administered to 164 ambulant DMD boys of age between 5.0 and 16.17 years (mean 8.82). The 6 minute walk distance (6MWD) ranged between 118 and 557 (mean: 376.38, SD: 90.59). The PUL total scores ranged between 52 and 74 (mean: 70.74, SD: 4.66). The correlation between the two measures was 0.499. The scores on the PUL largely reflect the overall impairment observed on the 6MWT but the correlation was not linear. The use of the PUL appeared to be less relevant in the very strong patients with 6MWD above 400 meters, who, with few exceptions had near full scores. In patients with lower 6MWD the severity of upper limb involvement was more variable and could not always be predicted by the 6MWD value or by the use of steroids. Our results confirm that upper limb involvement can already be found in DMD boys even in the ambulant phase.

Development of the Performance of the Upper Limb module for Duchenne muscular dystrophy.

AIM: An international Clinical Outcomes Group consisting of clinicians, scientists, patient advocacy groups, and industries identified a need for a scale to measure motor performance of the upper limb. We report the steps leading to the development of the Performance of the Upper Limb (PUL), a tool specifically designed for assessing upper limb function in ambulant and non-ambulant patients with Duchenne muscular dystrophy (DMD). METHOD: The development of the PUL followed a number of steps, from the systematic review and a preliminary study exploring the suitability of the existing measures, to the application of a pilot version in a multicentric setting, with Rasch analysis of the preliminary results, leading to a revised pro forma. RESULTS: The PUL was specifically designed for DMD, with a conceptual framework reflecting the progression of weakness and natural history of functional decline in DMD. Modern psychometric methods were used to create a scale with robust internal reliability, validity, and hierarchical scalability; males with DMD and their families were involved iteratively throughout the process of the clinician-reported outcome assessment tool development to establish clinical meaningfulness and relevance of individual PUL items to activities of daily living. INTERPRETATION: The module was developed using innovative approaches and will be useful for designing clinical trials.

Early neurodevelopmental assessment in Duchenne muscular dystrophy.

The aim of this study was to assess neurodevelopmental profile in young boys affected by Duchenne muscular dystrophy and to establish the correlation between neurodevelopmental findings, and the type and site of mutations. A structured neurodevelopmental assessment (Griffiths Scale of Mental Development) was performed in 81 DMD boys before the age of four years (range: 7-47 months). The mean total DQ was 87 (SD 15.3). Borderline DQ (between 70 and 84) was found in 32% and DQ below 70 in 12.3% of the patients. Children with mutations upstream or in exon 44 had higher DQ than those with mutations downstream exon 44 which are associated with involvement of dystrophin isoforms expressed at high levels in brain. The difference was significant for total and individual subscale DQ with the exception of the locomotor subscale. Items, such as ability to run fast, or getting up from the floor consistently failed in all children, irrespective of the age or of the site of mutation. Our results help to understand the possible different mechanisms underlying the various aspects of neurodevelopmental delay, suggesting that the involvement of brain dystrophin isoforms may cause a delay in the maturation of coordination and dexterity.

24 month longitudinal data in ambulant boys with Duchenne muscular dystrophy.

OBJECTIVES: The aim of the study was i) to assess the spectrum of changes over 24 months in ambulant boys affected by Duchenne muscular dystrophy, ii) to establish the difference between the first and the second year results and iii) to identify possible early markers of loss of ambulation. METHODS: One hundred and thirteen patients (age range 4.1-17, mean 8.2) fulfilled the inclusion criteria, 67 of the 113 were on daily and 40 on intermittent steroids, while 6 were not on steroids. All were assessed using the 6 Minute Walk Test (6MWT), the North Star Ambulatory Assessment (NSAA) and timed test. RESULTS: On the 6MWT there was an average overall decline of -22.7 (SD 81.0) in the first year and of -64.7 (SD 123.1) in the second year. On the NSAA the average overall decline was of -1.86 (SD 4.21) in the first year and of -2.98 (SD 5.19) in the second year. Fourteen children lost ambulation, one in the first year and the other 13 in the second year of the study. A distance of at least 330 meters on the 6MWT, or a NSAA score of 18 at baseline reduced significantly the risk of losing ambulation within 2 years. CONCLUSIONS: These results can be of help at the time of using inclusion criteria for a study in ambulant patients in order to minimize the risk of patients who may lose ambulation within the time of the trial.

Muscle MRI in Becker muscular dystrophy.

The aim of this study was to evaluate pelvis and lower limb muscle MRI scans of 46 patients affected by Becker muscular dystrophy (BMD), subdivided according to disease severity, ranging from clinically asymptomatic patients to patients who had lost ambulation. We found a distinct pattern on muscle imaging characterized by prominent involvement of the gluteus maximus and medius, adductor magnus, biceps femoris long head, semimembranosus and vasti. This pattern was consistent in all the 25 symptomatic patients. Milder changes in the same muscles were found in 13 of the 21 asymptomatic cases. The other 8 asymptomatic patients had a normal scan. The severity of muscle involvement was significantly correlated with age. Our results suggest that a distinct pattern of muscle involvement can be detected in BMD. The early identification of muscle changes in a proportion of asymptomatic patients may be useful as an additional tool in the diagnostic workup.

A critical review of functional assessment tools for upper limbs in Duchenne muscular dystrophy.

The recent development of therapeutic approaches for Duchenne muscular dystrophy (DMD) has highlighted the need to identify clinical outcome measures for planned efficacy studies. Although several studies have reported the value of functional scales, timed tests, and measures of endurance aimed at ambulant individuals, less has been done to identify reliable measures of function in individuals who have lost ambulation. The aim of this paper is to provide a critical review of the existing literature on functional measures assessing upper extremity function in DMD. Four observer-rated, performance-based measures and four self-reported scales have been previously used in DMD. Each scale provides useful information but none reflects all the different levels of functional ability in activities of daily living observed in individuals with DMD at different ages.

Attention deficit hyperactivity disorder and cognitive function in Duchenne muscular dystrophy: phenotype-genotype correlation.

OBJECTIVES: To assess attention deficit hyperactivity disorder (ADHD) in boys affected by Duchenne muscular dystrophy (DMD) and to explore the relationship with cognitive abilities and genetic findings. STUDY DESIGN: Boys with DMD (n = 103; 4-17 years of age, mean: 12.6) were assessed using a cognitive test (Wechsler scales). Assessment of ADHD was based on the Diagnostic Statistical Manual, Fourth Edition, Text Revision criteria and on the long version of the Conners Parents and Teachers Rating Scales. RESULTS: ADHD was found in 33 of the 103 boys with DMD. Attention problems together with hyperactivity (17/33) or in isolation (15/33) were more frequent than hyperactivity alone, which was found in 1 patient. Intellectual disability (ID) was found in 27/103 (24.6%). Sixty-two of the 103 boys had no ID and no ADHD, 9 had ID but no ADHD, 14 had ADHD but no ID, and 18 had both. ADHD occurred more frequently in association with mutations predicted to affect Dp140 expression (exon 45-55) and in those with mutations predicted to affect all dystrophin product, including Dp71 (ie, those that have promoter region and specific first exon between exons 62 and 63 but were also relatively frequent). CONCLUSIONS: Our results suggest that ADHD is a frequent feature in DMD. The risk of ADHD appears to be higher in patients carrying mutations predicted to affect dystrophin isoforms expressed in the brain and are known to be associated with higher risk of cognitive impairment.

Fetal acetylcholine receptor inactivation syndrome and maternal myasthenia gravis: a case report.

Fetal acetylcholine receptor inactivation syndrome is a rare condition occurring in newborns of myasthenic mothers, characterized by bulbar and facial weakness after recovery from the generalized muscle weakness. Antibodies against fetal subunit of acetylcholine receptor seem to have a pathogenetic role leading to long-lasting injury in vulnerable muscle groups. We report a girl, born to a myasthenic mother, who presented with this peculiar phenotype associated with high titers of antibodies specific to the fetal acetylcholine receptor. Although the infant had partial clinical improvement she died prematurely of aspiration pneumonia. We believe that this is a rare but possibly unrecognized condition that should be considered in newborns with persistent myasthenic features even in asymptomatic mothers, and clinicians should consider supportive intervention to avoid fatal complications.

Assessing upper limb function in nonambulant SMA patients: development of a new module.

We report the development of a module specifically designed for assessing upper limb function in nonambulant SMA patients, including young children and those with severe contractures. The application of the module to a preschool cohort of 40 children (age 30-48 months) showed that all the items could be completed by 30 months. The module was also used in 45 nonambulant SMA patients (age 30 months to 27 years). Their scores were more variable than in the preschool cohort, ranging from 0 to 18. The magnitude of scores was not related to age (r=-0.19). The upper limb scores had a good correlation with the Hammersmith Functional Motor Scale, r=0.75, but the upper limb function did not always strictly follow the overall gross motor function. These findings suggest that even some of the very weak nonambulant children possess upper limb skills that can be measured.

Early visual assessment in preterm infants with and without brain lesions: correlation with visual and neurodevelopmental outcome at 12 months.

BACKGROUND: Several studies have reported the development of various aspects of visual function in infancy and early childhood in both preterm and term-born infants, but only a few studies have focused on the predictive power of neonatal visual findings in infants with brain lesions. AIMS: To explore visual findings at term age, and at 3 and 12 months corrected age in preterm infants (gestational age <33 weeks) with and without brain lesions; to compare the assessment at term age and at 12 months; and to assess the relationship between visual findings and neurodevelopmental outcome at 12 months. STUDY DESIGN: Cranial ultrasound scans (US) were classified in normal, mild or major abnormalities. One-hundred and forty-five infants were assessed with age specific tests for visual function at term age, and at 3 and 12 months. Neurodevelopmental assessment (Griffiths' Scales) was performed at 12 months. RESULTS: A good correlation was found between early and late visual assessment and neurodevelopment outcome. Of the 121 infants with normal neonatal visual assessment, 119 were also normal at 12 months and 116 had normal developmental quotient. Of the 24 infants with abnormal neonatal visual assessment, 12 were also abnormal at 12 months. All the false positives had normalised by 3 months. Of the 35 infants with major US abnormalities, 20 had normal and 15 abnormal scores on the neonatal assessment. At 1 year 17 had normal and 18 abnormal scores. CONCLUSION: A normal visual assessment at term age is a good predictor of normal visual and neurodevelopmental outcome at 12 months. An abnormal visual examination in the neonatal period was a less reliable prognostic indicator, infant should be reassessed at 3 months.

North Star Ambulatory Assessment, 6-minute walk test and timed items in ambulant boys with Duchenne muscular dystrophy.

The North Star Ambulatory Assessment is a functional scale specifically designed for ambulant boys affected by Duchenne muscular dystrophy (DMD). Recently the 6-minute walk test has also been used as an outcome measure in trials in DMD. The aim of our study was to assess a large cohort of ambulant boys affected by DMD using both North Star Assessment and 6-minute walk test. More specifically, we wished to establish the spectrum of findings for each measure and their correlation. This is a prospective multicentric study involving 10 centers. The cohort included 112 ambulant DMD boys of age ranging between 4.10 and 17 years (mean 8.18±2.3 DS). Ninety-one of the 112 were on steroids: 37/91 on intermittent and 54/91 on daily regimen. The scores on the North Star assessment ranged from 6/34 to 34/34. The distance on the 6-minute walk test ranged from 127 to 560.6 m. The time to walk 10 m was between 3 and 15 s. The time to rise from the floor ranged from 1 to 27.5 s. Some patients were unable to rise from the floor. As expected the results changed with age and were overall better in children treated with daily steroids. The North Star assessment had a moderate to good correlation with 6-minute walk test and with timed rising from floor but less with 10 m timed walk/run test. The 6-minute walk test in contrast had better correlation with 10 m timed walk/run test than with timed rising from floor. These findings suggest that a combination of these outcome measures can be effectively used in ambulant DMD boys and will provide information on different aspects of motor function, that may not be captured using a single measure.

Muscle magnetic resonance imaging involvement in muscular dystrophies with rigidity of the spine.

OBJECTIVE: The aim of the study was to evaluate whether the visual analysis of muscle magnetic resonance imaging scans can identify specific patterns of muscle involvement. METHODS: We assessed scans from 83 patients with muscle disorders characterized by rigidity of the spine secondary to mutations in 4 different genes. The conditions studied were rigid spine syndrome (SEPN1 defects), Bethlem myopathy, and Ullrich congenital muscular dystrophy, allelic disorders caused by Col6A1, Col6A2, and Col6A3 mutations, the autosomal dominant form of Emery-Dreifuss muscular dystrophy (LMNA defects) and calpain-deficient limb girdle muscular dystrophy (CAPN3 defects). The scans of 25 patients affected by other myopathies were also reviewed as a control group. The scans were compared with the previously described patterns. RESULTS: In 82% of the scans in the study group (68/83) the patterns were classified as "typical" of 1 of the 5 forms studied, and in 7 (8%) were consistent with 1 of the reported patterns but not entirely typical. With one exception, the patterns identified were always consistent with the appropriate genetic diagnosis. The remaining scans (9%) had only minimal changes and were uninformative. None of the scans of the 25 patients in the control group had patterns that could be classified as typical of the 5 forms examined. The sensitivity to detect selective patterns in relation to the genetic diagnosis was 0.9. INTERPRETATION: These findings suggest that muscle magnetic resonance imaging could be used in clinical practice as an additional tool in the differential diagnosis of muscle disorders with prominent spinal rigidity.