M M Ryan

The Royal Children's Hospital, Melbourne, Victoria, Australia

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Publications (5)25.67 Total impact

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    ABSTRACT: Background/Objectives:Nutritional issues that are associated with Duchenne muscular dystrophy (DMD) remain poorly understood. The aim of this analysis was to describe and explore longitudinal observations of body mass index (BMI) in a cohort of children with DMD.Subjects/Methods:Anthropometric and clinical characteristics were collected retrospectively and longitudinally for boys with DMD seen in two large neuromuscular clinics. BMI Z-scores were determined using the Centers for Disease Control and Prevention reference values for children (2000).Results:Medical records (n=193) were examined from which 75% were included for analysis. The mean age of the cohort at the time of data collection was 11.9 years, with 72% of patients currently or previously using steroids. The highest prevalence of obesity based on the BMI Z-score was 50% at the age of 10 years. Longitudinally, BMI Z-scores from the age of 2 to 12 years plot approximately one s.d. above the mean, after which there is a marked and progressive decline. BMI gainers were identified for whom BMI Z-score increased by 1.65 units compared with the 0.09 units in non-gainers. BMI gainers were younger when they had their first BMI measurement (5.9 vs 7.2 years), and this measure was significantly lower compared with the non-gainers (BMI Z-score: 0.04 vs 1.17). In this cohort, BMI was associated with age, ambulatory status and lung function.Conclusions:This study demonstrates that boys with DMD using steroid therapy experience shifts in BMI. A declining BMI appears to be associated with increasing age. Interpretation of growth patterns is limited here by a lack of normative growth references in DMD.European Journal of Clinical Nutrition advance online publication, 14 May 2014; doi:10.1038/ejcn.2014.93.
    European journal of clinical nutrition 05/2014; 68(8). DOI:10.1038/ejcn.2014.93 · 2.95 Impact Factor
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    ABSTRACT: Background Carpal tunnel syndrome is rare in children but is a recognised complication of the mucopolysaccharidoses. Clinicians should have a low threshold of suspicion for carpal tunnel syndrome in this group as symptoms may be atypical or minimal, especially in those with intellectual disabilities secondary to mucopolysaccharidoses. If untreated, carpal tunnel syndrome can cause significant, potentially permanent loss of hand function. We present findings in 11 children with mucopolysaccharidoses and suspected median neuropathies at the wrist, and propose guidelines for screening for carpal tunnel syndrome in children with these disorders. Methods Clinical and electrodiagnostic data of 11 children with confirmed mucopolysaccharidoses by enzymatic ± molecular testing, who were suspected on clinical grounds to have carpal tunnel syndrome, was reviewed. All subjects underwent motor and sensory conduction studies of bilateral median and ulnar nerves. The presence of carpal tunnel syndrome and its severity was determined. Subsequent details of intervention (s) and recurrence were noted. Results Three children had Hurler syndrome (MPS I), five had Hunter syndrome (MPS II), one had Sanfilippo syndrome (MPS III) and two had Morquio syndrome (MPS IV). Seven had motor and three sensory features referable to median nerve compression. Nine of the eleven children (2/3 with MPS I, 5/5 with MPS II, 0/1 with MPS III, 2/2 with MPS IV) had median neuropathies at the wrist (eight bilateral, one unilateral), which were mild in three, moderate in five, and severe in one. Three children presented with symptoms at 5 years age. Six underwent median nerve decompression. Four of these had recurrent symptoms several years after surgery. Recurrent carpal tunnel syndrome was confirmed on nerve conduction studies in two cases. To the best of our knowledge, this is the first report of carpal tunnel syndrome in MPS IV. Conclusion Some children with mucopolysaccharidoses experience early development of at least moderately severe carpal tunnel syndrome. We recommend screening for median neuropathies at the wrist from age 5 years for children with mucopolysaccharidoses, particularly types I, II and IV, regardless of whether they are symptomatic or asymptomatic of carpal tunnel syndrome and of the treatment received for their mucopolysaccharidosis.
    Clinical Neurophysiology 04/2014; 125(4):e4–e5. DOI:10.1016/j.clinph.2013.10.033 · 2.98 Impact Factor
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    ABSTRACT: There is considerable variation in the rate of disease progression and response to steroid therapy in males with Duchenne muscular dystrophy (DMD). Genetic influences may explain at least part of this heterogeneity. This retrospective case series explored the relationship between dystrophin gene mutations (DMD) and age at loss of ambulation (LOA). Medical histories (n = 144) were examined from two Australian neuromuscular clinics. Data were collected on clinical characteristics including DMD mutation type and location, age at LOA, anthropometry, lung function and steroid use. The relationship between age at LOA and genetic and clinical characteristics including age at chart review, duration of steroid treatment, and BMI z-score was explored via multiple regression analysis. Significant independent variables were also entered in a logistic regression to predict LOA <10 years of age. The mean (±SD) age of the cohort was 11.9 ± 4.0 years, and 51% of boys had lost the ability to walk independently. Mutation type and duration of steroid treatment were significant independent predictors of LOA <10 years in a logistic model explaining 31.2% of the variance in age of LOA. Boys with deletions in the dystrophin gene were six times more likely to stop walking before age 10 compared to boys with duplications, point or unknown mutations. This was reflected in the mean age at LOA in boys with deletions versus other mutations (9.30 ± 1.60 vs 10.97 ± 2.03 years, respectively, p < 0.0005). A longer duration of steroid therapy was associated with a reduction in risk of LOA <10 years. BMI had no relationship with age at LOA. Whilst the negative effects of steroid treatment such as weight gain and decreased bone health need to be considered, early introduction of steroids may provide some functional benefits, especially to boys with a documented deletion in DMD gene.
    Neuromuscular Disorders 10/2012; 22(9-10):835. DOI:10.1016/j.nmd.2012.06.111 · 3.13 Impact Factor
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    ABSTRACT: To perform a double-blind, randomized study comparing efficacy and safety of daily and weekend prednisone in boys with Duchenne muscular dystrophy (DMD). A total of 64 boys with DMD who were between 4 and 10 years of age were randomized at 1 of 12 centers of the Cooperative International Neuromuscular Research Group. Efficacy and safety of 2 prednisone schedules (daily 0.75 mg/kg/day and weekend 10 mg/kg/wk) were evaluated over 12 months. Equivalence was met for weekend and daily dosing of prednisone for the primary outcomes of quantitative muscle testing (QMT) arm score and QMT leg score. Secondary strength scores for QMT elbow flexors also showed equivalence between the 2 treatment groups. Overall side effect profiles of height and weight, bone density, cataract formation, blood pressure, and behavior, analyzed at 12 months, did not differ between weekend and daily dosing of prednisone. Weekend dosing of prednisone is equally beneficial to the standard daily dosing of prednisone. Analysis of side effect profiles demonstrated overall tolerability of both dosing regimens. This study provides Class I evidence that weekend prednisone dosing is as safe and effective as daily prednisone in preserving muscle strength and preventing body mass index increases in boys with DMD over a 12-month period.
    Neurology 08/2011; 77(5):444-52. DOI:10.1212/WNL.0b013e318227b164 · 8.30 Impact Factor
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    ABSTRACT: The incidence, cause, and prognosis of sciatic neuropathy in children is not well understood. We report our 30-year experience of 53 patients with pediatric sciatic neuropathies (SN). Prospective review of the history, physical examination, electrophysiologic findings, and clinical course of children with SN. The etiology of SN injury was varied and included trauma (13), iatrogenic causes (13) (8 orthopedic surgeries and 5 miscellaneous surgeries), prolonged extrinsic compression and immobilization (6), tumors (7), vascular (5), idiopathic and progressive (4), infantile and nonprogressive (2), and unknown, presumed postviral (3). Electrophysiologic studies demonstrated abnormalities in motor conduction studies of the peroneal nerve in 44/53 (83%) or tibial nerve in 35/51 (67%). Sensory conduction studies were abnormal in sural nerve in 34 of 43 cases (79%), and superficial peroneal nerves in 15/25 (60%). Needle EMG was abnormal in peroneal innervated muscles in all subjects, in tibial nerve innervated muscles in 43/51 (84%), and in the hamstrings in 18/29 (62%). Prognosis for recovery was variable and depended on the etiology and the severity of the nerve injury. SN is an uncommon mononeuropathy in children. The causes of SN are varied in children compared to adults. Electrophysiologic studies in children may be limited by poor tolerance but play an important role in establishing the diagnosis.
    Neurology 03/2011; 76(11):976-80. DOI:10.1212/WNL.0b013e3182104394 · 8.30 Impact Factor