title: Slow, progressive myopathy in neonatally treated patients with infantile-onset Pompe disease: a muscle magnetic resonance imaging study.
abstract: Patients with infantile-onset Pompe disease (IOPD) can be identified through newborn screening, and the subsequent immediate initiation of enzyme replacement therapy significantly improves the prognosis of these patients. However, they still present residual muscle weakness. In the present study, we used longitudinal muscle magnetic resonance imaging (MRI) to determine whether this condition is progressive.
  
  
  
  A cohort of classic IOPD patients who were diagnosed through newborn screening were treated with recombinant human acid α-glucosidase (rhGAA) and followed prospectively from birth. The trunk (and abdominal wall), pelvis and upper thighs were scanned for muscle MRI every 2-3 years. Seven groups of muscles were individually scored from 0 to 4 based on the extent of their involvement, and the sum was correlated to the clinical manifestations.
  
  
  
  Twenty-four MRI scans from a total of 12 neonatally treated IOPD patients were analyzed in the present study. The median age at the time of MRI scanning was 4.2 years (13 days to 9 years). High intensity over the quadriceps on T2-weighted and short-tau inversion recovery images was observed in all scans and was followed by a decrease in muscle mass. Trunk muscle involvement was slower, except in one patient who exhibited progressive psoas atrophy. Among the 10 patients for whom follow-up scans were repeated more than 2 years after the first scan, four patients (40 %) showed increased myopathy severity.
  
  
  
  This prospective muscle MRI study provides evidence for the occurrence of slow, progressive muscle damage in neonatally treated IOPD patients during childhood. New treatment strategies are necessary to improve outcomes in these patients.
authors.affiliation: Department of Radiology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Steven Shinn-Forng
authors.initials: SS
authors.lastname: Peng
authors.affiliation: Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan.|Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.|Department of Pediatrics, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wuh-Liang
authors.initials: WL
authors.lastname: Hwu
authors.affiliation: Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan.|Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.|Department of Pediatrics, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Ni-Chung
authors.initials: NC
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, College of Chinese Medicine, Taichung, Taiwan.
authors.forename: Fuu-Jen
authors.initials: FJ
authors.lastname: Tsai
authors.affiliation: Department of Pediatrics, Chi Mei Medical Center, Tainan, Taiwan.
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Tsai
authors.affiliation: Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan. chienyh@ntu.edu.tw.|Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. chienyh@ntu.edu.tw.|Department of Pediatrics, National Taiwan University College of Medicine, Taipei, Taiwan. chienyh@ntu.edu.tw.
authors.forename: Yin-Hsiu
authors.initials: YH
authors.lastname: Chien
mesh_terms: D002648:Child; D002675:Child, Preschool; D006009:Glycogen Storage Disease Type II / Q000150:complications* / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D009135:Muscular Diseases / Q000000981:diagnostic imaging* / Q000209:etiology*
keywords: Enzyme Replacement Therapy; Glycogen Storage Disease Type II; Magnetic Resonance Imaging; Neonatal Screening