title: Electromyographic findings in 37 patients with adult-onset acid maltase deficiency.
abstract: BACKGROUND
  In acid maltase deficiency (AMD), electrical myotonia (EM) may be restricted to paraspinal muscles. A comprehensive description of the electromyographic (EMG) findings in AMD is lacking. The purpose of this study is to describe the EMG features in adult-onset AMD, focusing on the distribution of EM.
  
  
  METHODS
  A retrospective chart review of AMD patients diagnosed at Mayo Clinic over age 18 years.
  
  
  RESULTS
  Thirty-seven patients were included. Twenty-eight (76%) had EM in at least 1 muscle, and EM was more common in paraspinal and proximal limb muscles. The tensor fasciae latae (TFL) was equally sensitive to the paraspinals for EM. Three of 4 patients had EM identified in the diaphragm.
  
  
  CONCLUSIONS
  Approximately three-quarters of adult-onset AMD patients display EM on EMG. The paraspinal muscles and TFL are the most likely to demonstrate EM, and EM can be detected in the diaphragm of adult onset AMD patients.
authors.affiliation: Department of Neurology, Mayo Clinic, 200 1st Street SW, Rochester, MN, USA, 55905.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Kassardjian
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Engel
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Sorenson
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D003964:Diaphragm / Q000503:physiopathology; D004576:Electromyography; D005260:Female; D006009:Glycogen Storage Disease Type II / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D009222:Myotonia / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D064170:Paraspinal Muscles / Q000503:physiopathology; D012189:Retrospective Studies; D055815:Young Adult
keywords: EMG; Pompe disease; acid maltase deficiency; myotonia; myotonic discharge