title: The significance of pathological spontaneous activity in various myopathies.
abstract: OBJECTIVE
  Pathological spontaneous activity (PSA) in electromyography (EMG) has not yet been systematically analysed in various types of myopathies.
  
  
  METHODS
  136 Patients with well-defined myopathies were retrospectively analysed for the presence of PSA in distal, proximal, and paravertebral muscles. PSA comprised fibrillations (fib)/positive sharp waves (PSW) and high frequency discharges (HFD; i.e., myotonic and complex repetitive discharges).
  
  
  RESULTS
  fib/PSW occurred more frequently than HFD. HFD were rarely myotonic in nature. 50% and more patients presented with HFD in PROMM (80%), Pompe's disease (70%), matrin-3 myopathy (60%), sIBM (50%), CNM (50%), while far less than 50% of the patients showed RD in LGMD2I (21%), LGMD2A (17%), LGMD2B (17%), LGMD2L (14%), FSHD (4%), BMD (0%). Four different HFD patterns were proposed.
  
  
  CONCLUSIONS
  The segregation of myopathies relative to the occurrence of PSA and especially HFD in a high prevalence group and in a low prevalence group may be diagnostically valuable.
  
  
  CONCLUSIONS
  The screening for HFD by means of EMG is also valuable in the diagnosis of non-myotonic myopathies.
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, D-06120 Halle (Saale), Germany. Electronic address: frank.hanisch@medizin.uni-halle.de.
authors.forename: F
authors.initials: F
authors.lastname: Hanisch
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, D-06120 Halle (Saale), Germany.
authors.forename: C
authors.initials: C
authors.lastname: Kronenberger
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, D-06120 Halle (Saale), Germany.
authors.forename: S
authors.initials: S
authors.lastname: Zierz
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, D-06120 Halle (Saale), Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kornhuber
mesh_terms: D000328:Adult; D004576:Electromyography; D005260:Female; D006009:Glycogen Storage Disease Type II / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000175:diagnosis* / Q000503:physiopathology; D049288:Muscular Dystrophies, Limb-Girdle / Q000175:diagnosis / Q000503:physiopathology; D012189:Retrospective Studies
keywords: Complex repetitive discharges; Electromyography; Limb girdle muscular dystrophy; Matrin 3 myopathy; Myotonic discharges