title: Clinical and Electrophysiological Findings in Hereditary Inclusion Body Myopathy Compared With Sporadic Inclusion Body Myositis.
abstract: OBJECTIVE
  To compare the clinical and electrophysiological findings in hereditary inclusion body myopathy (hIBM) and sporadic inclusion body myositis (sIBM) patients.
  
  
  METHODS
  We retrospectively identified 8 genetically proven hIBM patients and 1 DNAJB6 myopathy with pathological features of hIBM, and compared their clinical, electromyographic, and serological data with a group of 51 pathologically proven sIBM patients.
  
  
  RESULTS
  hIBM patients had a younger mean age of onset (36 vs. 60 years, P = 0.0001). Diagnostic delay was shorter in sIBM (6 vs. 15 years, P = 0.0003). Wrist flexors (P = 0.02), digit flexors (P = 0.01), digit extensors (P = 0.02), and quadriceps (P = 0.008) muscles were more frequently affected in sIBM. Fibrillation potentials were more common in sIBM patients (P = 0.03). Electrical myotonia was found in 4 hIBM patients, not significantly different from sIBM patients (P = 0.45). Creatinine kinase was higher in sIBM patients (799 vs 232, P = 0.03).
  
  
  CONCLUSIONS
  sIBM and hIBM seem to have similar electromyographic changes. The combination of clinical, serological, and histopathological findings can guide genetic testing to the final diagnosis.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Kazamel
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Sorenson
authors.forename: Margherita
authors.initials: M
authors.lastname: Milone
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D057210:Delayed Diagnosis; D049310:Distal Myopathies / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D004568:Electrodiagnosis; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology*; D018979:Myositis, Inclusion Body / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D009222:Myotonia / Q000473:pathology / Q000503:physiopathology; D012189:Retrospective Studies; D063189:Symptom Assessment