Health status in non-dystrophic myotonias: close relation with pain and fatigue

J Neurol. 2009 Jun;256(6):939-47. doi: 10.1007/s00415-009-5049-y. Epub 2009 Mar 1.


To determine self-reported health status in non-dystrophic myotonias (NDM) and its relationship to painful myotonia and fatigue. In a cross-sectional study, 32 NDM patients with chloride and 30 with sodium channelopathies, all off treatment, completed a standardised interview, the fatigue assessment scale (FAS), and the 36-item Short-Form Health Survey (SF-36). Beside formal assessment of pain, assessment of painful or painless myotonia was determined. The domain scores of the SF-36 were compared with Dutch community scores. Apart from the relationship among SF-36 scores and (1) painful myotonia and (2) fatigue, regression analyses in both NDM groups were conducted to determine the strongest determinants of the SF-36 domains general health perception, physical component (PCS) and mental component summary (MCS). All physically oriented SF-36 domains in both NDM groups (P <or= 0.01) and social functioning in the patients with sodium channelopathies (P = 0.048) were substantially lower relative to the Dutch community scores. The patients with painful myotonia (41.9%) scored substantially (P < 0.05) lower on most SF-36 domains than the patients without painful myotonia (58.1%). Fatigued patients (53.2%) scored substantially lower (P <or= 0.01) on all SF-36 domains than their non-fatigued counterparts (46.8%). The regression analysis showed that fatigue was the strongest predictor for the general-health perception and painful myotonia for the physical-component summary. None of the patients showed below-norm scores on the domain mental-component summary. The impact of NDM on the physical domains of patients' health status is substantial, and particularly painful myotonia and fatigue tend to impede their physical functioning.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Chloride Channels
  • Cross-Sectional Studies
  • Fatigue / complications*
  • Female
  • Health Status*
  • Humans
  • Interview, Psychological
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Myotonia / complications*
  • Myotonia / psychology*
  • Pain / complications*
  • Regression Analysis
  • Reproducibility of Results
  • Severity of Illness Index
  • Sodium Channels
  • Young Adult


  • Chloride Channels
  • Sodium Channels