title: Anterior tibialis CMAP amplitude correlations with impairment in CMT1A.
abstract: BACKGROUND
  CMT1A is the most common form of Charcot-Marie-Tooth disease (CMT), a slowly progressive neuropathy in which impairment is length dependent. Fibular nerve conduction studies to the anterior tibialis muscle (AT) may serve as a physiological marker of disease progression in patients with CMT1A. The objective of this study is to determine whether the AT compound muscle action potential (CMAP) amplitude correlates with impairment in patients with CMT1A.
  
  
  METHODS
  We correlated AT CMAP amplitudes and impairment measured by the CMT Neuropathy Score (CMTNS) in a cross-section of 121 patients with CMT1A and a subset of 27 patients with longitudinal data.
  
  
  RESULTS
  AT CMAP amplitudes correlated with impairment as measured by the CMTNS in cross sectional analysis. Longitudinal changes in the AT CMAP showed a strong inverse correlation with leg strength but not other components of the CMTNS.
  
  
  CONCLUSIONS
  AT CMAP amplitude may serve as a useful outcome measure for physiological changes in natural history studies and clinical trials for patients with CMT1A.
authors: Wayne State University-Detroit Medical Center, Department of Neurology, 4201 Saint Antoine Street, UHC 8C.28, Detroit, Michigan 48201, USA.
authors: Kelsey
authors: K
authors: Komyathy
authors: Stephanie
authors: S
authors: Neal
authors: Shawna
authors: S
authors: Feely
authors: Lindsey J
authors: LJ
authors: Miller
authors: Richard A
authors: RA
authors: Lewis
authors: George
authors: G
authors: Trigge
authors: Carly E
authors: CE
authors: Siskind
authors: Michael E
authors: ME
authors: Shy
authors: Sindhu
authors: S
authors: Ramchandren
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002607:Charcot-Marie-Tooth Disease / Q000503:physiopathology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003943:Diagnostic Techniques, Neurological; D018450:Disease Progression; D005260:Female; D006801:Humans; D007866:Leg / Q000294:innervation; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation*; D009431:Neural Conduction; D010543:Peroneal Nerve / Q000503:physiopathology*; D012189:Retrospective Studies