Table 2

Associations between muscle relative T2 signal and corresponding regional, clinical and electrophysiological measures

Parameter associated with relative T2 signalRegression coefficient (95% CI)P value
Age0.001 (−0.002 to 0.004)0.395
Gender0.014 (−0.076 to 0.104)0.749
Days from symptom onset0.00004 (−0.00004 to 0.00012)0.345 (0.227)
ALSFRS-R−0.009 (−0.017 to –0.001)0.023 (0.022)
MRC summary score−0.003 (−0.0068 to 0.0001)0.060 (0.078)
MRC score right biceps−0.017 (−0.064 to 0.030)0.469 (0.794)
MRC score left biceps−0.079 (−0.147 to –0.011)0.024 (0.037)
MRC score right TA−0.107 (−0.142 to –0.071)<0.001 (<0.001)
MRC score left TA−0.069 (−0.091 to –0.046)<0.001 (<0.001)
Dynamometry right TA−0.005 (-0.007 to –0.002)<0.001 (<0.001)
Dynamometry left TA−0.005 (−0.007 to –0.003)<0.001 (<0.001)
MUNIX biceps−0.001 (−0.0020 to –0.0002)0.015 (0.077)
CMAP biceps−0.027 (−0.049 to –0.005)0.019 (0.092)
MUSIX biceps−0.0007 (−0.0063 to 0.0048)0.783 (0.703)
MUNIX TA−0.0018 (−0.0029 to –0.0007)0.003 (0.001)
CMAP TA−0.055 (−0.082 to –0.028)<0.001 (<0.001)
MUSIX TA−0.0008 (−0.0032 to 0.0015)0.460 (0.509)
  • Parameter estimates refer to unadjusted coefficients derived from regression models, with 95% CI in parentheses. P values refer to regression models unadjusted and, in parentheses, adjusted for age and gender. Significant results after correction for multiple comparisons are highlighted in bold.

  • ALSFRS-R, amyotrophic lateral sclerosis functional rating scale-revised; CMAP, compound muscle action potential; MRC, Medical Research Council; MUNIX, motor unit number index; MUSIX, motor unit number size; TA, tibialis anterior.