Table 2.
Overview of the tested models for the effect of stimulation
| Association of stimulation on a decrease in CoP comp-score | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Controls (N = 10) | Eyes open | Eyes closed | Tandem | ||||||
| β | 95% CI | p | β | 95% CI | p | β | 95% CI | p | |
| Intercept | 0.24 | (-0.00 – 0.49) | 0.05 | -0.24 | (-0.47 to -0.02) | 0.04 | 0.31 | (-0.83 – 0.70) | 0.12 |
| Pre-stim score | 1.17 | (0.93 – 1.40) | 0.00 | -0.01 | (− 0.33 – 0.32) | 0.96 | 0.80 | (0.57 – 1.03) | 0.00 |
| Stimulation | 0.02 | (-0.09 – 0.12) | 0.73 | 0.08 | (− 0.01 – 0.16) | 0.07 | -0.08 | (-0.41 – 0.25) | 0.64 |
| Intercept | 0.24 | (-0.01 – 0.49) | 0.06 | -0.27 | (− 0.47 to -0.06) | 0.01 | 0.33 | (-0.27 – 0.93) | 0.28 |
| Pre-stim score | 1.17 | (0.93 – 1.40) | 0.00 | -0.05 | (− 0.47 – 0.30) | 0.76 | 0.79 | (0.53 – 1.05) | 0.00 |
| Stimulation | 0.02 | (-0.08 – 0.12) | 0.73 | 0.07 | (− 0.01 – 0.16) | 0.07 | -0.08 | (-0.41 – 0.25) | 0.64 |
| Order of measurements | 0.01 | (-0.08 – 0.10) | 0.81 | 0.03 | (− 0.06 – 0.11) | 0.57 | -0.04 | (-0.04 – 0.33) | 0.84 |
| Patients (N= 15) | |||||||||
| Intercept | 0.13 | (-0.05 – 0.30) | 0.15 | 0.02 | (− 0.09 – 0.12) | 0.75 | 0.16 | (-0.04 – 0.36) | 0.11 |
| Pre-stim score | 0.93 | (0.74 – 1.13) | 0.00 | 0.76 | (0.61 – 0.92) | 0.00 | 0.65 | (0.45 – 0.84) | 0.00 |
| Ipsi-lesional stimulation | -0.09 | (-0.18 to − 0.01) | 0.03 | -0.01 | (− 0.19 – 0.16) | 0.89 | -0.12 | (-0.30 – 0.06) | 0.18 |
| Contra-lesional stimulation | -0.07 | (-0.19 – 0.06) | 0.32 | 0.02 | (− 0.11 – 0.16) | 0.73 | -0.25 | (-0.48 to -0.03) | 0.03 |
| Intercept | 0.05 | (-0.11 – 0.21) | 0.54 | -0.04 | (− 0.20 – 0.12) | 0.64 | 0.25 | (0.07 – 0.43) | 0.01 |
| Pre-stim score | 0.94 | (0.79 – 1.09) | 0.00 | 0.75 | (0.60 – 0.91) | 0.00 | 0.64 | (0.46 – 0.82) | 0.00 |
| Ipsi-lesional stimulation | 0.00 | (-0.09 – 0.90) | 0.94 | 0.09 | (−0.08– 0.26) | 0.30 | -0.08 | (-0.55 – 0.40) | 0.75 |
| Contra-lesional stimulation | -0.02 | (-0.14 – 0.01) | 0.71 | 0.06 | (− 0.10 – 0.22) | 0.44 | -0.26 | (-0.43 to -0.09) | 0.00 |
| Sham at 3rd session | -0.01 | (-0.09 – 0.07) | 0.78 | -0.06 | (− 0.22 – 0.10) | 0.44 | -0.15 | (-0.64 – 0.34) | 0.54 |
| Sham at 2th session | 0.12 | (0.08 – 0.23) | 0.04 | 0.08 | (− 0.08 – 0.24) | 0.31 | -0.11 | (-0.29 – 0.06) | 0.20 |
| Post hoc analysis of the separate CoP parameters for the tandem position in patients | |||||||||
| ACoP | varCoP | Range* | |||||||
| β | 95% CI | p | β | 95% CI | p | β | 95% CI | p | |
| Intercept | 1.31 | (0.16 – 2.46) | 0.03 | 1.94 | (0.37 – 3.51) | 0.02 | 2.27 | (1.40 – 3.66) | 0.00 |
| Pre-stim score | 0.82 | (0.68 – 0.96) | 0.00 | 0.80 | (0.63 – 0.96) | 0.00 | 1.26 | (1.11 – 1.43) | 0.00 |
| Ipsi-lesional stimulation | -0.31 | (-1.37 – 0.75) | 0.57 | -0.30 | (− 1.74 – 1.13) | 0.68 | 0.98 | (0.89 – 1.06) | 0.57 |
| Contra-lesional stimulation | -0.86 | (-1.58 to -0.15) | 0.02 | -1.10 | (− 1.93 to -0.26) | 0.01 | 0.94 | (0.90 – 0.98) | 0.01 |
| Sham at 3rd session | -0.14 | (-1.20 – 0.92) | 0.80 | -0.35 | (− 1.79 – 1.10) | 0.64 | 0.97 | (0.89 – 1.05) | 0.44 |
| Sham at 2nd session | 0.01 | (-0.72 – 0.75) | 0.97 | -0.11 | (− 0.97 – 0.76) | 0.81 | 0.96 | (0.91 – 0.99) | 0.04 |
| VCoP* | varVCoP* | ||||||||
| Intercept | 1.38 | (1.12 – 1.72) | 0.00 | 1.63 | (1.26 – 2.10) | 0.00 | |||
| Pre-stim score | 1.40 | (1.30 – 1.50) | 0.00 | 1.32 | (1.21 – 1.44) | 0.00 | |||
| Ipsi-lesional stimulation | 0.98 | (0.87 – 1.1) | 0.68 | 0.98 | (0.85 – 1.12) | 0.73 | |||
| Contra-lesional stimulation | 0.97 | (0.94 – 0.99) | 0.02 | 0.97 | (0.93 – 1.01) | 0.11 | |||
| Sham at 3rd session | 1.00 | (0.89 – 1.12) | 0.96 | 0.98 | (0.86 – 1.12) | 0.78 | |||
| Sham at 2nd session | 0.98 | (0.95 – 1.00) | 0.07 | 0.96 | (0.92 – 1.01) | 0.08 | |||
Overview of the generalized estimating equation models that were tested for the effect of stimulation on post-measurement center of pressure (CoP) parameters in healthy controls and patients. All models were corrected for the individual pre-measurement CoP scores. If the β values in the model changed more than 10% by correcting for the randomized order of the stimulation to the model, this was considered an improvement of the model. Sham stimulation condition or sham stimulation condition at the first session was used as contrast. Parameters marked with an asterisk (*) were natural logarithmic transformed, the exponential functions of β and the CI are given in the table and should be interpreted as ratios
ACoP the mean amplitude of the CoP, variability of the mean amplitude of the CoP (varCoP), VCoP the velocity of the CoP, variability of the velocity of the CoP (varVCoP), β unstandardized beta value, CI confidence interval