Kinematic measures.

<p>Means and standard deviations of reaction time (A), movement time (B), path length (C), peak velocity (D) and acceleration (E) are plotted for patients with PD (filled bars) and age-matched controls (empty bars). The stars and the empty circles represent the group mean of patients with clinically predominant right and left motor impairment, respectively. </p

Recorded data at gait initiation.

<p>Centre of pressure (CoP, black line) and centre of mass (CoM, dashed line) displacement in a healthy subject (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092736#pone-0092736-g001" target="_blank">figure 1</a> left) and child with RTT (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092736#pone-0092736-g002" target="_blank">figure 2</a> left) with corresponding EMG activity of tibialis anterior (TA) and soleus muscles (SOL) of swing and stance foot (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092736#pone-0092736-g001" target="_blank">figure 1</a> right and 2 right). The dotted line (in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092736#pone-0092736-g001" target="_blank">figure 1</a> left and 2 left) shows CoP-CoM distance at toe-off of the swing foot (SWto). In <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092736#pone-0092736-g001" target="_blank">figure 1</a> (right), arrows indicate bilateral suppression of the tonic activity of SOL which, together with the subsequent activation of TA, is responsible for the backward displacement of the CoP. This synergistic activity of pairs of postural muscles (i.e. TA and SOL) is not present in RTT girls (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0092736#pone-0092736-g002" target="_blank">figure 2</a> right). <i>Imbalance phase</i>, from the instant APAonset, at which the CoP start moving backward, to the instant of heel-off of the swing foot (SWho). <i>Unloading phase</i>, from SWho to toe-off of the swing foot (SWto). STto is the instant of toe-off of the stance foot.</p

Correlative analyses.

<p>A. Reaction times (x axis) are plotted against the values of beta power over the left ROI averaged over the 200 ms before target presentation (y axis). B. The amplitudes of Peak Velocities (x axis) are plotted against the degree of imaginary coherence between the two sensorimotor ROIs in the period just after target presentation where significant differences between the two groups were found (y axis). In both plots, filled circles represent patients with PD and empty circles the controls; the thick lines represent the fitting lines on the entire data set (patient and control groups combined), while the thin lines are for the PD group and the dotted lines for the controls. </p

EMG recordings (RMS).

<p>Imb. = Imbalance; Unl. = Unloading; SOL = Soleus muscle; TA = Tibialis anterior muscle; p values refers to Wilcoxon-Mann-Whitney U Test.</p

Beta power changes.

<p>A and B. Averages of the time courses of beta power changes in dB over the Left (solid line) and Right (dotted line) ROIs in controls (A) and patients with PD (B). The data were anchored at the time of target appearance (0 ms, filled arrows and thin solid lines). The empty arrows and thin dotted lines indicate the average time of movement onset (i.e., reaction time, RT) for each group. Negative time values on the X-axis represent the pre-target interval and from 0 to the empty arrow the reaction time period. Significant differences (p<0.05) between the two ROIs are indicated in the bottom part of each plot. C. Average of the normalized imaginary coherence in controls (thin line) and patients with PD (thick line). As in A and B, the data were anchored at the time of target appearance (0 ms, filled arrows). The empty arrows and vertical dotted lines indicate the average RT for each group. Significant differences between the two groups (p<0.05, nonparametric unpaired t-test with Bonferroni correction) are indicated in the bottom part of the plot. D. Individual differences of beta power between the left and the right ROIs averaged over the 200 ms time-interval before target appearance are plotted for the PD patients (on the left) and the controls (on the right). The thick horizontal lines represent the average for each group. The circles and the squares in the PD group represent patients with clinically predominant right and left motor impairment, respectively. </p

Kinematic measurements.

<p>AP = Antero-posterior; ML = Medio-materal. Imb. = Imbalance; Unl. = Unloading; FL = foot length; BH = body height; SWto = Heel-off of the swing foot. p values refers to Wilcoxon-Mann-Whitney U Test.</p

Demographic and clinical characteristics.

<p>Demographic and clinical characteristics.</p

Patients’ characteristics.

<p>* as determined by the UPDRS scores</p><p>Patients’ characteristics.</p

Modulation of the spectral power during the gait cycle.

<p>Event related synchronization (ERS) and desynchronization (ERD) in low <i>β-</i> (top) high <i>β-</i> (middle) and <i>γ</i>-frequency band (bottom). Subthalamic power changes of the phases of gait are shown as the average relative change of the whole stride of all subjects. Shaded areas represent the confidence intervals (5–95%) of the group mean. We analyzed the power changes of STN–and STN+ during the gait cycle of the contralateral foot (but they could be also referred to the matched gait phases of the ipsilateral one). Stance is the period during which the foot is on the ground (dark and light orange bars). The stance phase includes a period of bilateral foot contact with the floor (double-support phases [dark orange bars]), and a period of unilateral foot contact (single-support phase [light orange bar]). The swing phase (light green and dark green bars) is the interval in which the foot is lifted from the floor. Thanks to the velocity peak (VP) of the marker placed on the lateral malleolus, we identified an acceleration (light green) a deceleration (dark green) sub-phase of the swing phase. HS = heel strike; TO = toe off; VP = velocity peak; lower case subscript indicates the foot contralateral _(contra) or ipsilateral _(ipsi) to STN–or STN+.</p

Spectral profiles (single subject) during resting, upright standing and gait.

<p>Single subject spectral power of the STN local field potential during resting (blue line), standing (pink line) and gait for the two hemispheres, with less (–) and more (+) striatal dopamine innervation. Axial slices are left-right flipped to match the corresponding STN. The peak at 32 Hz is a known artefact of the Activa PC+S^® system tied to clock settings or due to a triggered check of the battery status. SPECT scans (central column) show striatal dopaminergic loss as percentage decline with respect to healthy subjects (calculated from BP_ND of DAT, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198691#pone.0198691.t003" target="_blank">Table 3</a>).</p