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Background: One of the most disabling problems in Parkinson disease (PD) is gait impairment. Noninvasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS), have been introduced as a therapeutic alternative for coping with PD motor problems. However, the effects of tDCS on gait performance in PD have not yet been fully established. Therefore, the main objective of this study was to evaluate whether a single session of tDCS modifies gait kinematics in individuals with PD. Methods: Twenty-one individuals with PD were included in this randomized, double-blinded, sham-controlled design study. They were randomly allocated in one real (N = 8) or sham (N = 9) tDCS group. Real tDCS comprises a 2-mA anodic current applied over 15 minutes in the supplementary motor area and medial areas of the primary motor cortices through a bipolar electrode montage. Gait kinematics and the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) were assessed before and immediately after a single stimulation session. Pre- minus poststimulation (Δ) values were computed and compared through a Mann-Whitney test. Data are shown as the median (lower, upper quartile). Results: There was a significant group difference with a large effect size for Δ values of gait cadence (P = .014, d = 0.87), indicating its reduction after anodic stimulation in the real (−0.28 [−1.16, 0.01] steps/s) compared with sham tDCS group (0.17 [0.00, 0.40] steps/s). No other significant effect was found. Conclusion: The findings of this study suggest that anodic tDCS administered in a single session improves gait cadence in PD individuals.

In this study we investigate to what extent the effects of motor imagery on postural sway are constrained by movement features and the subject's imagery ability. Twenty-three subjects were asked to imagine three movements using the kinesthetic modality: rising on tiptoes, whole-body forward reaching, and whole-body lateral reaching. After each task, subjects reported the level of imagery vividness and were subsequently grouped into a HIGH group (scores ≥3, “moderately intense” imagery) or a LOW group (scores ≤2, “mildly intense” imagery). An eyes closed trial was used as a control task. Center of gravity (COG) coordinates were collected, along with surface EMG of the deltoid (medial and anterior portion) and lateral gastrocnemius muscles. COG variability was quantified as the amount of fluctuations in position and velocity in the forward-backward and lateral directions. Changes in COG variability during motor imagery were observed only for the HIGH group. COG variability in the forward-backward direction was increased during the rising on tiptoes imagery, compared with the control task (p = 0.01) and the lateral reaching imagery (p = 0.02). Conversely, COG variability in the lateral direction was higher in rising on tiptoes and lateral reaching imagery than during the control task (p < 0.01); in addition, COG variability was higher during the lateral reaching imagery than in the forward reaching imagery (p = 0.02). EMG analysis revealed no effects of group (p > 0.08) or task (p > 0.46) for any of the tested muscles. In summary, motor imagery influences body sway dynamics in a task-dependent manner, and relies on the subject' imagery ability.

Objective: To investigate whether a sensorimotor deficit of the upper limb following a brachial plexus injury (BPI) affects the upright balance.Design: Eleven patients with a unilateral BPI and 11 healthy subjects were recruited. The balance assessment included the Berg Balance Scale (BBS), the number of feet touches on the ground while performing a 60 s single-leg stance and posturographic assessment (eyes open and feet placed hip-width apart during a single 60 s trial). The body weight distribution (BWD) between the legs was estimated from the center of pressure (COP) lateral position. The COP variability was quantified in the anterior-posterior and lateral directions.Results: BPI patients presented lower BBS scores (p = 0.048) and a higher frequency of feet touches during the single-leg stance (p = 0.042) compared with those of the healthy subjects. An asymmetric BWD toward the side opposite the affected arm was shown by 73% of BPI patients. Finally, higher COP variability was observed in BPI patients compared with healthy subjects for anterior-posterior (p = 0.020), but not for lateral direction (p = 0.818).Conclusions: This study demonstrates that upper limb sensorimotor deficits following BPI affect body balance, serving as a warning for the clinical community about the need to prevent and treat the secondary outcomes of this condition.

Plasma membrane Ca 2þ -ATPase is involved in the fine-tuned regulation of intracellular Ca 2þ . In this study, the presence of Ca 2þ -ATPase in caveolae from kidney basolateral membranes was investigated. With the use of a discontinuous sucrose gradient, we show that Ca 2þ -ATPase is exclusively located and fully active in caveolin-containing microdomains. Treatment with methyl-b-cyclodextrin -a cholesterol chelatorleads to a spreading of both caveolin and completely inactive Ca 2þ -ATPase toward high-density fractions. These data support the view that Ca 2þ fluxes mediated by Ca 2þ -ATPase in kidney epithelial cells occur only in caveolae, being strictly dependent on the integrity of these microdomains.

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These results showed that the global postural sway and the postural adjustments at ankle during standing balance change depending on the type of visual feedback information.

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