The IBI, total duration of the procedure and pulse waveform strongly affected the magnitude or duration of the plasticity induced by QPS. In this cohort, 80% of subjects responded to excitatory QPS as expected.

Background. Problems with gait in Parkinson's disease (PD) are a challenge in neurorehabilitation, partly because the mechanisms causing the walking disability are unclear. Weakness and fatigue, which may significantly influence gait, are commonly reported by patients with PD. Hence, the aim of this study was to investigate the association between weakness and fatigue and walking ability in patients with PD. Methods. We recruited 25 patients with idiopathic PD and 25 age-matched healthy adults. The maximum voluntary contraction (MVC), twitch force, and voluntary activation levels were measured before and after a knee fatigue exercise. General fatigue, central fatigue, and peripheral fatigue were quantified by exercise-induced changes in MVC, twitch force, and activation level. In addition, subjective fatigue was measured using the Multidimensional Fatigue Inventory (MFI) and Fatigue Severity Scale (FSS). Results. The patients with PD had lower activation levels, more central fatigue, and more subjective fatigue than the healthy controls. There were no significant differences in twitch force or peripheral fatigue index between the two groups. The reduction in walking speed was related to the loss of peripheral strength and PD itself. Conclusion. Fatigue and weakness of central origin were related to PD, while peripheral strength was important for walking ability. The results suggest that rehabilitation programs for PD should focus on improving both central and peripheral components of force.

Observing mouth movements has strikingly effects on the perception of speech. Any mismatch between sound and mouth movements will result in listeners perceiving illusory consonants (McGurk effect), whereas matching mouth movements assist with the correct recognition of speech sounds. Recent neuroimaging studies have yielded evidence that the motor areas are involved in speech processing, yet their contributions to multisensory illusion remain unclear. Using functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) in an event-related design, we aimed to identify the functional roles of the motor network in the occurrence of multisensory illusion in female and male brains. fMRI showed bilateral activation of the inferior frontal gyrus (IFG) in audiovisually incongruent trials. Activity in the left IFG was negatively correlated with occurrence of the McGurk effect. The effective connectivity between the left IFG and the bilateral precentral gyri was stronger in incongruent than in congruent trials. The McGurk effect was reduced in incongruent trials by applying single-pulse TMS to motor cortex (M1) lip areas, indicating that TMS facilitates the left IFG-precentral motor network to reduce the McGurk effect. TMS of the M1 lip areas was effective in reducing the McGurk effect within the specific temporal range from 100 ms before to 200 ms after the auditory onset, and TMS of the M1 foot area did not influence the McGurk effect, suggesting topographical specificity. These results provide direct evidence that the motor network makes specific temporal and topographical contributions to the processing of multisensory integration of speech to avoid illusion.

Parkinson's disease (PD) patients experience various symptoms including extrapyramidal motor disturbances and cognitive impairments, which cause difficulties in daily life. However, PD patients have rarely been studied under realistic task situations that require high-level interaction of cognitive and motor skills. The aim of this study was to investigate the contribution of cognitive and motor factors to the performance of PD patients under high cognitive and kinematic loads. Twenty-six PD patients and 14 control subjects participated in the study. The PD patients performed a task involving hitting targets and avoiding distractors in levodopa On and Off states. A robotic manipulandum device recorded the numbers of target and distractor hits and hand kinematics, including movement area and speed. Performance on standard cognitive batteries and the Movement Disorder Society – Unified Parkinson's Disease Rating Scale motor scores were examined. The results indicated that the PD patients hit significantly fewer targets and more distractors than did the controls (p < 0.05). In PD patients, the average hand speed was slower and the area of hand movement was smaller than those of the control subjects (p < 0.001). Levodopa significantly increased the average hand speed and movement area (p < 0.01), but levodopa had an insignificant effect on the number of correct targets hit and erroneous distractor hits. The scores of cognitive batteries predicted the performance with regard to both targets hit and distractor avoidance. Our results were indicative of a dynamic interaction between cognitive and kinematic skills while the PD patients performed a virtual reality game. Single-dose levodopa enhanced kinematic capacity, and the global intelligence level predicted game performance.

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