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Abstract: Event-related beamformer analyses was applied to magnetoencephalographic data from five subjects who performed synchronized and syncopated unimanual motor coordination tasks at rates ranging from 1.25 to 1.75 Hz. For syncopation, the stability of the coordination pattern decreased systematically with increasing movement rate. Averaged sensor data revealed the motor field (MF) and motor evoked fields (MEF) I and II. Additionally, we observed an early field (M0) at approximately 160 ms prior to peak flexion with polarity opposite to the MF. Beamformer analysis reproduced previous findings that showed the MF activity being generated mainly in precentral gyrus and the activity of the MEFs is distributed across multiple generators in pre- and post-central gyrus. For syncopation, additional areas of activation were observed during early M0 and late MEF II time periods which included premotor, frontal, cingulate, and SMA, with the premotor areas exhibiting a dependence on rate. These results provide evidence of the power of MEG beamforming for characterizing the properties of cortical neural activity at a high resolution in space and time. [Copyright &y& Elsevier]

Abstract: We studied changes in neural synchronization during the learning and stabilization in a perceptual motor task involving polyrhythmic bimanual force production. Effects of inter-hemispheric synchronization, captured in terms of changes in time-resolved phase synchrony, were clearly related to the stability of motor performance and could be interpreted as a result of altered transcallosal crosstalk. [Copyright &y& Elsevier]

Abstract: Results of shunting or other treatment for gait apraxia associated with normal pressure hydrocephalus and periventricular ischemia are still dubious and the condition is progressive. We treated 15 consecutive cases by a two pronged approach using rapid magnetic stimulation (RMS) and sonolysis. Patients selected presented primarily with gait apraxia. All were evaluated by full clinical and blood examination, MRI, MRA and ultrasound of the neck and cerebral vessels. Rapid magnetic stimulation was administered daily for seven days and sonolysis or therapeutic ultrasound for three days. Patients were reviewed for three months and therapy repeated. The Barthel''s index was used for evaluation. The data before treatment was compared with that after six months and there was overall statistically significant improvement. Shunt therapy could be avoided and two post shunt failures responded to this regime. [Copyright &y& Elsevier]

Abstract: To study the possible functional role of event-related de-synchronization in the beta band we altered various motor parameters in order to challenge the level of synchronization. We recorded whole-head MEG, bilateral EMG, and force during a rhythmic motor task, in which participants had to produce isometric forces paced by acoustic stimuli. Movement rate, force level, and task difficulty (synchronization vs. syncopation) were manipulated and changes in synchronization were analyzed. The results indicated that beta amplitude was mainly affected by ‘low-order’ motor parameters, such as force level and movement rate. [Copyright &y& Elsevier]