Repetitive peripheral magnetic stimulation (rPMS) may improve motor function following central nervous system lesions, but the optimal parameters of rPMS to induce neural plasticity and mechanisms underlying its action remain unclear. We examined the effects of rPMS over wrist extensor muscles on neural plasticity and motor performance in 26 healthy volunteers. In separate experiments, the effects of rPMS on motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI), intracortical facilitation (ICF), direct motor response (M-wave), Hoffmann-reflex, and ballistic wrist extension movements were assessed before and after rPMS. First, to examine the effects of stimulus frequency, rPMS was applied at 50, 25, and 10 Hz by setting a fixed total number of stimuli. A significant increase in MEPs of wrist extensors was observed following 50 and 25 Hz rPMS, but not 10 Hz rPMS. Next, we examined the time required to induce plasticity by increasing the number of stimuli, and found that at least 15 min of 50 and 25 Hz rPMS was required. Based on these parameters, lasting effects were evaluated following 15 min of 50 or 25 Hz rPMS. A significant increase in MEP was observed up to 60 min following 50 and 25 Hz rPMS; similarly, an attenuation of SICI and enhancement of ICF were also observed. The maximal M-wave and Hoffmann-reflex did not change, suggesting that the increase in MEP was due to plastic changes at the motor cortex. This was accompanied by increasing force and electromyograms during wrist ballistic extension movements following 50 and 25 Hz rPMS. These findings suggest that 15 min of rPMS with 25 Hz or more induces an increase in cortical excitability of the relevant area rather than altering the excitability of spinal circuits, and has the potential to improve motor output.
Purpose: To investigate the efficacy and complications of continuous wear of etafilcon A for therapeutic use. Materials and Methods: The subjects were 228 eyes of 219 outpatients prescribed Contact Lens (CL) for one week of continuous therapeutic wear during 10 years. The reason for prescription of CLs, the primary disease, the duration of CL wear and the complications were assessed retrospectively. Results: The predominant reason for prescription of CLs was relief of pain or a foreign-body sensation (62.3%) and protection of the corneal epithelium (20.6%). The primary disease was post-penetrating keratoplasty (36.8%), followed by corneal epithelial erosion (14.5%), post-lamellar keratoplasty (14.0%) and bullous keratopathy (12.2%). The average duration of wearing single lens was 6.5 ± 3.2 days. The average duration of wearing CLs in total was 9.2 ± 10.7 months. The most frequent problem associated with continuous wear of CLs was their dropping out of CLs (12.3%). The complications associated with CLs included conjunctivitis with papillary hyperplasia, corneal erosion and superficial punctate keratitis, but corneal ulcer and corneal infiltrates were not found. Conclusion: Serious complications were not shown changing the lenses every week to keep to the prescribed time limit for continuous therapeutic wear, even if corneal epithelial barrier function is impaired.
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