Репозиторий Университета

© 2018 The Author(s). Background: To enrich the hitherto insufficient understanding regarding the mechanisms of action of transcranial direct current stimulation (tDCS) in pain disorders, we investigated its modulating effects on cerebral pain processing using functional magnetic resonance imaging (fMRI). Methods: Thirteen right-handed healthy participants received 20 min of 1.5 mA tDCS applied over the primary motor cortex thrice and under three different stimulation pattern (1.anodal-tDCS, 2.cathodal-tDCS, and 3.sham-tDCS) in a blinded cross-over design. After tDCS neural response to electric trigeminal-nociceptive stimulation was investigated using a block designed fMRI. Results: Pain stimulation showed a distinct activation pattern within well-established brain regions associated with pain processing. Following anodal tDCS increased activation was detected in the thalamus, basal ganglia, amygdala, cingulate, precentral, postcentral, and dorsolateral prefrontal cortex, while cathodal t-DCS showed decreased response in these areas (pFWE < 0.05). Interestingly the observed effect was reversed in both control conditions (visual- and motor-stimulation). Behavioral data remained unchanged irrespective of the tDCS stimulation mode. Conclusions: This study demonstrates polarity-specific modulation of cerebral pain processing, in reconfirmation of previous electrophysiological data. Anodal tDCS leads to an activation of the central pain-network while cathodal tDCS does not. Results contribute to a network-based understanding of tDCS's impact on cerebral pain-processing.

© 2018 Media Sfera. All Rights Reserved. Purpose: to assess the neurophysiological effect and clinical effectiveness of transcranial direct current stimulation in combination with drug therapy in amblyopic children. Material and methods. The study involved 32 healthy children in the age of 5-12 years and 97 patients of the same age with refractive strabismic amblyopia. All study subjects underwent standard examination including ophthalmological (visometry, refractometry in normal conditions and in cycloplegia, biomicroscopy, ophthalmoscopy, type of vision), neurophysiological methods (determination of retinal electric sensitivity threshold, electric lability of optic nerve, amplitude and latency period of visual evoked potentials, electroencephalogram wave amplitudes, localization of peak electrical activity area of the cerebral cortex), assessment of neuropsychic development and estimation of mental development coefficient with age tests. Results. Dynamics of neurophysiological parameters shows that healthy children develop fully functional retina, visual cortex and cortical-subcortical connections by 12 years. Children with refractive strabismic amblyopia in all age groups show statistically significant (p<0.05) deterioration of neurophysiological parameters of the visual analyzer, retardation of corticalsubcortical connections formation and lower electrical activity of the cerebral cortex. Amblyopic children show lower coefficients of mental development accompanied by intellectual deficiency and deterioration of learning ability. Proposed treatment method improved neurophysiological parameters of the visual analyzer in 83.5% of cases and increased visual acuity in 81.4% of cases. Improvement of psychological development resulted in better logical thinking, memory reinforcement and better adaptation to school educational environment in 86.6% of children.