[Dyslexia: clinical, neurophysiological and neuropsychological manifestations during the treatment with nootropil].

Forty children with dyslexia, aged 7-12 years, have been randomized into two groups in an open controlled study: 18 of them received Nootropil (piracetam) in the dose of 100 mg/kg daily for 2 months and 22 were examined as a control group. Nootropil exerted positive effects on reading and spelling skills in 56% of children with dyslexia who demonstrated the improvement of fluency and accuracy of reading along with a significant decrease of specific errors (dysphonemic and visuospatial) in dictation. In the control group, the improvement was seen only in 10% of children. These data corresponded to the results of neuropsychological testing that demonstrated the improvement of automatic lexical retrieval, phonological skills and sustained attention in dyslexic children treated with nootropil as compared to the control group. The dynamics of interhemispheric asymmetry in EEG alpha-theta-subbands (4-13 Hz) during the performance of incomplete figures recognition test in the nootropil treatment may be indicative of the formation of compensative mechanisms linked with the functional activation of the right hemisphere structures and associative anterior left hemisphere areas which contributed to the progress in reading and spelling skills.

[Visual evoked potentials to the sinusoidal grid in studying amblyopia in children]. / Zritel'nye vyzvannye potentsialy na sinusoidal'nye reshetki pri issledovanii ambliopii u detei.

Changes in the amplitude and time parameters of the visual evoked potentials (VEP) of the cortical visual projection area to sinusoidal reticula have been detected in 5-7-year-old children with amblyopia of varying severity; these changes have been particularly manifest in the high-frequency range. A relationship between the group VEP parameters and the vision status indicates the informative value of VEP as an indicator of visual cortex function.

[Effect of parameters of spatio-structural stimuli on evoked potentials of the visual and posterior associative regions of the cortex in man]. / Vliianie parametrov prostranstvenno-strukturirovannogo stimula na vyzvannye potentsialy zritel'noi i zadneassotsiativnoi oblastei kory u cheloveka.

In subjects with normal vision, differences have been detected in the reactions of the main components (P100, N150, P200) of evoked potentials recorded in the Oz and TPO leads, to homogeneous stimuli, chess fields with different sizes of cells and grids differing in area and the number of orientation stripes. The data obtained are discussed in the light of V.D. Glezer's hypothesis on specialized information processing in the visual and posterior associative cortical areas and concepts on the existence of separate channels of processing different image properties.

[Human visual evoked potentials to spatially structured stimuli in normal subjects and early object vision deprivation]. / Zri tel'nye vyzvannye potentsialy cheloveka na prostranstvenno-struktirovannye stimuly v norme i pri rannei deprivatsii predmetnogo zreniia.

For the analysis of plastic rearrangements in the visual system under the influence of different conditions of adaptation and early deprivation of objective vision, VEPs to checkerboard patterns with various check sizes were studied in subjects with normal vision and with amblyopia resulting from a congenital cataract. Sensitivity of P 180-230 component to the check sizes was revealed as well as a shift of its optimum toward bigger sizes following a transition from the light to the dark adaptation. In amblyopic subjects, in response to the checkerboard patterns the amplitude of P 80-120 component significantly increased, whereas that of P 180-230 decreased, with a shift of its optimum toward bigger check sizes. Informational significance of VEP waves and possible mechanisms of amblyopia are discussed.

[Evoked potentials to perception of photic stimuli of different intensity in normal subjects and optic nerve atrophy]. / Vyzvannye potentsialy pri vospriiatii svetovykh stimulov raznoi intensivnosti v nrome i pri atrofii zritel'nogo nerva u cheloveka.

In 30 subjects with normal vision an increase in stimulus brightness (8 gradations) led to reduction in pick-latencies (PL) of II-VII waves and to an increase in their amplitudes (A), maximal in the IV positive wave with PL amounting to 102-109 msec. Atrophy of optical nerves produced an impairment of power processing of the signal and its temporal characteristics, a decline of A III, IV waves (especially pronounced in IV) and a tendency to an increase in A V and VI waves. Informational significance of PL waves and characteristics of information processing with impaired vision are discussed.