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Shigeru Koyano

Publications and source records attributed to Shigeru Koyano.

5 recordsLinked to original sources
PubMed2005

Visual event-related potentials under different interstimulus intervals in Parkinson's disease: relation to motor disability, WAIS-R, and regional cerebral blood flow.

We have introduced S1-S2 paradigm (task S) as well as oddball paradigm (task O) visual event-related potentials (ERPs) under different interstimulus intervals (ISIs) in Parkinson's disease (PD). ERP measurements were correlated with motor disability, WAIS-R, and regional cerebral blood flow (rCBF). The 'group' influence was characterized by longer latency for P300, N200, and reaction time and decreased P300 amplitude in PD. Both P300 latency and reaction time during task O showed significantly longer latency in longer ISI condition. Our results revealed 'ISI' influence on ERPs during task S and significant correlation between ERPs and rCBF in task S.

Aged↗
PubMed2005

[The therapeutic efficacy in Fisher syndrome].

We studied clinical courses of 15 cases of Fisher syndrome (FS) and examined therapeutic efficacy of plasma exchange (PE), immunoadsorption (IA), intravenous immune globulin (IVIg), and steroid therapy (ST). Compared with other treatments, PE and IA had shortened the peak period of the symptoms, but had not revealed the difference of the duration of illness between one another. As for PE and IA, the short-term effect was seen, but did not show the long-term effect. Though IVIg was done at the early stage, it did not shorten the peak period. So we conclude IVIg for FS to be effective not so equal as PE. However, clinical manifestations were milder in IVIg cases than PE, and there was a possibility that the symptoms of FS became mild by early treatment with Mg. Compared with Guillain-Barré syndrome, it is rare for FS to leave aftereffects and convalescence is good, so the choice of a therapy should be considered with a severity and complications.

Adult↗
PubMed2004

Visual evoked potential changes related to illusory perception in normal human subjects.

To study the human brain activity correlated with illusory perception, we chose a physically flat plane figure which looks like a convex figure. We studied visual evoked potential (VEP) changes, which reflect perceptual properties of illusory perception. We defined two paradigms, an illusory paradigm (IP) and a control paradigm (CP). Two stimuli, A and B, were randomly presented in the IP, while stimuli C and D were randomly presented in the CP. Stimulus A was the only figure which looked like a convex figure. A three-way analysis of variance was applied to the VEP components in each paradigm, with three factors: figures, electrodes, and sessions. Different configuration patterns between the two paradigms explained different grand mean VEP waveforms between the two paradigms; a greater N1 for the CP, a greater P1 for the IP, and marked attenuation of the N3 and P3 components for the IP. Significant main effects of figures only for the IP were found on P1 and P1N2 amplitude and P2 latency, which are assumed to reflect perceptual properties of stereoscopical illusory perception.

Adult↗
PubMed2003

The effect of stimulus-onset asynchrony on human visual event-related potentials during simple and choice reaction paradigms under constant or random conditions.

Visual event-related potentials (ERPs) were recorded during an oddball paradigm (OBP) and a simple reaction paradigm (SRP) to investigate the effect of stimulus-onset asynchrony (SOA) on ERPs under constant and random conditions in nine healthy individuals. NA was obtained by subtracting ERPs for SRP from those to the frequent nontarget of OBP. N2 was obtained by subtracting ERPs to the frequent nontarget from those to the rare target of OBP. N1, P2, and P3 latencies during OBP were shorter, and N1 amplitude of OBP, P1, and P2 amplitude of SRP, and NA amplitude were larger under constant conditions than under random conditions. We suggest that visual information processing is faster and more effective under constant conditions than under random conditions. NA potential related to the pattern recognition processing was significantly interfered with under random conditions, whereas N2 potential related to the stimulus classification was less influenced by the rhythm. The visual selective processing activity was influenced by the SOA with the positive shift of the waveform "20% rare target of OBP-100% target of SRP" under random conditions.

Adult↗