Objective: Criteria for motor evoked potential (MEP) monitoring include the amplitude criterion and threshold criterion. The aim of our study for the amplitude criterion during removal of brain lesions was to determine a suitable stimulus intensity that can reduce the variability in amplitudes. We also assessed the usefulness of the threshold criterion and amplitude criterion by comparing the variability between the two methods as a preliminary study.
Methods: Seventeen patients including 12 cases with no neurological deterioration after surgery were enrolled in this study. The amplitudes in various stimulus intensities and the stimulation threshold (ST) were repeatedly measured during surgery. The stimulus intensities used in the amplitude criterion are described as 'the ST just after dura opening (ST(0))+additional intensity'. The variability was assessed with the coefficient of variation (CV).
Results: With direct cortical stimulation (DCS), the CVs of amplitudes were significantly lower at stimulus intensities of more than ST(0)+4 mA, with the smallest at ST(0)+10 mA. The CV of STs was significantly smaller than that of amplitudes.
Conclusions: The variability in the amplitude criterion was significantly reduced using stimulus intensities of more than ST(0)+4 mA. The variability in the threshold criterion was significantly smaller than that of the amplitude criterion, even when using a strong stimulus intensity.
Significance: The maximal stimulus intensity with no body motion should be used in the amplitude criterion for intraoperative MEP elicited by DCS.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.clinph.2014.10.005 | DOI Listing |
Sensors (Basel)
December 2024
Department of Engineering for Innovation, University of Salento, 73100 Lecce, Italy.
This study investigates the effectiveness of amplitude transformation in enhancing the performance and robustness of Multiscale Fuzzy Entropy for Alzheimer's disease detection using electroencephalography signals. Multiscale Fuzzy Entropy is a complexity measure particularly sensitive to intra- and inter-subject variations in signal amplitude, as well as the selection of key parameters such as embedding dimension () and similarity criterion (), which often result in inconsistent outcomes when applied to multivariate data, such as electroencephalography signals. To address these challenges and to generalize the possibility of adopting Multiscale Fuzzy Entropy as a diagnostic tool for Alzheimer's disease, this research explores amplitude transformation preprocessing on electroencephalography signals in Multiscale Fuzzy Entropy calculation across varying parameters.
View Article and Find Full Text PDFFoods
November 2024
School of Marine Science and Technology, Tokai University, 3-20-1 Orido, Shimizu-ku, Shizuoka-shi 424-8610, Shizuoka, Japan.
Fat content is the main criterion for evaluating albacore quality. However, no reports exist on the accuracy of the tail-cutting method, a method used to assess the fat content of albacore. Here, we evaluated this method by comparing it with chemical analysis and ultrasound inspection.
View Article and Find Full Text PDFSleep
December 2024
Centre for Biological Timing, Division of Neuroscience, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PT, UK.
Study Objectives: Melanopsin-expressing retinal ganglion cells, which provide light information to time sleep and entrain circadian clocks, also influence perceived brightness raising the possibility that psychophysical paradigms could be used to explore the origins and implications of variability in melanopic sensitivity. We aimed to develop accessible psychophysical tests of melanopic vision and relate outcomes with a pupillometric measure of melanopsin function (post-illumination pupil response; PIPR) and prior light exposure.
Methods: Individually calibrated pairs of isoluminant stimuli differing in melanopic radiance from a four primary source were presented sequentially with superimposed random colour offsets in a two alternative forced choice brightness preference paradigm to 41 naïve adult participants with personal light exposure data for the prior 7 days and PIPR measures defined by comparing maintained pupil constriction for luminance matched 'red' vs 'blue' pulses.
Chronobiol Int
December 2024
Department of Psychology, Swansea University, Swansea, UK.
Ophthalmic Physiol Opt
January 2025
The Ohio State University College of Optometry, Columbus, Ohio, USA.
Introduction: To determine whether classification of accommodative insufficiency (AI) based on the subjective push-up test is indicative of reduced amplitude measured objectively.
Methods: Monocular subjective accommodative amplitude was measured in participants 7-24 years of age with the push-up test; a 0.9 mm letter was moved towards the eye until first sustained blur occurred.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!