Cortical evoked responses to median nerve stimulation were recorded from 21 subjects during sevoflurane anaesthesia at the level of burst suppression in EEG. The N20/P22 wave had the typical form of a negative wave postcentrally, and positive precentrally. The amplitude exceeded 4 microV in all patients, making it easily visible without averaging on the low-amplitude suppression. These results show that two kinds of somatosensory evoked potential can be studied without averaging during EEG suppression in deep anaesthesia. One is the localised N20/P22 wave, which is seen regularly during suppression after stimuli with intervals exceeding 1 s. The other is the burst, involving the whole cortex, which is not evoked by every stimulus. We suggest that somatosensory evoked potentials can be monitored during sevoflurane-induced EEG suppression, and often can be evaluated reliably from a couple of single sweeps with stimulation interval exceeding 1 s. The enhancement of early cortical components of SEP, their adaptation to repeated stimuli, and the disappearance of later polysynaptic components during EEG suppression, give new possibilities to study the generators of SEP and the different effects of anaesthetics.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0168-5597(98)00005-7 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Causal evidence for increased theta and gamma phase consistency in a parieto-frontal network during the maintenance of visual attention.
Neuropsychologia
January 2025
Queensland Brain Institute, The University of Queensland; School of Psychology, The University of Queensland; CIFAR, Canada.
Endogenous visuo-spatial attention is under the control of a fronto-parietal network of brain regions. One key node in this network, the intra-parietal sulcus (IPS), plays a crucial role in maintaining endogenous attention, but little is known about its ongoing physiology and network dynamics during different attentional states. Here, we investigated the reactivity of the left IPS in response to brain stimulation under different states of selective attention.
View Article and Find Full Text PDFSomatosensory-Evoked Potentials and Clinical Assessments of Sensory Function Over Time in Patients With Subacute Stroke.
Neural Plast
January 2025
Department of Rehabilitation Medicine, School of Medicine, Tokai University, Kanagawa, Japan.
To demonstrate the utility of somatosensory evoked potentials (SEPs) following median nerve stimulation for chronological assessment of sensory function in patients with subacute stroke during rehabilitation. Retrospective study. Forty-seven patients with hemiparesis due to stroke during the subacute phase.
View Article and Find Full Text PDFComparative analysis of intraoperative thermal and optical imaging for identification of the human primary sensory cortex.
J Biomed Opt
January 2025
TU Dresden, Carl Gustav Carus Faculty of Medicine, Anesthesiology and Intensive Care Medicine, Clinical Sensing and Monitoring, Dresden, Germany.
Significance: The precise identification and preservation of functional brain areas during neurosurgery are crucial for optimizing surgical outcomes and minimizing postoperative deficits. Intraoperative imaging plays a vital role in this context, offering insights that guide surgeons in protecting critical cortical regions.
Aim: We aim to evaluate and compare the efficacy of intraoperative thermal imaging (ITI) and intraoperative optical imaging (IOI) in detecting the primary somatosensory cortex, providing a detailed assessment of their potential integration into surgical practice.
S8 Navigation system combined with an ultrasonic osteotome for three-dimensional real-time dynamic visualization decompression to reduce postoperative neurological deterioration in thoracic ossification of the ligamentum flavum.
Eur Spine J
January 2025
Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, 710054, China.
Background: Posterior laminectomy is a standard treatment for thoracic ossification of the ligamentum flavum (TOLF), but it often leads to neurological deterioration during surgery. This study aimed to reduce iatrogenic neurological deterioration by using an S8 navigation system combined with an ultrasonic osteotome for three-dimensional real-time dynamic visualization decompression.
Methods: A retrospective analysis was conducted on patients who underwent laminectomy and internal fixation for TOLF in our centre from January 2016 to January 2023.
Tactile edges and motion via patterned microstimulation of the human somatosensory cortex.
Science
January 2025
Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA.
Intracortical microstimulation (ICMS) of somatosensory cortex evokes tactile sensations whose properties can be systematically manipulated by varying stimulation parameters. However, ICMS currently provides an imperfect sense of touch, limiting manual dexterity and tactile experience. Leveraging our understanding of how tactile features are encoded in the primary somatosensory cortex (S1), we sought to inform individuals with paralysis about local geometry and apparent motion of objects on their skin.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!