Search results for "Somatosensory evoked potential"

Neurophysiological studies of pain pathways in peripheral and central nervous system disorders.

2003

Standard clinical neurophysiological assessment of somatosensory pathways by sensory evoked potentials (SEPs) is limited to the tactile and proprioceptive systems consisting of large fibers in the peripheral nerve, the dorsal columns of the spinal cord and the medial lemniscus in the brainstem. This limitation means that about half of the lesions in the somatosensory system will not be detectable. In recent years, many clinical studies have confirmed that laser evoked potentials (LEPs) allow the assessment of the other half of the somatosensory system. Rapid heating of the skin by infrared laser pulses specifically activates the nociceptive and thermoreceptive pathways consisting of small f…

Evoked local field potentials can explain temporal variation in blood oxygenation level-dependent responses in rat somatosensory cortex

2010

The aim of this study was to explain the temporal variations between subjects in the blood oxygenation level-dependent (BOLD) response. Somatosensory responses were elicited with the electrical forepaw stimulus at a frequency of 10 Hz in urethane-anesthetized rats, and functional magnetic resonance imaging (fMRI) with BOLD contrast and local field potential (LFP) measurements were performed simultaneously. BOLD fMRI activation was evaluated by two different models, one based on the stimulus paradigm (the block model) and the other on the simultaneously measured evoked LFP responses. In the initial analysis, the LFP model captured the BOLD activation in the primary somatosensory cortex in al…

Somatosensory change detection in young healthy twin males

2013

2001

Little is known about somatosensory evoked potentials (SEPs) from muscle stimulation compared to that from skin stimulation. The current study examined this issue in the full SEP spectrum (0 - 440 ms). The aims of the study were to (1) establish the dynamics of early to late latency SEPs from intramuscular stimulation in contrast to surface stimulation, (2) compare the effect of non-painful and painful stimuli on SEP latencies and amplitudes of the two methods, and (3) investigate to which extent these results can be shared between the median nerve innervated thenar site and ulnar nerve innervated hypothenar site. Stimuli were delivered (2 Hz) at a non-painful and a painful intensity above …

Recommendations for the clinical use of somatosensory-evoked potentials

2008

The International Federation of Clinical Neurophysiology (IFCN) is in the process of updating its Recommendations for clinical practice published in 1999. These new recommendations dedicated to somatosensory-evoked potentials (SEPs) update the methodological aspects and general clinical applications of standard SEPs, and introduce new sections dedicated to the anatomical-functional organization of the somatosensory system and to special clinical applications, such as intraoperative monitoring, recordings in the intensive care unit, pain-related evoked potentials, and trigeminal and pudendal SEPs. Standard SEPs have gained an established role in the health system, and the special clinical ap…

“Small Volume Resuscitation” as Treatment of Cerebral Blood Flow Disturbances and Increased ICP in Trauma and Ischemia

1996

“Small volume resuscitation” (SVR) is a promising concept for the treatment of shock and trauma patients. SVR utilizes the fast infusion of a small volume of hypertonic saline to mobilize intraendothelial and parenchymal water to expand and restitute intravascular volume. Therefore it seems warranted to also consider SVR for the treatment of disturbances of the cerebral circulation and of increased intracranial pressure (ICP). The current study uses a rabbit model of global cerebral ischemia combined with mild hemorrhage to test SVR. Somatosensory evoked potentials (SEPs) serve as a short-term outcome parameter. The data demonstrate a beneficial effect on ICP, a better reperfusion, and an i…

MRI findings and evoked potentials in patients with myotonic dystrophy versus facioscapulohumeral dystrophy

1997

Evoked potentials recordings have been applied to many neurological disorders, localizing the lesions in the central nervous system (CNS) pathways. Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive degenerative disease involving the muscles of the face and shoulders. On the contrary, myotonic distrophy (MD), the most frequent and severe myotonic disease, is caracterized by myotonia (delay of relaxation after voluntary contraction), muscular atrophy and dystrophic changes in non-muscular tissues. In the present investigation, patients with clinically and electromyographically verified FSHD and MD were examined using somatosensory evoked potentials (SEP) and brainstem aud…