Improved Amplitude of Myogenic Motor Evoked Responses after Paired Transcranial Electrical Stimulation during Sufentanil/Nitrous Oxide Anesthesia

1995 ◽  
Vol 83 (2) ◽  
pp. 270-276. ◽  
Author(s):  
Cor J. Kalkman ◽  
Leon H. Ubags ◽  
Henk D. Been ◽  
Astrid Swaan ◽  
John C. Drummond
Keyword(s):  
Aortic Surgery ◽  
Maximum Amplitude ◽  
Single Pulse ◽  
Single Stimulus ◽  
Transcranial Electrical Stimulation ◽  
Anesthetic Techniques ◽  
Transcranial Stimulation ◽  
Evoked Responses ◽  
Paired Stimuli ◽  
Electrical Stimuli

Background Measurement of motor evoked responses to transcranial stimulation (tc-MER) is a technique for intraoperative monitoring of motor pathways in the brain and spinal cord. However, clinical application of tc-MER monitoring is hampered because most anesthetic techniques severely depress the amplitude of motor evoked responses. Because paired electrical stimuli increase tc-MER responses in awake subjects, we examined their effects in anesthetized patients undergoing surgery. METHODS. Eleven patients whose neurologic condition was normal and who were undergoing spinal or aortic surgery were anesthetized with sufentanil-N20-ketamine. Partial neuromuscular blockade (single-twitch height 25% of baseline) was maintained with vecuronium. Single and paired electrical stimuli were delivered to the scalp, and compound action potentials were recorded from the tibialis anterior muscle. The amplitude and latency of the tc-MERs were measured as the interval between paired stimuli was varied between 0 (single stimulus) and 10 ms. All recordings were completed before spinal manipulation or aortic clamping. Results Median amplitude of the tc-MER after a single stimulus was 106 microV (10th-90th percentiles: 23-1,042 microV), and the latency to onset was 33.2 +/- 1.4 ms (SD). With paired stimuli (interstimulus interval 2-3 ms), tc-MER amplitudes increased to 285 (79-1,605) microV, or 269% of the single-pulse response (P < 0.01). Reproducibility of individual responses increased with paired stimulation. Onset latency decreased to 31.4 +/- 3.2 ms (P < 0.05). Maximum amplitude augmentation was observed with interstimulus intervals between 2 and 5 ms and in patients with low-amplitude responses after single-pulse stimulation. Conclusions Application of paired transcranial electrical stimuli increases amplitudes and reproducibility of tc-MERs during anesthetic-induced depression of the motor system. The effect may represent temporal summation of stimulation at cortical or spinal sites. The results of this study warrant further clinical evaluation of paired transcranial stimulation.

A Double-blind Protocol Comparing Regional and General Anesthetic Techniques during Abdominal Aortic Surgery

1994 ◽  
Vol 81 (SUPPLEMENT) ◽  
pp. A65
Author(s):  
R. B. Gorman ◽  
EJ. Norris ◽  
MJ. Breslow ◽  
JA. Grass ◽  
C. Beattie
Keyword(s):  
Aortic Surgery ◽  
Anesthetic Techniques ◽  
General Anesthetic ◽  
Double Blind ◽  
Abdominal Aortic Surgery ◽  
Abdominal Aortic

Somatosensory gating is altered and associated with migraine chronification: A magnetoencephalographic study

Cephalalgia ◽  
2017 ◽  
Vol 38 (4) ◽  
pp. 744-753 ◽  
Author(s):  
Fu-Jung Hsiao ◽  
Shuu-Jiun Wang ◽  
Yung-Yang Lin ◽  
Jong-Ling Fuh ◽  
Yu-Chieh Ko ◽  
...  
Keyword(s):  
Chronic Migraine ◽  
Migraine Without Aura ◽  
Headache Frequency ◽  
Sensory Modulation ◽  
Brain Excitability ◽  
Paired Stimuli ◽  
Somatosensory Cortices ◽  
First Response ◽  
Electrical Stimuli ◽  
Somatosensory Gating

Background Brain excitability is changed in migraine but not fully characterized yet. This study explored if somatosensory gating is altered in migraine and linked to migraine chronification. Methods Paired electrical stimuli were delivered to the left index fingers of 21 patients with migraine without aura (MO), 22 patients with chronic migraine (CM), and 36 controls. The first and second responses to the paired stimuli were obtained from the contralateral primary (cSI), contralateral secondary (cSII) and ipsilateral secondary (iSII) somatosensory cortices to compute the gating ratios (second vs. first response strengths). Results The first and second cSI responses and gating ratios differed in all groups ( p < 0.05); the responses were typically smaller in the MO and CM groups. The cSI gating ratio increased as a continuum across controls (0.73 ± 0.04, p < 0.001), MO (0.83 ± 0.04) to CM (0.97 ± 0.06) and was higher in CM vs. controls ( p < 0.001). When MO and CM were combined, cSI gating ratio was associated with headache frequency (r = 0.418, p = 0.005). Paired responses and gating ratios of cSII and iSII did not differ among the groups. Conclusions Somatosensory gating is altered in migraine and associated with headache chronification. Further studies must clarify if this abnormal sensory modulation is a true gating deficit independent of low preexcitation level.

scholarly journals The Connectivity Index: An Effective Metric for Grading Epileptogenicity

2019 ◽  
Author(s):  
Qi Yan ◽  
Nicolas Gaspard ◽  
Hitten P Zaveri ◽  
Hal Blumenfeld ◽  
Lawrence J. Hirsch ◽  
...  
Keyword(s):  
Average Distance ◽  
Single Pulse ◽  
Brain Regions ◽  
Control Site ◽  
Connectivity Index ◽  
Evoked Responses ◽  
Seizure Onset ◽  
Seizure Onset Zone ◽  
Site Of Stimulation ◽  
Stimulation Of

AbstractObjectiveTo investigate the performance of a metric of functional connectivity to classify and grade the excitability of brain regions based on evoked potentials to single pulse electrical stimulation (SPES).MethodsPatients who received 1-Hz frequency stimulation between 2003 and 2014 at Yale at prospectively selected contacts were included. The stimulated contacts were classified as seizure onset zone (SOZ), highly irritative zone (IZp) or control. Response contacts were classified as seizure onset zone (SOZ), active interictal (IZp), quiet or other. The normalized number of responses was defined as the number of contacts with any evoked responses divided by the total number of recorded contacts, and the normalized distance is the ratio of the average distance between the site of stimulation and sites of evoked responses to the average distances between the site of stimulation and all other recording contacts. A new metric we labeled the connectivity index (CI) is defined as the product of the two values.Results57 stimulation-sessions in 22-patients were analyzed. The connectivity index (CI) of the SOZ was higher than control (median CI of 0.74 vs. 0.16, p = 0.0002). The evoked responses after stimulation of SOZ were seen at further distance compared to control (median normalized distance 0.96 vs. 0.62, p = 0.0005). It was 1.8 times more likely to record a response at SOZ than in non-epileptic contacts after stimulation of a control site. Habitual seizures were triggered in 27% of patients and 35 % of SOZ contacts (median stimulation intensity 4 mA) but in none of the control or IZp contacts. Non-SOZ contacts in multifocal or poor surgical outcome cases had a higher CI than non-SOZ contacts in those with localizable onsets (medians CI of 0.5 vs. 0.12, p = 0.04). There was a correlation between the stimulation current intensity and the normalized number of evoked responses (r = + 0.49, p 0.01) but not with distance (r = + 0.1, p 0.64)ConclusionsWe found enhanced connectivity when stimulating the SOZ compared to stimulating control contacts; responses were more distant as well. Habitual auras and seizures provoked by SPES were highly predictive of brain sites involved in seizure generation.

Facilitation in Sea Anemones

1952 ◽  
Vol 29 (2) ◽  
pp. 235-254
Author(s):  
D. M. ROSS
Keyword(s):  
Bile Salt ◽  
Standardized Tests ◽  
Single Stimulus ◽  
Living Animal ◽  
Sea Anemones ◽  
Nerve Net ◽  
Reported Effect ◽  
High Doses ◽  
Electrical Stimuli ◽  
Very High

1. The previously reported effect of anemone extracts, the occurrence of quick closing responses to single electrical stimuli in Metridium, has been re-investigated. In standardized tests it was found that whereas hundreds of stimuli are required for each response to a single stimulus in untreated animals, after anemone extract the incidence of such responses is one per nine stimuli. 2. The incidence of these responses falls off with decreasing doses of extract and the effect disappears when less than 1/500th of the material from a single large Metridium is administered. There is no evidence that extracts from ‘stimulated’ and ‘unstimulated’ (i.e. anaesthetized or quick-frozen) anemones differ in potency. Extracts from divided animals show greater activity in the ‘sphincter-disk’ fraction. 3. The incidence of the responses also falls off in time and is highest from 15 to 30 sec. after beginning the treatment. The effect is sporadic and short-lived and responses to two or more successive stimuli are exceptional. 4. A number of treatments, such as drastic changes in pH, KCl(K+ x 8), tetramethylammonium hydroxide (1 : 100), NH4C1 (1 : 340) and especially bile salt and saponin, have similar effects. Drugs with neuro-muscular effects elsewhere (acetylcholine, adrenaline, tyramine, histamine, etc.) were generally ineffective except at very high doses. Food stimulants too were ineffective. 5. From the time relations and other aspects of the responses to single stimuli it is concluded that the effect should not be attributed to a substance with the function of a ‘facilitator’ in the living animal. 6. While the effects are consistent with the passage of occasional adventitious impulses in the nerve net, there is a singular absence of spontaneous or post-stimulus contractions. Certain implications of this feature of the results are discussed.

Acetylcholine release by a stimulus train lowers atrial fibrillation threshold

1987 ◽  
Vol 253 (4) ◽  
pp. H863-H868 ◽  
Author(s):  
D. E. Euler ◽  
P. J. Scanlon
Keyword(s):  
Atrial Fibrillation ◽  
Action Potential ◽  
Right Atrium ◽  
Single Pulse ◽  
Monophasic Action Potential ◽  
Adrenergic Blockade ◽  
The Right ◽  
Alpha Chloralose ◽  
Electrical Stimuli ◽  
Local Release

This study was designed to evaluate the importance of local release of autonomic neuromediators when electrical stimuli are applied to the right atrium to measure the atrial fibrillation threshold (AFT). Experiments were performed in 16 open-chest dogs anesthetized with alpha-chloralose. The dogs were denervated by bilateral transection of the stellates and cervical vagi. The AFT was determined in 11 dogs by delivering either a train of stimuli (14 pulses, 4 ms, 100 Hz) or a single stimulus (10 ms) to the right atrium during its vulnerable period. In eight dogs, beta-adrenergic blockade with timolol (0.1 mg/kg) had no effect on the AFT determined with either method. Atropine (0.2 mg/kg), given after timolol, significantly increased the train-of-pulses AFT from 4.7 +/- 0.4 to 32.3 +/- 4.6 mA (P less than 0.001). The single-pulse AFT increased from 16.5 +/- 1.5 to 17.8 +/- 1.5 mA (P less than 0.05). Atropine had a similar effect on the AFT when it was given in the absence of timolol (n = 3). In five additional dogs, a monophasic action potential was recorded while a 10-mA train was delivered to the atrium during its absolute refractory period. There was marked shortening of the monophasic action potential duration (55 +/- 6 ms) in the first beat after the train. The shortening was totally abolished by atropine (0.2 mg/kg). The results suggest that a train of stimuli liberates local stores of acetylcholine, which cause a shortening of atrial repolarization time and a profound decrease in the current necessary to evoke fibrillation.

Single Pulse Electrical Stimulation to identify epileptogenic cortex: Clinical information obtained from early evoked responses

2016 ◽  
Vol 127 (2) ◽  
pp. 1088-1098 ◽  
Author(s):  
B.E. Mouthaan ◽  
M.A. van ‘t Klooster ◽  
D. Keizer ◽  
G.J. Hebbink ◽  
F.S.S. Leijten ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Clinical Information ◽  
Single Pulse ◽  
Evoked Responses

scholarly journals Fundamental Perceptual Characterization of an Integrated Tactile Display with Electrovibration and Electrical Stimuli

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 301 ◽  
Author(s):  
Seiya Komurasaki ◽  
Hiroyuki Kajimoto ◽  
Hiroki Ishizuka
Keyword(s):  
Single Stimulus ◽  
Tactile Display ◽  
Micro Fabrication ◽  
Tactile Displays ◽  
Tactile Stimuli ◽  
Friction Pressure ◽  
Electrical Stimuli ◽  
The Relationship

Tactile displays have been widely studied for many decades. Although multiple tactile stimuli are more effective to improve the quality of the presented tactile sensation, most tactile displays provide a single tactile stimulus. An integrated tactile display with electrovibration and electrical stimuli is proposed herein. It is expected that vibrational friction, pressure and vibration can be presented at the same time through the tactile display. Also, these stimuli only require electrodes for stimulation. Therefore, the tactile display can be easily miniaturized and densely arrayed on a substrate. In this study, a tactile display is designed and fabricated using the micro-fabrication process. Furthermore, the display is evaluated. First, the relationship between a single stimulus and the perception is investigated. The electrovibration and electrical stimuli have a frequency dependence on perception. Second, whether the multiple stimuli with the electrovibration and electrical stimuli are perceivable by the subjects is also evaluated. The results indicate that the multiple tactile stimuli are perceivable by the subjects. Also, the possibility that the electrovibration and electrical stimuli affect each other is confirmed.

The Societal Hazards of Neuroenhancement Technologies

2018 ◽  
pp. 163-196
Author(s):  
Nils-Frederic Wagner ◽  
Jeffrey Robinson ◽  
Christine Wiebking
Keyword(s):  
Electrical Stimulation ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Cognitive Enhancement ◽  
Emerging Technology ◽  
Transcranial Electrical Stimulation ◽  
Transcranial Stimulation ◽  
Cognitive Enhancers ◽  
Emergent Technologies ◽  
Pharmacological Cognitive Enhancement

Using cognitive enhancement technology is becoming increasingly popular. In another paper, the authors argued that using pharmacological cognitive enhancers is detrimental to society, through promoting competitiveness over cooperation, by usurping personal and social identifies and thus changing our narrative and moral character. In this chapter, the authors seek to expand that argument by looking at an emerging technology that is rapidly gaining popularity, that of transcranial stimulation (TS). Here the authors explore TS via two major methods, transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES). In this, the authors seek to demonstrate that artificial cognitive enhancement is detrimental to society. Furthermore, that the argument can be applied beyond the moral dubiousness of using pharmacological cognitive enhancement, but applied to new, emergent technologies as well. In other words, artificial cognitive enhancement regardless of the technology/medium is detrimental to society.

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