scholarly journals Rapid high-amplitude circumferential slow wave propagation during normal gastric pacemaking and dysrhythmias

2012 ◽  
Vol 24 (7) ◽  
pp. e299-e312 ◽  
Author(s):  
G. O’Grady ◽  
P. Du ◽  
N. Paskaranandavadivel ◽  
T. R. Angeli ◽  
W. J. E. P. Lammers ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Slow Wave ◽  
High Amplitude

Origin and propagation of the slow wave in the canine stomach: the outlines of a gastric conduction system

2009 ◽  
Vol 296 (6) ◽  
pp. G1200-G1210 ◽  
Author(s):  
Wim J. E. P. Lammers ◽  
Luc Ver Donck ◽  
Betty Stephen ◽  
Dirk Smets ◽  
Jan A. J. Schuurkes
Keyword(s):  
Wave Propagation ◽  
Slow Wave ◽  
Ventral Surface ◽  
High Amplitude ◽  
Conduction System ◽  
Slow Waves ◽  
Low Velocity ◽  
Anesthetized Dogs ◽  
Greater Curvature ◽  
Low Amplitude

Slow waves are known to originate orally in the stomach and to propagate toward the antrum, but the exact location of the pacemaker and the precise pattern of propagation have not yet been studied. Using assemblies of 240 extracellular electrodes, simultaneous recordings of electrical activity were made on the fundus, corpus, and antrum in open abdominal anesthetized dogs. The signals were analyzed off-line, pathways of slow wave propagation were reconstructed, and slow wave velocities and amplitudes were measured. The gastric pacemaker is located in the upper part of the fundus, along the greater curvature. Extracellularly recorded slow waves in the pacemaker area exhibited large amplitudes (1.8 ± 1.0 mV) and rapid velocities (1.5 ± 0.9 cm/s), whereas propagation in the remainder of the fundus and in the corpus was slow (0.5 ± 0.2 cm/s) with low-amplitude waveforms (0.8 ± 0.5 mV). In the antrum, slow wave propagation was fast (1.5 ± 0.6 cm/s) with large amplitude deflections (2.0 ± 1.3 mV). Two areas were identified where slow waves did not propagate, the first in the oral medial fundus and the second distal in the antrum. Finally, recordings from the entire ventral surface revealed the presence of three to five simultaneously propagating slow waves. High resolution mapping of the origin and propagation of the slow wave in the canine stomach revealed areas of high amplitude and rapid velocity, areas with fractionated low amplitude and low velocity, and areas with no propagation; all these components together constitute the elements of a gastric conduction system.

scholarly journals Abnormal gastric slow waves in patients with functional dyspepsia assessed by multichannel electrogastrography

2001 ◽  
Vol 280 (6) ◽  
pp. G1370-G1375 ◽  
Author(s):  
Xuemei Lin ◽  
Jiande Z. Chen
Keyword(s):  
Wave Propagation ◽  
Functional Dyspepsia ◽  
Slow Wave ◽  
Single Channel ◽  
Slow Waves ◽  
Lower Percentage ◽  
Healthy Controls ◽  
Fasting State ◽  
Gastric Slow Wave ◽  
Gastric Slow Waves

The aim of this study was to utilize multichannel electrogastrography to investigate whether patients with functional dyspepsia had impaired propagation or coordination of gastric slow waves in the fasting state compared with healthy controls. The study was performed in 10 patients with functional dyspepsia and 11 healthy subjects. Gastric myoelectrical activity was measured by using surface electrogastrography with a specially designed four-channel device. The study was performed for 30 min or more in the fasting state. Special computer programs were developed for the computation of the propagation and coupling of the gastric slow wave. It was found that, compared with the healthy controls, the patients showed a significantly lower percentage of slow wave propagation (58.0 ± 8.9 vs. 89.9 ± 2.6%, P < 0.002) and a significantly lower percentage of slow wave coupling (46.9 ± 4.4 vs. 61.5 ± 6.9%, P < 0.04). In addition, the patients showed inconsistencies in the frequency and regularity of the gastric slow wave among the four-channel electrogastrograms (EGGs). It was concluded that patients with functional dyspepsia have impaired slow wave propagation and coupling. Multichannel EGG has more information than single-channel EGG for the detection of gastric myoelectrical abnormalities.

COMPARATIVE ANALYSIS OF NEUROPHYSIOLOGICAL FEATURES IN YOUNG WOMEN AND MEN SUFFERING FROM EPILEPSY

2021 ◽  
pp. 63-66
Author(s):  
A. О. Voitiuk ◽  
T. А. Litovchenko
Keyword(s):  
Comparative Analysis ◽  
Slow Wave ◽  
Low Frequency ◽  
Neurological Status ◽  
High Amplitude ◽  
Bioelectrical Activity ◽  
Key Words Epilepsy ◽  
Θ Rhythm ◽  
Definition Of ◽  
Gender Specific

The definition of epilepsy via the concept of neuronal discharge indicates the crucial importance of electroencephalography (EEG) in epileptology. This pathology is a certain problem for each sex, that requires gender−specific approaches when managing and treating such patients. To investigate them, 30 men and 30 women aged 18−44 years with a reliable diagnosis of epilepsy were examined. A comprehensive clinical, neurological and neurophysiological study of patients was performed, taking into account the data of clinical case and life history. Each patient was assessed for neurological status according to traditional methods, electrophysiological method of examination (routine EEG) was used. On the results of electroencephalography in individuals of both sexes with epilepsy, there was a decrease in the amplitude of the α−rhythm, but a significant slowdown in this rhythm was not detected. Most patients had high−amplitude (> 20 μV) and low−frequency β1−rhythm. Low−frequency high−amplitude slow−wave activity was regarded as an EEG reflection of degenerative−dystrophic processes in brain. Photostimulation caused paroxysms of bilaterally synchronous sharp and slow waves, complexes of "acute−slow" wave. Hyperventilation led to an increase in the θ−rhythm amplitude, appearance of δ−waves, higher expression of true epileptiform phenomena: adhesions, "acute wave−slow wave" complexes, "spike−slow wave" complexes. A comparative analysis of the obtained results allowed to conclude that the changes in bioelectrical activity in epilepsy occur according to the general mechanisms of epileptogenesis, regardless of gender. Key words: epilepsy, electroencephalogram, comparative analysis, young men and women.

Are Epileptic Spasms a Seizure Type for the Insular Region?

2020 ◽  
Vol 51 (04) ◽  
pp. 295-297 ◽  
Author(s):  
Volodymyr Kharytonov ◽  
Olivier Dulac
Keyword(s):  
Slow Wave ◽  
Late Onset ◽  
Motor Program ◽  
High Amplitude ◽  
The Other ◽  
Seizure Type ◽  
Wave Characteristic ◽  
The Third ◽  
Epileptic Spasms ◽  
Insular Region

AbstractTwo patients with insular and striatal postnatal scar had epileptic spasms (ES) that were asymmetrical and the only seizure type, whereas none of the usual ictal symptoms of insular seizures occurred. Ictal electroencephalography (EEG) showed the high-amplitude slow-wave characteristic of ES. Vigabatrin remained efficient for over 4 years for one patient and right into the third decade for the other one. Such ES are distinct from infantile and late onset spasms. Furthermore, these observations suggest that in ES insular epilepsy triggers paroxysmal activation of the striatum, and that vigabatrin inhibits the striatal startle motor program, thus interrupting the corticostriatal loop.

Slow waves actively propagate at submucosal surface of circular layer in canine colon

1990 ◽  
Vol 259 (2) ◽  
pp. G258-G263 ◽  
Author(s):  
K. M. Sanders ◽  
R. Stevens ◽  
E. Burke ◽  
S. W. Ward
Keyword(s):  
Wave Propagation ◽  
Slow Wave ◽  
Proximal Colon ◽  
Slow Waves ◽  
Pacemaker Cells ◽  
Transverse Axis ◽  
Active Mechanism ◽  
Conduction Velocities ◽  
Circular Layer ◽  
Thin Band

Colonic slow waves originate from pacemaker cells along the submucosal surface of the circular layer in the dog proximal colon. These events propagate in a nonregenerative manner into the bulk of the circular layer. Conduction velocities consistent with an active mechanism for slow-wave propagation in the longitudinal and circumferential axes of the colon have been reported. Experiments were performed using intracellular recording techniques on canine colonic muscles to determine the regenerative pathway for slow-wave propagation. In a thin band of muscle adjacent to the submucosal border of the circular layer, slow-wave amplitude was independent of distance from a pacing source, and events propagated at a rate of approximately 17 mm/s in the long axis of the circular fibers and 6 mm/s in the transverse axis of the circular fibers. These findings suggest that slow waves propagate in a regenerative manner in this region. Slow waves decayed as they conducted through regions from which the pacemaker cells had been removed with space constants of a few millimeters. Thus the integrity of the thin pacemaker region along submucosal surface is critical for propagation of slow waves and the organization of motility into segmental contractions.

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