The effect of chronic nausea on gastric slow wave spatiotemporal dynamics in children

Abstract

Background: Chronic nausea in adolescents with functional gastrointestinal disorders is an increasingly reported but poorly understood symptom that negatively affects quality of life. Functional gastrointestinal disorders are known to correlate closely with slow wave rhythm disturbances. The ability to characterize gastric electrophysiologic perturbations in functional nausea patients could provide potential diagnostic and therapeutic tools for nausea patients.

Methods: We used high-resolution electrogastrograms (HR-EGG) to measure gastric slow wave parameters in pediatric chronic nausea patients and healthy subjects both pre- and postprandial. We computed the dominant frequency, percentage power distribution, gastric slow wave propagation direction, and speed from HR-EGG.

Key results: We observed significant differences in the dominant frequency and power distributed in normal and bradyarrhythmia frequency ranges when comparing patients and healthy subjects. Propagation patterns in healthy subjects were predominantly anterograde, while patients exhibited a variety of abnormalities including retrograde, anterograde, and disrupted patterns. There was a significant difference in the preprandial mean slow wave direction between healthy subjects (222° ± 22°) and patients (103° ± 66°; p ˂ 0.01), although the postprandial mean direction between healthy subjects and patients was similar (p = 0.73). No significant difference in slow wave propagation speed was found between patients and healthy subjects in either pre- (p = 0.21) or postprandial periods (p = 0.75).

Conclusions and inferences: The spatiotemporal characterization of gastric slow wave activity using HR-EGG distinguishes symptomatic chronic nausea patients from healthy subjects. This characterization may in turn inform and direct clinical decision-making and lead to further insight into its pathophysiology.

Keywords: chronic nausea; electrogastrogram; gastric slow wave; pediatrics.

FIGURE 1

Experimental setup to measure HR-EGG with cutaneous electrodes in human subject

FIGURE 2

Butterworth filtered 25 channel HR-EGG and power spectra from (A) healthy pediatric subject and (C) nausea patient. SOBI-reconstructed EGGs and corresponding power spectra in (B) healthy pediatric subject and (D) nausea patient

FIGURE 3

(A) Mean slow wave frequency and (B) percent power distributed (PPD) in brady-, normo-, and tachy gastric frequency ranges for HR-EGG in healthy pediatric subjects and nausea patients before and after a test meal. Statistically significant differences between healthy subjects and nausea patients were denoted using *

FIGURE 4

(A) HR-EGG propagation maps during the preprandial period in a healthy pediatric subject show normal anterograde propagation as the activity moves from right to left (corresponding to the subject’s left to right). HR-EGG nausea patients data show (B) anterograde, (C) retrograde, and (D) disrupted propagation patterns. Position of electrode array is shown in the last map of (A)

FIGURE 5

HR-EGG propagation maps from a healthy subject and a nausea patient using (A-B) 2–4 cpm gastric frequency range and (C-D) 1–9 cpm gastric frequency range. These maps show corresponding maps for Figure 4A (healthy subject showing anterograde) and 4C (nausea patient showing retrograde propagation). Position of electrode array is shown in the last map of (5A)

FIGURE 6

Representative HR-EGG polar histograms showing estimated slow wave directions during a 120 second recording time in the preprandial period for (A) one healthy subject showing anterograde and three different nausea patients showing (B) anterograde, (C) retrograde, and (D) disrupted propagation patterns

FIGURE 7

Polar histograms for the mean gastric slow wave propagation direction from all subjects (A) preprandial heathy subjects; (B) postprandial heathy subjects; (C) preprandial nausea patients; and (D) postprandial nausea patients