Noninvasive Quantification of Nausea Severity in Pediatric Functional Nausea

Abstract

Background and aims: Functional nausea is an idiopathic gastrointestinal disorder that is common in children, carries a substantial health-care cost, and lacks objective diagnostic testing, relying primarily on symptomatology with an otherwise normal diagnostic workup. We hypothesize that high-resolution electrogastrogram (HR-EGG) spatiotemporal gastric slow wave parameters, reflective of known mechanisms of gastric uncoupling, are sensitive to nausea severity and can distinguish children with severe functional nausea when asymptomatic, from healthy pediatric controls.

Methods: We compared nonrandomized fasted HR-EGG recordings from control subjects (N = 10; 11-17 years; 3 M/7F) with recordings from functional nausea patients (N = 10; 12-18 years; 1M/9F) with inactive nausea at time of testing but had experienced nausea in the preceding 2 weeks. We used a second-order blind identification algorithm to minimize signal artifacts, identify gastric sources, and calculate spatiotemporal gastric slow wave frequency and propagation dynamics.

Results: Frequency dynamics showed significant differences between controls and patients in dominant frequency (2.7 ± 0.5 cycles per minute vs 2.2 ± 0.5 cycles per minute; P < .01), percentage of signal distribution in the normogastric range (59 ± 11.8% vs 46.5 ± 11%; P < .001), and bradygastric power percentage (20 ± 10.5% vs 28.1 ± 9.5%; P < .01). Propagation dynamics observed in patients were more complex and disordered, with significant differences in mean propagation direction (control: 223° ± 23°; patient: 20° ± 79°; P < .05), and propagation speed (P < .01).

Conclusion: We demonstrate that spatiotemporal analysis of HR-EGG propagation profiles differentiates pediatric functional nausea patients from controls. Given the high incidence of anxiety in children with functional nausea, future investigations should explore the influence of state and trait anxiety on HR-EGG parameters via the gut-brain axis.

Keywords: Functional Nausea; Gastric Slow Wave; Gastrointestinal Motility; High-Resolution Electrogastrogram; Pediatric.

Figure 1

Patient-reported BARF pictorial scale modified from 0 = absent, 10 = vomiting to 0 = absent, 8 = severe nausea, as vomiting is listed as exclusion criteria for Pediatric Functional Nausea and this study.

Figure 2

Experimental setup to measure patient and control HR-EGG using cutaneous electrodes.

Figure 3

(A) Gastric slow wave DFs from preprandial HR-EGG between controls and non-nauseated pediatric chronic nausea patients. (B) PPD showed significantly lower normal slow waves (P < .001) and significantly higher bradygastria (P < .01). (∗ indicates significant difference).

Figure 4

(A) Representative depiction of HR-EGG propagation map during the preprandial period in a healthy pediatric subject showing normal anterograde electrical activity moving from right to left and top to bottom (subject’s left to right) across the 25-channel cutaneous electrode array positioned on the skin surface. (B) Preprandial gastric propagation speed was determined from HR-EGG for pediatric control subjects (13.0 ± 3.4 mm/sec) and pediatric chronic nausea patients with inactive nausea (9.8 ± 3.5 mm/sec, P ˂ .01). (C-D) Polar histograms showing mean preprandial HR-EGG gastric slow wave propagation direction in pediatric controls (228° ± 49°) and non-nauseated chronic nausea patients (20° ± 79°, P ˂ .05).