A recent retrospective study (LN Zhang et al. J Pediatr 2019; 205: 133-44) reviewed the records of 103 consecutive children with orthostatic intolerance and gastrointestinal symptoms, all of whom had undergone antroduodenal manometry (ADM). The median age was 17 years with a 3:1 female predominance. The same group has published a smaller study in 2016 with 35 children (A Darbari et al JPGN 2016; 63: 329-35).
In their methods, the authors stated that neurogenic intestinal dysmotility was diagnosed if there was
- At baseline, the authors state that 12 (12%) had neurogenic intestinal dysmotility and 8 (8%) had significant antral hypomoility.
- When ADM was undertaken in conjunction with tilt testing, the authors identified neurogenic intestinal dysmotility in 51 (50%), rumination/regurgitation in 23 (22%), and visceral hyperalgesia in 11 (11%).
- Abnormalities in ADM did not have any correlation with abnormal gastric emptying studies (GES)s (which were performed in 83 of 103). For example, among those with abnormal ADM (n=83), 48 (73%) had normal GES. And, among those with normal GES (n=58), 48 (83%) had abnormal ADM.
- “Analysis of EGD biopsy samples revealed nonspecific esophagitis and/or gastritis in 16 of 103 patients (15%)”
While this research provides some insight into why children with orthostatic intolerance may have gastrointestinal symptoms, I remain skeptical of the usefulness of ADM as a routine study in clinical practice. The authors claim that ADM has ‘potential importance…in its utility in targeting future therapies.’
- More uniformity in interpretation of ADM studies. I do not have specialized neurogastroenterology training, but my understanding is that the difference between normal and abnormal is often blurry.
- More effective motility agents including prokinetics and agents to improve visceral hyperalgesia. How helpful is it to identify subtle manometric abnormalities without effective therapeutic agents?
- If GI problems are only demonstrated during tilt testing, how important is this? I suspect that many individuals would have abnormalities if ADM was done while they were on a roller coaster, but I doubt that this would help me determine treatment for GI symptoms induced by this type of stimulus.