Autonomic abnormalities in cyclic vomiting syndrome.
Level 4 - case-series / case-control
Case series of 6 patients without a control group
PubMed 17325552 · doi:10.1097/MPG.0b013e31802bddb7
What was done
Autonomic function testing was performed in 6 children diagnosed with cyclic vomiting syndrome (CVS) who were well hydrated and between vomiting episodes. Patients underwent three standard cardiovascular autonomic tests (heart rate variability with deep breathing, Valsalva maneuver, and tilt-table testing) and one sudomotor test.
What was found
All 6 patients had normal cardiovascular responses to deep breathing and the Valsalva maneuver. On tilt-table testing, all 6 showed a heart rate increase greater than 30 beats per minute, and 2 exhibited a vasodepressor response. Abdominal pain was triggered during tilt testing in 3 patients (at the blood pressure nadir in the 2 with vasodepressor changes, and in 1 additional patient with a history of syncope). Sudomotor testing was abnormal in all 6 patients (reduced response in 5 of 6, exaggerated response in 1 of 6). All 6 patients reported a personal or family history of migraine headaches.
Why it matters
The findings link pediatric cyclic vomiting syndrome to sympathetic vasomotor and sudomotor dysfunction, suggesting that CVS may share underlying autonomic neuropathy features with orthostatic intolerance and migraine.
Limits
The study is a very small case series of only 6 children with no control group. Testing was performed exclusively during interictal intervals when patients were asymptomatic, leaving autonomic physiology during acute emetic episodes unmeasured.
Cited by
- supports The autonomic nervous system is dysregulated in patients suffering from gastrointestinal disorders such as chronic vomiting syndromes.