Autonomic nerve function in adults with cyclic vomiting syndrome: a prospective study.
Level 4 - case-series / case-control
Prospective case-control study
PubMed 20667005 · doi:10.1111/j.1365-2982.2010.01577.x
What was done
Prospective case-control study evaluating autonomic nerve function in 20 adult patients with cyclic vomiting syndrome (CVS, diagnosed by Rome III criteria; 14 women, 6 men) compared to 20 controls. Sympathetic function was tested via postural changes in heart rate and blood pressure and the thermoregulatory sweat test. Parasympathetic function was evaluated using heart rate response to deep breathing (R-R variability on EKG).
What was found
Thermoregulatory sweat test abnormalities occurred in 17/20 (85%) CVS patients versus 2/20 (10%) controls (P < 0.001). Postural tachycardia (standing heart rate increase > 30 bpm) was observed in 7/20 (35%) CVS patients versus 1/20 (5%) controls (P = 0.04). In total, 18/20 (90%) CVS patients had either abnormal sudomotor function, postural tachycardia, or both. Heart rate response to deep breathing was normal in 19/20 (95%) CVS patients and 18/20 (95%) controls.
Why it matters
The findings demonstrate that adult cyclic vomiting syndrome is frequently accompanied by sympathetic and sudomotor impairment, while parasympathetic cardiac control remains preserved.
Limits
Small sample size (20 cases, 20 controls). The case-control design cannot determine whether autonomic changes are etiologic, comorbid, or secondary to recurrent vomiting. The abstract does not specify whether testing occurred during interictal or acute phases or detail medication washouts.
Cited by
- supports The autonomic nervous system is dysregulated in patients suffering from gastrointestinal disorders such as chronic vomiting syndromes.