Comparison of the esophageal manometric characteristics of idiopathic and reflux-associated esophageal spasm: Evaluation by 24-hour ambulatory esophageal motility and pH monitoring

Diffuse esophageal spasm (DES) is a typical esophageal dysfunction, but its cause is unknown. DES has been classified into reflux-associated esophageal spasm (RDES), caused by acid exposure, and idiopathic esophageal spasm (IDES), of unknown causes. The differences in esophageal motility pattern between the RDES and IDES are clues to elucidating the pathogenesis of DES. Although 24-hr ambulatory esophageal motility and pH monitoring is considered a feasible method for evaluating gastroesophageal reflux and esophageal function, most researchers previously defined the RDES as DES accompanied by esophagitis and heartburn using standard manometry over a short time frame. To clarify the pathogenesis of RDES, we did this research using 24-hr ambulatory esophageal motility and pH monitoring. The investigation included 25 normal controls and 116 patients with upper digestive symptoms. Among the 116 patients, 45 had DES (11 RDES, 30 IDES, and DES-GERD coexistence). Patients with RDES showed a significantly higher frequency of simultaneous contractions than did patients with IDES. Heartburn has been said to be peculiar to RDES, but also occurred in 12.5% of IDES. No significant differences in the mean pH of the esophagus during acid reflux were found between the RDES and IDES patients. Based on the results, we have proposed a refined definition of RDES.