Solid phase radionuclide esophageal motility in polymyositis and dermatomyositis

Abstract

Polymyositis (PM) and dermatomyositis (DM) may be associated with motor dysfunction of the entire gastrointestinal tract. Abnormal esophageal motor function is a well-recognized complication of these diseases. In this study, we used a solid phase esophageal study to evaluate the motor function in patients with PM or DM. Twenty-three patients and 36 age-matched normal volunteers were studied. Each subject was placed in a supine position above a gamma camera linked to a computer and was given a 4-ml bolus of solid gelatin containing 1 mCi of Tc-99m phytate. Data were acquired in the list mode. A computer method modified from Kelim and Wald and Russell et al. was used to calculate the following: A) total mean transit time (MTT); B) residual fraction after the first swallow (RF); and C) retrograde index (RI). All values are presented as mean +/- standard deviation (SD). The Student's t-test was used to test statistical significance. Our preliminary results suggest: 1) delayed esophageal emptying is common (17/23) in PM/DM, indicating frequent malfunction of the smooth muscle of the upper gastrointestinal tract in PM/DM and 2) measurement of esophageal motility may monitor disease activity in PM/DM.