Myasthenia gravis: rarity of gallstone formation

There is an increase in the production of gallbladder stones (cholelithiasis) following gastrectomy associated with vagotomy; we hypothesized that in the presence of constant stimulation of the vagal system, there should be decreased production of gallstones. Forty-two myasthenia gravis patients taking continuous anticholinesterase medications underwent ultrasound study of the gallbladder; only one patient, aged 62, had gallstones. In the control group of 112 nonmyasthenics matched for age and ethnic origin, 45 had stones. This study suggests that cholinergic medications protect against gallstones.