We studied the effect of TV administration of a dehydroepiandrosterone
sulfate (DHEAS) preparation (200 mg/day for 8 weeks) in 11 patients w
ith myotonic dystrophy (MyD). After DHEAS, activities of daily Living
improved, muscle strength increased, and myotonia decreased. Conductio
n block and premature beats also improved in the four patients with ca
rdiac involvement. This pilot study may provide a rationale for a cont
rolled study of DHEAS in MyD.