Muscarinic antagonists in the treatment of acquired pendular and downbeat nystagmus: a double-blind, randomized trial of three intravenous drugs

Ann Neurol. 1994 Mar;35(3):319-25. doi: 10.1002/ana.410350312.


We performed a double-blind, randomized trial of intravenous scopolamine, benztropine, and glycopyrrolate in 7 patients with acquired nystagmus and oscillopsia. Five patients had pendular nystagmus and 2, downbeat nystagmus. We recorded eye movements with a magnetic search coil technique and tested visual acuity and motion perception before and after administration of each drug. Scopolamine reduced nystagmus in all patients. Benztropine was moderately effective and glycopyrrolate had a negligible impact. Visual acuity improved only with scopolamine; motion discrimination and oscillopsia improved significantly with scopolamine and benztropine. Pendular and downbeat nystagmus respond to intravenous antagonists of central muscarinic receptors.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Analysis of Variance
  • Benztropine / therapeutic use
  • Double-Blind Method
  • Glycopyrrolate / therapeutic use
  • Humans
  • Injections, Intravenous
  • Middle Aged
  • Nystagmus, Pathologic / drug therapy*
  • Nystagmus, Pathologic / physiopathology
  • Parasympatholytics / administration & dosage
  • Parasympatholytics / therapeutic use*
  • Scopolamine / therapeutic use
  • Vision, Ocular / drug effects


  • Parasympatholytics
  • Benztropine
  • Scopolamine
  • Glycopyrrolate