Neostigmine-induced alterations in fast phase of optokinetic responses in myasthenic ocular palsies

J Neurol. 2002 Jul;249(7):867-74. doi: 10.1007/s00415-002-0750-0.


Closed-loop and open-loop optokinetic nystagmus (OKN) eye movements were recorded with an electromagnetic scleral search coil in 16 patients with myasthenic ocular palsies, 8 patients with nonmyasthenic ocular palsies, and 4 normal controls. We calculated the summation of fast-phase amplitude per second (SFPAps), mean of fast-phase amplitude (MFPA) and mean of fast-phase peak velocity (MFPV) of OKN before and after administration of neostigmine. Under open-loop conditions, the myasthenic patients group demonstrated distinct increases in three parameters: SFPAps (P < 0.000001), MFPA (P < 0.001) and MFPV (P < 0.001) following neostigmine injection, and the increase in SFPAps was greater than those of MFPA and MFPV (P < 0.02), while the other two groups showed no significant increases. Under closed-loop condition, only five of the myasthenic patients showed significant changes. These results suggest that the change in SFPAps during open-loop OKN before and after neostigmine administration was a specific measurement that differentiated patients with myasthenic ocular palsies from the other groups.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Diagnosis, Differential
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myasthenia Gravis / complications*
  • Myasthenia Gravis / diagnosis
  • Neostigmine / pharmacology*
  • Nystagmus, Optokinetic / drug effects*
  • Oculomotor Nerve Diseases / etiology
  • Oculomotor Nerve Diseases / physiopathology*
  • Parasympathomimetics / pharmacology*


  • Parasympathomimetics
  • Neostigmine