Open-loop and closed-loop optokinetic nystagmus (OKN) in myasthenia gravis and nonmyasthenic subjects.
Optokinetic nystagmus (OKN) eye movements of myasthenia gravis (MG) and nonmyasthenic ocular palsies, and normal subjects were examined under closed-loop and open-loop conditions. The open-loop OKN condition was achieved by adding the signal of eye-movement velocity of OKN to the computer-generated signal controlling the stimulus grating moving. The OKN was recorded by means of electromagnetic search scleral coil technique. In MG patients, the open-loop gains of OKN increased significantly after the intramuscular injection of an acetylcholinesterase inhibitor, neostigmine, while the closed-loop OKN gains were not significantly changed. Both the closed-loop and open-loop OKN gains of normal subjects and nonmyasthenic patients were not increased for the administration of neostigmine. The experimental results indicated that the open-loop OKN gain could be sensitive to reflect the changes of the function of neuromuscular junction in MG patients.
Yang
Q
Q
Laboratory of Neurobiology of Shanghai Institute of Physiology and Laboratory of Visual Information Processing of Biophysics Institute, Shanghai, 200031, China.
Wei
M
M
Sun
F
F
Tian
J
J
Chen
X
X
Lu
C
C
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D009388:Neostigmine / Q000494:pharmacology; D009469:Neuromuscular Junction / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D017120:Nystagmus, Optokinetic / Q000187:drug effects / Q000502:physiology*; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D009801:Oculomotor Muscles / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology
D009388:Neostigmine