Analysis on the changes of palpebral fissure caused by neostigmine test with videonystagmography / 中华神经科杂志

ABSTRACT

Objective To quantitatively analyze the palpebral fissure changes in the neostigrnine tests with videonystagmography.Methods Thirty-five patients with myasthenia gravis ( MG),21 non-MG patients and 23 healthy volunteers were intramuscular injected with neostigmine methylsulfate(0.02 mg/kg) and atropine(0.5 mg).The width of palpebral fissure was measured before and after the injection for one hour( once every 10 minutes).The differences of palpebral fissure width of each time point within each group and between groups were analyzed quantitatively with repetitive measure ANOVA.Results There was a significant difference of palpebral fissures (mm) width at different time points within the MG group( before the test:4.67 ± 1.87,after the test:10 min:0.88 ±0.96,20 min:1.49 ± 1.38,30 min:1.71 ± 1.53,40 min:1.77 ± 1.82,50 min:1.79 ± 1.52,60 min:1.62 ± 1.68 ; F =11.202,P =0.002).There were also significant changes of palpebral fissures width in the MG group compared to the non-MG group and the normal control group (F =15.569,P ＜ 0.01; F =15.104,P ＜ 0.01 ).There was alsostatistical significance in the rate of change between these groups.Receiver operating characteristic analytical procedure indicated that 1.17 mm or 17.5％ was of better diagnostic capability in the neostigmine test.Conclusions Measuring palpebral fissure width with videonystagmography could be seen as an objective and accurate method.A patient with palpebral fissure width higher than 1.17 mm or 17.5％ should be highly suspected as MG.