Paretic sideormal side ratios of cross-sectional areas of the superior oblique muscle vary largely in idiopathic superior oblique palsy.

摘要

I READ WITH INTEREST THE RECENT REPORT BY UCHIYAMA and associates of their magnetic resonance imaging study of superior oblique (SO) muscle cross-section in patients with unilateral SO palsy. These authors compared coronal plane magnetic resonance imaging (MRI) in 50 cases, and in 45 control subjects. The authors calculated the ratio of SO cross-section between the paretic and normal sides. The figure provided by these authors shows a very impressive scatter of data for SO palsy, yet very small 95% confidence intervals are superimposed on the data. For SO palsy in total, the 95% confidence intervals for the ratio are stated as ranging from 0.66 to 0.80. Nevertheless, all but 3 of their 49 unilateral cases lie outside of the 95% confidence interval. Of course, such an -occurrence is a statistical impossibility, because the idea of a 95% confidence interval is to encompass the great bulk of all observations.