A MAGNETIC-RESONANCE-IMAGING STUDY OF DOUBLE ELEVATOR PALSY

Objective: The pathophysiology of double elevator palsy is poorly unde rstood. We assessed two patients with this condition using magnetic re sonance imaging (MRI) to evaluate the appearance of the extraocular mu scles. Design: Cross-sectional study. Setting: Radiology department of a university-affiliate hospital in London, Ont. Patients: Two patient s from a private ophthalmology practice who had undergone complete tra nspositions of the horizontal rectus muscles to treat hypotropia assoc iated With double elevator palsy, Intervention: MRI. A volume scanning technique was used to obtain maximum information about the muscles. O utcome measure: Appearance of the extraocular muscles. Results: In bat h patients MRI showed decreased volume of the superior rectus muscle o n the affected side. the other rectus muscles were normal. this sugges ted either congenital hypoplasia or paresis of the involved superior r ectus muscle. In addition, the lull tendon transpositions of the media l and lateral recti did nor appreciably change the middle and deep orb ital pathways of the transposed horizontal rectus muscles, Conclusions : MR1 may be a useful adjunct to saccadic velocity assessments in diff erentiating between primary inferior rectus restriction, primary super ior rectus paresis and congenital supranuclear elevator deficiency.