Three Similar But Unique Cases Of Isolated Superior Rectus ExtraOcular Muscle (EOM) Palsy Strabismus, Presenting With Large Abnormal Head Tilts (Postures, AHP).

Purpose: To report 3 rare cases, seen over 15 years, of isolated superior rectus (SR) palsy in binocularly fusing pediatric patients presenting with appropriate head tilts.

Patients and method: All 3 children, ages 11, 16, and 34 mos, presented with large right head tilts and secondary overactions of the right inferior oblique indicating LSR palsy. All 3 children received recessions of the antagonist left inferior rectus (LIR) 8 to 9 mm with 3 mm of nasal transposition to prevent exotropia in down gaze.

Results: All 3 children had zero head tilt 4 weeks after their LIR recessions of 8 to 9 mm, but all 3 children developed a significant contralateral left head tilt three months after their LIR recessions. Two of the 3 them three-stepped to produce a pattern of (previously occult) SR palsy. These 2 received recessions of the RIR 5.8 to 6.5 mm. One of the 3 had a pattern that indicated LIR weakness; his LIR was advanced 2.5 mm from a 9 mm recession to a 6.5 mm recession. No significant head tilts remained or developed anew after the second surgery, but two of the three cases eventually developed apparent primary overactions of the inferior obliques and received successful weakening procedures of the inferior obliques. Due to inclusion in each case of special handling of the intermuscular septa and Lockwoods ligament (for details see later text), none of the 3 children had lower lid retraction after the large IR recessions.

Conclusions: In view of the fact that the superior division of the Third Cranial Nerve also innervates the adjacent levator and these three cases have had no blepharoptosis suggests that these apparently palsied superior rectus muscles may have been congenitally hypoplastic. Classic MRI (Magnetic Resonance Imaging) of the EOM by the techniques of Demer, to confirm this hypothesis, have not been available in these children, because of the current technical limitations of such diagnostic imaging in the case of young children who cannot maintain steady fixation for the time required.