High Resolution Magnetic Resonance Image of Duane’s retraction syndrome with 3D Fast Imaging Employing Steady-state Acquisition (FIESTA) sequence: three case reports

Reprint requests to: Dr. Te-Chang Wu Department of Radiology, Chi-Mei Foundation Hospital. No. 901, Chung Hwa Road, Yong-Kong, Tainan 710, Taiwan, R.O.C. Three children of unilateral type I Duane’s retract ion syndrome (DRS), aged 8 years, 14 months and 2 years were confirmed by demonstration of absence of ipsilateral abducens nerves on 3D fast imaging employing steady-state acquisition (FIESTA) MR sequence. The two younger patients had isolated abduction deficit without the characteristic globe retraction or upward/downward shooting on attempted adduction. The application of high-resolution MR imaging is useful for differential diagnosis and conf irmation of DRS, especially in patients without characteristic presentations. Duane’s retraction syndrome (DRS) is a rare congenital ocular motility disorder characterized by limited abduction and/or limited adduction. Other diagnostic manifestations include palpebral fissure narrowing, globe retraction and upward/downward shooting on attempted adduction. The most common cause is absence or hypoplasia of abducens cranial nerves and abducens nucleus ipsi lateral to the affected eyes. Aberrant innervation of lateral rectus muscle by a branch of oculomotor nerve causes globe retraction when attempted abduction. DRS is classified clinically by Heuber [1] into three types: type I comprised the majority of patients (80%) with limited ability of abduction; type II (7%) with limited ability of adduction and type III (15%) with limited ability of abduction and adduction. Diagnosis of DRS in a typical case is not difficult. However, in young children, correct diagnosis of DRS is more challenging because characteristic globe retraction and up-/downward shooting are not evident [2]. In this situation, image studies by demonstration of absence of abducens nerves on MRI may help for the correct diagnosis of DRS from other diseases such as abducens nerve palsy, Moebius' syndrome, congenital oculomotor apraxia, and congenital or infantile esotropia. Herein, we presented 3 young children of type I DRS, two of them had only isolated abduction deficit clinically, and all three patients had clear demonstration of absence of ipsilateral abducens nerve by 3D FIESTA sequences.