title: [MRI in Duane retraction syndrome: Preliminary results].
abstract: BACKGROUND
  Duane retraction syndrome (DRS) is a congenital ocular motility disorder with innervational dysgenesis. MRI improves our understanding of this disease by providing in vivo access to nerves and oculomotor muscles. The goal of this prospective study (2000-2008) was to analyze DRS clinically and neuroradiologically.
  
  
  METHODS
  Twenty-four patients (27 eyes) received a complete ophthalmologic evaluation and a brain-orbital MRI. The average age was 6.1 years. MRI was performed with 3D T2 CISS-weighted images through the brainstem to visualize the cisternal segments of the cranial nerves and the orbit (lateral and medial recti muscles). MRI anomalies were classified according to type I, II, and III and depending on their condition in the posterior fossa (absence, hypoplasia) and in the orbit (muscle anomalies).
  
  
  RESULTS
  Of 27 eyes, 70% were type I, 19% type II, and 11% type III. MRI showed abducens nerve abnormalities in 93% of the cases (78% absence) and muscle abnormalities in 57.5% of the cases. A detailed description showed 100% abducens nerve abnormalities and 58% abnormal lateral rectus muscle in type I, 60% abducens nerve abnormalities and 60% abnormal lateral rectus muscle in type II, and 100% abducens nerve abnormalities and 66% abnormal lateral rectus in type III.
  
  
  CONCLUSIONS
  This study presents two major findings: detection of abducens nerve abnormalities in most cases of DRS whatever the type, associated with muscle abnormalities, and the confirmation that this absence may exist in type II (2/5). Thus MRI proved to be a valuable tool for investigating these patients, improving the comprehension of the physiopathogenics of this disease.
authors.affiliation: Département d'ophtalmologie pédiatrique, service d'ophtalmologie, hôpital Nord, CHU de Marseille, chemin des Bourrely, 13015 Marseille, France. daniele.denis@ap-hm.fr
authors.forename: D
authors.initials: D
authors.lastname: Denis
authors.forename: M
authors.initials: M
authors.lastname: Cousin
authors.forename: E
authors.initials: E
authors.lastname: Zanin
authors.forename: E
authors.initials: E
authors.lastname: Toesca
authors.forename: N
authors.initials: N
authors.lastname: Girard
mesh_terms: D002648:Child; D004370:Duane Retraction Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies