title: Clinical presentation of pseudo-abducens palsy.
abstract: OBJECTIVE
  Pseudo-abducens palsy is a neurologic limitation in abduction with an intact abducens nerve. This rare condition can be observed when voluntary eye movements show impairment in lateral gaze, yet the vestibulo-ocular reflex (VOR) demonstrates full abduction. The intact VOR indicates the integrity of the infranuclear abducens nerve, thus suggesting that a pseudo-abducens palsy is likely caused by supranuclear pathology.
  
  
  METHODS
  A 63-year-old African American man presented with sudden-onset, binocular, horizontal diplopia. Extraocular motilities revealed a complete restriction of abduction OS on pursuits with intermittent spasm of the right medial rectus that was most evident in primary and left gazes. No cyclodeviation or vertical deviation was found. Doll's head maneuver was used to stimulate the VOR, which facilitated complete abduction OS, despite its gross limitation on pursuits. The intact VOR and impaired abduction on pursuits, coupled with contralateral esotropia, yielded a diagnosis of pseudo-abducens palsy.
  
  
  CONCLUSIONS
  Although considered to be a rare condition, it is important for the clinician to differentiate pseudo-abducens palsy from a classic abducens infranuclear palsy. Presented is a case displaying the typical features of a pseudo-abducens palsy, in conjunction with contralateral esotropia, which further supports the theory of a dysfunctional supranuclear vergence pathway.
authors.affiliation: *OD, FAAO †OD Salem Veterans Affairs Medical Center, Salem, Virginia (all authors); and Virginia Tech Carilion School of Medicine, Roanoke, Virginia (WSS).
authors.forename: Maya Sinulingga
authors.initials: MS
authors.lastname: Reid
authors.forename: Scott Alan
authors.initials: SA
authors.lastname: DePoe
authors.forename: Reagan Lorena
authors.initials: RL
authors.lastname: Darner
authors.forename: Jonathan Paul
authors.initials: JP
authors.lastname: Reid
authors.forename: William Scott
authors.initials: WS
authors.lastname: Slagle
mesh_terms: D020434:Abducens Nerve Diseases / Q000175:diagnosis* / Q000503:physiopathology; D004172:Diplopia / Q000175:diagnosis* / Q000503:physiopathology; D004948:Esotropia / Q000175:diagnosis* / Q000503:physiopathology; D005133:Eye Movements; D006801:Humans; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000503:physiopathology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology