title: Imaging demonstration of trochlear nerve agenesis in superior oblique palsy emerging during the later life.
abstract: BACKGROUND
  Congenital trochlear palsy may manifest with sudden vertical diplopia due to decompensation during the later life, which may bring a diagnostic challenge.
  
  
  METHODS
  Two men with vertical diplopia for several years after age of 50 were referred with persisting or suddenly aggravating diplopia. Findings were consistent with unilateral superior oblique palsy (SOP) in both patients with a contraversive head tilt. Facial asymmetry was suggestive of a congenital cause in a patient. High resolution magnetic resonance image (MRI)s disclosed atrophic superior oblique and absent trochlear nerve in the side of SOP in both patients.
  
  
  CONCLUSIONS
  Imaging demonstration of superior oblique atrophy and absent trochlear nerve may aid in diagnosis of congenital SOP presenting sudden vertical diplopia during the later life due to delayed decompensation.
authors.affiliation: Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: SeungHa
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, South Korea.
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, South Korea.
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Yang
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, South Korea.
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Hwang
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, South Korea.
authors.forename: Jae Hyoung
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, South Korea.
authors.forename: Ji-Soo
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, South Korea. Electronic address: nrpsh@snu.ac.kr.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Park
mesh_terms: D001284:Atrophy; D004172:Diplopia / Q000209:etiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009421:Nervous System Malformations / Q000150:complications / Q000473:pathology; D009801:Oculomotor Muscles / Q000473:pathology*; D014321:Trochlear Nerve / Q000002:abnormalities* / Q000473:pathology; D020432:Trochlear Nerve Diseases / Q000150:complications / Q000151:congenital* / Q000473:pathology
keywords: Agenesis; Congenital trochlear nerve palsy; Diplopia; Superior oblique atrophy