title: Fourth and sixth cranial nerve injury after halo traction in children: a report of two cases.
abstract: BACKGROUND
  Spinal traction is the application of a longitudinal force to the spinal column as a means of stabilizing a damaged or abnormal spine. Although not well documented in the ophthalmic literature, complications include cranial nerve palsies, with the sixth nerve being most commonly affected. Fourth nerve palsies have not previously been reported to our knowledge. We present 2 cases of combined fourth and sixth palsies after cervical traction.
  
  
  METHODS
  Retrospectively, we reviewed the ophthalmic findings in 2 children with diplopia after spinal traction.
  
  
  RESULTS
  Case 1 suffered a traumatic rotatory atlantoaxial subluxation and underwent halo traction. Case 2 required traction to correct a scoliosis secondary to osteogenesis imperfecta. In both cases, sixth nerve palsies were apparent soon after traction. Careful orthoptic examination revealed additional fourth nerve involvement. After 3 months, both cases showed partial resolution of the cranial nerve injuries.
  
  
  CONCLUSIONS
  Cranial nerve injury may occur with spinal traction. Fourth nerve palsy may be underreported because of masking by a coinciding sixth nerve palsy.
authors.affiliation: Department of Ophthalmology, Great Ormond Street Hospital for Children, London, United Kingdom.
authors.forename: Emma
authors.initials: E
authors.lastname: Pinches
authors.forename: Dominic
authors.initials: D
authors.lastname: Thompson
authors.forename: Hilali
authors.initials: H
authors.lastname: Noordeen
authors.forename: Alki
authors.initials: A
authors.lastname: Liasis
authors.forename: Ken K
authors.initials: KK
authors.lastname: Nischal
mesh_terms: D020222:Abducens Nerve Injury / Q000209:etiology*; D000293:Adolescent; D002648:Child; D004172:Diplopia / Q000209:etiology*; D005260:Female; D006801:Humans; D012600:Scoliosis / Q000628:therapy; D013124:Spinal Injuries / Q000000981:diagnostic imaging / Q000628:therapy; D014057:Tomography, X-Ray Computed; D014143:Traction / Q000009:adverse effects*; D020432:Trochlear Nerve Diseases / Q000209:etiology*; D061247:Trochlear Nerve Injuries