Article Text

Download PDFPDF
Internuclear ophthalmoplegia
  1. Jonathan D Virgo1,2,
  2. Gordon T Plant1,2,3
  1. 1Moorfields Eye Hospital, London, UK
  2. 2St Thomas’ Hospital, London, UK
  3. 3The National Hospital for Neurology & Neurosurgery, London, UK
  1. Correspondence to Dr Jonathan D Virgo, Neuro-Ophthalmology, Moorfields Eye Hospital NHS Trust, 162 City Road, London EC1V 2PD, UK; j.d.virgo{at}


A brainstem lesion of any type that involves the medial longitudinal fasciculus (MLF) can cause internuclear ophthalmoplegia (INO). This primarily affects conjugate horizontal gaze and classically manifests as impaired adduction ipsilateral to the lesion and abduction nystagmus contralateral to the lesion. Here, we describe the anatomy of the MLF and review the clinical features of INO. We also describe conjugate horizontal gaze palsy and some of the ‘INO-plus’ syndromes.

  • Internuclear ophthalmoplegia
  • medial longitudinal fasciculus

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Contributors The manuscript is written by JDV and reviewed by GTP with corrections. Diagrams are produced by JDV. Animations are produced by Emma Plant. MR images are provided by Dr Indran Davagnanam (UCL Neuroradiology) and Professor Janice Holton (UCL Brain Bank).

  • Competing interests None declared.

  • Provenance and peer review Commissioned; externally peer reviewed. This paper was reviewed by Christian Lueck, Canberra, Australia.

Other content recommended for you