Overview

• If present, internuclear ophthalmoplegia is highly suggestive of a lesion affecting the medial longitudinal fasciculus within the brainstem, which is involved in conjugate gaze.
• The most common causes of lesions in this area would be stroke (older patients) or multiple sclerosis (younger patients).

• • Look For

  • Inability to adduct one eye, with nystagmus in the other eye.

• • Causes of Internuclear Ophthalmoplegia

  • Multiple sclerosis
  • Ischaemic stroke
  • Trauma
  • Infection
  • Tumour
  • Haemorrhage
  • Vasculitis