internuclear ophthalmoplegia (INO)

Etiology

• lesions of the medial longitudinal fasciculus
• especially in association with multiple sclerosis

Clinical manifestations

• failure of adduction (one eye) on horizontal gaze
  • nystagmus of abducting eye
• retention of convergence

More general terms

• ophthalmoplegia (ophthalmoparesis)

Additional terms

• medial longitudinal fasciculus (MLF)
• multiple sclerosis (MS); includes clinically isolated syndrome