Internuclear ophthalmoplegia in 14 patients: Clinical and topographic correlation using magnetic resonance imaging

Abstract

In a clinicotopographic study of 14 patients with internuclear ophthalmoplegia (INO) confirmed by electrooculography (EOG), the pattern of visual dysfunction was compared to the location and severity of lesions of the medial longitudinal fasciculus (MLF) visualized by magnetic resonance imaging (MRI). Of the 12 patients with classically-defined 'anterior' INO, nine were classed as having definite multiple sclerosis (MS), and three as probable or possible. Five of the 12 had MR-imaged MLF lesions, and five including one with MLF lesions, had cerebellum-associated lesions. Of the two patients with so-called 'posterior' INO, one presented a heredodegenerative disease and cerebellum-related lesions, and in the other, a non-visual neurological condition was not diagnosed. The finding that MR-imaged MLF lesions do not always occur simultaneously with INO may indicate that INO could be the expression of a functional disorder in the posterior fossa, preceding MLF lesion development.

Key Words:

• internuclear ophthalmoplegia
• magnetic resonance imaging
• medial longitudinal fasciculus
• electrooculography