An unusual variant of the dorsal midbrain syndrome in MS: clinical characteristics and pathophysiologic mechanisms.

Journal: Multiple Sclerosis (Houndmills, Basingstoke, England)
Published:
Abstract

Patients with MS exhibit a broad diversity of ocular motor syndromes. We describe a patient with relapsing-remitting MS who developed an unusual variation of the dorsal midbrain syndrome, characterized by monocular convergent-retraction nystagmus in the right eye, accompanied by divergent-retraction nystagmus in the fellow eye upon attempted upward gaze. Examination also revealed a skew deviation with a left hyperdeviation and severe adduction limitation in the left eye during attempted right gaze. We propose that a left INO accounted for the inability of the left eye to adduct (and result in convergent-retraction) during attempted upward saccades. We consider the pathophysiologic mechanisms responsible for our observations and review important details of the dorsal midbrain ocular motor circuitry.

Authors
Elliot Frohman, Richard Dewey, Teresa Frohman