Unilateral internuclear ophthalmoplegia revealing multiple sclerosis : a case report

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system of autoimmune origin. Depending on the site of brain lesions, MS patients can develop oculomotor disorders. Several disorders are described in the literature, the most common being internuclear ophthalmoplegia (INO) and dysmetric saccades [1]. In contrast to optic neuropathy, these oculomotor disorders are rarely indicative of the disease and appear most often during the course of MS [2]. Knowing the different structures responsible for the control of eye movements allows us to link each clinical oculomotor disorder to an anatomical localization. INO, the most common oculomotor disorder in MS, is related to a lesion of the medial longitudinal fasciculus (MLF) [3]. It is part of functional paralysis or gaze palsy, which is a disorder of eye movements attributed to midbrain alterations. We report in this article a case of MS revealed by unilateral INO.