Clinical and MRI findings of patients with internuclear ophthalmoplegia

Internuclear ophthalmoplegia (INO) is a distinctive ocular motor disorder resulting from dysfunction of the medial longitudinal fasciculus, which lies in the pontine tegmentum. We retrospectively analyzed clinical and magnetic resonance imaging (MRI) findings for four consecutive patients with internuclear ophthalmoplegia who were treated in our hospital. The causes of the disease were cerebral infarction in three cases and multiple sclerosis in one case. Vertigo and facial nerve palsy were associated in three cases and one case, respectively. MRI studies visualized an ischemic lesion in the responsible portion of the brainstem in one patient but failed to reveal responsible lesions in the other three patients. All the patients completely recovered in 1 to 22 days, with an average recovery period of 9.3 days. The etiology, diagnosis and management of INO were bibliographically reviewed.