A 35-year-old man who was referred to our hospital 6 days after diplopia, dizziness and left hemifacial palsy had experienced left facial palsy 8 years earlier. Ocular movement showed typical left one-and-a-half (OAH) syndrome; conjugate left-side lateral gaze palsy and impaired left-eye adduction and for the right eye, gaze nystagmus induction in the right-side gaze. Vertical eye movement and convergence were not disturbed. Pure-tone audiometry, auditory brain stem response (ABR) and vestibular evoked myogenic potential (VEMP) were within the normal range, while caloric tests showed canal paresis on both sides. T2-weighted magnetic resonance imaging (MRI) showed multiple high-intensity lesions in the paramedian pontine tegmentum and white matter close to the lateral ventricles, yielding a diagnosis of multiple sclerosis based on recurrent facial palsy and multiple lesions seen on MRI. Methylpredonisolone pulse therapy effectively removed left facial palsy completely within a week and ocular movement had normalized one month later. Careful evaluation of eye movement is a key in suspected brain lesion symptoms such as multiple sclerosis presenting a variety of neurological signs and symptoms.
