A Case of Bilateral Internuclear Ophthalmoplegia with No Brain Stem Lesion

ABSTRACT

PURPOSE: Bilateral internuclear ophthalmoplegia (INO) has been reported mostly in bilateral medial longitudinal fasciculus (MLF) lesion. To report a case who presented with typical bilateral internuclear ophthalmoplegia (INO) with no brainstem lesion on brain MRI. METHODS: Case presentation. RESULTS: Seventy two year-old woman presented with bilateral marked adduction limitation and diplopia. Bilateral marked adduction limitation did not cross midline. Nystagmus occured in abducting eye. Elevation and depression were normal in duction. Transcranial doppler revealed moderated stenosis of right internal carotid artery and severe stenosis of left intracranial internal carotid artery. Brain MRI revealed focal old infarction of right corona radiata and circumscribed acute infarction at more upper level of corona radiata, however, no pathologic finding was identified in brainstem. Initial severe exotropia was improved to 30 PD exotropia in primary position. Adduction limitation was markedly improved 2 months later but bilateral horizontal nystagmus in abducting eye persisted