Congenital Pendular Seesaw Nystagmus

ABSTRACT

Seesaw nystagmus refers to torsional nystagmus with dissociated vertical components. In this disorder, one eye goes up and intorts while the other one descends and extorts. We describe a 40-year-old man who presented with decreased vision due to pendular seesaw nystagmus. Brain MRI showed the empty sella and enlarged pituitary fossa. The delayed and decreased responses of the visual evoked potentials in the ipsilateral occipital lobe with monocular stimulation suggested unequal crossing of the optic pathways as an underlying mechanism.