Loss of vision alone may result in seesaw nystagmus

A patient is described who developed seesaw nystagmus (SSN) associated with progressive severe vision loss due to cone-rod dystrophy. She was otherwise neurologically normal, and findings on magnetic resonance imaging of the brain were normal, including optic chiasm, meso-diencephalic junction, and brainstem. The literature is reviewed on neurologically normal patients with SSN and ocular vision loss, and the hypothesis is presented that SSN may become manifest as a result of vision loss alone, even in patients with chiasmal lesions, without disruption of central ocular motility pathways.