Periodic Alternating Nystagmus Associated with Chiari-1 Malformation and Syringomyelia

Periodic alternating nystagmus(PAN) is a form of spontaneous nystagmus with a specific pattern. It may be of congenital origin in many cases, and may be related to vestibulo-cerebellar system disease. It usually causes not only many ophthalmic problems such as decreased vision but also neurologic symptoms such as ataxic gait. So, ophthalmologist must perform both ophthalmic and neurologic examinations. Nystagmus can be treated with muscle relaxant. We report our experience about 30-year-old woman who complained of involuntary ocular movement and ataxic gait, and were diagnosed as PAN associated with Chiari-1 malformation and syringomyelia through electronystagmography and brain MRF.