Down-beat nystagmus: case report with magnetic resonance imaging and surgical treatment

A woman with down-beat nystagmus (DBN) underwent magnetic resonance imaging (MRI), which showed a syringo-myelic cyst in the medulla. Surgical treatment of the cyst ended the abnormal eye movement. This case demonstrates the use of MRI for the diagnosis of DBN. It also shows the value of surgical treatment when a cyst is responsible for this symptom, as in Arnold-Chiari malformation. (Neurosurgery 21:736-739, 1987)