A case of infratentorial meningioma causing spontaneous downbeat nystagmus. Case report and review of literatures.

Abstract

BACKGROUND\nSpontaneous downbeat nystagmus is a finding that raises suspicions of a central nervous system disorder. The vermis and the lower brainstem lesions are considered to be responsible, but the exact mechanism is still controversial. We observed a rare case of spontaneous downbeat nystagmus caused by an infratentorial meningioma.\n\n\nCASE DESCRIPTION\nA 50-year-old woman was incidentally diagnosed with infratentorial tumor. Later she suffered from oscillopsia and the symptom disturbed her daily life especially while driving. MRI showed a tumor of approximately 30mm in diameter at the dorsal midline of the posterior fossa. The tumor was compressing the cerebellar vermis and was apparently responsible for the symptoms that affected her daily life, so we decided to perform tumor removal. The postoperative course was uneventful, and the spontaneous downbeat nystagmus completely disappeared.\n\n\nCONCLUSIONS\nVertical nystagmus is a finding that raises suspicion of a central nervous system disorder, and requires detailed examination. In addition, incase of vertical nystagmus due to tumor compression of vermis, removal of the tumor can be an effective treatment.