Abstract

Periodic alternating nystagmus (PAN) is characterized by a periodical reversal in the direction of the nystagmus. Acquired PAN is caused by lesions of the inferior cerebellar vermis, causing disinhibition of the velocity storage mechanism, which is mediated by the vestibular nuclei. An eighty-year-old woman with abscess in midline cerebellum experienced dizziness and imbalance. We observed short period PAN with 7?8 seconds.

• Keywords: Periodic alternating nystagmus;Cerebellum;Abscess;