Differential diagnosis of apogeotropic positional nystagmus in the emergency room

In the emergency room, the most common cause of dizziness is benign paroxysmal positional vertigo (BPPV) [1]. BPPV is usually diagnosed by a characteristic nystagmus. Horizontal direction-changing apogeotropic positional nystagmus (APN) in the supine head-roll test is one such nystagmus suggestive of BPPV (horizontal semicircular canal cupulolithiasis-type) [2]. Thus, dizzy patients with APN tend to be diagnosed with BPPV when they have no other obvious neurologic symptoms. However, APN is also known to be associated with cerebellar lesions [3].

from Journal of the Neurological Sciences https://ift.tt/2FO0FiO