Primary position upbeating nystagmus associated with middle ear disease

Abstract

Primary position upbeat nystagmus is a rare oculomotor sign which has previously been associated with central neurological disease, in particular, lesions of the pontine tegmentum. The authors report three patients with upbeat nystagmus who had chronic ear disease associated with deafness and vertigo. All three patients had normal brainstem appearances on NMR imaging. In one patient with positional upbeat nystagmus the nystagmus was abolished by osseous labyrinthectomy and was attributed to disease of the peripheral otolith organ. In the two remaining patients, the nystagmus persisted to a variable extent after middle fossa vestibular neurectomy, in one case, and tympanomastoid surgery in the other, and was attributed to a failure of vestibular compensation in the face of fluctuating peripheral function and of poor visual suppression of nystagmus.

Key Words:

• upbeat nystagmus
• mastoiditis
• labyrinthectomy