[Skip to Content]
[Skip to Content Landing]
Article
July 1988

A Clinical Sign of Canal Paresis

Author Affiliations

From the Eye and Ear Unit, Department of Neurology, Royal Prince Alfred Hospital (Dr Halmagyi), and the Department of Psychology, University of Sydney (Dr Curthoys), Sydney, New South Wales, Australia.

Arch Neurol. 1988;45(7):737-739. doi:10.1001/archneur.1988.00520310043015
Abstract

• Unilateral loss of horizontal semicircular canal function, termed canal paresis, is an important finding in dizzy patients. To our knowledge, apart from head-shaking nystagmus, no clinical sign of canal paresis has yet been described and the term derives from the characteristic finding on caloric tests: little or no nystagmus evoked by either hot or cold irrigation of the affected ear. We describe a simple and reliable clinical sign of total unilateral loss of horizontal semicircular canal function: one large or several small oppositely directed, compensatory, refixation saccades elicited by rapid horizontal head rotation toward the lesioned side. Using magnetic search coils to measure head and eye movement, we have validated this sign in 12 patients who had undergone unilateral vestibular neurectomy.

×