Acute vertigo presenting with spontaneous horizontal nystagmus (SHN),Isolated hypofunction of a horizontal semicircular canal (HSC)

Isolated horizontal canal hypofunction differentiating a canalith jam from an acute peripheral vestibular loss

Publication date: March–April 2019

Source: American Journal of Otolaryngology, Volume 40, Issue 2

Author(s): Andrea Castellucci, Pasquale Malara, Cristina Brandolini, Valeria Del Vecchio, Davide Giordano, Angelo Ghidini, Gian Gaetano Ferri, Antonio Pirodda

Abstract

Objectives

To describe a unique case of acute vertigo presenting with spontaneous horizontal nystagmus (SHN) and a clinical picture consistent with right acute peripheral vestibular loss (APVL) in which an isolated hypofunction of a horizontal semicircular canal (HSC) permitted to detect a spontaneous canalith jam and treat the patient accordingly.

Methods

Case report and literature review.

Results

A 74-year old woman presented with acute vertigo, left-beating SHN and a clinical picture consistent with right APVL. Nevertheless, vestibular evoked myogenic potentials were normal with symmetrical amplitudes and the video head impulse test (vHIT) revealed an isolated hypofunction of the right HSC. After repeated head shakings, the supine roll test evoked bilaterally a positioning paroxysmal geotropic horizontal nystagmus suggesting benign paroxysmal positional vertigo involving the non-ampullated arm of the right HSC. vHIT and caloric testing confirmed restitution of HSC function after repositioning maneuvers.

Conclusions

In case of acute vertigo with SHN, a complete functional assessment of vestibular receptors and afferents should always be given in order to avoid misdiagnosis. Canalith jam should be considered in case of spontaneous nystagmus and isolated canal hypofunction.