Spontaneous inversion of nystagmus without a positional change in the horizontal canal variant of benign paroxysmal positional vertigo

Article type: Research Article

Authors: Ogawa, Yasuo^* | Ichimura, Akihide | Otsuka, Koji | Hagiwara, Akira | Inagaki, Taro | Shimizu, Shigetaka | Nagai, Noriko | Itani, Shigeto | Suzuki, Mamoru

Affiliations: Department of Otorhinolaryngology, Tokyo Medical University, Tokyo, Japan

Correspondence: [*] Corresponding author: Yasuo Ogawa, Department of Otorhinolaryngology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo, Japan. Tel.: +81 3 3342 6111; Fax: +81 3 3346 9275; E-mail:y-ogawa8@tokyo-med.ac.jp

Abstract: OBJECTIVE: We investigated the neuro-otological findings, including nystagmus, and the clinical course of patients with the horizontal canal variant of benign paroxysmal positional vertigo (HC-BPPV), who showed spontaneous inversion of nystagmus without a positional change. Furthermore, we speculated on the possible mechanism of spontaneous inversion of nystagmus without a positional change. PATIENTS AND METHODS: The characteristics of spontaneous inversion of positional nystagmus without a positional change were analyzed in 7 patients with HC-BPPV. RESULTS: All patients were diagnosed as having HC-BPPV. During the positional test, the spontaneous inversion of nystagmus was observed in the same head position in all patients. Spontaneous inversion was observed on both sides in 5 patients, and only on 1 side in 2 patients. All patients presented with geotropic nystagmus in the first phase, and ageotropic nystagmus in the second phase. CONCLUSIONS: The coexistence of cupulolithiasis and canalolithiasis appears to be a possible mechanism of the spontaneous inversion of positional nystagmus.

Keywords: Horizontal canal BPPV, lateral canal BPPV, positional nystagmus, benign paroxysmal vertigo

DOI: 10.3233/VES-150552

Journal: Journal of Vestibular Research, vol. 25, no. 3-4, pp. 169-175, 2015