Intermittent positional downbeat nystagmus of cervical origin Yasuo Ogawa *, Shigeto Itani, Koji Otsuka, Taro Inagaki, Shigetaka Shimizu, Takahito Kondo, Nobuhiro Nishiyama, Noriko Nagai, Mamoru Suzuki Department of Otorhinolaryngology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo, Japan 1. Introduction Positional down-beat nystagmus (p-DBN) is typically a clinical sign of central nervous system involvement. It occurs with lesions in the vestibulocerebellum or the craniocervical junction and with drug intoxication [1]. Experimental extirpation of the nodulus in the cat has been shown to cause postural DBN [2]. Occasionally, p- DBN is seen in patients without CNS involvement [1,3]. There is one report showing that canalithiasis of the anterior semicircular canal (ASC) causes p-DBN [4]. It is difficult to distinguish the origin of the p-DBN in the peripheral or central nervous system. Intermittent p-DBN is extremely rare. We encountered a patient with p-DBN due to rotation and bending of the neck, which led us to suspect a cervical origin. In this report, we describe the features of neuro-otological findings, including nystagmus, and the clinical course. 2. Case report A 59-year-old man complained of brief positional vertigo for 1 year and a feeling of passing out when he looked down to lift a piece of luggage. He also felt the vertigo when his head turned to the left while lying down. He visited our clinic in May 2011. There was no spontaneous or gaze nystagmus. The positional test revealed p-DBN in the left lateral position without head rotation (Fig. 1). The test also showed p-DBN with head rotation to the left (Figs. 1 and 2), but there was no nystagmus in the supine position or right ear down position. The p-DBN was also observed in the bending forward position. No nystagmus was evoked by changing position from the head hanging position to the sitting position. We carried out the examination in the sitting position, during neck torsion to the left, and p-DBN was not seen. However, during a strong twist of the neck to the left in the sitting position, the patient complained of a feeling of passing out. Therefore, vascular insufficiency was also thought to occur in the sitting position. His hearing was normal bilaterally. There was no neuro- otological dysfunction and no cerebellar symptoms. Eye move- ment examinations, including the eye tracking test and the optokinetic nystagmus test, were normal. The caloric test with cold water at 10 8C and the visual suppression test were normal. Cervical and ocular vestibular evoked myogenic potentials were normal bilaterally. The subjective visual vertical test was normal. There were no abnormal findings in the brainstem, cerebellum, or inner ear on brain MRI. On MRA, the left vertebral artery (VA) was narrower than the right VA, but there was no stenosis in the VA bilaterally (Fig. 3). We presumed that the cause of the DBN was not from a central nervous system disorder, because the MRI, MRA, and electronystagmography were normal. We suspected cervical vertigo and performed the body rotation test without neck Auris Nasus Larynx 41 (2014) 234–237 A R T I C L E I N F O Article history: Received 25 April 2013 Accepted 20 September 2013 Available online 24 October 2013 Keywords: Positional nystagmus Cervical vertigo Nodulus Vestibulocerebellum A B S T R A C T Intermittent positional down beat nystagmus (p-DBN) is rare. We describe an unusual case of intermittent p-DBN which was induced by rotation, anteflexion, and lateral flexion of the neck. A 59- year-old man complained of loss of consciousness and lightheadedness. Positional testing revealed the p-DBN. The evoked p-DBN had latency and the patient had a feeling of passing out while the p-DBN was present. There were no abnormal findings in the vestibular functional examinations. Findings of the MRI were negative. MRA revealed no stenosis of the vertebral artery bilaterally, but there was an anatomical difference. The p-DBN characteristics were documented by electronystagmography during the positional test. The p-DBN lasted intermittently while maintaining the provoking position. It was found that p-DBN occurred with not only the rotation of the neck, but also in the anteflexion and lateral flexion of the neck. There was no stenosis of the vertebral artery (VA) on angiography, but we speculated that the cause of the p-DBN was the VA occlusion due to rotation, anteflexion, and lateral flexion of the neck. ß 2013 Elsevier Ireland Ltd. All rights reserved. * Corresponding author. Tel.: +81 3 3342 6111; fax: +81 3 3346 9275. E-mail address: y-ogawa8@tokyo-med.ac.jp (Y. Ogawa). Contents lists available at ScienceDirect Auris Nasus Larynx jo u rn al h om epag e: ww w.els evier.c o m/lo cat e/anl 0385-8146/$ – see front matter ß 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.anl.2013.07.012