AUTHOR=Ling Xia , Wu Yue-Xia , Feng Yu-Fei , Zhao Tong-Tong , Zhao Gui-Ping , Kim Ji-Soo , Yang Xu , Wang Zhao-Xia 

TITLE=Spontaneous nystagmus with an upbeat component: Central or peripheral vestibular disorders?

JOURNAL=Frontiers in Neurology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1106084

DOI=10.3389/fneur.2023.1106084

ISSN=1664-2295

ABSTRACT=<sec><title>Objective</title><p>To determine the topical diagnosis and etiologies of spontaneous nystagmus (SN) with an upbeat component.</p></sec><sec><title>Methods</title><p>We retrospectively recruited 43 patients with SN with an upbeat component at a university hospital in China from 2020 to 2022. SN with an upbeat component was divided into pure upbeat nystagmus (UBN), SN with a predominant upbeat component, and SN with a non-predominant upbeat component. We analyzed their clinical and neurotologic findings and the final diagnosis.</p></sec><sec><title>Results</title><p>Fourteen (32.6%) of them showed pure UBN, while 29 (67.4%) exhibited SN mixed with an upbeat component, mixed upbeat-horizontal in 15, mixed upbeat-horizontal-torsional in 13, and upbeat-torsional in the remaining one. Pure UBN and SN with a predominant upbeat component were more common in central than in peripheral vestibular disorders [16 (80.0%) vs. 0 (0%), Chi-Square test, <italic>p</italic> &lt; 0.001]. Central vestibular disorders were diagnosed in 20 (46.5%) patients, peripheral in 14 (32.6%), and undetermined in nine (20.9%) patients. The underlying causes mainly included acute unilateral peripheral vestibulopathy (<italic>n</italic> = 11), posterior circulation infarction (<italic>n</italic> = 9), benign recurrent vertigo (<italic>n</italic> = 4), vestibular migraine (VM, <italic>n</italic> = 3), and VM of childhood (<italic>n</italic> = 2).</p></sec><sec><title>Conclusion</title><p>SN with an upbeat component can be seen in both central and peripheral vestibular disorders. Pure UBN was a characteristic sign of central vestibular dysfunction. Central vestibular disorders should be highly suspected when patients show pure UBN or SN with a predominant upbeat component.</p></sec>