PT - JOURNAL ARTICLE AU - Lee, Sun-Uk AU - Choi, Jeong-Yoon AU - Kim, Hyo-Jung AU - Kim, Ji-Soo TI - Recurrent spontaneous vertigo with interictal headshaking nystagmus AID - 10.1212/WNL.0000000000005689 DP - 2018 Jun 12 TA - Neurology PG - e2135--e2145 VI - 90 IP - 24 4099 - http://n.neurology.org/content/90/24/e2135.short 4100 - http://n.neurology.org/content/90/24/e2135.full SO - Neurology2018 Jun 12; 90 AB - Objective To define a disorder characterized by recurrent spontaneous vertigo (RSV) of unknown etiology and interictal headshaking nystagmus (HSN).Methods We characterized HSN in 35 patients with RSV-HSN compared to that recorded in randomly selected patients with compensated vestibular neuritis (VN), vestibular migraine (VM), and Ménière disease (MD).Results The estimated time constant (TC) of the primary phase of HSN was 12 seconds (95% confidence interval [CI] 12–13) in patients with RSV-HSN, which was larger than those in patients with VN (5 seconds, 95% CI 4–5), VM (5 seconds, 95% CI 5–6), or MD (6 seconds, 95% CI 5–6). TCs of the horizontal vestibulo-ocular reflex were also larger during the rotatory chair test in patients with RSV-HSN. Among the 35 patients with RSV-HSN, 7 showed vigorous long-lasting HSN with a peak slow-phase velocity >50.0°/s. In 5 patients (5 of 7, 71%) with vigorous HSN, HSN could have been induced even with headshaking for only 2 to 5 seconds. Long-term prognosis was favorable, with a resolution or improvement of the symptoms in more than half of the patients during the median follow-up of 12 (range 2–58) years from symptom onset. None developed VM, MD, or cerebellar dysfunction during the follow-up.Conclusion The clinical features and characteristics of HSN in our patients indicate a hyperactive and asymmetric velocity-storage mechanism that gives rise to intermittent attacks of spontaneous vertigo probably when marginal compensation of underlying pathology is disrupted by endogenous or exogenous factors.BRV=benign recurrent vertigo; CI=confidence interval; HIT=head-impulse test; HSN=headshaking nystagmus; MD=Ménière disease; MR=magnetic resonance; MSSQ=motion sickness susceptibility questionnaire; RSV=recurrent spontaneous vertigo; SPV=slow-phase velocity; TC=time constant; VM=vestibular migraine; VN=vestibular neuritis; VOR=vestibulo-ocular reflex; VSM=velocity-storage mechanism