TY - JOUR
T1 - Impaired fixation suppression of horizontal vestibular nystagmus during smooth pursuit
T2 - pathophysiology and clinical implications
AU - Korda, Athanasia
AU - Zee, David S.
AU - Wyss, Thomas
AU - Zamaro, Ewa
AU - Caversaccio, Marco D.
AU - Wagner, Franca
AU - Kalla, Roger
AU - Mantokoudis, Georgios
N1 - Funding Information:
Dr G. Mantokoudis was supported by the Swiss National Science Foundation (Grant #320030_173081). Dr D. Zee was supported by a Guest Professorship Grant, Inselspital Bern, University of Bern.
Publisher Copyright:
© 2021 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology
PY - 2021/8
Y1 - 2021/8
N2 - Background and purpose: A peripheral spontaneous nystagmus (SN) is typically enhanced or revealed by removing fixation. Conversely, failure of fixation suppression of SN is usually a sign of a central disorder. Based on Luebke and Robinson (Vision Res 1988, vol. 28 (8), pp. 941–946), who suggested that the normal fixation mechanism is disengaged during pursuit, it is hypothesized that vertical tracking in the light would bring out or enhance a horizontal SN. Methods: Eighteen patients with acute vestibular neuritis were studied. Eye movements were recorded using video-oculography at straight-ahead gaze with and without visual fixation, and during smooth pursuit. The slow-phase velocity and the fixation suppression indices of nystagmus (relative to SN in darkness) were compared in each condition. Results: During vertical tracking, the slow-phase velocity of horizontal SN with eyes near straight-ahead gaze was significantly higher (median 2.7°/s) than under static visual fixation (median 1.2°/s). Likewise, the fixation index was significantly higher (worse suppression) during pursuit (median 48%) than during fixation (median 26%). A release of SN was also suggested during horizontal pursuit, if one assumes superposition of SN on a normal and symmetrical pursuit capability.
AB - Background and purpose: A peripheral spontaneous nystagmus (SN) is typically enhanced or revealed by removing fixation. Conversely, failure of fixation suppression of SN is usually a sign of a central disorder. Based on Luebke and Robinson (Vision Res 1988, vol. 28 (8), pp. 941–946), who suggested that the normal fixation mechanism is disengaged during pursuit, it is hypothesized that vertical tracking in the light would bring out or enhance a horizontal SN. Methods: Eighteen patients with acute vestibular neuritis were studied. Eye movements were recorded using video-oculography at straight-ahead gaze with and without visual fixation, and during smooth pursuit. The slow-phase velocity and the fixation suppression indices of nystagmus (relative to SN in darkness) were compared in each condition. Results: During vertical tracking, the slow-phase velocity of horizontal SN with eyes near straight-ahead gaze was significantly higher (median 2.7°/s) than under static visual fixation (median 1.2°/s). Likewise, the fixation index was significantly higher (worse suppression) during pursuit (median 48%) than during fixation (median 26%). A release of SN was also suggested during horizontal pursuit, if one assumes superposition of SN on a normal and symmetrical pursuit capability.
KW - fixation suppression
KW - nystagmus
KW - pursuit
KW - vestibular
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U2 - 10.1111/ene.14909
DO - 10.1111/ene.14909
M3 - Article
C2 - 33983645
AN - SCOPUS:85107346857
VL - 28
SP - 2614
EP - 2621
JO - European Journal of Neurology
JF - European Journal of Neurology
SN - 1351-5101
IS - 8
ER -