Probing Early Motion Processing With Eye Movements: Differences of Vestibular Migraine, Migraine With and Without Aura in the Attack Free Interval

Background.-Migraineurs, in between headache attacks, have a different sensitivity to sensory motion stimuli compared to non-migraineurs. Methods.-This cross-sectional laboratory study examines the motion processing in migraineurs using ocular following responses (OFR) elicited by large field random dot patterns and open-loop smooth pursuit eye movements (PS) elicited by a single target moving on a homogenous background. Eye movements were recorded with a video-oculographic system (EyeSeeTec (R)) and stimuli presented on a CRT at 100 Hz repetition rate to horizontal stimuli of a velocity of 2.5 to 160 degrees/s. Eye movements were analyzed during the open loop period. Results.-We recorded 43 migraine patients: 14 migraine with (MwA), 19 without aura (MwoA), 10 vestibular migraine (VM), and 16 healthy controls. ANOVA analysis of OFR responses amplitudes showed significant differences in the subgroup (control, MwA, MwoA, and VM) (F-3,F-409 =29.8, P<.001), stimulus velocity (F-6,F-406=12.6, P<.001), and interaction (F-18,F-394=1.9, P=.015). Fitting the OFR response velocity tuning by a Weibull function showed that the subgroups were different in the linear scaling factor (F-4,F-53=4.3, P<.001) but not in parameters defining the overall form of the tuning function. In contrast, the initial open-loop responses of PS were not changed compared to control for the three different migraine subgroups. Conclusion.-From the findings, we hypothesize that in the migraine subtypes, MwA and VM, there is different sensory motion information processing for OFR compared to MwoA and control, not explained by a neuronal hyperexcitability in V5. OFR might be a possible subclinical marker in the future to diagnose MwA and VM