Abstract
Patients with vestibular migraine (VM) often report dizziness with changes in the head or body position. Such symptoms raise the possibility of dysfunction in neural mechanisms underlying spatial orientation in these patients. Here we addressed this issue by investigating the effect of static head tilts on errors of upright perception in a group of 27 VM patients in comparison with a group of 27 healthy controls. Perception of upright was measured in a dark room using a subjective visual vertical (SVV) paradigm at three head tilt positions (upright, ±20°). VM patients were also surveyed about the quality of their dizziness and spatial symptoms during daily activities. In the upright head position, SVV errors were within the normal range for VM patients and healthy controls (within 2° from true vertical). During the static head tilts of 20° to the right, VM patients showed larger SVV errors consistent with overestimation of the tilt magnitude (i.e., as if they felt further tilted toward the right side) (VM: −3.21° ± 0.93 vs. Control: 0.52° ± 0.70; p = 0.002). During the head tilt to the left, SVV errors in VM patients did not differ significantly from controls (VM: 0.77° ± 1.05 vs. Control: −0.04° ± 0.68; p = 0.52). There was no significant difference in SVV precision between the VM patients and healthy controls at any head tilt position. Consistent with the direction of the SVV errors in VM patients, they largely reported spatial symptoms toward the right side. These findings suggest an abnormal sensory integration for spatial orientation in vestibular migraine, related to daily dizziness in these patients.
Highlights
Vestibular migraine (VM) is the most common cause of dizziness and spatial disorientation with a lifetime prevalence of about 1% in the general population [1]
The mean subjective visual vertical (SVV) error in the upright position was within the normal range for both VM patients and controls (−0.25◦ ± 0.38) [9, 12], and it did not differ between the two groups (Student’s t-test with Bonferroni correction α = 0.0167; p = 0.17)
We investigated SVV errors during head tilt in patients who met the diagnostic criteria for vestibular migraine
Summary
Vestibular migraine (VM) is the most common cause of dizziness and spatial disorientation with a lifetime prevalence of about 1% in the general population [1]. Patients with vestibular migraine often complain of symptoms triggered by these changes, raising the possibility of dysfunction in neural mechanisms underlying orientation constancy [1] Such perceptual dysfunction can be studied by measuring perception of upright in a psychophysical task known as the subjective visual vertical (SVV) [8, 9]. This separation of the sensory reference frames introduces a challenge for the brain, especially in the absence of visual cues, when it has to rely on information about the head (in space) and eye (in head) positions to determine upright orientation Such processing demand is reflected by the systematic SVV errors during head tilt [9]. SVV errors are usually in the direction of the head tilt, reflecting undercompensation for the amount of tilt and underestimation of upright orientation relative to the head position (known as the A-effect) [9, 15, 16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
