Quantitative pupillometry as a marker of autonomic dysregulation in vestibular migraine

Vestibular migraine (VM) has been associated with altered central sensory processing; however, objective measures of autonomic involvement remain insufficiently characterized. Quantitative pupillometry enables standardized assessment of both static and dynamic pupil responses. This study compared pupillary parameters between patients with VM and healthy controls under controlled illumination conditions.

Seventy participants were enrolled, including 40 patients diagnosed with VM according to the International Classification of Headache Disorders, 3rd edition (ICHD-3) criteria, and 30 age- and sex-matched controls. Bilateral pupillometry was performed using an automated infrared system under scotopic, mesopic, low photopic, high photopic, and resting light conditions. Static pupil diameter and dynamic parameters (including constriction amplitude, latency, duration, velocity, and dilation metrics) were recorded. Between-group comparisons were conducted using parametric or nonparametric tests, as appropriate based on the data distribution.

No significant differences were observed between groups in mean pupil diameter across illumination conditions (all p > 0.05). Dynamic pupillary parameters also did not differ significantly between the study groups. However, both groups demonstrated mild right-to-left asymmetry in static measurements, with a statistically significant interocular difference observed in the VM group under high-photopic conditions (p = 0.001). Dynamic asymmetries were minimal and not clinically meaningful.

Interictal static and dynamic pupillary parameters did not differ significantly between patients with VM and healthy controls. Although minor light-dependent asymmetries were observed, their clinical significance remains uncertain. Further studies incorporating longitudinal designs and multimodal autonomic assessments are warranted to clarify the relationship between autonomic function and VM.