Characteristics of Self-Motion Sensation after Major Earthquake: Internet Survey

Abstract Background It has been reported that after experiencing a major earthquake, one may feel as though their body is swaying, even when they are not actually moving. A magnitude 7.6 earthquake struck the Noto Peninsula on New Year’s Day 2024. To investigate the prognosis of self-motion sensations following an earthquake, we conducted an Internet survey of local residents in the area surrounding the epicenter. Methods A cross-sectional Internet monitoring survey was conducted two months after the earthquake and 1,000 responses were received. Of these, 968 were included in the final analysis. Logistic regression analysis was used to examine the association of age, sex, residence, and personal characteristics with the incidence of self-motion sensation after an earthquake, degree of disturbance in daily life, and persistence of symptoms, based on participants' responses to a questionnaire. Results Of the 968 participants, 416 (43.0%) experienced a brief self-motion sensation for the first time after the earthquake. More than half the participants were anxious or scared about this sensation. A total of 18.5% of participants experiencing self-motion sensations reported that these sensations were disrupting their daily lives. This disruption was associated with being younger, having a history of dizziness treatment, and experiencing anxiety. More than half of the self-motion sensations resolved within two weeks; however, 24.5% persisted after two months. Proximity to the epicenter and anxiety were associated with prolonged self-motion sensations. Conclusions Self-motion sensations are common after a major earthquake and usually resolve spontaneously. However, the findings show that quarter of the participants with self-motion sensation experienced prolongation of symptoms and disrupted the daily lives of nearly 20%. Additionally, having anxiety was associated with a worse prognosis. Focused attention is required for individuals with characteristics associated with vulnerability to self-motion sensations.