An internet–based survey on the definition of Shibire

Shibire, a common Japanese term for abnormal somatosensory experience, often coexists with pain. Its ambiguity impedes clinical communication and research. We investigated the interpersonal differences in Shibire’s definitions and prevalence in a Japanese cohort. A nationwide internet–based survey of 1,000 Japanese adults was conducted. Participants defined Shibire by endorsing one or more of three components: Positive sensory symptoms (PSS), Negative sensory symptoms (NSS), and Perceived motor weakness (PMW). We also assessed the prevalence and intensity of Shibire and coexisting pain using a Numerical Rating Scale (NRS), and characterized coexisting pain using the Short–Form McGill Pain Questionnaire 2 (SF–MPQ–2). The point prevalence of Shibire was 22.5%. Among the 581 valid respondents, the most frequently endorsed component for the definition of Shibire was PSS (85.7%), followed by PMW (64.5%), and NSS (56.5%). While Shibire could be defined by a single component or a combination of components, the largest subgroup (37.9%) defined it as a combination of all three components. The overall intensity of Shibire correlated most strongly with PSS intensity (ρ = 0.79), and multiple regression analysis identified PSS as the factor most strongly associated with Shibire intensity (β = 0.64). The NSS component correlated with the SF–MPQ–2 "numbness" descriptor. Individuals perceive Shibire as a complex, multicomponent experience or a single sensation. Shibire is a multifaceted term that covers the positive sensory, negative sensory, and motor domains. Its high prevalence is a significant public health concern. To ensure accurate diagnosis and research, clinicians should deconstruct the complaint of Shibire by asking patients to specify its components.