Ethnic and racial characteristics of hemifacial spasm in Hawaii: a clinical cohort analysis

BACKGROUND: Hemifacial spasm (HFS) is frequently reported in Asian populations, yet most prior studies arise from homogeneous ethnic cohorts, limiting our understanding of racial and ethnic disparities as well as potential diagnostic biases. Hawaii's multiethnic community-which includes large Asian and Native Hawaiian / Pacific Islander (NHPI) populations with regionally high rates of hypertension and other cardiovascular risk factors-offers an opportunity to explore disparities in patients with HFS in a unique epidemiological context. METHODS: We retrospectively analyzed data from 60 HFS patients at a single center and compared racial/ethnic proportions to a clinic-wide cohort of 1,019 neurological patients. Expected counts for each racial group in the HFS cohort were computed from the clinic data, and a chi-square goodness-of-fit test assessed differences between observed and expected counts. Additionally, cardiovascular risk factors in our HFS cohort were evaluated against the statewide population of Hawaii to determine whether these comorbidities were disproportionately represented in the HFS cohort. RESULTS: Asians comprised 42% of HFS cases but only 23% of the clinic population, while NHPIs represented 30% of cases and 29% of the clinic population. Whites were underrepresented in HFS cases (22%) compared to the clinic population (32%). The chi-square test showed significant deviation from expected clinic proportions (χ² =13.32, df = 3, p < 0.01), driven primarily by Asian overrepresentation. In the multivariate analysis adjusting for age and sex, Asian patients had 3.17-fold (p = 0.003) higher odds of an HFS diagnosis compared to Whites. CONCLUSION: Within a multiethnic neurologic clinic, Asian patients, particularly Asian women, are significantly overrepresented among those affected by HFS, consistent with prior work. These findings underscore the need for further research into genetic, anatomic, hormonal, or healthcare-related contributors to these disparities, especially in ethnically diverse regions like Hawaii.