Benign essential blepharospasm among residents of Olmsted County, Minnesota, 1976 to 1995: An epidemiologic study

Purpose: To describe the incidence, patient demographics, and response to treatment of benign essential blepharospasm (BEB) in a population-based cohort. Methods. In this epidemiologic study, we searched the Rochester Epidemiology Project database for patients diagnosed with blepharospasm or related disorders between 1976 and 1995. The incident rate denominator was based on a linear interpolation of decennial census data from Olmsted County. The 95% confidence interval for the incidence rate was based on the Poisson distribution. Results: Olmsted County residents (n=295) were diagnosed with blepharospasm or related disorders between 1976 and 1995. Of these, 8 patients met the criteria for BEB. The calculated incidence rate of BEB is 1.2 persons per 100,000 population per year (95% CI, 0.37 to 2.02). At the time of BEB diagnosis, the median patient age was 61.5 years, and symptoms had been present for a median of 24 months. Four patients were men and 4 were women. Four of the 8 patients had Meige syndrome. Three of 4 patients treated with oral medications reported symptomatic improvement. Botulinum toxin injection was offered to all patients, but only 4 elected treatment. All who were treated with botulinum toxin had temporary symptomatic improvement. No patient underwent surgical treatment for BEB. Two patients had resolution of symptoms within the follow-up period. Conclusions: BEB is a rare disorder. In this small, population-based sample, women and men were affected with equal frequency, and half of patients had lower facial dystonia (Meige syndrome). Only half of patients with BEB elected botulinum toxin injections, and none required surgery. Disease remission occurred in 2 of 8 patients.