Sensitivity and specificity of a self‐administered questionnaire for familial screening of adult‐onset dystonia

We developed a self‐administered questionnaire for screening the most common adult‐onset dystonias. It was tested in 90 first‐degree relatives of 22 adult‐onset dystonia patients, yielding 79% sensitivity and 94% specificity. Simulation of a case‐finding procedure based on serial application of the questionnaire and clinical examination of both subjects screening positive and subjects screening negative who had < 8 years of schooling increased sensitivity to 95% and specificity to 100%. This questionnaire may be an important screening resource for familial aggregation studies to be used in the context of a complex case‐finding procedure. © 2005 Movement Disorder Society