Synkinesis assessment in facial palsy: validation of the Dutch Synkinesis Assessment Questionnaire

The objective of this study is to validate an existing health-related quality of life questionnaire for patients with synkinesis in facial palsy for implementation in the Dutch language and culture. The Synkinesis Assessment Questionnaire was translated into the Dutch language using a forward-backward translation method. A pilot test with the translated questionnaire was performed in 10 patients with facial palsy and 10 normal subjects. Finally, cross-cultural adaption was accomplished at our outpatient clinic for facial palsy. Analyses for internal consistency, test-retest reliability, and construct validity were performed. Sixty-six patients completed the Dutch Synkinesis Assessment Questionnaire and the Dutch Facial Disability Index. Cronbach's alpha, representing internal consistency, was 0.80. Test-retest reliability was 0.53 (Spearman's correlation coefficient, P < 0.01). Correlations with the House-Brackmann score, Sunnybrook score, Facial Disability Index physical function, and social/well-being function were -0.29, 0.20, -0.29, and -0.32, respectively. Correlation with the Sunnybrook synkinesis subscore was 0.50 (Spearman's correlation coefficient). The Dutch Synkinesis Assessment Questionnaire shows good psychometric values and can be implemented in the management of Dutch-speaking patients with facial palsy and synkinesis in the Netherlands. Translation of the instrument into other languages may lead to widespread use, making evaluation, and comparison possible among different providers.