Psychological distress: linking impairment with disability in facial neuromotor disorders

The relationship between facial neuromotor system impairment, disability, and psychological adjustment is not well understood. This study was designed to explore the relation between impairment and disability and the impact of psychological adjustment on the relation for individuals with disorders of the facial neuromotor system. We studied outpatients (n=48; mean age, 49.0; SD=16.3; range, 18 to 84 years) with a facial neuromotor disorder and acute or chronic facial paralysis. Measures of impairment (Facial Motion Assay, House-Brackmann scale, and Facial Grading System), disability (Facial Disability Index, physical and social well-being subscales), and psychological adjustment (Beck Anxiety Inventory, Beck Depression Inventory) were administered. Bivariate correlations between impairment and disability measures indicated impairment was positively correlated with physical and social disability (r=0.44, p < 0.01; r=0.39, p < 0.05, respectively). Stepwise regression analysis to predict disability indicated physical disability was predicted by impairment and the interaction of impairment and psychological distress (R2=0.425; F=12.57; df=2, 34; p=0.002). Psychological distress, and not impairment and the interaction of impairment and distress, was the single predictor of social disability (R2=0.274; F=13.23; df=1, 35; p=0.001). Psychological distress was a moderator of the relation between impairment and physical disability and a mediator of the relation between impairment and social disability for individuals with facial neuromotor disorders. Assessment and interventions targeted for psychological distress in addition to interventions targeted for impairments appear warranted to effectively reduce the disability associated with facial neuromotor disorders.