Sensory Processing Difficulties in Functional Neurological Disorder: A Possible Predisposing Vulnerability?

Background: Functional neurological disorder (FND) is a prevalent neuropsychiatric condition characterized by sensorimotor difficulties. Patients with FND at times report that sensory experiences trigger and/or exacerbate their symptoms. Sensory processing difficulties are also commonly reported in other psychiatric disorders frequently comorbid in FND, suggesting that contextualizing sensory profiles in FND within a biopsychosocial model may be clinically relevant. Objective: To address this literature gap, we conducted a retrospective cohort study to examine sensory processing patterns and their relationship to other neuropsychiatric characteristics in patients with FND. Methods: A retrospective chart review design was used to investigate sensory processing patterns, established with the AdolescentlAdult Sensory Profile self-report questionnaire, in 44 patients with FND. Univariate analyses of cross-sectional screening tests followed by multivariate linear regression analyses were performed to identify clinical factors associated with sensory processing scores in the FND cohort. Results: Compared to normative data, most patients with FND reported sensory processing tendencies toward low registration, sensory sensitivity, and sensation avoiding. In multivariate regression analyses, the presence of a lifetime anxiety disorder independently predicted elevated low registration scores, while female gender and number of current medications independently predicted increased sensory sensitivity scores. In uncorrected univariate analyses only, individuals with psychogenic nonepileptic seizures were more likely to report increased sensory sensitivity and elevated low registration. Conclusion: These preliminary findings support sensory processing difficulties in some patients with FND. Prospective and large sample size studies are needed to investigate relationships between sensory processing profiles and neuropsychiatric comorbidities, FND sub-types, and treatment outcomes.