Sensory Processing Difficulties and Occupational Therapy Outcomes for Functional Neurological Disorder: A Retrospective Cohort Study.

Background and objectives: Occupational therapy (OT) consensus recommendations and articles outlining a sensory-based OT intervention for functional neurological disorder (FND) have been published. However, limited research has been conducted to examine the efficacy of OT interventions for FND. We performed a retrospective cohort study aimed at independently replicating preliminarily characterized sensory processing difficulties in patients with FND and reporting on clinical outcomes of a sensory-based OT treatment in this population. We hypothesized that (1) a history of functional seizures, anxiety, and/or post-traumatic stress disorder would be associated with increased sensory processing difficulties and (2) the number of OT treatment sessions received would positively relate to clinical improvement.

Methods: Medical records were reviewed for 77 consecutive adults with FND who received outpatient, sensory-based OT care. Data from the Adolescent/Adult Sensory Profile characterized self-reported sensory processing patterns across 4 quadrants (low registration, sensory sensitivity, sensory seeking, and sensory avoidance) in this population. Following univariate screenings, multivariate linear regression analyses were performed to identify neuropsychiatric characteristics associated with discrete sensory processing patterns. Clinical improvement was quantified using an estimated, clinician-determined improvement rating ("improved" vs "not improved"), and relationships between clinical participation, baseline neuropsychiatric factors, and outcomes were investigated.

Results: Patients with FND reported sensory processing patterns with elevated scores in low registration, sensory sensitivity, and sensation avoidance compared with normative values; differences in sensory processing scores were not observed across FND subtypes (i.e., motor, seizure, and speech variants). In linear regression analyses, lifetime history of an anxiety disorder, history of migraine headaches, current cognitive complaints, and a comorbid major neurologic condition independently predicted individual differences in sensory processing scores. Following a sensory-based OT intervention, 62% of individuals with FND were clinician determined as "improved." In a multivariate logistic regression analysis controlling for baseline characteristics associated with improvement ratings, number of treatment sessions positively correlated with clinical improvement.

Discussion: These findings support the presence of sensory processing difficulties in patients with FND and provide Class IV evidence for the efficacy of an outpatient, sensory-based OT intervention in this population. Controlled prospective trials are warranted.