Sensory processing profiles and their association with tic severity in children with tic disorders: a cross-sectional...

Sensory symptoms have been increasingly recognized as core characteristics of tic disorders (TD). This study aimed to systematically investigate the core features of sensory processing abnormalities in Chinese children with tic disorders, analyze their association with tic severity, and explore potential subtypes based on sensory profiles.

This cross-sectional study recruited 151 children diagnosed with TD (encompassing Tourette syndrome, chronic motor tic disorders, and provisional tic disorders) along with 100 age-matched healthy controls (HC). Sensory processing characteristics were assessed using the Short Sensory Profile, and tic severity was evaluated with the Yale Global Tic Severity Scale. Principal component analysis (PCA) and latent profile analysis (LPA) were employed to explore sensory subtypes. Correlation analyses and regression models were used to examine sensory-symptom relationships.

Children with TD showed significantly lower total SSP scores than HCs (P < 0.001), with deficits primarily in "under-responsive/sensation seeking", "auditory filtering" and "low energy/weakness". PCA extracted two core dimensions: "sensory dysfunction" and "sensory hypersensitivity". A significant positive graded relationship was found between the degree of sensory abnormality and tic severity (P for trend = 0.025). The "under-responsive/ sensation seeking" dimension was an independent predictor of tic severity (β = -0.164, P = 0.044). LPA identified two subtypes: a "relatively typical sensory processing" subtype (88.7%) and a "sensory over-responsivity" subtype (11.3%). However, no significant difference in tic severity was found between these subtypes.

Sensory processing abnormalities, particularly generalized sensory modulation dysfunction, are prevalent across TD subtypes and are closely associated with tic severity. Sensory under-responsivity represents a core risk dimension, while the unique "sensory over-responsivity" subtype may be relatively independent of tic severity. This study provides important evidence for sensory-based subtyping of TD and for developing individualized interventions targeting sensory symptoms.