A study of sensory dysregulation in children with tic disorders.

Disrupted somatosensory processing characterized by over- or under- responsiveness to environmental stimuli plays an important, yet often overlooked, role in typical development and is aberrant in various neurodevelopmental disorders. These dysfunctional somatosensory processes have been conceptualized as an entity termed somatosensory dysregulation (SMD). Since Tourette syndrome (TS) is a prototypical example of developmental psychopathological disorder, we hypothesised that SMD would be a feature found in children suffering from the disorder. Ninety-two subjects representing consecutive admissions to a tertiary paediatric Tourette syndrome clinic were admitted to the study. Comorbid conditions included ADHD, depression, anxiety disorder, and OCD. For purposes of the study, patients completed a battery of self-, caregiver-, and clinician-rated psychological instruments measuring TS core symptoms and comorbidities and quality of life. Sensory modulation was measured by self-report and by objective measures such as stimulation with Von Frey filaments. Almost 50% of the cohort had no SMD. Of the remainder, 14 (15%) had suspected SMD and 32 (34.8%) had SMD. SMD was significantly more common and severe when there were comorbidities. The presence of SMD was associated with more severe impairments in quality of life and less participation in daily activities. The SMD, as measured by subjective measures but not by objective, is probably more associated with central processing rather than peripheral perception.