Processing of Tactile Stimuli in Children with Tourette Syndrome and Attention Deficit Hyperactivity Disorder: An ERP Investigation

Purpose: To investigate and characterize sensory sensitivity in Tourette syndrome (TS) through an evaluation of behaviour, perception and processing of tactile stimuli in children with TS and co-morbid Attention Deficit Hyperactive Disorder (ADHD) compared to typically developing controls (TDC). Methods: Somatosensory evoked P3 potentials were recorded in TS+ADHD and in TDC children aged 6-12 and compared at midline electrodes. Reported sensory sensitivity was measured using the Sensory Profile, while Semmes-Weinstein filaments were used to determine tactile threshold in the same area stimulated during P3 testing. Results: 13 TS+ADHD and 12 TDC were studied. TS+ADHD children reported significantly higher sensory sensitivity (p=.001) and demonstrated a significantly lower tactile threshold (p=.027) than TDC. Furthermore, the amplitude of electrophysiological responses to repetitive tactile stimuli was significantly larger in TS+ADHD (p=.0009). Conclusion: TS+ADHD children are significantly more sensitive to tactile stimulation than controls. ERP differences suggest that central processing alterations could mediate sensory hypersensitivity.MAS