469 Electroencephalographic Correlate of Sensory Over-Responsivity in Adults with Chronic Tic Disorders

Abstract

OBJECTIVES/GOALS: To identify an electroencephalographic (EEG) signature of SOR in adults with TS METHODS/STUDY POPULATION: We will recruit 60 adults with CTD and 60 sex- and age-matched healthy controls to complete scales assessing severity of SOR (Sensory Gating Inventory, SGI), tics, and psychiatric symptoms. Subjects will then be monitored on dense-array scalp EEG during sequential auditory and tactile sensory gating paradigms, as such paradigms have been shown to correlate with self-report measures of SOR in other populations. Single-trial EEG data will be segmented into 100-ms epochs and spectrally deconvoluted into standard frequency bands (delta, theta, alpha, beta, gamma) for pre-defined regions of interest. We will conduct between-group contrasts (Wilcoxon rank-sum) of band-specific sensory gating indices and within-group correlations (Spearman rank correlations) between sensory gating indices and SGI scores. RESULTS/ANTICIPATED RESULTS: We hypothesize that, relative to controls, adults with CTD exhibit impaired sensory gating and that extent of impairment correlates with severity of SOR. 14 adults with CTD (9 men, 5 women) and 16 controls (10 men, 6 women) have completed the protocol to date. Within this sample, adults with CTD showed significantly reduced sensory gating compared to controls in frontal (CTD median 0.12 dB (interquartile range -0.15–0.70 dB); control -0.37 dB (-0.80–-0.13 dB); p = 0.01) and parietal (CTD 0.17 dB (-0.08–0.50 dB); control -0.20 dB (-0.43–0.10 dB); p = 0.01) gamma band during the 100-200 ms epoch in the tactile paradigm. No significant between-group differences were evident for the auditory paradigm. Among adults with CTD, multiple sensory gating indices significantly correlated with SGI scores. Enrollment continues. DISCUSSION/SIGNIFICANCE: Results aim to clarify the extent of sensory gating impairment in TS and identify a clinical correlate of neurophysiologic dysfunction in the disorder. Such knowledge has direct implications for identification of candidate neurophysiologic biomarkers, an express goal of the National Institutes of Health.