Neural Correlates of Sensory Phenomena in Tourette Syndrome
The primary aim of this study is to identify neural correlates of sensory phenomena in adults with Tourette syndrome (TS). Adult patients with TS will be recruited 1) to complete a standardized clinical symptom assessment battery and 2) to undergo monitoring with video-electroencephalogram (EEG) during tactile and auditory tasks, as well as in a resting state.
- Tourette Syndrome
- Sensory Disorders
- Eligible Ages
- Over 18 Years
- Eligible Genders
- Accepts Healthy Volunteers
- Diagnosis of Tourette syndrome
- Age greater than or equal to 18 years
- Prior diagnosis of autism spectrum disorder, developmental delay, cerebral palsy, other significant neurologic disease, schizophrenia, or psychotic disorders
- Previously diagnosed hearing or tactile impairment
- Current use of benzodiazepines (e.g. Clonazepam, Diazepam, Alprazolam) or anti-seizure medications (e.g. Topiramate, Lamotrigine)
- Study Type
- Observational Model
- Time Perspective
|Tourette Syndrome||Adults (>18 years of age) with diagnosis of Tourette syndrome||
|Healthy Control||Adults who are generally healthy with no known neurologic or psychiatric diagnoses||
- Vanderbilt University Medical Center
Study ContactDavid A Isaacs, MD
Tourette syndrome (TS) is a neurodevelopmental disorder affecting 1% of school-aged children; one-third of patients suffer persistent tics into adulthood. Diagnostic criteria rely solely on motor symptoms, but sensory phenomena are a nearly universal feature, manifesting as 1) premonitory urges (PUs) and 2) sensory hypersensitivity. 1) Ninety percent of patients perceive unpleasant premonitory bodily urges preceding tic expression, and 60% find these more distressing than tics themselves. As PUs and tics are clinically paired, one would expect tight symptom severity correlation; however, published results are conflicting. Imaging studies reveal the likely role of a widespread sensory processing network in PU formation, but much ambiguity surrounds the precise neural substrates of PUs. 2) In addition to PUs, 80% of TS patients report heightened awareness of internal and external stimuli. Scant research has been devoted to this aspect of TS, but one small series found this sensory hypersensitivity to be independent of both PU and tic severity, delineating it as a distinct facet of the syndrome. Despite their ubiquity and detrimental impact on quality of life, sensory phenomena in TS remain poorly understood: the clinical relationship with tics is unclear, the pathophysiologic mechanisms are imprecisely characterized, and the treatment is non-existent. Network oscillations, captured in real-time with EEG, are a promising means of addressing this crucial knowledge gap.
Part 1. Clinical Variables and Scales - Adult TS patients will be recruited to complete a battery of validated clinical scales, providing a comprehensive phenotype. The scales include the following: Yale Global Tic Severity Scale (YGTSS); Dimensional Obsessive-Compulsive Scale (DOCS); Adult ADHD Self-Report Screening Scale for DSM-V; Generalized Anxiety Disorder 7 (GAD-7); Patient Health Questionnaire 9 (PHQ-9); Premonitory Urge to Tic Scale (PUTS); Sensory Gating Inventory (SGI); Sensory Perception Quotient (SPQ); and GTS-Quality of Life (GTS-QOL) Rating Scale. Patients with previously diagnosed autism spectrum disorder, developmental delay, cerebral palsy, other significant neurologic disease, schizophrenia, or psychotic disorders will be excluded, in order to lessen potentially confounding factors. Patients with obsessive-compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), anxiety, and/or depression will be permitted, given that these diagnoses are widely prevalent in the adult TS population. Age-matched, healthy-controls (HCs) will be recruited to complete the mood and sensory instruments. All study procedures will be completed during a single testing session. Medical and neurologic history, family history, substance use history, developmental history, and current and past psychotropic pharmacotherapies, will be reviewed.
Part 2. EEG Testing - Each participant will undergo a single-session EEG paradigm consisting of somatosensory and auditory event-related potentials (ERP), as well as a resting state condition. The somatosensory stimulus consists of a non-painful stimulus to the arm, and the auditory stimulus consists of a non-painful sound delivered through headphones. The entire recording session will take approximately 1-1.5 hours. Participants will be video-recorded, to allow for subsequent identification of tics.