Distinguishing Tics and Functional Tics Using Clinical Neurophysiological Techniques

Study Description:

The purpose of the protocol is to explore the physiological difference between patients with tics and functional tics.

Objectives:

Primary Objective: To determine if there are differences in cortical excitability before tics in patients with tics compared to functional tics.

Secondary Objectives: N.A.

Exploratory Objectives: To determine if there are differences in cortical and subcortical excitability before tics in patients with tics compared to functional tics.

Endpoints:

Primary Endpoint: This is a hypothesis-driven study. The primary outcome measure is the beta power of EEG signal before the tics at

the electrode over the vertex.

Secondary Endpoints: N.A.

Other exploratory outcome measures include EEG signal power across different frequency bands and Bereitschaftspotential at various electrodes with different movements. Blink reflex and pre-pulse inhibition will also be measured in patients with tics and functional tics and healthy controls under different conditions.

• INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

• Capacity to provide informed consent (self-consent)
• Stated willingness to comply with all study procedures and availability for the duration of the study
• Male or female, aged 18-80
• Agreement to adhere to Lifestyle Considerations prior to and during the physiological testing visit.

Inclusion criteria

for patients with functional tics or tics

• Diagnosed with functional motor tics or motor tics

Inclusion criteria

for healthy controls

• Have no neurological or psychiatric disorders established by history and physical/neurological examination

Exclusion criteria

• Self-reported consumption of >14 alcoholic drinks/week* for a man and >7 alcoholic drinks/week for a woman
• Use of prescription drugs and other illicit drugs that may suppress tics such as dopamine blocking agents and antipsychotics during a certain time period prior to the

neurophysiological testing session.**

• Clinically significant abnormal movements on neurological examination except for tics.
• Contraindications to EEG or EMG procedures, including skin lesions at electrode sites or hypersensitivity to electrode materials.
• History of or current brain tumor, stroke, head trauma with loss of consciousness.
• Epilepsy or seizures in the past 12 months.
• Have a Baclofen pump, or have neurostimulators for pain.
• Pregnant women
• Self-reported current major depression or Beck Depression Inventory II (BDI-II) score >19, Generalized Anxiety Disorder 7-item scale (GAD-7) score > 9, or any major current psychiatric illness.
• Presence of any metal in the eye or skull area such as a brain stimulator, shrapnel, surgical metal, clips in the brain, cochlear implants, metal fragments in the eye.
• Presence of pacemaker, intracardiac lines, implanted pumps or stimulators.
• Unable to comply with the requirements of the study procedures.
• Vocal tics only tested with Modified Rush Video-Based Tic Rating Scale.
• Low Premonitory Urge for Tics Scale (PUTS) score < 9 (maximum 36) with low willingness for tics (patient groups only, not applicable in healthy volunteers).

• Note: 1 standard alcoholic drink is 0.6 ounce (14 grams) of pure alcohol.

• Note: The certain time period depends on different drugs used. Five half-lives will be selected. The drug is considered effectively eliminated from the body after this time period because the concentration of the drug reaches around 3% of the orininal concentration.