Brain and reflex testing to distinguish organic and functional tics

* 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.