Brain and reflex testing to distinguish organic and functional tics
Distinguishing Tics and Functional Tics Using Clinical Neurophysiological Techniques
National Institutes of Health Clinical Center (CC) · NCT07137442
This test uses EEG, EMG, blink reflex, and pre-pulse inhibition recordings to see if brain and reflex signals can tell apart adults with organic tics, adults with functional tics, and people without tics.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 75 (estimated) |
| Ages | 18 Years to 80 Years |
| Sex | All |
| Sponsor | National Institutes of Health Clinical Center (CC) (nih) |
| Locations | 1 site (Bethesda, Maryland) |
| Trial ID | NCT07137442 on ClinicalTrials.gov |
What this trial studies
Adults with motor tics, adults with functional motor tics, and healthy controls attend a single 4-hour clinic visit (which can be split over 1–2 days) for physiological testing. Participants wear EEG and EMG sensors while clinicians record brain activity around tic events, focusing on beta power at the vertex and Bereitschaftspotential signals. Additional measures include blink reflex testing and pre-pulse inhibition to probe subcortical excitability. The primary aim is to see if cortical excitability before tics differs between groups, with exploratory analysis of other frequency bands and reflex measures.
Who should consider this trial
Good fit: Adults aged 18–80 with a diagnosis of motor tics (organic) or functional motor tics, and healthy adults with no neurological or psychiatric disorders, are appropriate candidates.
Not a fit: People under 18, those unable to give informed consent, and those currently using tic-suppressing antipsychotics or with heavy alcohol or illicit drug use are not eligible and unlikely to benefit from participation.
Why it matters
Potential benefit: If successful, the tests could help doctors more accurately tell whether a patient's tics are organic or functional, leading to more appropriate treatment plans.
How similar studies have performed: Prior studies using EEG readiness potentials, blink reflexes, and pre-pulse inhibition have shown differences between organic and functional movement disorders, but applying this combined cortical and subcortical testing specifically to tics is still an emerging approach.
Eligibility criteria
Show full inclusion / exclusion criteria
* 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.
Where this trial is running
Bethesda, Maryland
- National Institutes of Health Clinical Center — Bethesda, Maryland, United States (RECRUITING)
Study contacts
- Principal investigator: Debra J Ehrlich, M.D. — National Institute of Neurological Disorders and Stroke (NINDS)
- Study coordinator: Zhen Ni, Ph.D.
- Email: zhen.ni@nih.gov
- Phone: (301) 435-2175
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions: Tics, Functional Tics, Functional tics, EEG, Blink Reflex, Pre-pulse inhibition