tic disorders Treatment Tic Disorders blog Tics at WUSTL

Can median nerve stimulation reduce tics?

A fascinating publication from the University of Nottingham describes a non-invasive method that may reduce tics. The idea is that rhythmic input to a brain region can entrain that region to fire in synchrony with the input, and some rhythmic firing patterns seem to inhibit movement. The stimulation was delivered by generating a small electrical current to the skin over a nerve in the wrist (the median nerve). The current is dialed down to just barely enough to make the thumb twitch.

The authors tested this new idea in two ways. First, they showed that brain activity in an area of the brain corresponding to sensation and movement could be synchronized with the electrical pulses at the wrist. A control condition with the pulses delivered differently did not produce the same effect.

Second, 19 volunteers with TS engaged in a 4-minute-long study in which 2 of the minutes included median nerve stimulation (MNS) and 2 minutes did not. The order of stimulation vs. no stimulation varied across participants. Six of the 19 people found the stimulation uncomfortable. The participants were video recorded during the 4 minutes, and a tic doctor who didn’t know when the stimulation was on or off counted tics and rated their severity for each minute of the 4 minutes. Different people had different results, but on average, tic frequency and severity decreased (by about 30%; see Figure 5 in the paper referenced below). A few participants reported dramatic benefit during stimulation (see video S1 in the paper referenced below). Their experience was shared in the news, which of course has generated substantial interest from the public.

The Nottingham experiment is very clever, and provides a potential new treatment. However, important questions remain. Can the improvement be made to last more than a few minutes? How many people improve with MNS? Can we predict who will benefit and who won’t? Does the stimulation have to be delivered they way they did it to produce clinical benefit? Can the stimulation be provided, say, for 5 seconds every minute, or does it need to be continuous? We need to know some of these answers before we know how useful MNS may be in real life.

I have been working with the researchers from Nottingham, who are continuing with this line of research, and we are starting a follow-up study here at Washington University.

It’s worth remembering that MNS is far from the only option for treatment. Several effective treatments for tics are already available, and we are also testing new medications and behavior therapies.

UPDATE June, 2021: We are enrolling! Click here to find out how to volunteer.

Reference

Morera Maiquez B et al.: Entraining Movement-Related Brain Oscillations to Suppress Tics in Tourette Syndrome. Current Biology 2020; DOI 10.1016/j.cub.2020.04.044.

18 Comments

  1. Hi what are your effective treatments for tics? I’m all ears. Please tell me so I may ask my neurologist.

  2. We have prepared a detailed plan for a first study in our lab, to confirm the results from our Nottingham colleagues, to see whether clinical benefit from MNS lasts after you turn it off, and to test for the first time whether placebo stimulation works just as well as “real” stimulation (https://osf.io/mtbzf/). We have also applied to the Foundation for Barnes-Jewish Hospital and the Washington University Institute of Clinical and Translational Sciences for initial funding to carry out this work. (We’ll hear back from them in November.) The next step, which we are working on now, is applying for ethics committee approval to conduct this study. Once that is granted we can begin this research (and will add the appropriate information to this page). Please note, we believe the work we propose to do is the next crucial step towards turning MNS into a useful treatment, but MNS is not yet at the stage to send people home with a treatment device.

    In the meantime, there are proven psychological and medication treatment options for TS (https://tics.wustl.edu/treatment/treating-tics-an-overview/), and children who are eligible may be interested in a study of a new class of medication for TS (https://tics.wustl.edu/new-treatment-study-for-children-with-tourette-syndrome/).

  3. Dr. Black. My daughter is 17 with Tourettes and would like to participate in the study. Could you kindly reach out to us when you begin searching for volunteers? Are you the only institution that is conducting a study in the US?

    Thank you!

  4. Dr. Black, is there a chance to follow the study and its result for non-scientists?
    I’m a life-long TS sufferer and reading news like this brings some hope, first in decades I really see something promising so can’t help myself but googling news on this matter every couple weeks. Unfortunately, every time I check up on that I see nothing but same links to the news from June – July.

  5. Late news, but I wanted to report that the Foundation for Barnes-Jewish Hospital and the Washington University Institute of Clinical and Translational Sciences selected our proposal for initial funding to carry out the testing of MNS as described above (original post and Sept. 3, 2020, update). We are grateful to those who made this possible financially: donors to FBJH and WUSTL, and the U.S. NIH (NCATS) Clinical and Translational Science Awards Program Grant (UL1 TR002345). Funding will begin March 1, 2021.

    1. Dear Dr. Black, please update us on this. Did the funding go well? any target dates on when the study will conclude? I appreciate the work you do and Have been following all of your updates regularly.

      Thank you.

    2. Have you begun with the Clinical Trials for MNS? Can you give us any updates on this trial?

  6. UPDATE
    Thank you to all of you who have replied to this post volunteering to participate. We didn’t post most of those replies because we want to protect your privacy. We noted your email addresses and will be in touch with you personally if we have not been already.

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