Biofeedback of Activity in the Supplementary Motor Area to Reduce Tics in Tourette Syndrome

Lay Summary

Providing Real-Time fMRI Biofeedback to Tourette’s Syndrome Patients May Reduce Symptoms

Current treatments for mental disorders are limited.  Many individuals do not respond well to the available drugs or behavioral therapies.  In addition, those who do respond well to drugs often experience unpleasant side effects.  In more severe cases, treatments involving surgery or methods that directly stimulate regions of the brain may be used, but the risks and long-term consequences of these interventions are not well understood.  We will investigate a novel form of treatment for mental illness involving minimal risks and side effects, known as biofeedback.

Participants in biofeedback studies are provided with a training signal reflecting some unconscious internal variable that they must learn to control.  For our study, this training signal will indicate the level of neural activity in a specific part of their brain.  In order to monitor activity in that brain area, we will be taking pictures of the subject’s brain activity using functional magnetic resonance imaging.  We will process those images immediately as they are collected to provide up-to-date information to the subject regarding activity in the brain area of interest.  This information will then enable subjects to learn control over activity in that brain area.

This biofeedback approach will be tested as a potential treatment of Tourette Syndrome (TS).  TS is a disorder affecting many children and adolescents that in some cases can persist into adulthood.  This disorder is characterized by repetitive, unwanted movements, or tics, that can be socially awkward, exhausting, and even self-injurious.  Although drugs are available to treat these tics, many individuals either do not respond to the drugs or find their side effects unacceptable.

Our hypothesis is that the tics of TS are caused by an excess of activity in a region of the brain that plans and facilitates movement, called the supplementary motor area (SMA).  This hypothesis is based on the following facts: (1) electrical stimulation of this brain region causes tics (2) this area has been shown to be active prior to tic movements in TS patients and (3) inhibition of this area has been reported to decrease tics in TS patients.  Therefore, we will train TS patients to control neural activity in this brain area.  We predict that as they learn to control the activity in this brain area, their tic symptoms will improve.

In addition to the potential clinical benefits of this study for Tourette Syndrome, the development of biofeedback of fMRI data as a clinical tool has potential implications for a wide range of mental disorders.  Biofeedback of the neural activity level in a specific brain area may enable patients with disrupted brain activity patterns to normalize their brain function.  This possibility, considered together with the fact that biofeedback is non-invasive and free of side-effects, makes it a promising new technology for the field of mental health.  The proposed study would represent one of the first investigations regarding the clinical utility of this novel form of biofeedback.

Abstract

Biofeedback of Activity in the Supplementary Motor Area to Reduce Tics in Tourette Syndrome

Despite a great deal of pharmacological research, the drugs that have been developed to treat mental disorders have limited efficacy and undesirable side effects. Other treatment options, such as surgery, electroshock therapy, and repetitive transcranial magnetic stimulation (rTMS), are risky and aversive to many patients. The proposed study will investigate the utility of a novel treatment approach involving biofeedback of functional magnetic resonance imaging (fMRI) data. Biofeedback is a noninvasive approach, in which patients are provided with a training signal reflecting some unconscious internal variable that they must learn to control. Methods for analyzing fMRI data as it is collected (with delays of only a couple of seconds) have recently been developed. These methods, known as real-time fMRI, have made it possible to track how activity in a specific brain area is changing during a scan. We are investigating whether biofeedback of such information can enable subjects to learn control over the brain area of interest, and to thereby develop healthier patterns of brain function.

This proposal investigates whether biofeedback of real-time fMRI data can be an effective treatment for patients with Tourette Syndrome (TS). TS is a disorder affecting many children and adolescents that in some cases can persist into adulthood. This disorder is characterized by repetitive, unwanted movements, or tics, that can be socially awkward, exhausting, and even self-injurious. For many individuals, current pharmacological and behavioural treatments are ineffective, and the alternative treatments currently available, including deep brain stimulation and rTMS, are unacceptably disruptive and risky.

We hypothesize that the tics experience by patients with TS are caused by aberrant activity arising in their supplementary motor area (SMA). This hypothesis is based on the following data: (1) electrical stimulation of the SMA of humans causes tic-like symptoms (2) functional imaging studies of patients show this area is abnormally active prior to tic movements and (3) rTMS studies have reported decreased tic symptoms after inhibitory stimulation of this brain area in TS patients. Therefore, we propose to train patients to control neural activity in their SMA and hypothesize that an ability to control activity in that brain area will translate into a reduction in tic symptoms.

In addition to the potential clinical benefits of this study for Tourette Syndrome, the development of biofeedback of real-time fMRI data as a clinical tool has potential implications for a wide range of mental disorders. Biofeedback of real-time fMRI data may enable patients with disrupted brain activity patterns to normalize their brain function. This possibility, considered together with the fact that biofeedback is relatively safe and free of side-effects, makes biofeedback of real-time fMRI data a promising new technology for the field of mental health. The proposed study would represent one of the first investigations regarding the clinical utility of this novel form of treatment.