TICS: Transcranial Magnetic Stimulation for Intervening in Children With Tourette's Syndrome (CIHR)

Tourette's Syndrome (TS) is characterized by repetitive movements and vocalizations called tics. Due to the suffering caused by TS, children and adolescents often require treatment for their tics. The investigators' research focuses on developing novel repetitive transcranial magnetic stimulation (rTMS) interventions for child and adolescent neuropsychiatric disorders. In this project, the investigators will determine the effect of pairing 3 weeks of rTMS and HRT on tic severity and plasticity as indexed by supplementary motor area (SMA) y-aminobutyric acid (GABA) concentration and functional connectivity of the SMA to the primary motor cortex (M1) in children and adolescents with TS.

Children (N = 50, 6-18 years) with TS will be randomized to either a (1) rTMS+HRT arm, or (2) sham rTMS+HRT. Outcome measures will examine tic severity (primary), brain chemistry and function (secondary) at baseline and then at week 7. The investigators' proposed aims are:

(Aim 1) To determine the effect of paired rTMS and HRT on tic severity as measured by the Yale Global Tic Severity Scale (YGTSS) by comparing it to sham rTMS + HRT.

1-1: The investigators hypothesize that tic severity will decrease from baseline to post-treatment.

1-2: The investigators also hypothesize that the reduction in tic severity will be greater in the paired treatment group (rTMS+HRT \> Sham rTMS+HRT).

(Aim 2) To determine the effect of paired rTMS and HRT on brain plasticity compared to sham rTMS + HRT.

2-1: The investigators hypothesize that patients treated with the paired rTMS and HRT will have a greater increase in GABA concentration comparted to sham and HRT.

2-2: The investigators also hypothesize that functional connectivity between the SMA and M1 will be greater with paired treatment (rTMS+HRT \> Sham rTMS+HRT).

Tourette's Syndrome (TS) is characterized by repetitive movements and vocalizations called tics. Due to the suffering caused by TS, children and adolescents often require treatment for their tics. Tic severity predicts poor outcomes across physical, psychological, and cognitive domains in youth. Current treatments for TS remain limited in scope and efficacy. Atypical antipsychotics are often used and for many patients have an unacceptable side effect burden. Behavioral treatments, like habit reversal therapy (HRT), show promise and are safe, but are predicated on a certain level of brain maturation to execute.

The investigators' research focuses on developing novel repetitive transcranial magnetic stimulation (rTMS) interventions for child and adolescent neuropsychiatric disorders. Plasticity, precision, and pairing are key considerations in this process. In this project, the investigators will determine the effect of pairing 3 weeks of rTMS and HRT on tic severity and plasticity as indexed by supplementary motor area (SMA) y-aminobutyric acid (GABA) concentration and functional connectivity of the SMA to the primary motor cortex (M1) in children and adolescents with TS. The investigators will use functional magnetic resonance imaging (fMRI) and robot controlled rTMS to precisely target the SMA. The investigators believe this pairing will provide improved relief by inducing plasticity to retrain the brain to be better at suppressing tics at an earlier age than usually expected.

Children (N = 50, 6-18 years) with TS will be randomized to either a (1) rTMS+HRT arm, or (2) sham rTMS+HRT. Outcome measures will examine tic severity (primary), brain chemistry and function (secondary) at baseline and then at week 7. The investigators' proposed aims are:

(Aim 1) To determine the effect of paired rTMS and HRT on tic severity as measured by the Yale Global Tic Severity Scale (YGTSS) by comparing it to sham rTMS + HRT.

1-1: The investigators hypothesize that tic severity will decrease from baseline to post-treatment.

1-2: The investigators also hypothesize that the reduction in tic severity will be greater in the paired treatment group (rTMS+HRT \> Sham rTMS+HRT).

(Aim 2) To determine the effect of paired rTMS and HRT on brain plasticity compared to sham rTMS + HRT.

2-1: The investigators hypothesize that patients treated with the paired rTMS and HRT will have a greater increase in GABA concentration comparted to sham and HRT.

2-2: The investigators also hypothesize that functional connectivity between the SMA and M1 will be greater with paired treatment (rTMS+HRT \> Sham rTMS+HRT).

Eligibility Criteria:
Inclusion Criteria:

1. Diagnosis of Tourette's syndrome
2. IQ greater than 80
3. English fluency (to enable assent and consent).

Exclusion Criteria:

1. Diagnosis of mania or schizophrenia
2. Impediments to TMS or MRI.