Efficacy of deep brain stimulation of the anterior-medial globus pallidus internus in tic and non-tic related symptomatology in refractory Tourette syndrome

INTRODUCTION: Although refractory Tourette Syndrome (TS) is rare, it poses great challenges in clinical practice. Co-morbid psychiatric symptoms often occur, negatively impacting quality of life. Deep brain stimulation (DBS) targeting different brain structures seems effective for tics, but specific literature regarding response of psychiatric symptoms is more limited. This study aimed to assess the outcome of tics and non-tic related symptomatology in refractory TS treated with antero-medial globus pallidus interna (amGPi) DBS. METHODS: We included all patients with refractory TS (January 2013–August 2020) from the Brain Nerve Centre and Steve Biko Academic Hospital, Pretoria, South Africa, treated with bilateral amGPi DBS; retrospective baseline, early (up to 3 months) post-DBS follow-up assessment data, as well as prospective data from the latest follow-up (mean 37.4 months) were collected using standardised scoring tools and scales. RESULTS: Five patients were identified. Tics decreased by 63,9% (p = 0,002); quality of life improved by 39,8% (p = 0,015); self-injurious behaviour ceased; obsessive–compulsive symptoms resolved in all but one. The number of different chronic medications used more than halved. Transient stimulation-related adverse events occurred in four patients. CONCLUSION: This study contributes to the data of the efficacy of amGPi-targeted DBS in refractory TS, showing improvement in quality of life and both tic- and non-tic-related symptomatology..