Deep brain stimulation of anteromedial globus pallidus internus improved OCD rather than tics in a Gilles de la Tourette syndrome patient.

A 32-year-old gentleman with refractory Gilles de la Tourette syndrome went on a DBS procedure on anteromedial globus pallidus internus. At the most suitable adjustment, the OCD component of his disease improved almost completely while his tics remained unchanged which was in contrast with other previous studies. Moreover, variations in symptoms were seen in response to different adjustments. We discuss that these variations and fluctuations in the therapeutic outcomes may be due to differences in physiological conditions of tic- or OCD-specified pathways and areas including distinct stimulation threshold and occurrence of neuroplasticity in neural circuits which may determine the responsiveness of each pathway or circuit to a specific stimulus. At last, we suggest that pathways and circuits should be targeted for DBS rather than single components; as these components may be involved in multiple pathways, related to different pathophysiological states.