Prefrontal Cortical Stimulation in Tourette Disorder: Proof-of-concept Clinical and Neuroimaging Study

Background The benefits of neurosurgery in Tourette Syndrome (TS) are still incompletely understood. Prefrontal cortical electrical stimulation offers a less invasive alternative to deep brain stimulation. ObjectiveMethodsTo perform a pilot assessment on safety and efficacy of prefrontal cortical bilateral electrical stimulation in TS using clinical and brain metabolic assessments. Four adult TS patients underwent tic assessment using the Yale Global Tic Severity Scale and the Rush Video Rating Scale at baseline and 1, 3, 6, and 12-months after implant; whereas FDG-PET scans were acquired at baseline and after 6 and 12 months. ResultsConclusionTic clinical scores were improved at 6 months after implant, meanwhile they showed a tendency to re-emerge at the 12-month follow-up. There was a correlation between FDG-PET and tics, mainly consisting in a reduction of baseline brain hypermetabolism, which paralleled tic score reduction. Epidural stimulation in TS is safe and yields a modulation of tics, paralleled by FDG-PET metabolic modulation.