title: High-frequency pallidal stimulation eliminates tic-related neuronal activity in a nonhuman primate model of Tourette syndrome.
abstract: High-frequency deep brain stimulation targeting the output nucleus of the basal ganglia, the globus pallidus internus, has been suggested as a treatment modality for intractable Tourette syndrome and basal-ganglia-mediated motor tics. Recent studies on the modeling of motor tics induced by focal injections of bicuculline to the striatum, a putative model of Tourette syndrome, have shown that tics induce a widespread modulation within both segments of the globus pallidus. The purpose of this study was to investigate, using the bicuculline-induced Tourette syndrome model, whether and how high-frequency deep brain stimulation targeted to the globus pallidus internus could modulate tic-related activity in the pallidum. The perievent rate changes coinciding with tic expression under the on-stimulation and off-stimulation conditions were examined to determine the effect of high-frequency stimulation on pallidal activity. The results showed that the stimulation blocked tic-related phasic changes in the firing pattern of pallidal cells in parallel with a reduction of the peak amplitude of tic events in the electromyography record. This finding supports the premise that deep brain stimulation targeted to the globus pallidus internus could be a viable treatment option for Tourette syndrome, and the use of pallidal stimulation for motor tics warrants further study.
authors.affiliation: Unit on Neural Systems and Behavior, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan. kevin.mccairn@yahoo.com
authors.forename: Kevin W
authors.initials: KW
authors.lastname: McCairn
authors.forename: Atsushi
authors.initials: A
authors.lastname: Iriki
authors.forename: Masaki
authors.initials: M
authors.lastname: Isoda
mesh_terms: D000818:Animals; D046690:Deep Brain Stimulation / Q000379:methods*; D004195:Disease Models, Animal; D005917:Globus Pallidus / Q000502:physiology / Q000601:surgery*; D008253:Macaca mulatta; D008297:Male; D009474:Neurons / Q000473:pathology*; D020323:Tics / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*; D005879:Tourette Syndrome / Q000473:pathology / Q000628:therapy*; D016896:Treatment Outcome