Microelectrode-Guided Deep Brain Stimulation for Tourette Syndrome: Within-Subject Comparison of Different Stimulation Sites

Abstract

Background: As medical therapy for Tourette syndrome (TS) is ineffective in a small subset of patients, surgical interventions, including deep brain stimulation at various sites, have been developed in recent years. Case Description: We present the case of a 40-year-old woman with TS whose severe tics had caused unilateral blindness. Despite trials of more than 40 medications, her symptoms improved significantly only after placement of bilateral deep brain stimulators in the anterior inferior internal capsule. However, symptomatic improvement was not complete, and her electrode connections eventually became permanently damaged by the remaining retrocollic jerks. She underwent removal of the internal capsule electrodes and placement of centromedian nucleus thalamic stimulators with significantly improved tic control. Conclusion: Whereas the anterior internal capsule site had also produced psychiatric side effects such as altered mood and impulse control, the thalamic site has not done so to date. Thus, distinct surgical targets for TS may be appropriate for patients with specific comorbidities.

Deep Brain Stimulation for Tourette Syndrome: Target Selection

“…At 18 months follow-up, the patient experienced a 23% improvement in global severity on the YGTSS. As the patient did not experience a more complete resolution of her tics, when a hardware malfunction occurred, she was revised to the thalamic target with a 46% decrease in global severity on the YGTSS [49]. …”

“…Only three studies provide some insight into the relative efficacy of the various surgical targets used for DBS in TS [35,42,49]. Van der Linden et al [35] compared posteroventral pallidal stimulation with medial thalamic stimulation and Welter et al [42] compared ventromedial pallidal stimulation with medial thalamic stimulation.…”

“…All 4 patients reported in these two studies experienced greater reduction in tic scores with pallidal stimulation than with thalamic stimulation. The only other direct comparison that exists is the report by Shields et al [49]. Their patient was initially implanted in the anterior limb internal capsule with a 23% reduction in the YGTSS score and was revised to the thalamic target with a greater reduction (46%) in the YGTSS score.…”

Issues Related to Deep Brain Stimulation for Treatment-Refractory Tourette’s Syndrome

“…0.001 vs. baseline) [Servello et al, 2008]. In a recent case report, a woman with severe refractory Tourette's syndrome despite DBS of the anterior internal capsule achieved significant improvement in tic control at 3 months following bilateral centromedian thalamic stimulation (reduction in total tic score: 42% compared with pre-DBS baseline and 27% compared with DBS of the postinternal capsule) and a reduction in psychiatric side effects such as altered mood and impulse control compared with internal capsule stimulation [Shields et al, 2008].…”

“…Although clinical studies of DBS in patients with Tourette's syndrome have involved very small numbers of patients to date, results have generally been favorable ( table 1 ) [Vandewalle et al, 1999;Van der Linden et al, 2002;Visser-Vandewalle et al, 2003;Diederich et al, 2005;Flaherty et al, 2005;Houeto et al, 2005;Porta et al, 2005;Ackermans et al, 2006;Gallagher et al, 2006;Bajwa et al, 2007;Kuhn et al, 2007;Maciunas et al, 2007;Shahed et al, 2007;Dehning et al, 2008;Shields et al, 2008;Welter et al, 2008].…”