DBS is a useful and safe treatment for severe GTS. The results of ours and previous DBS reports suggest that the CM-Pfc and ventralis oralis complex of the thalamus may be a good DBS target for GTS.

This study provides class IV evidence that bilateral thalamic deep brain stimulation reduces global tic severity measured 24 months after implantation in patients with severe intractable Tourette syndrome.

No abstract

There is debate over the cognitive and behavioral effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD). To evaluate these effects, we performed a prospective, naturalistic controlled, 3-year follow-up study. A total of 65 PD patients were enrolled, of whom 32 underwent STN-DBS (PD-DBS) and 33, even though eligible for this treatment, declined surgery and chose other therapeutic procedures (PD-control). Motor and neuropsychological functions were assessed in all the subjects at baseline (T0) and 36 months (T36). The PD-DBS patients were also evaluated at 1, 6, 12, and 24 months after surgery (T1, T6, T12, and T24). At T1, compared with T0, the PD-DBS patients recorded worse logical executive function task and verbal fluency (FAS) scores, whereas their performance of memory tasks remained stable. At T12, their cognitive profile had returned within the pre-DBS range, thereafter remaining stable until T36. FAS scores at T36 were significantly worse in the PD-DBS compared with the PD-control patients. This is the first long-term naturalistic controlled study of cognitive functions in PD patients submitted to STN-DBS. Our results confirm previous reports of a worsening of verbal fluency after DBS, but show that STN-DBS seems to be relatively safe from a cognitive standpoint, as the short-term worsening of frontal-executive functions was found to be transient.

No abstract

In the past years, local field potential (LFP) signals recorded from the subthalamic nucleus (STN) in patients undergoing deep brain stimulation (DBS) for Parkinson’s disease (PD) disclosed that DBS has a controversial effect on STN beta oscillations recorded 2–7 days after surgery for macroelectrode implantation. Nothing is known about these DBS-induced oscillatory changes 30 days after surgery. We recorded STN LFPs during ongoing DBS in 7 patients with PD, immediately (hyperacute phase) and 30 days (chronic phase) after surgery. STN LFP recordings showed stationary intranuclear STN beta LFP activity in hyperacute and chronic phases, confirming that beta peaks were also present in chronic recordings. Power spectra of nuclei with significant beta activity (54% of the sample) showed that it decreased significantly during DBS (p = 0.021) under both recording conditions. The time course of beta activity showed more evident DBS-induced changes in the chronic than in the hyperacute phase (p = 0.014). DBS-induced changes in STN beta LFPs in patients undergoing DBS in chronic phase provide useful information for developing a new neurosignal-controlled adaptive DBS system.

Invasive treatment for Gilles de la Tourette syndrome has shown interesting results in a number of published reports; it seems to be evolving into a promising therapeutic procedure for those patients demonstrating disabling clinical pictures who are refractory to conservative treatments. There are important issues concerning the stimulated brain target, with different nuclei currently under investigation. Our group asked in this pilot study whether Tourette syndrome could be treated by tailoring specific brain targets for specific symptoms. Deep brain stimulation for Tourette syndrome may thus in the future be tailored and patient specific, utilizing specific target regions for individual clinical manifestations. In our early experience we did not adequately address non-motor clinical symptoms as we only used a thalamic target. More recently in an obsessive compulsive disease cohort we have had success in using the anterior limb of the internal capsule and nucleus accumbens region as targets for stimulation. We therefore explored the option of a "rescue" procedure for our Tourette patients with persistent obsessive-compulsive disorder following ventralis oralis/centromedianus-parafascicularis (Vo/CM-Pf) deep brain stimulation. Following two cases where rescue anterior limb of internal capsule/nucleus accumbens leads were employed, we performed two additional procedures (anterior limb of the internal capsule plus ventralis oralis/centromedianus-parafascicularis and anterior limb of the internal capsule alone) with some mild improvement of comorbid obsessive-compulsive disorder, although the number of observations in this case series was low. Overall, the effects observed with using the anterior limb of the internal capsule either alone or as a rescue were less than expected. In this report we detail our experience with this approach.

Deep brain stimulation (DBS) of the ventralis oralis (VO) complex of the thalamus improves tics in patients with Tourette syndrome (TS). To neurophysiologically describe the VO complex we recorded, in seven patients with TS undergoing DBS electrode implantation, single-unit activity during surgery and local field potentials (LFPs) a few days after surgery. Single unit recordings showed that the VO complex is characterized by a localized pattern of bursting neuronal activity. LFP spectra demonstrated that VO of TS patients has a prominent oscillatory activity at low frequencies (2-7 Hz) and in the alpha-band (8-13 Hz), and a virtually absent beta activity. In each patient, the main LFP frequency significantly correlated with single-unit interburst frequency. In conclusion, we observed an oscillatory bursting activity in the VO as target region in patients with severe TS undergoing DBS surgery.