Long-term effects of bilateral pallidal deep brain stimulation in dystonia: a follow-up between 8 and 16 years.

OBJECTIVE: Observational study to evaluate the long-term motor and non-motor effects of deep brain stimulation (DBS) of the globus pallidus internus (GPi) on medically refractory dystonia. BACKGROUND: Dystonia is a chronic disease affecting mainly young patients with a regular life expectancy and lifelong need for therapy. Pallidal DBS is an established treatment for severe isolated dystonia but long-term data are sparse. METHODS: We considered 36 consecutive patients with isolated generalized (n = 14) and cervical/segmental (n = 22) dystonia operated at Charité-University Hospital between 2000 and 2007 in a retrospective analysis for long-term outcome of pallidal DBS. In 19 of these patients, we could analyze dystonic symptoms and disability rated by the Burke-Fahn-Marsden Dystonia Rating scale (BFMDRS) at baseline, short-term (ST-FU, range 3-36 months) and long-term follow-up (LT-FU, range 93-197 months). Quality of life and mood were evaluated using the SF36 and Beck Depression Index (BDI) questionnaires. RESULTS: Patients reached an improvement in motor symptoms of 63.8 ± 5.7% (mean ± SE) at ST-FU and 67.9 ± 6.1% at LT-FU. Moreover, a significant and stable reduction in disability was shown following DBS (54.2 ± 9.4% at ST-FU and 53.8 ± 9.2% at LT-FU). BDI and SF36 had improved by 40% and 23%, respectively, at LT-FU (n = 14). Stimulation-induced adverse events included swallowing difficulties, dysarthria, and bradykinesia. Pulse generator (n = 3) and electrodes (n = 5) were revised in seven patients due to infection. CONCLUSIONS: Pallidal DBS is a safe and efficacious long-term treatment for dystonia with sustained effects on motor impairment and disability, accompanied by a robust improvement in mood and quality of life.

Adverse events associated with deep brain stimulation in patients with childhood-onset dystonia.

BACKGROUND: Data on pediatric DBS is still limited because of small numbers in single center series and lack of systematic multi-center trials. OBJECTIVES: We evaluate short- and long-term adverse events (AEs) of patients undergoing deep brain stimulation (DBS) during childhood and adolescence. METHODS: Data collected by the German registry on pediatric DBS (GEPESTIM) were analyzed according to reversible and irreversible AEs and time of occurrence with relation to DBS-surgery: Intraoperative, perioperative (<4 weeks), postoperative (4 weeks < 6 months) and long term AEs (>6 months). RESULTS: 72 patients with childhood-onset dystonia from 10 DBS-centers, who received 173 DBS electrodes and 141 implantable pulse generators (IPG), were included in the registry. Mean time of postoperative follow-up was 4.6 ±â€¯4 years. In total, 184 AEs were documented in 53 patients (73.6%). 52 DBS-related AEs in 26 patients (36.1%) required 45 subsequent surgical interventions 4.7 ±â€¯4.1 years (range 3 months-15 years) after initial implantation. The total risk of an AE requiring surgical intervention was 7.9% per electrode-year. Hardware-related AEs were the most common reason for surgery. There was a tendency of a higher rate of AEs in patients aged 7-9 years beyond 6 months after implantation. DISCUSSION: The intraoperative risk of AEs in pediatric patients with dystonia undergoing DBS is very low, whereas the rate of postoperative hardware-related AEs is a prominent feature with a higher occurrence compared to adults, especially on long-term follow-up. CONCLUSION: Factors leading to such AEs must be identified and patient management has to be focused on risk minimization strategies in order to improve DBS therapy and maximize outcome in pediatric patients.

German registry of paediatric deep brain stimulation in patients with childhood-onset dystonia (GEPESTIM).

BACKGROUND: Data on paediatric deep brain stimulation (DBS) is limited, especially for long-term outcomes, because of small numbers in single center series and lack of systematic multi-center trials. OBJECTIVES: We seek to systematically evaluate the clinical outcome of paediatric patients undergoing DBS. METHODS: A German registry on paediatric DBS (GEPESTIM) was created to collect data of patients with dystonia undergoing DBS up to the age of 18 years. Patients were divided into three groups according to etiology (group 1 inherited, group 2 acquired, and group 3 idiopathic dystonia). RESULTS: Data of 44 patients with a mean age of 12.8 years at time of operation provided by 6 German centers could be documented in the registry so far (group 1 n = 18, group 2 n = 16, group 3 n = 10). Average absolute improvement after implantation was 15.5 ± 18.0 for 27 patients with pre- and postoperative Burke-Fahn-Marsden Dystonia Rating scale movement scores available (p < 0.001) (group 1: 19.6 ± 19.7, n = 12; group 2: 7.0 ± 8.9, n = 8; group 3: 19.2 ± 20.7, n = 7). Infection was the main reason for hardware removal (n = 6). 20 IPG replacements due to battery expiry were necessary in 15 patients at 3.7 ± 1.8 years after last implantation. DISCUSSION: Pre- and postoperative data on paediatric DBS are very heterogeneous and incomplete but corroborate the positive effects of DBS on inherited and acquired dystonia. Adverse events including relatively frequent IPG replacements due to battery expiry seem to be a prominent feature of children with dystonia undergoing DBS. The registry enables collaborative research on DBS treatment in the paediatric population and to create standardized management algorithms in the future.

Long-term results of deep brain stimulation in a cohort of eight children with isolated dystonia.

Pallidal deep brain stimulation (DBS) is an established treatment for patients with severe isolated dystonia. However, clinical evidence for the long-term use of DBS in children is limited and controlled trials have not yet been conducted. Here, we provide the long-term results of up to 13 years of pallidal DBS in eight pediatric patients with generalized idiopathic or hereditary isolated dystonia (five males, mean age at surgery 12.5 ± 3.5 years), as assessed by retrospective video rating. Video rating was performed at three time points: pre-operative, 1-year short-term follow-up (1y-FU) and long-term last FU (LT-FU, up to 13 years). Symptom severity and disability were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). Disability scores were obtained from clinical charts and during the last FU. The mean improvement in BFMDRS motor score was 54.4 ± 8.9 % at 1y-FU and 42.9 ± 11.6 % at LT-FU; the disability scores improved by 59.8 ± 10.3 and 63.3 ± 7.8 %, respectively. Electrode dislocation was noted in one patient and implantable pulse generator dislocation in another, both requiring surgical intervention; no further serious adverse events occurred. Our study presents the first blinded video rating assessment of the short- and long-term effects of pallidal DBS in children with idiopathic or hereditary isolated dystonia. Results confirm that pallidal DBS is a safe and efficacious long-term treatment in children, with overall motor improvement similar to that described in controlled trials in adults.

Long-term effect on dystonia after pallidal deep brain stimulation (DBS) in three members of a family with a THAP1 mutation.

Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is an established treatment in patients with severe dystonia. However, factors predicting outcome are largely unknown and motor improvement in DYT6 patients after DBS has been reported to be poorer as compared to, e.g., DYT1 patients. Here, we report the course of clinical improvement for up to 11 years of pallidal DBS in three male patients belonging to the same family with early-onset generalized or segmental dystonia due to a heterozygous THAP1 gene mutation (DYT6). All patients showed an initial effective response to pallidal DBS with a mean of 56.9 ± 11.7% improvement in the Burke-Fahn-Marsden Dystonia motor and 45.5 ± 22.4% in the disability score at 1-year follow-up. The long-term outcome of pallidal DBS was favorable in two patients (39, 67% motor improvement, respectively). Our findings demonstrate that motor improvement is variable and may depend on disease severity, disease duration, and clinical presentation. Overall, our observation supports pallidal DBS as an important treatment option in patients with DYT6 dystonia.

Interhemispheric functional interactions between the subthalamic nuclei of patients with Parkinson's disease.

Parkinson's disease (PD) is characterized by widespread neural interactions in cortico-basal-ganglia networks primarily in beta oscillations (approx. 10-30 Hz), as suggested by previous findings of levodopa-modulated interhemispheric coherence between the bilateral subthalamic nuclei (STN) in local field potential recordings (LFPs). However, due to confounding effects of volume conduction the existence of 'genuine' interhemispheric subcortical coherence remains an open question. To address this issue we utilized the imaginary part of coherency (iCOH) which, in contrast to the standard coherence, is not susceptible to volume conduction. LFPs were recorded from eight patients with PD during wakeful rest before and after levodopa administration. We demonstrated genuine coherence between the bilateral STN in both 10-20 and 21-30 Hz oscillations, as revealed by a non-zero iCOH. Crucially, increased iCOH in 10-20 Hz oscillations positively correlated with the worsening of motor symptoms in the OFF medication condition across patients, which was not the case for standard coherence. Furthermore, across patients iCOH was increased after levodopa administration in 21-30 Hz oscillations. These results suggest a functional distinction between low and high beta oscillations in STN-LFP in line with previous studies. Furthermore, the observed functional coupling between the bilateral STN might contribute to the understanding of bilateral effects of unilateral deep brain stimulation. In conclusion, the present results imply a significant contribution of time-delayed neural interactions to interhemispheric coherence, and the clinical relevance of long-distance neural interactions between bilateral STN for motor symptoms in PD.

Quadruple deep brain stimulation in Huntington's disease, targeting pallidum and subthalamic nucleus: case report and review of the literature.

Deep brain stimulation (DBS) represents an established treatment option in a growing number of movement disorders. Recent case reports suggest beneficial effect of globus pallidus internus (GPi)-DBS in selected patients suffering from Huntington's disease with marked disabling chorea. We present a 41-year-old man with genetically confirmed HD following quadruple GPi- and subthalamic nucleus (STN)-DBS. Motor function was assessed by Abnormal Involuntary Movement Scale (AIMS) and by Unified Huntington Disease Rating Scale (UHDRS) presurgery and postsurgery for up to 4 years. Furthermore, cognitive, neuropsychiatric state and quality of life (QoL) including life satisfaction (QLS) were annually evaluated. Chorea assessed by AIMS and UHDRS subscores improved by 52 and 55 %, 45 and 60 %, 35 and 45 % and 55-66 % at 1-4 years, respectively, compared to presurgical state following GPi-STN-DBS. During these time periods bradykinesia did not increase following separate STN- and combined GPi-STN-DBS compared to presurgical state. Mood, QoL and QLS were ameliorated. However, dysexecutive symptoms increased at 4 years postsurgery. The present case report suggests that bilateral GPi- and STN-DBS may represent a new treatment avenue in selected HD patients. Clinically, GPi-DBS attenuated chorea and was associated with a larger effect-adverse effect window compared to STN-DBS. However, GPi-DBS-induced bradykinesia may emerge as one main limitation of GPi-DBS in HD. Thus, quadruple GPi-STN-DBS may be indicated, if separate GPi-DBS does not result in sufficient control of motor symptoms. Future controlled studies need to confirm if the present anecdotal observation of additive beneficial effects of GPi- and STN-DBS in a HD patient with severe generalized chorea and relatively intact cognitive and affective functions indeed represents a new therapeutic option.

Different patterns of local field potentials from limbic DBS targets in patients with major depressive and obsessive compulsive disorder.

The role of distinct limbic areas in emotion regulation has been largely inferred from neuroimaging studies. Recently, the opportunity for intracranial recordings from limbic areas has arisen in patients undergoing deep brain stimulation (DBS) for neuropsychiatric disorders including major depressive disorder (MDD) and obsessive compulsive disorder (OCD). Here we test the hypothesis that distinct temporal patterns of local field potential (LFP) activity in the human limbic system reflect disease state and symptom severity in MDD and OCD patients. To this end, we recorded LFPs via implanted DBS electrodes from the bed nucleus of stria terminalis (BNST area) in 12 patients (5 OCD, 7 MDD) and from the subgenual cingulate cortex in 7 MDD patients (CG25 area). We found a distinct pattern of oscillatory activity with significantly higher α-power in MDD compared with OCD in the BNST area (broad α-band 8-14 Hz; P<0.01) and a similar level of α-activity in the CG25 area as in the BNST area in MDD patients. The mean α-power correlated with severity of depressive symptoms as assessed by the Beck depression inventory in MDD (n=14, r=0.55, P=0.042) but not with severity of obsessive compulsive symptoms in OCD. Here we show larger α-band activity in MDD patients compared with OCD recorded from intracranial DBS targets. Our results suggest that α-activity in the limbic system may be a signature of symptom severity in MDD and may serve as a potential state biomarker for closed loop DBS in MDD.

Functional and effective connectivity in subthalamic local field potential recordings of patients with Parkinson's disease.

In Parkinson's disease (PD) levodopa-associated changes in the power and long-range temporal correlations of beta oscillations have been demonstrated, yet the presence and modulation of genuine connectivity in local field potentials (LFP) recorded from the subthalamic nucleus (STN) remains an open question. The present study investigated LFP recorded bilaterally from the STN at wakeful rest in ten patients with PD after overnight withdrawal of levodopa (OFF) and after a single dose levodopa administration (ON). We utilized connectivity measures being insensitive to volume conduction (functional connectivity: non-zero imaginary part of coherency; effective connectivity: phase-slope index). We demonstrated the presence of neuronal interactions in the frequency range of 10-30 Hz in STN-LFP without a preferential directionality of interactions between different contacts along the electrode tracks. While the direction of neuronal interactions per se was preserved after levodopa administration, functional connectivity and the ventral-dorsal information flow were modulated by medication. The OFF-ON differences in functional connectivity were correlated with the levodopa-induced improvement in clinical Unified Parkinson's Disease Rating Scale scores. We hypothesize that regional neuronal interactions, as reflected in STN-LFP connectivity, might represent a basis for the intra-nuclear spatial specificity of deep brain stimulation. Moreover, our results suggest the potential use of volume conduction-insensitive measures of connectivity in STN-LFP as a marker of clinical motor symptoms in PD.

Neurostimulation for Parkinson's disease with early motor complications.

BACKGROUND: Subthalamic stimulation reduces motor disability and improves quality of life in patients with advanced Parkinson's disease who have severe levodopa-induced motor complications. We hypothesized that neurostimulation would be beneficial at an earlier stage of Parkinson's disease. METHODS: In this 2-year trial, we randomly assigned 251 patients with Parkinson's disease and early motor complications (mean age, 52 years; mean duration of disease, 7.5 years) to undergo neurostimulation plus medical therapy or medical therapy alone. The primary end point was quality of life, as assessed with the use of the Parkinson's Disease Questionnaire (PDQ-39) summary index (with scores ranging from 0 to 100 and higher scores indicating worse function). Major secondary outcomes included parkinsonian motor disability, activities of daily living, levodopa-induced motor complications (as assessed with the use of the Unified Parkinson's Disease Rating Scale, parts III, II, and IV, respectively), and time with good mobility and no dyskinesia. RESULTS: For the primary outcome of quality of life, the mean score for the neurostimulation group improved by 7.8 points, and that for the medical-therapy group worsened by 0.2 points (between-group difference in mean change from baseline to 2 years, 8.0 points; P=0.002). Neurostimulation was superior to medical therapy with respect to motor disability (P<0.001), activities of daily living (P<0.001), levodopa-induced motor complications (P<0.001), and time with good mobility and no dyskinesia (P=0.01). Serious adverse events occurred in 54.8% of the patients in the neurostimulation group and in 44.1% of those in the medical-therapy group. Serious adverse events related to surgical implantation or the neurostimulation device occurred in 17.7% of patients. An expert panel confirmed that medical therapy was consistent with practice guidelines for 96.8% of the patients in the neurostimulation group and for 94.5% of those in the medical-therapy group. CONCLUSIONS: Subthalamic stimulation was superior to medical therapy in patients with Parkinson's disease and early motor complications. (Funded by the German Ministry of Research and others; EARLYSTIM ClinicalTrials.gov number, NCT00354133.).

Long-range temporal correlations in the subthalamic nucleus of patients with Parkinson's disease.

Neuronal activity in the subthalamic nucleus (STN) of patients with Parkinson's disease (PD) is characterised by excessive neuronal synchronization, particularly in the beta frequency range. However, less is known about the temporal dynamics of neuronal oscillations in PD. In this respect long-range temporal correlations (LRTC) are of special interest as they quantify the neuronal dynamics on different timescales and have been shown to be relevant for optimal information processing in the brain. While the presence of LRTC has been demonstrated in cortical data, their existence in deep brain structures remains an open question. We investigated (i) whether LRTC are present in local field potentials (LFP) recorded bilaterally from the STN at wakeful rest in ten patients with PD after overnight withdrawal of levodopa (OFF) and (ii) whether LRTC can be modulated by levodopa treatment (ON). Detrended fluctuation analysis was utilised in order to quantify the temporal dynamics in the amplitude fluctuations of LFP oscillations. We demonstrated for the first time the presence of LRTC (extending up to 50 s) in the STN. Importantly, the ON state was characterised by significantly stronger LRTC than the OFF state, both in beta (13-35 Hz) and high-frequency (> 200 Hz) oscillations. The existence of LRTC in subcortical structures such as STN provides further evidence for their ubiquitous nature in the brain. The weaker LRTC in the OFF state might indicate limited information processing in the dopamine-depleted basal ganglia. The present results implicate LRTC as a potential biomarker of pathological neuronal processes in PD.

Automated optimization of subcortical cerebral MR imaging-atlas coregistration for improved postoperative electrode localization in deep brain stimulation.

BACKGROUND AND PURPOSE: The efficacy of deep brain stimulation in treating movement disorders depends critically on electrode localization, which is conventionally described by using coordinates relative to the midcommissural point. This approach requires manual measurement and lacks spatial normalization of anatomic variances. Normalization is based on intersubject spatial alignment (coregistration) of corresponding brain structures by using different geometric transformations. Here, we have devised and evaluated a scheme for automated subcortical optimization of coregistration (ASOC), which maximizes patient-to-atlas normalization accuracy of postoperative structural MR imaging into the standard Montreal Neurologic Institute (MNI) space for the basal ganglia. MATERIALS AND METHODS: Postoperative T2-weighted MR imaging data from 39 patients with Parkinson disease and 32 patients with dystonia were globally normalized, representing the standard registration (control). The global transformations were regionally refined by 2 successive linear registration stages (RSs) (ASOC-1 and 2), focusing progressively on the basal ganglia with 2 anatomically selective brain masks, which specify the reference volume (weighted cost function). Accuracy of the RSs was quantified by spatial dispersion of 16 anatomic landmarks and their root-mean-square errors (RMSEs) with respect to predefined MNI-based reference points. The effects of CSF volume, age, and sex on RMSEs were calculated. RESULTS: Mean RMSEs differed significantly (P < .001) between the global control (4.2 +/- 2.0 mm), ASOC-1 (1.92 +/- 1.02 mm), and ASOC-2 (1.29 +/- 0.78 mm). CONCLUSIONS: The present method improves the registration accuracy of postoperative structural MR imaging data into MNI space within the basal ganglia, allowing automated normalization with increased precision at stereotactic targets, and enables lead-contact localization in MNI coordinates for quantitative group analysis.

Long-term effects of pallidal deep brain stimulation in tardive dystonia.

OBJECTIVE: High-frequency stimulation of the globus pallidus internus (GPi) is a highly effective therapy in primary dystonia. Recent reports have also demonstrated almost immediate improvement of motor symptoms in patients with tardive dystonia after pallidal deep brain stimulation (DBS). Here, we show the long-term effect of continuous bilateral GPi DBS in tardive dystonia on motor function, quality of life (QoL), and mood. METHODS: Nine consecutive patients undergoing DBS for tardive dystonia were assessed during continuous DBS at 3 time points: 1 week, 3 to 6 months, and last follow-up at the mean of 41 (range 18-80) months after surgery using established and validated movement disorder and neuropsychological scales. Clinical assessment was performed by a neurologist not blinded to the stimulation settings. RESULTS: One week and 3 to 6 months after pallidal DBS, Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) motor scores were ameliorated by 56.4 +/- 26.7% and 74.1 +/- 15.8%, BFMDRS disability scores by 62.5 +/- 21.0% and 88.9 +/- 10.3%, and Abnormal Involuntary Movement Scale (AIMS) scores by 52.3 +/- 24.1% and 69.5 +/- 27.6%, respectively. At last follow-up, this improvement compared with the presurgical assessment was maintained as reflected by a reduction of BFMDRS motor scores by 83.0 +/- 12.2%, BFMDRS disability scores by 67.7 +/- 28.0%, and AIMS scores by 78.7 +/- 19.9%. QoL improved significantly in physical components, and there was a significant improvement in affective state. Furthermore, cognitive functions remained unchanged compared with presurgical status in the long-term follow-up. No permanent adverse effects were observed. CONCLUSION: Pallidal deep brain stimulation is a safe and effective long-term treatment in patients with medically refractory tardive dystonia.

Anticipatory activity in the human thalamus is predictive of reaction times.

Responding to environmental stimuli in a fast manner is a fundamental behavioral capacity. The pace at which one responds is known to be predetermined by cortical areas, but it remains to be shown if subcortical structures also take part in defining motor swiftness. As the thalamus has previously been implicated in behavioral control, we tested if neuronal activity at this level could also predict the reaction time of upcoming movements. To this end we simultaneously recorded electrical brain activity from the scalp and the ventral intermediate nucleus (VIM) of the thalamus in patients undergoing thalamic deep brain stimulation. Based on trial-to-trial analysis of a Go/NoGo task, we demonstrate that both cortical and thalamic neuronal activity prior to the delivery of upcoming Go stimulus correlates with the reaction time. This result goes beyond the demonstration of thalamic activity being associated with but potentially staying invariant to motor performance. In contrast, it indicates that the latencies at which we respond to environmental stimuli are not exclusively related to cortical pre-movement states but are also correlated with anticipatory thalamic activity.

The subthalamic region is activated during valence-related emotional processing in patients with Parkinson's disease.

Visual stimuli are judged for their emotional significance based on two fundamental dimensions, valence and arousal, and may lead to changes in neural and body functions like attention, affect, memory and heart rate. Alterations in behaviour and mood have been encountered in patients with Parkinson's disease (PD) undergoing functional neurosurgery, suggesting that electrical high-frequency stimulation of the subthalamic nucleus (STN) may interfere with emotional information processing. Here, we use the opportunity to directly record neuronal activity from the STN macroelectrodes in patients with PD during presentation of emotionally laden and neutral pictures taken from the International Affective Picture System (IAPS) to further elucidate the role of the STN in emotional processing. We found a significant event-related desynchronization of STN alpha activity with pleasant stimuli that correlated with the individual valence rating of the pictures. Our findings suggest involvement of the human STN in valence-related emotional information processing that can potentially be altered during high-frequency stimulation of the STN in PD leading to behavioural complications.

["Asleep-awake-asleep"-anaesthetic technique for awake craniotomy]. / "Schlaf-Wach-Schlaf"-Technik zur CS Wachkraniotomie.

Awake craniotomy in tumor and epilepsy surgery or for the implantation of electrodes for deep brain stimulation requires specific anesthesiological strategies. Propofol allows for quick emergence and has little effect on the respiratory function of the usually spontaneously breathing patient. Pain control may be instituted by hemiscalp block for trepanation or local infiltration for deep brain electrode implantation. In addition, low dose remifentanil is recommended for trepanation (i.e. tumor or epilepsy surgery). The airway may be secured by an ordinary Magill tube placed transnasally with its tip underneath the epiglottis. To protect the patient against vomiting an adequate antiemetic prophylaxis is required.

Oscillatory pallidal local field potential activity correlates with involuntary EMG in dystonia.

The pathophysiology of dystonia is unclear. The authors recorded local field potentials (LFPs) from deep brain stimulation electrodes implanted in the pallidum of 13 dystonic patients. LFP power correlated with the level of dystonic EMG in the sternocleidomastoid, with maximal positive correlations at the lower contacts of pallidal electrodes. The data suggest that the neuronal synchronization indexed by LFP oscillations in the globus pallidus may be mechanistically linked to dystonic EMG activity.

Pallidal stimulation in dystonia: effects on cognition, mood, and quality of life.

Bilateral deep brain stimulation (DBS) of the globus pallidus internus (GPi) alleviates symptoms in patients with dystonia but its effects on cognition, neuropsychiatric status, and quality of life have not been examined. This is a case series report of 15 consecutive patients with different forms of dystonia who underwent bilateral implantation of DBS electrodes in the GPi. The patients were evaluated preoperatively and after 3-12 months of DBS with tests of cognition (Mattis Dementia Rating Scale, Stroop Test, Trail Making Test, Phonemic and Category Word Fluency, Digit Span, Rey Auditory Verbal Learning Test, Tonic and Phasic Alertness), neuropsychiatric status (Beck Depression and Anxiety Inventories, Montgomery Asberg Depression Rating Scale, Snaith-Hamilton Pleasure Scale, Brief Psychiatric Rating Scale), quality of life, and motor functions. GPi DBS significantly improved dystonic symptoms, functional abilities, and quality of life allowing for a significant reduction of antidystonic medications. No deterioration was observed in cognitive scores and neuropsychiatric measures. The present case series report thus provides preliminary evidence for the safety of GPi DBS regarding cognitive and neuropsychiatric functions in patients with dystonia.

Activation of the subthalamic region during emotional processing in Parkinson disease.

OBJECTIVE: To elucidate the involvement of the human subthalamic nucleus (STN) region in the processing or transmission of emotional information. METHODS: Local field potentials (LFPs) were recorded from this region in 10 patients with Parkinson disease (PD) undergoing bilateral implantation of the STN for high-frequency stimulation. LFP recordings were made while patients viewed pleasant and unpleasant emotionally arousing and neutral pictures. RESULTS: A significant decrease (event-related desynchronization [ERD]) in the local alpha power (8 to 12 Hz) was found for all stimulus categories starting at about 0.5 seconds after stimulus presentation. However, 1 to 2 seconds poststimulus, the ERD was larger in trials of pleasant (mean ERD: 21.6 +/- 2.8%; p < 0.009) and unpleasant (mean ERD: 15.0 +/- 4.2%; p = 0.018) stimuli compared with neutral stimuli (mean ERD: 4.4 +/- 4.2%). CONCLUSION: The delayed modulation of alpha activity recorded from the area of the subthalamic nucleus in PD may reflect the processing or transmission of information related to emotional stimuli. "Limbic" activation in the region of the subthalamic nucleus may explain why high-frequency stimulation of the subthalamic nucleus alters affect in some patients with PD.