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Background: Although deep brain stimulation of the globus pallidus internus (GPi-DBS) is an established treatment for many forms of dystonia, including generalized as well as focal forms, its effects on brain (dys-)function remain to be elucidated, particularly for focal and segmental dystonia. Clinical response to GPi-DBS typically comes with some delay and lasts up to several days, sometimes even weeks, once stimulation is discontinued., Objective: This study investigated how neural activity during rest and motor activation is affected by GPi-DBS while excluding the potential confound of altered feedback as a result of therapy-induced differences in dystonic muscle contractions., Methods: Two groups of patients with focal or segmental dystonia were included in the study: 6 patients with GPi-DBS and 8 without DBS (control group). All 14 patients had cervical dystonia. Using H 2 15 O PET, regional cerebral blood flow was measured at rest and during a motor task performed with a nondystonic hand., Results: In patients with GPi-DBS (stimulation ON and OFF), activity at rest was reduced in a prefrontal network, and during the motor task, sensorimotor cortex activity was lower than in patients without DBS. Within-group contrasts (tapping > rest) showed less extensive task-induced motor network activation in GPi-DBS patients than in non-DBS controls. Reduced sensorimotor activation amounted to a significant group-by-task interaction only in the stimulation ON state., Conclusions: These findings support previous observations in generalized dystonia that suggested that GPi-DBS normalizes dystonia-associated sensorimotor and prefrontal hyperactivity, indicating similar mechanisms in generalized and focal or segmental dystonia. Evidence is provided that these effects extend into the OFF state, which was not previously demonstrated by neuroimaging. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society., (© 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.)

Introduction: Growing evidence suggests that pallidal deep brain stimulation represents a potential new therapeutic avenue in tardive dystonia/dyskinesia, but controlled and blinded randomized studies (RCT) are missing. The present RCT compares dystonia/dyskinesia severity of pallidal neurostimulation in patients with tardive dystonia using a delayed-start design paradigm., Methods: Dystonia/dyskinesia severity was assessed via blinded videos following pallidal neurostimulation at 3 (blinded phase) and 6 months (open extension phase). Primary endpoint was the percentage change of dystonia severity (Burke-Fahn-Marsden-Dystonia-Rating-Scale, BFMDRS) at 3 months between active vs. sham neurostimulation using blinded-video assessment. Secondary endpoints comprised clinical rating scores for movement disorders. Clinicaltrials.gov NCT00331669., Results: Twenty-five patients were randomized (1:1) to active (n = 12) or sham neurostimulation (n = 13). In the intention-to-treat analyses the between group difference of dystonia severity (BFMDRS) between active vs. sham stimulation was not significant at 3 months. Three months post-randomisation dystonia severity improved significantly within the neurostimulation by 22.8% and non-significantly within the sham group (12.0%) compared to their respective baseline severity. During the open-label extension with both groups being actively treated, significant and pronounced improvements of 41.5% were observed via blinded evaluation. Adverse events (n = 10) occurred in 10/25 of patients during the 6 months, mostly related to surgical implantation of the device; all resolved without sequelae., Conclusion: The primary endpoint of this randomized trial was not significant, most likely due to incomplete recruitment. However, pronounced improvements of most secondary endpoints at 3 and 6 months provide evidence for efficacy and safety of pallidal neurostimulation in tardive dystonia., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: Pallidal deep brain stimulation (GPi-DBS) is an effective therapy for isolated dystonia, but 10-20% of patients show improvement below 25-30%. We here investigated causes of insufficient response to GPi-DBS in isolated dystonia in a cross-sectional study., Methods: Patients with isolated dystonia at time of surgery, and <30% improvement on the Burke-Fahn-Marsden dystonia-rating-scale (BFMDRS) after ≥6 months of continuous GPi-DBS were videotaped ON and OFF stimulation, and history, preoperative videos, brain MRI, medical records, stimulation settings, stimulation system integrity, lead location, and genetic information were obtained and reviewed by an expert panel., Results: 22 patients from 11 centres were included (8 men, 14 women; 9 generalized, 9 segmental, 3 focal, 1 bibrachial dystonia; mean (range): age 48.7 (25-72) years, disease duration 22.0 (2-40) years, DBS duration 45.5 (6-131) months). Mean BFMDRS-score was 31.7 (4-93) preoperatively and 32.3 (5-101) postoperatively. Half of the patients (n = 11) had poor lead positioning alone or in combination with other problems (combined with: other disease n = 6, functional dystonia n = 1, other problems n = 2). Other problems were disease other than isolated inherited or idiopathic dystonia (n = 5), fixed deformities (n = 2), functional dystonia (n = 3), and other causes (n = 1). Excluding patients with poor lead location from further analysis, non-isolated dystonia accounted for 45.5%, functional dystonia for 27.3%, and fixed deformities for 18.2%. In patients with true isolated dystonia, lead location was the most frequent problem., Conclusion: After exclusion of lead placement and stimulation programming issues, non-isolated dystonia, functional dystonia and fixed deformities account for the majority of GPi-DBS failures in dystonia., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The introduction of deep brain stimulation (DBS) about 25 years ago provided one of the major breakthroughs in the treatment of Parkinson's disease (PD). However, a high percentage of patients are reluctant to undergo DBS. Previous research revealed that the critical step on the patient's path to DBS is the decision whether to undergo further diagnostic assessment for surgery at a specialized DBS-center. The aims of the current study were to evaluate how effective the combination of an outpatient DBS screening tool, STIMULUS, with specially developed educational material was to enhance patient education on DBS and to identify motivational aspects which influenced the patients' willingness to undergo further assessment., Methods: In total, 264 patients were identified as appropriate candidates for DBS by general neurologists using the electronic preselection tool STIMULUS. Patient-centered information material was designed and handed out to support education on DBS. Further, several clinical characteristics and details of the patient counseling were documented. Refusal or consent to show up at a DBS center was registered over the following 16 months., Results: 114 (43.2%) patients preselected as eligible for DBS (STIMULUS Score ≥ 6) agreed to show up at a specialized DBS center to undergo further diagnostic assessment. The patients' ages, PD classification as an akinetic-rigid type and the talks' topics side-effects of dopaminergic medication and the optimal time frame had a significant influence on the patients' decisions., Conclusions: The combination of preselection tools as STIMULUS with comprehensive information material is effective to increase DBS-acceptance rate in PD patients. Important topics of the information about DBS cover the optimal time frame for DBS surgery, the side-effects of dopaminergic medication as well as side-effects and complications of DBS surgery.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) provides an effective treatment for Parkinson's disease (PD) motor symptoms. However, findings of effects on cognitive function such as feedback learning remain controversial and rare. The aim of the present study was to gain a better understanding of cognitive alterations associated with STN-DBS. Therefore, we investigated effects of STN-DBS on active and observational feedback learning in PD. 18 PD patients with STN-DBS and 18 matched healthy controls completed active and observational feedback learning tasks. Patients were investigated ON and OFF STN-DBS. Tasks consisted of learning (with feedback) and test phases (without feedback). STN-DBS improved active learning during feedback trials and PD patients ON (but not OFF) STN-DBS showed comparable performance patterns as healthy controls. No STN-DBS effect was found when assessing performance during active test trials without feedback. In this case, however, STN-DBS effects were found to depend on symptom severity. While more impaired patients benefited from STN-DBS, stimulation had no facilitating effect on patients with less severe symptoms. Along similar lines, the severity of motor symptoms tended to be significantly correlated with differences in active test performance due to STN-DBS. For observational feedback learning, there was a tendency for a positive STN-DBS effect with patients reaching the performance level of healthy controls only ON STN-DBS. The present data suggest that STN-DBS facilitates active feedback learning in PD patients. Furthermore, they provide first evidence that STN-DBS might not only affect learning from own but also from observed actions and outcomes., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: This study was conducted to better understand the development of clinical efficacy and impedance levels in the long-term course of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD)., Methods: In this retrospective study of twenty PD patients, the motor part of the Unified Parkinson's Disease Rating Scale was periodically assessed i) after withdrawal of medication and inactivated stimulation, ii) after withdrawal of medication with activated stimulation and iii) after challenge with l-Dopa during activated stimulation up to 13 years after surgery., Results: STN-DBS with or without medication significantly improved motor function up to 13 years after surgery. The contribution of axial symptoms increased over time. While the stimulation parameters were kept constant, the therapeutic impedances progressively declined., Conclusion: STN-DBS in PD remains effective in the long-term course of the disease. Constant current stimulation might be preferable over voltage-controlled stimulation, as it would alleviate the impact of impedance changes on the volume of tissue activated., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Pallidal deep brain stimulation (DBS) is effective in alleviating motor symptoms of medication refractory cervical dystonia, but little is known about effects on cognitive functions., Methods: As part of the first randomized, sham-controlled multicenter trial on DBS in medication-refractory primary cervical dystonia (ClinicalTrials.gov, number NCT00148889), a subgroup of 13 patients aged 39 to 69 underwent prospective neuropsychological long-term follow-up assessments. Various cognitive domains (memory, executive functions, attention, visual perception, mental arithmetic and verbal intelligence) were examined before and after 12 months of continuous DBS., Results: Only the number of produced words in a verbal fluency task which included alternating categories decreased after stimulation (p = 0.020). All other cognitive domains remained unchanged., Conclusions: These findings indicate that long-term pallidal DBS for the treatment of primary cervical dystonia seems to be safe regarding global cognitive functioning., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Cervical dystonia is managed mainly by repeated botulinum toxin injections. We aimed to establish whether pallidal neurostimulation could improve symptoms in patients not adequately responding to chemodenervation or oral drug treatment., Methods: In this randomised, sham-controlled trial, we recruited patients with cervical dystonia from centres in Germany, Norway, and Austria. Eligible patients (ie, those aged 18-75 years, disease duration ≥3 years, Toronto Western Spasmodic Torticollis Rating Scale [TWSTRS] severity score ≥15 points) were randomly assigned (1:1) to receive active neurostimulation (frequency 180 Hz; pulse width 120 μs; amplitude 0·5 V below adverse event threshold) or sham stimulation (amplitude 0 V) by computer-generated randomisation lists with randomly permuted block lengths stratified by centre. All patients, masked to treatment assignment, were implanted with a deep brain stimulation device and received their assigned treatment for 3 months. Neurostimulation was activated in the sham group at 3 months and outcomes were reassessed in all patients after 6 months of active treatment. Treating physicians were not masked. The primary endpoint was the change in the TWSTRS severity score from baseline to 3 months, assessed by two masked dystonia experts using standardised videos, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00148889., Findings: Between Jan 19, 2006, and May 29, 2008, we recruited 62 patients, of whom 32 were randomly assigned to neurostimulation and 30 to sham stimulation. Outcome data were recorded in 60 (97%) patients at 3 months and 56 (90%) patients at 6 months. At 3 months, the reduction in dystonia severity was significantly greater with neurostimulation (-5·1 points [SD 5·1], 95% CI -7·0 to -3·5) than with sham stimulation (-1·3 [2·4], -2·2 to -0·4, p=0·0024; mean between-group difference 3·8 points, 1·8 to 5·8) in the intention-to-treat population. Over the course of the study, 21 adverse events (five serious) were reported in 11 (34%) of 32 patients in the neurostimulation group compared with 20 (11 serious) in nine (30%) of 30 patients in the sham-stimulation group. Serious adverse events were typically related to the implant procedure or the implanted device, and 11 of 16 resolved without sequelae. Dysarthria (in four patients assigned to neurostimulation vs three patients assigned to sham stimulation), involuntary movements (ie, dyskinesia or worsening of dystonia; five vs one), and depression (one vs two) were the most common non-serious adverse events reported during the course of the study., Interpretation: Pallidal neurostimulation for 3 months is more effective than sham stimulation at reducing symptoms of cervical dystonia. Extended follow-up is needed to ascertain the magnitude and stability of chronic neurostimulation effects before this treatment can be recommended as routine for patients who are not responding to conventional medical therapy., Funding: Medtronic., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Expectation contributes to placebo and nocebo responses in Parkinson's disease (PD). While there is evidence for expectation-induced modulations of bradykinesia, little is known about the impact of expectation on resting tremor. Subthalamic nucleus (STN) deep brain stimulation (DBS) improves cardinal PD motor symptoms including tremor whereas impairment of verbal fluency (VF) has been observed as a potential side-effect. Here we investigated how expectation modulates the effect of STN-DBS on resting tremor and its interaction with VF. In a within-subject-design, expectation of 24 tremor-dominant PD patients regarding the impact of STN-DBS on motor symptoms was manipulated by verbal suggestions (positive [placebo], negative [nocebo], neutral [control]). Patients participated with (MedON) and without (MedOFF) antiparkinsonian medication. Resting tremor was recorded by accelerometry and bradykinesia of finger tapping and diadochokinesia were assessed by a 3D ultrasound motion detection system. VF was quantified by lexical and semantic tests. In a subgroup of patients, the effect of STN-DBS on tremor was modulated by expectation, i.e. tremor decreased (placebo response) or increased (nocebo response) by at least 10% as compared to the control condition while no significant effect was observed for the overall group. Interestingly, nocebo responders in MedON were additionally characterized by significant impairment in semantic verbal fluency. In contrast, bradykinesia was not affected by expectation. These results indicate that the therapeutic effect of STN-DBS on tremor can be modulated by expectation in a subgroup of patients and suggests that tremor is also among the parkinsonian symptoms responsive to placebo and nocebo interventions. While positive expectations enhanced the effect of STN-DBS by further decreasing the magnitude of tremor, negative expectations counteracted the therapeutic effect and at the same time exacerbated a side-effect often associated with STN-DBS. The present findings underscore the potency of patients' expectation and its relevance for therapeutic outcomes.

Expectation contributes to placebo and nocebo responses in Parkinson's disease (PD). Subthalamic nucleus (STN) deep brain stimulation (DBS) improves proximal more than distal movements whereas it impairs executive cognitive function such as verbal fluency (VF). We investigated how expectation modulates the pattern of motor improvement in STN-DBS and its interaction with VF. In a within-subject-design, expectation of 24 hypokinetic-rigid PD patients regarding the impact of STN-DBS on motor symptoms was manipulated by verbal suggestions (positive [placebo], negative [nocebo], neutral [control]). Patients participated with (MedON) and without (MedOFF) antiparkinsonian medication. Motor function was assessed by Unified Parkinson's Disease Rating Scale and quantitative kinematic analysis of proximal alternating hand and distal finger tapping. VF was quantified by lexical and semantic tests. In MedOFF, expectation significantly affected proximal but not distal movements resulting in better performance in the placebo than in the nocebo condition. Placebo responders with improvement of ≥25% were characterized by a trend for impaired lexical VF. These results indicate that positive motor expectations exert both motor placebo and cognitive nocebo responses by further enhancing the STN-DBS-effect on proximal movements and by impairing VF. The placebo response on motor performance resembles the clinically known STN-DBS-effect with stronger improvement in proximal than distal movements. The nocebo response on VF is likely due to implicit learning mechanisms associated with an expectation-induced placebo response on motor performance., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Background: The aim of this questionnaire-based study was to determine the decision-making motives from Parkinson's patients and their family members for deep brain stimulation (DBS), which are crucial for the attitude towards this therapy and which should be considered during the clinical interview., Material and Methods: The questionnaire was sent out nationwide to members of the German Parkinson Association. Patient and family specific data as well as information sources, doubts and expectations with respect to DBS were assessed., Results: A total of 582 patients and 476 family members answered the questionnaire, revealing that 96% of the patients and 91% of the family members already possessed information regarding DBS. While a large proportion of interviewees had specific expectations concerning DBS, more than two thirds expressed concerns regarding DBS; the most frequent with respect to intraoperative complications and stimulation-induced worsening of symptoms. The quantity of realistic patients and family expectations significantly correlated with a positive evaluation of DBS and doubts as well as unrealistic expectations of family members correlated with a negative attitude towards the operation., Conclusions: The findings suggest that patients and their relatives organized in support groups indeed possess detailed information regarding DBS. However, for the acceptance of the treatment a timely elucidation about DBS as well as responding to the individual concerns by the consulting physician is essential.

The mechanism and time course of emotional side effects of subthalamic deep brain stimulation in Parkinson's disease are a matter for discussion. We report a 53-month follow-up of a patient with affective lability. Postoperative lesion plus bilateral stimulation strongly influenced mood in the first week in terms of laughing behavior, while voltage changes had only minor long-term impact up to 37 months on negative emotion, possibly caused by the right electrode stimulating the subthalamic nucleus and adjacent fiber tracts involving the internal capsule. Thus we conclude that affective lability can occur with different temporal dynamics of microlesion, and early and chronic stimulation.

Timing in the range of seconds referred to as interval timing is crucial for cognitive operations and conscious time processing. According to recent models of interval timing basal ganglia (BG) oscillatory loops are involved in time interval recognition. Parkinsońs disease (PD) is a typical disease of the basal ganglia that shows distortions in interval timing. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a powerful treatment of PD which modulates motor and cognitive functions depending on stimulation frequency by affecting subcortical-cortical oscillatory loops. Thus, for the understanding of BG-involvement in interval timing it is of interest whether STN-DBS can modulate timing in a frequency dependent manner by interference with oscillatory time recognition processes. We examined production and reproduction of 5 and 15 second intervals and millisecond timing in a double blind, randomised, within-subject repeated-measures design of 12 PD-patients applying no, 10-Hz- and ≥ 130-Hz-STN-DBS compared to healthy controls. We found under(re-)production of the 15-second interval and a significant enhancement of this under(re-)production by 10-Hz-stimulation compared to no stimulation, ≥ 130-Hz-STN-DBS and controls. Milliseconds timing was not affected. We provide first evidence for a frequency-specific modulatory effect of STN-DBS on interval timing. Our results corroborate the involvement of BG in general and of the STN in particular in the cognitive representation of time intervals in the range of multiple seconds.

Cardinal symptoms of Parkinson's disease (PD) respond well to treatment with levodopa and deep brain stimulation (DBS) of the subthalamic nucleus (STN). However, it has remained unclear whether levodopa and STN-DBS have differential effects on bradykinesia. We investigated 8 PD-patients with STN-electrodes in four conditions: STN-DBS and levodopa (ON(MED)/ON(STIM)), STN-DBS only (OFF(MED)/ON(STIM)), levodopa only (ON(MED)/OFF(STIM)), without STN-DBS/levodopa (OFF(MED)/OFF(STIM)). Fourteen volunteers served as controls. Subjects performed fastest possible (1) pronation/supination of the forearm (diadochokinesia) and (2) flexion and extension of the index finger (finger movements). Movements were recorded using a 3D-ultrasound-system. Maximum frequency, amplitude, and smoothness of movements were determined. During OFF(MED)/OFF(STIM), all parameters were worser than in all other conditions. In proximal diadochokinesia, OFF(MED)/ON(STIM) significantly improved the amplitude and frequency, whereas ON(MED)/OFF(STIM) had no significant effect. In contrast, we found a stronger effect of levodopa (ON(MED)/OFF(STIM)) on amplitudes of distal finger movement than on amplitudes of diadochokinesia. Combination of treatments during ON(MED)/ON(STIM) further improved both movements. However, maximum frequency remained lower in PD-patients during ON(MED)/ON(STIM) compared with controls. This study demonstrates a better effect of levodopa on distal finger movements and STN-DBS on proximal diadochokinesia. Furthermore, a complementary effect of both therapies on brain areas involved in bradykinesia can be assumed., (2007 Movement Disorder Society)

Pathological crying (PLC)--an affective gesture without any or an adequate emotion--occurs with various diseases. A recent theory suggests that PLC is caused by a disruption of higher order cortical association areas from the cerebellum which computes profiles of psychomotor responses. We report a patient with Parkinson's disease who developed PLC during stimulation of the subthalamic nucleus (STN) predominantly of the right hemisphere. Positron emission tomography imaging showed thalamo-ponto-cerebellar activation during such stimulation. These findings indicate that the STN and possibly also ponto-cerebellar pathways are involved in psychomotor control and in the modulation of PLC., (2007 Movement Disorder Society)

Background: High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor functions in those with Parkinson disease but may worsen frontal functions such as verbal fluency (VF). In contrast, low-frequency DBS leads to deterioration of motor functions. It is not known whether low-frequency STN DBS also has an effect on frontal functions., Objective: To examine whether low-frequency STN DBS in contrast to high-frequency STN DBS has a positive effect on frontal functions on the basis of VF test results., Design: A double-blind randomized crossover experiment to compare performance in 4 VF subtests and motor performance at 10 Hz, 130 Hz, and no stimulation., Setting: University hospitals in Düsseldorf and Cologne, Germany., Patients: Twelve patients with Parkinson disease 3 months or more after bilateral electrode implantation into the STN., Main Outcome Measure: Mean number of words in VF at different stimulation frequencies., Results: The VF was significantly better at 10 Hz (48.3 words) compared with 130 Hz and showed a nonsignificant trend toward worsening at 130 Hz (42.3 words) compared with no stimulation (43.8 words). These results were consistent across all subtests., Conclusions: The study provides evidence of a beneficial effect of low-frequency (10 Hz) STN DBS on VF, which may be caused by activating neural pathways projecting to the frontal cortex. In addition, the study reproduces the negative effect of therapeutic high-frequency STN DBS on VF. The study results provide evidence for a frequency-dependent modulation of cognitive circuits involving the STN.

During the last 15 years deep brain stimulation (DBS) has been established as a highly-effective therapy for advanced Parkinson’s disease (PD). Patient selection, stereotactic implantation, postoperative stimulator programming and patient care requires a multi-disciplinary team including movement disorders specialists in neurology and functional neurosurgery. To treat medically refractory levodopa-induced motor complications or resistant tremor the preferred target for high-frequency DBS is the subthalamic nucleus (STN). STN-DBS results in significant reduction of dyskinesias and dopaminergic medication, improvement of all cardinal motor symptoms with sustained long-term benefits, and significant improvement of quality of life when compared with best medical treatment. These benefits have to be weighed against potential surgery-related adverse events, device-related complications, and stimulus-induced side effects. The mean disease duration before initiating DBS in PD is currently about 13 years. It is presently investigated whether the optimal timing for implantation may be at an earlier disease-stage to prevent psychosocial decline and to maintain quality of life for a longer period of time. [ABSTRACT FROM PUBLISHER]

Decisions about how to respond optimally in daily life are often guided by learning from consequences of chosen actions. Response-outcome associations can be learned by active responding to a stimulus or by observing responses and associated consequences in others. There is evidence that, depending on medication status, patients with Parkinson’s disease (PD) are relatively impaired in tasks requiring active learning from feedback. Regarding subthalamic nucleus (STN) deep brain stimulation (DBS), an increasingly utilized and highly effective treatment option for PD-symptoms, effects on learning are less clear. There are first indications of enhanced active feedback learning with STN stimulation due to a suggested modulatory effect of STN-DBS on the dorsal striatum, which is involved in linking own actions and outcomes. The aim of the present investigation was to compare the effect of DBS on active and observational feedback learning in patients with PD. Since learning by observation may depend less on the dorsal striatum, we hypothesized that STN stimulation affects learning of associations during active but not observational feedback learning. Twenty PD patients with STN-DBS and 20 age-matched controls performed active and observational feedback learning tasks. PD patients, remaining on their regular dopaminergic medication, completed both tasks ON and OFF-stimulation. During the active learning task, subjects had to respond to abstract visual stimuli with either the left or the right hand by button press. After each response, they received positive or negative feedback. During the observational learning task, subjects observed responses and accompanying outcomes of another person. Test phases consisting of trials without feedback served to assess learning of stimulus–response-outcome associations. We will present preliminary results regarding the effects of STN-DBS on observational and active feedback learning in PD patients. The findings will be discussed in light of the need to further understand not only motor but also cognitive effects of DBS in PD patients. [ABSTRACT FROM AUTHOR]

Question Deep Brain stimulation (DBS) is a widely established, effective and well-tolerated treatment for Parkinson’s disease (PD). The patients’ way to receive this treatment usually consists of two steps: first, general neurologists refer them to a specialized DBS center where they undergo further diagnostic assessment and the final decision for or against this treatment is made. Electronic tools are available to support general neurologists in the selection of DBS candidates. Nevertheless, even after being preselected as an appropriate candidate, the majority of patients refused to be referred to a DBS center (Wächter et al., J Neurol 2011;258:641–646). Patients and methods Two projects were initiated to increase the treatment acceptance of DBS for PD: (A) A collaboration of 20 general neurologists and two movement disorder specialists at the University Hospital Düsseldorf was established. (B) 51 general neurologists located all over Germany were trained to use the electronic preselection tool STIMULUS and were handed out newly developed information materials. In both projects, appropriate DBS candidates were preselected. Their acceptance or refusal to undergo further diagnostic assessment at a DBS center was documented within a 16 months follow-up period. Further, several clinical characteristics and details of the patient briefing were collected and analyzed to identify factors which were predictive for patients’ decisions. Results (A) 912 PD patients were examined by the movement disorder specialist together with the general neurologist. In 92 cases (10.1%), a referral to undergo further diagnostic assessment at the University Hospital Düsseldorf was recommended. Within 16 months, 69 (70.4%) of those patients showed up in the specialized DBS center. (B) 264 patients were identified as appropriate candidates for DBS, using the electronic preselection tool STIMULUS and 114 (43.2%) had accepted to be referred to a DBS center within a 16 month follow-up period. The patients’ decisions were significantly influenced by their age, their classification as an akinetic-rigid type and when mentioning a potential reduction of dopaminergic side effects as well as the optimal time frame for DBS during the clarification talk. Conclusion Consultation visits by movement disorder specialists in collaboration with general neurologists substantially improved the treatment acceptance of PD patients for DBS. A training of general neurologists in combination with adequate information material might be a low-cost and effective alternative option. Both findings indicate the importance of a clarification talk to be crucial in order to increase the treatment acceptance for DBS. This assumption is supported by the talks’ topics side effects of dopaminergic medication and optimal time frame which were significantly related to a higher rate of acceptance if mentioned. [ABSTRACT FROM AUTHOR]