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© 2023 European Academy of Neurology, Hariz and colleagues [1] argue that the new EAN/MDS GL contradicts the repeated endorsements of pallidotomy by the MDS. The MDS has previously published “evidence based medicine (EBM) reviews,” which appraise each treatment on the basis of welldefined criteria but are not GLs. Clinical GLs, such as the new EAN/MDS GL, also take into consideration other variables, including context, summarizing the current medical knowledge, weighing the benefits and harms of treatments, and giving specific recommendations based on this information. The specific GRADE GL methodology allows for the evaluation of available scientific evidence with a sophisticated evaluation process that includes grading the strength of the evidence and the certainty of that evidence, out of which the recommendations are developed. These steps are well documented in our appendices 1 and 2 for methodology and appendices 3 and 4 for outcomes. Thus, the case of radiofrequency pallidotomy and deep brain stimulation (DBS) of the pallidum, which is discussed by Hariz et al, illustrates the difference between EBM reviews and GLs. The EBM review ranks pallidotomy at the same level as globus pallidus internus (GPi)-DBS: both treatments are considered “efficacious,” “clinically useful,” and coming with a “clinically acceptable risk with specialized monitoring,” but it does not express whether the treatments are equal in their application in patients overall. In our GL using the GRADE methodology, in contrast, GPi-DBS is recommended, whereas pallidotomy is recommended only with restrictions.

[Background and Purpose] This update of the treatment guidelines was commissioned by the European Academy of Neurology and the European section of the Movement Disorder Society. Although these treatments are initiated usually in specialized centers, the general neurologist and general practitioners taking care of PD patients should know the therapies and their place in the treatment pathway., [Methods] Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used to assess the spectrum of approved interventions including deep brain stimulation (DBS) or brain lesioning with different techniques (radiofrequency thermocoagulation, radiosurgery, magnetic resonance imaging–guided focused ultrasound surgery [MRgFUS] of the following targets: subthalamic nucleus [STN], ventrolateral thalamus, and pallidum internum [GPi]). Continuous delivery of medication subcutaneously (apomorphine pump) or through percutaneous ileostomy (intrajejunal levodopa/carbidopa pump [LCIG]) was also included. Changes in motor features, health-related quality of life (QoL), adverse effects, and further outcome parameters were evaluated. Recommendations were based on high-class evidence and graded in three gradations. If only lower class evidence was available but the topic was felt to be of high importance, clinical consensus of the guideline task force was gathered., [Results] Two research questions have been answered with eight recommendations and five clinical consensus statements. Invasive therapies are reserved for specific patient groups and clinical situations mostly in the advanced stage of Parkinson's disease (PD). Interventions may be considered only for special patient profiles, which are mentioned in the text. Therapy effects are reported as change compared with current medical treatment. STN-DBS is the best-studied intervention for advanced PD with fluctuations not satisfactorily controlled with oral medications; it improves motor symptoms and QoL, and treatment should be offered to eligible patients. GPi-DBS can also be offered. For early PD with early fluctuations, STN-DBS is likely to improve motor symptoms, and QoL and can be offered. DBS should not be offered to people with early PD without fluctuations. LCIG and an apomorphine pump can be considered for advanced PD with fluctuations not sufficiently managed with oral treatments. Unilateral MRgFUS of the STN can be considered for distinctly unilateral PD within registries. Clinical consensus was reached for the following statements: Radiosurgery with gamma radiation cannot be recommended, unilateral radiofrequency thermocoagulation of the pallidum for advanced PD with treatment-resistant fluctuations and unilateral radiofrequency thermocoagulation of the thalamus for resistant tremor can be recommended if other options are not available, unilateral MRgFUS of the thalamus for medication-resistant tremor of PD can be considered only within registries, and unilateral MRgFUS of the pallidum is not recommended., [Conclusions] Evidence for invasive therapies in PD is heterogeneous. Only some of these therapies have a strong scientific basis. They differ in their profile of effects and have been tested only for specific patient groups., The GL development was further supported by travel grants for meetings and support for online meetings by EAN/MDS-ES. Katarzyna Śmiłowska was supported with a stipend of the Medical Faculty of the Christian-Albrechts-University, Kiel. Open Access funding enabled and organized by Projekt DEAL. Mir has received grants from the Spanish Ministry of Science and Innovation, the Instituto de Salud Carlos III-Fondo Europeo de Desarrollo Regional, the Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía, and the Consejería de Salud y Bienestar Social de la Junta de Andalucía. A. Schrag has received grants from GE Healthcare.

International audience; Background and purpose: Studies on long-term nonmotor outcomes of subthalamic nucleus stimulation in Parkinson disease (PD) are scarce. This study reports on very long-term non-motor and motor outcomes in one of the largest cohorts of people with advanced PD, treated for >10 years with subthalamic nucleus stimulation. The main outcome was to document the evolution of independence in activities of daily living. The secondary outcomes were to measure the change in quality of life, as well as non-motor and motor outcomes.Methods: Patients were studied preoperatively, at 1 year, and beyond 10 years after subthalamic stimulation with an established protocol including motor, non-motor, and neuropsychological assessments.Results: Eighty-five people with PD were included. Independence scores in the off-medication condition (measured with the Schwab & England Activities of Daily Living Scale) as well as quality of life (measured with the Parkinson's Disease Questionnaire [PDQ]-37) remained improved at longest follow-up compared to preoperatively (respectively, p < 0.001, p = 0.015). Cognitive scores, measured with the Mattis Dementia Rating Scale, significantly worsened compared to before and 1 year after surgery (p < 0.001), without significant change in depression, measured with the Beck Depression Inventory. Motor fluctuations, dyskinesias, and off dystonia remained improved at longest follow-up (p < 0.001), with a significant reduction in dopaminergic treatment (45%, p < 0.001).Conclusions: This study highlights the long-term improvement of subthalamic stimulation on independence and quality of life, despite the progression of disease and the occurrence of levodopa-resistant symptoms.

We report the case of a 77-year-old man with Parkinson's disease (PD) who experimented for the first time gout crisis after the initiation of levodopa. Levodopa was withdrawn, and colchicine and allopurinol were initiated to treat the gout crisis. Because of PD progression, levodopa was reintroduced, and the patient presented relapse of gout flare. To further explore the association between gout and levodopa, we extracted and synthetized all Individual Case Safety Reports of gout associated with levodopa in the World Health Organization pharmacovigilance database, VigiBase® , up to April 2021. 43 cases of gout were reported in VigiBase® with drugs from N04BA ATC class. Levodopa was suspected in fifteen cases among which improvement was noticed in six cases (two after levodopa withdrawal, two despite treatment continuation, and two cases lacking details about action taken with levodopa); three cases did not recover; in the remaining six cases, evolution was not known. "Hyperuricemia" was not mentioned in the Summary of Product Characteristics of medicine containing levodopa; however, "abnormality biologics test with uric acid" was mentioned. Despite few cases of recovery after reduced doses of levodopa, the above-described case of positive reintroduction was an argument in favor of the role of levodopa in gout flare. This study highlights a potential association between levodopa and gout through an analysis of the cases reported in the WHO pharmacovigilance database.

Objective The dual hit hypothesis about the pathogenesis of Parkinson disease (PD) suggests that the brainstem is a convergent area for the propagation of pathological α-synuclein from the periphery to the brain. Although brainstem structures are likely to be affected early in the course of the disease, detailed information regarding specific brainstem regions is lacking. The aim of our study was to investigate the function of the superior colliculus, a sensorimotor brainstem structure, in de novo PD patients compared to controls using brain functional magnetic imaging and visual stimulation paradigms. Methods De novo PD patients and controls were recruited. PD subjects were imaged before and after starting PD medications. A recently developed functional magnetic resonance imaging protocol was used to stimulate and visualize the superior colliculus and 2 other visual structures: the lateral geniculate nucleus and the primary visual cortex. Results In the 22 PD patients, there was no modulation of the superior colliculus responses to the luminance contrasts compared to controls. This implies a hypersensitivity to low luminance contrast and abnormal rapid blood oxygenation level-dependent signal saturation to high luminance contrasts. The lateral geniculate nucleus was only modulated by 3 to 9% luminance contrasts compared to controls. No major differences were found in the primary visual cortex between both groups. Interpretation Our findings suggest that pathological superior colliculus visual responses in de novo PD patients are present early in the course of the disease. Changes in imaging the superior colliculus could play an important role as a preclinical biomarker of the disease. ANN NEUROL 2020;87:533-546.

Coronavirus disease 2019 (COVID‐19), a multi‐organ disease caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), continues to challenge health and care systems around the globe. The pandemic has disrupted acute neurology services and routine patient care and has impacted the clinical course in patients with chronic neurological disease. COVID‐19 appears to have exposed inequalities of societies and healthcare systems and had a disproportionate impact on already vulnerable communities. The next challenge will be to set up initiatives to stop disparities in all aspects related to COVID‐19. From the medical perspective, there is a need to consider inequalities in prevention, treatment and long‐term consequences. Some of the issues of direct relevance to neurologists are summarised. With this appraisal, the European Academy of Neurology NeuroCOVID‐19 Task Force intends to raise awareness of the potential impact of COVID‐19 on inequalities in healthcare and calls for action to prevent disparity at individual, national and supranational levels.

Immunization by means of vaccination is a global health success story, saving millions of lives every year. In this regard, the epidemiology of measles, rabies, polio, rubella, varicella, influenza and mumps infections, all of which can harm the nervous system, could be contained by global vaccination campaigns. In addition, toxoid vaccines against bacterial toxins such as tetanus and diphtheria are indispensable and effective interventions for toxin-mediated neurologic diseases.

Background and purpose: Although the main clinical features of COVID-19 infection are pulmonary, several associated neurological signs, symptoms and diseases are emerging. The incidence and characteristics of neurological complications are unclear. For this reason, the European Academy of Neurology (EAN) core COVID-19 Task Force initiated a survey on neurological symptoms observed in patients with COVID-19 infection. Methods: A 17-question online survey was made available on the EAN website and distributed to EAN members and other worldwide physicians starting on 9 April 2020. Results: By 27 April 2020, proper data were collected from 2343 responders (out of 4199), of whom 82.0% were neurologists, mostly from Europe. Most responders (74.7%) consulted patients with COVID-19 mainly in emergency rooms and in COVID-19 units. The majority (67.0%) had evaluated fewer than 10 patients with neurological manifestations of COVID-19 (neuro COVID-19). The most frequently reported neurological findings were headache (61.9%), myalgia (50.4%), anosmia (49.2%), ageusia (39.8%), impaired consciousness (29.3%) and psychomotor agitation (26.7%). Encephalopathy and acute cerebrovascular disorders were reported at 21.0%. Neurological manifestations were generally interpreted as being possibly related to COVID-19; they were most commonly recognized in patients with multiple general symptoms and occurred at any time during infection. Conclusion: Neurologists are currently and actively involved in the management of neurological issues related to the COVID-19 pandemic. This survey justifies setting up a prospective registry to better capture the prevalence of patients with neuro COVID-19, neurological disease characteristics and the contribution of neurological manifestations to outcome. info:eu-repo/semantics/publishedVersion

Background Non-motor fluctuations represent a main source of disability in Parkinson's disease (PD). Among them, neuropsychiatric fluctuations are the most frequent and are often under-recognized by patients and physicians, partly because specific tools for assessment of neuropsychiatric fluctuations are lacking. Objective To develop a scale for detecting and evaluating the presence and the severity of neuropsychological symptoms during the ON and OFF phases of non-motor fluctuations. Methods Neuropsychiatric symptoms reported by PD patients in the OFF- and the ON-medication conditions were collected using different neuropsychiatric scales (BDI-II, BAI, Young, VAS, etc.). Subsequently, tree phases of a pilot study was performed for cognitive pretesting, identification of ambiguous or redundant items (item reduction), and to obtain preliminary data of acceptability of the new scale. In all the three phases, the scale was applied in both the OFF and ON condition during a levodopa challenge. Results Twenty items were selected for the final version of the neuropsychiatric fluctuation scale (NFS): ten items measured the ON neuropsychological symptoms and ten items the OFF neuropsychological manifestations. Each item rated from 0-3, providing respective subscores from 0 to 30. Conclusions Once validated, our NFS can be used to identify and quantify neuropsychiatric fluctuations during motor fluctuations. The main novelty is that it could be used in acute settings. As such, the NFS can assess the neuropsychiatric state of the patient at the time of examination. The next step will be to validate the NFS to be used in current practice.

Advanced Parkinson's disease is characterized by the presence of motor fluctuations, various degree of dyskinesia, and disability with functional impact on activities of daily living and independence. Therapeutic management aims to extend levodopa benefit while minimizing motor complications and includes, in selected cases, the implementation of drug infusion and surgical techniques. In milder forms of motor complications, these can often be controlled with manipulation of levodopa dose and the introduction of supplemental therapies such as catechol-O-methyl transferase inhibitors, monoamine oxidase B inhibitors, and dopamine agonists including apomorphine. Clinical experience and evidence from published studies indicate that when these agents cannot satisfactorily control motor complications, patients should be assessed and considered for device-aided therapies. This review article summarizes some of the newer available therapeutic opportunities such as use of enzyme inhibitors like opicapone and safinamide, adenosine A2A receptor antagonists, apomorphine and levodopa/carbidopa intestinal gel infusion, deep brain stimulation including the role of closed-loop and adaptive stimulation, and MRI-guided focused ultrasound. © 2018 International Parkinson and Movement Disorder Society.

Objective Internal globus pallidus (GPi) deep brain stimulation (DBS) relieves symptoms in dystonia patients. However, the physiological effects produced by GPi DBS are not fully understood. In particular, how a single-pulse GPi DBS changes cortical circuits has never been investigated. We studied the modulation of motor cortical excitability and plasticity with single-pulse GPi DBS in dystonia patients with bilateral implantation of GPi DBS. Methods The cortical evoked potentials from DBS were recorded with electroencephalography. Transcranial magnetic stimulation with a conditioning test paired-pulse paradigm was used to investigate the effect of GPi DBS on the primary motor cortex. How GPi DBS might modulate the motor cortical plasticity was tested using a paired associative stimulation paradigm with repetitive pairs of GPi DBS and motor cortical stimulation at specific time intervals. Results GPi stimulation produced 2 peaks of cortical evoked potentials with latencies of ∼10 and ∼25 milliseconds in the motor cortical area. Cortical facilitation was observed at ∼10 milliseconds after single-pulse GPi DBS, and cortical inhibition was observed after a ∼25-millisecond interval. Repetitive pairs of GPi stimulation with cortical stimulation at these 2 time intervals produced long-term potentiation-like effects in the motor cortex. Interpretation Single-pulse DBS modulates cortical excitability and plasticity at specific time intervals. These effects may be related to the mechanism of action of DBS. Combination of DBS with cortical stimulation with appropriate timing has therapeutic potential and could be explored in the future as a method to enhance the effects of neuromodulation for neurological and psychiatric diseases. Ann Neurol 2018;83:352-362.

Pedunculopontine nucleus region deep brain stimulation (DBS) is a promising but experimental therapy for axial motor deficits in Parkinson's disease (PD), particularly gait freezing and falls. Here, we summarise the clinical application and outcomes reported during the past 10 years. The published dataset is limited, comprising fewer than 100 cases. Furthermore, there is great variability in clinical methodology between and within surgical centers. The most common indication has been severe medication refractory gait freezing (often associated with postural instability). Some patients received lone pedunculopontine nucleus DBS (unilateral or bilateral) and some received costimulation of the subthalamic nucleus or internal pallidum. Both rostral and caudal pedunculopontine nucleus subregions have been targeted. However, the spread of stimulation and variance in targeting means that neighboring brain stem regions may be implicated in any response. Low stimulation frequencies are typically employed (20-80 Hertz). The fluctuating nature of gait freezing can confound programming and outcome assessments. Although firm conclusions cannot be drawn on therapeutic efficacy, the literature suggests that medication refractory gait freezing and falls can improve. The impact on postural instability is unclear. Most groups report a lack of benefit on gait or limb akinesia or dopaminergic medication requirements. The key question is whether pedunculopontine nucleus DBS can improve quality of life in PD. So far, the evidence supporting such an effect is minimal. Development of pedunculopontine nucleus DBS to become a reliable, established therapy would likely require a collaborative effort between experienced centres to clarify biomarkers predictive of response and the optimal clinical methodology. © 2017 International Parkinson and Movement Disorder Society.

Acceptance of case reports in the European Journal of Neurology is extremely limited, and only reports that make a major clinico-pathological or educational contribution or suggest a significant change of diagnosis or therapy will be accepted. We have decided that we will not publish single cases (or small descriptive series) of neurological disorders occurring after vaccination against SARS-COV2 infection.

Background Pallidal deep brain stimulation (GPi-DBS) effectively ameliorates idiopathic dystonia, although approximately 15% of patients respond insufficiently. Although various thalamic and subthalamic targets have been suggested for dystonic tremor, no systematic studies have been published on thalamic DBS in dystonic tremor. We assessed the effect of thalamic/subthalamic area DBS (Th-DBS) on dystonic head tremor and dystonia in a single-blind design. Methods Dystonic head tremor and dystonia before and 3 months after surgery were quantified via blinded video-ratings using the Fahn-Tolosa-Marin-Tremor-Scale and the Burke-Fahn-Marsden-Dystonia-Rating-Scale in seven patients with idiopathic cervical or segmental dystonia, dystonic head tremor, and bilateral Th-DBS. Pain, side effects, adverse events, and stimulation parameters were assessed. Results Th-DBS improved dystonic tremor and dystonia (P

Background Improvement after bilateral globus pallidus internus deep brain stimulation (DBS) in primary generalized dystonia has been negatively associated with disease duration and age, but no predictive factors have been identified in primary cervical dystonia (CD). Methods Patients treated with bilateral globus pallidus internus DBS for primary CD from 2 DBS centers with preoperative and postoperative Toronto Western Spasmodic Torticollis Rating Scales (TWSTRS) were studied retrospectively to explore possible predictors of response. Results Patients showed significantly improved TWSTRS total and severity scores (n = 28, mean 55.6% and 50.8%, respectively, both P

It is now established that pallidal deep brain stimulation (DBS) is effective in the treatment of generalized and segmental primary dystonia, although there is still insufficient evidence to support its benefit in focal and secondary dystonia. Because several studies have demonstrated that pallidal DBS improves quality of life (QoL), reduced QoL and disability that are nonresponsive to medical treatment are probably the main factors guiding the decision to consider surgery. Some studies have indicated that young patients with primary dystonia who have shorter disease duration and less severe dystonia are likely to have the best outcome from DBS. Therefore, surgery should not be delayed when disability and QoL are impaired to the extent that justifies the surgical risk. A case-by-case approach is recommended in patients who have secondary dystonia. The globus pallidus internus is considered the best target for dystonia. There are still not enough data about the effectiveness of thalamic, subthalamic nucleus, and premotor cortex stimulation. Targeting with multiple electrodes and intra-individual comparisons of outcomes may help determine which target would be more beneficial. With regard to the role of lesions, pallidotomy for dystonia is still performed in several countries and can play a role in selected patients. New technologies are already available to improve the stimulation programming for DBS patients and to increase battery longevity. In the near future, it is possible that we will be able to shape stimulation settings according to disease type and symptoms. © 2013 Movement Disorder Society.

Background: To report on the clinical efficacy of bilateral globus pallidus internus deep brain stimulation in a 29-year-old patient with severe generalized dystonia secondary to Wilson’s disease. Methods: The primary outcome measure was the BurkeFahn-Marsden Dystonia Scale motor severity score (blinded assessment) and the secondary outcome measures were the Abnormal Involuntary Movement Scale (blinded assessment) and the Zaritt Caregiver Burden Interview score, at 20-week postoperative follow up. Results: There was a 14% improvement in the BurkeFahn-Marsden Dystonia Scale motor severity score. Abnormal Involuntary Movement Scale score remained unchanged while the Zaritt Caregiver Burden Interview score improved by 44.4%. Conclusions: Bilateralglobuspallidusdeepbrainstimulation can be effective in ameliorating dystonia and caregiver burden in Wilson s disease. Outcomes may depend on the stage of the disease at which the surgical procedureiscompleted. V C 2013MovementDisorderSociety

The surgical lesion of different brain structures has been used as a treatment for Parkinson's disease (PD) for several decades. More recently, the favored therapeutic approach has involved the administration of levodopa and the use of DBS. These two major therapeutic advances have greatly modified both the clinical condition of patients and the history of the disease. With the introduction of L-dopa in 1967, patients could regain mobility, because their akinesia, tremor, and rigidity were greatly improved, with consequent significant improvement in quality of life and increased life expectancy. However, after the so-called “honeymoon” period in which the disease seemed to be controlled, motor fluctuations and L-dopa-induced dyskinesias mitigated the initial enthusiasm. In the 1990s, unilateral pallidotomy and DBS of the globus palllidus internus and STN reduced these motor fluctuations and dyskinesias remarkably, thereby inaugurating a new era in the surgical treatment of PD. Short- and medium-term follow-up studies of patients who underwent surgery have documented sustained, significant motor benefits. However, given the progressive nature of PD and the purely symptomatic effects of pallidotomy and DBS, the long-term clinical evolution of these surgical patients currently seems to be associated with a new PD phenotype, mainly characterized by axial motor problems and cognitive impairment. Here, we analyze the long-term clinical outcomes of surgical PD patients with at least 5-year follow-up, focusing on the long-term motor symptoms that were initially responsive to surgery. © 2012 Movement Disorder Society

Background: Pedunculopontine nucleus (PPN) DBS has emerged as a potential intervention for patients with gait and balance disorders. However, targeting this nucleus can be challenging. We report on the first neuropathological analyses after PPN-DBS surgery in advanced progressive supranuclear palsy (PSP). Methods: Two patients with PSP underwent unilateral PPN-DBS surgery and were clinically followed to autopsy. Both patients underwent postmortem neuropathological analysis, including choline acetyltransferase immunohistochemistry, to ascertain PPN boundaries and electrode location. Results: Both patients experienced partial improvement in some motor and nonmotor domains postintervention, but died shortly of other complications. Postmortem neuropathological analysis of each patient confirmed the electrode in a region of cholinergic neuronal loss corresponding to the PPN. Conclusions: We provide histopathological evidence for the validity of our stereotactic approach to target the PPN and correlate electrode location with clinical outcomes. © 2012 Movement Disorder Society

The pedunculopontine nucleus region (PPNR) is an integral component of the midbrain locomotor region and has widespread connections with the cortex, thalamus, brain stem, cerebellum, spinal cord, and especially, the basal ganglia. No previous study examined the somatosensory connection of the PPNR in human. We recorded somatosensory evoked potentials (SEP) from median nerve stimulation through deep brain stimulation (DBS) electrodes implanted in the PPNR in 8 patients (6 with Parkinson's disease, 2 with progressive supranuclear palsy). Monopolar recordings from the PPNR contacts showed triphasic or biphasic potentials. The latency of the largest negative peak was between 16.8 and 18.7 milliseconds. Bipolar derivation revealed phase reversal with median nerve stimulation contralateral to the DBS electrode in 6 patients. There was no difference in SEP amplitude and latency between on and off medication states. We also studied the high frequency oscillations (HFOs) by filtering the signal between 500 and 2,500 Hz. The HFOs could be identified only from contralateral stimulation and had intraburst frequencies of 1061 ± 121 Hz, onset latencies of 13.8 ± 1.2 milliseconds, and burst durations of 7.3 ± 1.1 milliseconds. Among the 10 recordings with HFOs, only 1 had possible phase reversal in the bipolar derivation. Our results suggest that there are direct somatosensory inputs to the PPNR. The slow components and HFOs of the SEP have different origins.

Chorea-acanthocytosis is a rare autosomal recessive neurodegenerative disorder with a complex clinical presentation comprising of a mixed movement disorder (mostly chorea and dystonia), seizures, neuropathy and myopathy, autonomic features as well as dementia and psychiatric features. Because the differential diagnosis is wide, clinical clues and red flags are important. We report here our observation of characteristic neck and trunk flexion and extension spasms in four cases with advanced chorea-acanthocytosis.

We report the 5 to 6 year follow-up of a multicenter study of bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) in advanced Parkinson's disease (PD) patients. Thirty-live STN patients and 16 GPi patienis were assessed at 5 to 6 years after DBS surgery. Primary outcome measure was the stimulation effect on the motor Unified Parkinson's Disease Rating Scale (UPDRS) assessed with a prospective cross-over double-blind assessment without medications (stimulation was randomly switched on or off). Secondary outcomes were motor UPDRS changes with unblinded assessments in off- and on-medication states with and without stimulation, activities of daily living (ADL), anti-PD medications, and dyskinesias. In double-blind assessment, both STN and GPi DBS were significantly effective in improving the motor UPDRS scores (STN. P < 0.0001, 45.4%; GPi, P = 0.008, 20.0%) compared with of regardless of the sequence of stimulation. In open assessment. both STN- and GPi-DBS significantly improved the off-medication motor UPDRS when compared with before surgery (STN. P < 0.001, 50.5%; GPi, P = 0.002, 35.6%). Dyskinesias and ADL were significantly improved in both groups. Anti-PD medications were significantly reduced only in the STN group. Adverse events were more frequent in the STN group. These results confirm the long-term efficacy of STN and GPi DBS advanced PD. Although the surgical targets were not randomized, there was a trend to 1 better outcome of motor signs in the STN-DBS patients and fewer adverse events in the GPi-DBS group. (C) 2010 Movement Disorder Society

International audience; Objective: In Parkinson disease (PD) patients, deep brain stimulation (DBS) of the subthalamic nucleus (STN) may contribute to certain impulsive behavior during high-conflict decisions. A neurocomputational model of the basal ganglia has recently been proposed that suggests this behavioral aspect may be related to the role played by the STN in relaying a "hold your horses" signal intended to allow more time to settle on the best option. The aim of the present study was 2-fold: 1) to extend these observations by providing evidence that the STN may influence and prevent the execution of any response even during low-conflict decisions; and 2) to identify the neural correlates of this effect.Methods: We measured regional cerebral blood flow during a Go/NoGo and a control (Go) task to study the motor improvement and response inhibition deficits associated with STN-DBS in patients with PD.Results: Although it improved Unified Parkinson Disease Rating Scale motor ratings and induced a global decrease in reaction time during task performance, STN-DBS impaired response inhibition, as revealed by an increase in commission errors in NoGo trials. These behavioral effects were accompanied by changes in synaptic activity consisting of a reduced activation in the cortical networks responsible for reactive and proactive response inhibition.Interpretation: The present results suggest that although it improves motor functions in PD patients, modulation of STN hyperactivity with DBS may tend at the same time to favor the appearance of impulsive behavior by acting on the gating mechanism involved in response initiation.

We assessed the effects of deep brain stimulation of the subthalamic nucleus (STN-DBS) or internal pallidum (GPi-DBS) on health-related quality of life (HrQoL) in patients with advanced Parkinson's disease participating in a previously reported multicenter trial. Sickness Impact Profile (SIP) questionnaires were available for analysis in a subgroup of n = 20/20 patients with GPi-DBS and n = 45/49 patients with STN-DBS at baseline, 6 and 36 months. The SIP provides a physical dimension and a psychosocial dimension sum score and 12 category scores: Alertness/Intellectual Behavior (AIB), Ambulation (A), Body Care and Movement (BCM), Communication (C), Eating (E), Emotional Behavior (EB), Home Management (HM), Mobility (M), Recreation and Pastimes (RP), Sleep and Rest (SR), Social Interaction (SI), and Work (W). Motor functioning was assessed by means of the Unified Parkinson's Disease Rating Scale and diaries. At 6 months significant improvements in off-period motor symptoms and activities of daily living were paralleled by significant reductions in the total, physical, and psychosocial SIP score in both treatment groups. At 3 years, sustained improvements were observed in the physical dimension score, BCM, E, M, RP after STN-DBS and M, SI after GPi-DBS. All other SIP subscores approached baseline values, but were still the same or better (except C) whereas motor functioning remained stable after 36 months. STN-DBS and GPi-DBS led to significant early improvements in HrQoL. Despite sustained motor improvements many of these initial benefits were lost after 3 years. This may reflect either progression of the disease or adaptive changes in the subjective perception of health-related wellbeing over time.

Subthalamic nucleus deep brain stimulation (STN-DBS) is effective in advanced Parkinson's disease (PD), but its effects on the levodopa response are unclear. We studied the levodopa response after long-term STN-DBS, STN-DBS efficacy and predictive value of preoperative levodopa response to long-term DBS benefit in 33 PD patients with bilateral STN-DBS. Patients were assessed using the Unified Parkinson's Disease Rating Scale preoperatively (with and without medications) and postoperatively (without medications or stimulation, with only medications or stimulation, and with both medications and stimulation). Levodopa response significantly decreased postoperatively by 31.1% at 3 years and 32.3% at 5 years, possibly related to the reduction in medication requirement, direct STN stimulation effect or PD progression. STN-DBS alone significantly improved motor scores (37.2% at 3 years and 35.1% at 5 years) and activities of daily living scores (27.1% at 3 years and 19.2% at 5 years). Anti-PD drugs were significantly reduced by 47.9% at 3 years and 39.8% at 5 years. However, the magnitude of the preoperative response to levodopa did not predict DBS benefit at 3 and 5 years.

Bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) was performed in a patient with Huntington's disease (HD) with severe chorea. Stimulation at 40 and 130 Hz improved chorea. Stimulation at 130 Hz slightly worsened bradykinesia overall, whereas 40 Hz had little effect. A [15O] H2O positron emission tomography showed increased regional cerebral blood flow in motor decision making and execution areas more evident at 40 Hz. Adjustment of stimulation parameters in GPi DBS may have the potential to optimize the motor response in HD, improving chorea without aggravating bradykinesia.

High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves the motor symptoms of Parkinson's disease (PD). Opposite changes in mood, such as mania or depression, have been reported after surgery, but it is not known whether these side effects are specifically related to STN DBS. To learn whether STN DBS also influences the limbic loop, we investigated acute subjective psychotropic effects related to levodopa or bilateral STN DBS. After a median postoperative follow-up of 12 months, 50 PD patients completed the Addiction Research Center Inventory (ARCI), assessing subjective psychotropic effects in four conditions: off-drug/on-stimulation; off-drug/off-stimulation; on-drug/off-stimulation; and on-drug/on-stimulation. Both levodopa and STN DBS improved all the ARCI subscales, indicating subjective feelings of well being, euphoria, increase in motivation, and decrease in fatigue, anxiety, and tension. A suprathreshold dose of levodopa was significantly more effective than STN DBS, using the same electrical parameters as for chronic stimulation, on four of the five ARCI subscales. We concluded that 1) both STN DBS and levodopa have synergistic acute beneficial psychotropic effects in PD, 2) the psychotropic effects of both treatments need to be considered in the long-term management of chronic STN DBS, and 3) the results indicate an involvement of the limbic STN in mood disorders of PD.

Deep brain stimulation (DBS) is a neurosurgical treatment of Parkinson's disease that is applied to three targets: the ventral intermediate nucleus of the thalamus (Vim), the globus pallidus internas (GPi) and the subthalamic nucleus (STN). Vim DBS mainly improves contralateral tremor and, therefore, is being supplanted by DBS of the two other targets, even in patients with tremor dominant disease. STN and GPi DBS improve off-motor phases and dyskinesias. There is little comparative data between these procedures. The magnitude of the motor improvement seems more constant with STN than GPi DBS. STN DBS allows a decrease in antiparkinsonian drug doses and consumes moderate current. These advantages of STN over GPi DBS are offset by the need for more intensive postoperative management. The DBS procedure has the unique advantage of reversibility and adjustability over time. Patients with young-onset Parkinson's disease suffering from levodopa-induced motor complications but still responding well to levodopa and who exhibit no behavioral, mood, or cognitive impairment benefit the most from STN DBS. Adverse effects more specific of the DBS procedure are infection, cutaneous erosion, and lead breaking or disconnection. Intracranial electrode implantation can induce a hematoma or contusion. Most authors agree that the benefit to risk ratio of DBS is favorable.

Studying the clinical effects induced by electrical stimulation of the subthalamic nucleus (STN) area in a parkinsonian patient under local anesthesia is a mandatory step to determine the precise location of the final chronic electrode. Using multiple microelectrodes, preferably in a concentric parallel array allows a precise mapping of the STN region. The most reliable features to determine the suitable target are stimulation-induced dyskinesias and rigidity decrease at a low intensity without adverse effects or only at far higher intensities. New skills are needed to assess all stimulation-induced effects and interpret them in anatomo-functional terms.

Unilateral pallidotomy has been effectively used to treat parkinsonism and reduce levodopa induced dyskinesia (LID). We sought to determine the long-term effects of pallidotomy on LID in 10 patients who had initial benefit from pallidotomy but went on to require DBS surgery for symptom progression. The Dyskinesia Rating Scale (DRS) was used to rate and quantify LID in a blinded fashion. Though sample size was small, there was a trend towards a reduction in LID lasting up to 12 years suggesting that posteroventral pallidotomy may provide sustained benefit in reducing LID. © 2010 Movement Disorder Society

Three patients who presented with parkinsonian signs resulting from a focal midbrain lesion are reported. In all patients parkinsonian features occurred acutely and improved following acute challenge with apomorphine but not with levodopa. Remission of parkinsonian signs occurred spontaneously to a different degree. Inconsistent clinical response following administration of levodopa has been well documented in patients with focal midbrain lesions associated with parkinsonian signs; however, the efficacy of apomorphine has not been tested before. Anatomic or etiologic features do not allow us to predict in which cases parkinsonian signs secondary to a midbrain lesion would respond to levodopa or to dopamine agonists. A trial with apomorphine is warranted in all such cases.