Reduced levodopa-induced complications after 5 years of subthalamic stimulation in Parkinson’s disease: a second honeymoon

Deep brain stimulation in PD: risk of complications, morbidity, and hospitalizations: a systematic review

Introduction

Parkinson's disease (PD) is a progressive and debilitating neurological disorder. While dopaminergic medication improves PD symptoms, continued management is complicated by continued symptom progression, increasing medication fluctuations, and medication-related dyskinesia. Deep brain stimulation (DBS) surgery is a well-accepted and widespread treatment often utilized to address these symptoms in advanced PD. However, DBS may also lead to complications requiring hospitalization. In addition, patients with PD and DBS may have specialized care needs during hospitalization.

Methods

This systematic review seeks to characterize the complications and risk of hospitalization following DBS surgery. Patient risk factors and modifications to DBS surgical techniques that may affect surgical risk are also discussed.

Results

It is found that, when candidates are carefully screened, DBS is a relatively low-risk procedure, but rate of hospitalization is somewhat increased for DBS patients.

Discussion

More research is needed to determine the relative influence of more advanced disease vs. DBS itself in increased rate of hospitalization, but education about DBS and PD is important to insure effective patient care within the hospital.

Retrospective Multicenter Study on Outcome Measurement for Dyskinesia Improvement in Parkinson's Disease Patients with Pallidal and Subthalamic Nucleus Deep Brain Stimulation

Deep brain stimulation (DBS) is an effective treatment for dyskinesia in patients with Parkinson’s disease (PD), among which the therapeutic targets commonly used include the subthalamic nucleus (STN) and the globus pallidus internus (GPi). Levodopa-induced dyskinesia (LID) is one of the common motor complications arising in PD patients on chronic treatment with levodopa. In this article, we retrospectively evaluated the outcomes of LID with the Unified Dyskinesia Rating Scale (UDysRS) in patients who underwent DBS in multiple centers with a GPi or an STN target. Meanwhile, the Med off MDS-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS-Ⅲ) and the levodopa equivalent daily dose (LEDD) were also observed as secondary indicators. PD patients with a GPi target showed a more significant improvement in the UDysRS compared with an STN target (92.9 ± 16.7% vs. 66.0 ± 33.6%, p < 0.0001). Both the GPi and the STN showed similar improvement in Med off UPDRS-III scores (49.8 ± 22.6% vs. 52.3 ± 29.5%, p = 0.5458). However, the LEDD was obviously reduced with the STN target compared with the GPi target (44.6 ± 28.1% vs. 12.2 ± 45.8%, p = 0.006).

Neurostimulation as a Method of Treatment and a Preventive Measure in Canine Drug-Resistant Epilepsy: Current State and Future Prospects

Modulation of neuronal activity for seizure control using various methods of neurostimulation is a rapidly developing field in epileptology, especially in treatment of refractory epilepsy. Promising results in human clinical practice, such as diminished seizure burden, reduced incidence of sudden unexplained death in epilepsy, and improved quality of life has brought neurostimulation into the focus of veterinary medicine as a therapeutic option. This article provides a comprehensive review of available neurostimulation methods for seizure management in drug-resistant epilepsy in canine patients. Recent progress in non-invasive modalities, such as repetitive transcranial magnetic stimulation and transcutaneous vagus nerve stimulation is highlighted. We further discuss potential future advances and their plausible application as means for preventing epileptogenesis in dogs.

Long-term Outcomes (15 Years) After Subthalamic Nucleus Deep Brain Stimulation in Patients With Parkinson Disease

OBJECTIVE

To evaluate the effects of deep brain stimulation of the subthalamic nucleus (STN-DBS) on motor complications in patients with Parkinson disease (PD) beyond 15 years after surgery.

METHODS

Data on motor complications, quality of life (QoL), activities of daily living, Unified Parkinson's Disease Rating Scale motor scores, dopaminergic treatment, stimulation measures, and side effects of STN-DBS were retrospectively retrieved and compared before surgery, at 1 year, and beyond 15 years after bilateral STN-DBS.

RESULTS

Fifty-one patients with 17.06 ± 2.18 years STN-DBS follow-up were recruited. Compared to baseline, the time spent with dyskinesia and the time spent in the "off" state were reduced by 75% (p < 0.001) and by 58.7% (p < 0.001), respectively. Moreover, dopaminergic drugs were reduced by 50.6% (p < 0.001). Parkinson's Disease Quality of Life Questionnaire total score and the emotional function and social function domains improved 13.8% (p = 0.005), 13.6% (p = 0.01), and 29.9% (p < 0.001), respectively. Few and mostly manageable device-related adverse events were observed during the follow-up.

CONCLUSIONS

STN-DBS is effective beyond 15 years from the intervention, notably with significant improvement in motor complications and stable reduction of dopaminergic drugs. Furthermore, despite the natural continuous progression of PD with worsening of levodopa-resistant motor and nonmotor symptoms over the years, patients undergoing STN-DBS could maintain an improvement in QoL.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that, for patients with PD, STN-DBS remains effective at treating motor complications 15 years after surgery.

Bilateral subthalamic nucleus deep brain stimulation is an effective treatment for diphasic dyskinesia

BACKGROUND AND PURPOSE

The purpose was to assess the effect of bilateral subthalamic nucleus deep brain stimulation (STN DBS) on diphasic dyskinesia in patients with Parkinson disease (PD) and to assess the factors associated with the remission of diphasic dyskinesia.

METHODS

Medical records for PD patients who underwent bilateral STN DBS at the Movement Disorder Center of Seoul National University Hospital from March 2005 to November 2016 were reviewed. Patients were evaluated preoperatively and at 3, 6 and 12 months after surgery, and annually thereafter. The presence of peak-dose dyskinesia and diphasic dyskinesia is based on the interview and examination of patients at baseline and at each follow-up.

RESULTS

Amongst 202 patients who underwent STN DBS, 66 patients who had diphasic dyskinesia preoperatively were included in the analysis. Diphasic dyskinesia disappeared in 49 (74%) after surgery. In 27 (55.1%) patients whose diphasic dyskinesia disappeared after DBS, peak-dose and diphasic dyskinesia disappeared persistently from as early as 3 months postoperatively. Age at onset was younger and disease duration at surgery was longer in patients whose diphasic dyskinesia persisted compared with patients whose diphasic dyskinesia disappeared. Multivariate Cox regression analysis demonstrated that patients with greater postoperative decrease of dopaminergic medications were more likely to have remission of diphasic dyskinesia.

CONCLUSION

This study showed that bilateral STN DBS is effective in controlling diphasic dyskinesia and should be considered in PD patients with diphasic dyskinesia.

Deep Brain Stimulation in Parkinson's Disease: Still Effective After More Than 8 Years

Background

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is well established and the most effective treatment for advanced Parkinson's disease (PD). However, little is known of the long-term effects.

Objectives

The aim of this study was to examine the long-term effects of STN-DBS in PD and evaluate the effect of reprogramming after more than 8 years of treatment.

Methods

A total of 82 patients underwent surgery in Copenhagen between 2001 and 2008. Before surgery and at 8 to 15 years follow-up, the patients were rated with the Unified Parkinson's Disease Rating Scale (UPDRS) with and without stimulation and medicine. Furthermore, at long-term follow-up, the patients were offered a systemic reprogramming of the stimulation settings. Data from patients' medical records were collected. The mean (range) age at surgery was 60 (42-78) years, and the duration of disease was 13 (5-25) years. A total of 30 patients completed the long-term follow-up.

Results

The mean reduction of the motor UPDRS by medication before surgery was 52%. The improvement of motor UPDRS with stimulation alone compared with motor UPDRS with neither stimulation nor medication was 61% at 1 year and 39% at 8 to 15 years after surgery (before reprogramming). Compared with before surgery, medication was reduced by 55% after 1 year and 44% after 8 to 15 years. After reprogramming, most patients improved.

Conclusions

STN-DBS remains effective in the long run, with a sustained reduction of medication in the 30 of 82 patients available for long-term follow-up. Reprogramming is effective even in the late stages of PD and after many years of treatment.

Stimulation-Induced Dyskinesia After Subthalamic Nucleus Deep Brain Stimulation in Patients With Meige Syndrome

OBJECTIVES

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is increasingly used to treat Meige syndrome (MS) and markedly improves symptoms. Stimulation-induced dyskinesia (SID), which adversely affects surgical outcomes and patient satisfaction, may, however, occur in some patients. This study attempts to explore possible causes of SID.

MATERIALS AND METHODS

Retrospectively collected clinical data on 32 patients who underwent STN-DBS between October 2016 and April 2019 were analyzed. Clinical outcomes were assessed pre- and post-surgery, using the Burke-Fahn-Marsden dystonia rating scale (BFMDRS). Patients were divided into a dyskinesia group and a non-dyskinesia group, according to whether or not they experienced persistent SID during follow-up. The coordinates of the active contacts were calculated from post-operative computerized tomography or magnetic resonance imaging, using the inter-commissural line as a reference. At final follow-up, the main stimulatory parameters for further study included pulse width, voltage, and frequency.

RESULTS

At final follow-up (mean = 16.3 ± 7.2 months), MS patients had improved BFMDRS total scores compared with pre-surgical scores (mean improvement = 79.0%, p < 0.0001). The mean improvement in BFMDRS total scores in the dyskinesia (n = 10) and non-dyskinesia (n = 22) groups were 81.6 ± 8.8% and 77.9 ± 14.2%, respectively. The mean minimum voltage to induce dyskinesia was 1.7 ± 0.3 V. The programmed parameters of both groups were similar. When compared with the non-dyskinesia group, active stimulatory contact coordinates in the dyskinesia group were inferior (mean left side: z = -2.3 ± 1.7 mm vs. z = -1.2 ± 1.5 mm; p = 0.0282; mean right side: z = -2.7 ± 1.9 mm vs. z = -2.3 ± 1.7 mm; p = 0.0256). The x and y coordinates were similar.

CONCLUSION

STN-DBS is an effective intervention for MS, providing marked improvements in clinical symptoms; SID may, however occur in the subsequent programming control process. Comparing patients with/without dyskinesia, the active contacts were located closer to the inferior part of the STN in patients with dyskinesia, which may provide an explanation for the dyskinesia.

Longitudinal medication profile and cost savings in Parkinson's disease patients after bilateral subthalamic nucleus deep brain stimulation

INTRODUCTION

Deep brain stimulation of the subthalamic nucleus (STN DBS) has been shown to reduce antiparkinsonian medication in Parkinson's disease. We aimed to investigate the changes in long-term medication profile with STN DBS.

METHODS

Antiparkinsonian medication data for 56 patients were collected from as early as 3 years before STN DBS up to 10 years after. Cost spending on medication changes was analyzed. Mean levodopa equivalent daily dose (LEDD) was projected 10 years into the future based on preoperative data to create a comparator group wherein the patients did not undergo STN DBS. Use of neuroleptics and antidepressants was also recorded.

RESULTS

LEDD requirement was significantly reduced by a mean of 31 ± 2% over 10 years after DBS, from 1049 ± 381 mg at pre-DBS baseline, to 713 ± 392 mg at 1 year post-DBS, and 712 ± 385 mg at 10 years post-DBS. This was associated with a mean reduction of 35 ± 3% in medicine cost. Modeled LEDD requirements for not having STN DBS were in the range of 1489 mg to 2721 mg at 10 years post-DBS (109-282% higher than the observed mean LEDD in DBS cohort). The proportion of patients increased from 5% before STN DBS to 14% at 10 year post-DBS for neuroleptics, and 11-23% for antidepressants.

CONCLUSION

STN DBS led to LEDD reduction and antiparkinsonian medication cost savings in our South-East Asian cohort. Medication reduction with STN DBS in our cohort over the 10-year period was comparable to those reported in Western populations.

Long-term outcomes of deep brain stimulation in Parkinson disease

The efficacy of deep brain stimulation (DBS) for Parkinson disease (PD) is well established for up to 1 or 2 years, but long-term outcome data are still limited. In this Review, we critically discuss the evidence on the long-term outcomes of DBS and consider the clinical implications. Although many patients are lost to follow-up, the evidence indicates that subthalamic nucleus DBS improves motor function for up to 10 years, although the magnitude of improvement tends to decline over time. Functional scores recorded during on-medication periods worsen more quickly than those recorded in off periods, consistent with the degeneration of non-dopaminergic pathways. Dyskinesia, motor fluctuations and activities of daily living in off periods remain improved at 5 years, but quality-of-life scores have usually fallen below preoperative levels. The incidence and severity of dementia among patients receiving DBS are comparable to those among patients who receive medical treatment. Severe adverse events are rare, but adverse events such as dysarthria are common and probably under-reported. Long-term data on the outcomes of globus pallidus interna DBS are limited and mostly confirm the efficacy for dyskinesia. A trend towards offering DBS in the earlier stages of PD creates a need to identify factors that predict long-term outcomes and to discuss realistic expectations with patients preoperatively.

Pallidal versus subthalamic nucleus deep brain stimulation for levodopa-induced dyskinesia

OBJECTIVE

To compare the efficacy of subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) on reducing levodopa-induced dyskinesia (LID) in Parkinson's disease, and to explore the potential underlying mechanisms.

METHODS

We retrospectively assessed clinical outcomes in 43 patients with preoperative LID who underwent DBS targeting the STN (20/43) or GPi (23/43). The primary clinical outcome was the change from baseline in the Unified Dyskinesia Rating Scale (UDysRS) and secondary outcomes included changes in the total daily levodopa equivalent dose, the drug-off Unified Parkinson Disease Rating Scale Part Ⅲ at the last follow-up (median, 18 months), adverse effects, and programming settings. Correlation analysis was used to find potential associated factors that could be used to predict the efficacy of DBS for dyskinesia management.

RESULTS

Compared to baseline, both the STN group and the GPi group showed significant improvement in LID with 60.73 ± 40.29% (mean ± standard deviation) and 93.78 ± 14.15% improvement, respectively, according to the UDysRS score. Furthermore, GPi-DBS provided greater clinical benefit in the improvement of dyskinesia (P < 0.05) compared to the STN. Compared to the GPi group, the levodopa equivalent dose reduction was greater in the STN group at the last follow-up (43.81% vs. 13.29%, P < 0.05). For the correlation analysis, the improvement in the UDysRS outcomes were significantly associated with a reduction in levodopa equivalent dose in the STN group (r = 0.543, P = 0.013), but not in the GPi group (r = -0.056, P = 0.801).

INTERPRETATION

Both STN and GPi-DBS have a beneficial effect on LID but GPi-DBS provided greater anti-dyskinetic effects. Dyskinesia suppression for STN-DBS may depend on the reduction of levodopa equivalent dose. Unlike the STN, GPi-DBS might exert a direct and independent anti-dyskinesia effect.

Subthalamic deep brain stimulation and levodopa in Parkinson's disease: a meta-analysis of combined effects

INTRODUCTION

While subthalamic nucleus deep brain stimulation (STN-DBS) and levodopa improve motor symptoms in Parkinson disease (PD) to a similar magnitude, their combined effect remains unclear. We sought to evaluate whether STN-DBS and levodopa yield differential effects on motor outcomes, dyskinesia, and activities of daily living (ADL) when combined compared to when administered alone.

METHODS

We conducted a meta-analysis of all studies reporting motor, dyskinesia, and ADL outcomes after bilateral STN-DBS in PD with presurgical Unified Parkinson's Disease Rating Scale (UPDRS-III) in Medication-OFF and Medication-ON states and postsurgical assessments in four conditions: Stimulation-ON/Medication-ON, Stimulation-ON/Medication-OFF, Stimulation-OFF/Medication-ON, and Stimulation-OFF/Medication-OFF. Dyskinesia duration (UPDRS item 32) and ADL (UPDRS-II) were compared between high and low postsurgical levodopa equivalent daily dose (LEDD) reduction. Random-effects meta-analyses using generic-inverse variance were conducted. Confidence in outcomes effect sizes was assessed.

RESULTS

Twelve studies were included (n = 401 patients). Stimulation-ON/Medication-ON was associated with an UPDRS-III improvement of - 35.7 points [95% confidence interval, - 40.4, - 31.0] compared with Stimulation-OFF/Medication-OFF, - 11.2 points [- 14.0, - 8.4] compared with Stimulation-OFF/Medication-ON, and - 9.5 points [- 11.0, - 8.0] compared to Stimulation-ON/Medication-OFF within 5 years. The difference was maintained beyond 5 years by - 28.6 [- 32.8, - 24.4], - 8.1 [- 10.2, - 5.9], and - 8.0 [- 10.3, - 5.6], respectively. No difference was observed between Stimulation-ON/Medication-OFF and Stimulation-OFF/Medication-ON within and beyond 5 years. Dyskinesia duration and ADL outcomes were similar in high vs. low postsurgical LEDD reduction.

CONCLUSION

Subthalamic nucleus deep brain stimulation and levodopa independently lessened motor severity in PD to a similar magnitude, but their combined effect was greater than either treatment alone, suggesting therapeutic synergism.

Current Topics in Deep Brain Stimulation for Parkinson Disease

There is a long history of surgical treatment for Parkinson disease (PD). After pioneering trials and errors, the current primary surgical treatment for PD is deep brain stimulation (DBS). DBS is a promising treatment option for patients with medically refractory PD. However, there are still many problems and controversies associated with DBS. In this review, we discuss current issues in DBS for PD, including patient selection, clinical outcomes, complications, target selection, long-term outcomes, management of axial symptoms, timing of surgery, surgical procedures, cost-effectiveness, and new technology.

Effect of Subthalamic Deep Brain Stimulation on Levodopa-Induced Dyskinesia in Parkinson's Disease

PURPOSE

To evaluate the effect of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) on levodopa-induced peak-dose dyskinesia in patients with Parkinson's disease (PD).

MATERIALS AND METHODS

A retrospective review was conducted on patients who underwent STN DBS for PD from May 2000 to July 2012. Only patients with levodopa-induced dyskinesia prior to surgery and more than 1 year of available follow-up data after DBS were included. The outcome measures included the dyskinesia subscore of the Unified Parkinson's Disease Rating Scale (UPDRS) part IV (items 32 to 34 of UPDRS part IV) and the levodopa equivalent daily dose (LEDD). The patients were divided into two groups based on preoperative to postoperative LEDD change at 12 months after the surgery: Group 1, LEDD decrease >15%; Group 2, all other patients. Group 2 was further divided by the location of DBS leads.

RESULTS

Of the 100 patients enrolled, 67 were in Group 1, while those remaining were in Group 2. Twelve months after STN DBS, Groups 1 and 2 showed improvements of 61.90% and 57.14%, respectively, in the dyskinesia subscore. Group 1 was more likely to experience dyskinesia suppression; however, the association between the groups and dyskinesia suppression was not statistically significant (p=0.619). In Group 2, dyskinesia was significantly decreased by stimulation of the area above the STN in 18 patients compared to stimulation of the STN in 15 patients (p=0.048).

CONCLUSION

Levodopa-induced dyskinesia is attenuated by STN DBS without reducing the levodopa dosage.

Pathophysiology of L-dopa-induced motor and non-motor complications in Parkinson's disease

Involuntary movements, or dyskinesia, represent a debilitating complication of levodopa (L-dopa) therapy for Parkinson's disease (PD). L-dopa-induced dyskinesia (LID) are ultimately experienced by the vast majority of patients. In addition, psychiatric conditions often manifested as compulsive behaviours, are emerging as a serious problem in the management of L-dopa therapy. The present review attempts to provide an overview of our current understanding of dyskinesia and other L-dopa-induced dysfunctions, a field that dramatically evolved in the past twenty years. In view of the extensive literature on LID, there appeared a critical need to re-frame the concepts, to highlight the most suitable models, to review the central nervous system (CNS) circuitry that may be involved, and to propose a pathophysiological framework was timely and necessary. An updated review to clarify our understanding of LID and other L-dopa-related side effects was therefore timely and necessary. This review should help in the development of novel therapeutic strategies aimed at preventing the generation of dyskinetic symptoms.

Axial disability and deep brain stimulation in patients with Parkinson disease

Axial motor signs-including gait impairment, postural instability and postural abnormalities-are common and debilitating symptoms in patients with advanced Parkinson disease. Dopamine replacement therapy and physiotherapy provide, at best, partial relief from axial motor symptoms. In carefully selected candidates, deep brain stimulation (DBS) of the subthalamic nucleus or globus pallidus internus is an established treatment for 'appendicular' motor signs (limb tremor, bradykinesia and rigidity). However, the effects of DBS on axial signs are much less clear, presumably because motor control of axial and appendicular functions is mediated by different anatomical-functional pathways. Here, we discuss the successes and failures of DBS in managing axial motor signs. We systematically address a series of common clinical questions associated with the preoperative phase, during which patients presenting with prominent axial signs are considered for DBS implantation surgery, and the postoperative phase, in particular, the management of axial motor signs that newly develop as postoperative complications, either acutely or with a delay. We also address the possible merits of new targets-including the pedunculopontine nucleus area, zona incerta and substantia nigra pars reticulata-to specifically alleviate axial symptoms. Supported by a rapidly growing body of evidence, this practically oriented Review aims to support decision-making in the management of axial symptoms.

Axial disability and deep brain stimulation in patients with Parkinson disease

Axial motor signs-including gait impairment, postural instability and postural abnormalities-are common and debilitating symptoms in patients with advanced Parkinson disease. Dopamine replacement therapy and physiotherapy provide, at best, partial relief from axial motor symptoms. In carefully selected candidates, deep brain stimulation (DBS) of the subthalamic nucleus or globus pallidus internus is an established treatment for 'appendicular' motor signs (limb tremor, bradykinesia and rigidity). However, the effects of DBS on axial signs are much less clear, presumably because motor control of axial and appendicular functions is mediated by different anatomical-functional pathways. Here, we discuss the successes and failures of DBS in managing axial motor signs. We systematically address a series of common clinical questions associated with the preoperative phase, during which patients presenting with prominent axial signs are considered for DBS implantation surgery, and the postoperative phase, in particular, the management of axial motor signs that newly develop as postoperative complications, either acutely or with a delay. We also address the possible merits of new targets-including the pedunculopontine nucleus area, zona incerta and substantia nigra pars reticulata-to specifically alleviate axial symptoms. Supported by a rapidly growing body of evidence, this practically oriented Review aims to support decision-making in the management of axial symptoms.

[Deep brain stimulation for Parkinson's disease: timing and patient selection]

Deep brain stimulation (DBS) is an effective and evidence-based treatment option for Parkinson's disease. Studies have shown that DBS has good and long-term effects on motor function and quality of life for patients in an advanced stage of the disease and that it is more effective than medical therapy alone. Moreover, a favorable effect of DBS could also be detected at an earlier stage of the disease. On the other hand, possible risks and side effects of the procedure need to be taken into consideration. These can manifest as procedure-related complications, such as bleeding and infections in addition to stimulation-associated phenomena, such as neuropsychiatric disorders and motor side effects. Despite the good effects of DBS important issues still need to be addressed which will be discussed in this article considering the results of several new randomized and controlled clinical studies. For patients with Parkinson's disease with early fluctuations and dyskinesia, DBS has been found to be superior to the best pharmaceutical treatment; therefore, DBS can be considered as a treatment option in the earlier course of the disease. The diagnostic evaluation and the exclusion of contraindications are crucial for patient selection. The choice of the target should be based on the individual symptoms in patients although the subthalamic nucleus (STN) can be considered the standard target. In every case an individual assessment of chances and risks must be conducted and realistic goals and reasonable expectations must be defined.

Controlled general anaesthesia for subthalamic nucleus stimulation in Parkinson's disease

OBJECTIVE

To report the short-term (1 year) and long-term (5 years) outcome of patients with Parkinson's disease (PD) with subthalamic nucleus (STN) stimulation operated upon under controlled general anaesthesia (GA).

METHODS

213 consecutive patients with PD were included between January 2000 and March 2009 and operated upon under a particular type of GA with close control of the level of sedation allowing intraoperative recordings. 188 patients were assessed 1 year postoperatively. 65 patients also completed the long-term observation period and were evaluated 5 years postoperatively.

RESULTS

The Unified PD Rating Scale III score in the 'Off drug--On stim' condition was improved at 1 year and 5 years by 61% and 37%, respectively, (p<0.001). Motor complications decreased at short-term and long-term by 68% and 65%, respectively, for dyskinesia and by 52% and 48%, respectively, for fluctuations, (p<0.001). Dopaminergic treatment could also be reduced at short-term and long-term by 46% and 49%, respectively (p<0.001). There was no significant modification of mood and cognition assessments (Mattis scale and Beck depression inventory) at 1 year and 5 years. Concerning the main adverse events related to the surgery, we report four haematomas (1.9%) with two deaths (0.9%), eight cases of transient confusion (3.7%) and no epileptic seizure.

CONCLUSIONS

Our results confirm that STN stimulation performed under controlled GA is efficient and has similar short-term and long-term motor effects than intervention under local anaesthesia. Furthermore, this specific procedure is not associated with more adverse events. The success of such an intervention requires strict anaesthetic monitoring and accurate STN identification.

Subthalamic neurostimulation for Parkinson's disease with early fluctuations: balancing the risks and benefits

Electrical stimulation of the subthalamic nucleus is an established treatment for patients with advanced Parkinson's disease with pharmacologically unresponsive fluctuations. Compared with pharmacological treatment, subthalamic neurostimulation significantly improves motor symptoms, particularly during the phases of poor response to drug treatment, and reduces the severity of dyskinesias. Importantly, it also significantly improves quality of life and other integral measures of disease severity. The treatment response can last for more than 10 years, although there is no evidence that levodopa-resistant symptoms are delayed by subthalamic neurostimulation. At present, the mean disease duration for patients at the time of implantation is 12 years. In a recent study (EARLYSTIM) in patients with a disease duration of 7·5 years and fluctuations for 1·5 years, similar improvements in clinical outcomes were reported. These findings suggest that neurostimulation of the subthalamic nucleus could be used earlier in the disease course for carefully selected patients if the benefits of the treatment are weighed against the surgical risks and the lifelong need for specialised care by an experienced team. As mobility is consistently improved during the times with poor mobility by reducing fluctuations and delaying levodopa-sensitive complications, we propose that this treatment changes the disease course.

Factors related to outcomes of subthalamic deep brain stimulation in Parkinson's disease

OBJECTIVE

Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective treatment of choice for patients with advanced idiopathic Parkinson's disease (PD) who have motor complication with medication. The objectives of this study are to analyze long-term follow-up data of STN DBS cases and to identify the factors related to outcomes.

METHODS

Fifty-two PD patients who underwent STN DBS were followed-up for more than 3 years. The Unified Parkinsons Disease Rating Scale (UPDRS) and other clinical profiles were assessed preoperatively and during follow-up. A linear regression model was used to analyze whether factors predict the results of STN DBS. We divided the study individuals into subgroups according to several factors and compared subgroups.

RESULTS

Preoperative activity of daily living (ADL) and the magnitude of preoperative levodopa response were shown to predict the improvement in UPDRS part II without medication, and preoperative ADL and levodopa equivalent dose (LED) were shown to predict the improvement in UPDRS part II with medication. In UPDRS part III with medication, the magnitude of preoperative levodopa response was a predicting factor.

CONCLUSION

The intensity of preoperative levodopa response was a strong factor for motor outcome. And preoperative ADL and LED were strong factors for ADL improvement. More vigorous studies should be conducted to elucidate how levodopa-induced motor complications are ameliorated after STN DBS.

Clinical outcome of deep brain stimulation for Parkinson's disease

Deep brain stimulation is one of the most effective treatments of Parkinson's disease (PD). This report summarizes the state of the art as at January 2013. Stimulation of the subthalamic nucleus is the most commonly used approach. It improves the core motor symptoms better than medication in patients with advanced disease. It also improves the majority of nonmotor symptoms, such as mood, impulse control disorders, sleep, and some autonomic dysfunctions. Quality of life (QoL) is improved significantly more than with medication. Long-term data show that the treatment is effective for up to 10 years, but the late appearance of l-dopa-resistant symptoms is seemingly not influenced. Internal globus pallidus (GPi) stimulation is less well studied but seems to have similar short-term efficacy. Importantly l-dopa use cannot be reduced with GPi DBS, which is a major disadvantage for patients suffering from medication side-effects, although gait may be influenced more positively. Although short-term QoL improvement seems to be similar to that for subthalamic nucleus (STN) DBS - gait and speech may be better improved - long-term data are rare for GPi DBS. Thalamic stimulation in the ventral intermediate nucleus (VIM) is applied only in tremor-dominant elderly patients. The treatment improves the dopa-sensitive symptoms and effectively reduces fluctuations leading to an overall QoL improvement. Although most of the controlled studies have been on advanced PD, the recently published EARLYSTIM study suggests that even patients with a very short duration of their fluctuations and dyskinesia are doing significantly better with neurostimulation in terms of QoL and all major motor outcome parameters.

Targeting the brain: considerations in 332 consecutive patients treated by deep brain stimulation (DBS) for severe neurological diseases

Deep brain stimulation (DBS) extends the treatment of some severe neurological diseases beyond pharmacological and conservative therapy. Our experience extends the field of DBS beyond the treatment of Parkinson disease and dystonia, including several other diseases such as cluster headache and disruptive behavior. Since 1993, at the Istituto Nazionale Neurologico "Carlo Besta" in Milan, 580 deep brain electrodes were implanted in 332 patients. The DBS targets include Stn, GPi, Voa, Vop, Vim, CM-pf, pHyp, cZi, Nacc, IC, PPN, and Brodmann areas 24 and 25. Three hundred patients are still available for follow-up and therapeutic considerations. DBS gave a new therapeutic chance to these patients affected by severe neurological diseases and in some cases controlled life-threatening pathological conditions, which would otherwise result in the death of the patient such as in status dystonicus, status epilepticus and post-stroke hemiballismus. The balance of DBS in severe neurological disease is strongly positive even if further investigations and studies are needed to search for new applications and refine the selection criteria for the actual indications.

Long-term stability of effects of subthalamic stimulation in Parkinson's disease: Indian Experience

Reports of long-term effects of subthalamic (STN) stimulation for Parkinson's disease (PD) are few, mostly open-label evaluations and from Western centers. We used single-blind and open-label motor, cognitive and quality of life (QOL) evaluations to study the effects of bilateral STN stimulation in 45 patients over 5 years. Our patients showed a stable and substantial reduction in the cardinal signs of PD, motor fluctuations, and dyskinesias but less so for axial signs. The reduction in medications and the intensity of electrical stimulation needed also remained stable during follow up. Although the total QOL and its parkinsonism and social components showed sustained benefits till 5 years, the gains in emotional and systemic subsets were short lasting. Global scores for mood and cognition did not show significant worsening. Benefits of STN stimulation on the cardinal signs, motor complications, and QOL of advanced PD were substantial and sustained till 5 years. The initial benefits in axial motor signs and emotional and psychological aspects of QOL did not show similar stability. In general, the procedure had insignificant impact on cognition and mood. This is the first report of STN stimulation in Asian patients with PD.

Motor and cognitive outcome in patients with Parkinson's disease 8 years after subthalamic implants

Deep brain stimulation of the subthalamic nucleus represents the most important innovation for treatment of advanced Parkinson's disease. Prospective studies have shown that although the beneficial effects of this procedure are maintained at 5 years, axial motor features and cognitive decline may occur in the long term after the implants. In order to address some unsolved questions raised by previous studies, we evaluated a series of 20 consecutive patients who received continuous stimulation for 8 years. The overall motor improvement reported at 5 years (55.5% at Unified Parkinson's Disease Rating Scale-motor part, P < 0.001 compared with baseline) was only partly retained 3 years later (39%, P < 0.001, compared with baseline; -16.5%, P < 0.01, compared with 5 years), with differential effects on motor features: speech did not improve and postural stability worsened (P < 0.05). The preoperative levodopa equivalent daily dose was reduced by 58.2% at 5 years and by 60.3% at 8 years. In spite of subtle worsening of motor features, a dramatic impairment in functional state (-56.6% at Unified Parkinson's Disease Rating Scale-Activities of Daily Living, P < 0.01) emerged after the fifth year of stimulation. The present study did not reveal a predictive value of preoperative levodopa response, whereas few single features at baseline (such as gait and postural stability motor scores and the preoperative levodopa equivalent daily dose) could predict long-term motor outcome. A decline in verbal fluency (slightly more pronounced than after 5 years) was detected after 8 years. A significant but slight decline in tasks of abstract reasoning, episodic memory and executive function was also found. One patient had developed dementia at 5 years with further progression at 8 years. Executive dysfunction correlated significantly with postural stability, suggesting interplay between axial motor deterioration and cognition. Eight years after surgery, no significant change was observed on scales assessing depression or anxiety when compared with baseline. At 8 years, there was no significant increase of side-effects when compared with 5-year follow-up. In conclusion, deep brain stimulation of the subthalamic nucleus is a safe procedure with regard to cognitive and behavioural morbidity over long-term follow-up. However, the global benefit partly decreases later in the course of the disease, due to progression of Parkinson's disease and the appearance of medication- and stimulation-resistant symptoms.