Health-related quality of life in Parkinson's disease after pallidotomy and deep brain stimulation

Prediction of depression and anxiety via patient-assessed tremor severity, not physician-reported motor symptom severity, in patients with Parkinson's disease or essential tremor who have undergone deep brain stimulation

OBJECTIVEDeep brain stimulation (DBS) is an effective therapy for movement disorders such as idiopathic Parkinson's disease (PD) and essential tremor (ET). However, some patients who demonstrate benefit on objective motor function tests do not experience postoperative improvement in depression or anxiety, 2 important components of quality of life (QOL). Thus, to examine other possible explanations for the lack of a post-DBS correlation between improved objective motor function and decreased depression or anxiety, the authors investigated whether patient perceptions of motor symptom severity might contribute to disease-associated depression and anxiety.METHODSThe authors performed a retrospective chart review of PD and ET patients who had undergone DBS at the Cleveland Clinic in the period from 2009 to 2013. Patient demographics, diagnosis (PD, ET), motor symptom severity, and QOL measures (Primary Care Evaluation of Mental Disorders 9-item Patient Health Questionnaire [PHQ-9] for depression, Generalized Anxiety Disorder 7-item Scale [GAD-7], and patient-assessed tremor scores) were collected at 4 time points: preoperatively, postoperatively, 1-year follow-up, and 2-year follow-up. Multivariable prediction models with solutions for fixed effects were constructed to assess the correlation of predictor variables with PHQ-9 and GAD-7 scores. Predictor variables included age, sex, visit time, diagnosis (PD vs ET), patient-assessed tremor, physician-reported tremor, Unified Parkinson's Disease Rating Scale part III (UPDRS-III) score, and patient-assessed tremor over time.RESULTSSeventy PD patients and 17 ET patients were included in this analysis. Mean postoperative and 1-year follow-up UPDRS-III and physician-reported tremor scores were significantly decreased compared with preoperative scores (p < 0.0001). Two-year follow-up physician-reported tremor was also significantly decreased from preoperative scores (p < 0.0001). Only a diagnosis of PD (p = 0.0047) and the patient-assessed tremor rating (p < 0.0001) were significantly predictive of depression. A greater time since surgery, in general, significantly decreased anxiety scores (p < 0.0001) except when a worsening of patient-assessed tremor was reported over the same time period (p < 0.0013).CONCLUSIONSPatient-assessed tremor severity alone was predictive of depression in PD and ET following DBS. This finding suggests that a patient's perception of illness plays a greater role in depression than objective physical disability regardless of the time since surgical intervention. In addition, while anxiety may be attenuated by DBS, patient-assessed return of tremor over time can increase anxiety, highlighting the importance of long-term follow-up for behavioral health features in chronic neurological disorders. Together, these data suggest that the patient experience of motor symptoms plays a role in depression and anxiety-a finding that warrants consideration when evaluating, treating, and following movement disorder patients who are candidates for DBS.

Focused ultrasound thalamotomy in Parkinson disease: Nonmotor outcomes and quality of life

OBJECTIVE

To examine nonmotor outcomes and correlates of quality of life (QoL) 3 and 12 months after unilateral focused ultrasound thalamotomy in tremor-dominant Parkinson disease (TDPD).

METHODS

Twenty-seven patients with TDPD in a double-blind, sham-controlled, randomized clinical trial underwent comprehensive neuropsychological evaluations. These included assessment of mood, behavior, and QoL at baseline, 3 months, 3 months post crossover in the sham group, and 12 months after active treatment. We used Mann-Whitney U tests to assess differences between the active (n = 20) and sham (n = 7) groups at 3 months and Friedman tests to assess within-group changes after active treatment. We assessed correlations between disease variables and postoperative QoL using Kendall tau-b tests.

RESULTS

There were no differences in cognition, mood, or behavior between the active and sham groups at 3-month blinded assessment. After active treatment, there were no differences in mood or behavior. Only declines in Stroop Color Naming and phonemic fluency were observed. Patients experienced postoperative improvements in QoL and activities of daily living (ADL). Mood and behavioral symptoms, aspects of cognitive functioning, ADL, and overall motor symptom severity, but not tremor severity specifically, were associated with QoL.

CONCLUSIONS

In TDPD, unilateral focused ultrasound thalamotomy appears safe from a cognitive, mood, and behavioral perspective. QoL and ADL significantly improved following surgery. Nonmotor symptoms and ADL were more closely associated with QoL than tremor severity.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with TDPD, unilateral focused ultrasound thalamotomy did not adversely change cognition, mood, or behavior at 3 months.

Subthalamic nucleus and globus pallidus internus stimulation for the treatment of Parkinson's disease: A systematic review

Objective

Deep brain stimulation (DBS) for treatment of advanced Parkinson’s disease (PD) has two anatomical targets: the subthalamic nucleus (STN) and the globus pallidus internus (GPI). The clinical effectiveness of these two stimulation targets was compared in the present study.

Methods

A systematic review and meta-analysis was performed to evaluated the postoperative changes in the United Parkinson’s Disease Rating Scale (UPDRS) on- and off-phase, on-stimulation motor scores; activities of daily living score (ADLS); and levodopa equivalent dose (LED) after STN and GPI stimulation. Randomized and nonrandomized controlled trials of PD treated by STN and GPI stimulation were considered for inclusion.

Results

Eight published reports of eligible studies involving 599 patients met the inclusion criteria. No significant differences were observed between the STN and GPI groups in the on-medication, on-stimulation UPDRS motor score [mean difference, 2.15; 95% confidence interval (CI), −0.96–5.27] or ADLS (mean difference, 3.40; 95% CI, 0.95–7.76). Significant differences in favor of STN stimulation were noted in the off-medication, on-stimulation UPDRS motor score (mean difference, 1.67; 95% CI, 0.98–2.37) and LED (mean difference, 130.24; 95% CI, 28.82–231.65).

Conclusion

The STN may be the preferred target for DBS in consideration of medication reduction, economic efficiency, and motor function improvement in the off phase. However, treatment decisions should be made according to the individual patient’s symptoms and expectations.

Independent contributors to overall quality of life in people with advanced cancer

Background:

The definition of health for people with cancer is not focused solely on the physiology of illness and the length of life remaining, but is also concerned with improving the well-being and the quality of the life (QOL) remaining to be lived. This study aimed to identify the constructs most associated with QOL in people with advanced cancer.

Methods:

Two hundred three persons with recent diagnoses of different advanced cancers were evaluated with 65 variables representing individual and environmental factors, biological factors, symptoms, function, general health perceptions and overall QOL at diagnosis. Three independent stepwise multiple linear regressions identified the most important contributors to overall QOL. R² ranking and effect sizes were estimated and averaged by construct.

Results:

The most important contributor of overall QOL for people recently diagnosed with advanced cancer was social support. It was followed by general health perceptions, energy, social function, psychological function and physical function.

Conclusions:

We used effect sizes to summarise multiple multivariate linear regressions for a more manageable and clinically interpretable picture. The findings emphasise the importance of incorporating the assessment and treatment of relevant symptoms, functions and social support in people recently diagnosed with advanced cancer as part of their clinical care.

Neuropsychiatric symptoms in Parkinson's disease

Neuropsychiatric symptoms are common in Parkinson's disease, even at the earliest stages, and have important consequences for quality of life and daily functioning, are associated with increased carer burden and increased risk for nursing home admission. In addition to cognitive impairment, a wide range of neuropsychiatric symptoms have been reported. In this article, the epidemiology, clinical course, diagnosis, and management of some of the most common neuropsychiatric symptoms in PD are discussed: depression, anxiety, apathy, fatigue, and psychotic symptoms. Although much is known regarding the prevalence and course of these symptoms, the empirical evidence for how to manage these symptoms is limited at best. There is thus an urgent need for systematic studies for the pharmacological and non-pharmacological management of these symptoms.

Anxiety rating scales in Parkinson's disease: critique and recommendations

Anxiety syndromes are common in patients with Parkinson's disease (PD) with up to 30% suffering from panic disorder, and up to 11% from generalized anxiety disorder (GAD). Anxiety is associated with increased subjective motor symptoms, more severe gait problems, dyskinesias, freezing, and on/off fluctuations. Anxiety has a negative impact on health related quality of life and is strongly associated with depressive syndromes. Since a variety of anxiety scales have been used in PD patients, the Movement Disorder Society commissioned a task force to assess the clinimetric properties of these scales in PD. A systematic review was conducted to identify anxiety scales that have either been validated or used in patients with PD. Six anxiety rating scales were identified. These were the Beck anxiety inventory, the hospital anxiety and depression scale, the Zung self-rating anxiety scale and anxiety status inventory, the Spielberger state trait anxiety inventory, and the Hamilton anxiety rating scale. In addition, Item 5 (anxiety) of the neuropsychiatric inventory was included in the review. No scales met the criteria to be "recommended," and all scales were classified as "suggested." Essential clinimetric information is missing for all scales. Because several scales exist and have been used in PD, the task force recommends further studies of these instruments. If these studies show that the clinimetric properties of existing scales are inadequate, development of a new scale to assess anxiety in PD should be considered.

Psychosurgery and deep brain stimulation as ultima ratio treatment for refractory depression

For decades, the most severe, protracted and therapy-resistant forms of major depression have compelled clinicians and researchers to look for last resort treatment. Early psychosurgical procedures were hazardous and often associated with severe and persistent side effects including avolition, apathy and change of personality. With the introduction of psychopharmacological treatments in the 1950s, the frequency of ablative procedures declined rapidly. The past decade, however, has witnessed the resurgence of surgical strategies as a result of refined techniques and advances such as high frequency stimulation of deep brain nuclei. Recent data suggest that the overall effect of high frequency stimulation lies in the functional inhibition of neural activity in the region stimulated. Contrary to other psychosurgical procedures, high frequency stimulation reversibly modulates targeted brain areas and allows a postsurgical adaption of the stimulation parameters according to clinical outcome. With increased understanding of the brain regions and functional circuits involved in the pathogenesis of psychiatric disorders, major depression has emerged as a target for new psychosurgical approaches to selectively and precisely modulate neural areas involved in the disease process. Recent studies of minimally intervening procedures report good clinical outcome in the treatment of therapy-resistant forms of major depression. High frequency stimulation was successfully applied in several small samples of patients with treatment-resistant depression when the stimulation focused on different areas, e.g., nucleus accumbens, the lateral habenula or cortical areas. Nevertheless, the reticence toward psychosurgery, even for those patients suffering from the most debilitating forms of depression, still prevails, even though recent studies have shown significant improvement in terms of quality of life with the limitation that the number of treated cases has been small. In any event, valid and unambiguous criteria for patient eligibility have yet to be refined and standardized. In this review, we suggest possible standard criteria for the application of deep brain stimulation on patients suffering from otherwise treatment-resistant depression.

Bilateral deep brain stimulation vs best medical therapy for patients with advanced Parkinson disease: a randomized controlled trial

CONTEXT

Deep brain stimulation is an accepted treatment for advanced Parkinson disease (PD), although there are few randomized trials comparing treatments, and most studies exclude older patients.

OBJECTIVE

To compare 6-month outcomes for patients with PD who received deep brain stimulation or best medical therapy.

DESIGN, SETTING, AND PATIENTS

Randomized controlled trial of patients who received either deep brain stimulation or best medical therapy, stratified by study site and patient age (< 70 years vs > or = 70 years) at 7 Veterans Affairs and 6 university hospitals between May 2002 and October 2005. A total of 255 patients with PD (Hoehn and Yahr stage > or = 2 while not taking medications) were enrolled; 25% were aged 70 years or older. The final 6-month follow-up visit occurred in May 2006.

INTERVENTION

Bilateral deep brain stimulation of the subthalamic nucleus (n = 60) or globus pallidus (n = 61). Patients receiving best medical therapy (n = 134) were actively managed by movement disorder neurologists.

MAIN OUTCOME MEASURES

The primary outcome was time spent in the "on" state (good motor control with unimpeded motor function) without troubling dyskinesia, using motor diaries. Other outcomes included motor function, quality of life, neurocognitive function, and adverse events.

RESULTS

Patients who received deep brain stimulation gained a mean of 4.6 h/d of on time without troubling dyskinesia compared with 0 h/d for patients who received best medical therapy (between group mean difference, 4.5 h/d [95% CI, 3.7-5.4 h/d]; P < .001). Motor function improved significantly (P < .001) with deep brain stimulation vs best medical therapy, such that 71% of deep brain stimulation patients and 32% of best medical therapy patients experienced clinically meaningful motor function improvements (> or = 5 points). Compared with the best medical therapy group, the deep brain stimulation group experienced significant improvements in the summary measure of quality of life and on 7 of 8 PD quality-of-life scores (P < .001). Neurocognitive testing revealed small decrements in some areas of information processing for patients receiving deep brain stimulation vs best medical therapy. At least 1 serious adverse event occurred in 49 deep brain stimulation patients and 15 best medical therapy patients (P < .001), including 39 adverse events related to the surgical procedure and 1 death secondary to cerebral hemorrhage.

CONCLUSION

In this randomized controlled trial of patients with advanced PD, deep brain stimulation was more effective than best medical therapy in improving on time without troubling dyskinesias, motor function, and quality of life at 6 months, but was associated with an increased risk of serious adverse events.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00056563.

Globus pallidus stimulation improves both motor and nonmotor aspects of quality of life in advanced Parkinson's disease

Our purpose was to measure the change in quality of life (QoL) following deep brain stimulation of the globus pallidus interna (GPi-DBS) in advanced Parkinson 's disease (PD), and identifies any associations with changes in motor features of the disease. Eleven patients (age range 54-69 years, 2 women) underwent GPi-DBS (4 unilateral, 7 bilateral). Outcome measures included assessment of PD-specific QoL (mean 8 months postsurgery) using the PDQ-39 questionnaire, and standard motor assessments. Off-period UPDRS III motor scores fell by (43 +/- 8)% (mean +/- SEM). Dyskinesia severity was reduced on the abnormal involuntary movement scale by (80 +/- 3)% and UPDRS IVa by (58 +/- 8)%. QoL as assessed by the PDQ39SI improved by (30 +/- 5)%, with significant improvements in mobility, activities of daily living, bodily discomfort, emotional wellbeing, communication, and cognitions subscales. Bilateral and unilateral groups demonstrated equivalent PDQ39SI improvement. QoL improvement was highly correlated with dyskinesia reduction but not reduction in UPDRS score or age at surgery. GPi-DBS markedly improves QoL in advanced PD. The impacts are broad and improve QoL domains not directly affected by the motor symptoms of the disease. Reduced dyskinesia plays a major role in the improvement of QoL in GPi-DBS treated patients.

Effect of medical and surgical interventions on health-related quality of life in Parkinson's disease

Motor-related parameters are the standard outcome parameters for treatment interventions. Nonetheless, subjective appraisals about the consequences of treatment on health-related quality of life (HRQoL) are meanwhile established and may uncover important aspects of interventions. We have reviewed the literature with a defined search strategy and collected 61 clinical trials, which have used HRQoL as a planned outcome parameter. The articles were rated similarly as for the Task Force report of the Movement Disorder Society on interventions for Parkinson's disease (PD), but the relevant outcome parameter was HRQoL. We found that unilateral pallidotomy, deep brain stimulation of the subthalamic nucleus, and rasagiline are efficacious to improve the HRQoL of PD patients. For many other interventions, the efficacy to improve HRQoL in the PD setting cannot be considered to be proven so far. HRQoL should be part of future trial designs and more research is necessary to understand the determinants of QoL in PD.

Globus pallidus stimulation in advanced Parkinson’s disease

Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has become an accepted therapeutic modality in selected Parkinson's disease (PD) patients with severe levodopa-induced dyskinesias (LID) and on-off motor fluctuations. In comparison to subthalamic nucleus DBS there is a paucity of data on GPi DBS outcomes. We present our experience with a group of 20 PD patients (9 unilateral, 11 bilateral) who underwent GPi stimulation. PD motor symptoms were assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) part III scores and subscores, and dyskinesia using the Abnormal Involuntary Movement Scale (AIMS), UPDRS part IVa, and clinical global impression (CGI). At mean follow-up time of 7 months, bilateral stimulation reduced off-period motor scores by a mean of 46% and on-period motor scores by 18%. Unilateral stimulation reduced off-period motor scores by 18%. Dyskinesia severity was reduced by 76%, which was maintained after a mean follow-up time of 35 months. Antiparkinsonian medication dosage was unchanged. No major adverse effects were seen. Unilateral and bilateral GPi DBS provides lasting benefit in PD patients with severe LID. Beneficial effects on off-period motor symptoms are greater with bilateral stimulation; however, with maintenance of dopaminergic medication, unilateral procedures can also provide important and sustained benefits.

Quality of life and related concepts in Parkinson's disease: A systematic review

Several studies have investigated the quality of life (QOL) of patients with Parkinson's disease (PD). The purpose of this study was to review the conceptual and methodological quality of quality of life (QOL) studies among patients with PD and to identify factors associated with poor (HR)QOL. Computerized bibliographic databases were screened for publications from 1960 to January 2007. According to a list of predefined criteria, the methodological quality of the 61 studies, was moderate. The term 'QOL' was often used inappropriately. In fact, almost all studies in this review actually assessed health status (HS) instead of QOL. The functioning of patients with PD on physical, social, and emotional domains is affected by PD. Their HS seems to be lower when compared to healthy persons or patients with other chronic diseases. HS studies augment the insight in self-perceived functioning. Therefore, HS is conceived as a valuable construct. However, QOL is also an important factor in health care. Attention towards QOL is needed in order to draw valid conclusions regarding a person's subjective experience of well-being in a broad sense. In order to accomplish this, future studies should apply the QOL concept with more rigor, should use an adequate operational definition, and should employ sound measures.

Putting Wilson and Cleary to the test: analysis of a HRQOL conceptual model using structural equation modeling

Wilson and Cleary (1995) proposed a conceptual model of health-related quality of life (HRQOL) that integrates both biological and psychological aspects of health outcomes. There are five different levels in their model, namely, physiological factors, symptom status, functional health, general health perceptions, and overall quality of life. Their model has been widely applied to different populations, including patients living with cancer, Parkinson's disease, arthritis, and HIV+/AIDS. However, their conceptual model has only been partially examined. That is, the five major concepts have not been examined simultaneously. Using structural equation modeling (SEM), the Wilson and Cleary HRQOL model was validated in patients living with HIV from the AIDS Time-Oriented Health Outcomes Study. The results showed that the HRQOL model fit the data adequately, and the relationships between the constructs were all significant (at p<0.05 level). Based on the modification indexes, an alternative model linking symptom status directly with general health perceptions and overall quality of life was specified. Implication and limitation of the findings are discussed.

Impact of Fatigue in Parkinson’s Disease: The Fatigue Impact Scale for Daily Use (D-FIS)

The Fatigue Impact Scale for Daily Use (D-FIS) was used in a cross-sectional study including 142 consecutive Parkinson's disease (PD) patients. Usual clinical measures for PD, the Montgomery-Asberg Depression Rating Scale and the Parkinson's Disease Questionnaire-8 items were applied. In addition to the D-FIS, patients with fatigue (67.6%, PWF) completed the Multidimensional Fatigue Inventory (MFI), a visual analogue scale for fatigue (VAS-F) and a Global Perception of Fatigue scale (GPF). Relevant psychometric D-FIS results were: floor effect = 4.2%; ceiling effect = 1.1%; skewness = 0.44; item homogeneity = 0.63; Cronbach's alpha = 0.93; item-total correlation = 0.68 (item 1)-0.82 (item 8); standard error of measurement = 2.15; convergent validity with other fatigue measures = 0.54 [GPF]-0.62 [VAS-F] (p<0.001). In a multiple linear regression model, fatigue, depression, and disability independently influenced HRQoL, as measured by the PDQ-8. Patients on amantadine had lower prevalence of fatigue. In PD, D-FIS is a consistent and valid measure for fatigue, a frequent symptom previously found to impair patients' HRQoL. Fatigue was also linked to depression and disability in this study.

Deep brain stimulation: Preoperative issues

Numerous factors need to be taken into account in deciding whether a patient with Parkinson's disease (PD) is a candidate for deep brain stimulation. Patient-related personal factors including age and the presence of other comorbid disorders need to be considered. Neuropsychological and neuropsychiatric concerns relate both to the presurgical status of the patient and to the potential for surgery to result in new problems postoperatively. A number of factors related to the underlying PD need to be considered, including the specific parkinsonian motor indications (e.g., tremor, bradykinesia, gait dysfunction), previous medical therapies, including benefit from current therapy and adverse effects, and past surgical treatments. Definable causes of Parkinsonism, particularly atypical Parkinsonisms, should be considered. Finally, methods of evaluating outcomes should be defined and formalized. This is a report from the Consensus on Deep Brain Stimulation for Parkinson's Disease, a project commissioned by the Congress of Neurological Surgeons and the Movement Disorder Society (MDS). The report has been endorsed by the Scientific Issues Committee of the MDS and the American Society of Stereotactic and Functional Neurosurgery. It outlines answers to a series of questions developed to address all aspects of deep brain stimulation preoperative decision-making.

A Review of the Health-Related Quality of Life and Economic Impact of Parkinson??s Disease

Parkinson's disease (PD) is a chronic, neurodegenerative disease that places a substantial burden on patients, their families and carers, as well as on society as a whole. PD can severely affect the health-related quality of life (HR-QOL) of both patients and their carers and, as the disease progresses, HR-QOL deteriorates. This review aims to critically evaluate the literature on a number of important aspects that influence HR-QOL in relation to PD. Factors associated with a negative impact and ways to improve HR-QOL are highlighted, and tools for HR-QOL assessment reviewed. The economic impact of PD and related cost-effectiveness studies are also reviewed. Over the course of the disease, patients with PD experience changes in their HR-QOL that are affected by factors such as depression, motor complications, education and surgery. However, a lack of uniformity in the choice of HR-QOL tools used in studies makes comparison of results difficult. Research on motor fluctuations and dyskinesias has shown conflicting results, whereas it is clear from the available data that depression needs to be more clearly recognised and treated. Inequality in the numbers of men and women receiving surgery still needs to be addressed and, again, in this area there is a lack of uniformity with respect to assessment for surgery. Education programmes have been shown to be successful in improving HR-QOL, although more research is needed about how to introduce such programmes to all PD patients. In particular, there has been little detailed research into young-onset PD and juvenile patients to assess the true impact of the disease on their HR-QOL. The literature has also shown that PD can affect the HR-QOL of the carer, which may have a 'knock-on' effect for the patient. The HR-QOL of carers needs more attention because these individuals can significantly reduce the burden that would otherwise fall on the health services in terms of cost and care. Research shows that the economic costs of PD are high, particularly for patients in advanced stages of the disease and those with motor complications. Although carer burden is a major source of costs, this is not factored into cost-effectiveness analyses. Furthermore, because too few studies use quality-adjusted life years as their health outcome, particularly in studies of the costs of surgery, comparison of costs of treatments is difficult. The review highlights the need for HR-QOL tools such as the EuroQol-5D to be used together with disease-specific tools to provide the most comprehensive picture of the costs and impact of PD.A recent upsurge in published literature on PD resulting from increased interest in HR-QOL issues has led to an at times overwhelming amount of new information. The present review assembles the most important points relating to HR-QOL in PD raised in the literature, adds value to previously covered issues, and examines areas of HR-QOL in PD that have not previously been reviewed, such as education, carer burden and surgery, highlighting where more research is warranted.

Deep brain stimulation in Parkinson disease: a metaanalysis of patient outcomes

Object. Deep brain stimulation (DBS) to treat advanced Parkinson disease (PD) has been focused on one of two anatomical targets: the subthalamic nucleus (STN) and the globus pallidus internus (GPI). Authors of more than 65 articles have reported on bilateral DBS outcomes. With one exception, these studies involved pre- and postintervention comparisons of a single target. Despite the paucity of data directly comparing STN and GPI DBS, many clinicians already consider the STN to be the preferred target site. In this study the authors conducted a metaanalysis of the existing literature on patient outcomes following DBS of the STN and the GPI.

Methods. This metaanalysis includes 31 STN and 14 GPI studies. Motor function improved significantly following stimulation (54% in patients whose STN was targeted and 40% in those whose GPI was stimulated), with effect sizes (ESs) of 2.59 and 2.04, respectively. After controlling for participant and study characteristics, patients who had undergone either STN or GPI DBS experienced comparable improved motor function following surgery (p = 0.094). The performance of activities of daily living improved significantly in patients with either target (40%). Medication requirements were significantly reduced following stimulation of the STN (ES = 1.51) but did not change when the GPI was stimulated (ES = −0.02).

Conclusions. In this analysis the authors highlight the need for uniform, detailed reporting of comprehensive motor and nonmotor DBS outcomes at multiple time points and for a randomized trial of bilateral STN and GPI DBS.

The effect of deep brain stimulation on quality of life in movement disorders

Deep brain stimulation (DBS) is a viable treatment alternative for patients with Parkinson's disease (PD), essential tremor (ET), dystonia, and cerebellar outflow tremors. When poorly controlled, these disorders have detrimental effects on the patient's health related quality of life (HRQoL). Instruments that measure HRQoL are useful tools to assess burden of disease and the impact of therapeutic interventions on activities of daily living, employment, and other functions. We systematically and critically reviewed the literature on the effects of DBS on HRQoL in PD, ET, dystonia, and cerebellar outflow tremor related to multiple sclerosis.

Psychiatric aspects of Parkinson's disease--an update

In patients with Parkinson's disease (PD) disturbances of mental state constitute some of the most difficult treatment challenges of advanced disease, often limiting effective treatment of motor symptoms and leading to increased disability and poor quality of life. This article provides an update on the current knowledge of these complications and the use of old and new drugs in their management. Mental state alterations in PD include depression, anxiety, cognitive impairment, apathy, and treatment-related psychiatric symptoms. The latter range from vivid dreams and hallucinations to delusions, manic symptoms, hypersexuality, dopamine dysregulation syndrome and delirium. While some of these symptoms may be alleviated by anti-parkinsonian medication, especially if they are off-period related, treatment-related phenomena are usually exacerbated by increasing the number or dosage of antiparkinsonian drugs. Elimination of exacerbating factors and simplification of drug regimes are the first and most important steps in improvement of such symptoms. However, the advent of atypical antipsychotics such as clozapine has dramatically helped the management of treatment-related psychiatric complications in PD. In patients with dementia associated with PD cognitive functioning and behavioural problems appear to respond to cholinesterase inhibitors, such as rivastigmine or donepezil. Depression is a common problem in early as well as advanced PD, and selective serotonin reuptake inhibitors, reboxetine, and tricyclic antidepressants have been reported to be effective and well tolerated antidepressants. Randomised, controlled studies are required to assess the differential efficacy and tolerability of antidepressants in patients with PD, including the newer antidepressants with serotonergic and noradrenergic properties.

Efficacy of deep brain stimulation of the subthalamic nucleus in Parkinson's disease 4 years after surgery: double blind and open label evaluation

OBJECTIVE

To evaluate the long term (4 years) efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease.

METHODS

We performed a double blind crossover evaluation of the efficacy of DBS of the STN in the "off" medication condition in 10 patients with Parkinson's disease. Assessments included the Unified Parkinson's Disease Rating Scale (UPDRS) part III (motor) and two timed tests (arm tapping and walking). Open evaluation of the effect of stimulation in the off and on drug states preoperatively and at 1 and 4 years postoperatively was also conducted. The latter assessment included the UPDRS parts II (activities of daily living) and III (dyskinesia scale and global assessment) as judged by the patient and examiner. The mean amount of levodopa daily dose at base line, 1 year, and 4 years after surgery was compared.

RESULTS

A significant (p<0.04) effect of stimulation was observed in the overall group regarding both the UPDRS motor and the timed tests. Open evaluation also showed a significant benefit of STN DBS with respect to preoperative assessment in both the motor and activities of daily living scales, dyskinesia scale, and in global assessment. Levodopa daily dose was reduced by 48% and 50% at 1 and 4 years, respectively. There was no difference between the 1 and 4 years evaluations in any of the parameters evaluated. Complications due to stimulation were minor.

CONCLUSIONS

DBS of the STN provides a significant and persistent anti-parkinsonian effect in advanced Parkinson's disease 4 years after surgery.

Neuropsychiatric complications of medical and surgical therapies for Parkinson's disease

This review deals with the range of neuropsychiatric problems that may arise from the use of medical and surgical therapies in the treatment of Parkinson's disease. As new approaches emerge, these problems are diversifying. Well-recognized drug-related complications include hallucinations and psychosis and the so-called dopamine-dysregulation syndrome. The etiology of these problems has not been fully established and is not clearly dose related, while the management can be difficult and needs to be tailored to the individual patient. Cholinergic and dopaminergic drugs may both influence cognitive function. The development of pharmacogenetics could improve the therapeutic ratio of medical approaches to PD in the future. The literature relating to the neuropsychiatric issues complicating the surgical treatment of Parkinson's disease is more recent and frequently suffers from methodological problems, lack of a systematic approach, and adequate patient follow-up. The emergence of neuropsychiatric problems in association with surgery has shed new light upon the pathophysiological mechanisms underpinning these symptoms. Depression, hypomania, euphoria, mirth, and hypersexuality have all been described following deep brain stimulation procedures, although most studies have concentrated upon the depressive features. Anxiety has been described only rarely to date. Fortunately, permanent cognitive complications appear to be rare. The optimal management approach for surgically related neuropsychiatric problems is unknown at present. Prospective multicenter studies would contribute significantly to resolving this therapeutic uncertainty.

Improvement in quality of life in patients with advanced Parkinson's disease following bilateral deep-brain stimulation in subthalamic nucleus

In this article we investigate the changes observed in the scales that quantify the quality of life (PDQ-39) in patients that have already completed 1 and 2 years of bilateral subthalamic stimulation (DBS-STN). Fourteen patients were evaluated 1 year after DBS-STN; the evaluation was repeated on 11 of them, 2 years after surgery. All of them suffered from Parkinson's disease with a 14.3 (+/-5.7) years history of motor complications. Patients were selected according to CAPSIT criteria. All of them were implanted bilateral electrodes in the subthalamic nucleus. The parameters applied were UPDRS II, UPDRS III, PDQ-39, and the scale of quality of life for caregivers (SQLC). Scorings in motor scales (UPDRS III) improved 45% in relation to the first year, and 48% in relation to the second year (P < 0.001). Patient's quality of life (PDQ-39 summary index) improvement was 62% 2 years after surgery (P < 0.001), and caregivers' quality of life improvement was 68% (P = 0.002) by the same time. DBS-STN is a therapy that efficiently improves the quality of life of selected patients with Parkinson's disease. This improvement is still present 2 years after surgery and has a positive impact on caregivers quality of life.

A novel quality of life instrument for deep brain stimulation in movement disorders

OBJECTIVE

To develop a short instrument to examine quality of life (QoL) which specifically addresses patients with movement disorders treated by deep brain stimulation (DBS).

DESIGN

The instrument was developed within an existing concept of a modular questionnaire (questions on life satisfaction: "general life satisfaction" QLS(M)-A, and "satisfaction with health" QLS(M)-G), in which each item is weighted according to its relative importance to the individual.

METHODS

Items were generated by interviews with 20 DBS patients, followed by item reduction and scale generation, factor analysis to determine relevant and final questionnaire items, estimation of reliability, and validation based on the medical outcome study 36 item short form health survey (SF-36) and the EuroQol (EQ-5D) (data from 152 patients with Parkinson's disease, essential tremor, or idiopathic torsion dystonia, including 75 patients with DBS).

RESULTS

Initial questionnaires were reduced to 12 items for a "movement disorder module" (QLS(M)-MD), and five items for a "deep brain stimulation module" (QLS(M)-DBS). Psychometric analysis revealed Cronbach's alpha values of of 0.87 and 0.73, and satisfactory correlation coefficients for convergent validity with SF-36 and EQ-5D.

CONCLUSIONS

QLS(M)-MD and QLS(M)-DBS can evaluate quality of life aspects of DBS in movement disorders. Psychometric evaluation showed the questionnaires to be reliable, valid, and well accepted by the patients.

A waitlist control-group study of cognitive, mood, and quality of life outcome after posteroventral pallidotomy in Parkinson disease

OBJECT

The aim of this study was to examine neuropsychological outcome from unilateral posteroventral pallidotomy (PVP) in Parkinson disease while controlling for confounding factors such as test practice and disease progression.

METHODS

Participants underwent baseline and 2-month follow-up assessments of cognition, quality of life, mood, and motor functioning. The surgery group (22 patients) underwent PVP (15 left, seven right) after baseline assessment. The waitlist group (14 patients) underwent PVP after follow up. At follow up, the left PVP group exhibited a decline on verbal measures of learning, fluency, working memory, and speeded color naming. The incidence of significant decline on these measures after left PVP ranged from 50 to 86%. The right PVP group did not exhibit a significant cognitive decline, but fluency did decline in 71% of patients who underwent right PVP. Participants who underwent PVP reported better bodily pain and social functioning at follow up than participants in the waitlist group. Improved bodily pain was evident for 62% of the surgery group, and social functioning improved for 19%. Surgery did not alter reported physical functioning or mood. Dyskinesia improved after surgery, but there were no improvements in "on-state" manual dexterity or handwriting.

CONCLUSIONS

Most patients who underwent left PVP exhibited declines in learning, fluency, working memory, and speeded color naming. Accounting for retesting effects altered the magnitude of these declines by up to one quarter of a standard deviation, but did not increase the breadth of postsurgical neuropsychological decline beyond that typically reported in the literature. It was found that PVP improved dyskinesia, bodily pain, and social functioning, but did not lead to improvement on other objective and self-reported measures of motor functioning.

Pulse width is associated with cognitive decline after thalamic stimulation for essential tremor

The present study sought to identify predictors of cognitive decline after thalamic deep brain stimulation (DBS) for essential tremor (ET). Twenty-seven patients (55%) with ET demonstrated mild cognitive decrements relative to pre-surgical baseline (ET-D), whereas 22 patients (45%) were classified as neuropsychologically stable (ET-S). The ET-D and ET-S groups were comparable in terms of baseline demographic, disease, and neuropsychological characteristics, as well as post-surgical motor outcomes. However, the ET-D group had significantly higher pulse width (PW) stimulator settings, and a greater proportion of ET-D than ET-S patients underwent left in comparison to right thalamic stimulation. A subsequent step-wise discriminant function analysis revealed that disease onset after age 37 years and higher PW settings (>or=120 micros) were the strongest predictors of post-surgical cognitive decline in this sample. Findings indicate that although relatively higher PW settings might afford optimal tremor control in some patients, the corresponding risk of mild, probably often subclinical, cognitive morbidity must be weighed accordingly.

Neuropsychological and quality of life outcomes 12 months after unilateral thalamic stimulation for essential tremor

OBJECTIVES

To evaluate the one year cognitive, mood state, and quality of life (QoL) outcomes of unilateral thalamic deep brain stimulation (DBS) for essential tremor (ET).

METHODS

40 patients diagnosed with ET completed comprehensive neuropsychological assessments about one month before and three and 12 months after DBS electrode implantation. Data were subjected to multivariate analyses, and significant results were further analysed using univariate techniques.

RESULTS

Analyses revealed statistically significant improvements on a cognitive screening measure and in aspects of fine visuomotor and visuoperceptual functions, verbal memory, mood state, and QoL. No group-wise declines in cognition were observed, but more patients showed declines than improvements on language and visual memory tests. Semantic verbal fluency declined significantly in four (10%) of the patients. In these four patients, diminished lexical verbal fluency was present at baseline.

CONCLUSION

Cognitive, mood, and QoL outcomes after one year of DBS for ET are favourable; there were no overall deleterious effects on cognition, and DBS was accompanied by a significant reduction in anxiety and improvements in quality of life. However, preoperative verbal fluency diminution may predispose to further fluency declines after DBS.

Declines in switching underlie verbal fluency changes after unilateral pallidal surgery in Parkinson's disease

Declines in verbal fluency are consistently reported in patients with Parkinson's disease (PD) after pallidal surgery. In the present study, the clustering and switching components of semantic or category fluency (oral naming of items obtainable in supermarkets) were examined at baseline and four months after unilateral deep brain stimulation or pallidotomy in 45 patients with PD (30 left, 15 right pallidal surgery). Post-operative declines were observed for supermarket fluency total score and switching, but not for average cluster size. These findings support the proposal that semantic fluency decrements after pallidal surgery reflect a disruption of frontal-basal ganglia circuits mediating efficient shifting between semantic categories, or perhaps efficient access to categories, rather than a degradation of semantic stores.

Long-term follow-up of globus pallidus chronic stimulation in advanced Parkinson's disease

To assess the long-term follow-up of the globus pallidus internus (GPi) stimulation, six patients were evaluated every year by using the Unified Parkinson's Disease Rating Scale (UPDRS). Three years postoperatively, GPi stimulation led to a significant improvement of dyskinesia severity (50%, P = 0.05) and activities of daily living (subscore of quality of life scale, 9%, P = 0.05). However, the improvement induced by chronic pallidal stimulation on the mean daily duration in the off state was lost at the last assessment.

Neuropsychological sequelae of subthalamic nucleus deep brain stimulation in Parkinson's disease: a critical review

Neuropsychologists are increasingly involved in surgical candidacy evaluations and postoperative neurobehavioral assessments of patients with movement disorders, most notably those with Parkinson's disease (PD). We review here the initial studies regarding neuropsychological outcomes of deep brain stimulation (DBS) within the subthalamic nucleus (STN) for treatment of PD. Overall, these initial investigations provide preliminary support for the cognitive and neurobehavioral safety of STN DBS. Improvements in self-reported symptoms of depression and diminished verbal fluency were the most common findings, whereas changes in global cognitive abilities, memory, attention, and frontal/executive functions were inconsistent and most often described as nominal and/or transient. The generalizability of this literature is hindered by several methodological limitations, including small samples and the absence of appropriate control participants. The clinical and theoretical implications of these initial studies are highlighted and recommendations are offered to guide future research.

Long-term pallidal deep brain stimulation in patients with advanced Parkinson disease: 1-year follow-up study

OBJECT

The goal of this study was to investigate the efficacy of long-term deep brain stimulation (DBS) of the posteroventral lateral globus pallidus internus (GPi) accomplished using a single-contact monopolar electrode in patients with advanced Parkinson disease (PD).

METHODS

Sixteen patients suffering from severe PD and levodopa-induced side effects such as dyskinesias and on-off fluctuations were enrolled in a prospective study protocol. There were six women and 10 men and their mean age at surgery was 65 years. All patients underwent implantation of a monopolar electrode in the posteroventral lateral GPi. Initially, nine patients received unilateral stimulation. Three of these patients underwent contralateral surgery at a later time. Ten patients received bilateral stimulation (contemporaneous bilateral surgery was performed in seven patients and staged bilateral surgery in the three patients who had received unilateral stimulation initially). Formal assessments were performed during both off-medication and on-medication (levodopa) periods preoperatively, and at 3 and 12 months postoperatively. There were no serious complications related to surgery or to DBS. Two transient adverse events occurred: in one patient a small pallidal hematoma developed, resulting in a prolonged micropallidotomy effect, and in another patient a subcutaneous hemorrhage occurred at the site of the pacemaker. In patients who received unilateral DBS, the Unified Parkinson's Disease Rating Scale activities of daily living (ADL) score during the off-levodopa period decreased from 30.8 at baseline to 20.4 at 3 months (34% improvement) and 20.6 at 12 months (33% improvement) postoperatively. The motor score during the off period improved from 57.2 at baseline to 35.2 at 3 months (38% improvement) and 35.3 at 12 months (38% improvement) postoperatively. Bilateral DBS resulted in a reduction in the ADL score during the off period from 34.9 at baseline to 22.3 at 3 months (36% improvement) and 22.9 at 12 months (34% improvement). The motor score for the off period changed from 63.4 at baseline to 40.3 at 3 months (36% improvement) and 37.5 at 12 months (41% improvement). In addition, there were significant improvements in patients' symptoms during the on period and in on-off motor fluctuations.

CONCLUSIONS

Pallidal DBS accomplished using a monopolar electrode is a safe and effective procedure for treatment of advanced PD. Compared with pallidotomy, the advantages of pallidal DBS lie in its reversibility and the option to perform bilateral surgery in one session. Comparative studies in which DBS is applied to other targets are needed.

Health-related quality of life in patients with advanced Parkinson's disease treated with deep brain stimulation of the subthalamic nuclei

Parkinson's disease (PD) is a progressive neurodegenerative disorder for which there is as yet no cure. It affects many aspects of patients' lives, only some of which can be monitored by available clinical rating scales. In the past decade, there has been a new emphasis on the use of health-related quality of life (HRQOL) measures to describe patient response to treatment. We describe patient-reported HRQOL in subjects who underwent bilateral deep brain stimulation (DBS) of the subthalamic nuclei (STN) for the treatment of PD, compared with a similar group of subjects who did not receive surgical treatment. A consecutive series of patients (n = 11) with advanced idiopathic PD were treated with DBS of the STN. This surgically treated group was compared prospectively with a similar group of patients (n =13) awaiting surgery. Self-reported HRQOL, measured by the Parkinson's Disease Questionnaire (PDQ-39) was evaluated at three time periods T(0), T(3), and T(6). The surgery group was evaluated according to the Unified Parkinson's Disease Rating Sale (UPDRS) before (T(0)), 3 (T(3)), and 6 months (T(6)) after surgery. HRQOL, UPDRS part II and III, duration of off periods, and dyskinesias improved significantly from T(0) to T(3) and from T(0) to T(6) for the surgery group but not for the nonsurgery group. Ten of the 11 patients treated with DBS of the STN reported a lower summary score (indicating better HRQOL) 6 months after surgery. The results of this prospective controlled study suggest that patients with advanced idiopathic PD treated with DBS of the STN obtain significant improvements in patient reported HRQOL and in clinical outcomes 3 and 6 months after surgery.

Bilateral subthalamic nucleus stimulation and quality of life in advanced Parkinson's disease

We examined the impact of the subthalamic nuclei (STN) deep brain stimulation (DBS) on the health-related quality of life (QoL) of patients with advanced Parkinson's disease (PD). Seventeen consecutive patients with refractory motor fluctuations and dyskinesia were included in the study (mean age, 60.9 +/- 7.7 years [range, 43-74 years]; disease duration, 16.4 +/- 8.5 years [range, 7-38 years]; mean off-medication Hoehn and Yahr stage, 4.23 +/- 0.66 [range, 2.5-5]). Each patient's assessment was carried out using common rating scales, following the Core Assessment Program for Intracerebral Transplantation (CAPIT) protocol. Dyskinesia and emotional state were evaluated through the Abnormal Involuntary Movement Scale (AIMS) and the Hospital Anxiety and Depression Scale (HAD). QoL was assessed by means of the Parkinson's Disease Questionnaire Spanish version (PDQ-39). Significant benefit was obtained in the motor manifestations and complications of disease, as well as in the functional state and mood (P < 0.001). Some QoL dimensions (mobility and activities of daily living) and the PDQ-39 Summary Index (PDQ-39SI) showed a significant improvement (P < 0.001). Benefit was modest (P < 0.05) for three other domains (emotional well-being, stigma, bodily discomfort) and nil for the rest. There was no correlation between the change obtained in the QoL (PDQ-39SI) and in the other variables. As measured by the PDQ-39, STN-DBS significantly improves important aspects of QoL in patients with advanced PD.

Quality of life outcomes following surgical treatment of Parkinson's disease

We assessed the impact of surgical treatment of Parkinson's disease on quality of life using generic quality of life instruments and utility scores. The Medical Outcomes Study short form health survey SF-36 and Parkinson's Disease Questionnaire PDQ-39 were used before and 3-6 months after surgery to assess quality of life, and the results were converted into utility valuations. Ninety-seven patients were studied; 33 underwent unilateral thalamotomy, 33 unilateral pallidotomy, 20 bilateral pallidotomy, six subthalamic nucleus (STN) lesions, four mixed lesions, and in one case bilateral STN stimulation. All dimensions of the SF-36 except role mental and mental health showed statistically significant improvement following surgery. The PDQ-39 recorded significant improvements in the mobility, stigma, and bodily discomfort dimensions. The rating scale and time trade-off scales showed statistically significant gains in utility of 8% and 3%, respectively. Gains were particularly marked in the bilateral pallidotomy group. Differences in patient characteristics and selection made direct comparisons between procedures unreliable. Quality of life in patients with advanced Parkinson's disease is amenable to measurement; such measurement provides tentative evidence of significant gains in quality of life following some neurosurgical procedures.

Health-related quality of life and healthcare utilisation in patients with Parkinson's disease: impact of motor fluctuations and dyskinesias

Idiopathic Parkinson's disease (PD) is a common chronic progressive neuro-degenerative disorder associated with the progressive loss of dopaminergic neurons in the substantia nigra. The natural course of the disease may lead to severe disability despite a variety of pharmacological and surgical treatment options. Levodopa is still the most effective symptomatic treatment for PD; however, long term use can cause a number of adverse effects including motor complications, nausea and vomiting, postural hypotension and changes in mental status. The onset of motor complications marks a crucial point in the management of PD. They may present as changes between akinetic and mobile phases (motor fluctuations) or as abnormal involuntary movements (dyskinesias). After levodopa treatment for 3 to 5 years, motor complications occur in approximately 50% of patients, and after 10 years in >80% of patients. Treatment options have recently expanded as new drugs have been licensed and surgical procedures refined. Patients with motor complications present a demanding task in disease management, and often multiple drugs and high dosages are necessary to achieve only suboptimal control, resulting in increased healthcare utilisation. Costs increase considerably in patients with motor fluctuations and dyskinesias compared with patients without these symptoms. In a French study, 6-month direct medical costs per patient increased from 1648 euros (EUR) to EUR3028 in patients without and with motor fluctuations, respectively. In a recent French study a significant difference in monthly direct medical costs was found in patients with and without dyskinesias (EUR560 vs 170). Unfortunately, no data are available on the effect of motor complications on indirect costs. Several studies have shown that health-related quality of life (HR-QOL) is reduced when motor fluctuations occur. This may also be true of dyskinesias, but because of the limited number of studies a definite conclusion is not yet possible. Recently, surgical treatment options have been used to deal with advanced PD and late stage complications. Although their effect on motor complications and HR-QOL is well documented, they result in increased costs (total medical cost: EUR28920) compared with drug treatment alone and are increasingly restricted by healthcare providers. The purpose of this article is to review the available data from pharmacotherapeutic. surgical and economic studies on HR-QOL and healthcare expenditure in patients with PD, with a major focus on the impact of motor fluctuations and dyskinesias.

Cognitive outcome following staged bilateral pallidal stimulation for the treatment of Parkinson's disease

As neurosurgical treatment of parkinsonian symptoms has become increasingly popular, concern about the cognitive morbidity which may result from such interventions has risen proportionately. Previous reports of cognitive difficulties associated with pallidotomy and thalamotomy, especially in bilateral cases, have provided the impetus for research into chronic electrical deep brain stimulation procedures which are believed to be safer than ablation. Given the lack of neurobehavioral research following bilateral deep brain stimulation procedures, this preliminary study of six Parkinson's disease patients undergoing staged bilateral pallidal stimulation was undertaken. A battery of tests assessing attention, executive function, visuomotor coordination, language, visuoperceptual function, learning memory and mood revealed no significant change in overall level of cognitive functioning after either unilateral or bilateral pallidal deep brain stimulation. No significant declines were observed about three months following bilateral stimulation, and in fact, significant gains in delayed recall and relief of anxiety symptoms were noted. It was concluded from this preliminary data that bilateral pallidal stimulation for the treatment of Parkinson's disease, at least in the absence of operative complications, offers a cognitively safe alternative to ablation.