Neurosurgery in Parkinson disease: A distressed mind in a repaired body?

Patients' expectations in subthalamic nucleus deep brain stimulation surgery for Parkinson disease

OBJECTIVE

Subthalamic nucleus (STN) deep brain stimulation (DBS) is an established treatment for patients with advanced Parkinson disease. However, some patients feel less satisfied with the outcome of surgery. We sought to study the relationship between expectations, satisfaction, and outcome in STN DBS for Parkinson disease.

METHODS

Twenty-two consecutive patients undergoing STN DBS completed a modified 39-item Parkinson disease questionnaire (PDQ-39) preoperatively and 6 months postoperatively. A satisfaction questionnaire accompanied the postoperative questionnaire.

RESULTS

Patients expected a significant improvement from surgery preoperatively: preoperative score (median PDQ-39 summary score [interquartile range]): 37.0 (9.5), expected postoperative score: 13.0 (8.0), P < 0.001. Patients improved after surgery (preoperative score 39.0 [11.5], postoperative score 25.0 [14.3], P = 0.003), although there was a substantial disparity between the expected change (24.0 [15.0]) and actual change (14.0 [22.5]), P = 0.008. However, most patients felt that surgery fulfilled their expectations (mean score on a 0%-100% visual analog scale); (75.3 ± 17.8) and were satisfied (73.3 ± 25.3). Satisfaction correlated with fulfillment of expectations (r = 0.910, P < 0.001) but not with quantitative changes in PDQ-39 scores.

CONCLUSIONS

Addressing patients' expectations both preoperatively and postoperatively may play an important role in patient satisfaction, and therefore overall success, of STN DBS surgery for Parkinson disease.

Thinking Ahead on Deep Brain Stimulation: An Analysis of the Ethical Implications of a Developing Technology

Deep brain stimulation (DBS) is a developing technology. New generations of DBS technology are already in the pipeline, yet this particular fact has been largely ignored among ethicists interested in DBS. Focusing only on ethical concerns raised by the current DBS technology is, albeit necessary, not sufficient. Since current bioethical concerns raised by a specific technology could be quite different from the concerns it will raise a couple of years ahead, an ethical analysis should be sensitive to such alterations, or it could end up with results that soon become dated. The goal of this analysis is to address these changing bioethical concerns, to think ahead on upcoming and future DBS concerns both in terms of a changing technology and changing moral attitudes. By employing the distinction between inherent and noninherent bioethical concerns we identify and make explicit the particular limits and potentials for change within each category, respectively, including how present and upcoming bioethical concerns regarding DBS emerge and become obsolete. Many of the currently identified ethical problems with DBS, such as stimulation-induced mania, are a result of suboptimal technology. These challenges could be addressed by technical advances, while for instance perceptions of an altered body image caused by the mere awareness of having an implant may not. Other concerns will not emerge until the technology has become sophisticated enough for new uses to be realized, such as concerns on DBS for enhancement purposes. As a part of the present analysis, concerns regarding authenticity are used as an example.

Perceptions of symptoms and expectations of advanced therapy for Parkinson's disease: preliminary report of a Patient-Reported Outcome tool for Advanced Parkinson's disease (PRO-APD)

Background

What do patients expect from a treatment? A patient-centred approach to treatment is becoming necessary given the choices for invasive treatments for Parkinson’s disease. Patient’s perceptions of severity and expectations from complex therapies have not been studied. We describe the rationale and concept of developing a Patient-Reported Outcome (PRO) tool to assess perceptions of symptom severity and expectations of therapy. We report preliminary findings from use of the tool, association with clinical factors, and illustrate the potential use in individual patients awaiting therapy.

Methods

Patient symptoms were grouped into four domains, with 8 motor, 7 non-motor, 7 psychological and 4 social questions. For each question, symptom severity was rated on a Likert scale scoring from 0 (no problem) to 7 (perceived as a severe problem). Similarly, the expectation for each symptom to change after therapy was rated on a Likert scale: score −3 (expected to be very much worse) to + 3 (expected to be very much improved).

Results

22 consecutive patients, routinely planned to receive one of Deep Brain Stimulation/Intrajejunal Levodopa Infusion/Apomorphine Infusion therapies, were recruited: 13 male, mean (+/−sd) age: 65.6 (+/−9.5) years, mean (+/−sd) disease duration: 14.3 (+/−5.7) years. Subjective severity scores are reported as mean (+/−sd) / maximum possible score: (i) motor 23.5 (+/−7.5) / 56, (ii) non-motor 15.5 (+/−5.6) / 49, (iii) cognitive - psychological 12.4 (+/−5.8) / 49, (iv) social 9.3 (+/−4.1) / 28. Expectation of change (improvement) scores are reported as mean (+/−sd) / maximum possible score of: (i) motor 14.0 (+/−5.6) / 24, (ii) non-motor 8.5 (+/−4.1) / 21, (iii) cognitive - psychological 7.4 (+/−4.4)/ 21, and (iv) social 5.5 (+/−2.8) / 12. For each domain, Spearman correlation coefficient showed significant associations between severity and expectation within-domain.

Conclusion

This tool (PRO-APD) provides a description of perceived problem severity and expectation of treatments encompassing a holistic patient-driven view of care. PD patients about to receive complex therapy have moderately high perception of symptom load in multiple domains, and expect substantial improvements in multiple domains. These preliminary findings may be useful in documenting multi-domain symptoms, as well as counseling patients to help them reach realistic expectations and reduce potential dissatisfaction following therapy.

Functional outcome and quality of life in Tourette's syndrome after deep brain stimulation of the posteroventrolateral globus pallidus internus: long-term follow-up

OBJECTIVES

Deep brain stimulation (DBS) for Tourette's syndrome (TS) in various targets has been in the focus for some years. However, there are hardly any data on "psychosocial" outcome after DBS for TS. The aim of the present study therefore was to focus on the functional outcome and "psychosocial changes" in TS patients after DBS.

METHODS

Six patients with treatment-refractory TS underwent GPi-DBS. The Yale Global Tic Severity Scale (YGTSS) was used to evaluate symptomatic outcome. Psychosocial changes were assessed applying the Global Assessment of Functioning Scale (GAF) and the Gilles-de-la-Tourette-Syndrome Quality-of-Life scale (GTS-QOL) with additionally documenting psychosocial changes. Follow-up ranged between 12 and 72 months.

RESULTS

In all symptomatic responders (4 of 6) we found a significant functional improvement (mean GAF increasing from 53.75 (± 7.5) pre-operatively to 83.75 (± 7.5) at last follow-up) along with a positive correlation with the course of GTS-QOL (R(2) = 0.62).

CONCLUSIONS

Treatment success should not only be assessed with the classic "tic-scales", but also with the GAF and GTS-QOL. Although improvement of tics seems to be positively correlated with improved functional outcome, symptomatic improvement may lead to unexpected major psychosocial changes - which both the patient and the clinicians in charge - should be prepared for.

Effects of deep brain stimulation of the subthalamic nucleus on inhibitory and executive control over prepotent responses in Parkinson's disease

Inhibition of inappropriate, habitual or prepotent responses is an essential component of executive control and a cornerstone of self-control. Via the hyperdirect pathway, the subthalamic nucleus (STN) receives inputs from frontal areas involved in inhibition and executive control. Evidence is reviewed from our own work and the literature suggesting that in Parkinson's disease (PD), deep brain stimulation (DBS) of the STN has an impact on executive control during attention-demanding tasks or in situations of conflict when habitual or prepotent responses have to be inhibited. These results support a role for the STN in an inter-related set of processes: switching from automatic to controlled processing, inhibitory and executive control, adjusting response thresholds and influencing speed-accuracy trade-offs. Such STN DBS-induced deficits in inhibitory and executive control may contribute to some of the psychiatric problems experienced by a proportion of operated cases after STN DBS surgery in PD. However, as no direct evidence for such a link is currently available, there is a need to provide direct evidence for such a link between STN DBS-induced deficits in inhibitory and executive control and post-surgical psychiatric complications experienced by operated patients.

Authenticity or autonomy? When deep brain stimulation causes a dilemma

While deep brain stimulation (DBS) for patients with Parkinson's disease has typically raised ethical questions about autonomy, accountability and personal identity, recent research indicates that we need to begin taking into account issues surrounding the patients' feelings of authenticity and alienation as well. In order to bring out the relevance of this dimension to ethical considerations of DBS, I analyse a recent case study of a Dutch patient who, as a result of DBS, faced a dilemma between autonomy and authenticity. This case study is meant to point out the normatively meaningful tension patients under DBS experience between authenticity and autonomy.

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.

Patients' expectations of deep brain stimulation, and subjective perceived outcome related to clinical measures in Parkinson's disease: a mixed-method approach

OBJECTIVE

To study patients' expectations of subthalamic deep brain stimulation (STN-DBS) and their subjective perceived outcome, by using qualitative and quantitative methods in Parkinson's disease (PD).

METHODS

PD patients were prospectively examined before and 3 months after surgery. Semistructured interviews regarding preoperative expectations and postsurgical subjective perceived outcome were conducted. These were analysed using content analysis. For statistical analyses, patients were classified according to their subjective perceived outcome, resulting in three different subjective outcome groups (negative, mixed, positive outcome). The groups were used for multiple comparisons between and within each group regarding motor impairment, quality of life (QoL), neuropsychiatric status and cognitive functioning, using standard instruments. A logistic regression analysis was conducted to find predictors of subjective negative outcome. Receiver operating characteristic curves were used to analyse cut-off scores for predictive tests.

RESULTS

Of the 30 PD patients participating, 8 had a subjective negative outcome, 8 a mixed and 14 a positive outcome. All groups significantly improved in motor functioning. Patients with subjective negative outcome were characterised by preoperative unrealistic expectations, no postsurgical improvement in QoL, and significantly higher presurgical and postsurgical apathy and depression scores. Higher preoperative apathy and depression scores were significant predictors of negative subjective outcome. Cut-off scores for apathy and depression were identified.

CONCLUSIONS

The mixed-method approach proved useful in examining a patient's subjective perception of STN-DBS outcome. Our results show that significant motor improvement does not necessarily lead to a positive subjective outcome. Moreover, PD patients should be screened carefully before surgery regarding apathy and depression. (DRKS-ID: DRKS00003221).

Neurosurgery in Parkinson's disease: Social adjustment, quality of life and coping strategies

Subthalamic nucleus deep brain stimulation has become a standard neurosurgical therapy for advanced Parkinson's disease. Subthalamic nucleus deep brain stimulation can dramatically improve the motor symptoms of carefully selected patients with this disease. Surprisingly, some specific dimensions of quality of life, “psychological” aspects and social adjustment do not always improve, and they could sometimes be even worse. Patients and their families should fully understand that subthalamic nucleus deep brain stimulation can alter the motor status and time is needed to readapt to their new postoperative state and lifestyles. This paper reviews the literatures regarding effects of bilateral subthalamic nucleus deep brain stimulation on social adjustment, quality of life and coping strategies in patients with Parkinson's disease. The findings may help to understand the psychosocial maladjustment and poor improvement in quality of life in some Parkinson's disease patients.

Dopamine agonist withdrawal syndrome: implications for patient care

Dopamine agonists are effective treatments for a variety of indications, including Parkinson's disease and restless legs syndrome, but may have serious side effects, such as orthostatic hypotension, hallucinations, and impulse control disorders (including pathological gambling, compulsive eating, compulsive shopping/buying, and hypersexuality). The most effective way to alleviate these side effects is to taper or discontinue dopamine agonist therapy. A subset of patients who taper a dopamine agonist, however, develop dopamine agonist withdrawal syndrome (DAWS), which has been defined as a severe, stereotyped cluster of physical and psychological symptoms that correlate with dopamine agonist withdrawal in a dose-dependent manner, cause clinically significant distress or social/occupational dysfunction, are refractory to levodopa and other dopaminergic medications, and cannot be accounted for by other clinical factors. The symptoms of DAWS include anxiety, panic attacks, dysphoria, depression, agitation, irritability, suicidal ideation, fatigue, orthostatic hypotension, nausea, vomiting, diaphoresis, generalized pain, and drug cravings. The severity and prognosis of DAWS is highly variable. While some patients have transient symptoms and make a full recovery, others have a protracted withdrawal syndrome lasting for months to years, and therefore may be unwilling or unable to discontinue DA therapy. Impulse control disorders appear to be a major risk factor for DAWS, and are present in virtually all affected patients. Thus, patients who are unable to discontinue dopamine agonist therapy may experience chronic impulse control disorders. At the current time, there are no known effective treatments for DAWS. For this reason, providers are urged to use dopamine agonists judiciously, warn patients about the risks of DAWS prior to the initiation of dopamine agonist therapy, and follow patients closely for withdrawal symptoms during dopamine agonist taper.

Subthalamic stimulation modulates self-estimation of patients with Parkinson's disease and induces risk-seeking behaviour

Patients with Parkinson's disease with deep brain stimulation in the subthalamic nucleus postoperatively often display higher impulsivity and therefore may experience difficulties in social interactions. Here, we examined social interactions of patients with Parkinson's disease with and without deep brain stimulation in the subthalamic nucleus in competitive situations. We hypothesized altered self-estimation and risk-seeking behaviour in this patient group induced by deep brain stimulation in the subthalamic nucleus. To test the hypothesis, an experimental setting was used in which participants performed a calculation task and chose their preferred compensation. Based on their actual calculation performance, more patients with Parkinson's disease with deep brain stimulation chose a competitive tournament compensation. Assuming rational behaviour, this self-selection pattern reflects increased risk tolerance. Since patients who performed in the lowest quartile chose the tournament option, the data suggest that deep brain stimulation in the subthalamic nucleus results in a loss of the correct reference frame against which patients with Parkinson's disease evaluate their performance. The stimulation-induced combination of overestimation of their own performance, increased risk-taking, and preference for competitive environments despite poor performance is likely to impact considerably on the patients' social and work life.

[New indications for deep brain stimulation: ethical criteria for research and therapy]

The applications of deep brain stimulation (DBS) are rapidly increasing and now include a large variety of neurological and psychiatric diseases, such as depression, obsessive compulsive disorders, addiction, Alzheimer's disease, anorexia nervosa and rare movement disorders. These new applications confer a huge therapeutic potential in diseases for which often no treatment exists or which are refractory to existing therapies. This spread of applications, however, implies ethical problems in several domains: clinical use, research and presentation in the media and public. Thus, a systematic ethical analysis is needed to inform and guide this process. In this article we identify ethical problems involved in research and clinical use of novel DBS applications, suggest criteria and distinctions for structuring the ethical analysis, and articulate ethical demands for DBS research of novel applications.

Deep brain stimulation: a return journey from psychiatry to neurology

Deep brain stimulation (DBS) has emerged as an effective neurosurgical tool to treat a range of conditions. Its use in movement disorders such as Parkinson's disease, tremor and dystonia is now well established and has been approved by the National Institute of Clinical Excellence (NICE). The NICE does, however, emphasise the need for a multidisciplinary team to manage these patients. Such a team is traditionally composed of neurologists, neurosurgeons and neuropsychologists. Neuropsychiatrists, however, are increasingly recognised as essential members given many psychiatric considerations that may arise in patients undergoing DBS. Patient selection, assessment of competence to consent and treatment of postoperative psychiatric disease are just a few areas where neuropsychiatric input is invaluable. Partly driven by this close team working and partly based on the early history of DBS for psychiatric disorders, there is increasing interest in re-exploring the potential of neurosurgery to treat patients with psychiatric disease, such as depression and obsessive-compulsive disorder. Although the clinical experience and evidence with DBS in this group of patients are steadily increasing, many questions remain unanswered. Yet, the characteristics of optimal surgical candidates, the best choice of DBS target, the most effective stimulating parameters and the extent of postoperative improvement are not clear for most psychiatric conditions. Further research is therefore required to define how DBS can be best utilised to improve the quality of life of patients with psychiatric disease.

Selecting deep brain stimulation or infusion therapies in advanced Parkinson's disease: an evidence-based review

Motor complications in Parkinson's disease (PD) result from the short half-life and irregular plasma fluctuations of oral levodopa. When strategies of providing more continuous dopaminergic stimulation by adjusting oral medication fail, patients may be candidates for one of three device-aided therapies: deep brain stimulation (DBS), continuous subcutaneous apomorphine infusion, or continuous duodenal/jejunal levodopa/carbidopa pump infusion (DLI). These therapies differ in their invasiveness, side-effect profile, and the need for nursing care. So far, very few comparative studies have evaluated the efficacy of the three device-aided therapies for specific motor problems in advanced PD. As a result, neurologists currently lack guidance as to which therapy could be most appropriate for a particular PD patient. A group of experts knowledgeable in all three therapies reviewed the currently available literature for each treatment and identified variables of clinical relevance for choosing one of the three options such as type of motor problems, age, and cognitive and psychiatric status. For each scenario, pragmatic and (if available) evidence-based recommendations are provided as to which patients could be candidates for either DBS, DLI, or subcutaneous apomorphine.

Therapeutic stimulation versus ablation

The renaissance of functional stereotactic neurosurgery was pioneered in the mid 1980s by Laitinen's introduction of Leksell's posteroventral pallidotomy for Parkinson´s disease (PD). This ablative procedure experienced a worldwide spread in the 1990s, owing to its excellent effect on dyskinesias and other symptoms of post-l-dopa PD. Modern deep brain stimulation (DBS), pioneered by Benabid and Pollak in 1987 for the treatment of tremor, first became popular when it was applied to the subthalamic nucleus (STN) in the mid 1990s, where it demonstrated a striking effect on all cardinal symptoms of advanced PD, and permitted reduced dosages of medication. DBS, as a nondestructive, adaptable, and reversible procedure that is proving safe in bilateral surgery on basal ganglia, has great appeal to clinicians and patients alike, despite the fact that it is expensive, laborious, and relies on very strict patient selection criteria, especially for STN DBS. Psychiatric surgery has experienced the same phenomenon, with DBS supplanting completely stereotactic ablative procedures. This chapter discusses the pros and cons of ablation versus stimulation and investigates the reasons why DBS has overshadowed proven efficient ablative procedures such as pallidotomy for PD, and capsulotomy and cingulotomy for obsessive-compulsive disorder and depression.

[The indication of DBS in Parkinson' disease (from a neurological standpoint)]

Deep brain stimulation of subthalamic nucleus (STN-DBS) is currently the most common therapeutic surgical treatment for patients with Parkinson's disease (PD) who have failed medical management. The percentage improvement in Unified Parkinson's disease Rating Scale (UPDRS) part II (activities of daily living) and III (motor) scores was more than 50%. Furthermore, levodopa-induced dyskinesias are dramatically improved because STN stimulation permits an approximately 50% reduction in antiparkinsonian treatment. How should we decide an appropriate candidate for DBS? It seems that there is a little difference about indication of DBS between neurosurgeons and neurologists. Since the efficacy of DBS is the improvement in dopaminergic drug-sensitive motor symptoms, we offer surgery to patients only when medical therapy has failed; (1) severe motor fluctuations, (2) severe dyskinesia, (3) tremor uncontrollable by medications, (4) painful dystonia, (5) side-effect for medication (drug-induced psychosis, nausea, vomitting). Taking account of contraindications is important to get successful outcome of the surgery. Dementia, cognitive deficits and psychosis (not drug-induced) are not improved by DBS. When patients are not able to see experienced doctors who manage in programming and dealing with postoperative problems, they are not appropriate candidates. Though benefit to mobility is evident, a risk-benefit assessment should to be made for each patient.

Subthalamic stimulation in Parkinson's disease: restoring the balance of motivated behaviours

Addictions to dopaminergic drugs or to pleasant behaviours are frequent and potentially devastating neuropsychiatric disorders observed in Parkinson's disease. They encompass impulse control disorders, punding and dopamine dysregulation syndrome. A relationship with dopaminergic treatment is strongly suggested. Subthalamic stimulation improves motor complications and allows for drastic reductions in medication. This treatment might, therefore, be considered for patients with behavioural addictions, when attempts to reduce dopaminergic medication have failed. However, conflicting data have reported suppression, alleviation, worsening or new onset of behavioural addictions after subthalamic stimulation. Non-motor fluctuations are also a disabling feature of the disease. We prospectively investigated behaviour in a cohort of 63 patients with Parkinson's disease, before and 1 year after subthalamic stimulation using the Ardouin scale, with systematic evaluation of functioning in overall appetitive or apathetic modes, non-motor fluctuations, dopaminergic dysregulation syndrome, as well as behavioural addictions (including impulse control disorders and punding) and compulsive use of dopaminergic medication. Defined drug management included immediate postoperative discontinuation of dopamine agonists and reduction in levodopa. Motor and cognitive statuses were controlled (Unified Parkinson's Disease Rating Scale, Mattis Dementia Rating Scale, frontal score). After surgery, the OFF medication motor score improved (-45.2%), allowing for a 73% reduction in dopaminergic treatment, while overall cognitive evaluation was unchanged. Preoperative dopamine dysregulation syndrome had disappeared in 4/4, behavioural addictions in 17/17 and compulsive dopaminergic medication use in 9/9 patients. New onset of levodopa abuse occurred in one patient with surgical failure. Non-motor fluctuations were significantly reduced with improvements in off-dysphoria (P ≤ 0.001) and reduction in on-euphoria (P ≤ 0.001). There was an inversion in the number of patients functioning in an overall appetitive mode (29 before versus 2 after surgery, P ≤ 0.0001) to an overall apathetic mode (3 before versus 13 after surgery, P < 0.05). Two patients attempted suicide. Improvement in motor fluctuations is linked to the direct effect of stimulation on the sensory-motor subthalamic territory, while improvement in dyskinesias is mainly explained by an indirect effect related to the decrease in dopaminergic drugs. Our data suggest that non-motor fluctuations could similarly be directly alleviated through stimulation of the non-motor subthalamic territories, and hyperdopaminergic side effects might improve mainly due to the decrease in dopaminergic medication. We show an overall improvement in neuropsychiatric symptomatology and propose that disabling non-motor fluctuations, dopaminergic treatment abuse and drug-induced behavioural addictions in Parkinson's disease may be considered as new indications for subthalamic stimulation.

The Movement Disorder Society Evidence-Based Medicine Review Update: Treatments for the motor symptoms of Parkinson's disease

The objective was to update previous evidence-based medicine reviews of treatments for motor symptoms of Parkinson's disease published between 2002 and 2005. Level I (randomized, controlled trial) reports of pharmacological, surgical, and nonpharmacological interventions for the motor symptoms of Parkinson's disease between January 2004 (2001 for nonpharmacological) and December 2010 were reviewed. Criteria for inclusion, clinical indications, ranking, efficacy conclusions, safety, and implications for clinical practice followed the original program outline and adhered to evidence-based medicine methodology. Sixty-eight new studies qualified for review. Piribedil, pramipexole, pramipexole extended release, ropinirole, rotigotine, cabergoline, and pergolide were all efficacious as symptomatic monotherapy; ropinirole prolonged release was likely efficacious. All were efficacious as a symptomatic adjunct except pramipexole extended release, for which there is insufficient evidence. For prevention/delay of motor fluctuations, pramipexole and cabergoline were efficacious, and for prevention/delay of dyskinesia, pramipexole, ropinirole, ropinirole prolonged release, and cabergoline were all efficacious, whereas pergolide was likely efficacious. Duodenal infusion of levodopa was likely efficacious in the treatment of motor complications, but the practice implication is investigational. Entacapone was nonefficacious as a symptomatic adjunct to levodopa in nonfluctuating patients and nonefficacious in the prevention/delay of motor complications. Rasagiline conclusions were revised to efficacious as a symptomatic adjunct, and as treatment for motor fluctuations. Clozapine was efficacious in dyskinesia, but because of safety issues, the practice implication is possibly useful. Bilateral subthalamic nucleus deep brain stimulation, bilateral globus pallidus stimulation, and unilateral pallidotomy were updated to efficacious for motor complications. Physical therapy was revised to likely efficacious as symptomatic adjunct therapy. This evidence-based medicine review updates the field and highlights gaps for research.

Changes in quality of life, burden and mood among spouses of Parkinson's disease patients receiving neurostimulation

BACKGROUND

Deep brain stimulation improves motor function and quality of life in patients with Parkinson's disease. The impact of these changes on patients' spouses is largely unknown.

METHODS

Twenty-six spouses of patients undergoing surgery were evaluated before and 12 months after surgery, using the 36-Item Short Form Health Survey for quality of life, the Beck Depression Inventory, and the Zarit Burden Inventory.

RESULTS

The spouses' mean mood and quality of life scores changed little, while burden improved in younger spouses. There was no significant change in the spouses' overall status. However, at the individual level the effect of surgery was more frequently negative than positive. Changes in psychological status and quality of life in the spouses did not correlate with changes in the patients' motor status or quality of life.

CONCLUSIONS

Spouses' experience of neurostimulation for Parkinson's disease is variable and complex. The improvement in burden experienced by younger spouses may reflect a greater capacity to cope with new situations.

Moving forward: advances in the treatment of movement disorders with deep brain stimulation

The modern era of stereotactic and functional neurosurgery has ushered in state of the art technologies for the treatment of movement disorders, particularly Parkinson's disease (PD), tremor, and dystonia. After years of experience with various surgical therapies, the eventual shortcomings of both medical and surgical treatments, and several serendipitous discoveries, deep brain stimulation (DBS) has risen to the forefront as a highly effective, safe, and reversible treatment for these conditions. Idiopathic advanced PD can be treated with thalamic, globus pallidus internus (GPi), or subthalamic nucleus (STN) DBS. Thalamic DBS primarily relieves tremor while GPi and STN DBS alleviate a wide range of Parkinsonian symptoms. Thalamic DBS is also used in the treatment of other types of tremor, particularly essential tremor, with excellent results. Both primary and various types of secondary dystonia can be treated very effectively with GPi DBS. The variety of anatomical targets for these movement disorders is indicative of the network-level dysfunction mediating these movement disturbances. Despite an increasing understanding of the clinical benefits of DBS, little is known about how DBS can create such wide sweeping neuromodulatory effects. The key to improving this therapeutic modality and discovering new ways to treat these and other neurologic conditions lies in better understanding the intricacies of DBS. Here we review the history and pertinent clinical data for DBS treatment of PD, tremor, and dystonia. While multiple regions of the brain have been targeted for DBS in the treatment of these movement disorders, this review article focuses on those that are most commonly used in current clinical practice. Our search criteria for PubMed included combinations of the following terms: DBS, neuromodulation, movement disorders, PD, tremor, dystonia, and history. Dates were not restricted.

"I Am Who I Am": On the Perceived Threats to Personal Identity from Deep Brain Stimulation

This article explores the notion of the dislocated self following deep brain stimulation (DBS) and concludes that when personal identity is understood in dynamic, narrative, and relational terms, the claim that DBS is a threat to personal identity is deeply problematic. While DBS may result in profound changes in behaviour, mood and cognition (characteristics closely linked to personality), it is not helpful to characterize DBS as threatening to personal identity insofar as this claim is either false, misdirected or trivially true. The claim is false insofar as it misunderstands the dynamic nature of identity formation. The claim is misdirected at DBS insofar as the real threat to personal identity is the discriminatory attitudes of others towards persons with motor and other disabilities. The claim is trivially true insofar as any dramatic event or experience integrated into one’s identity-constituting narrative could then potentially be described as threatening. From the perspective of relational personal identity, when DBS dramatically disrupts the narrative flow, this disruption is best examined through the lens of agency. For illustrative purposes, the focus is on DBS for the treatment of Parkinson’s disease.

Depression and coping as predictors of change after deep brain stimulation in Parkinson's disease

BACKGROUND

This study examined changes in motor function and quality of life (QoL) after subthalamic nuclei deep brain stimulation (STN-DBS) in patients with Parkinson disease (PD) and the role of psychosocial predictors on individual changes.

METHODS

Forty-one patients with advanced PD (29 men and 12 women; mean age: 62.0 ± 8.0; disease duration: 14.5 ± 5.7) completed self-report questionnaires before surgery and at 6 and 12 months after surgery. Psychosocial measures assessed coping strategies (Ways of Coping Checklist-Revised), symptoms of depression (Beck Depression Inventory version II), anxiety (State-Trait Anxiety Inventory), and QoL (Parkinson Disease Questionnaire 39 Items, Medical Outcomes Study 36-Item Short-Form Health Survey).

RESULTS

After surgery, motor function (Unified Parkinson Disease Rating Scale III and IV), global QoL (Parkinson Disease Questionnaire 39 Items) and Physical Component Summary of the Medical Outcome Study Short Form 36-items Health Survey improved, whereas the Mental Component Summary tended to deteriorate. Depression and anxiety were stable. Improvements in motor function and QoL were associated with younger age, shorter duration of illness, higher baseline distress (depression and anxiety), and changes in problem-focused coping. Improvements in mental QoL were associated with a less frequent use of coping focused on seeking social support.

CONCLUSIONS

STN-DBS is associated with major positive changes in PD affecting motor function and QoL. These changes are related to psychological variables, including emotional distress and coping. A better focus on these individual characteristics is necessary to improve care of patients with PD who undertake STN-DBS.

Assessment of the effects of unilateral electrode dysfunction in patients with Parkinson disease undergoing bilateral subthalamic nucleus deep brain stimulation

BACKGROUND

Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) is the gold standard surgical treatment for medically intractable Parkinson disease, and unilateral electrodes are reported to have beneficial effects. However, assessment of patients after electrode failure needs to be established.

OBJECTIVE

To assess the effects of the remaining unilateral electrode in Parkinson disease after bilateral STN-DBS.

METHODS

Between May 2000 and March 2009, 8 patients had unilateral STN-DBS after bilateral STN-DBS. We assessed clinical outcome by comparing the Unified Parkinson Disease Rating Scale (UPDRS) motor score, activities of daily living, levodopa-equivalent daily dosages, and quality of life according to the Short-Form 36 Health Survey between patients with unilateral and bilateral electrodes.

RESULTS

Although ipsilateral and axial UPDRS motor scores were compromised, UPDRS motor scores contralateral to the side of the implant remained unaltered after removal of 1 electrode. Although physical aspects of quality of life declined significantly with a unilateral electrode, pain and social functioning were not significantly affected. No significant changes in activities of daily living, Hoehn and Yahr stage, or levodopa-equivalent daily dosage were observed after removal of 1 electrode.

CONCLUSION

The UPDRS motor score with unilateral STN-DBS was compromised relative to bilateral STN-DBS for ipsilateral motor and axial symptoms. When 1 electrode is compromised, revision of that electrode will eventually be required, but not immediately in all patients. If a patient tolerates loss of 1 electrode according to motor score while maintaining activities of daily living and quality of life, it is possible to wait and observe the situation instead of immediately revising the electrode.

Changes in cognitive-emotional and physiological symptoms of depression following STN-DBS for the treatment of Parkinson's disease

BACKGROUND AND PURPOSE

Subthalamic nucleus deep brain stimulation (STN-DBS) has been shown to have beneficial effects on the motor features of Parkinson's disease (PD), but its impact on non-motor symptoms, most notably mood, has not been fully explored.

METHODS

In the first study to independently compare the emotional-cognitive and somatic/physiological symptoms of depression, we examined mood differences in 17 bilateral STN-DBS and 22 matched non-surgical PD patients at baseline and 6 months.

RESULTS

The STN-DBS group reported higher levels of depression at baseline with significant endorsement of physical symptomatology. Postoperatively, no significant between-group differences in physical symptoms of depression were found. In contrast, a significant group by time interaction for cognitive-emotional symptoms of depression was found, with the STN-DBS group reporting an increase in psychological symptoms of distress. The STN-DBS group also reported an increase in anxiety following surgery. The suicide rate of 5% found in our study is consistent with other postoperative studies in PD. The impact of changes in levodopa and psychotropic medication are also explored.

CONCLUSIONS

Preliminary results suggest that the motor improvement often observed in patients with PD following bilateral STN-DBS may be partially offset by an increase in affective-cognitive symptoms of depression.

Patients' perceptions of life shift after deep brain stimulation for primary dystonia--A qualitative study

Studies of deep brain stimulation for dystonia have shown significant motor improvement. However, patients' perceptions of surgery and its effects have been less studied. We aimed to explore perceptions of changes in life in patients with primary dystonia after deep brain stimulation. Thirteen patients underwent thematic interviews 8-60 months after pallidal deep brain stimulation. Interviews were transcribed verbatim and analyzed with grounded theory. Patients described a profound impact of dystonia on daily life. After surgery, physical changes with a more upright posture and fewer spasms translated into an easier, more satisfying life with greater confidence. Notwithstanding this positive outcome, the transition from a limited life before surgery to opportunities for a better life exhibited obstacles: The "new life" after deep brain stimulation was stressful, including concern about being dependent on the stimulator as well as having to deal with interfering side effects from deep brain stimulation. The whole coping process meant that patients had to quickly shift focus from struggling to adapt to a slowly progressive disorder to adjustment to a life with possibilities, but also with new challenges. In this demanding transition process, patients wished to be offered better professional guidance and support. Even though deep brain stimulation provides people with primary dystonia with a potential for better mobility and more confidence, patients experienced new challenges and expressed the need for support and counseling after surgery. Grounded theory is a useful method to highlight patients' own experience and contributes to a deeper understanding of the impact of deep brain stimulation on patients with dystonia.

Me, Myself and My Brain Implant: Deep Brain Stimulation Raises Questions of Personal Authenticity and Alienation

In this article, I explore select case studies of Parkinson patients treated with deep brain stimulation (DBS) in light of the notions of alienation and authenticity. While the literature on DBS has so far neglected the issues of authenticity and alienation, I argue that interpreting these cases in terms of these concepts raises new issues for not only the philosophical discussion of neuro-ethics of DBS, but also for the psychological and medical approach to patients under DBS. In particular, I suggest that the experience of alienation and authenticity varies from patient to patient with DBS. For some, alienation can be brought about by neurointerventions because patients no longer feel like themselves. But, on the other hand, it seems alienation can also be cured by DBS as other patients experience their state of mind as authentic under treatment and retrospectively regard their former lives without stimulation as alienated. I argue that we must do further research on the relevance of authenticity and alienation to patients treated with DBS in order to gain a deeper philosophical understanding, and to develop the best evaluative criterion for the behavior of DBS patients.

Ethical issues in deep brain stimulation

Deep brain stimulation (DBS) is currently used to treat neurological disorders like Parkinson's disease, essential tremor, and dystonia, and is explored as an experimental treatment for psychiatric disorders like major depression and obsessive compulsive disorder. This mini review discusses ethical issues in DBS treatment and research, as they have been discussed in the medical and ethical literature. With regard to DBS treatment, the most important issues are balancing risks and benefits and ensuring respect for the autonomous wish of the patient. This implies special attention to patient selection, psycho-social impact of treatment, effects on personal identity, and treatment of children. Moreover, it implies a careful informed consent process in which unrealistic expectations of patients and their families are addressed and in which special attention is given to competence. In the context of research, the fundamental ethical challenge is to promote high-quality scientific research in the interest of future patients, while at the same time safeguarding the rights and interests of vulnerable research subjects. Several guidelines have been proposed to ensure this. One of the preconditions to further development of responsible and transparent research practices is the establishment of a comprehensive registry.

A review of social and relational aspects of deep brain stimulation in Parkinson's disease informed by healthcare provider experiences

Background. Although the clinical effectiveness of deep brain stimulation (DBS) in Parkinson's disease is established, there has been less examination of its social aspects. Methods and Results. Building on qualitative comments provided by healthcare providers, we present four different social and relational issues (need for social support, changes in relationships (with self and partner) and challenges with regards to occupation and the social system). We review the literature from multiple disciplines on each issue. We comment on their ethical implications and conclude by establishing the future prospects for research with the possible expansion of DBS for psychiatric indications. Conclusions. Our review demonstrates that there are varied social issues involved in DBS. These issues may have significant impacts on the perceived outcome of DBS by patients. Moreover, the fact that the social impact of DBS is still not well understood in emerging psychiatric indications presents an important area for future examination.

Parkinson’s disease DBS: what, when, who and why? The time has come to tailor DBS targets

Deep brain stimulation (DBS) has recently been proven to be an effective therapy for medication refractory symptoms of Parkinson's disease. As the evidence base continues to evolve, many important issues have surfaced, including: what operation should be performed (brain target[s],unilateral vs bilateral, simultaneous vs staged); when to operate (how early is too early to intervene?), who should be operated on (disease duration, age, symptom profiles and the use of the interdisciplinary screening team); and finally, why to operate (the rationale of surgery vs medication/apomorphine pumps/duodopa pumps/stem cell trials/gene therapy trials). We will address each of these critical issues, as well make the argument that a tailored approach to DBS and DBS targeting will best serve each potential candidate. We will review the multiple peer reviewed studies and we will emphasize the recently available data from randomized DBS studies.We will argue that moving away from a single DBS target (e.g., subthalamic nucleus DBS) and a single approach to DBS methodology (e.g., bilateral simultaneous operations) is a reasonable next step for the Parkinson's disease community. Following careful interdisciplinary DBS screening, a physician-patient discussion has the potential to establish a patient-centered and symptom-specific outcome for each potential DBS candidate. The interdisciplinary DBS team can function together to formulate and to consider an optimal and tailored approach. A tailored approach will allow for the consideration of the complex and numerous variables that may contribute to a positive or negative overall DBS outcome. We will review and provide expert commentary on a potential interdisciplinary approach to selecting unilateral or alternatively bilateral subthalamic nucleus or globus pallidus internus DBS. Our approach is aimed to maximize benefit(s) and minimize risk(s) in order to best tailor therapy for an individual patient.

Deep Brain Stimulation and the Search for Identity

Ethical evaluation of deep brain stimulation as a treatment for Parkinson’s disease is complicated by results that can be described as involving changes in the patient’s identity. The risk of becoming another person following surgery is alarming for patients, caregivers and clinicians alike. It is one of the most urgent conceptual and ethical problems facing deep brain stimulation in Parkinson’s disease at this time. In our paper we take issue with this problem on two accounts. First, we elucidate what is meant by “becoming another person” from a conceptual point of view. After critically discussing two broad approaches we concentrate on the notion of “individual identity” which centers on the idea of “core attitudes”. Subsequently we discuss several approaches to determine what distinguishes core attitudes from those that are more peripheral. We argue for a “foundational-function model” highlighting the importance of specific dependency relations between these attitudes. Our second aim is to comment on the possibility to empirically measure changes in individual identity and argue that many of the instruments now commonly used in selecting and monitoring DBS-patients are inappropriate for this purpose. Future research in this area is advised combining a conceptual and an empirical approach as a basis of sound ethical appraisal.

Deep brain stimulation for hyperkinetics disorders: dystonia, tardive dyskinesia, and tics

PURPOSE OF REVIEW

This review focuses on new insights in deep brain stimulation (DBS) for patients with hyperkinetic movement disorders: dystonia, tardive dyskinesia and Gille de la Tourette's syndrome, during the last 18 months.

RECENT FINDINGS

The recent literature confirms the efficacy of high-frequency stimulation of the globus pallidus internus (GPi) for primary dystonia, generalized or not, with a stable effect over time. The benefit of DBS in other forms of localized dystonia remains to be demonstrated in larger studies. Some clinical and radiological predictive factors have been determined with a predominant influence of the disease duration. Tardive dystonia and myoclonus-dystonia are also improved by GPi stimulation. Encouraging results obtained in cerebral palsy may pave the way for the application of DBS in other secondary dystonia. In Gilles de la Tourette's syndrome, both stimulation of the centre-median/parafascicular nucleus of the thalamus and GPi stimulation (ventromedial) have demonstrated efficacy with stable long-term effect. Thalamic stimulation failed to improve obsessions and compulsions in some patients. Stimulation of the nucleus accumbens has been tested in few cases with contradictory efficacy. In both diseases, complications are rare with no major side effects.

SUMMARY

The few controlled studies showed that bilateral GPi stimulation is a well tolerated and a long-term effective treatment for hyperkinetic disorders. However, recent published data of DBS applied in different targets or patients (especially secondary dystonia) are mainly uncontrolled case reports, precluding the clear determination of the efficacy of this procedure and the choice of the 'good' target for the 'good' patient.

Cognitive outcome and reliable change indices two years following bilateral subthalamic nucleus deep brain stimulation

Subthalamic nucleus deep brain stimulation (STN-DBS) is currently the treatment of choice for medication-resistant levodopa-related motor complications in patients with Parkinson's disease (PD). While STN-DBS often results in meaningful motor improvements, consensus regarding long-term neuropsychological outcome continues to be debated. We assessed the cognitive outcomes of 19 STN-DBS patients compared to a group of 18 medically-managed PD patients on a comprehensive neuropsychological battery at baseline and two years post-surgery. Patients did not demonstrate changes in global cognitive functioning on screening measures. However, neuropsychological results revealed impairments in nonverbal recall, oral information processing speed, and lexical and semantic fluency in STN-DBS patients compared to PD controls 2 years post-surgery in these preliminary analyses. Additionally, reliable change indices revealed that approximately 50% of STN-DBS patients demonstrated significant declines in nonverbal memory and oral information processing speed compared to 25-30% of PD controls, and 26% of STN-DBS patients declined on lexical fluency compared to 11% of PD patients. Approximately 30% of both groups declined on semantic fluency. The number of STN-DBS patients who converted to dementia 2 years following surgery was not significantly different from the PD participants (32% versus 16%, respectively). Our results suggest that neuropsychological evaluations may identify possible mild cognitive changes following surgery.

A meta-regression of the long-term effects of deep brain stimulation on balance and gait in PD

OBJECTIVE

Deep brain stimulation (DBS) alleviates the cardinal Parkinson disease (PD) symptoms of tremor, rigidity, and bradykinesia. However, its effects on postural instability and gait disability (PIGD) are uncertain. Contradictory findings may be due to differences the in stimulation site and the length of time since DBS surgery. This prompted us to conduct the first meta-regression of long-term studies of bilateral DBS in the subthalamic nucleus (STN) and globus pallidus interna (GPi).

RESULTS

Eleven articles reported a breakdown of the Unified Parkinson's Disease Rating Scale score before and beyond 3 years postsurgery (mean 4.5 years). Random effects meta-regression revealed that DBS initially improved PIGD compared to the OFF medicated state before surgery, but performance declined over time and extrapolation showed subjects would reach presurgery levels 9 years postsurgery. ON medication, DBS improved PIGD over and above the effect of medication before surgery. Nevertheless, for the STN group, PIGD progressively declined and was worse than presurgery function within 2 years. In contrast, GPi patients showed no significant long-term decline in PIGD in the medicated state. Improvements in cardinal signs with DBS at both sites were maintained across 5 years in the OFF and ON medication states.

CONCLUSIONS

DBS alone does not offer the same improvement to PIGD as it does to the cardinal symptoms, suggesting axial and distal control are differentially affected by DBS. GPi DBS in combination with levodopa seemed to preserve PIGD better than did STN DBS, although more studies of GPi DBS and randomized controls are needed.