Psychosocial adjustment after deep brain stimulation in Parkinson's disease

Parkinson's Disease: Coping Strategies, Cognitive Restructuring and Deep Brain Stimulation

OBJECTIVE

Less is known concerning the evolution of coping strategies before and after deep brain stimulation (DBS) in Parkinson's disease (PD) patients.

METHODS

In a randomized controlled trial, coping was measured with the neurological version of the CHIP (Coping with Health Injuries and Problem) and the BriefCOPE in PD patients before ( T1: DBS - 2 months) and after (T2: + 3 months, T3: + 6 months) DBS. Patients (N = 50, age 59 ± 5.7 years, disease duration 9.54 ± 3.7 years) were randomised in 3 groups: CRTG (preoperative psychological preparation with cognitive restructuring), PIG (preoperative non structured interviews), and CG (no psychological preparation).

RESULTS

Coping strategies are modulated by the time of evaluation. Some strategies are significantly more used preoperatively than postoperatively, as strategies about the research for information (CHIP: F = 16.14; P = .000; η2 = .095; BriefCOPE F = 5.71; P = .005; η2 = .066), emotional regulation (F = 3.29; P = .042; η2 = .029), and well-being searching (F = 4.59; P = .013; η2 = .043). Some other strategies appear more used post than preoperatively, as palliative coping (F = 5.57; P = .005; η2 = .064), humour (F = 3.35; P = .041; η2 = .0.35), and use of substance (F = 4.43; P = .015; η2 = .070). No other specific time, group or time per group interaction effect was found.

CONCLUSION

Coping strategies are crucial for PD patients to adapt to the evolution of their parkinsonian state. Their consideration should be more systematic in the neurosurgical process, particularly when neurological symptoms would remain after DBS. More insights are needed concerning the evolution of coping strategies through DBS and the impact of a preoperative psychotherapy over them in preoperative PD patients.

Illness perceptions in pre-operative Parkinson's disease patients

Parkinson's disease (PD) is a neurodegenerative disease, that combines motor and non-motor disorders, and alters patients' autonomy. Even if subthalamic nucleus deep brain stimulation (STN-DBS) induces undisputable motor improvement, a post-operative social maladjustment was described by some patients. Our aim was to describe pre-operative illness perceptions in parkinsonian patients, and to determine the possible impact of cognitive restructuration over them. We analyzed 27 parkinsonian patient's candidates to DBS. The mean age was 59 ± 5.94 years, and mean disease duration was 9.89 ± 4.15 years. The patients had two pre-operative psychological interviews (DBS-45 days, DBS-25 days) and completed the Illness Perception Questionnaire-Revised (IPQ-R) before the first interview and at DBS-1 day. The CRTG group (n = 13) had cognitive restructuration during second interview, on dysfunctional cognitions about their perception of post-DBS life which emerged from the first interview. The PIG group (n = 14) benefited of two non-structured interviews. No significant differences were found between the visits (DBS-45 days, DBS-1 day) for IPQ-R dimensions, except for the perception of "personal control" over PD which appears significantly higher for CRTG than PIG group (p = .039) at DBS-1 day, whereas the scores were quite similar at DBS-45 days. Illness perceptions seem to be stable over time and mostly influenced by disease experience of PD. However, the perception of personal control over PD seemed to be modulated through cognitive restructuration, giving patients' control back over disease. Before DBS, illness perceptions investigation and restructuration constitute an interesting point to work on, to enhance perceived benefits of neurosurgery.Trial registration: Clinical Research Program, N°IDRCB 2008-A00655-50, approved by the local ethics committee (CPP EST III, N° CPP: 08.07.03, first version date: 04/01/2008), registered on the ClinicalTrials.gov website (NCT02893449).

Personality Related to Quality-of-Life Improvement After Deep Brain Stimulation in Parkinson's Disease (PSYCHO-STIM II)

BACKGROUND

Deep brain stimulation of the sub-thalamic nucleus (DBS-STN) reduces symptoms in Parkinson's disease (PD) patients with motor fluctuations. However, some patients may not feel ameliorated afterwards, despite an objective motor improvement. It is thus important to find new predictors of patients' quality of life (QoL) amelioration after DBS-STN. We hypothesized that personality dimensions might affect QoL after DBS-STN.

OBJECTIVE

To evaluate associations between personality dimensions and QoL improvement one year after DBS-STN.

METHODS

DBS-STN-PD patients (n = 303) having answered the "Temperament and Character Inventory" (TCI) before surgery and the PDQ-39 before and one year after surgery were included, from the cohort study PREDI-STIM. Linear regression models were used to evaluate associations between TCI dimensions and change in PDQ-39 scores after DBS-STN.

RESULTS

Novelty Seeking and Cooperativeness scores before surgery were positively associated with PDQ-39 scores improvement after DBS-STN (FDR-adjusted p < 0.01). Moreover, paradoxically unimproved patients with deterioration of their PDQ-39 scores after DBS-STN despite improvement of their MDS-UPDRS-IV scores had lower Cooperativeness scores, while paradoxically improved patients with amelioration of their PDQ-39 scores despite deterioration of their MDS-UPDRS-IV scores had higher Reward Dependence scores.

CONCLUSION

Some presurgical personality dimensions were significantly associated with QoL amelioration and discrepancy between motor state and QoL changes after DBS-STN in PD. Educational programs before DBS-STN should take in account patient personality dimensions to better deal with their expectations.

Evaluation of the Impact of Integrated Care and Self-Management After Deep Brain Stimulation in Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) is a progressive neurodegenerative disorder with a myriad of motor and non-motor symptoms. Although deep brain stimulation (DBS) has a dramatic impact in the lives of people with PD, care delivery remains complex. There is a lack of evidence on the implementation and role of integrated care and self-management support in people with PD with chronic DBS.

OBJECTIVE

To evaluate care needs, implementation and impact of a pragmatic network for PD care, the Integrated Parkinson Care Network (IPCN).

METHODS

This is a subgroup analyses of a 6-month, pre-post design, single-centre, phase 2 study to assess a patient-centred care model based on integrated care, self-management support (IPCN) in PD, focusing on those participants with chronic DBS.

RESULTS

We included 22 people with PD and chronic DBS (median time since DBS - 30 months). The mean age was 63.9 (7.6) years and mean disease duration was 15.2 (6.9) years. The top three care priorities were speech (54.5%), mobility (40.9%) and mood (31.8%). After the IPCN program, there was a positive change in the perception of support for chronic care (Patient Assessment of Chronic Illness Case: 0.85; 95% CI: 1.2 to -0.4) and self-management (5As: 0.77; 95% CI: 0.39 -1.15), along with quality of life (PDQ8 : 7.1, 95% CI:1.8 -12.4).

CONCLUSION

The IPCN is a care delivery model that addresses specific care needs of people with PD and chronic DBS. The current study showed its feasibility and warrants further evaluation.

How Parkinson's patients in the USA perceive deep brain stimulation in the 21st century: Results of a nationwide survey

Research on attitudes regarding the use and timing of deep brain stimulation (DBS) has been mostly qualitative to this date. In this study, we aim to examine attitudes and perceptions about the use and timing of DBS in patients with Parkinson's disease (PD) who have not had DBS. We designed an online survey comprising Likert-type, multiple choice, and rank-order questions and distributed it to PD patients. We recruited participants via flyers, the Michael J. Fox Foundation Trial Finder, and the Parkinson Alliance website. We analyzed considerations for choosing or rejecting DBS and when participants would consider such a decision to be premature. Data were analyzed using descriptive and inferential statistics, including a multinomial logistic regression model. Among the 285 participants who reported not having undergone DBS, the most frequent concerns were related to the efficacy of DBS and not having exhausted medication alternatives. DBS was viewed as less convenient, effective, and safe when PD symptoms were still manageable by medication. Our regression model suggests that having fewer concerns over technical problems was a positive predictor of preferring early DBS, while concerns over DBS interfering with friendships and relationships was a negative predictor. Our results suggest that patients with PD who have not undergone DBS have a wide variety of attitudes regarding DBS and its timing. Given the increasing number of therapeutic options for PD, future work should compare perceptions and preferences regarding different PD treatment modalities to provide the best counseling for patients regarding their therapeutic options.

Parkinson's Disease and Bilateral Subthalamic Nuclei Deep Brain Stimulation: Beneficial Effects of Preoperative Cognitive Restructuration Therapy on Postoperative Social Adjustment

BACKGROUND

Bilateral subthalamic nucleus deep brain stimulation improves motor symptoms and treatment-related complications in patients with Parkinson's disease. However, some patients have trouble adjusting socially after successful neurosurgery, in part because of "unrealistic" expectations and psychiatric disorders. Preoperative psychological interventions focusing on these aspects could be beneficial for such patients.

METHODS

We compared the outcomes of 2 psychosocial approaches-1 based on cognitive restructuration and 1 consisting of 2 interviews-with those of a control group without preoperative preparation. All patients underwent a psychometric evaluation 2 months before surgery (M-2) and again at 3 (M+3) and 6 months (M+6) after surgery. The psychometric evaluation focused on social adjustment using the social adjustment scale-self-report. The psychiatric profile of the patients was also assessed.

RESULTS

Of 73 patients initially enrolled, 62 performed the initial inclusion visit (M-2) and the 2 postoperative visits (M+3, M+6). For these 62 patients (52% male), the overall mean age was 59 ± 6.13 years, and the mean disease duration was 9.44 ± 3.62 years. No specific differences were observed for social adjustment between the groups or visits (M-2, M+3, M+6); however, an interaction was found in the cognitive restructuration group at M+6 for the family dimension of the social adjustment scale-self-report.

CONCLUSION

Our results suggest that even if no overall increase in the social adjustment score was observed, patients with Parkinson's disease eligible for neurosurgery should undergo preoperative psychosocial therapy to define their expectations and help them in their psychological restructuration. This type of therapy, complementary to psychoeducation, could represent an opportunity to prevent postoperative deception and social maladjustment.

Identifying the trajectory of social milestones 15-20 years after epilepsy surgery: Realistic timelines for postsurgical expectations

OBJECTIVE

Patients often undertake epilepsy surgery with the expectation that it will lead to improvements in their social situation. Short- to medium-term research consistently points toward improvements in social outcomes; however, no study has mapped out postsurgical social timelines, particularly for longer-term (>15 years) outcomes.

METHODS

We recruited 39 patients who had undergone anterior temporal lobectomy (ATL) for drug-resistant temporal lobe epilepsy (TLE) between 1994 and 2002. The cohort (24 females) had a median age of 49 years (range 38-67), age of habitual seizure onset was 9.5 years (range 0.5-29 years), and age at surgery was 31 years (range 20-53). Patients were followed up for a median of 18.4 years postsurgery (IQR = 4.4). Using data obtained from semistructured interviews, we conducted a comprehensive qualitative analysis of patients' self-reported postsurgical social trajectories. Self-report questionnaires were used to assess mood and health-related quality of life (HRQOL) at the time of interview.

RESULTS

There was a common sequence of social milestone achievement, spanning 20 years postsurgery. Typically, patients first (re)gained their license, then attempted educational and vocational gains, followed by establishing long-term relationships and finally a family unit. Rare, intermittent seizures postsurgery did not appear to have detrimental effects on social trajectories. Those who experienced a reduction in seizures showed increased likelihood of attaining social milestones compared to those with ongoing seizures.

SIGNIFICANCE

Achieving social milestones after epilepsy surgery may take considerably longer than patients are expecting prior to surgery. The pattern of social milestone outcome resembled a process of psychosocial development. These findings have important implications for presurgical counseling and postsurgical rehabilitation.

A Neuroethics Framework for the Australian Brain Initiative

Neuroethics is central to the Australian Brain Initiative's aim to sustain a thriving and responsible neurotechnology industry. Diverse and inclusive community and stakeholder engagement and a trans-disciplinary approach to neuroethics will be key to the success of the Australian Brain Initiative.

Deep brain stimulation for people with Alzheimer's disease: Anticipating potential effects on the tripartite self

Memory dysfunction and cognitive impairments due to Alzheimer’s disease can affect the selfhood and identity of afflicted individuals, causing distress to both people with Alzheimer’s disease and their caregivers. Recently, a number of case studies and clinical trials have been conducted to determine the potential of deep brain stimulation as a therapeutic modality for people with Alzheimer’s disease. Some of these studies have shown that deep brain stimulation could induce flashbacks and stabilize or even improve memory. However, deep brain stimulation itself has also been attributed as a potential threat to identity and selfhood, especially when procedure-related adverse events arise. We anticipate potential effects of deep brain stimulation for people with Alzheimer’s disease on selfhood, reconciling information from medical reports, psychological, and sociological investigations on the impacts of deep brain stimulation or Alzheimer’s disease on selfhood. A tripartite model of the self that extends the scope of Rom Harré’s and Steve Sabat’s social constructionist framework was used. In this model, potential effects of deep brain stimulation for Alzheimer’s disease on Self 1 or singularity through use of first-person indexicals, and gestures of self-reference, attribution, and recognition; Self 2 or past and present attributes, knowledge of these characteristics, and continuity of narrative identity; and Self 3 or the relational and social self are explored. The ethical implications of potential effects of deep brain stimulation for Alzheimer’s disease on the tripartite self are then highlighted, focusing on adapting informed consent procedures and care provided throughout the trial to account for both positive and negative plausible effects on Self 1, Self 2, and Self 3.

Role of clinical neuropsychology in deep brain stimulation: Review of the literature and considerations for clinicians

Deep Brain Stimulation (DBS) is an effective surgical therapy for several neurological movement disorders. The clinical neuropsychologist has a well-established role in the neuropsychological evaluation and selection of surgical candidates. In this article, we argue that the clinical neuropsychologist's role is much broader, when considered in relation to applied psychologists' core competencies. We consider the role of the clinical neuropsychologist in DBS in relation to: assessment, formulation, evaluation and research, intervention or implementation, and communication. For each competence the relevant evidence-base was reviewed. Clinical neuropsychology has a vital role in presurgical assessment of cognitive functioning and psychological, and emotional and behavioral difficulties. Formulation is central to the selection of surgical candidates and crucial to intervention planning. Clinical neuropsychology has a well-established role in postsurgical assessment of cognitive functioning and psychological, emotional, and behavioral outcomes, which is fundamental to evaluation on an individual and service level. The unique contribution clinical neuropsychology makes to pre- and postsurgical interventions is also highlighted. Finally, we discuss how clinical neuropsychology can promote clear and effective communication with patients and between professionals.

Deep Brain Stimulation: In Search of Reliable Instruments for Assessing Complex Personality-Related Changes

During the last 25 years, more than 100,000 patients have been treated with Deep Brain Stimulation (DBS). While human clinical and animal preclinical research has shed light on the complex brain-signaling disturbances that underpin e.g., Parkinson's disease (PD), less information is available when it comes to complex psychosocial changes following DBS interventions. In this contribution, we propose to more thoroughly investigate complex personality-related changes following deep brain stimulation through refined and reliable instruments in order to help patients and their relatives in the post-surgery phase. By pursuing this goal, we first outline the clinical importance DBS has attained followed by discussing problematic and undesired non-motor problems that accompany some DBS interventions. After providing a brief definition of complex changes, we move on by outlining the measurement problem complex changes relating to non-motor symptoms currently are associated with. The latter circumstance substantiates the need for refined instruments that are able to validly assess personality-related changes. After providing a brief paragraph with regard to conceptions of personality, we argue that the latter is significantly influenced by certain competencies which themselves currently play only a tangential role in the clinical DBS-discourse. Increasing awareness of the latter circumstance is crucial in the context of DBS because it could illuminate a link between competencies and the emergence of personality-related changes, such as new-onset impulse control disorders that have relevance for patients and their relatives. Finally, we elaborate on the field of application of instruments that are able to measure personality-related changes.

Analyzing 7000 texts on deep brain stimulation: what do they tell us?

The enormous increase in numbers of scientific publications in the last decades requires quantitative methods for obtaining a better understanding of topics and developments in various fields. In this exploratory study, we investigate the emergence, trends, and connections of topics within the whole text corpus of the deep brain stimulation (DBS) literature based on more than 7000 papers (title and abstracts) published between 1991 to 2014 using a network approach. Taking the co-occurrence of basic terms that represent important topics within DBS as starting point, we outline the statistics of interconnections between DBS indications, anatomical targets, positive, and negative effects, as well as methodological, technological, and economic issues. This quantitative approach confirms known trends within the literature (e.g., regarding the emergence of psychiatric indications). The data also reflect an increased discussion about complex issues such as personality connected tightly to the ethical context, as well as an apparent focus on depression as important DBS indication, where the co-occurrence of terms related to negative effects is low both for the indication as well as the related anatomical targets. We also discuss consequences of the analysis from a bioethical perspective, i.e., how such a quantitative analysis could uncover hidden subject matters that have ethical relevance. For example, we find that hardware-related issues in DBS are far more robustly connected to an ethical context compared to impulsivity, concrete side-effects or death/suicide. Our contribution also outlines the methodology of quantitative text analysis that combines statistical approaches with expert knowledge. It thus serves as an example how innovative quantitative tools can be made useful for gaining a better understanding in the field of DBS.

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.

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.

Management of motor and non-motor symptoms in Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder that affects approximately 1 % of people over the age of 60 years. Accurate diagnosis and individualized assessment of the risks and benefits of available antiparkinsonian medications as well as specific clinical features and the phase of disease should guide treatment for patients with PD. Levodopa still remains the gold standard for the treatment of motor symptoms of PD but dopamine agonists (DAs), catechol-O-methyltransferase (COMT) inhibitors and monoamine oxidase B (MAO-B) inhibitors have also been developed to provide more continuous oral delivery of dopaminergic stimulation in order to improve motor outcomes and decrease the risk of levodopa-induced motor complications. Deep-brain stimulation as well as other invasive therapies can be used for the treatment of drug-refractory levodopa-induced motor complications. Despite all of the therapeutic advances achieved within the last 20 years, PD continues to be a progressive disorder leading to severe disability caused by motor and non-motor symptoms. To date, neuroprotective interventions able to modify PD progression are not available. This review focuses on medical and invasive treatment strategies for early and advanced stages of PD as well as on the treatment of PD non-motor symptoms such as mood and behavioural disorders, cognitive and autonomic dysfunction, and sleep disorders, which can antedate PD motor symptoms for years.

Finding gaps and building bridges in movement disorders

Movement disorders are one of the most rapidly growing fields of neurology from both the clinical and neurobiological perspectives. Despite many recent advances in genetic, pathogenetic, clinical and therapeutic fields, several shortcomings remain in the diagnostic and therapeutic realms, with a plethora of challenges threatening further advances. Aimed at recognizing and bridging these knowledge gaps, the 2nd International Conference on Knowledge Gaps in Parkinson's Disease and Other Movement Disorders was held last February in Santa Margherita Ligure, Italy, with the support of the Movement Disorder Society and the Italian Association for Parkinson's Disease and Extrapyramidal Disorders. The 3-day symposium, which was attended by approximately 300 clinicians and researchers from around the world, gathered around 27 leading young and senior clinical scientists, each of whom addressed the field's main knowledge gaps and brainstormed on how to bridge or minimize their impact. This meeting report summarizes the topics that gathered the most attention from the speakers and the audience.

Deep brain stimulation and ethics: perspectives from a multisite qualitative study of Canadian neurosurgical centers

OBJECTIVE

Deep brain stimulation (DBS) is an approved neurosurgical intervention for motor disorders such as Parkinson disease. The emergence of psychiatric uses for DBS combined with the fact that it is an invasive and expensive procedure creates important ethical and social challenges in the delivery of care that need further examination. We endeavored to examine health care provider perspectives on ethical and social challenges encountered in DBS.

METHODS

Health care providers working in Canadian DBS surgery programs participated in a semistructured interview to identify and characterize ethical and social challenges of DBS. A content analysis of the interviews was conducted.

RESULTS

Several key ethical issues, such as patient screening and resource allocation, were identified by members of neurosurgical teams. Providers described challenges in selecting patients for DBS on the basis of unclear evidence-based guidance regarding behavioral issues or cognitive criteria. Varied contexts of resource allocation, including some very challenging schemas, were also reported. In addition, the management of patients in the community was highlighted as a source of ethical and clinical complexity, given the need for coordinated long-term care.

CONCLUSIONS

This study provides insights into the complexity of ethical challenges that providers face in the use of DBS across different neurosurgical centers. We propose actions for health care providers for the long-term care and postoperative monitoring of patients with DBS. More data on patient perspectives in DBS would complement the understanding of key challenges, as well as contribute to best practices, for patient selection, management, and resource allocation.

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.

Reversing cognitive-motor impairments in Parkinson's disease patients using a computational modelling approach to deep brain stimulation programming

Deep brain stimulation in the subthalamic nucleus is an effective and safe surgical procedure that has been shown to reduce the motor dysfunction of patients with advanced Parkinson's disease. Bilateral subthalamic nucleus deep brain stimulation, however, has been associated with declines in cognitive and cognitive-motor functioning. It has been hypothesized that spread of current to nonmotor areas of the subthalamic nucleus may be responsible for declines in cognitive and cognitive-motor functioning. The aim of this study was to assess the cognitive-motor performance in advanced Parkinson's disease patients with subthalamic nucleus deep brain stimulation parameters determined clinically (Clinical) to settings derived from a patient-specific computational model (Model). Data were collected from 10 patients with advanced Parkinson's disease bilaterally implanted with subthalamic nucleus deep brain stimulation systems. These patients were assessed off medication and under three deep brain stimulation conditions: Off, Clinical or Model based stimulation. Clinical stimulation parameters had been determined based on clinical evaluations and were stable for at least 6 months prior to study participation. Model-based parameters were selected to minimize the spread of current to nonmotor portions of the subthalamic nucleus using Cicerone Deep Brain Stimulation software. For each stimulation condition, participants performed a working memory (n-back task) and motor task (force tracking) under single- and dual-task settings. During the dual-task, participants performed the n-back and force-tracking tasks simultaneously. Clinical and Model parameters were equally effective in improving the Unified Parkinson's disease Rating Scale III scores relative to Off deep brain stimulation scores. Single-task working memory declines, in the 2-back condition, were significantly less under Model compared with Clinical deep brain stimulation settings. Under dual-task conditions, force tracking was significantly better with Model compared with Clinical deep brain stimulation. In addition to better overall cognitive-motor performance associated with Model parameters, the amount of power consumed was on average less than half that used with the Clinical settings. These results indicate that the cognitive and cognitive-motor declines associated with bilateral subthalamic nucleus deep brain stimulation may be reversed, without compromising motor benefits, by using model-based stimulation parameters that minimize current spread into nonmotor regions of the subthalamic nucleus.