Preoperative Parkinson's Disease Research Articles

Development and validation of the DBS-PS (Deep Brain Stimulation-Perception Scale): Assessing parkinsonian patients' expectations to prevent post-operative disappointment?

BackgroundRecent literature suggests that taking into consideration and evaluating preoperative expectations of Parkinson's disease (PD) patients candidates to deep brain stimulation (DBS), can contribute to treatment effectiveness. However, few validated instruments investigating preoperative expectations are available. We present the development and validation of the DBS-PS (Deep Brain Stimulation – Perception Scale). MethodsThe DBS-PS is an 11 questions self-administered scale, with answers rated on a 10-point Likert scale (1 completely false, 10 completely true). Items were generated on the basis of patient's interviews analyzed by an expert group and reached consensus. The scale is divided into three domains: expectations for PD, expectations for social-life and leisure, expectations for intimate life. Exploratory factor analysis (EFA) completed by item response theory (IRT) analysis was conducted to validate the theoretical structure of the DBS-PS. Results64 PD patients aged 59.18 (SD = 5.74) years with PD diagnosed since 9.36 (SD = 4.09) years completed the DBS-PS preoperatively. EFA confirmed a 3 factors scale structure (eigenvalue >1) explaining 69% of variance (factor 1: 43%; factor 2: 17%; factor 3: 9%). Reliability (Cronbach's α: 0.714 for factor 1, 0.781 for factor 2, 0.889 for factor 3) and discriminant validity (Pearson coefficient r < 0.50) were satisfactory. IRT showed good model fit, preserved unidimensionality, but some local dependences were observed. ConclusionThe DBS-PS shows satisfactory psychometric properties. It is easy to administer in routine practice with preoperative PD patients. It constitutes an interesting basis for cognitive restructuring before neurosurgery, by highlighting dysfunctional cognitions and measuring the benefits of cognitive restructuring therapy.

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

Less is known concerning the evolution of coping strategies before and after deep brain stimulation (DBS) in Parkinson's disease (PD) patients. 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). 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. 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 ± 5.94years, and mean disease duration was 9.89 ± 4.15years. The patients had two pre-operative psychological interviews (DBS-45days, DBS-25days) and completed the Illness Perception Questionnaire-Revised (IPQ-R) before the first interview and at DBS-1day. 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-45days, DBS-1day) 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-1day, whereas the scores were quite similar at DBS-45days. 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).

Deep brain stimulation improves central nervous system inflammation in Parkinson's disease: Evidence and perspectives.

In Parkinson's disease (PD), inflammation may lead to the degeneration of dopaminergic (DAergic) neurons. Previous studies showed that inflammatory mediators mainly contributed to this phenomenon. On the other hand, invasive neuromodulation methods such as deep brain stimulation (DBS) have better therapeutic effects for PD. One possibility is that DBS improves PD by influencing inflammation. Therefore, we further explored the mechanisms underlying inflammatory mediators and DBS in the pathogenesis of PD. We measured serum levels of two inflammatory markers, namely RANTES (regulated on activation, normal T cell expressed and secreted) and tumor necrosis factor-alpha (TNF-α), using Luminex assays in 109 preoperative DBS PD patients, 49 postoperative DBS PD patients, and 113 age- and sex-matched controls. The plasma protein data of the different groups were then statistically analyzed. RANTES (p < 0.001) and TNF-α (p=0.005) levels differed significantly between the three groups. A strong and significant correlation between RANTES levels and Hoehn-Yahr (H-Y) stage was observed in preoperative PD patients (rs =0.567, p < 0.001). Significant correlations between RANTES levels and Unified Parkinson's Disease Rating Scale III (UPDRS III) score (rs1 =0.644, p=0.033 and rs2 =0.620, p=0.042) were observed in matched patients. No correlation was observed for TNF-α levels. The results of this study indicate that PD patients have a persistent inflammatory profile, possibly via recruitment of activated monocytes, macrophages, and T lymphocytes to the central nervous system (CNS). DBS was shown to have a significant therapeutic effect on PD, which may arise by improving the inflammatory environment of the central nervous system.

Outcomes After Non-neurological Surgery in Patients With Parkinson's Disease

Patients with Parkinson disease (PD) were known to have increased risk of complications during hospitalization. The purpose of this study is to validate the global features of postoperative adverse outcomes for patients with PD.Using reimbursement claims from Taiwan's National Health Insurance Research Database, we conducted a nationwide retrospective cohort study of 6455 patients with preoperative PD receiving major surgery during 2008 to 2012. With a propensity score matching procedure, 12,910 surgical patients without PD were selected for comparison. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for 9 major postoperative complications and 30-day postoperative mortality associated with preoperative PD were calculated in the multivariate logistic regressions.Patients with PD had increased risk of postoperative pulmonary embolism (OR 2.72, 95% CI 1.45–5.10), stroke (OR 1.77, 95% CI 1.53–2.05), pneumonia (OR 1.98, 95% CI 1.70–2.31), urinary tract infection (OR 1.52, 95% CI 1.35–1.70), septicemia (OR 1.54, 95% CI 1.37–1.73), acute renal failure (OR 1.36, 95% CI 1.07–1.73), and mortality (OR 1.45, 95% CI 1.06–1.98). The association between preoperative PD and postoperative adverse events was significant in both sexes and every age group. Low income, ≥65 years of age, surgery not in medical center, highest quartile of PD medication users, and more medical conditions worsen the risk of postoperative adverse events in patients with PD.This study showed increased postoperative complications and mortality in patients with PD. Our findings suggest that revision of postoperative care protocols for this population is urgently needed.

Pre-operative obesity may influence subthalamic stimulation outcome in Parkinson's disease

BackgroundPre-operative predictive factors for optimal post-operative effect of subthalamic nucleus (STN) stimulation in Parkinson's disease (PD) have been previously reported. No study has explicitly assessed the link between excess pre-operative body weight and STN stimulation outcome. MethodsWe retrospectively compared STN stimulation outcomes of 36 PD patients with excess pre-operative body weight (group 1) and 36 matched normal-weight pre-operative (group 2) PD patients. We focused on the post-operative outcomes in the sub-group of 12 obese (group 3) PD patients. ResultsThe post-operative motor improvement and the reduction of severity of levodopa-related complications were not statistically different between groups 1 and 2 (P>0.05). In the obese group (group 3), the axial sub-score significantly improved by 29.8% in the on-drug/on-stimulation conditions whereas the improvement was not significant in the off-drug/on-stimulation condition (22.4%, P=0.20). The post-operative Mattis Dementia Rating Score was significantly reduced in group 1 and group 3. DiscussionWe considered that the post-operative axial impairment observed in the obese PD patients might be essentially consecutive to disease progression and/or post-operative DBS consequences, i.e. surgical procedure or electrical stimulation itself. Moreover, it could be argued that musculoskeletal disorders associated with obesity were responsible for the incomplete efficacy of STN stimulation on axial sub-scores, by increasing gait and balance impairment. ConclusionPre-operative obesity may be regarded as a predictive clinical factor of axial and cognitive impairment after STN-DBS.

Optimal target localization for subthalamic stimulation in patients with Parkinson disease

Objective:To further determine the causes of variable outcome from deep brain stimulation of the subthalamic nucleus (DBS-STN) in patients with Parkinson disease (PD).Methods:Data were obtained from our cohort of 309 patients with PD who underwent DBS-STN between 1996 and 2009. We examined the relationship between the 1-year motor, cognitive, and psychiatric outcomes and (1) preoperative PD clinical features, (2) MRI measures, (3) surgical procedure, and (4) locations of therapeutic contacts.Results:Pre- and postoperative results were obtained in 262 patients with PD. The best motor outcome was obtained when stimulating contacts were located within the STN as compared with the zona incerta (64% vs 49% improvement). Eighteen percent of the patients presented a postoperative cognitive decline, which was found to be principally related to the surgical procedure. Other factors predictive of poor cognitive outcome were perioperative confusion and psychosis. Nineteen patients showed a stimulation-induced hypomania, which was related to both the form of the disease (younger age, shorter disease duration, higher levodopa responsiveness) and the ventral contact location. Postoperative depression was more frequent in patients already showing preoperative depressive and/or residual axial motor symptoms.Conclusion:In this homogeneous cohort of patients with PD, we showed that (1) the STN is the best target to improve motor symptoms, (2) postoperative cognitive deficit is mainly related to the surgery itself, and (3) stimulation-induced hypomania is related to a combination of both the disease characteristics and a more ventral STN location.

The relationship between clinical phenotype and early staged bilateral deep brain stimulation in Parkinson disease

While many centers place bilateral deep brain stimulation (DBS) systems simultaneously, unilateral subthalamic nucleus (STN) DBS followed by a staged contralateral procedure has emerged as a treatment option for many patients. However, little is known about whether the preoperative phenotype predicts when staged placement of a DBS electrode in the opposite STN will be required. The authors aimed to determine whether preoperative clinical phenotype predicts early staged placement of a second STN DBS electrode in patients who undergo unilateral STN DBS for Parkinson disease (PD). Eighty-two consecutive patients with advanced PD underwent unilateral STN DBS contralateral to the most affected hemibody and had at least 2 years of follow-up. Multivariate logistic regression analysis determined preoperative characteristics that predicted staged placement of a second electrode in the opposite STN. Preoperative measurements included aspects of the Unified Parkinson's Disease Rating Scale (UPDRS), motor asymmetry index, and body weight. At 2-year follow-up, 28 (34%) of the 82 patients had undergone staged placement of a contralateral electrode while the remainder chose to continue with unilateral stimulation. Statistically significant improvements in UPDRS total and Part 3 scores were retained at the end of the 2-year follow-up period in both subsets of patients. Multivariate logistic regression analysis showed that the most important predictors for early staged placement of a second subthalamic stimulator were low asymmetry index (OR 13.4, 95% CI 2.8-64.9), high tremor subscore (OR 7.2, CI 1.5-35.0), and low body weight (OR 5.5, 95% CI 1.4-22.3). This single-center study provides evidence that elements of the preoperative PD phenotype predict whether patients will require early staged bilateral STN DBS. These data may aid in the management of patients with advanced PD who undergo STN DBS.

Medication dose reductions after pallidal versus subthalamic stimulation in patients with Parkinson’s disease

To compare the medication dose reduction between deep brain stimulation (DBS) of the globus pallidus interna (GPi) vs subthalamic nucleus (STN) in matched patients with Parkinson's disease (PD). Records of 12 patients with PD who underwent GPi-DBS at our institution from 2002 to 2008 were matched by pre-operative PD medication doses and pre-operative motor Unified Parkinson's Disease Rating Scale (UPDRS) scores to 12 cases of STN-DBS. PD medication doses were converted to levodopa equivalent doses (LEDs). GPi and STN groups had similar mean pre-operative LEDs and motor UPDRS scores. At 6 months post-DBS, there was no significant difference in percent reduction in LEDs between the GPi (47.95%) and STN (37.47%) groups (P = 0.52). The mean post-operative 'medication off/stimulation on' motor UPDRS scores did not differ significantly between GPi (15.33) and STN (16.25) groups (P = 0.74). The mean percent reduction in motor UPDRS scores was also similar between GPi (58.44%) and STN (58.98%) patients (P = 0.94). We conclude that in disease-matched patients with PD undergoing DBS, both GPi and STN may result in similar reduction in PD medication doses.

Subthalamic Nucleus Stimulation Affects Theory of Mind Network: A PET Study in Parkinson's Disease

BackgroundThere appears to be an overlap between the limbic system, which is modulated by subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD), and the brain network that mediates theory of mind (ToM). Accordingly, the aim of the present study was to investigate the effects of STN DBS on ToM of PD patients and to correlate ToM modifications with changes in glucose metabolism.Methodology/Principal FindingsTo this end, we conducted 18FDG-PET scans in 13 PD patients in pre- and post-STN DBS conditions and correlated changes in their glucose metabolism with modified performances on the Eyes test, a visual ToM task requiring them to describe thoughts or feelings conveyed by photographs of the eye region. Postoperative PD performances on this emotion recognition task were significantly worse than either preoperative PD performances or those of healthy controls (HC), whereas there was no significant difference between preoperative PD and HC. Conversely, PD patients in the postoperative condition performed within the normal range on the gender attribution task included in the Eyes test. As far as the metabolic results are concerned, there were correlations between decreased cerebral glucose metabolism and impaired ToM in several cortical areas: the bilateral cingulate gyrus (BA 31), right middle frontal gyrus (BA 8, 9 and 10), left middle frontal gyrus (BA 6), temporal lobe (fusiform gyrus, BA 20), bilateral parietal lobe (right BA 3 and right and left BA 7) and bilateral occipital lobe (BA 19). There were also correlations between increased cerebral glucose metabolism and impaired ToM in the left superior temporal gyrus (BA 22), left inferior frontal gyrus (BA 13 and BA 47) and right inferior frontal gyrus (BA 47). All these structures overlap with the brain network that mediates ToM.Conclusion/SignificanceThese results seem to confirm that STN DBS hinders the ability to infer the mental states of others and modulates a distributed network known to subtend ToM.

Recognition of emotional prosody is altered after subthalamic nucleus deep brain stimulation in Parkinson's disease

The recognition of facial emotions is impaired following subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD). These changes have been linked to a disturbance in the STN's limbic territory, which is thought to be involved in emotional processing. This was confirmed by a recent PET study where these emotional modifications were correlated with changes in glucose metabolism in different brain regions, including the amygdala and the orbitofrontal regions that are well known for their involvement in emotional processing. Nevertheless, the question as to whether these emotional changes induced by STN DBS in PD are modality-specific has yet to be answered. The objective of this study was therefore to examine the effects of STN DBS in PD on the recognition of emotional prosody.An original emotional prosody paradigm was administered to twenty-one post-operative PD patients, twenty-one pre-operative PD patients and twenty-one matched controls. Results showed that both the pre- and post-operative groups differed from the healthy controls. There was also a significant difference between the pre and post groups. More specifically, an analysis of their continuous judgments revealed that the performance of the post-operative group compared with that of the other two groups was characterized by a systematic emotional bias whereby they perceived emotions more strongly.These results suggest that the impaired recognition of emotions may not be specific to the visual modality but may also be present when emotions are expressed through the human voice, implying the involvement of the STN in the brain network underlying the recognition of emotional prosody.

Subthalamic nucleus stimulation affects subjective emotional experience in Parkinson's disease patients

A number of studies have reported impaired facial emotion recognition following subthalamic nucleus (STN) stimulation in Parkinson's disease (PD), and have related these changes to a limbic dysfunction induced by STN stimulation. The present study examined the effect of STN stimulation in PD patients on a specific component of emotion, namely the subjective experience of emotion. Thirteen post-operative PD patients, 13 pre-operative PD patients matched on clinical and neuropsychological characteristics, and 16 controls matched on age and education, were administered a validated battery of film excerpts known to primarily induce specific emotional feelings (anger, happiness, sadness, fear, disgust, and neutral), and self-rated the intensity of their emotional feelings on a discrete emotions questionnaire. The post-operative group showed a significant lower level of differentiation between the target feeling (i.e., the more likely to be reported) and non-target feelings for the film excerpts intended to induce “sadness” and “fear” respectively, as compared with the pre-operative and healthy control groups. Moreover, the post-operative group reported significantly less intense feelings of fear, anxiety and disgust for the excerpt intended to induce “fear” as compared with the pre-operative and the control groups, while no significant difference was observed between the pre-operative and control groups. Finally, the post-operative group reported significantly less intense feelings of sadness and anxiety during the excerpt intended to induce “sadness” as compared to the control group, although the differences between the pre- and post-operative groups and between the pre-operative and the control groups did not reach significance. Our study suggests that STN stimulation affects the subjective experience of emotion, thus providing a preliminary account of the modulation induced by STN stimulation of a distributed neuronal network underlying the subjective experience of emotion, although the exact contribution of the STN within such network remains to be specified.