[Show abstract][Hide abstract] ABSTRACT: Background
In the absence of a gold standard, a panel of experts can be invited to assign a reference diagnosis for use in research. Available literature offers limited guidance on assembling and working with an expert panel for this purpose. We aimed to develop a protocol for an expert panel consensus diagnosis and evaluated its applicability in a pilot project.Methods
An adjusted Delphi method was used, which started with the assessment of clinical vignettes by 3 experts individually, followed by a consensus discussion meeting to solve diagnostic discrepancies. A panel facilitator ensured that all experts were able to express their views, and encouraged the use of argumentation to arrive at a specific diagnosis, until consensus was reached by all experts. Eleven vignettes of patients suspected of having a primary neurodegenerative disease were presented to the experts. Clinical information was provided stepwise and included medical history, neurological, physical and cognitive function, brain MRI scan, and follow-up assessments over 2 years. After the consensus discussion meeting, the procedure was evaluated by the experts.ResultsThe average degree of consensus for the reference diagnosis increased from 52% after individual assessment of the vignettes to 94% after the consensus discussion meeting. Average confidence in the diagnosis after individual assessment was 85%. This did not increase after the consensus discussion meeting. The process evaluation led to several recommendations for improvement of the protocol.ConclusionA protocol for attaining a reference diagnosis based on expert panel consensus was shown feasible in research practice.
[Show abstract][Hide abstract] ABSTRACT: Peer reviewers sometimes request that authors cite their work, either appropriately or via coercive self-citation to highlight the reviewers' work. The objective of this study was to determine in peer reviews submitted to one biomedical journal (1) the extent of peer reviewer self-citation; (2) the proportion of reviews recommending revision or acceptance versus rejection that included reviewer self-citations; and (3) the proportion of reviewer self-citations versus citations to others that included a rationale.
[Show abstract][Hide abstract] ABSTRACT: Background: Serotonin (5-HT) has long been implied in the pathophysiology of Parkinson's disease (PD). In addition, the 5-HT2A receptor is associated with the regulation of motor function and mood. Objective: To assess regional 5-HT2A receptor expression in unmedicated patients with de novo PD. Methods: Eight de novo, drug naïve patients with PD and eight healthy control subjects underwent a single photon emission computed tomography (SPECT) scan with the highly selective 5-HT2A radioligand 123I-5-I-R91150. Results: In de novo PD patients 5-HT2A receptor binding was significantly reduced in the anterior striatum and the premotor cortex in PD patients compared to controls. In addition, occipital binding was elevated in PD patients. No changes in 5-HT2A receptor binding were found in the prefrontal and parietal cortex. Conclusion: In de novo PD patients, 5-HT2A receptor expression is changed in key areas of the basal ganglia-thalamocortical motor circuit and occipital cortex. This suggests altered 5-HT neurotransmission to contribute to development of PD motor and non-motor symptoms.
[Show abstract][Hide abstract] ABSTRACT: Background
Antidepressants have appeared to be more effective than placebo treatment in treating depressive syndromes in patients with Parkinson’s disease (PD).
To identify factors that predict improvement in depressive symptoms during antidepressant treatment in depressed PD patients.
A secondary analysis was performed on the dataset of the Randomized Placebo-controlled Study of Antidepressants in PD (SAD-PD), in which 76 patients received active treatment with either paroxetine or venlafaxine extended release (XR), and 39 patients received placebo treatment. Backward stepwise regression analyses were conducted with change in 24-item Hamilton Depression Rating Scale (HAMD-24) score between assessments at baseline and week 12 as the main outcome measure, and sex, age, baseline HAMD-24 score, Unified Parkinson’s Disease Rating Scale section III (UPDRS-III) score, Mini-Mental State Examination (MMSE), and the Clinical Anxiety Scale (CAS) as independent variables.
In both the active treatment and placebo groups, higher baseline HAMD-24 score and lower UPDRS-III score were associated with greater reduction in HAMD-24 score. Higher anxiety scores predicted less response in the active treatment group. Higher MMSE scores predicted greater response only in the placebo treated group. Sex and age were no predictors of response.
Higher pre-treatment depression scores and lower pre-treatment anxiety scores are the two most important predictors for improvement during antidepressant treatment in depressed PD patients, which is in line with those found in treatment studies of depressed non-PD patients. Furthermore, our results indicate the requirement for different or more intensive treatment for depressed PD patients with more severe anxiety symptoms.
Parkinsonism & Related Disorders 01/2014; · 3.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: - A multidisciplinary workgroup has revised the 2004 practice guidelines on 'Delirium' on the initiative of the Dutch Geriatrics Society.- In comparison with the previous version, the new guidelines place more emphasis on screening and non-pharmaceutical prevention and treatment. They recommend a degree of restraint when prescribing medication.- Both the patient's and the caregiver's perspectives are discussed.- The guidelines also focus on delirium in patients in a nursing home setting, and describe what the workgroup regards as optimal care for patients suffering from delirium.- The revised guidelines consider the diagnosis and treatment of delirium as a part of basic medical care and primarily the responsibility of the attending physician.- The workgroup advises consulting an expert in the field of delirium only in cases of lack of experience, and for complex cases.- The guidelines also include recommendations for the organization of follow-up care for the delirium patient.
Nederlands tijdschrift voor geneeskunde 01/2014; 158:A7822.
[Show abstract][Hide abstract] ABSTRACT: Anxiety symptoms are common in Parkinson disease (PD). Recent evidence suggests that anxiety syndromes as encountered in clinical practice may not correspond to the DSM-IV classification of anxiety disorders.
To examine the syndromal pattern of the anxiety spectrum in a large series of patients with PD, as determined with a data-driven approach using latent class analysis (LCA).
342 patients with PD were recruited from referrals to movement disorders or psychiatry clinics at six tertiary centers. Participants were assessed with a structured psychiatric interview and specific scales rating the severity of anxiety, depression, cognition and parkinsonism. The main outcome measure was classes of patients with a specific syndromal profile of anxiety symptoms based on LCA.
LCA identified four classes that were interpreted as "no anxiety or depression", "episodic anxiety without depression", "persistent anxiety with depression", and "both persistent and episodic anxiety with depression". Symptoms of persistent anxiety were almost invariably associated with symptoms of depression. There were significant differences between classes in terms of history of depression and anxiety, use of psychoactive medication, and on the Mentation and Complications sections of the Unified Parkinson Disease Rating Scale.
Patients with PD show different syndromic profiles of anxiety that do not align with the symptom profiles represented by DSM-IV anxiety disorders and major depression. Accordingly, DSM-IV criteria for anxiety disorders may not be clinically useful in PD. The different classes identified here provide empirically validated phenotypes for future research.
The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry 11/2013; · 3.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To discuss the ethical issues in the recruitment of university students as research subjects.
Narrative review and discussion.
The recruitment and inclusion of students in university research projects raise ethical issues specific to this population. Students may be required or coerced to participate, receive course credits for their participation, and their privacy may be violated. Some ethically questionable procedures are standard practice at some universities, and endorsed by their institutional review boards and faculties. Some changes will not be easy to achieve because this implies a change of organization of research and will affect funding and output.
The authors call for international standards to be set for research with students, that are in line with applicable standards in research with other subjects, such as medically ill patients, on which researchers, members of institutional review boards and editors can base their policies, opinions and decisions.
Journal of psychosomatic research 10/2013; 75(4):394-398. · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To construct a model for depression in Parkinson disease (PD) and to study the relative contribution of PD-specific and nonspecific risk factors to this model.
Structural equation modeling of direct and indirect associations of risk factors with the latent depression outcome using a cross-sectional dataset of 342 patients with PD.
A model with acceptable fit was generated that explained 41% of the variance in depression. In the final model, 3 PD-specific variables (increased disease duration, more severe motor symptoms, the use of levodopa) and 6 nonspecific variables (female sex, history of anxiety and/or depression, family history of depression, worse functioning on activities of daily living, and worse cognitive status) were maintained and significantly associated with depression. Nonspecific risk factors had a 3-times-higher influence in the model than PD-specific risk factors.
In this cross-sectional study, we showed that nonspecific factors may be more prominent markers of depression than PD-specific factors. Accordingly, research on depression in PD should focus not only on factors associated with or specific for PD, but should also examine a wider scope of factors including general risk factors for depression, not specific for PD.
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: Anxiety is a common non-motor symptom in Parkinson's disease (PD). This study analyzed the measurement properties of three frequently used anxiety scales in PD: the Beck Anxiety Inventory (BAI), the Hamilton Anxiety Rating Scale (HARS), and the Hospital Anxiety and Depression Scale-Anxiety subscale (HADS-A). METHOD: The Rasch model was applied to a multicenter international cohort of 342 patients and assessed the following aspects: fit to the Rasch model, unidimensionality, reliability, response category ordering, item local independence, differential item functioning, and scale targeting. RESULTS: In their original form, the BAI, HARS, and HADS-A, did not fit the Rasch model. A good fit to the Rasch model was only found after significant modifications, including rescoring some items and deleting those failing to fit the model. For the BAI and HADS-A, these adjustments resulted in unidimensionality. The HARS was not unidimensional and separate analyses were performed for its psychic and somatic subscales. Whereas the somatic anxiety subscale fit the Rasch model, this was achieved for the psychic anxiety subscale after modifications. CONCLUSION: None of the currently used anxiety scales display satisfactory measurement properties for assessing anxiety in PD. The results suggest the need to develop a new disease-specific scale for measuring anxiety in PD.
Journal of psychosomatic research 05/2013; 74(5):414-419. · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND AND PURPOSE: The lack of appropriate measures has hindered the research on anxiety syndromes in Parkinson's disease (PD). The objective of the present cross-sectional, international study was to identify shared elements and grouping of components from anxiety scales as a basis for designing a new scale for use in PD. METHODS: For this purpose, 342 consecutive PD patients were assessed by means of the Mini International Neuropsychiatric Inventory (depression and anxiety sections), the Clinical Global Impression of severity of the anxiety symptoms, the Hamilton Anxiety Rating Scale (HARS), the Neuropsychiatric Inventory (section E), the Beck Anxiety Inventory (BAI) and the Anxiety subscale of the Hospital Anxiety and Depression Scale (HADS-A). RESULTS: As the HADS-A showed a weak correlation with the HARS and BAI, it was not considered for more analyses. HARS and BAI exploratory factor analysis identified nine factors (62% of the variance), with only two of them combining items from both scales. Therefore, a canonical correlation model (a method to identify relations between components of two groups of variables) was built and it showed four factors grouping items from both scales: the first factor corresponded to 'generalized anxiety'; the second factor included muscular, sensory and autonomic 'non-specific somatic symptoms'; the third factor was dominated by 'respiratory symptoms'; and the fourth factor included 'cardiovascular symptoms'. CONCLUSIONS: BAI is heavily focused on panic symptoms, whilst HARS is more focused towards generalized anxiety symptoms. The new scale should include additional components in order to assess both episodic and persistent anxiety as well as items for evaluation of avoidance behaviour.
European Journal of Neurology 04/2013; · 4.16 Impact Factor