The TRACK-PD study: protocol of a longitudinal ultra-high field imaging study in Parkinson's disease.

BACKGROUND: The diagnosis of Parkinson's Disease (PD) remains a challenge and is currently based on the assessment of clinical symptoms. PD is also a heterogeneous disease with great variability in symptoms, disease course, and response to therapy. There is a general need for a better understanding of this heterogeneity and the interlinked long-term changes in brain function and structure in PD. Over the past years there is increasing interest in the value of new paradigms in Magnetic Resonance Imaging (MRI) and the potential of ultra-high field strength imaging in the diagnostic work-up of PD. With this multimodal 7 T MRI study, our objectives are: 1) To identify distinctive MRI characteristics in PD patients and to create a diagnostic tool based on these differences. 2) To correlate MRI characteristics to clinical phenotype, genetics and progression of symptoms. 3) To detect future imaging biomarkers for disease progression that could be valuable for the evaluation of new therapies. METHODS: The TRACK-PD study is a longitudinal observational study in a cohort of 130 recently diagnosed (≤ 3 years after diagnosis) PD patients and 60 age-matched healthy controls (HC). A 7 T MRI of the brain will be performed at baseline and repeated after 2 and 4 years. Complete assessment of motor, cognitive, neuropsychiatric and autonomic symptoms will be performed at baseline and follow-up visits with wearable sensors, validated questionnaires and rating scales. At baseline a blood DNA sample will also be collected. DISCUSSION: This is the first longitudinal, observational, 7 T MRI study in PD patients. With this study, an important contribution can be made to the improvement of the current diagnostic process in PD. Moreover, this study will be able to provide valuable information related to the different clinical phenotypes of PD and their correlating MRI characteristics. The long-term aim of this study is to better understand PD and develop new biomarkers for disease progression which may help new therapy development. Eventually, this may lead to predictive models for individual PD patients and towards personalized medicine in the future. TRIAL REGISTRATION: Dutch Trial Register, NL7558 . Registered March 11, 2019.

The Personalized Parkinson Project: examining disease progression through broad biomarkers in early Parkinson's disease.

BACKGROUND: Our understanding of the etiology, pathophysiology, phenotypic diversity, and progression of Parkinson's disease has stagnated. Consequently, patients do not receive the best care, leading to unnecessary disability, and to mounting costs for society. The Personalized Parkinson Project (PPP) proposes an unbiased approach to biomarker development with multiple biomarkers measured longitudinally. Our main aims are: (a) to perform a set of hypothesis-driven analyses on the comprehensive dataset, correlating established and novel biomarkers to the rate of disease progression and to treatment response; and (b) to create a widely accessible dataset for discovery of novel biomarkers and new targets for therapeutic interventions in Parkinson's disease. METHODS/DESIGN: This is a prospective, longitudinal, single-center cohort study. The cohort will comprise 650 persons with Parkinson's disease. The inclusion criteria are purposely broad: age ≥ 18 years; and disease duration ≤5 years. Participants are followed for 2 years, with three annual assessments at the study center. Outcomes include a clinical assessment (including motor and neuro-psychological tests), collection of biospecimens (stool, whole blood, and cerebrospinal fluid), magnetic resonance imaging (both structural and functional), and ECG recordings (both 12-lead and Holter). Additionally, collection of physiological and environmental data in daily life over 2 years will be enabled through the Verily Study Watch. All data are stored with polymorphic encryptions and pseudonyms, to guarantee the participants' privacy on the one hand, and to enable data sharing on the other. The data and biospecimens will become available for scientists to address Parkinson's disease-related research questions. DISCUSSION: The PPP has several distinguishing elements: all assessments are done in a single center; inclusion of "real life" subjects; deep and repeated multi-dimensional phenotyping; and continuous monitoring with a wearable device for 2 years. Also, the PPP is powered by privacy and security by design, allowing for data sharing with scientists worldwide respecting participants' privacy. The data are expected to open the way for important new insights, including identification of biomarkers to predict differences in prognosis and treatment response between patients. Our long-term aim is to improve existing treatments, develop new therapeutic approaches, and offer Parkinson's disease patients a more personalized disease management approach. TRIAL REGISTRATION: Clinical Trials NCT03364894 . Registered December 6, 2017 (retrospectively registered).

Clinical Markers of Anxiety Subtypes in Parkinson Disease.

OBJECTIVE: The aim of this work was to investigate marker profiles for proposed anxiety subtypes in Parkinson disease (PD). METHODS: We used the persistent anxiety, episodic anxiety, and avoidance behavior subscales of the Parkinson Anxiety Scale as dependent variables in multivariable linear regression analyses using a cross-sectional data set of 311 patients with PD. Independent variables consisted of a range of demographic, psychiatric, and disease-specific markers. RESULTS: In the most parsimonious model of persistent anxiety, higher Hamilton Depression Rating Scale scores, a history of anxiety, fewer years of education, lower Mini-Mental State Examination scores, lower Lawton Instrumental Activities of Daily Living scores, female sex, and complications of therapy (higher Unified Parkinson Disease Rating Scale part IV scores) were all associated with more severe persistent anxiety. Markers associated with more severe episodic anxiety included PD-specific disturbances of activities of daily living, complications of therapy, higher Hamilton Depression Rating Scale scores, female sex, and a history of anxiety. Finally, higher Hamilton Depression Rating Scale scores, a history of anxiety, complications of therapy, and longer disease duration were associated with avoidance behavior. After excluding clinically depressed patients with PD, disease severity and longer disease duration were significantly associated with episodic anxiety, but not with persistent anxiety. CONCLUSION: Persistent anxiety is mainly influenced by nonspecific markers, while episodic anxiety seems to be more PD-specific compared to persistent anxiety and may be more situational or contextual. These results provide support for possible distinct underlying constructs for anxiety subtypes in PD.

Selecting candidates for Deep Brain Stimulation in Parkinson's disease: the role of patients' expectations.

Patients with advanced Parkinson's Disease (PD) may be eligible for Deep Brain Stimulation (DBS) in case of medication-related motor fluctuations or tremor refractory to oral medication. However, several PD symptoms are unresponsive to DBS and constitute relative contra-indications for DBS. Patients referred for DBS undergo an eligibility screening during which motor functioning and contra-indications for surgery are assessed. During this pre-screening the potential benefits and drawbacks of surgery are discussed, together with patients' expectations of the results of DBS. Unrealistic expectations on the benefits of DBS may contribute to reduced patient satisfaction and poor clinical outcomes after surgery. The aim of this multicenter study (289 patients) was to assess the reasons for rejection after an outpatient-based pre-screening visit for DBS referrals, with particular emphasis on the role of patient expectations of DBS. The most frequent reason contributing to rejection was suboptimal oral treatment or satisfying symptom-control with oral medication (50% of rejections). Unrealistic expectations were identified in 38% of rejected patients and were the singular reason for rejection in 4%. Incorporating the assessment of unrealistic expectations increased the accuracy (Area Under the Curve) of determining DBS eligibility from 0.92 ((95% confidence interval (95%CI) 0.88-0.97) to 0.97 (95%CI 0.96-0.99). Patients' expectations of DBS are easily checked, and better education of patients and treating neurologists with regard to unrealistic expectations of this procedure may improve efficiency of referrals and avoid unnecessary stress and disappointments during screening.

Cognitive behavioural therapy for anxiety disorders in Parkinson's disease: Design of a randomised controlled trial to assess clinical effectiveness and changes in cerebral connectivity.

BACKGROUND: Anxiety disorders occur in up to 35% of patients with Parkinson's disease (PD) and have a negative effect on motor symptoms and quality of life. To date, no clinical trials specifically targeting anxiety in PD patients have been published. OBJECTIVE: To describe the rationale and methodology of a randomised controlled trial (RCT) that aims to study the clinical effectiveness, alterations in brain circuitry, and cost-effectiveness of cognitive behavioural therapy (CBT) for anxiety in PD. METHODS: This study is a prospective, two-centre RCT in which sixty PD patients with anxiety will be randomised to CBT treatment and clinical monitoring (intervention group) or to clinical monitoring only (control group). The CBT module used in this study was specifically developed to address symptoms of anxiety in PD patients. Participants will undergo standardised clinical, cognitive and behavioural assessment at baseline and at 2 follow-up measurements, as well as resting-state fMRI and DTI scanning before and after the intervention. The primary outcome measure is changes in severity of anxiety symptoms. Secondary outcome measures involve long-term changes in anxiety symptoms, changes in functional and structural connectivity between limbic and frontal cortices, and cost-effectiveness of the treatment. The study is registered at the ClinicalTrials.gov database under registration number NCT02648737. CONCLUSION: This study is the first that evaluates both the clinical effectiveness, cost-effectiveness, as well as the biological impact of CBT for anxiety in PD patients that, if proven effective, will hopefully contribute to a better and evidence-based approach for these non-motor symptoms.

Trajectories of recovery in depressed Parkinson's disease patients treated with paroxetine or venlafaxine.

INTRODUCTION: Depression is considered a syndrome with a constellation of symptoms that are frequently categorized into 3 domains including affective, somatic and cognitive. There has been limited research into the domain specific magnitude or relative timing of treatment response in patients with Parkinson's disease (PD). In addition, antidepressant trials involving patients with PD have demonstrated a similar robust placebo response to that seen in other populations. However, the timing of the placebo response has not been carefully studied. METHODS: We studied differential responses to antidepressant treatment in affective, somatic and cognitive domains of depression. Patients were treated for twelve weeks with placebo, venlafaxine or paroxetine as part of the Study of Antidepressants in Parkinson's Disease (SAD-PD) randomized controlled trial. Depressive symptoms were evaluated with three commonly used rating scales. RESULTS: All symptom domains improved during the study period, There was a significant placebo effect, especially in the first two weeks that had diminished by week 12. Compared to placebo, the affective symptoms significantly improved during treatment as early as week 4, followed by the somatic symptoms of depression in week 6 and cognitive symptoms in week 8. The largest response was seen in the affective domain. CONCLUSION: In depressed PD patients treated with venlafaxine or paroxetine, affective symptoms improved first, followed by somatic symptoms and cognitive symptoms. These findings could guide patient counselling and increase patient compliance by informing about the expected treatment responses. The substantial placebo effect underlines the importance of a sufficiently long study period in future studies.

Factor analysis of the Hamilton Depression Rating Scale in Parkinson's disease.

INTRODUCTION: Several studies have validated the Hamilton Depression Rating Scale (HAMD) in patients with Parkinson's disease (PD), and reported adequate reliability and construct validity. However, the factorial validity of the HAMD has not yet been investigated. The aim of our analysis was to explore the factor structure of the HAMD in a large sample of PD patients. METHODS: A principal component analysis of the 17-item HAMD was performed on data of 341 PD patients, available from a previous cross sectional study on anxiety. An eigenvalue ≥1 was used to determine the number of factors. Factor loadings ≥0.4 in combination with oblique rotations were used to identify which variables made up the factors. Kaiser-Meyer-Olkin measure (KMO), Cronbach's alpha, Bartlett's test, communality, percentage of non-redundant residuals and the component correlation matrix were computed to assess factor validity. RESULTS: KMO verified the sample's adequacy for factor analysis and Cronbach's alpha indicated a good internal consistency of the total scale. Six factors had eigenvalues ≥1 and together explained 59.19% of the variance. The number of items per factor varied from 1 to 6. Inter-item correlations within each component were low. There was a high percentage of non-redundant residuals and low communality. CONCLUSION: This analysis demonstrates that the factorial validity of the HAMD in PD is unsatisfactory. This implies that the scale is not appropriate for studying specific symptom domains of depression based on factorial structure in a PD population.

Siglec-7 specifically recognizes Campylobacter jejuni strains associated with oculomotor weakness in Guillain-Barré syndrome and Miller Fisher syndrome.

Due to molecular mimicry, Campylobacter jejuni lipo-oligosaccharides can induce a cross-reactive antibody response to nerve gangliosides, which leads to Guillain-Barré syndrome (GBS). Cross-reactive antibodies to ganglioside GQ1b are strongly associated with oculomotor weakness in GBS and its variant, Miller Fisher syndrome (MFS). Antigen recognition is a crucial first step in the induction of a cross-reactive antibody response, and it has been shown that GQ1b-like epitopes expressed on the surface of C. jejuni are recognized by sialic acid-binding immunoglobulin-like lectin-7 (Siglec-7). We aimed to determine the epitope specificity of C. jejuni binding to Siglec-7, and correlate the outcome to disease symptoms in GBS and MFS patients. Using a well-defined GBS/MFS-associated C. jejuni strain collection, which included three sialic acid knockout strains, we found that Siglec-7 exclusively binds to C. jejuni strains that express terminal disialylated ganglioside mimics. When serological and diagnostic patient records were correlated with the Siglec-7-binding properties, we observed an association between Siglec-7 binding and the presence of anti-GQ1b antibodies in patient serum. In addition, Siglec-7 binding was associated with oculomotor weakness in GBS and MFS patients. Lipo-oligosaccharide-specific binding of C. jejuni to Siglec-7 may be an initiating event in immune recognition and presentation, and lead to anti-GQ1b antibody production and the development of ocular weakness in GBS or MFS.

Detection of anti-MAG antibodies in polyneuropathy associated with IgM monoclonal gammopathy.

BACKGROUND: Detection of serum antibodies to myelin-associated glycoprotein (MAG) by Western blot (WB) is a valuable assay to diagnose a distinct type of demyelinating polyneuropathy with immunoglobulin M (IgM) monoclonal gammopathy. In this study, the diagnostic accuracy of a new and more practical ELISA to detect these antibodies was validated. METHODS: Routine WBs from 2 independent laboratories and ELISA were used to detect anti-MAG IgM in serum from 207 patients with neuropathy and controls. The sensitivity and specificity of these assays were compared and related to the patient clinical and electrophysiologic characteristics. RESULTS: In ELISA, anti-MAG antibodies were found in serum from 49 (72%) of 68 patients with demyelinating polyneuropathy and IgM monoclonal gammopathy. However, in this subgroup of patients, only 30 (44%) and 37 (54%) were positive in the 2 WBs. All of the patients positive in the 2 WBs were also positive in ELISA. A high correlation was found for IgM activity in ELISA to MAG and sulfate-3-glucuronyl paragloboside (SGPG) (Spearman rho = 0.72, p < 0.0001), supporting the notion that the shared sulfated glucuronic acid moiety of MAG and SGPG is preserved. Most patients positive in anti-MAG ELISA had a slowly progressive sensory-motor demyelinating polyneuropathy, even if the WB was negative. In control groups, however, 4 WB-negative patients with a nondemyelinating monoclonal gammopathy-related polyneuropathy were positive in anti-MAG ELISA. The remaining samples were negative in ELISA. CONCLUSION: ELISA is more sensitive than Western blot to diagnose anti-myelin-associated glycoprotein related polyneuropathy, although a positive serology may be found in other forms of polyneuropathy as well.

Granzyme expression in fine-needle aspirates from liver allografts is increased during acute rejection.

We investigated whether determination in fine-needle aspiration biopsy (FNAB) specimens of cells expressing granzymes (Grs) and Fas ligand would provide a reliable, easy, and quantitative measure of rejection activity in the transplanted liver. Retrospectively, 13 FNAB specimens obtained during clinical acute rejection, 10 FNAB specimens obtained during subclinical rejection, 12 FNAB specimens obtained during cytomegalovirus (CMV) infection, and 26 FNAB specimens obtained in the absence of rejection or infection were included on the study. Cytospin preparations of FNAB and peripheral-blood specimens were immunocytochemically stained for Fas-ligand and Gr, and increments in the liver were calculated by subtracting frequencies of positive cells in blood from those in FNAB specimens. Only sporadically Fas ligand-expressing, but many Gr-expressing, cells were detected in FNAB specimens. Increments in Gr-positive (Gr(+)) cells were significantly greater in FNAB specimens obtained during clinical rejection (median, 70 Gr(+) cells; range, 0 to 312 Gr(+) cells; P = .006) and tended to be greater in FNAB specimens obtained during subclinical rejection (median, 62 Gr(+) cells; range, 5 to 113 Gr(+) cells; P = .09) compared with those obtained in the absence of rejection (median, 16 Gr(+) cells; range, 0 to 103 Gr(+) cells). Increments obtained during clinical or subclinical rejection did not differ from those obtained during CMV infection (median, 27 Gr(+) cells; range, 6 to 212 Gr(+) cells). With the exclusion of specimens obtained during CMV infection, the sensitivity of Gr determination in FNAB specimens for the diagnosis of acute rejection (either clinical or subclinical) was 70%, and specificity, 69%. In FNAB specimens obtained during clinical and subclinical acute rejection episodes after liver transplantation, increased numbers of Gr-expressing cells were present; in the absence of CMV infection, their quantification provides a measure for rejection activity with moderate accuracy.