Identification of prodromal presentations of Parkinson's disease among primary care outpatients in Germany

Background: This study aimed to identify clinical features that predate the diagnosis of PD in a primary care setting. Methods: This retrospective case-control study was based on data from the Disease Analyzer database (IQVIA) and included 17,702 patients with Parkinson's disease and 17,702 non-PD controls matched for age, sex, and index year. We analyzed the prevalence of 15 defined diagnoses and symptoms documented within 2 years, ≥2 to <5, and ≥5 to <10 years prior to the index date in patients with and without PD. Logistic regression analyses were conducted to assess the association between PD and the predefined diagnoses. Results: The prevalence of motor, neuropsychiatric and autonomic features was higher in those with a later diagnosis of Parkinson's disease than controls for all three periods except for rigidity in the ≥2 to <5 and ≥5 to <10-year periods and erectile dysfunction in the most recent period before diagnosis. The clinical presentation recorded in the greatest percentage of patients was depression, followed by dizziness, insomnia, and constipation, but these were also common in the control population. The odds ratios were highest for increase in tremor, followed by balance impairment and memory problems, particularly in the latest period before diagnosis, and by constipation particularly in the earliest period examined. Conclusion: The prodromal features of PD could be identified in this large primary care database in Germany with similar results to those found in previous database studies despite differences in methodologies and systems

A forensic case of hydranencephaly in a preterm neonate fully documented by postmortem imaging techniques.

The authors present a medico-legal autopsy case of hydranencephaly in a male preterm newborn, fully documented by postmortem unenhanced and enhanced imaging techniques (postmortem computed tomography and postmortem magnetic resonance imaging). Hydranencephaly is a congenital anomaly of the central nervous system, consisting in almost complete absence of the cerebral hemispheres and replacement of the cerebral parenchyma by cerebrospinal fluid, rarely encountered in forensic medical practice. A premature baby was born during the supposed 22nd and 24th week of pregnancy in the context of a denial of pregnancy without any follow-up. The newborn died a few hours after birth and medico-legal investigations were requested to determine the cause of death and exclude the intervention of a third person in the lethal process. The external examination revealed neither traumatic nor malformative lesions. Postmortem imaging investigations were typical of hydranencephaly, and conventional medico-legal autopsy, neuropathological examination, and histological examination confirmed a massive necrotic-haemorrhagic hydranencephaly. This case represents in itself an association of out-of-the-ordinary elements making it worthy of interest. Postmortem unenhanced and enhanced imaging techniques (computed tomography and magnetic resonance imaging) were performed as complementary examination to conventional medico-legal investigations.Postmortem angiography of a preterm newborn is possible with catheterization of the umbilical blood vessels.Hydranencephaly is a congenital anomaly of the central nervous system, consisting in almost complete absence of the cerebral hemispheres and replacement of the brain by cerebrospinal fluid, for which several aetiologies have been postulated

Finite size corrections to random Boolean networks

Since their introduction, Boolean networks have been traditionally studied in view of their rich dynamical behavior under different update protocols and for their qualitative analogy with cell regulatory networks. More recently, tools borrowed from statistical physics of disordered systems and from computer science have provided a more complete characterization of their equilibrium behavior. However, the largest part of the results have been obtained in the thermodynamic limit, which is often far from being reached when dealing with realistic instances of the problem. The numerical analysis presented here aims at comparing - for a specific family of models - the outcomes given by the heuristic belief propagation algorithm with those given by exhaustive enumeration. In the second part of the paper some analytical considerations on the validity of the annealed approximation are discussed.Comment: Minor correction

Caregiver Burden in Late-Stage Parkinsonism and Its Associations

Background: Patients in the late stages of parkinsonism are highly dependent on others in their self-care and activities of daily living. However, few studies have assessed the physical, psychological and social consequences of caring for a person with late-stage parkinsonism. Patients and methods: Five hundred and six patients and their caregivers from the Care of Late Stage Parkinsonism (CLaSP) study were included. Patients’ motor and non-motor symptoms were assessed using the UPDRS and Non-motor symptom scale (NMSS), Neuropsychiatric inventory (NPI-12), and caregivers’ health status using the EQ-5D-3 L. Caregiver burden was assessed by the Zarit Burden Interview (ZBI). Results: The majority of caregivers were the spouse or life partner (71.2%), and were living with the patient at home (67%). Approximately half of caregivers reported anxiety/depression and pain/discomfort (45% and 59% respectively). The factors most strongly associated with caregiver burden were patients’ neuropsychiatric features on the total NPI score (r = 0.38, p < 0.0001), total NMSS score (r = 0.28, p < 0.0001), caring for male patients and patients living at home. Being the spouse, the hours per day assisting and supervising the patient as well as caregivers’ EQ-5D mood and pain scores were also associated with higher ZBI scores (all p < 0.001). Conclusion: The care of patients with late stage parkinsonism is associated with significant caregiver burden, particularly when patients manifest many neuropsychiatric and non-motor features and when caring for a male patient at home

Assessing cognitive dysfunction in Parkinson's disease: An online tool to detect visuo-perceptual deficits.

BackgroundPeople with Parkinson's disease (PD) who develop visuo-perceptual deficits are at higher risk of dementia, but we lack tests that detect subtle visuo-perceptual deficits and can be performed by untrained personnel. Hallucinations are associated with cognitive impairment and typically involve perception of complex objects. Changes in object perception may therefore be a sensitive marker of visuo-perceptual deficits in PD.ObjectiveWe developed an online platform to test visuo-perceptual function. We hypothesised that (1) visuo-perceptual deficits in PD could be detected using online tests, (2) object perception would be preferentially affected, and (3) these deficits would be caused by changes in perception rather than response bias.MethodsWe assessed 91 people with PD and 275 controls. Performance was compared using classical frequentist statistics. We then fitted a hierarchical Bayesian signal detection theory model to a subset of tasks.ResultsPeople with PD were worse than controls at object recognition, showing no deficits in other visuo-perceptual tests. Specifically, they were worse at identifying skewed images (P &lt; .0001); at detecting hidden objects (P = .0039); at identifying objects in peripheral vision (P &lt; .0001); and at detecting biological motion (P = .0065). In contrast, people with PD were not worse at mental rotation or subjective size perception. Using signal detection modelling, we found this effect was driven by change in perceptual sensitivity rather than response bias.ConclusionsOnline tests can detect visuo-perceptual deficits in people with PD, with object recognition particularly affected. Ultimately, visuo-perceptual tests may be developed to identify at-risk patients for clinical trials to slow PD dementia. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society

Delivering Optimal Care to People with Cognitive Impairment in Parkinson’s Disease: A Qualitative Study of Patient, Caregiver, and Professional Perspectives

Background: Cognitive impairment is common in Parkinson’s disease (PD) and associated with lower quality of life. Cognitive impairment in PD manifests differently to other dementia pathologies. Provision of optimal care requires knowledge about the support needs of this population. // Methods: Eleven people with PD and cognitive impairment (PwP), 10 family caregivers, and 27 healthcare professionals were purposively sampled from across the United Kingdom. Semistructured interviews were conducted in 2019–2021, audio-recorded, transcribed, and analysed using reflexive thematic analysis. // Results: Cognitive impairment in PD conveyed increased complexity for clinical management and healthcare interactions, the latter driven by multifactorial communication difficulties. Techniques that helped included slow, simple, and single messages, avoiding topic switching. Information and emotional support needs were often unmet, particularly for caregivers. Diagnostic pathways were inconsistent and awareness of cognitive impairment in PD was poor, both contributing to underdiagnosis. Many felt that PwP and cognitive impairment fell through service gaps, resulting from disjointed, nonspecific, and underresourced services. Personalised care was advocated through tailoring to individual needs of PwP and caregivers facilitated by flexibility, time and continuity within services, and supporting self-management. // Conclusions: This study highlights unmet need for people with this complex condition. Clinicians should adapt their approach and communication techniques for this population and provide tailored information and support to both PwP and caregivers. Services need to be more streamlined and collaborative, providing more time and flexibility. There is a need for wider awareness and deeper understanding of this condition and its differences from other types of dementia

Repositioning the Catalytic Triad Aspartic Acid of Haloalkane Dehalogenase: Effects on Stability, Kinetics, and Structure

Haloalkane dehalogenase (DhlA) catalyzes the hydrolysis of haloalkanes via an alkyl-enzyme intermediate. The covalent intermediate, which is formed by nucleophilic substitution with Asp124, is hydrolyzed by a water molecule that is activated by His289. The role of Asp260, which is the third member of the catalytic triad, was studied by site-directed mutagenesis. Mutation of Asp260 to asparagine resulted in a catalytically inactive D260N mutant, which demonstrates that the triad acid Asp260 is essential for dehalogenase activity. Furthermore, Asp260 has an important structural role, since the D260N enzyme accumulated mainly in inclusion bodies during expression, and neither substrate nor product could bind in the active-site cavity. Activity for brominated substrates was restored to D260N by replacing Asn148 with an aspartic or glutamic acid. Both double mutants D260N+N148D and D260N+N148E had a 10-fold reduced kcat and 40-fold higher Km values for 1,2-dibromoethane compared to the wild-type enzyme. Pre-steady-state kinetic analysis of the D260N+N148E double mutant showed that the decrease in kcat was mainly caused by a 220-fold reduction of the rate of carbon-bromine bond cleavage and a 10-fold decrease in the rate of hydrolysis of the alkyl-enzyme intermediate. On the other hand, bromide was released 12-fold faster and via a different pathway than in the wild-type enzyme. Molecular modeling of the mutant showed that Glu148 indeed could take over the interaction with His289 and that there was a change in charge distribution in the tunnel region that connects the active site with the solvent. On the basis of primary structure similarity between DhlA and other α/β-hydrolase fold dehalogenases, we propose that a conserved acidic residue at the equivalent position of Asn148 in DhlA is the third catalytic triad residue in the latter enzymes.