Pimavanserin, a novel antipsychotic for management of Parkinson's disease psychosis

Neurophysiological treatment effects of mesdopetam, pimavanserin and clozapine in a rodent model of Parkinson's disease psychosis

Psychosis in Parkinson's disease is a common phenomenon associated with poor outcomes. To clarify the pathophysiology of this condition and the mechanisms of antipsychotic treatments, we have here characterized the neurophysiological brain states induced by clozapine, pimavanserin, and the novel prospective antipsychotic mesdopetam in a rodent model of Parkinson's disease psychosis, based on chronic dopaminergic denervation by 6-OHDA lesions, levodopa priming, and the acute administration of an NMDA antagonist. Parallel recordings of local field potentials from eleven cortical and sub-cortical regions revealed shared neurophysiological treatment effects for the three compounds, despite their different pharmacological profiles, involving reversal of features associated with the psychotomimetic state, such as a reduction of aberrant high-frequency oscillations in prefrontal structures together with a decrease of abnormal synchronization between different brain regions. Other drug-induced neurophysiological features were more specific to each treatment, affecting network oscillation frequencies and entropy, pointing to discrete differences in mechanisms of action. These findings indicate that neurophysiological characterization of brain states is particularly informative when evaluating therapeutic mechanisms in conditions involving symptoms that are difficult to assess in rodents such as psychosis, and that mesdopetam should be further explored as a potential novel antipsychotic treatment option for Parkinson psychosis.

Pimavanserin Use in Lewy Body Dementia: A Case Report Demonstrating the Medication's Efficacy

Pimavanserin is an antipsychotic that is approved for use in Parkinson's disease psychosis. Working as a serotonin 2A inverse agonist, pimavanserin allows patients to improve their psychotic symptoms without worsening the motor symptoms of Parkinson's. This mechanism is mediated via serotonin receptors and may allow for pimavanserin to be considered for use in other disease processes that present with psychosis. Here, the authors describe the case of a 75-year-old man with Lewy Body Dementia (LBD) who was started on pimavanserin. The response of the patient to the medication was measured over a six-week time course using the Scales for the Assessment of Positive Symptoms of Schizophrenia (SAPS). Overall, pimavanserin was shown to be effective in this patient with LBD. The authors also provide a review of the sparse literature attesting to other off-label uses for this unique antipsychotic.

Reverse Engineering Drugs: Lorcaserin as an Example

Novel central nervous system (CNS)-based therapies have been difficult to produce due to the complexity of the brain, limited knowledge of CNS-based disease development and associated pathways, difficulty in penetrating the blood brain barrier, and a lack of reliable biomarkers of disease. Reverse engineering in drug development allows the utilization of new knowledge of disease pathways and the use of innovative technology to develop medications with enhanced efficacy and reduced toxicities. Lorcaserin was developed as a specific 5HT_2C serotonin receptor agonist for the treatment of obesity with limited off-target effects at the 5HT_2A and 5HT_2B receptors. This receptor specificity limited the hallucinogenic and cardiovascular side effects noted with other serotonin receptor agonists. Reverse engineering approaches to drug development reduce the cost of producing new medications, identify specific populations of patients that will derive the most benefit from therapy, and produce novel therapies with greater efficacy and limited toxicity.

Mortality in Patients with Parkinson's Disease-Related Psychosis Treated with Pimavanserin Compared with Other Atypical Antipsychotics: A Cohort Study

INTRODUCTION

Pimavanserin is approved in the USA to treat hallucinations and delusions associated with Parkinson's disease psychosis (PDP).

OBJECTIVES

We evaluated mortality in patients with PDP after initiation of pimavanserin or comparator atypical antipsychotics, overall, over time, and across subgroups.

METHODS

A cohort of patients aged ≥65 years in the USA with PDP newly initiating pimavanserin or a comparator atypical antipsychotic (clozapine, quetiapine, risperidone, olanzapine, aripiprazole, brexpiprazole) was identified in 2016-2019 Medicare claims data. All-cause mortality in the propensity score-matched treatment groups was compared with hazard ratios (HRs) and 95% confidence intervals (CIs) estimated with Cox-proportional hazards models. Cumulative incidence curves and time period-specific models evaluated risk over time. Subgroup and sensitivity analyses were performed, including a sub-cohort of long-term care (LTC) or skilled nursing facility (SNF) residents.

RESULTS

We identified 2892 pimavanserin initiators and 19,083 comparator initiators (overall 47% female, mean age = 80.9 years, LTC/SNF residents = 30%). Before matching, pimavanserin users had fewer severe comorbidities and more anti-Parkinson medication use than comparators. Matching resulted in 2891 patients in both groups, and all covariates were well balanced. In the matched cohort, the HR for mortality for pimavanserin versus comparator was 0.78 (95% CI 0.67-0.91), with the lowest time period-specific HRs in the first 180 days. Hazard ratios were similar across sensitivity analyses and subgroups. In LTC/SNF residents, the HR was 0.78 (95% CI 0.60-1.01).

CONCLUSION

The observed mortality rates were lower among patients treated with pimavanserin compared with those treated with other atypical antipsychotics.

STUDY REGISTRATION

European Union Post-authorization Study (EU PAS) register number 46331.

Surgical Management of Synucleinopathies

Synucleinopathies represent a diverse set of pathologies with significant morbidity and mortality. In this review, we highlight the surgical management of three synucleinopathies: Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). After examining underlying molecular mechanisms and the medical management of these diseases, we explore the role of deep brain stimulation (DBS) in the treatment of synuclein pathophysiology. Further, we examine the utility of focused ultrasound (FUS) in the treatment of synucleinopathies such as PD, including its role in blood–brain barrier (BBB) opening for the delivery of novel drug therapeutics and gene therapy vectors. We also discuss other recent advances in the surgical management of MSA and DLB. Together, we give a diverse overview of current techniques in the neurosurgical management of these pathologies.

Emerging role of psychosis in Parkinson's disease: From clinical relevance to molecular mechanisms

Parkinson’s disease (PD) is the second most common neurodegenerative disease. Psychosis is one of the common psychiatric presentations in the natural course of PD. PD psychosis is an important non-motor symptom, which is strongly correlated with a poor prognosis. Increasing attention is being given to PD psychosis. In this opinion review, we summarized and analyzed the identification, screening, epidemiology, mechanisms, risk factors, and therapeutic approaches of PD psychosis based on the current clinical evidence. PD psychosis tends to have a negative effect on patients' quality of life and increases the burden of family caregiving. Screening and identification in the early stage of disease is crucial for establishing tailored therapeutic strategies and predicting the long-term outcome. Development of PD psychosis is believed to involve a combination of exogenous and endogenous mechanisms including imbalance of neurotransmitters, structural and network changes, genetic profiles, cognitive impairment, and antiparkinsonian medications. The therapeutic strategy for PD psychosis includes reducing or ceasing the use of dopaminergic drug, antipsychotics, cholinesterase inhibitors, and non-pharmacological interventions. Ongoing clinical trials are expected to provide new insights for tailoring therapy for PD psychosis. Future research based on novel biomarkers and genetic factors may help inform individualized therapeutic strategies.

Identification of Potential Parkinson's Disease Drugs Based on Multi-Source Data Fusion and Convolutional Neural Network

Parkinson’s disease (PD) is a serious neurodegenerative disease. Most of the current treatment can only alleviate symptoms, but not stop the progress of the disease. Therefore, it is crucial to find medicines to completely cure PD. Finding new indications of existing drugs through drug repositioning can not only reduce risk and cost, but also improve research and development efficiently. A drug repurposing method was proposed to identify potential Parkinson’s disease-related drugs based on multi-source data integration and convolutional neural network. Multi-source data were used to construct similarity networks, and topology information were utilized to characterize drugs and PD-associated proteins. Then, diffusion component analysis method was employed to reduce the feature dimension. Finally, a convolutional neural network model was constructed to identify potential associations between existing drugs and LProts (PD-associated proteins). Based on 10-fold cross-validation, the developed method achieved an accuracy of 91.57%, specificity of 87.24%, sensitivity of 95.27%, Matthews correlation coefficient of 0.8304, area under the receiver operating characteristic curve of 0.9731 and area under the precision–recall curve of 0.9727, respectively. Compared with the state-of-the-art approaches, the current method demonstrates superiority in some aspects, such as sensitivity, accuracy, robustness, etc. In addition, some of the predicted potential PD therapeutics through molecular docking further proved that they can exert their efficacy by acting on the known targets of PD, and may be potential PD therapeutic drugs for further experimental research. It is anticipated that the current method may be considered as a powerful tool for drug repurposing and pathological mechanism studies.

Psychosis in Parkinson's Disease: A Lesson from Genetics

Psychosis in Parkinson's disease (PDP) represents a common and debilitating condition that complicates Parkinson's disease (PD), mainly in the later stages. The spectrum of psychotic symptoms are heterogeneous, ranging from minor phenomena of mild illusions, passage hallucinations and sense of presence to severe psychosis consisting of visual hallucinations (and rarely, auditory and tactile or gustatory) and paranoid delusions. PDP is associated with increased caregiver stress, poorer quality of life for patients and carers, reduced survival and risk of institutionalization with a significant burden on the healthcare system. Although several risk factors for PDP development have been identified, such as aging, sleep disturbances, long history of PD, cognitive impairment, depression and visual disorders, the pathophysiology of psychosis in PD is complex and still insufficiently clarified. Additionally, several drugs used to treat PD can aggravate or even precipitate PDP. Herein, we reviewed and critically analyzed recent studies exploring the genetic architecture of psychosis in PD in order to further understand the pathophysiology of PDP, the risk factors as well as the most suitable therapeutic strategies.

The impact of pimavanserin on psychotic phenotypes and tau phosphorylation in the P301L/COMT- and rTg(P301L)4510 mouse models of Alzheimer's disease

INTRODUCTION

Psychosis in Alzheimer's disease (AD) is associated with grave clinical consequences including a precipitous cognitive decline and a hastened demise. These outcomes are aggravated by use of existing antipsychotic medications, which are also associated with cognitive decline and increased mortality; preclinical models that would develop new therapeutic approaches are desperately needed. The current report evaluates the ability of the neoteric antipsychotic, pimavanserin, to normalize hyperkinesis and sensorimotor gating in the novel catechol-O-methyltransferase (COMT) deleted P301L/COMT- and rTg(P301L)4510 models of psychotic AD, and the impact of pimavanserin on tau pathology.

METHODS

Female P301L/COMT- mice were behaviorally characterized for abnormalities of locomotion and sensorimotor gating, and biochemically characterized for patterns of tau phosphorylation relative to relevant controls utilizing high-sensitivity tau enzyme-linked immunosorbent assay (ELISA). Female P301L/COMT- and rTg(P301L)4510 mice were randomized to pimavanserin or vehicle treatment to study the ability of pimavanserin to normalize locomotion and rescue sensorimotor gating. Additionally, high-sensitivity tau ELISA was used to investigate the impact of treatment on tau phosphorylation.

RESULTS

P301L/COMT- mice evidenced a hyperlocomotive phenotype and deficits of sensorimotor gating relative to wild-type mice on the same background, and increased tau phosphorylation relative to COMT-competent P301L mice. Pimavanserin normalized the hyperkinetic phenotype in both the P301L/COMT- and rTg(P301L)4510 mice but had no impact on sensorimotor gating in either model. Pimavanserin treatment had little impact on tau phosphorylation patterns.

DISCUSSION

These data suggest that pimavanserin ameliorates tau-driven excessive locomotion. Given the morbidity associated with aberrant motor behaviors such as pacing in AD and lack of effective treatments, future studies of the impact of pimavanserin on actigraphy in patients with this syndrome may be warranted.

Falls and Fractures in Patients with Parkinson's Disease-Related Psychosis Treated with Pimavanserin vs Atypical Antipsychotics: A Cohort Study

Background

Parkinson’s disease-related psychosis increases patients’ risk of falls. Pimavanserin is an atypical antipsychotic approved in the USA in 2016 for the treatment of hallucinations and delusions associated with Parkinson’s disease-related psychosis.

Objective

We aimed to compare the risk of falls/fractures among patients with Parkinson’s disease-related psychosis treated with pimavanserin vs other atypical antipsychotics.

Patients and Methods

We identified a cohort of patients with Parkinson’s disease-related psychosis aged ≥ 40 years initiating either pimavanserin or a comparator antipsychotic (clozapine, quetiapine, risperidone, olanzapine, aripiprazole, brexpiprazole) in US commercial insurance and supplementary Medicare claims (2015–2019). Comparators were propensity score matched 2:1 with pimavanserin initiators; incidence rates of falls/fractures were compared using incidence rate ratios (IRRs) and 95% confidence intervals (CIs).

Results

We identified 112 eligible pimavanserin initiators and 982 comparators. Pimavanserin initiators were younger and had fewer severe comorbidities, indicators of impairment, and healthcare encounters, though they had higher Parkinson’s disease medication use. The crude incidence rates [cases/100 person-years] (95% CI) for composite falls/fractures were 17.8 (7.7–35.0) for pimavanserin and 40.8 (35.0–47.4) for comparators. Matching retained 108 pimavanserin initiators and 216 comparators—all characteristics were well balanced after matching—with a matched IRR (pimavanserin vs comparator) of 0.71 (95% CI 0.27–1.67). Sensitivity analysis IRR estimates were consistently below 1.00, with a sensitivity analysis not requiring a diagnosis of psychosis resulting in an IRR estimate of 0.55 (95% CI 0.34–0.86).

Conclusions

The results of this study do not suggest an increase in the risk of falls or fractures associated with pimavanserin compared with other antipsychotics in patients with Parkinson’s disease-related psychosis. Sensitivity analyses suggest a decreased risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00284-1.

The protective effects of Pimavanserin against cerebral ischemia-induced brain injury

The integrity of the blood-brain barrier (BBB) is mainly maintained by the brain vascular endothelial cells and the tight junctions amongst them. Pimavanserin is a novel agent approved for the treatment of Parkinson’s disease and exerts neuroprotective properties. The present study aims to explore the possibility that Pimavanserin might be an effective agent used for the treatment of cerebral ischemia stroke. Middle cerebral artery occlusion (MCAO) was established in mice, and oxygen-glucose deprivation/reoxygenation (OGD/R) was established in brain bEND.3 endothelial cells. Mice were randomly divided into four groups: (1) Sham operation group; (2). Pimavanserin (1 mg/kg); (3). MCAO; (4). Pimavanserin+ MCAO. We found that compared to the Sham group, the elevated neurological deficit score and brain water content increased production of inflammatory factors, increased BBB permeability, and downregulated Claudin 5 expression were observed in the MCAO group and were all dramatically reversed by the administration of Pimavanserin. Brain bEND.3 endothelial cells were treated with Pimavanserin before the exposure to OGD/R. The significantly increased lactate dehydrogenase (LDH) release, declined cell viability, increased endothelial permeability, downregulated Claudin 5 and Krüppel-like factors 6 (KLF6) were observed in the OGD/R group and were all reversed by the introduction of Pimavanserin. Lastly, the effects of Pimavanserin on the expression level of Claudin 5 and endothelial permeability in OGD/R-challenged endothelial cells were both abolished by the knockdown of KLF6. Taken together, our data revealed that Pimavanserin protected against cerebral ischemia injury by regulating the BBB integrity in a KLF6-dependent manner.

Istradefylline - a first generation adenosine A2A antagonist for the treatment of Parkinson's disease

Introduction It is now accepted that Parkinson's disease (PD) is not simply due to dopaminergic dysfunction, and there is interest in developing non-dopaminergic approaches to disease management. Adenosine A_2A receptor antagonists represent a new way forward in the symptomatic treatment of PD.Areas covered In this narrative review, we summarize the literature supporting the utility of adenosine A_2A antagonists in PD with a specific focus on istradefylline, the most studied and only adenosine A_2A antagonist currently in clinical use.Expert opinion: At this time, the use of istradefylline in the treatment of PD is limited to the management of motor fluctuations as supported by the results of randomized clinical trials and evaluation by Japanese and USA regulatory authorities. The relatively complicated clinical development of istradefylline was based on classically designed studies conducted in PD patients with motor fluctuations on an optimized regimen of levodopa plus adjunctive dopaminergic medications. In animal models, there is consensus that a more robust effect of istradefylline in improving motor function is produced when combined with low or threshold doses of levodopa rather than with high doses that produce maximal dopaminergic improvement. Exploration of istradefylline as a 'levodopa sparing' strategy in earlier PD would seem warranted.

Increased risk of falls and fractures in patients with psychosis and Parkinson disease

Objective

Evaluate whether the risk of falls and fractures differs between patients with Parkinson disease with psychosis (PDP) and patients with Parkinson disease (PD) without psychosis at similar disease stages.

Methods

Patients with PD without psychosis were identified in the Medicare claims databases (2008–2018) and followed from the first PD diagnosis date during the study period. Patients with a subsequent diagnosis of psychosis were included in the PDP group. Patients with PDP and PD without psychosis were propensity score-matched based on characteristics within blocks of time since cohort entry. The incidence rates (IRs), expressed per 100 person-years, and 95% confidence intervals (CIs) of falls and fractures were evaluated as composite and separate outcomes. Incidence rate ratios (IRRs) were used to compare patients with PDP and PD without psychosis in the matched cohort.

Results

154,306 patients had PD without psychosis and no falls or fractures before cohort entry; the IR for falls and fractures was 11.41 events (95% CI, 11.29–11.53). 12,127 patients (7.8%) had a subsequent PDP diagnosis. PDP patients had a higher prevalence of most comorbidities and risk factors for falls and fractures than those without psychosis. The crude IR for falls and fractures among PDP patients was 29.03 events (95% CI, 28.27–29.81). PD without psychosis and PDP groups had more falls than fractures. After matching, 24,144 PD patients without psychosis (15.6%) and 12,077 PDP patients (99.6%) were retained. Matched PDP patients had a higher incidence of falls and fractures than PD patients without psychosis (IRR = 1.44; 95% CI, 1.39–1.49). The higher increased rate was noted separately for falls (IRR = 1.48; 95% CI, 1.43–1.54) and any fractures (IRR = 1.17; 95% CI, 1.08–1.27) as well as within specific types of fracture, including pelvis and hip fractures.

Conclusions

Our findings suggest a modest but consistently higher increased risk of falls and fractures in PDP patients compared with PD patients without psychosis.

Hallucinations: diagnosis, neurobiology and clinical management

Hallucinations are important diagnostic symptoms in schizophrenia, but also occur in other medical and neuropsychiatric conditions. Not all patients with hallucinations are psychotic. There has been a surge of interest in the topic of hallucinations, as new research data have begun to reveal their neurobiology. Hallucinogenic molecules may also serve as new scaffolds for the development of new psychotropic drugs. We searched and reviewed recent literature, focusing on the refinement of clinical management, which was inspired by new data regarding the neurobiology of hallucination subtypes. We concluded that the successful management of hallucinations depends on accurate differential diagnosis to identify subtypes, which would then determine the most appropriate treatment.

Hippocampal Hyperactivity as a Druggable Circuit-Level Origin of Aberrant Salience in Schizophrenia

The development of current neuroleptics was largely aiming to decrease excessive dopaminergic signaling in the striatum. However, the notion that abnormal dopamine creates psychotic symptoms by causing an aberrant assignment of salience that drives maladaptive learning chronically during disease development suggests a therapeutic value of early interventions that correct salience-related neural processing. The mesolimbic dopaminergic output is modulated by several interconnected brain-wide circuits centrally involving the hippocampus and key relays like the ventral and associative striatum, ventral pallidum, amygdala, bed nucleus of the stria terminalis, nucleus reuniens, lateral and medial septum, prefrontal and cingulate cortex, among others. Unraveling the causal relationships between these circuits using modern neuroscience techniques holds promise for identifying novel cellular—and ultimately molecular—treatment targets for reducing transition to psychosis and symptoms of schizophrenia. Imaging studies in humans have implicated a hyperactivity of the hippocampus as a robust and early endophenotype in schizophrenia. Experiments in rodents, in turn, suggested that the activity of its output region—the ventral subiculum—may modulate dopamine release from ventral tegmental area (VTA) neurons in the ventral striatum. Even though these observations suggested a novel circuit-level target for anti-psychotic action, no therapy has yet been developed along this rationale. Recently evaluated treatment strategies—at least in part—target excess glutamatergic activity, e.g. N-acetyl-cysteine (NAC), levetiracetam, and mGluR2/3 modulators. We here review the evidence for the central implication of the hippocampus-VTA axis in schizophrenia-related pathology, discuss its symptom-related implications with a particular focus on aberrant assignment of salience, and evaluate some of its short-comings and prospects for drug discovery.

Hyper-serotonergic state determines onset and progression of idiopathic Parkinson's disease

Despite decades of research on Parkinson's disease (PD), the etiology of this disease remains unclear. The present manuscript introduces a new hypothesis proposing a hyper-serotonergic state as the main mechanism leading to axonal impairment both in dopaminergic and serotonergic neurons in PD. The strong serotonergic connection between the raphe nuclei and the dorsal raphe nuclei with the basal ganglia, all important brain structures associated with the pathophysiology of PD, emphasize a potential role for this neurotransmitter in PD. Importantly, a hyper-serotonergic state can lead to axonal growth impairment, an effect that seems to be selective to axons that can respond to this neurotransmitter. Serotonin seems to be a promising candidate to explain several of the poorly understood early symptoms of PD, including sleep impairment, anxiety, altered gastrointestinal motility and hallucinations. The hypothesis proposed here emphasizes that a hyper-serotonergic state would initially cause disruption of axonal transportation, an acute state in which axonal changes are reversible and the neurodegenerative process can be halted. As the hyper-serotonergic state persists, the accumulation of neurotoxic products and a sustained impairment in axonal transportation would lead to axonal death and culminate in an irreversible neurodegenerative process. The potential implications of this hypothesis are discussed, as well as how future research can be employed to further elucidate the role of serotonin on PD progression.

Aberrant resting-state oscillatory brain activity in Parkinson's disease patients with visual hallucinations: An MEG source-space study

To gain insight into possible underlying mechanism(s) of visual hallucinations (VH) in Parkinson's disease (PD), we explored changes in local oscillatory activity in different frequency bands with source-space magnetoencephalography (MEG). Eyes-closed resting-state MEG recordings were obtained from 20 PD patients with hallucinations (Hall+) and 20 PD patients without hallucinations (Hall-), matched for age, gender and disease severity. The Hall+ group was subdivided into 10 patients with VH only (unimodal Hall+) and 10 patients with multimodal hallucinations (multimodal Hall+). Subsequently, neuronal activity at source-level was reconstructed using an atlas-based beamforming approach resulting in source-space time series for 78 cortical and 12 subcortical regions of interest in the automated anatomical labeling (AAL) atlas. Peak frequency (PF) and relative power in six frequency bands (delta, theta, alpha1, alpha2, beta and gamma) were compared between Hall+ and Hall-, unimodal Hall+ and Hall-, multimodal Hall+ and Hall-, and unimodal Hall+ and multimodal Hall+ patients. PF and relative power per frequency band did not differ between Hall+ and Hall-, and multimodal Hall+ and Hall- patients. Compared to the Hall- group, unimodal Hall+ patients showed significantly higher relative power in the theta band (p = 0.005), and significantly lower relative power in the beta (p = 0.029) and gamma (p = 0.007) band, and lower PF (p = 0.011). Compared to the unimodal Hall+, multimodal Hall+ showed significantly higher PF (p = 0.007). In conclusion, a subset of PD patients with only VH showed slowing of MEG-based resting-state brain activity with an increase in theta activity, and a concomitant decrease in beta and gamma activity, which could indicate central cholinergic dysfunction as underlying mechanism of VH in PD. This signature was absent in PD patients with multimodal hallucinations.

Psychosis in neurodegenerative disorders: recent developments

PURPOSE OF REVIEW

This review presents the latest developments covered in the literature regarding psychosis in neurodegenerative disorders and discusses possible future research directions.

RECENT FINDINGS

Recent findings in the field of psychosis and neurodegenerative disorders revolve around four main themes. The first theme is the impact of sex on the expression of psychosis in neurodegenerative disorders. The second theme focuses on the relationship between psychosis and neurodegenerative disease biomarkers. The third concerns how psychotic symptoms in neurodegenerative disorders may share common mechanisms with other primary psychotic disorders such as schizophrenia. Finally, there have been some promising developments in the area of therapeutics to treat dementia-related psychosis involving both established and novel treatments.

SUMMARY

New findings in the field of neurodegeneration and psychosis parallel new directions in the field of neurodegeneration in general. More specifically, we have seen a shift in focus to issues highlighting the role of sex, biomarkers, translation to other disorders, and therapeutics.

Behavioral symptomatology and psychopharmacology of Lewy body dementia

Lewy body dementia (LBD) is an umbrella term for major neurocognitive disorders caused by Lewy body pathology. Parkinson's disease dementia (PDD) and Dementia with Lewy bodies (DLB) are the two main syndromes in LBD. LBDs typically present with cognitive impairment, cholinergic deficiency, neuropsychiatric symptoms such as visual hallucinations and paranoid delusions, as well as parkinsonian symptoms. Due to the urgency in diagnosing LBD early in the disease course to provide the most optimal management of these syndromes, it is important that clinicians elicit the most clinically significant symptoms during patient encounters. The focus of this chapter is to discuss current LBD classification systems and assessments, neuropathology of LBDs, behavioral symptomatology, contemporary management options, and possible future targets of treatment. PubMed was searched to obtain reviews and studies that pertain to classification, behavioral symptomatology, neurobiology, neuroimaging, and treatment of LBDs. Articles were chosen with a predilection to more recent clinical trials and systematic reviews or meta-analyses. Updates to diagnostic criteria have increased clinical diagnostic sensitivity and specificity. Current therapeutic modalities are limited as there is no current disease-modifying drug available. Cholinesterase inhibitors have been reported to be effective in decreasing neuropsychiatric and cognitive symptoms. Neuroleptics should be avoided unless clinically indicated. There is a paucity of studies investigating treatment options for mood symptoms. Current novel targets of treatment focus on decreasing α-synuclein burden. LBDs are a group of dementia syndromes that affect a significant portion of the elderly population. Early diagnosis and treatment is necessary to improve patient quality of life with current treatment options more focused on alleviating severe symptomatology rather than modifying disease pathology.

Psychotic disorders in late life: a narrative review

Psychotic disorders are not uncommon in late life. These disorders often have varied etiologies, different clinical presentations, and are associated with significant morbidity and mortality among the older adult population. Psychotic disorders in late life develop due to the complex interaction between various biological, psychological, social, and environmental factors. Given the significant morbidity and mortality associated with psychotic disorders in late life, a comprehensive work-up should be conducted when they are encountered. The assessment should not only identify the potential etiologies for the psychotic disorders, but also recognize factors that predicts possible outcomes for these disorders. Treatment approaches for psychotic disorders in late life should include a combination of nonpharmacological management strategies with the judicious use of psychotropic medications. When antipsychotic medications are necessary, they should be used cautiously with the goal of optimizing outcomes with regular monitoring of their efficacy and adverse effects.