Diagnosis and Treatment of Parkinson Disease: A Review

Role of the globus pallidus in motor and non-motor symptoms of Parkinson's disease

The globus pallidus plays a pivotal role in the basal ganglia circuit. Parkinson's disease is characterized by degeneration of dopamine-producing cells in the substantia nigra, which leads to dopamine deficiency in the brain that subsequently manifests as various motor and non-motor symptoms. This review aims to summarize the involvement of the globus pallidus in both motor and non-motor manifestations of Parkinson's disease. The firing activities of parvalbumin neurons in the medial globus pallidus, including both the firing rate and pattern, exhibit strong correlations with the bradykinesia and rigidity associated with Parkinson's disease. Increased beta oscillations, which are highly correlated with bradykinesia and rigidity, are regulated by the lateral globus pallidus. Furthermore, bradykinesia and rigidity are strongly linked to the loss of dopaminergic projections within the cortical-basal ganglia-thalamocortical loop. Resting tremors are attributed to the transmission of pathological signals from the basal ganglia through the motor cortex to the cerebellum-ventral intermediate nucleus circuit. The cortico-striato-pallidal loop is responsible for mediating pallidi-associated sleep disorders. Medication and deep brain stimulation are the primary therapeutic strategies addressing the globus pallidus in Parkinson's disease. Medication is the primary treatment for motor symptoms in the early stages of Parkinson's disease, while deep brain stimulation has been clinically proven to be effective in alleviating symptoms in patients with advanced Parkinson's disease, particularly for the movement disorders caused by levodopa. Deep brain stimulation targeting the globus pallidus internus can improve motor function in patients with tremor-dominant and non-tremor-dominant Parkinson's disease, while deep brain stimulation targeting the globus pallidus externus can alter the temporal pattern of neural activity throughout the basal ganglia-thalamus network. Therefore, the composition of the globus pallidus neurons, the neurotransmitters that act on them, their electrical activity, and the neural circuits they form can guide the search for new multi-target drugs to treat Parkinson's disease in clinical practice. Examining the potential intra-nuclear and neural circuit mechanisms of deep brain stimulation associated with the globus pallidus can facilitate the management of both motor and non-motor symptoms while minimizing the side effects caused by deep brain stimulation.

Role of copper in central nervous system physiology and pathology

Copper is a transition metal and an essential element for the organism, as alterations in its homeostasis leading to metal accumulation or deficiency have pathological effects in several organs, including the central nervous system. Central copper dysregulations have been evidenced in two genetic disorders characterized by mutations in the copper-ATPases ATP7A and ATP7B, Menkes disease and Wilson's disease, respectively, and also in multifactorial neurological disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. This review summarizes current knowledge about the role of copper in central nervous system physiology and pathology, reports about unbalances in copper levels and/or distribution under disease, describes relevant animal models for human disorders where copper metabolism genes are dysregulated, and discusses relevant therapeutic approaches modulating copper availability. Overall, alterations in copper metabolism may contribute to the etiology of central nervous system disorders and represent relevant therapeutic targets to restore tissue homeostasis.

Ribose-cysteine and levodopa abrogate Parkinsonism via the regulation of neurochemical and redox activities in alpha-synuclein transgenic Drosophila melanogaster models

Parkinson's disease (PD), the most prevalent type of parkinsonism, is a progressive neurodegenerative condition marked by several non-motor and motor symptoms. PD is thought to have a complex aetiology that includes a combination of age, genetic predisposition, and environmental factors. Increased expression of α-synuclein (α-Syn) protein is central to the evolvement of neuropathology in this devastating disorder, but the potential of ribose-cysteine and levodopa in abating pathophysiologic changes in PD model is unknown. Crosses were set up between flies conditionally expressing a pathological variant of human α-Syn (UAS-α-Syn) and those expressing GAL4 in neurons (elav-GAL4) to generate offspring referred to as PD flies. Flies were randomly assigned to five groups (n = 40) from the total population of flies, with each group having five replicates. Groups of PD flies were treated with either 500 mg/kg ribose-cysteine diet, 250 mg/kg levodopa diet, or a combination of the two compounds for 21 days, whereas the control group (w1118) and the PD group were exposed to a diet without ribose-cysteine or levodopa. In addition to various biochemical and neurochemical assays, longevity, larval motility, and gravitaxis assays were carried out. Locomotive capability, lifespan, fecundity, antioxidant state, and neurotransmitter systems were all significantly (p < 0.05) compromised by overexpression of α-Syn. However, flies treated both ribose cysteine and levodopa showed an overall marked improvement in motor functions, lifespan, fecundity, antioxidant status, and neurotransmitter system functions. In conclusion, ribose-cysteine and levodopa, both singly and in combination, potentiated a therapeutic effect on alpha-synuclein transgenic Drosophila melanogaster models of Parkinsonism.

Advanced Parkinson's disease treatment patterns in Italy: an observational study interim analysis

BACKGROUND

Oral levodopa remains the mainstay of treatment for Parkinson's disease (PD). However, as PD progresses, response to treatment may fluctuate. Managing fluctuations can be demanding for clinicians and patients. There is a paucity of real-world studies reporting on PD management in patients with fluctuations in treatment response, especially in patients with advanced stages of PD. The multicentre, observational Parkinson's Disease Fluctuations treatment PAthway (PD-FPA) study describes the real-life management of response fluctuations in Italian patients with advanced PD.

PATIENTS AND METHODS

PD-FPA had a retrospective and prospective phase; herein, retrospective results are presented. Ten Italian centres enrolled patients with a PD diagnosis from 10-15 years prior to study entry (T0) and who had ≥2-year history of fluctuations. Data on patient demographics, medical history, PD stage, fluctuation characteristics, symptoms, and prescribed treatments were collected at T0 and retrospectively (2 years prior to T0) via patient chart review/interview.

RESULTS

Overall, 296 patients (60% male, mean age 68 years, 84% with Hoehn and Yahr scores 2-3) were enrolled. At T0, most patients (99.3%) were on oral levodopa therapy. All patients used dopaminergic medications; adjunctive medications included dopamine agonists (56%) and monoamine oxidase B (60%) and catechol-O-methyltransferase enzyme inhibitors (41%). At T0, 51% of patients had changed therapy, with response fluctuations being the most common reason (74%); wearing-off was the most common fluctuation (83%).

CONCLUSION

This interim analysis of PD-FPA suggests that adequate levodopa dosing and adjunctive medications can stabilize advanced PD and provide patients with a good quality of life.

Optimization of Parkinson's disease therapy with plant extracts and nutrition's evolving roles

Parkinson's disease (PD) is a neurodegenerative disease characterized by death of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Death of dopaminergic cells in the SNpc leads to manifestations of motor dysfunction and non-motor symptoms of PD. The progression of PD symptoms severely affects the quality of life of patients and poses socio-economic problems to families and society at large. The clinical and neuropathological characteristics of PD are triggered by multiple factors such as oxidative stress, neuroinflammation, mitochondrial dysfunction, and protein aggregation. Notwithstanding the advancements in pharmacological therapy in PD management, there is burgeoning interest in alternative and complementary approaches, essentially nutrition and plant extracts strategies. This review gives widespread analysis of the role of nutrition and plant extracts in the management of PD. Studies that investigated the effects of various dietary compounds and plant extract on PD symptoms and progression were reviewed from existing literatures. Nutraceuticals, including vitamins and phytochemicals such as Mucuna pruriens have shown potential neuroprotective functions in preclinical and clinical studies. Indeed, these strategies ameliorate mitochondrial dysfunction, oxidative stress, and neuroinflammation, all which are implicated in the pathogenesis of PD. The neuroprotective mechanisms of nutrition and plant extracts in PD, with emphasis on their capacity to target multiple pathways implicated in PD are discussed. Additionally, challenges and limitations related with translating preclinical findings into clinical practice including standardization of dosing regimens, bioavailability, and inter-individual variability are discussed. Largely, this review elucidates on the role of nutrition and plant extracts as adjunctive therapy in PD management.

Repurposing ezetimibe as a neuroprotective agent in a rotenone-induced Parkinson's disease model in rats: Role of AMPK/SIRT-1/PGC-1α signaling and autophagy

As a severe neurological disorder, Parkinson's disease (PD) is distinguished by dopaminergic neuronal degeneration in the substantia nigra (SN), culminating in motor impairments. Several studies have shown that activation of the AMPK/SIRT1/PGC1α pathway contributes to an increase in mitochondrial biogenesis and is a promising candidate for the management of PD. Furthermore, turning on the AMPK/SIRT1/PGC1α pathway causes autophagy activation, which is fundamental for maintaining neuronal homeostasis. Interestingly, ezetimibe is an antihyperlipidemic agent that was recently reported to possess pleiotropic properties in neurology by triggering the phosphorylation and activation of AMPK. Thus, our study aimed to investigate the neuroprotective potential of ezetimibe in rats with rotenone-induced PD by activating AMPK. Adult male Wistar rats received rotenone (1.5 mg/kg, s.c.) every other day for 21 days to induce experimental PD. Rats were treated with ezetimibe (5 mg/kg/day, i.p.) 1 h before rotenone. Ezetimibe ameliorated the motor impairments in open field, rotarod and grip strength tests, restored striatal dopamine and tyrosine hydroxylase in the SN, up-regulated p-AMPK, SIRT1, and PGC1α striatal expression, upsurged the expression of ULK1, beclin1, and LC3II/I, reduced Bax/Bcl2 ratio, and alleviated rotenone-induced histopathological changes in striatum and SN. Our findings also verified the contribution of AMPK activation to the neuroprotective effect of ezetimibe by using the AMPK inhibitor dorsomorphin. Together, this work revealed that ezetimibe exerts a neuroprotective impact in rotenone-induced PD by activating AMPK/SIRT-1/PGC-1α signaling, enhancing autophagy, and attenuating apoptosis. Thus, ezetimibe's activation of AMPK could hold significant therapeutic promise for PD management.

Advances in animal models of Parkinson's disease

Parkinson's disease is a complex neurodegenerative disease characterized by progressive movement impairments. Predominant symptoms encompass resting tremor, bradykinesia, limb rigidity, and postural instability. In addition, it also includes a series of non-motor symptoms such as sleep disorders, hyposmia, gastrointestinal dysfunction, autonomic dysfunction and cognitive impairment. Pathologically, the disease manifests through dopaminergic neuronal loss and the presence of Lewy bodies. At present, no significant breakthrough has been achieved in clinical Parkinson's disease treatment. Exploring treatment modalities necessitate the establishment of scientifically sound animal models. In recent years, researchers have focused on replicating the symptoms of human Parkinson's disease, resulting in the establishment of various experimental animal models primarily through drugs and transgenic methods to mimic relevant pathologies and identify more effective treatments. This review examines traditional neurotoxin and transgenic animal models as well as α-synuclein pre-formed fibrils models, non-human primate models and non-mammalian specie models. Additionally, it introduces emerging models, including models based on optogenetics, induced pluripotent stem cells, and gene editing, aiming to provide a reference for the utilization of experimental animal models and clinical research for researchers in this field.

Association between kidney function and Parkinson's disease risk: a prospective study from the UK Biobank

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative influenced by various clinical factors. The potential relationship between renal function and the risk of PD remains poorly understood. This study aims to explore the association between kidney function and the risk of developing PD.

METHODS

A population-based cohort study was conducted using data from 400,571 UK Biobank participants. Renal function was assessed using the estimated glomerular filtration rate (eGFR), calculated from serum creatinine and cystatin C levels. The association between eGFR levels and PD risk was evaluated using univariate and multivariate Cox regression analyses, Restricted Cubic Spline (RCS) analysis, and Kaplan-Meier analysis. Additionally, a clinical prediction model was developed and its diagnostic accuracy was evaluated using ROC analysis. A heatmap was also constructed to examine the relationship between clinical factors and gray matter volume in various brain regions.

RESULTS

Over a median observation period of 13.8 years, 2740 PD events were recorded. Cox regression and Kaplan-Meier analyses revealed a significant association between decreased eGFR and increased PD risk, particularly in participants with eGFR < 30 ml/min/1.73 m2. This association was confirmed across three adjusted models. RCS analysis demonstrated a nonlinear relationship between decreasing eGFR and increasing PD risk. Furthermore, changes in eGFR were correlated with alterations in subcortical gray matter volume in regions such as the frontal cortex, striatum, and cerebellum. The clinical prediction model showed high diagnostic accuracy with AUC values of 0.776, 0.780, and 0.824 for 4-, 8-, and 16-year predictions, respectively.

CONCLUSION

Renal insufficiency is significantly associated with an increased risk of PD, highlighting the importance of maintaining good kidney function as a potential preventive measure against PD.

Human amniotic epithelial stem cell-derived dopaminergic neuron-like cells ameliorate motor dysfunction in a rat model of Parkinson's disease

AIMS

Parkinson's disease (PD) remains a substantial clinical challenge due to the progressive loss of midbrain dopaminergic (DA) neurons in nigrostriatal pathway. In this study, human amniotic epithelial stem cells (hAESCs)-derived dopaminergic neuron-like cells (hAESCs-DNLCs) were generated, with the aim of providing new therapeutic approach to PD.

MATERIALS AND METHODS

hAESCs, which were isolated from discarded placentas, were induced to differentiate into hAESCs-DNLCs by following a "two stages" induction protocol. The differentiation efficiency was assessed by quantitative real-time PCR (qRT-PCR), immunocytochemistry (ICC), and ELISA. Immunogenicity, cell viability and tumorigenicity of hAESCs-DNLC were analyzed before in vivo experiments. Subsequently, hAESCs-DNLCs were transplanted into PD rats, behavioral tests were monitored after graft, and the regeneration of DA neurons was detected by immunohistochemistry (IHC). Furthermore, to trace hAESCs-DNLCs in vivo, cells were pre-labeled with PKH67 green fluorescence.

KEY FINDINGS

hAESCs were positive for pluripotent markers and highly expressed neural stem cells (NSCs) markers. Based on this, we established an induction method reliably generates hAESCs-DNLCs, which was evidenced by epithelium-to-neuron morphological changes, elevated expressions of neuronal and DA neuronal markers, and increased secretion of dopamine. Moreover, hAESCs-DNLCs maintained high cell viability, no tumorigenicity and low immunogenicity, suggesting hAESCs-DNLCs an attractive implant for PD therapy. Transplantation of hAESCs-DNLCs into PD rats significantly ameliorated motor disorders, as well as enhanced the reinnervation of TH+ DA neurons in nigrostriatal pathway.

SIGNIFICANCE

Our study has demonstrated evident therapeutic effects of hAESCs-DNLCs, and provides a safe and promising solution for PD.

In vivo detection of endogenous toxic phenolic compounds of intestine

Phenol and p-cresol are two common toxic small molecules related to various diseases. Existing reports confirmed that high L-tyrosine in the daily diet can increase the concentration of phenolic compounds in blood and urine. L-tyrosine is a common component of protein-rich foods. Some anaerobic bacteria in the gut can convert non-toxic l-tyrosine into these two toxic phenolic compounds, phenol and p-cresol. Existing methods have been constructed for measuring the concentration of phenolic compound in feces. However, there is still a lack of direct visual evidence to measure the phenolic compounds in the intestine. In this study, we aimed to construct a whole-cell biosensor for phenolic compounds detection based on the dmpR, the regulator from the phenol metabolism cluster. The commensal bacterium Citrobacter amalonaticus PS01 was selected and used as the chassis. Compared with the biosensor based on ECN1917, the biosensor PS01[dmpR] could better implant into the mouse gut through gavage and showed a higher sensitive to phenolic compound. And the concentration of phenolic compounds in the intestines could be observed with the help of in vivo imaging system using PS01[dmpR]. This paper demonstrated endogenous phenol synthesis in the gut and the strategy of using commensal bacteria to construct whole-cell biosensors for detecting small molecule compounds in the intestines.

Dopamine Pathway and Parkinson's Risk Variants Are Associated with Levodopa-Induced Dyskinesia

BACKGROUND

Levodopa-induced dyskinesia (LID) is a common adverse effect of levodopa, one of the main therapeutics used to treat the motor symptoms of Parkinson's disease (PD). Previous evidence suggests a connection between LID and a disruption of the dopaminergic system as well as genes implicated in PD, including GBA1 and LRRK2.

OBJECTIVES

Our goal was to investigate the effects of genetic variants on risk and time to LID.

METHODS

We performed a genome-wide association study (GWAS) and analyses focused on GBA1 and LRRK2 variants. We also calculated polygenic risk scores (PRS) including risk variants for PD and variants in genes involved in the dopaminergic transmission pathway. To test the influence of genetics on LID risk we used logistic regression, and to examine its impact on time to LID we performed Cox regression including 1612 PD patients with and 3175 without LID.

RESULTS

We found that GBA1 variants were associated with LID risk (odds ratio [OR] = 1.65; 95% confidence interval [CI], 1.21-2.26; P = 0.0017) and LRRK2 variants with reduced time to LID onset (hazard ratio [HR] = 1.42; 95% CI, 1.09-1.84; P = 0.0098). The fourth quartile of the PD PRS was associated with increased LID risk (ORfourth_quartile = 1.27; 95% CI, 1.03-1.56; P = 0.0210). The third and fourth dopamine pathway PRS quartiles were associated with a reduced time to development of LID (HRthird_quartile = 1.38; 95% CI, 1.07-1.79; P = 0.0128; HRfourth_quartile = 1.38; 95% CI = 1.06-1.78; P = 0.0147).

CONCLUSIONS

This study suggests that variants implicated in PD and in the dopaminergic transmission pathway play a role in the risk/time to develop LID. Further studies will be necessary to examine how these findings can inform clinical care. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

l-theanine, the unique constituent of tea, improves neuronal survivability by curtailing inflammatory responses in MPTP model of Parkinson's disease

Discrete components of tea possess multitude of health advantages. Escalating evidence advocate a consequential association between habitual tea consumption and a subsided risk of Parkinson's disease (PD). l-theanine is a non-protein amino acid inherent in tea plants, which exhibits structural resemblance with glutamate, the copious excitatory neurotransmitter in brain. Neuromodulatory effects of l-theanine are evident from its competency in traversing the blood brain barrier, promoting a sense of calmness beyond enervation, and enhancing cognition and attention. Despite the multifarious reports on antioxidant properties of l-theanine and its potential to regulate brain neurotransmitter levels, it is obligatory to understand its exact contribution in ameliorating the pathophysiology of PD. In this study, MPTP-induced mouse model was established and PD-like symptoms were developed in test animals where an increasing dosage of l-theanine (5, 25, 50, 100 and 250 mg/kg) was intraperitoneally administered for 23 days. 50 and 100 mg/kg dosage of l-theanine alleviated motor impairment and specific non-motor symptoms in Parkinsonian mice. The dosage of 100 mg/kg of l-theanine also improved striatal dopamine and serotonin level and tyrosine-hydroxylase positive cell count in the substantia nigra. Most crucial finding of the study is the proficiency of l-theanine to diminish astroglial injury as well as nitric oxide synthesis, which suggests its possible credential to prevent neurodegeneration by virtue of its anti-inflammatory attribute.

Central Role of Hypothalamic Circuits for Acupuncture's Anti-Parkinsonian Effects

Despite clinical data stretching over millennia, the neurobiological basis of the effectiveness of acupuncture in treating diseases of the central nervous system has remained elusive. Here, using an established model of acupuncture treatment in Parkinson's disease (PD) model mice, we show that peripheral acupuncture stimulation activates hypothalamic melanin-concentrating hormone (MCH) neurons via nerve conduction. We further identify two separate neural pathways originating from anatomically and electrophysiologically distinct MCH neuronal subpopulations, projecting to the substantia nigra and hippocampus, respectively. Through chemogenetic manipulation specifically targeting these MCH projections, their respective roles in mediating the acupuncture-induced motor recovery and memory improvements following PD onset are demonstrated, as well as the underlying mechanisms mediating recovery from dopaminergic neurodegeneration, reactive gliosis, and impaired hippocampal synaptic plasticity. Collectively, these MCH neurons constitute not only a circuit-based explanation for the therapeutic effectiveness of traditional acupuncture, but also a potential cellular target for treating both motor and non-motor PD symptoms.

Regulatory Role and Molecular Mechanism of Mammalian Sterile 20-Like Kinase 1 in 1-Methyl-4-Phenylpyridinium Ion-Induced Parkinson's Disease Cell Model

Parkinson's disease (PD) is a multifactorial degenerative disease in the elder. Given the involvement of mammalian sterile 20-like kinase 1 (MST1) in PD, this article was to illustrate the mechanism of MST1 in 1-methyl-4-phenylpyridinium ion (MPP+)-induced PD cell model. Cells were treated with different concentrations of MPP+ to establish a PD cell model. Reverse transcription-quantitative polymerase chain reaction and Western blot revealed that MST1 expression and iron ion concentration increased, but cellular viability decreased with MPP+ concentration. Inhibition of MST1 decreased ferroptosis; increased cellular viability, iron ion content, and levels of glutathione peroxidase 4; and decreased reactive oxygen species and lactate dehydrogenase release. Upregulation of ferroptosis levels using ferroptosis agonist Erastin reduced the protective effect of MST1 inhibition on PD cells. Mechanistically, dual-luciferase analysis identified that miR-23b-3p targeted MST1 and inhibited its expression. Overexpression of miR-23b-3p inhibited MST1 levels, thereby reducing cellular ferroptosis and attenuating MPP+-induced cell injury. Collectively, MST1 expression increased with increasing MPP+ concentration, and miR-23b-3p targeted MST1 to reduce ferroptosis and MPP+-induced cell injury.

SIRT1 improves lactate homeostasis in the brain to alleviate parkinsonism via deacetylation and inhibition of PKM2

Sirtuin 1 (SIRT1) is a histone deacetylase and plays diverse functions in various physiological events, from development to lifespan regulation. Here, in Parkinson's disease (PD) model mice, we demonstrated that SIRT1 ameliorates parkinsonism, while SIRT1 knockdown further aggravates PD phenotypes. Mechanistically, SIRT1 interacts with and deacetylates pyruvate kinase M2 (PKM2) at K135 and K206, thus leading to reduced PKM2 enzyme activity and lactate production, which eventually results in decreased glial activation in the brain. Administration of lactate in the brain recapitulates PD-like phenotypes. Furthermore, increased expression of PKM2 worsens PD symptoms, and, on the contrary, inhibition of PKM2 by shikonin or PKM2-IN-1 alleviates parkinsonism in mice. Collectively, our data indicate that excessive lactate in the brain might be involved in the progression of PD. By improving lactate homeostasis, SIRT1, together with PKM2, are likely drug targets for developing agents for the treatment of neurodegeneration in PD.

Distinct Clinical Implications of Patient- Versus Clinician-Rated Motor Symptoms in Parkinson's Disease

BACKGROUND

Patient-rated motor symptoms (PRMS) and clinician-rated motor symptoms (CRMS) often differ in Parkinson's disease (PD).

OBJECTIVE

Our goal was to investigate the determinants and clinical implications of PRMS compared with CRMS in PD.

METHODS

This retrospective, observational cohort study analyzed the cross-sectional associations and longitudinal impacts of PRMS as assessed by the Movement Disorders Society-sponsored Unified PD Rating Scale (MDS-UPDRS) part 2, while controlling for CRMS measured by MDS-UPDRS part 3. Longitudinal analyses used Cox proportional hazards models and multiple linear mixed-effects random intercepts/slope models, adjusting for many clinical predictors. We conducted propensity score matching (PSM) to reinforce our analyses' robustness and surface-based morphometry to investigate neural correlates.

RESULTS

We enrolled 442 patients with early-stage PD. At baseline, regardless of CRMS, PRMS were associated with the severity of postural instability and gait disturbance (PIGD). Notably, PRMS independently and more accurately predicted faster long-term deterioration in motor function than CRMS (Hoehn and Yahr 4, adjusted hazard ratio per +1 point = 1.19 [95% confidence intervals, 1.08-1.32]), particularly in PIGD (PIGD subscore, β-interaction = 0.052 [95% confidence intervals, 0.018-0.086]). PSM confirmed these findings' robustness. Surface-based morphometry suggested that enhanced sensory processing was distinctively associated with PRMS.

CONCLUSIONS

In early-stage PD, PRMS weighed different aspects of symptoms and more effectively predicted motor deterioration compared to CRMS, with distinctive brain structural characteristics. The superior sensitivity of PRMS to subtle declines in drug-refractory symptoms like PIGD likely underlie our results, highlighting the importance of understanding the differential clinical implications of PRMS to prevent long-term motor deterioration. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Microstructural alterations in white matter and related neurobiology based on the new clinical subtypes of Parkinson's disease

Background and objectives

The advent of new clinical subtyping systems for Parkinson's disease (PD) has led to the classification of patients into distinct groups: mild motor predominant (PD-MMP), intermediate (PD-IM), and diffuse malignant (PD-DM). Our goal was to evaluate the efficacy of diffusion tensor imaging (DTI) in the early diagnosis, assessment of clinical progression, and prediction of prognosis of these PD subtypes. Additionally, we attempted to understand the pathological mechanisms behind white matter damage using single-photon emission computed tomography (SPECT) and cerebrospinal fluid (CSF) analyses.

Methods

We classified 135 de novo PD patients based on new clinical criteria and followed them up after 1 year, along with 45 healthy controls (HCs). We utilized tract-based spatial statistics to assess the microstructural changes of white matter at baseline and employed multiple linear regression to examine the associations between DTI metrics and clinical data at baseline and after follow-up.

Results

Compared to HCs, patients with the PD-DM subtype demonstrated reduced fractional anisotropy (FA), increased axial diffusivity (AD), and elevated radial diffusivity (RD) at baseline. The FA and RD values correlated with the severity of motor symptoms, with RD also linked to cognitive performance. Changes in FA over time were found to be in sync with changes in motor scores and global composite outcome measures. Furthermore, baseline AD values and their rate of change were related to alterations in semantic verbal fluency. We also discovered the relationship between FA values and the levels of α-synuclein and β-amyloid. Reduced dopamine transporter uptake in the left putamen correlated with RD values in superficial white matter, motor symptoms, and autonomic dysfunction at baseline as well as cognitive impairments after 1 year.

Conclusions

The PD-DM subtype is characterized by severe clinical symptoms and a faster progression when compared to the other subtypes. DTI, a well-established technique, facilitates the early identification of white matter damage, elucidates the pathophysiological mechanisms of disease progression, and predicts cognitively related outcomes. The results of SPECT and CSF analyses can be used to explain the specific pattern of white matter damage in patients with the PD-DM subtype.

Neuropathological findings and in vivo imaging correlates of the red nucleus compared to those of the substantia nigra pars compacta in parkinsonisms

INTRODUCTION

The substantia nigra pars compacta (SNc) is the key pathologic locus in neurodegenerative parkinsonian disorders. Recently, in vivo susceptibility MRI metrics were associated with postmortem glial cell density and tau burden in the SNc of parkinsonism subjects. This study investigated the red nucleus (RN), another iron-rich region adjacent to the SNc and a potential site of higher functionality in parkinsonisms.

METHODS

In vivo MRI and postmortem data were obtained from 34 parkinsonism subjects and 3 controls. Neuron density, glial cell density, and percentages of area occupied by α-synuclein and tau were quantified using digitized midbrain slides. R2* and quantitative susceptibility mapping (QSM) metrics in the RN and SNc were derived from multi-gradient echo images. Histopathology data were compared between the RN and SNc using paired t-tests. MRI-histology associations were analyzed using partial Pearson correlations.

RESULTS

The RN had greater neuron (t23 = 3.169, P = 0.004) and glial cell densities (t23 = 2.407, P = 0.025) than the SNc, whereas the SNc had greater α-synuclein (t28 = 4.614, P < 0.0001) and tau burden (t24 = 4.513, P = 0.0001). In both the RN (R2*: r = 0.47, P = 0.043; QSM: r = 0.52, P = 0.024) and SNc (R2*: r = 0.57, P = 0.01; QSM: r = 0.58, P = 0.009), MRI values were associated with glial cell density but not neuron density or α-synuclein (Ps > 0.092). QSM associated with tau burden (r = 0.49, P = 0.038) in the SNc, but not the RN.

CONCLUSIONS

The RN is resilient to parkinsonian-related pathological processes compared to the SNc, and susceptibility MRI captured glial cell density in both regions. These findings help to further our understanding of the underlying pathophysiological processes in parkinsonisms.

Prevalence of Thai patients with advanced Parkinson's disease and external validation of the 5-2-1 Criteria and the CDEPA Questionnaire: A single-centered, cross-sectional study

BACKGROUND

Advanced stage of Parkinson's disease (APD) diagnosis is challenging for general neurologists. The 5-2-1 Criteria and the Cuestionario De Enfermedad de Parkinson Avanzada (CDEPA) have been validated for screening for APD.

OBJECTIVE

This article reports the period-prevalence of APD defined by a movement disorder expert, the 5-2-1 Criteria, and CDEPA and to improve the screening performance of the 5-2-1 Criteria METHODS: A cross-sectional retrospective study at the Parkinson's disease (PD) clinic of a tertiary hospital in Bangkok, Thailand amongst all PD patients aged ≥ 18 years was performed from January 2016 to January 2020. We compared the characteristics of APD and non-APD patients. We externally validated the 5-2-1 Criteria and CDEPA. We explored improving the 5-2-1 Criteria.

RESULTS

Of 480 PD patients with complete data, the period-prevalence of APD by the movement disorder expert, the 5-2-1 Criteria and CDEPA were 37.1 %, 48.5 %, and 27.5 %, respectively. Adding requiring help with an activity of daily living and freezing of gait to the original 5-2-1 Criteria enhanced the sensitivity from 86.5 % (95 %CI 80.6, 91.2) to 94.9 % (95 %CI 90.6, 97.7) and negative predictive value (NPV) from 90.3 % (95 %CI 85.9, 93.7) to 96 % (95 %CI 92.6, 98.2). However, the CDEPA had a sensitivity of 62.9 % (95 %CI 55.4, 70) and NPV of 81.0 (95 %CI 76.5, 85).

CONCLUSION

The 5-2-1 Criteria had a good screening tool performance for general neurologists to refer APD patients for optimal treatments. The modified 5-2-1 Criteria had better performance than the original one. External validation is needed.

[Multidisciplinary Complex Treatment of Parkinson's disease : Cornerstone of an individualized treatment]

BACKGROUND

The inpatient Parkinson's disease multimodal complex treatment (PD-MCT) was applied more than 15,000 times in 2022, in Germany. This number is increasing as is Parkinson's disease (PD), which affects more than 400,000 people in Germany and leads to 100,000 disability-adjusted life years. In recent years, several observational studies have been conducted on the effectiveness of this kind of multidisciplinary care.

OBJECTIVE

To summarize and discuss the evidence on the nature, benefits and potential of PD-MCT.

METHODS

A narrative review of selected empirical findings was carried out.

RESULTS

The PD-MCT frequently lasts for 2-3 weeks and aims to maintain the quality of life of people with PD. Disease symptoms and activities of daily living are jointly improved by pharmacological strategies and activating therapies (physiotherapy, occupational therapy, speech and language therapy, physical training, art therapy). The PD-MCT is a useful measure to avoid or mitigate crisis situations in the course of the disease. A total of eight observational studies (n = 1246) have shown good effectiveness with a total mean improvement of the International Parkinson and Movement Disorder Society unified Parkinson's disease rating scale III (MDS-UPDRS III) by 7.8 points. The transfer of effects into everyday life through intensive and specialized community-based care must be ensured in order to achieve sustained effects on the quality of life. Ideally, this transfer can be supported by integrated PD networks and digital technologies in the future.

CONCLUSION

There is potential for development in the standardization, patient selection and quality assurance of PD-MCT as well as in the embedding in care structures such as PD networks. Open research questions include a precise definition of the target group and higher quality evidence of short-term and long-term effectiveness.

Computational study of associations between the synaptic conductance of STN and GPe and the development of Parkinson's disease

There is evidence that the subthalamic nucleus (STN) and globus pallidus pars externa (GPe) involve in the development of Parkinson's disease, a neurodegenerative disorder characterized by motor and non-motor symptoms and loss of dopaminergic neurons in which the error index (EI) in firing patterns is widely used to address the related issues. Whether and how this interaction mechanism of STN and GPe affects EI in Parkinson's disease is uncertain. To account for this, we propose a kind of basal ganglia-thalamic network model associated with Parkinson's disease coupled with neurons, and investigate the effect of synaptic conductance of STN and GPe on EI in this network, as well as their internal relationship under EI as an index. The results show a relationship like a piecewise function between the error index and the slope of the state transition function of synaptic conductance from STN to GPe ( g snge ) and from GPe to STN ( g gesn ). And there is an approximate negative correlation between EI and g gesn . Increasing g snge and decreasing g gesn can improve the fidelity of thalamus information transmission and alleviate Parkinson's disease effectively. These obtained results can give some theoretical evidence that the abnormal synaptic releases of STN and GPe may be the symptoms of the development of Parkinson's disease, and further enrich the understanding of the pathogenesis and treatment mechanism of Parkinson's disease.

Deep Learning for hand tracking in Parkinson's Disease video-based assessment: Current and future perspectives

BACKGROUND

Parkinson's Disease (PD) demands early diagnosis and frequent assessment of symptoms. In particular, analysing hand movements is pivotal to understand disease progression. Advancements in hand tracking using Deep Learning (DL) allow for the automatic and objective disease evaluation from video recordings of standardised motor tasks, which are the foundation of neurological examinations. In view of this scenario, this narrative review aims to describe the state of the art and the future perspective of DL frameworks for hand tracking in video-based PD assessment.

METHODS

A rigorous search of PubMed, Web of Science, IEEE Explorer, and Scopus until October 2023 using primary keywords such as parkinson, hand tracking, and deep learning was performed to select eligible by focusing on video-based PD assessment through DL-driven hand tracking frameworks RESULTS:: After accurate screening, 23 publications met the selection criteria. These studies used various solutions, from well-established pose estimation frameworks, like OpenPose and MediaPipe, to custom deep architectures designed to accurately track hand and finger movements and extract relevant disease features. Estimated hand tracking data were then used to differentiate PD patients from healthy individuals, characterise symptoms such as tremors and bradykinesia, or regress the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) by automatically assessing clinical tasks such as finger tapping, hand movements, and pronation-supination.

CONCLUSIONS

DL-driven hand tracking holds promise for PD assessment, offering precise, objective measurements for early diagnosis and monitoring, especially in a telemedicine scenario. However, to ensure clinical acceptance, standardisation and validation are crucial. Future research should prioritise large open datasets, rigorous validation on patients, and the investigation of new frontiers such as tracking hand-hand and hand-object interactions for daily-life tasks assessment.

Single-trial movement intention detection estimation in patients with Parkinson's disease: a movement-related cortical potential study

Objectives. Parkinson patients often suffer from motor impairments such as tremor and freezing of movement that can be difficult to treat. To unfreeze movement, it has been suggested to provide sensory stimuli. To avoid constant stimulation, episodes with freezing of movement needs to be detected which is a challenge. This can potentially be obtained using a brain-computer interface (BCI) based on movement-related cortical potentials (MRCPs) that are observed in association with the intention to move. The objective in this study was to detect MRCPs from single-trial EEG.Approach. Nine Parkinson patients executed 100 wrist movements and 100 ankle movements while continuous EEG and EMG were recorded. The experiment was repeated in two sessions on separate days. Using temporal, spectral and template matching features, a random forest (RF), linear discriminant analysis, and k-nearest neighbours (kNN) classifier were constructed in offline analysis to discriminate between epochs containing movement-related or idle brain activity to provide an estimation of the performance of a BCI. Three classification scenarios were tested: 1) within-session (using training and testing data from the same session and participant), between-session (using data from the same participant from session one for training and session two for testing), and across-participant (using data from all participants except one for training and testing on the remaining participant).Main results. The within-session classification scenario was associated with the highest classification accuracies which were in the range of 88%-89% with a similar performance across sessions. The performance dropped to 69%-75% and 70%-75% for the between-session and across-participant classification scenario, respectively. The highest classification accuracies were obtained for the RF and kNN classifiers.Significance. The results indicate that it is possible to detect movement intentions in individuals with Parkinson's disease such that they can operate a BCI which may control the delivery of sensory stimuli to unfreeze movement.

Treating activated regulatory T cells with pramipexole protects human dopaminergic neurons from 6-OHDA-induced degeneration

BACKGROUND

Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra, which promotes a sustained inflammatory environment in the central nervous system. Regulatory T cells (Tregs) play an important role in the control of inflammation and might play a neuroprotective role. Indeed, a decrease in Treg number and function has been reported in PD. In this context, pramipexole, a dopaminergic receptor agonist used to treat PD symptoms, has been shown to increase peripheral levels of Treg cells and improve their suppressive function. The aim of this work was to determine the effect of pramipexole on immunoregulatory Treg cells and its possible neuroprotective effect on human dopaminergic neurons differentiated from human embryonic stem cells.

METHODS

Treg cells were sorted from white blood cells of healthy human donors. Assays were performed with CD3/CD28-activated and non-activated Treg cells treated with pramipexole at concentrations of 2 or 200 ng/mL. These regulatory cells were co-cultured with in vitro-differentiated human dopaminergic neurons in a cytotoxicity assay with 6-hydroxydopamine (6-OHDA). The role of interleukin-10 (IL-10) was investigated by co-culturing activated IL-10-producing Treg cells with neurons. To further investigate the effect of treatment on Tregs, gene expression in pramipexole-treated, CD3/CD28-activated Treg cells was determined by Fluidigm analysis.

RESULTS

Pramipexole-treated CD3/CD28-activated Treg cells showed significant protective effects on dopaminergic neurons when challenged with 6-OHDA. Pramipexole-treated activated Treg cells showed neuroprotective capacity through mechanisms involving IL-10 release and the activation of genes associated with regulation and neuroprotection.

CONCLUSION

Anti-CD3/CD28-activated Treg cells protect dopaminergic neurons against 6-OHDA-induced damage. In addition, activated, IL-10-producing, pramipexole-treated Tregs also induced a neuroprotective effect, and the supernatants of these co-cultures promoted axonal growth. Pramipexole-treated, activated Tregs altered their gene expression in a concentration-dependent manner, and enhanced TGFβ-related dopamine receptor regulation and immune-related pathways. These findings open new perspectives for the development of immunomodulatory therapies for the treatment of PD.

Cost-Effectiveness Analysis of COMT-Inhibitors as Adjuvant Treatments to Levodopa in Patients with Advanced Parkinson's Disease

PURPOSE

We aimed to elicit scientific evidence on the cost-effectiveness of two catechol-O-methyltransferase inhibitors (COMT-i) versus no COMT-i in patients with advanced Parkinson's disease.

METHODS

A mixed model of the decision tree and a Markov model with three health states by OFF-time level (<25%, ≥25%, and death) was constructed to compare opicapone (OPC), entacapone (ENT), and no COMT-i over a lifetime. A hypothetical cohort of 10,000 patients was created and simulated based on the characteristics of the BIPARK trial subjects.

FINDINGS

Two COMT-i (OPC and ENT) were identified as a cost-effective option compared to no COMT-i. Probabilistic sensitivity analysis showed that over 90% of the simulations proved the robust cost-effectiveness of COMT-i. When the time horizon as the most influential factor decreases to a 5- and 10-year period, COMT-i can be a cost-saving option. Although ENT may be the preferred option over OPC economically because of its lower price, OPC can be acceptable if the drug price is reduced by 17%.

IMPLICATIONS

Add-on treatment with COMT-i in patients with PD receiving levodopa/carbidopa appears to be cost-saving compared with not using COMT-i. In the future, it is necessary to evaluate the economic evaluation of COMT-i based on long-term real-world evidence.

Proteogenomic network analysis reveals dysregulated mechanisms and potential mediators in Parkinson's disease

Parkinson's disease is highly heterogeneous across disease symptoms, clinical manifestations and progression trajectories, hampering the identification of therapeutic targets. Despite knowledge gleaned from genetics analysis, dysregulated proteome mechanisms stemming from genetic aberrations remain underexplored. In this study, we develop a three-phase system-level proteogenomic analytical framework to characterize disease-associated proteins and dysregulated mechanisms. Proteogenomic analysis identified 577 proteins that enrich for Parkinson's disease-related pathways, such as cytokine receptor interactions and lysosomal function. Converging lines of evidence identified nine proteins, including LGALS3, CSNK2A1, SMPD3, STX4, APOA2, PAFAH1B3, LDLR, HSPB1, BRK1, with potential roles in disease pathogenesis. This study leverages the largest population-scale proteomics dataset, the UK Biobank Pharma Proteomics Project, to characterize genetically-driven protein disturbances associated with Parkinson's disease. Taken together, our work contributes to better understanding of genome-proteome dynamics in Parkinson's disease and sets a paradigm to identify potential indirect mediators connected to GWAS signals for complex neurodegenerative disorders.

Potential application of aptamers combined with DNA nanoflowers in neurodegenerative diseases

The efficacy of neurotherapeutic drugs hinges on their ability to traverse the blood-brain barrier and access the brain, which is crucial for treating or alleviating neurodegenerative diseases (NDs). Given the absence of definitive cures for NDs, early diagnosis and intervention become paramount in impeding disease progression. However, conventional therapeutic drugs and existing diagnostic approaches must meet clinical demands. Consequently, there is a pressing need to advance drug delivery systems and early diagnostic methods tailored for NDs. Certain aptamers endowed with specific functionalities find widespread utility in the targeted therapy and diagnosis of NDs. DNA nanoflowers (DNFs), distinctive flower-shaped DNA nanomaterials, are intricately self-assembled through rolling ring amplification (RCA) of circular DNA templates. Notably, imbuing DNFs with diverse functionalities becomes seamlessly achievable by integrating aptamer sequences with specific functions into RCA templates, resulting in a novel nanomaterial, aptamer-bound DNFs (ADNFs) that amalgamates the advantageous features of both components. This article delves into the characteristics and applications of aptamers and DNFs, exploring the potential or application of ADNFs in drug-targeted delivery, direct treatment, early diagnosis, etc. The objective is to offer prospective ideas for the clinical treatment or diagnosis of NDs, thereby contributing to the ongoing efforts in this critical field.

Digital Intervention Promoting Physical Activity in People Newly Diagnosed with Parkinson's Disease: Feasibility and Acceptability of the Knowledge, Exercise-Efficacy and Participation (KEEP) Intervention

Background

Exercise promotion interventions for people with Parkinson's disease (PD) are often offered on a face-to-face basis, follow a generic "one-size-fit-all" approach, and are not typically delivered at diagnosis. Considering PD's heterogenous nature, the existing evidence on the merits of exercise on symptom management and the expressed wishes of people living with PD for access to timely and tailored evidence-based information, there is a demand for interventions that are easily accessible, scalable and co-designed with people living with PD.

Objective

Evaluate the feasibility and acceptability of a co-designed digital intervention promoting exercise and physical activity, in people newly diagnosed with PD.

Methods

Thirty people living with PD for less than one year participated in an assessor-blinded randomized feasibility trial from June 2022 to April 2023. The intervention group received the 8-week Knowledge, Exercise Efficacy and Participation (KEEP) intervention comprising 6 interactive digital modules and 4 online live group discussions facilitated by a specialist physiotherapist. Assessments were performed at baseline, post intervention and at 6-month follow up.

Results

Thirty participants were recruited to target with a 64% recruitment rate (30/47). All but one participant completed the 6-month follow-up assessment. There was high retention (97%), module completion (91%), and online discussion attendance (88%). Outcome measure collection was feasible, including accelerometer data with a daily average wear time of 23.9 hours (SD:0.295).

Conclusions

The KEEP intervention was feasible and acceptable in people newly diagnosed with PD. A larger trial is needed to assess intervention efficacy and correlation between knowledge, self-efficacy, and activity levels.

Exploring circular RNAs as biomarkers for Parkinson's disease and their expression changes after aerobic exercise rehabilitation

Circular RNAs (circRNAs) are circularized single-stranded ribonucleic acids that interacts with DNA, RNA, and proteins to play critical roles in cell biology. CircRNAs regulate microRNA content, gene expression, and may code for specific peptides. Indeed, circRNAs are differentially expressed in neurodegenerative disorders like Parkinson's disease (PD), playing a potential role in the mechanisms of brain pathology. The RNA molecules with aberrant expression in the brain can cross the blood-brain barrier and reach the bloodstream, which enable their use as non-invasive PD disease biomarker. Promising targets with valuable discriminatory ability in combined circRNA signatures include MAPK9_circ_0001566, SLAIN1_circ_0000497, SLAIN2_circ_0126525, PSEN1_circ_0003848, circ_0004381, and circ_0017204. On the other hand, regular exercises are effective therapy for mitigating PD symptoms, promoting neuroprotective effects with epigenetic modulation. Aerobic exercises slow symptom progression in PD by improving motor control, ameliorating higher functions, and enhancing brain activity and neuropathology. These improvements are accompanied by changes circRNA expression, including hsa_circ_0001535 (circFAM13B) and hsa_circ_0000437 (circCORO1C). The sensitivity of current methods for detecting circulating circRNAs is considered a limitation. While amplification kits already exist for low-abundant microRNAs, similar kits are needed for circRNAs. Alternatively, the use of digital PCR can help overcome this constraint. The current review examines the potential use of circRNAs as non-invasive biomarkers of PD and to assess the effects of rehabilitation. Although circRNAs hold promise as targets for PD diagnosis and therapeutics, further validation is needed before their clinical implementation.

The Impact of the Dietary Intake of Vitamin B12, Folic Acid, and Vitamin D3 on Homocysteine Levels and the Health-Related Quality of Life of Levodopa-Treated Patients with Parkinson's Disease-A Pilot Study in Romania

BACKGROUND AND OBJECTIVES

Previous studies have shown that the levodopa treatment of Parkinson's disease (PD) elevates circulating homocysteine levels, which are associated with an increased risk of cardiovascular and neurological disorders, or thrombosis. The present trial aimed to examine whether the intake of vitamin B12, folic acid, and vitamin D3 supplements improved homocysteine level and quality of life (QoL).

MATERIALS AND METHODS

An interventional prospective trial was conducted in multiple centers across Romania. Participants with clinically established PD taking at least 300 mg/day of levodopa for more than 1 year received a daily tablet of a supplement containing 800 UI of vitamin D3, 1000 µg of folic acid, and 15 µg of vitamin B12. They were followed for 6 months and their serum homocysteine, vitamin B12, vitamin D, and QoL scores were measured at baseline and at 6 months of treatment. QoL was measured using a 15D questionnaire, which assesses mobility, vision, hearing, breathing, sleeping, eating, speech, excretion, usual activities, mental function, discomfort and symptoms, depression, distress, vitality, and sexual activity.

RESULTS

Twenty-four PD patients with a mean age of 71 ± 5.04 years (54.2% male and 45.8% female) finished the study. After the intervention, the mean score of speech, mental function, discomfort and symptoms, depression, and QoL significantly increased (p < 0.05 for all). Also, the serum homocysteine and vitamin D were significantly enhanced (p < 0.0001 and p = 0.025, respectively). Changes in vitamin B12 were not statistically significant at 6 months of treatment (p = 0.996). No gender differences were found among the changes that we have demonstrated for homocysteine, vitamin B12, vitamin D, and QoL levels (p < 0.05 for all).

CONCLUSIONS

The findings of this study showed that the dietary intake of vitamin B12, folic acid, and vitamin D3 remarkably decreased the dimensions of homocysteine and finally increased the total score of QoL in PD patients. We have successfully captured the potential benefits of the supplementation regimen over time and provided insights into the broader implications for managing PD with a focus on nutritional support.

Potential Neuroprotective Effect of the Endocannabinoid System on Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by alterations in motor capacity resulting from a decrease in the neurotransmitter dopamine due to the selective death of dopaminergic neurons of the nigrostriatal pathway. Unfortunately, conventional pharmacological treatments fail to halt disease progression; therefore, new therapeutic strategies are needed, and currently, some are being investigated. The endocannabinoid system (ECS), highly expressed in the basal ganglia (BG) circuit, undergoes alterations in response to dopaminergic depletion, potentially contributing to motor symptoms and the etiopathogenesis of PD. Substantial evidence supports the neuroprotective role of the ECS through various mechanisms, including anti-inflammatory, antioxidative, and antiapoptotic effects. Therefore, the ECS emerges as a promising target for PD treatment. This review provides a comprehensive summary of current clinical and preclinical evidence concerning ECS alterations in PD, along with potential pharmacological targets that may exert the protection of dopaminergic neurons.

Can exercise benefits be harnessed with drugs? A new way to combat neurodegenerative diseases by boosting neurogenesis

Adult hippocampal neurogenesis (AHN) is affected by multiple factors, such as enriched environment, exercise, ageing, and neurodegenerative disorders. Neurodegenerative disorders can impair AHN, leading to progressive neuronal loss and cognitive decline. Compelling evidence suggests that individuals engaged in regular exercise exhibit higher production of proteins that are essential for AHN and memory. Interestingly, specific molecules that mediate the effects of exercise have shown effectiveness in promoting AHN and cognition in different transgenic animal models. Despite these advancements, the precise mechanisms by which exercise mimetics induce AHN remain partially understood. Recently, some novel exercise molecules have been tested and the underlying mechanisms have been proposed, involving intercommunications between multiple organs such as muscle-brain crosstalk, liver-brain crosstalk, and gut-brain crosstalk. In this review, we will discuss the current evidence regarding the effects and potential mechanisms of exercise mimetics on AHN and cognition in various neurological disorders. Opportunities, challenges, and future directions in this research field are also discussed.

Tapered cross-linked ZnO nanowire bundle arrays on three-dimensional graphene foam for highly sensitive electrochemical detection of levodopa

It is crucial to accurately and rapidly monitor the levodopa (LD) concentration for accurate classification and treatment of dyskinesia in Parkinson's disease. In this paper, 3D graphene foam (GF) with a highly conductive network is obtained by chemical vapor deposition. 3D GF serves as the substrate for hydrothermal in situ growth of tapered cross-linked ZnO nanowire bundle arrays (ZnO NWBAs), enabling the development of a highly sensitive detection platform for LD. The formation mechanism of a tapered cross-linked ZnO nanowire bundle arrays on 3D GF is put forward. The integration of 3D GF and ZnO NWBAs can accelerate the electron transfer rate and increase the contact area with biomolecules, resulting in high electrochemical properties. The electrode composed of ZnO NWBAs on 3D GF exhibits significant sensitivity (1.66 µA·µM-1·cm-2) for LD detection in the concentration range 0-60 µM. The electrode is able to rapidly and specifically determine LD in mixed AA or UA solution. The selectivity mechanism of the electrode is also explained by the bandgap model. Furthermore, the successful detection of LD in serum demonstrates the practicality of the electrode and its great potential for clinical application.

Deep brain stimulation of the subthalamic nucleus under general anesthesia versus local anesthesia in the treatment of Parkinson's disease: a meta-analysis of randomized clinical trials

Deep brain stimulation (DBS) stands as the preferred treatment for Parkinson's disease (PD) patients manifesting refractory motor symptoms or when medication side effects outweigh the benefits. Though traditionally administered under local anesthesia coupled with sedation (LA + S), recent evidence hints at comparable outcomes under general anesthesia (GA). This systematic review and meta-analysis aimed to scrutinize post-surgical outcomes in randomized PD patients undergoing DBS surgery while GA versus LA + S. We searched PubMed, Cochrane, and Embase databases following PRISMA guidelines. We included randomized studies directly comparing DBS surgery under GA versus LA + S, delineating clinical outcomes. Safety outcomes assessed disparities in infection and hemorrhage risk. Mean differences (MD) and Risk Differences (RD) with 95% Confidence Intervals (CI) were utilized to evaluate outcomes, under a random-effects model. Heterogeneity was evaluated through I² statistics, and in studies exhibiting high heterogeneity, exclusion analysis was performed. Evaluated outcomes encompassed motor improvement, complications, behavioral and mood effects gauged by the Unified Parkinson's Disease Rating Scale (UPDRS), Parkinson's Disease Questionnaire 39 (PDQ39), and daily levodopa equivalent dose (LEDD). A total of 3 studies, encompassing 203 patients, were reviewed. At a 6-month follow-up, in patients undergoing GA during surgery, there was no statistically significant difference compared to the LA + S group in terms of UPDRS III ON (MD 0.19; 95% CI -2.21 to 2.59; p = 0.88; I²=0%), UPDRS III OFF (MD 0.58; 95% CI -4.30 to 5.45; p = 0.21; I²=0%), UPDRS IV ON ( (MD 0.98; 95% CI -0.95 to 2.92; p = 0.32; I²=23%), PDQ39 (MD -1.27; 95% CI -6.31 to 3.77; p = 0.62; I²=0%), and LEDD (MD -1.99; 95% CI -77.88 to 73.90; p = 0.96; I²=32%). There was no statistically significant difference between groups in terms of infection (RD 0.02; 95% CI -0.02 to 0.05; p = 0.377; I²=0%) or hemorrhage (RD 0.04; 95% CI -0.03 to 0.11; p = 0.215; I²=0%). Our findings suggest, based on short-term follow-up, that GA is not inferior to LA + S in terms of benefits for the selected outcomes. However, further studies are needed to determine whether there are significant long-term clinical differences between these groups.

Investigating the molecular mechanisms underlying the co-occurrence of Parkinson's disease and inflammatory bowel disease through the integration of multiple datasets

Parkinson's disease (PD) and inflammatory bowel disease (IBD) are chronic diseases affecting the central nervous system and gastrointestinal tract, respectively. Recent research suggests a bidirectional relationship between neurodegeneration in PD and intestinal inflammation in IBD. PD patients may experience gastrointestinal dysfunction over a decade before motor symptom onset, and IBD may increase the risk of developing PD. Despite the "gut-brain axis" concept, the underlying pathophysiological mechanisms of this potential association remain unclear. This study aimed to investigate the biological mechanisms of differentially expressed genes in PD and IBD using bioinformatics tools, providing novel insights into the co-diagnosis and treatment of these diseases. We constructed a gene marker for disease diagnosis and identified five important genes (BTK, NCF2, CRH, FCGR3A and SERPINA3). Through nomogram and decision tree analyses, we found that both the IBD and PD required only the expression levels of BTK and NCF2 for accurate discrimination. Additionally, small molecule drugs RO-90-7501 and MST-312 may be useful for the treatment of both IBD and PD. These findings offer new perspectives on the co-diagnosis and treatment of PD and IBD, and suggest that targeting BTK may be a promising therapeutic strategy for both diseases.

Parkinson's disease psychosis associated with accelerated multidomain cognitive decline

BACKGROUND

Cognitive deficits are associated with poor quality of life and increased risk of development of dementia in patients with Parkinson's disease (PD) psychosis. The trajectory of cognitive decline in PD psychosis remains however unclear.

OBJECTIVE

We examined this using data from the Parkinson's Progression Markers Initiative study.

METHODS

We analysed data from patients with drug-naïve PD (n=676) and healthy controls (HC, n=187) over 5 years, and examined all cognitive measures assessed at each time point. We classified patients with PD into those who developed psychosis over the course of the study (PDP) and those without psychosis throughout (PDnP) using the Movement Disorders Society Unified Parkinson's Disease Rating Scale part I hallucinations/psychosis item. We used linear mixed-effect models with restricted maximum likelihood. Age, sex, ethnicity, education and neuropsychiatric and PD-specific symptoms were entered as covariates of interest.

FINDINGS

There were no baseline cognitive differences between PD patient groups. There were differences in cognitive performance between PD and HC across the majority of the assessments.Patients with PDP exhibited greater cognitive decline over 5 years compared with PDnP across most domains even after controlling for sociodemographics, depression, sleepiness, rapid eye movement sleep behaviour disorder and motor symptom severity (immediate recall, b=-0.288, p=0.003; delayed recall, b=-0.146, p=0.003; global cognition, Montreal Cognitive Assessment, b=-0.206, p<0.001; visuospatial, b=-0.178, p=0.012; semantic fluency, b=-0.704, p=0.002; processing speed, b=-0.337, p=0.029).

CONCLUSIONS

Patients with PD psychosis exhibited decline in semantic aspects of language, processing speed, global cognition, visuospatial abilities and memory, regardless of sociodemographic characteristics, neuropsychiatric and motor symptoms. These cognitive domains, particularly semantic aspects of language may therefore play an important role in PD psychosis and warrant further investigation.

TRIAL REGISTRATION NUMBER

NCT01141023.

Risk Factors for Postoperative Delirium Severity After Deep Brain Stimulation Surgery in Parkinson's Disease

Background

Postoperative delirium (POD) is a serious complication following deep brain stimulation (DBS) but only received little attention. Its main risk factors are higher age and preoperative cognitive deficits. These are also main risk factors for long-term cognitive decline after DBS in Parkinson's disease (PD).

Objective

To identify risk factors for POD severity after DBS surgery in PD.

Methods

57 patients underwent DBS (21 female; age 60.2±8.2; disease duration 10.5±5.9 years). Preoperatively, general, PD- and surgery-specific predictors were recorded. Montreal Cognitive Assessment and the neuropsychological test battery CANTAB ConnectTM were used to test domain-specific cognition. Volumes of the cholinergic basal forebrain were calculated with voxel-based morphometry. POD severity was recorded with the delirium scales Confusion Assessment Method for Intensive Care Unit (CAM-ICU) and Nursing Delirium Scale (NU-DESC). Spearman correlations were calculated for univariate analysis of predictors and POD severity and linear regression with elastic net regularization and leave-one-out cross-validation was performed to fit a multivariable model.

Results

21 patients (36.8%) showed mainly mild courses of POD following DBS. Correlation between predicted and true POD severity was significant (spearman rho = 0.365, p = 0.001). Influential predictors were age (p < 0.001), deficits in attention and motor speed (p = 0.002), visual learning (p = 0.036) as well as working memory (p < 0.001), Nucleus basalis of Meynert volumes (p = 0.003) and burst suppression (p = 0.005).

Conclusions

General but also PD- and surgery-specific factors were predictive of POD severity. These findings underline the multifaceted etiology of POD after DBS in PD. Valid predictive models must therefore consider general, PD- and surgery-specific factors.

Exacerbation of delirium and epileptic seizures in an older man with idiopathic Parkinson's disease due to multiple prescriptions: a case report

Introduction

Parkinson's disease (PD) is a disorder characterized by motor symptoms, such as rigidity, akinesia, and resting tremor, as well as non-motor symptoms, including psychiatric manifestations and autonomic failure. The prevalence of PD increases with age, and the condition is more common in men than in women. Conversely, polypharmacy has emerged as a paramount medical concern, especially among older patients, correlating with medicines' adverse effects, interactions between medicines, frequent admissions to the hospital, and a high risk of morbidity and mortality.

Case description

We encountered an older male patient with idiopathic PD and mild renal dysfunction. Originally prescribed 14 types of medicines, including anti-PD drugs, the patient developed delirium and epileptic seizures during hospitalization. After reducing the number of medications, including amantadine, the symptoms significantly improved. This clinical course suggests that polypharmacy, in addition to PD itself, poses a significant risk of delirium and epileptic seizures, even in patients with mild renal dysfunction.

Conclusion

This report is indicative of the risk of polypharmacy and highlights the importance of citing drug interactions for a correct diagnosis in patients presenting with complex symptoms.

Delivery of CDNF by AAV-mediated gene transfer protects dopamine neurons and regulates ER stress and inflammation in an acute MPTP mouse model of Parkinson's disease

Cerebral dopamine neurotrophic factor (CDNF) and its close structural relative, mesencephalic astrocyte-derived neurotrophic factor (MANF), are proteins with neurotrophic properties. CDNF protects and restores the function of dopamine (DA) neurons in rodent and non-human primate (NHP) toxin models of Parkinson's disease (PD) and therefore shows promise as a drug candidate for disease-modifying treatment of PD. Moreover, CDNF was found to be safe and to have some therapeutic effects on PD patients in phase 1/2 clinical trials. However, the mechanism underlying the neurotrophic activity of CDNF is unknown. In this study, we delivered human CDNF (hCDNF) to the brain using an adeno-associated viral (AAV) vector and demonstrated the neurotrophic effect of AAV-hCDNF in an acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. AAV-hCDNF resulted in the expression of hCDNF in the striatum (STR) and substantia nigra (SN), and no toxic effects on the nigrostriatal pathway were observed. Intrastriatal injection of AAV-hCDNF reduced motor impairment and partially alleviated gait dysfunction in the acute MPTP mouse model. In addition, gene therapy with AAV-hCDNF had significant neuroprotective effects on the nigrostriatal pathway and decreased the levels of interleukin 1beta (IL-1β) and complement 3 (C3) in glial cells in the acute MPTP mouse model. Moreover, AAV-hCDNF reduced C/EBP homologous protein (CHOP) and glucose regulatory protein 78 (GRP78) expression in astroglia. These results suggest that the neuroprotective effects of CDNF may be mediated at least in part through the regulation of neuroinflammation and the UPR pathway in a mouse MPTP model of PD in vivo.

Grasping the big picture: impact analysis of screening tools for timely referral for device-aided therapies

Several screening tools are available to assist general neurologists in the timely identification of patients with advanced Parkinson's disease (PD) who may be eligible for referral for a device-aided therapy (DAT). However, it should be noted that not all of these clinical decision rules have been developed and validated in a thorough and consistent manner. Furthermore, only a limited number of head-to-head comparisons have been performed. Available studies suggest that D-DATS has a higher positive predictive value and higher specificity than the 5-2-1 criteria, while the sensitivity of both screening tools is similar. However, unanswered questions remain regarding the validity of the decision rules, such as whether the diagnostic performance measures from validation studies are generalizable to other populations. Ultimately, the question is whether a screening tool will effectively and efficiently improve the quality of life of patients with PD. To address this key question, an impact analysis should be performed. The authors intend to set up a multinational cluster randomised controlled trial to compare the D-DATS and 5-2-1 criteria on the downstream consequences of implementing these screening tools, with a particular focus on the impact on disability and quality of life.

The Role of Non-Invasive Brain Modulation in Identifying Disease Biomarkers for Diagnostic and Therapeutic Purposes in Parkinsonism

Over the past three decades, substantial advancements have occurred in non-invasive brain stimulation (NIBS). These developments encompass various non-invasive techniques aimed at modulating brain function. Among the most widely utilized methods today are transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES), which include direct- or alternating-current transcranial stimulation (tDCS/tACS). In addition to these established techniques, newer modalities have emerged, broadening the scope of non-invasive neuromodulation approaches available for research and clinical applications in movement disorders, particularly for Parkinson's disease (PD) and, to a lesser extent, atypical Parkinsonism (AP). All NIBS techniques offer the opportunity to explore a wide range of neurophysiological mechanisms and exert influence over distinct brain regions implicated in the pathophysiology of Parkinsonism. This paper's first aim is to provide a brief overview of the historical background and underlying physiological principles of primary NIBS techniques, focusing on their translational relevance. It aims to shed light on the potential identification of biomarkers for diagnostic and therapeutic purposes, by summarising available experimental data on individuals with Parkinsonism. To date, despite promising findings indicating the potential utility of NIBS techniques in Parkinsonism, their integration into clinical routine for diagnostic or therapeutic protocols remains a subject of ongoing investigation and scientific debate. In this context, this paper addresses current unsolved issues and methodological challenges concerning the use of NIBS, focusing on the importance of future research endeavours for maximizing the efficacy and relevance of NIBS strategies for individuals with Parkinsonism.

Speech's syllabic rhythm and articulatory features produced under different auditory feedback conditions identify Parkinsonism

Diagnostic tests for Parkinsonism based on speech samples have shown promising results. Although abnormal auditory feedback integration during speech production and impaired rhythmic organization of speech are known in Parkinsonism, these aspects have not been incorporated into diagnostic tests. This study aimed to identify Parkinsonism using a novel speech behavioral test that involved rhythmically repeating syllables under different auditory feedback conditions. The study included 30 individuals with Parkinson's disease (PD) and 30 healthy subjects. Participants were asked to rhythmically repeat the PA-TA-KA syllable sequence, both whispering and speaking aloud under various listening conditions. The results showed that individuals with PD had difficulties in whispering and articulating under altered auditory feedback conditions, exhibited delayed speech onset, and demonstrated inconsistent rhythmic structure across trials compared to controls. These parameters were then fed into a supervised machine-learning algorithm to differentiate between the two groups. The algorithm achieved an accuracy of 85.4%, a sensitivity of 86.5%, and a specificity of 84.3%. This pilot study highlights the potential of the proposed behavioral paradigm as an objective and accessible (both in cost and time) test for identifying individuals with Parkinson's disease.

Prediction of Freezing of Gait in Parkinson's disease based on multi-channel time-series neural network

Freezing of Gait (FOG) is a noticeable symptom of Parkinson's disease, like being stuck in place and increasing the risk of falls. The wearable multi-channel sensor system is an efficient method to predict and monitor the FOG, thus warning the wearer to avoid falls and improving the quality of life. However, the existing approaches for the prediction of FOG mainly focus on a single sensor system and cannot handle the interference between multi-channel wearable sensors. Hence, we propose a novel multi-channel time-series neural network (MCT-Net) approach to merge multi-channel gait features into a comprehensive prediction framework, alerting patients to FOG symptoms in advance. Owing to the causal distributed convolution, MCT-Net is a real-time method available to give optimal prediction earlier and implemented in remote devices. Moreover, intra-channel and inter-channel transformers of MCT-Net extract and integrate different sensor position features into a unified deep learning model. Compared with four other state-of-the-art FOG prediction baselines, the proposed MCT-Net obtains 96.21% in accuracy and 80.46% in F1-score on average 2 s before FOG occurrence, demonstrating the superiority of MCT-Net.

A neurotherapeutic approach with Lacticaseibacillus rhamnosus E9 on gut microbiota and intestinal barrier in MPTP-induced mouse model of Parkinson's disease

The gut microbiota plays a crucial role in neural development and progression of neural disorders like Parkinson's disease (PD). Probiotics have been suggested to impact neurodegenerative diseases via gut-brain axis. This study aims to investigate the therapeutic potential of Lacticaseibacillus rhamnosus E9, a high exopolysaccharide producer, on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced mouse model of PD. C57BL/6 mice subjected to MPTP were fed L. rhamnosus E9 for fifteen days and sacrificed after the last administration. Motor functions were determined by open-field, catalepsy, and wire-hanging tests. The ileum and the brain tissues were collected for ELISA, qPCR, and immunohistochemistry analyses. The cecum content was obtained for microbiota analysis. E9 supplementation alleviated MPTP-induced motor dysfunctions accompanied by decreased levels of striatal TH and dopamine. E9 also reduced the level of ROS in the striatum and decreased the DAT expression while increasing the DR1. Furthermore, E9 improved intestinal integrity by enhancing ZO-1 and Occludin levels and reversed the dysbiosis of the gut microbiota induced by MPTP. In conclusion, E9 supplementation improved the MPTP-induced motor deficits and neural damage as well as intestinal barrier by modulating the gut microbiota in PD mice. These findings suggest that E9 supplementation holds therapeutic potential in managing PD through the gut-brain axis.

Emerging perspectives on precision therapy for Parkinson's disease: multidimensional evidence leading to a new breakthrough in personalized medicine

PD is a prevalent and progressive neurodegenerative disorder characterized by both motor and non-motor symptoms. Genes play a significant role in the onset and progression of the disease. While the complexity and pleiotropy of gene expression networks have posed challenges for gene-targeted therapies, numerous pathways of gene variant expression show promise as therapeutic targets in preclinical studies, with some already in clinical trials. With the recognition of the numerous genes and complex pathways that can influence PD, it may be possible to take a novel approach to choose a treatment for the condition. This approach would be based on the symptoms, genomics, and underlying mechanisms of the disease. We discuss the utilization of emerging genetic and pathological knowledge of PD patients to categorize the disease into subgroups. Our long-term objective is to generate new insights for the therapeutic approach to the disease, aiming to delay and treat it more effectively, and ultimately reduce the burden on individuals and society.

Whole-exome sequencing identifies protein-coding variants associated with brain iron in 29,828 individuals

Iron plays a fundamental role in multiple brain disorders. However, the genetic underpinnings of brain iron and its implications for these disorders are still lacking. Here, we conduct an exome-wide association analysis of brain iron, measured by quantitative susceptibility mapping technique, across 26 brain regions among 26,789 UK Biobank participants. We find 36 genes linked to brain iron, with 29 not being previously reported, and 16 of them can be replicated in an independent dataset with 3,039 subjects. Many of these genes are involved in iron transport and homeostasis, such as FTH1 and MLX. Several genes, while not previously connected to brain iron, are associated with iron-related brain disorders like Parkinson's (STAB1, KCNA10), Alzheimer's (SHANK1), and depression (GFAP). Mendelian randomization analysis reveals six causal relationships from regional brain iron to brain disorders, such as from the hippocampus to depression and from the substantia nigra to Parkinson's. These insights advance our understanding of the genetic architecture of brain iron and offer potential therapeutic targets for brain disorders.

Role of Amyloidogenic and Non-Amyloidogenic Protein Spaces in Neurodegenerative Diseases and their Mitigation Using Theranostic Agents

Neurodegenerative diseases (NDDs) refer to a complex heterogeneous group of diseases which are associated with the accumulation of amyloid fibrils or plaques in the brain leading to progressive loss of neuronal functions. Alzheimer's disease is one of the major NDD responsible for 60-80 % of all dementia cases. Currently, there are no curative or disease-reversing/modifying molecules for many of the NDDs except a few such as donepezil, rivastigmine, galantamine, carbidopa and levodopa which treat the disease-associated symptoms. Similarly, there are very few FDA-approved tracers such as flortaucipir (Tauvid) for tau fibril imaging and florbetaben (Neuraceq), flutemetamol (Vizamyl), and florbetapir (Amyvid) for amyloid imaging available for diagnosis. Recent advances in the cryogenic electron microscopy reported distinctly different microstructures for tau fibrils associated with different tauopathies highlighting the possibility to develop tauopathy-specific imaging agents and therapeutics. In addition, it is important to identify the proteins that are associated with disease development and progression to know about their 3D structure to develop various diagnostics, therapeutics and theranostic agents. The current article discusses in detail the disease-associated amyloid and non-amyloid proteins along with their structural insights. We comprehensively discussed various novel proteins associated with NDDs and their implications in disease pathology. In addition, we document various emerging chemical compounds developed for diagnosis and therapy of different NDDs with special emphasis on theranostic agents for better management of NDDs.

Risk factors and intervention of caregiver burden in Parkinson's disease: a systematic review and meta-analysis

PURPOSE

This study summarized characteristics and risk factors of caregiver burden in PD patients and used meta-analysis to verify the effectiveness of the intervention on caregiver burden.

METHODS

Systematic review and meta-analysis were conducted.

RESULTS

Forty-nine articles that involved 5387 caregivers of patients with PD were included in this study. Results of systematic review indicated that Zarit burden Inventory (ZBI) was the most used scale to measure the caregiver burden. All scales revealed caregivers of PD patients had mild to moderate caregiver burden. For the PD patients with longer disease duration, severer disease severity, more negative emotion and cognition impairment, their caregivers intended to have higher caregiver burden. The caregiver with negative emotion and who spent more time on caregiving indicated higher caregiver burden than the others. The caregiver burden was not improved after deep brain stimulation (DBS). Meta-analysis showed that cognitive behavior therapy and palliative care had no significant effect to reduce caregiver burden in PD patients' caregiver.

CONCLUSION

Caregivers of PD patients experienced mild to moderate caregiver burden. Demographic factor, diseased-related factor and negative emotional factor were the risk factors of caregiver burden. Health education and care support for long-term management after DBS surgery should be provided for patients and caregivers to decrease caregiver burden.

Plant-derived bioactive compounds and their novel role in central nervous system disorder treatment via ATF4 targeting: A systematic literature review

Central nervous system (CNS) disorders exhibit exceedingly intricate pathogenic mechanisms. Pragmatic and effective solutions remain elusive, significantly compromising human life and health. Activating transcription factor 4 (ATF4) participates in the regulation of multiple pathophysiological processes, including CNS disorders. Considering the widespread involvement of ATF4 in the pathological process of CNS disorders, the targeted regulation of ATF4 by plant-derived bioactive compounds (PDBCs) may become a viable strategy for the treatment of CNS disorders. However, the regulatory relationship between PDBCs and ATF4 remains incompletely understood. Here, we aimed to comprehensively review the studies on PDBCs targeting ATF4 to ameliorate CNS disorders, thereby offering novel directions and insights for the treatment of CNS disorders. A computerized search was conducted on PubMed, Embase, Web of Science, and Google Scholar databases to identify preclinical experiments related to PDBCs targeting ATF4 for the treatment of CNS disorders. The search timeframe was from the inception of the databases to December 2023. Two assessors conducted searches using the keywords "ATF4," "Central Nervous System," "Neurological," "Alzheimer's disease," "Parkinson's Disease," "Stroke," "Spinal Cord Injury," "Glioblastoma," "Traumatic Brain Injury," and "Spinal Cord Injury." Overall, 31 studies were included, encompassing assessments of 27 PDBCs. Combining results from in vivo and in vitro studies, we observed that these PDBCs, via ATF4 modulation, prevent the deposition of amyloid-like fibers such as Aβ, tau, and α-synuclein. They regulate ERS, reduce the release of inflammatory factors, restore mitochondrial membrane integrity to prevent oxidative stress, regulate synaptic plasticity, modulate autophagy, and engage anti-apoptotic mechanisms. Consequently, they exert neuroprotective effects in CNS disorders. Numerous PDBCs targeting ATF4 have shown potential in facilitating the restoration of CNS functionality, thereby presenting expansive prospects for the treatment of such disorders. However, future endeavors necessitate high-quality, large-scale, and comprehensive preclinical and clinical studies to further validate this therapeutic potential.

Equine Pergolide Toxicity: A Case Series

Veterinary medication exposure may result in human toxicity, with approximately 6,000 exposures to veterinary-only medications reported to poison centers in 2022. There is a paucity of literature on the management of poisoned patients secondary to pharmaceuticals intended for equine use. Pergolide is a dopamine and serotonin receptor agonist and is currently approved to treat equine Cushing's disease. It was previously approved in the United States (US) to treat Parkinson's disease in humans; however, it was withdrawn from the market in 2007 due to its association with valvular heart disease. We report two cases of pergolide toxicity in horse owners following unintentional ingestions. Both patients experienced similar clinical presentations resulting from their unintentional pergolide ingestions. Veterinary medication ingestion presents a unique challenge to clinicians as the drug may have limited human toxicity data and/or recommended animal dosing may differ greatly from human dosing. Case reports of human toxicity may assist with anticipating the clinical course and guiding medical decision-making.