Non-motor symptoms in Parkinson's disease: Opening new avenues in treatment

The p.Gly2019Ser is a common LRRK2 pathogenic variant among Egyptians with familial and sporadic Parkinson's disease

The impact of LRRK2 variants on the risk of Parkinson's disease in Egyptians remains unknown. We examined 1210 Egyptians (611 PD patients and 599 controls) from 16 governorates across Egypt for 12 LRRK2 pathogenic variants. The p.Gly2019Ser was the only variant detected, with a prevalence of 4.1% in sporadic cases, 6.5% in familial cases, and 0.68% in controls. Among p.Gly2019Ser carriers, all were heterozygous bar one homozygous patient, and all shared the common haplotype 1. Demographics and UPDRS scores did not differ between carriers and non-carriers, with most patients being males and developed PD in their fifties. Young and Early-onset PD prevalence was 37.5% in carriers and 33% in non-carriers. Familial cases were 16.6% in carriers and 11.5% in non-carriers. This study affirms that like other Mediterranean populations, Egyptians with PD have a higher prevalence of the p.Gly2019Ser variant compared to the global average. LRRK2 inhibitors could be promising therapeutic options for further exploration in this population.

Neuronal threshold functions: Determining symptom onset in neurological disorders

Synaptic networks determine brain function. Highly complex interconnected brain synaptic networks provide output even under fluctuating or pathological conditions. Relevant to the treatment of brain disorders, understanding the limitations of such functional networks becomes paramount. Here we use the example of Parkinson's Disease (PD) as a system disorder, with PD symptomatology emerging only when the functional reserves of neurons, and their interconnected networks, are unable to facilitate effective compensatory mechanisms. We have denoted this the "threshold theory" to account for how PD symptoms develop in sequence. In this perspective, threshold functions are delineated in a quantitative, synaptic, and cellular network context. This provides a framework to discuss the development of specific symptoms. PD includes dysfunction and degeneration in many organ systems and both peripheral and central nervous system involvement. The threshold theory accounts for and explains the reasons why parallel gradually emerging pathologies in brain and peripheral systems generate specific symptoms only when functional thresholds are crossed, like tipping points. New and mounting evidence demonstrate that PD and related neurodegenerative diseases are multisystem disorders, which transcends the traditional brain-centric paradigm. We believe that representation of threshold functions will be helpful to develop new medicines and interventions that are specific for both pre- and post-symptomatic periods of neurodegenerative disorders.

Alpha Synuclein Toxicity and Non-Motor Parkinson's

Parkinson's disease (PD) is a common multisystem neurodegenerative disorder affecting 1% of the population over the age of 60 years. The main neuropathological features of PD are the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the presence of alpha synuclein (αSyn)-rich Lewy bodies both manifesting with classical motor signs. αSyn has emerged as a key protein in PD pathology as it can spread through synaptic networks to reach several anatomical regions of the body contributing to the appearance of non-motor symptoms (NMS) considered prevalent among individuals prior to PD diagnosis and persisting throughout the patient's life. NMS mainly includes loss of taste and smell, constipation, psychiatric disorders, dementia, impaired rapid eye movement (REM) sleep, urogenital dysfunction, and cardiovascular impairment. This review summarizes the more recent findings on the impact of αSyn deposits on several prodromal NMS and emphasizes the importance of early detection of αSyn toxic species in biofluids and peripheral biopsies as prospective biomarkers in PD.

Neuropsychological Assessment for Early Detection and Diagnosis of Dementia: Current Knowledge and New Insights

Dementia remains an underdiagnosed syndrome, and there is a need to improve the early detection of cognitive decline. This narrative review examines the role of neuropsychological assessment in the characterization of cognitive changes associated with dementia syndrome at different states. The first section describes the early indicators of cognitive decline and the major barriers to their identification. Further, the optimal cognitive screening conditions and the most widely accepted tests are described. The second section analyzes the main differences in cognitive performance between Alzheimer's disease and other subtypes of dementia. Finally, the current challenges of neuropsychological assessment in aging/dementia and future approaches are discussed. Essentially, we find that current research is beginning to uncover early cognitive changes that precede dementia, while continuing to improve and refine the differential diagnosis of neurodegenerative disorders that cause dementia. However, neuropsychology faces several barriers, including the cultural diversity of the populations, a limited implementation in public health systems, and the adaptation to technological advances. Nowadays, neuropsychological assessment plays a fundamental role in characterizing cognitive decline in the different stages of dementia, but more efforts are needed to develop harmonized procedures that facilitate its use in different clinical contexts and research protocols.

Amyloid-induced neurodegeneration: A comprehensive review through aggregomics perception of proteins in health and pathology

Amyloidosis of protein caused by fibrillation and aggregation are some of the most exciting new edges not only in protein sciences but also in molecular medicines. The present review discusses recent advancements in the field of neurodegenerative diseases and therapeutic applications with ongoing clinical trials, featuring new areas of protein misfolding resulting in aggregation. The endogenous accretion of protein fibrils having fibrillar morphology symbolizes the beginning of neuro-disorders. Prognostic amyloidosis is prominent in numerous degenerative infections such as Alzheimer's and Parkinson's disease, Amyotrophic lateral sclerosis (ALS), etc. However, the molecular basis determining the intracellular or extracellular evidence of aggregates, playing a significant role as a causative factor in neurodegeneration is still unclear. Structural conversions and protein self-assembly resulting in the formation of amyloid oligomers and fibrils are important events in the pathophysiology of the disease. This comprehensive review sheds light on the evolving landscape of potential treatment modalities, highlighting the ongoing clinical trials and the potential socio-economic impact of novel therapeutic interventions in the realm of neurodegenerative diseases. Furthermore, many drugs are undergoing different levels of clinical trials that would certainly help in treating these disorders and will surely improve the socio-impact of human life.

Retinal Alterations Predict Early Prodromal Signs of Neurodegenerative Disease

Neurodegenerative diseases are an increasingly common group of diseases that occur late in life with a significant impact on personal, family, and economic life. Among these, Alzheimer's disease (AD) and Parkinson's disease (PD) are the major disorders that lead to mild to severe cognitive and physical impairment and dementia. Interestingly, those diseases may show onset of prodromal symptoms early after middle age. Commonly, the evaluation of these neurodegenerative diseases is based on the detection of biomarkers, where functional and structural magnetic resonance imaging (MRI) have shown a central role in revealing early or prodromal phases, although it can be expensive, time-consuming, and not always available. The aforementioned diseases have a common impact on the visual system due to the pathophysiological mechanisms shared between the eye and the brain. In Parkinson's disease, α-synuclein deposition in the retinal cells, as well as in dopaminergic neurons of the substantia nigra, alters the visual cortex and retinal function, resulting in modifications to the visual field. Similarly, the visual cortex is modified by the neurofibrillary tangles and neuritic amyloid β plaques typically seen in the Alzheimer's disease brain, and this may reflect the accumulation of these biomarkers in the retina during the early stages of the disease, as seen in postmortem retinas of AD patients. In this light, the ophthalmic evaluation of retinal neurodegeneration could become a cost-effective method for the early diagnosis of those diseases, overcoming the limitations of functional and structural imaging of the deep brain. This analysis is commonly used in ophthalmic practice, and interest in it has risen in recent years. This review will discuss the relationship between Alzheimer's disease and Parkinson's disease with retinal degeneration, highlighting how retinal analysis may represent a noninvasive and straightforward method for the early diagnosis of these neurodegenerative diseases.

Advancements in Genetic and Biochemical Insights: Unraveling the Etiopathogenesis of Neurodegeneration in Parkinson's Disease

Parkinson's disease (PD) is the second most prevalent neurodegenerative movement disorder worldwide, which is primarily characterized by motor impairments. Even though multiple hypotheses have been proposed over the decades that explain the pathogenesis of PD, presently, there are no cures or promising preventive therapies for PD. This could be attributed to the intricate pathophysiology of PD and the poorly understood molecular mechanism. To address these challenges comprehensively, a thorough disease model is imperative for a nuanced understanding of PD's underlying pathogenic mechanisms. This review offers a detailed analysis of the current state of knowledge regarding the molecular mechanisms underlying the pathogenesis of PD, with a particular emphasis on the roles played by gene-based factors in the disease's development and progression. This study includes an extensive discussion of the proteins and mutations of primary genes that are linked to PD, including α-synuclein, GBA1, LRRK2, VPS35, PINK1, DJ-1, and Parkin. Further, this review explores plausible mechanisms for DAergic neural loss, non-motor and non-dopaminergic pathologies, and the risk factors associated with PD. The present study will encourage the related research fields to understand better and analyze the current status of the biochemical mechanisms of PD, which might contribute to the design and development of efficacious and safe treatment strategies for PD in future endeavors.

[Sarcopenia as a non-motor symptom of Parkinson's disease]

Sarcopenia is a progressive generalized skeletal muscle disease that is accompanied by an accelerated loss of muscle mass and function, affecting the quality of life and the ability to perform self-care. The prevalence of sarcopenia in the world today ranges from 10 to 25%, which represents a certain danger as it is a prognostic factor for possible injury and increased disability in the elderly population. Sarcopenia often accompanies a large number of different diseases, including neurodegenerative ones, so it is actively studied in this category of patients, for example, as one of the early symptoms of Parkinson's disease (PD). PD and sarcopenia have overlapping pathophysiological mechanisms of muscle fiber loss: inflammation, muscle autophagy, oxidative stress and apoptosis. Loss of muscle mass due to malnutrition is common in PD. According to some studies, the prevalence of sarcopenia in PD varies from 6 to 55.8%; weakness and sarcopenia are more common in patients with PD than in society as a whole, which is associated with an unfavorable course of the disease. The presence of both diseases simultaneously in one patient can impose certain restrictions on the treatment of the patient, worsen his physical and mental condition, which determines the need for early detection of sarcopenia in patients with PD.

Unveiling the Hidden Challenges: Non-Motor Disorders in Parkinson's Disease

Parkinson's disease (PD) is not just a motor disorder, it is a complex condition that affects every aspect of a patient's life, from cognitive impairment and psychiatric disturbances to autonomic dysfunction and sleep disturbances [...].

Shared and Unique Disease Pathways in Amyotrophic Lateral Sclerosis and Parkinson's Disease Unveiled in Peripheral Blood Mononuclear Cells

Recent evidence supports an association between amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD). Indeed, prospective population-based studies demonstrated that about one-third of ALS patients develop parkinsonian (PK) signs, even though different neuronal circuitries are involved. In this context, proteomics represents a valuable tool to identify unique and shared pathological pathways. Here, we used two-dimensional electrophoresis to obtain the proteomic profile of peripheral blood mononuclear cells (PBMCs) from PD and ALS patients including a small cohort of ALS patients with parkinsonian signs (ALS-PK). After the removal of protein spots correlating with confounding factors, we applied a sparse partial least square discriminant analysis followed by recursive feature elimination to obtain two protein classifiers able to discriminate (i) PD and ALS patients (30 spots) and (ii) ALS-PK patients among all ALS subjects (20 spots). Functionally, the glycolysis pathway was significantly overrepresented in the first signature, while extracellular interactions and intracellular signaling were enriched in the second signature. These results represent molecular evidence at the periphery for the classification of ALS-PK as ALS patients that manifest parkinsonian signs, rather than comorbid patients suffering from both ALS and PD. Moreover, we confirmed that low levels of fibrinogen in PBMCs is a characteristic feature of PD, also when compared with another movement disorder. Collectively, we provide evidence that peripheral protein signatures are a tool to differentially investigate neurodegenerative diseases and highlight altered biochemical pathways.

"Out and proud…. in all your shaking glory" the wellbeing impact of a dance program with public dance performance for people with Parkinson's disease: a qualitative study

PURPOSE

To explore if and how Parkinson's disease dance class participation and public performance contributes to perceptions of wellbeing.

MATERIALS AND METHODS

A qualitative design using audio-recorded one-on-one semi-structured interviews with five class participants and three teachers/volunteers from two metropolitan Dance for Wellbeing class locations. Data were inductively thematically analysed by three researchers.

RESULTS

Five themes illustrated the experience of dance class and performance for people with Parkinson's Disease: 1) 'the enabling learning environment'; 2) 'physical benefits from class participation; 3) 'mental/psychological benefits from class participation'; 4) 'social benefits from class participation; 5) 'sense of self and life engagement from class participation'. Themes 4 and 5 in particular were considered to be 'magnified by public performance', providing an opportunity for solidarity within the group and a supportive avenue for "coming out" and living publicly with the PD diagnosis.

CONCLUSION

Dance performance magnifies health and wellbeing experiences of people with Parkinson's disease when part of an enabling, inclusive and emotionally and physically safe learning dance class environment. Elements of holistic benefits, as well as the fun and playful nature of the experience may be important elements to consider for motivation, recruitment and retention in this population.IMPLICATIONS FOR REHABILITATIONRehabilitation professionals should consider the use of dance class as an art-based activity that has a holistic therapeutic benefit.Flexible and fun environments are constructive for dancers to sustain attendance and interest.Rehabilitation professionals can be cognisant of the impact of public dance performance as 'coming out' with Parkinson's Disease.

The anterior olfactory nucleus revisited - an emerging role for neuropathological conditions?

Olfaction is an important sensory modality for many species and greatly influences animal and human behavior. Still, much about olfactory perception remains unknown. The anterior olfactory nucleus is one of the brain's central early olfactory processing areas. Located directly posterior to the olfactory bulb in the olfactory peduncle with extensive in- and output connections and unique cellular composition, it connects olfactory processing centers of the left and right hemispheres. Almost 20 years have passed since the last comprehensive review on the anterior olfactory nucleus has been published and significant advances regarding its anatomy, function, and pathophysiology have been made in the meantime. Here we briefly summarize previous knowledge on the anterior olfactory nucleus, give detailed insights into the progress that has been made in recent years, and map out its emerging importance in translational research of neurological diseases.

Both Motor and Non-Motor Fluctuations Matter in the Clinical Management of Patients with Parkinson's Disease: An Exploratory Study

Non-motor symptoms (NMS) characterize the Parkinson's disease (PD) clinical picture, and as well as motor fluctuations, PD patients can also experience NMS fluctuations (NMF). The aim of this observational study was to investigate the presence of NMS and NMF in patients with PD using the recently validated Non-Motor Fluctuation Assessment questionnaire (NoMoFa) and to evaluate their associations with disease characteristics and motor impairment. Patients with PD were consecutively recruited, and NMS, NMF, motor impairment, motor fluctuations, levodopa-equivalent daily dose, and motor performance were evaluated. One-third of the 25 patients included in the study (10 females, 15 males, mean age: 69.9 ± 10.3) showed NMF, and patients with NMF presented a higher number of NMS (p < 0.01). Static NMS and NoMoFa total score were positively associated with motor performance assessed with the Global Mobility Task (p < 0.01 and p < 0.001), and the latter was also correlated with motor impairment (p < 0.05) but not with motor fluctuations. Overall, this study shows evidence that NMF are frequently reported by mild-to-moderate PD patients and associated with an increased number of NMS. The relationship between NoMoFa total score and motor functioning highlights the importance of understanding the clinical role of NMS and NMF in the management of PD patients.

Therapeutic drug repositioning with special emphasis on neurodegenerative diseases: Threats and issues

Drug repositioning or repurposing is the process of discovering leading-edge indications for authorized or declined/abandoned molecules for use in different diseases. This approach revitalizes the traditional drug discovery method by revealing new therapeutic applications for existing drugs. There are numerous studies available that highlight the triumph of several drugs as repurposed therapeutics. For example, sildenafil to aspirin, thalidomide to adalimumab, and so on. Millions of people worldwide are affected by neurodegenerative diseases. According to a 2021 report, the Alzheimer's disease Association estimates that 6.2 million Americans are detected with Alzheimer's disease. By 2030, approximately 1.2 million people in the United States possibly acquire Parkinson's disease. Drugs that act on a single molecular target benefit people suffering from neurodegenerative diseases. Current pharmacological approaches, on the other hand, are constrained in their capacity to unquestionably alter the course of the disease and provide patients with inadequate and momentary benefits. Drug repositioning-based approaches appear to be very pertinent, expense- and time-reducing strategies for the enhancement of medicinal opportunities for such diseases in the current era. Kinase inhibitors, for example, which were developed for various oncology indications, demonstrated significant neuroprotective effects in neurodegenerative diseases. This review expounds on the classical and recent examples of drug repositioning at various stages of drug development, with a special focus on neurodegenerative disorders and the aspects of threats and issues viz. the regulatory, scientific, and economic aspects.

Mild cognitive impairment in patients with Parkinson’s disease: An updated mini-review and future outlook

Mild cognitive impairment (MCI) is one of the common non-motor symptoms in patients with Parkinson’s disease (PD). MCI is the transition stage between normal aging and full-blown dementia and is also a powerful predictor of dementia. Although the concept of MCI has been used to describe some of the PD symptoms for many years, there is a lack of consistent diagnostic criteria. Moreover, because of the diverse patterns of the cognitive functions, each cognitive impairment will have a different progression. In this review, we overviewed the diagnostic criteria for PD-MCI, primarily focused on the heterogeneity of PD-MCI patients’ cognitive function, including various types of cognitive functions and their progression rates. A review of this topic is expected to be beneficial for clinical diagnosis, early intervention, and treatment. In addition, we also discussed the unmet needs and future vision in this field.

Chaperone-Mediated Autophagy in Neurodegenerative Diseases: Molecular Mechanisms and Pharmacological Opportunities

Chaperone-mediated autophagy (CMA) is a protein degradation mechanism through lysosomes. By targeting the KFERQ motif of the substrate, CMA is responsible for the degradation of about 30% of cytosolic proteins, including a series of proteins associated with neurodegenerative diseases (NDs). The fact that decreased activity of CMA is observed in NDs, and ND-associated mutant proteins, including alpha-synuclein and Tau, directly impair CMA activity reveals a possible vicious cycle of CMA impairment and pathogenic protein accumulation in ND development. Given the intrinsic connection between CMA dysfunction and ND, enhancement of CMA has been regarded as a strategy to counteract ND. Indeed, genetic and pharmacological approaches to modulate CMA have been shown to promote the degradation of ND-associated proteins and alleviate ND phenotypes in multiple ND models. This review summarizes the current knowledge on the mechanism of CMA with a focus on its relationship with NDs and discusses the therapeutic potential of CMA modulation for ND.

Wearable Walking Assistant for Freezing of Gait With Environmental IoT Monitoring: A Contribution to the Discussion

Parkinson's disease (PD) is the second most common neurodegenerative disease, significantly increasing in the last three decades. Worldwide, seven to ten million people are affected by PD. In people living with PD, freezing of gait (FoG) significantly impacts activities of daily living, potentially leading to falls, injuries, and loss of autonomy. FoG prevalence rates vary widely, reaching at least 50% of patients with PD. Current therapeutic options have limited effectiveness, and their complement with innovative technology-based solutions in the real world is demanded to enhance daily functioning for people living with PD. This article provides a narrative review of current technological developments for people living with PD and, derived from that evidence, presents a perspective on integrating wearable technology and IoT to support telemonitoring and self-management of people living with PD in their daily living environment. Complementing current therapeutic options with technology-based solutions in PD patients' real-world environment is crucial to enhancing the quality of life of people living with PD. In that way, wearable technology and IoT might constitute resources of excellence in seamless monitoring and self-management in people's home environments.

Angiotensin-Converting Enzyme 2 Activation Mitigates Behavioral Deficits and Neuroinflammatory Burden in 6-OHDA Induced Experimental Models of Parkinson's Disease

Hypertension is reported to cause major brain disorders including Parkinson's disease (PD), apart from cardiovascular and chronic kidney disorders. Considering this, for the first time, we explored the effect of modulation of the ACE2/Ang (1-7)/MasR axis using diminazene aceturate (DIZE), an ACE2 activator, in 6-hydroxydopamine (6-OHDA) induced PD model. We found that DIZE treatment improved neuromuscular coordination and locomotor deficits in the 6-OHDA induced PD rat model. Further, the DIZE-mediated activation of ACE2 led to increased tyrosine hydroxylase (TH) and dopamine transporters (DAT) expression in the rat brain, indicating the protection of dopaminergic (DAergic) neurons from 6-OHDA induced neurotoxicity. Moreover, 6-OHDA induced activation of glial cells (astrocytes and microglia) and release of neuroinflammatory mediators were attenuated by DIZE treatment in both in vitro as well as in vivo models of PD. DIZE exerted its effect by activating ACE2 that produced Ang (1-7), a neuroprotective peptide. Ang (1-7) conferred its neuroprotective effect upon binding with the G-protein-coupled MAS receptor that led to the upregulation of cell survival proteins while downregulating apoptotic proteins. Importantly, these findings were further validated by using A-779, a MasR antagonist. The result showed that treatment with A-779 reversed the antioxidative and anti-inflammatory effects of DIZE by decreasing glial activation and neuroinflammatory markers. Although the role of ACE2 in PD pathology needs to be additionally confirmed using transgenic models in either ACE2 overexpressing or knockout mice, still, our study demonstrates that enhancing ACE2 activity could be a novel approach for ameliorating PD pathology.