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The Lancet. Neurology May 2021Parkinson's disease is the second most common neurodegenerative disease and its prevalence has been projected to double over the next 30 years. An accurate diagnosis of... (Review)
Review
Parkinson's disease is the second most common neurodegenerative disease and its prevalence has been projected to double over the next 30 years. An accurate diagnosis of Parkinson's disease remains challenging and the characterisation of the earliest stages of the disease is ongoing. Recent developments over the past 5 years include the validation of clinical diagnostic criteria, the introduction and testing of research criteria for prodromal Parkinson's disease, and the identification of genetic subtypes and a growing number of genetic variants associated with risk of Parkinson's disease. Substantial progress has been made in the development of diagnostic biomarkers, and genetic and imaging tests are already part of routine protocols in clinical practice, while novel tissue and fluid markers are under investigation. Parkinson's disease is evolving from a clinical to a biomarker-supported diagnostic entity, for which earlier identification is possible, different subtypes with diverse prognosis are recognised, and novel disease-modifying treatments are in development.
Topics: Diagnosis, Differential; Disease Progression; Humans; Magnetic Resonance Imaging; Parkinson Disease; Symptom Assessment
PubMed: 33894193
DOI: 10.1016/S1474-4422(21)00030-2 -
Annual Review of Pathology Jan 2023Parkinson's disease (PD) is clinically, pathologically, and genetically heterogeneous, resisting distillation to a single, cohesive disorder. Instead, each affected... (Review)
Review
Parkinson's disease (PD) is clinically, pathologically, and genetically heterogeneous, resisting distillation to a single, cohesive disorder. Instead, each affected individual develops a virtually unique form of Parkinson's syndrome. Clinical manifestations consist of variable motor and nonmotor features, and myriad overlaps are recognized with other neurodegenerative conditions. Although most commonly characterized by alpha-synuclein protein pathology throughout the central and peripheral nervous systems, the distribution varies and other pathologies commonly modify PD or trigger similar manifestations. Nearly all PD is genetically influenced. More than 100 genes or genetic loci have been identified, and most cases likely arise from interactions among many common and rare genetic variants. Despite its complex architecture, insights from experimental genetic dissection coalesce to reveal unifying biological themes, including synaptic, lysosomal, mitochondrial, andimmune-mediated mechanisms of pathogenesis. This emerging understanding of Parkinson's syndrome, coupled with advances in biomarkers and targeted therapies, presages successful precision medicine strategies.
Topics: Humans; Parkinson Disease; Mitochondria; Mutation
PubMed: 36100231
DOI: 10.1146/annurev-pathmechdis-031521-034145 -
Acta Medica Portuguesa Oct 2019Parkinson's disease is the second most common neurodegenerative disorder, and a significant increase in its prevalence in the past three decades has been documented.... (Review)
Review
Parkinson's disease is the second most common neurodegenerative disorder, and a significant increase in its prevalence in the past three decades has been documented. Environmental and genetic factors contribute to the pathophysiology of this disease, and 5% - 10% of cases have a monogenic cause. The diagnosis relies on clinical findings, supported by adequate testing. There is no absolute method to diagnose Parkinson's disease in vivo, except for genetic testing in specific circumstances, whose usefulness is limited to a minority of cases. New diagnostic criteria have been recently proposed with the aim of improving diagnostic accuracy, emphasizing findings that might point to other causes of parkinsonism. The available therapeutic options are clinically useful, as they improve the symptoms as well as the quality of life of patients. After the introduction of levodopa, deep brain stimulation emerged as the second therapy with an important symptomatic impact in the treatment of Parkinson's disease. Non-motor symptoms and motor complications are responsible for a large proportion of disability, so these should be identified and treated. Current scientific research is focused on the identification of disease biomarkers allowing correct and timely diagnosis, and on creating more effective therapies, thus fulfilling current clinical unmet needs. This paper presents an updated review on Parkinson's disease, guiding the readership through current concepts, and allowing their application to daily clinical practice.
Topics: Antiparkinson Agents; Biomarkers; Deep Brain Stimulation; Diagnosis, Differential; Humans; Levodopa; Parkinson Disease; Symptom Assessment
PubMed: 31625879
DOI: 10.20344/amp.11978 -
Journal of Neural Transmission (Vienna,... May 2020The substantial contributions of Dr. Gerald Stern to past and current treatments for Parkinson's disease patients are reviewed, which form the foundation for an... (Review)
Review
The substantial contributions of Dr. Gerald Stern to past and current treatments for Parkinson's disease patients are reviewed, which form the foundation for an evaluation of future options to control symptoms and halt progression of the disease. These opportunities will depend on a greater understanding of the relative contributions of the environment, genetic and epigenetic influences to disease onset, and promise to emerge as strategies for improving mitochondrial function, halting accumulation of synuclein and neuromelanin, in addition to refinement of stem cell and gene therapies. Such advances will be achieved through deployment of improved models for the disease.
Topics: History, 20th Century; History, 21st Century; Humans; Neurology; Parkinson Disease
PubMed: 32172471
DOI: 10.1007/s00702-020-02167-1 -
RoFo : Fortschritte Auf Dem Gebiete Der... Dec 2021Diagnosis of Parkinson's disease and atypical parkinsonism is based on clinical evaluation of the patient's symptoms and on magnetic resonance imaging (MRI) of the... (Review)
Review
BACKGROUND
Diagnosis of Parkinson's disease and atypical parkinsonism is based on clinical evaluation of the patient's symptoms and on magnetic resonance imaging (MRI) of the brain, which can be supplemented by nuclear medicine techniques. MRI plays a leading role in the differentiation between Parkinson's disease and atypical parkinsonism. While atypical parkinsonism is characterized by relatively specific MRI signs, imaging of Parkinson's disease previously lacked such signs. However, high-field MRI and new optimized MRI sequences now make it possible to define specific MRI signs of Parkinson's disease and have significant potential regarding differentiated imaging, early diagnosis, and imaging of disease progression.
METHODS
PubMed was selectively searched for literature regarding the definition and discussion of specific MRI signs of Parkinson's disease, as well as the most common types of atypical parkinsonism with a leading motor component. No time frame was set, but the search was particularly focused on current literature.
RESULTS
This review article discusses the different MRI signs of Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy. The pathogenesis of the MRI signs is described, and imaging examples are given. The technical aspects of image acquisition are briefly defined, and the different signs are discussed and compared with regard to their diagnostic significance according to current literature.
CONCLUSION
The MRI signs of Parkinson's disease, which can be defined with high-field MRI and new optimized MRI sequences, enable differentiated structural image interpretation and consecutive diagnostic workup. Despite the fact that the signs are in need of further validation by bigger studies, they have the potential to achieve significant diagnostic relevance regarding the imaging of Parkinson's disease and atypical parkinsonism.
KEY POINTS
· High-field MRI and specialized sequences make it possible to define specific MRI signs for neurodegenerative disorders. · Cerebral alterations can be detected in prodromal stages of Parkinson's disease. · The combination of specific MRI signs makes it possible to differentiate between Parkinson's disease and atypical parkinsonism.
CITATION FORMAT
· Aludin S, Schmill LA. MRI Signs of Parkinson's Disease and Atypical Parkinsonism. Fortschr Röntgenstr 2021; 193: 1403 - 1410.
Topics: Humans; Magnetic Resonance Imaging; Multiple System Atrophy; Parkinson Disease; Parkinsonian Disorders; Supranuclear Palsy, Progressive
PubMed: 34034347
DOI: 10.1055/a-1460-8795 -
Journal of Parkinson's Disease 2022Early-onset parkinsonism (EO parkinsonism), defined as subjects with disease onset before the age of 40 or 50 years, can be the main clinical presentation of a variety... (Review)
Review
Early-onset parkinsonism (EO parkinsonism), defined as subjects with disease onset before the age of 40 or 50 years, can be the main clinical presentation of a variety of conditions that are important to differentiate. Although rarer than classical late-onset Parkinson's disease (PD) and not infrequently overlapping with forms of juvenile onset PD, a correct diagnosis of the specific cause of EO parkinsonism is critical for offering appropriate counseling to patients, for family and work planning, and to select the most appropriate symptomatic or etiopathogenic treatments. Clinical features, radiological and laboratory findings are crucial for guiding the differential diagnosis. Here we summarize the most important conditions associated with primary and secondary EO parkinsonism. We also proposed a practical approach based on the current literature and expert opinion to help movement disorders specialists and neurologists navigate this complex and challenging landscape.
Topics: Diagnosis, Differential; Humans; Middle Aged; Neurologists; Parkinson Disease; Parkinsonian Disorders
PubMed: 34569973
DOI: 10.3233/JPD-212815 -
Journal of Parkinson's Disease 2022Fueled by aging populations and continued environmental contamination, the global burden of Parkinson's disease (PD) is increasing. The disease, or more appropriately... (Review)
Review
Fueled by aging populations and continued environmental contamination, the global burden of Parkinson's disease (PD) is increasing. The disease, or more appropriately diseases, have multiple environmental and genetic influences but no approved disease modifying therapy. Additionally, efforts to prevent this debilitating disease have been limited. As numerous environmental contaminants (e.g., pesticides, metals, industrial chemicals) are implicated in PD, disease prevention is possible. To reduce the burden of PD, we have compiled preclinical and clinical research priorities that highlight both disease prediction and primary prevention. Though not exhaustive, the "PD prevention agenda" builds upon many years of research by our colleagues and proposes next steps through the lens of modifiable risk factors. The agenda identifies ten specific areas of further inquiry and considers the funding and policy changes that will be necessary to help prevent the world's fastest growing brain disease.
Topics: Humans; Parkinson Disease; Pesticides
PubMed: 34719434
DOI: 10.3233/JPD-212922 -
International Journal of Molecular... Nov 2020Parkinson's disease (PD) is a neurodegenerative disorder, caused by, so far, unknown pathogenetic mechanisms. There is no doubt that pro-inflammatory immune-mediated... (Review)
Review
Parkinson's disease (PD) is a neurodegenerative disorder, caused by, so far, unknown pathogenetic mechanisms. There is no doubt that pro-inflammatory immune-mediated mechanisms are pivotal to the pathogenicity and progression of the disease. In this review, we highlight the binary role of microglia activation in the pathophysiology of the disorder, both neuroprotective and neuromodulatory. We present how the expression of several cytokines implicated in dopaminergic neurons (DA) degeneration could be used as biomarkers for PD. Viral infections have been studied and correlated to the disease progression, usually operating as trigger factors for the inflammatory process. The gut-brain axis and the possible contribution of the peripheral bowel inflammation to neuronal death, mainly dopaminergic neurons, seems to be a main contributor of brain neuroinflammation. The role of the immune system has also been analyzed implicating a-synuclein in the activation of innate and adaptive immunity. We also discuss therapeutic approaches concerning PD and neuroinflammation, which have been studied in experimental and in vitro models and data stemming from epidemiological studies.
Topics: Animals; Autoimmunity; Biomarkers; Cytokines; Dopaminergic Neurons; Humans; Inflammation; Microglia; Nerve Degeneration; Parkinson Disease; Parkinsonian Disorders; Signal Transduction; Virus Diseases; alpha-Synuclein
PubMed: 33182554
DOI: 10.3390/ijms21228421 -
Genes Mar 2022Parkinson's disease may be caused by a single pathogenic variant (monogenic) in 5-10% of cases, but investigation of these disorders provides valuable pathophysiological... (Review)
Review
Parkinson's disease may be caused by a single pathogenic variant (monogenic) in 5-10% of cases, but investigation of these disorders provides valuable pathophysiological insights. In this review, we discuss each genetic form with a focus on genotype, phenotype, pathophysiology, and the geographic and ethnic distribution. Well-established Parkinson's disease genes include autosomal dominant forms (, , and ) and autosomal recessive forms (, and ). Furthermore, mutations in the gene are a key risk factor for Parkinson's disease, and there have been major developments for X-linked dystonia parkinsonism. Moreover, atypical or complex parkinsonism may be due to mutations in genes such as , , , , , and . Furthermore, numerous genes have recently been implicated in Parkinson's disease, such as , , , , and . Additionally, we discuss the role of heterozygous mutations in autosomal recessive genes, the effect of having mutations in two Parkinson's disease genes, the outcome of deep brain stimulation, and the role of genetic testing. We highlight that monogenic Parkinson's disease is influenced by ethnicity and geographical differences, reinforcing the need for global efforts to pool large numbers of patients and identify novel candidate genes.
Topics: DNA-Binding Proteins; Genetic Testing; Genotype; Humans; Membrane Proteins; Parkinson Disease; Parkinsonian Disorders; Phenotype; Transcription Factors
PubMed: 35328025
DOI: 10.3390/genes13030471 -
Journal of Neurochemistry Nov 2021Parkinson's disease (PD) is a neurodegenerative disorder that affects millions of people worldwide. Two hallmarks of PD are the accumulation of alpha-synuclein and the... (Review)
Review
Parkinson's disease (PD) is a neurodegenerative disorder that affects millions of people worldwide. Two hallmarks of PD are the accumulation of alpha-synuclein and the loss of dopaminergic neurons in the brain. There is no cure for PD, and all existing treatments focus on alleviating the symptoms. PD diagnosis is also based on the symptoms, such as abnormalities of movement, mood, and cognition observed in the patients. Molecular imaging methods such as magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), and positron emission tomography (PET) can detect objective alterations in the neurochemical machinery of the brain and help diagnose and study neurodegenerative diseases. This review addresses the application of functional MRI, PET, and SPECT in PD patients. We provide an overview of the imaging targets, discuss the rationale behind target selection, the agents (tracers) with which the imaging can be performed, and the main findings regarding each target's state in PD. Molecular imaging has proven itself effective in supporting clinical diagnosis of PD and has helped reveal that PD is a heterogeneous disorder, which has important implications for the development of future therapies. However, the application of molecular imaging for early diagnosis of PD or for differentiation between PD and atypical parkinsonisms has remained challenging. The final section of the review is dedicated to new imaging targets with which one can detect the PD-related pathological changes upstream from dopaminergic degeneration. The foremost of those targets is alpha-synuclein. We discuss the progress of tracer development achieved so far and challenges on the path toward alpha-synuclein imaging in humans.
Topics: Humans; Neuroimaging; Parkinson Disease; Positron-Emission Tomography; Tomography, Emission-Computed, Single-Photon; alpha-Synuclein
PubMed: 34532856
DOI: 10.1111/jnc.15516