Open research questions in Parkinson's Disease Mechanisms and Treatments

What the literature leaves open

• Significant gaps in our understanding still remain, - The remarkable heterogeneity of αSyn species complicates the interpretation of experimental findings, - Clinically grouped under a single diagnosis, PD encompasses a spectrum of phenotypes that may arise from distinct and only partially overlapping molecular mechanisms

  Breaking the proteasome balance: α-synuclein and the ubiquitin-proteasome system · 2026 · DOI

• Recognizing and systematically incorporating the variability into experimental design and data interpretation will be essential for progressing research in the field, - Elucidating the molecular basis of proteolytic dysfunction in PD and related neurodegenerative disorders

  Breaking the proteasome balance: α-synuclein and the ubiquitin-proteasome system · 2026 · DOI

• Evidence addressing these questions in Chinese tertiary hospitals remains limited, - Detailed data linking baseline vulnerability, acute illness severity, in-hospital management, and post-discharge outcomes are sparse, - Further research is needed to understand the relationship between PD-specific measures and in-hospital outcomes

  In-hospital outcomes and documented 90-day readmission to the index hospital in older patients with Parkinson’s disease hospitalised for lower respiratory tract infection: a single-centre retrospective cohort study · 2026 · DOI

• study does not demonstrate a direct causal or synergistic regulatory mechanism, - exact cause of PD remains obscure

  Cuproptosis-associated genes DLD, ULK2, CCL8, and CCS link metabolic and immunological dysfunction in Parkinson’s disease: a multi-omics study · 2026 · DOI

• The exact cause of PD remains obscure. The role of cuproptosis in PD is not well understood. There is a need to identify novel biomarkers or characteristics to enhance early clinical decision-making in PD management.

  Cuproptosis-associated genes DLD, ULK2, CCL8, and CCS link metabolic and immunological dysfunction in Parkinson’s disease: a multi-omics study · 2026 · DOI

• investigate the relationship between constipation and cortical hyperactivation in a larger sample, - examine the effects of freezing of gait on motor cortex activity, - explore the potential applications of fNIRS in diagnosing and monitoring Parkinson's Disease

  Distinct brain activation patterns linked to clinical symptoms during hand grasping in Parkinson's disease · 2026 · DOI

• There is a lack of understanding of the neural mechanisms underlying Parkinson's disease. Current therapeutic interventions have limitations, and there is a need to develop more effective treatments. The study aims to address this gap by investigating brain activation patterns in Parkinson's disease patients during a hand grasping task.

  Distinct brain activation patterns linked to clinical symptoms during hand grasping in Parkinson's disease · 2026 · DOI

• The RNA-seq time course lacked biological replication, - Feature screening was performed before model evaluation and was not nested within each cross-validation fold, - Cross-validation results were interpreted as conditional performance estimates of the locked gene panel rather than as fully unbiased estimates of the entire discovery pipeline

  Multi-omics identification of novel biomarkers and therapeutic targets for Parkinson's disease: from transcriptome to drug interaction · 2026 · DOI

• Further mechanistic and clinical studies are needed to explore the relationship between PD-associated candidate genes and acupuncture-related transcriptomic changes, - Development of personalized therapeutic strategies based on molecular biomarkers associated with acupuncture intervention

  Multi-omics identification of novel biomarkers and therapeutic targets for Parkinson's disease: from transcriptome to drug interaction · 2026 · DOI

• the exact origins and underlying biology of PD remain unclear, - the clinical impact of multi-target MAO-B inhibitors is limited, - several challenges and limitations remain in the development of multi-target MAO-B inhibitors

  Multi-target monoamine oxidase-B (MAO-B) inhibitors in the treatment of Parkinson’s disease · 2025 · DOI

• mitigating exposure to environmental toxicants as a potential strategy for disease prevention, - the development of new treatments for neurodegenerative diseases

  Multi-target monoamine oxidase-B (MAO-B) inhibitors in the treatment of Parkinson’s disease · 2025 · DOI

• Further research is needed to validate the MCID estimates, - Studies using different methodologies and populations could provide additional insights, - Research on the clinical significance of MCID estimates is necessary

  Minimal clinically important differences for treatment of hallucinations in Parkinson’s disease and dementia with Lewy bodies · 2025 · DOI

• Limited understanding of the effects of medicine-food homology compounds on oxidative stress and neurodegeneration. Need for further studies to validate the potential therapeutic benefits of these compounds. Challenges in translating preclinical findings to clinical applications.

  Medicine–food homology bioactives in Parkinson’s disease: multi-target oxidative-stress modulation and translation to dietary supplements · 2025 · DOI

• Evidence is predominantly preclinical, with heterogeneous methods and sparse PD-specific randomized trials - Epidemiologic signals are suggestive but non-causal - There has been a lack of studies exploring lutein's role in PD using molecular mechanistic approaches or mammalian/invertebrate models

  Medicine–food homology bioactives in Parkinson’s disease: multi-target oxidative-stress modulation and translation to dietary supplements · 2025 · DOI

• The relationship between obesity and PD risk remains controversial. Traditional measures, such as BMI, may underestimate neurodegenerative risk by failing to capture visceral fat accumulation. There is a need to evaluate alternative anthropometric indices that reflect central fat deposition.

  Associations between eight anthropometric indices and Parkinson’s disease: a nationwide population-based study · 2025 · DOI

• experimental approaches to target one of the five steps of neurotransmission in a specific region of the nigrostriatal pathway, - determination of if specific changes in DA signaling are driving locomotor impairment

  Dopamine Signaling in Substantia Nigra and Its Impact on Locomotor Function—Not a New Concept, but Neglected Reality · 2024 · DOI

• The neglect of dopamine signaling in the substantia nigra in studies of Parkinson's disease and aging. The lack of understanding of how nigral dopamine signaling impacts locomotor function. The need for an experimental approach to emulate specific mechanisms of DA signaling that exist in vivo in normal or disease states.

  Dopamine Signaling in Substantia Nigra and Its Impact on Locomotor Function—Not a New Concept, but Neglected Reality · 2024 · DOI

• contemplate what type of general or neuron-specific decay mechanisms become more prominent in aged individuals, - investigate the relationship between ROS-induced DNA damage and Parkinson's disease, - study the effects of mitochondrial dysfunction on the viability of dopaminergic neurons

  DNA Damage and Parkinson’s Disease · 2024 · DOI

• The gap in current understanding is the lack of knowledge about the causation of the increase in Parkinson's disease cases. There is a need to contemplate what type of general or neuron-specific decay mechanisms become more prominent in aged individuals. The paper identifies the gap in understanding the relationship between environmental exposures and the development of Parkinson's disease.

  DNA Damage and Parkinson’s Disease · 2024 · DOI

• Issues with cueing devices, including the need for more effective and user-friendly devices. Dataset constraints, including the limited availability of high-quality datasets for freezing of gait research. Ethical and privacy concerns, including the need for secure and private data collection and analysis methods.

  Insights into Parkinson’s Disease-Related Freezing of Gait Detection and Prediction Approaches: A Meta Analysis · 2024 · DOI

• The limited adoption of explainable AI approaches in freezing of gait prediction research represents a significant gap. Current freezing of gait detection and prediction research has limitations, including issues with cueing devices, dataset constraints, ethical and privacy concerns, financial and accessibility restrictions, and the requirement for multidisciplinary collaboration.

  Insights into Parkinson’s Disease-Related Freezing of Gait Detection and Prediction Approaches: A Meta Analysis · 2024 · DOI

• Astrocytes are recognized as active contributors to PD pathogenesis, yet the role of calcineurin (CN), a Ca/calmodulin-dependent phosphatase which is well characterized in neurons, remains unexplored in astrocytes in the context of PD.

  Exosomal miR-23a release coincides with astrocytic calcineurin activation, protects neurons from apoptosis by regulating NOXA in Parkinson's disease models and is enriched in the plasma of patients with Parkinson's disease · 2026 · DOI

• However, lysosomal polygenic risk scores (lyso-PRS) have not been evaluated extensively in PD across populations.

  Lysosomal polygenic risk score in Parkinson's disease across populations. · 2026 · DOI

• Abstract Early hallucination-related phenomena, including minor visual hallucinations (mVHs), are clinically relevant features of Parkinson’s disease (PD), but their neuroanatomical substrates remain unclear.

  Reduced volume of neuromodulatory brainstem nuclei is associated with early hallucination-related vulnerability in Parkinson’s disease · 2026 · DOI

• Because smoking behavior is dynamic, the long-term impact of changes among current smokers remains unclear.

  Dynamic Smoking Patterns and Risk of Parkinson Disease and All-Cause Mortality · 2026 · DOI

Most-cited papers in Parkinson's Disease Mechanisms and Treatments

• α-Synuclein in Lewy bodies · Nature · 1997 · 7,200 citations
• Mutation in the α-Synuclein Gene Identified in Families with Parkinson's Disease · Science · 1997 · 7,161 citations
• Mutations in the parkin gene cause autosomal recessive juvenile parkinsonism · Nature · 1998 · 4,343 citations
• Chronic Parkinsonism in Humans Due to a Product of Meperidine-Analog Synthesis · Science · 1983 · 3,962 citations
• α-Synuclein Locus Triplication Causes Parkinson's Disease · Science · 2003 · 3,859 citations
• Hereditary Early-Onset Parkinson's Disease Caused by Mutations in PINK1 · Science · 2004 · 3,083 citations
• Diagnosis and Treatment of Parkinson Disease · JAMA · 2020 · 2,659 citations
• Pathological α-Synuclein Transmission Initiates Parkinson-like Neurodegeneration in Nontransgenic Mice · Science · 2012 · 2,381 citations
• D 1 and D 2 Dopamine Receptor-regulated Gene Expression of Striatonigral and Striatopallidal Neurons · Science · 1990 · 2,354 citations
• Mutations in the DJ-1 Gene Associated with Autosomal Recessive Early-Onset Parkinsonism · Science · 2003 · 2,351 citations

Most recent work

• CSF α-Synuclein Seed Amplification Assays and Skin Immunofluorescence · Neurology · 2026
• Diagnostic Performance of the α-Synuclein Seed Amplification Assay for Dementia With Lewy Bodies · Neurology · 2026
• Microbiome signature of Parkinson’s disease in healthy and genetically at-risk individuals · Nature Medicine · 2026
• A quantitative DOPA decarboxylase biomarker for diagnosis in Lewy body disorders · Nature Medicine · 2026
• Genetically encoded fluorescent reporters to visualize α-synuclein pathology in live brain · Cell · 2026
• Ultrastructural diversity and subcellular organization of nigral Lewy pathology in Parkinson's disease · bioRxiv · 2026
• Network analysis of α-synuclein pathology progression reveals p21-activated kinases as regulators of vulnerability · bioRxiv · 2026
• Investigation of Disease-Relevant Lysine Acetylation Sites in α-Synuclein Enabled by Non-canonical Amino Acid Mutagenesis · bioRxiv · 2026
• Sex and genotype influence the disruption of circulating NMDAR-related amino acids in patients with Parkinson's disease · medRxiv · 2026
• Parkinson's disease genetics across diverse ancestries: an observational genetic study of causal and risk variants with translational implications · The Lancet Neurology · 2026

Related topics in Medicine