ReviewNPJ Parkinson's disease2022
Mechanisms of peripheral levodopa resistance in Parkinson's disease.
Review in NPJ Parkinson's disease, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 61 papers, 3 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
61 citing papers in PubMed, 3 syntheses or guidelines pooled it, 106 citations in OpenAlex.
- Homogenous Cell Transplantation Trials in Parkinson's Disease: A Systematic Review and Meta-Analysis.Movement disorders clinical practice · 2026Pooled it
- Detection of parkinson's disease with neuroimaging modalities using machine learning and artificial intelligence: a systematic review.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2026Pooled it
- Effects of Safinamide on Motor and Non-Motor Symptoms in Patients with Parkinson's Disease and Motor Fluctuations.European neurology · 2024Pooled it
- Implantable Neuromodulation Devices in Psychiatry: Human Fidelity and Implementation Challenges.The American journal of psychiatry · 2026Article
- On-demand therapies-emergency medication or daily routine?Journal of neural transmission (Vienna, Austria : 1996) · 2026Review
- Interface geometry governs probe insertion mechanics and electrode deviation in layered brain-mimicking phantoms for deep brain stimulation.Biomechanics and modeling in mechanobiology · 2026Article
- Pharmacological activation of dopamine receptor D1 attenuates TGF-β-induced epithelial-mesenchymal transition in A549 and BEAS-2B cells.Naunyn-Schmiedeberg's archives of pharmacology · 2026Article
- Serum aromatic l-amino acid decarboxylase activity as a biomarker for prodromal and manifest Parkinson's disease.EBioMedicine · 2026Article
- Advancing the Treatment of Motor Fluctuations in Parkinson's Disease with a Next-Generation Levodopa/Carbidopa Formulation.Neurology and therapy · 2026Review
- A drug-microbiome-drug interaction impacts co-prescribed medications for Parkinson's disease.Nature microbiology · 2026Article
- Neurotransmitter Dysregulation in Parkinson's Disease: Pathophysiological Insights and Therapeutic Perspectives.ACS chemical neuroscience · 2026Review
- Ayurvedic Therapeutic Regimen as an Add-On to Optimized Conventional Management of Parkinson Disease: Protocol for an Exploratory Randomized Controlled Trial Evaluating Clinical, Cortical Excitability, Neuroimmune, and Autonomic Function Parameters.JMIR research protocols · 2026Article
- Differentiating between the impact of sex and gender in Parkinson's disease: utilising these to advance current understanding and care practices.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2026Review
- Local field potential biomarkers for adaptive deep brain stimulation in Parkinson's disease: A scoping review.Surgical neurology international · 2026Review
- Organosulfur Compounds: Potential Therapeutics for Parkinson's Disease.CNS & neurological disorders drug targets · 2026Review
- Levodopa and the dopamine receptor D1-Hippo/yes-associated protein axis: A novel therapeutic avenue for liver fibrosis.World journal of gastroenterology · 2025Article
- Beyond Dysphagia in Parkinson's Disease: 3D Printing of Orally Disintegrating Tablets (ODTs) for Optimized Treatment.Pharmaceuticals (Basel, Switzerland) · 2025Review
- The role of gut microbiota tyrosine decarboxylases in levodopa pharmacokinetics: insights from a levodopa challenge test.BMC neurology · 2025Article
- Interpretable Machine Learning for Cross-Cohort Prediction of Motor Fluctuations in Parkinson's Disease.Movement disorders : official journal of the Movement Disorder Society · 2025Article
- Enhanced catalytic stability for L-Dopa synthesis through cross-linking of Al₂O₃ nanocrystals with Bacillus subtilis tyrosine hydroxylase.World journal of microbiology & biotechnology · 2025Article
1 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Parkinson's disease (PD) is an increasingly common neurodegenerative condition. The disease has a significant negative impact on quality of life, but a personalized management approach can help reduce disability. Pharmacotherapy with levodopa remains the cornerstone of treatment, and a gratifying and sustained response to this treatment is a supportive criterion that argues in favor of an underlying diagnosis of PD. Yet, in daily practice, it is not uncommon to encounter patients who appear to have true PD, but who nevertheless seem to lose the responsiveness to levodopa (secondary non-responders). Some patients may even fail to respond altogether (primary non-responders). Here, we address how two mechanisms of "peripheral resistance" may underlie this failing response to levodopa in persons with PD. The first explanation relates to impaired bowel motility leading to secondary bacterial overgrowth, and more specifically, to the excessive bacterial production of the enzyme tyrosine decarboxylase (TDC). This enzyme may convert levodopa to dopamine in the gut, thereby hampering entry into the circulation and, subsequently, into the brain. The second explanation relates to the systemic induction of the enzyme aromatic L-amino acid decarboxylase (AADC), leading to premature conversion of levodopa into dopamine, again limiting the bioavailability within the brain. We discuss these two mechanisms and focus on the clinical implications, potential treatments and directions for future research.
Identifiers
What Socratic holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.