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Current Opinion in Neurology Aug 2023The purpose is to review the results and impact of recent studies for current and future treatment of both motor and non-motor symptoms in Parkinson's disease (PD). (Review)
Review
PURPOSE OF REVIEW
The purpose is to review the results and impact of recent studies for current and future treatment of both motor and non-motor symptoms in Parkinson's disease (PD).
RECENT FINDINGS
New formulations of levodopa further optimize motor fluctuations, allowing for more on-time and less dyskinesia. On demand apomorphine continues to showcase itself as an effective and tolerable tool for treating motor off-periods. Though there are no clear treatment guidelines for PD-related constipation and sleep related disorders, several new agents for these non-motor symptoms show promising preliminary data. Expiratory muscle strength training may represent a useful and cost-effective strategy to alleviate oropharyngeal dysphagia associated with PD. There is evidence to suggest that the use of shorter pulse width and directional deep brain stimulation leads can results in a greater therapeutic window.
SUMMARY
Though no interventions currently exist to significantly modify the disease progression of PD, new studies continue to give insight into optimal symptomatic management. Clinicians should be familiar with expanding the repertoire of tools available to treat the diverse range of symptoms and challenges associated with PD.
Topics: Humans; Parkinson Disease; Antiparkinson Agents; Levodopa; Dyskinesias; Disease Progression
PubMed: 37366218
DOI: 10.1097/WCO.0000000000001166 -
Cell Nov 2023Parkinson's disease (PD) is a debilitating neurodegenerative disorder. Its symptoms are typically treated with levodopa or dopamine receptor agonists, but its action...
Parkinson's disease (PD) is a debilitating neurodegenerative disorder. Its symptoms are typically treated with levodopa or dopamine receptor agonists, but its action lacks specificity due to the wide distribution of dopamine receptors in the central nervous system and periphery. Here, we report the development of a gene therapy strategy to selectively manipulate PD-affected circuitry. Targeting striatal D1 medium spiny neurons (MSNs), whose activity is chronically suppressed in PD, we engineered a therapeutic strategy comprised of a highly efficient retrograde adeno-associated virus (AAV), promoter elements with strong D1-MSN activity, and a chemogenetic effector to enable precise D1-MSN activation after systemic ligand administration. Application of this therapeutic approach rescues locomotion, tremor, and motor skill defects in both mouse and primate models of PD, supporting the feasibility of targeted circuit modulation tools for the treatment of PD in humans.
Topics: Animals; Humans; Mice; Corpus Striatum; Genetic Therapy; Levodopa; Neurons; Parkinson Disease; Primates; Receptors, Dopamine D1; Disease Models, Animal
PubMed: 37922901
DOI: 10.1016/j.cell.2023.10.004 -
Journal of Neural Transmission (Vienna,... Nov 2023Advanced Parkinson's disease is characterized by periods of poor mobility, dyskinesia and progressive decline in functional independence of the affected person despite... (Review)
Review
Advanced Parkinson's disease is characterized by periods of poor mobility, dyskinesia and progressive decline in functional independence of the affected person despite the manipulation of levodopa doses and the introduction of supplemental therapies such as catechol-O-methyl transferase inhibitors, monoamine oxidase-B inhibitors and dopamine agonists. The implementation of drug delivery systems allows to bypass problems related to irregular and often unpredictable intestinal absorption of oral levodopa, which significantly affects its bioavailability and contributes to the development and persistence of motor complications. Subcutaneous apomorphine and levodopa/carbidopa jejunal infusion systems have been available for many years and their efficacy is confirmed by randomized studies and long-term experience in many centers worldwide. Recently, a new formulation of levodopa/carbidopa infusion gel that includes the catechol-O-methyl transferase inhibitor Entacapone has been introduced to the market. The use of entacapone allows to reduce total daily dose of administered levodopa. Two different soluble formulations of levodopa/carbidopa (ND0612 and ABBV-951) have completed clinical development, and both can ensure subcutaneous delivery by a portable pump infusion system. ABBV-951 uses a foslevodopa/foscarbidopa formulation, both prodrugs to improve absorption and tolerability. Both systems provide effective improvement of motor complications and are likely to expand the therapeutic options in advanced patients. Future efforts should focus on the earlier detection of patients who are candidates for device-aided therapies, increasing appropriate referral and broadening the availability of these treatments globally.
Topics: Humans; Parkinson Disease; Levodopa; Carbidopa; Antiparkinson Agents; Catechol O-Methyltransferase; Catechols; Dopamine Agonists; Drug Combinations
PubMed: 37672049
DOI: 10.1007/s00702-023-02693-8 -
Medicina (Kaunas, Lithuania) Aug 2023Depression represents one of the most common non-motor disorders in Parkinson's disease (PD) and it has been related to worse life quality, higher levels of disability,... (Review)
Review
Depression represents one of the most common non-motor disorders in Parkinson's disease (PD) and it has been related to worse life quality, higher levels of disability, and cognitive impairment, thereby majorly affecting not only the patients but also their caregivers. Available pharmacological therapeutic options for depression in PD mainly include selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, and tricyclic antidepressants; meanwhile, agents acting on dopaminergic pathways used for motor symptoms, such as levodopa, dopaminergic agonists, and monoamine oxidase B (MAO-B) inhibitors, may also provide beneficial antidepressant effects. Recently, there is a growing interest in non-pharmacological interventions, including cognitive behavioral therapy; physical exercise, including dance and mind-body exercises, such as yoga, tai chi, and qigong; acupuncture; therapeutic massage; music therapy; active therapy; repetitive transcranial magnetic stimulation (rTMS); and electroconvulsive therapy (ECT) for refractory cases. However, the optimal treatment approach for PD depression is uncertain, its management may be challenging, and definite guidelines are also lacking. It is still unclear which of these interventions is the most appropriate and for which PD stage under which circumstances. Herein, we aim to provide an updated comprehensive review of both pharmacological and non-pharmacological treatments for depression in PD, focusing on recent clinical trials, systematic reviews, and meta-analyses. Finally, we discuss the pharmacological agents that are currently under investigation at a clinical level, as well as future approaches based on the pathophysiological mechanisms underlying the onset of depression in PD.
Topics: Humans; Parkinson Disease; Depression; Levodopa; Acupuncture Therapy; Antidepressive Agents, Tricyclic
PubMed: 37629744
DOI: 10.3390/medicina59081454 -
Movement Disorders : Official Journal... Jul 2023To compare drug regimens across clinical trials in Parkinson's disease (PD) conversion formulae between antiparkinsonian drugs have been developed. These are reported in...
BACKGROUND
To compare drug regimens across clinical trials in Parkinson's disease (PD) conversion formulae between antiparkinsonian drugs have been developed. These are reported in relation to levodopa as the benchmark drug in PD pharmacotherapy as 'levodopa equivalent dose' (LED). Currently, the LED conversion formulae proposed in 2010 by Tomlinson et al. based on a systematic review are predominantly used. However, new drugs with established and novel mechanisms of action and novel formulations of longstanding drugs have been developed since 2010. Therefore, consensus proposals for updated LED conversion formulae are needed.
OBJECTIVES
To update LED conversion formulae based on a systematic review.
METHODS
The MEDLINE, CENTRAL, and Embase databases were searched from January 2010 to July 2021. Additionally, in a standardized process according to the GRADE grid method, consensus proposals were issued for drugs with scarce data on levodopa dose equivalency.
RESULTS
The systematic database search yielded 3076 articles of which 682 were eligible for inclusion in the systematic review. Based on these data and the standardized consensus process, we present proposals for LED conversion formulae for a wide range of drugs that are currently available for the pharmacotherapy of PD or are expected to be introduced soon.
CONCLUSIONS
The LED conversion formulae issued in this Position Paper will serve as a research tool to compare the equivalence of antiparkinsonian medication across PD study cohorts and facilitate research on the clinical efficacy of pharmacological and surgical treatments as well as other non-pharmacological interventions in PD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Topics: Humans; Levodopa; Parkinson Disease; Antiparkinson Agents; Treatment Outcome
PubMed: 37147135
DOI: 10.1002/mds.29410 -
CNS & Neurological Disorders Drug... 2024Currently, available therapeutics for the treatment of Parkinson's disease (PD) fail to provide sustained and predictable relief from motor symptoms without significant... (Review)
Review
Currently, available therapeutics for the treatment of Parkinson's disease (PD) fail to provide sustained and predictable relief from motor symptoms without significant risk of adverse events (AEs). While dopaminergic agents, particularly levodopa, may initially provide strong motor control, this efficacy can vary with disease progression. Patients may suffer from motor fluctuations, including sudden and unpredictable drop-offs in efficacy. Dopamine agonists (DAs) are often prescribed during early-stage PD with the expectation they will delay the development of levodopa-associated complications, but currently available DAs are less effective than levodopa for the treatment of motor symptoms. Furthermore, both levodopa and DAs are associated with a significant risk of AEs, many of which can be linked to strong, repeated stimulation of D2/D3 dopamine receptors. Targeting D1/D5 dopamine receptors has been hypothesized to produce strong motor benefits with a reduced risk of D2/D3-related AEs, but the development of D1-selective agonists has been previously hindered by intolerable cardiovascular AEs and poor pharmacokinetic properties. There is therefore an unmet need in PD treatment for therapeutics that provide sustained and predictable efficacy, with strong relief from motor symptoms and reduced risk of AEs. Partial agonism at D1/D5 has shown promise for providing relief from motor symptoms, potentially without the AEs associated with D2/D3-selective DAs and full D1/D5-selective DAs. Tavapadon is a novel oral partial agonist that is highly selective at D1/D5 receptors and could meet these criteria. This review summarizes currently available evidence of tavapadon's therapeutic potential for the treatment of early through advanced PD.
Topics: Humans; Dopamine Agonists; Parkinson Disease; Levodopa; Dopamine Agents; Receptors, Dopamine D2; Receptors, Dopamine D1; Antiparkinson Agents
PubMed: 36999711
DOI: 10.2174/1871527322666230331121028 -
Journal of Controlled Release :... Aug 2023Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) resulting in... (Review)
Review
Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) resulting in dopamine (DA) deficiency, which manifests itself in motor symptoms including tremors, rigidity and bradykinesia. Current PD treatments aim at symptom reduction through oral delivery of levodopa (L-DOPA), a precursor of DA. However, L-DOPA delivery to the brain is inefficient and increased dosages are required as the disease progresses, resulting in serious side effects like dyskinesias. To improve PD treatment efficacy and to reduce side effects, recent research focuses on the encapsulation of L-DOPA into polymeric- and lipid-based nanoparticles (NPs). These formulations can protect L-DOPA from systemic decarboxylation into DA and improve L-DOPA delivery to the central nervous system. Additionally, NPs can be modified with proteins, peptides and antibodies specifically targeting the blood-brain barrier (BBB), thereby reducing required dosages and free systemic DA. Alternative delivery approaches for NP-encapsulated L-DOPA include intravenous (IV) administration, transdermal delivery using adhesive patches and direct intranasal administration, facilitating increased therapeutic DA concentrations in the brain. This review provides an overview of the recent advances for NP-mediated L-DOPA delivery to the brain, and debates challenges and future perspectives on the field.
Topics: Humans; Levodopa; Parkinson Disease; Dopamine; Brain; Nanoparticles
PubMed: 37343725
DOI: 10.1016/j.jconrel.2023.06.026 -
Scientific Reports Oct 2023Dopamine transmission has been implicated in motor and cognitive function. In Parkinson's disease (PD), dopamine replacement using the precursor drug L-DOPA is the... (Meta-Analysis)
Meta-Analysis
Dopamine transmission has been implicated in motor and cognitive function. In Parkinson's disease (PD), dopamine replacement using the precursor drug L-DOPA is the predominant treatment approach, but long-term exposure leads to the onset of dyskinesias (LIDs). Chronic L-DOPA exposure has been associated with changes in gene expression and altered cortico-striatal plasticity. The aim of this research was to assess the functional consequence of long-term L-DOPA exposure on cognitive and motor function using a rodent model of PD. Across two independent experiments, we assessed the impact of chronic L-DOPA exposure, or a control DR agonist, on motor and cognitive function in intact and in hemi parkinsonian rats, in the absence of drug. Abnormal involuntary movements associated with LID were measured and brain tissues were subsequently harvested for immunohistochemical analysis. Exposure to chronic L-DOPA, but not the DR agonist, impaired motor and cognitive function, when animals were tested in the absence of drug. A meta-analysis of the two experiments allowed further dissociation of L-DOPA -treated rats into those that developed LIDs (dyskinetic) and those that did not develop LIDs (non-dyskinetic). This analysis revealed impaired cognitive and motor performance were evident only in dyskinetic, but not in non-dyskinetic, rats. These data reveal a functional consequence of the altered plasticity associated with LID onset and have implications for understanding symptom progression in the clinic.
Topics: Rats; Animals; Levodopa; Parkinson Disease; Dopamine; Rats, Sprague-Dawley; Oxidopamine; Dyskinesia, Drug-Induced; Corpus Striatum; Cognition; Disease Models, Animal
PubMed: 37848479
DOI: 10.1038/s41598-023-44869-y -
CNS Neuroscience & Therapeutics Feb 2024Homocysteine (Hcy) is an important metabolite in methionine metabolism. When the metabolic pathway of homocysteine is abnormal, it will accumulate in the body and... (Review)
Review
Homocysteine (Hcy) is an important metabolite in methionine metabolism. When the metabolic pathway of homocysteine is abnormal, it will accumulate in the body and eventually lead to hyperhomocysteinemia. In recent years, many studies have found that hyperhomocysteinemia is related to the occurrence and development of Parkinson's disease. This study reviews the roles of homocysteine in the pathogenesis of Parkinson's disease and illustrates the harmful effects of hyperhomocysteinemia on Parkinson's disease.
Topics: Humans; Parkinson Disease; Levodopa; Hyperhomocysteinemia; Homocysteine
PubMed: 37641911
DOI: 10.1111/cns.14420