Anticholinergic Medication Burden in Parkinson's Disease Outpatients

α-Synuclein pathology from the body to the brain: so many seeds so close to the central soil

ABSTRACT

α-Synuclein is a protein that mainly exists in the presynaptic terminals. Abnormal folding and accumulation of α-synuclein are found in several neurodegenerative diseases, including Parkinson's disease. Aggregated and highly phosphorylated α-synuclein constitutes the main component of Lewy bodies in the brain, the pathological hallmark of Parkinson's disease. For decades, much attention has been focused on the accumulation of α-synuclein in the brain parenchyma rather than considering Parkinson's disease as a systemic disease. Recent evidence demonstrates that, at least in some patients, the initial α-synuclein pathology originates in the peripheral organs and spreads to the brain. Injection of α-synuclein preformed fibrils into the gastrointestinal tract triggers the gut-to-brain propagation of α-synuclein pathology. However, whether α-synuclein pathology can occur spontaneously in peripheral organs independent of exogenous α-synuclein preformed fibrils or pathological α-synuclein leakage from the central nervous system remains under investigation. In this review, we aimed to summarize the role of peripheral α-synuclein pathology in the pathogenesis of Parkinson's disease. We also discuss the pathways by which α-synuclein pathology spreads from the body to the brain.

Seizures due to pyridoxine deficiency in Parkinson's disease

Parkinson's disease (PD) is a complex neurodegenerative disorder characterized not only by its hallmark motor symptoms but also by a myriad of non-motor manifestations, including cognitive decline, autonomic manifestations, and gastrointestinal disturbances. Amidst these, a lesser-known but critical aspect is the increased risk of functional deficiency of pyridoxine (vitamin B6) in patients with PD, which is linked to an increased risk of seizures. This review investigates the intersection of PD, new-onset seizures, and pyridoxine deficiency, aiming to elucidate the significance of these associations and their contributions to the neurologic burden in PD. Case reports documenting the occurrence of seizures in patients with PD, particularly in the context of high-dose dopaminergic therapy and the subsequent revelation of pyridoxine deficiency were included. These cases, which often featured extensive workups revealing unremarkable findings aside from pyridoxine deficiency, underscore the multifaceted nature of PD and its treatment-related complications. The findings in these case reports suggest that dietary insufficiencies, gastrointestinal dysfunctions, and drug-nutrient interactions may eventually precipitate pyridoxine deficiency, which in turn may lead to seizures by disrupting GABAergic neurotransmission. This sheds the light on the need for increased clinical awareness and routine monitoring of pyridoxine levels in patients with PD, especially those undergoing significant therapeutic adjustments or exhibiting comorbidities that might interfere with their dietary intake such as gastrointestinal manifestations or depression. Such proactive measures could potentially mitigate the impact of this complication in patients with PD, ultimately enhancing patient care and quality of life.

Prevalence and patterns of the concurrent use of anticholinergics for the motor symptoms of Parkinson's disease and acetylcholinesterase inhibitors in Parkinson's disease patients with dementia: a cross-sectional study using Korea National Health Insurance claims data

BACKGROUND

The concurrent use of anticholinergics and acetylcholinesterase inhibitors (ACHEIs) in Parkinson's disease (PD) patients with dementia should be avoided because the opposing pharmacological actions of both drugs reduce the treatment efficacy. We aimed to investigate the prevalence of the concurrent use of these two types of drugs in Korean patients.

METHODS

In the 2017 Health Insurance Review and Assessment Service-National Aged Patient Sample data, comprising insurance claims records for a 10% random sample of patients aged ≥ 65 years in Korea, "concurrent use" was defined as the overlapping of anticholinergic and ACHEI doses for at least 2 months.

RESULTS

Among 8,845 PD patients with dementia, 847 (9.58%) were co-administered anticholinergics, used to treat the motor symptoms of PD, and ACHEIs for a mean duration of 7.7 months. A total of 286 (33.77% of all co-administered) patients used both drug types concurrently all year. About 80% of concurrent users were prescribed each drug by the same prescriber, indicating that coadministration may not be due to a lack of information sharing between providers. Logistic regression analysis showed that patients mainly treated at clinics (odds ratio (OR), 1.541; 95% confidence interval (CI), 1.158-2.059), hospitals (OR, 2.135; 95% CI, 1.586-2.883), and general hospitals (OR, 1.568; 95% CI, 1.221-2.028) were more likely to be co-prescribed anticholinergics and ACHEIs than those mainly treated at tertiary-care hospitals. PD patients with dementia treated at healthcare organizations located in areas other than the capital city had an approximately 22% higher risk of concurrent use (OR: 1.227, 95% CI: 1.046-1.441).

CONCLUSIONS

The concurrent use of anticholinergics for the motor symptoms of PD and ACHEIs in elderly Korean PD patients with dementia cannot be ignored, and strategies that mitigate potentially inappropriate concurrent drug use are required.

Neuroprotective Effects of Oligosaccharides From Periplaneta Americana on Parkinson’s Disease Models In Vitro and In Vivo

Parkinson’s disease (PD) is one of the neurodegenerative diseases that is characterized by obvious motor and some nonmotor symptoms. Various therapeutics failed in the effective treatment of PD because of impaired neurological function in the brain and various complications. Periplaneta Americana oligosaccharides (OPA), the main active ingredients extracted from the medicine residues of Periplaneta Americana (P. Americana), have been reported to exert anti-inflammatory effects. The purpose of this study was to evaluate the possible mechanisms of OPA against 1-methyl-4-phenylpyridinium (MPP⁺)-induced apotosis in SH-SY5Y cells and its potential neuroprotective effects in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD subacute model mice. The data demonstrated that OPA significantly reversed the MPP⁺-induced decrease in SH-SY5Y cell viability, reduced the proportion of apoptotic cells, and protected SH-SY5Y cells from apoptosis in a dose-dependent manner by regulating the expression of apoptosis-related genes. Furthermore, OPA also alleviated the motor dysfunction of PD model mice, prevented the loss of tyrosine hydroxylase positive cells, suppressed the apoptosis of substantia nigra cells, and improved the dysbiosis of gut microbiota in vivo, suggesting that OPA demonstrated a significantly neuroprotective effect on PD model mice. These results indicated that OPA might be the possibility of PD therapeutics with economic utility and high safety.