Summary: Researchers have found that Parkinson’s disease (PD) patients with sympathetic denervation of the major salivary glands and heart have more severe non-motor symptoms as they age.
This research highlights the importance of age in the progression of PD and could improve understanding of the pathophysiology of the disease.
Key fact:
- Non-motor symptoms: Elderly PD patients with sympathetic denervation present with severe olfactory dysfunction, REM sleep behavior disorder, and autonomic nervous system dysfunction.
- MIBG scintigraphy: The study used a quantitative method to analyze MIBG uptake, showing a correlation between denervation and symptom severity.
- Age factor: Age has a significant impact on the progression of non-motor symptoms of PD, independent of cognitive function and disease duration.
Source: Toho University
Dr. Junya Ebina and Professor Osamu Kano from the Department of Neurology, Toho University School of Medicine, together with Professor Sunao Mizumura from the Department of Radiology, reported that patients with Parkinson’s disease (PD) showed sympathetic denervation in the major salivary glands and the heart tends to have more advanced non-motor symptoms as it ages, suggesting that age plays an important role in disease progression.
This research result could potentially contribute to a better understanding of the pathophysiological progression of PD.
This study was posted online on February 12, 2024 and was published in article 122932, volume 458 of Journal of Neurological Sciences, on March 15, 2024.
Key points:
- PD patients with sympathetic denervation of the major salivary glands and heart, as indicated by MIBG scintigraphy (Note 1), are older and have more severe non-motor symptoms, such as olfactory dysfunction, behavioral disturbance in REM sleep and autonomic nervous system dysfunction, according to questionnaire scores, compared to the groups with simple sympathetic denervation or non-sympathetic denervation (Table and Figure). However, cognitive function, disease duration, and MDS-UPDRS motor symptom scores were comparable between groups.
- In this study, a semi-automatic quantitative method developed by the research group last year was used to analyze the absorption of MIBG in the major salivary glands and the heart. This comparative study of clinical symptoms focused on peripheral organs in PD patients, as highlighted by Ebina J et al. J Neurol 2023, could offer a new perspective on disease progression.
- This study may contribute to understanding the pathophysiological progression of PD, leading to more accurate staging of PD and enabling tailored medical care based on each patient’s condition. The research group is also examining the usefulness of new, complementary diagnostic methods.
Presentation overview:
PD is a progressive neurodegenerative disease characterized by abnormal aggregates of α-synuclein called Lewy bodies. Lewy bodies are not only found in the central nervous system but also in peripheral organs.
In PD, cardiac sympathetic denervation detected by 123Myocardial scintigraphy with I-metaiodobenzylguanidine (MIBG) is associated with the presence of Lewy bodies. Conversely, although Lewy bodies are frequently found in the digestive tract, including in the major salivary glands, the process of pathophysiological progression into peripheral organs remains unclear.
A research group previously reported sympathetic denervation in the submandibular and parotid glands of PD patients. Therefore, in this study, they hypothesized and tested whether patients with PD and sympathetic nerve dysfunction in the heart and major salivary glands had more advanced clinical symptoms.
PD patients with sympathetic denervation in the main salivary glands and cardiac areas (double SD group) were found to be older, had more severe olfactory dysfunction and a higher likelihood of REM sleep behavior disorders and severe autonomic nerve dysfunction compared to single SD group or non-SD group.
However, disease duration and cognitive function were similar between groups. Logistic regression analysis with age, sex, and disease duration as variables showed that age was an important factor affecting clinical assessment items in disease progression.
In conclusion, patients with PD and decreased MIBG uptake in major salivary glands and cardiac areas showed progression of symptoms centered on non-motor symptoms, suggesting that autonomic nerve dysfunction may progress independently of nigrostriatal dopaminergic degeneration.
Furthermore, the potential contribution of age to the pathophysiological progression of PD has been suggested. This study may help to understand the pathophysiological progression of PD and can be used for future staging of individual patients.
About this Parkinson’s research news
Author: Akira Muto
Source: Toho University
Contact: Akira Muto – Toho University
Picture: Image is credited to Neuroscience News
Original research: Free access.
“Clinical characteristics of Parkinson’s disease patients with reduced absorption of 123I-metaiodobenzylguanidine in the major salivary glands and heart” by Junya Ebina et al. Journal of Neurological Sciences
Abstract
Clinical characteristics of Parkinson’s disease patients with reduced absorption of 123I-metaiodobenzylguanidine in the major salivary glands and heart
Strong points
- Uptake of MIBG into the major salivary glands is reduced in Parkinson’s disease.
- Parkinson’s disease with reduced MIBG dual absorption presents with advanced non-motor symptoms.
- Autonomic dysfunction can progress independently of dopaminergic degeneration.
- Aging is a crucial factor in Parkinson’s disease.
Abstract
Background
Parkinson’s disease (PD) exhibits cardiac sympathetic denervation (SD) in 123I-metaiodobezylguanidine (MIBG) scintigraphy. Recently, SD in the major salivary glands (MSG-SD) was introduced as a possible radiological feature of PD.
Objective
To identify the clinical characteristics of PD patients with reduced uptake of MSG and cardiac MIBG (double-SD) compared to those with reduced uptake of MSG or cardiac MIBG only (single-SD).
Methods
We recruited 90 PD patients and 30 controls and assessed their non-motor (e.g., hyposmia, autonomic dysfunction) and motor (e.g., Movement Disorder Society-Unified Parkinson’s Disease Rating Scale) characteristics. We also assessed MIBG uptake in MSG and heart using a semi-automated quantitative method, and compared MIBG uptakes between PD and controls. We set cutoff values for optimal sensitivity and specificity, and compared the clinical characteristics of PD patients between the double and single SD groups.
Results
Cardiac MSG and MIBG uptakes were significantly reduced in PD. Sixty-one patients had double SD, 25 had simple SD and four had non-SD. In PD patients with normal cardiac SD, 76.5% (13/17) had abnormalities only in MSG-SD. When clinical characteristics were compared between the double SD and single/non-SD groups, patients in the double SD group were older and had more severe hyposmia and autonomic dysfunction, except for motor characteristics. Multiple logistic regression analysis identified age as a significant confounder.
Conclusions
PD patients with double SD present more severe non-motor features than other patients. Autonomic dysfunction can progress independently of dopaminergic degeneration. Furthermore, our results indicate that aging is a crucial factor in the progression of PD.