Alpha-synucleinopathy is postulated to be central to both idiopathic rapid eye movement sleep behaviour disorder (iRBD) and Parkinson’s disease (PD). Growing evidence suggests an association between the diminished clearance of α-synuclein and glymphatic system dysfunction. However, evidence accumulating primarily based on clinical data to support glymphatic system dysfunction in patients with iRBD and PD is currently insufficient. This study aimed to use diffusion tensor image analysis along the perivascular space (DTI-ALPS) to evaluate glymphatic system activity and its relationship to clinical scores of disease severity in patients with possible iRBD (piRBDs) and those with PD. Further, we validated the correlation between the ALPS index and the prognosis of PD longitudinally. Overall, 168 patients with PD, 119 piRBDs, and 129 healthy controls were enroled. Among them, 50 patients with PD had been longitudinally reexamined. Patients with PD exhibited a lower ALPS index than those with piRBDs (P = 0.036), and both patient groups showed a lower ALPS index than healthy controls (P < 0.001 andP = 0.001). The ALPS index and elevated disease severity were negatively correlated in the piRBD and PD subgroups. Moreover, the ALPS index was correlated with cognitive decline in patients with PD in the longitudinal analyses. In conclusion, DTI-ALPS provided neuroimaging evidence of glymphatic system dysfunction in piRBDs and patients with PD; however, the potential of assessing the pathological progress of α-synucleinopathies as an indicator is worth verifying. Further development of imaging methods for glymphatic system function is also warranted.
The glymphatic system offers a perivascular pathway for the clearance of pathological proteins and metabolites to optimize neurological functions. Glymphatic dysfunction plays a pathogenic role in Parkinson's disease (PD); however, the molecular mechanism of glymphatic dysfunction in PD remains elusive. To explore whether matrix metalloproteinase-9 (MMP-9)-mediated β-dystroglycan (β-DG) cleavage is involved in the regulation of aquaporin-4 (AQP4) polarity-mediated glymphatic system in PD. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD and A53T mice were used in this study. The glymphatic function was evaluated using ex vivo imaging. TGN-020, an AQP4 antagonist, was administered to investigate the role of AQP4 in glymphatic dysfunction in PD. GM6001, an MMP-9 antagonist, was administered to investigate the role of the MMP-9/β-DG pathway in regulating AQP4. The expression and distribution of AQP4, MMP-9, and β-DG were assessed using western blotting, immunofluorescence, and co-immunoprecipitation. The ultrastructure of basement membrane (BM)-astrocyte endfeet was detected using transmission electron microscopy. Rotarod and open-field tests were performed to evaluate motor behavior. Perivascular influx and efflux of cerebral spinal fluid tracers were reduced in MPTP-induced PD mice with impaired AQP4 polarization. AQP4 inhibition aggravated reactive astrogliosis, glymphatic drainage restriction, and dopaminergic neuronal loss in MPTP-induced PD mice. MMP-9 and cleaved β-DG were upregulated in both MPTP-induced PD and A53T mice, with reduced polarized localization of β-DG and AQP4 to astrocyte endfeet. MMP-9 inhibition restored BM-astrocyte endfeet-AQP4 integrity and attenuated MPTP-induced metabolic perturbations and dopaminergic neuronal loss. AQP4 depolarization contributes to glymphatic dysfunction and aggravates PD pathologies, and MMP-9-mediated β-DG cleavage regulates glymphatic function through AQP4 polarization in PD, which may provide novel insights into the pathogenesis of PD.
23 September 2022 in Journal of Neurology, Neurosurgery & Psychiatry
Background: Abnormal expanded GGC repeats within theNOTCH2HLCgene has been confirmed as the genetic mechanism for most Asian patients with neuronal intranuclear inclusion disease (NIID). This cross-sectional observational study aimed to characterise the clinical features ofNOTCH2NLC-related NIID in China.Methods: Patients withNOTCH2NLC-related NIID underwent an evaluation of clinical symptoms, a neuropsychological assessment, electrophysiological examination, MRI and skin biopsy.Results: In the 247 patients withNOTCH2NLC-related NIID, 149 cases were sporadic, while 98 had a positive family history. The most common manifestations were paroxysmal symptoms (66.8%), autonomic dysfunction (64.0%), movement disorders (50.2%), cognitive impairment (49.4%) and muscle weakness (30.8%). Based on the initial presentation and main symptomology, NIID was divided into four subgroups: dementia dominant (n=94), movement disorder dominant (n=63), paroxysmal symptom dominant (n=61) and muscle weakness dominant (n=29). Clinical (42.7%) and subclinical (49.1%) peripheral neuropathies were common in all types. Typical diffusion-weighted imaging subcortical lace signs were more frequent in patients with dementia (93.9%) and paroxysmal symptoms types (94.9%) than in those with muscle weakness (50.0%) and movement disorders types (86.4%). GGC repeat sizes were negatively correlated with age of onset (r=−0.196, p<0.05), and in the muscle weakness-dominant type (median 155.00), the number of repeats was much higher than in the other three groups (p<0.05). In NIID pedigrees, significant genetic anticipation was observed (p<0.05) without repeat instability (p=0.454) during transmission.Conclusions: NIID is not rare; however, it is usually misdiagnosed as other diseases. Our results help to extend the known clinical spectrum ofNOTCH2NLC-related NIID.
Introduction: China has the most people with Parkinson disease (PD) in the world and is estimated to have over half of the worldwide PD population. The objective of this study was to analyze the corresponding burden of PD in China for the past decades. Method: Data on disease burden related to PD in China were retrieved from the Global Burden of Disease (GBD) 2019 study. The estimated annual percentage changes (EAPCs) were calculated to assess temporal trends, and the ratio of years lived with disability (YLDs) to disability-adjusted life years (DALYs) was used as an index to evaluate the healthcare system. Result: Nationally, the burden of PD increased from 1990 to 2019. Although the age-standardized incidence rate (ASIR) increased, the age-standardized death rate (ASDR) and age-standardized DALY rate both decreased. Age-standardized rates of PD in males remained higher than those in females, but trends in ASDR and the age-standardized DALY rate for females showed a pronounced decrease. The most remarkable increase in the ASIR was in individuals aged 45–49 years, with an EAPC of 1.74 (95% confidence interval, 1.26–2.21). The YLDs:DALYs ratio continuously increased compared with global figures and even with countries with high sociodemographic index (SDI). Conclusion: Although ASDR and age-standardized DALY rates for PD have been declining, the burden of PD still needs attention as the total numbers have increased over the period. Generally, the greater burden of PD was in males. A sound health system with services tailored to PD continues to be required in the future.
22 December 2020 in Journal of Healthcare Engineering
Prompt diagnosis of benign and malignant breast masses is essential for early breast cancer screening. Convolutional neural networks (CNNs) can be used to assist in the classification of benign and malignant breast masses. A persistent problem in current mammography mass classification via CNN is the lack of local-invariant features, which cannot effectively respond to geometric image transformations or changes caused by imaging angles. In this study, a novel model that trains both texton representation and deep CNN representation for mass classification tasks is proposed. Rotation-invariant features provided by the maximum response filter bank are incorporated with the CNN-based classification. The fusion after implementing the reduction approach is used to address the deficiencies of CNN in extracting mass features. This model is tested on public datasets, CBIS-DDSM, and a combined dataset, namely, mini-MIAS and INbreast. The fusion after implementing the reduction approach on the CBIS-DDSM dataset outperforms that of the other models in terms of area under the receiver operating curve (0.97), accuracy (94.30%), and specificity (97.19%). Therefore, our proposed method can be integrated with computer-aided diagnosis systems to achieve precise screening of breast masses.