Pure autonomic failure: a case report / 中华神经科杂志

Pure autonomic failure (PAF) is an α-synucleinopathy featured by slowly progressive autonomic failure. A patient who presented with orthostatic hypotension associated dizziness and syncope, postprandial hypotension, supine hypertension and anhidrosis, was hospitalized. The patient did not show incontinence, urinary retention, constipation, ataxia, and extrapyramidal symptoms. In combination of the description of the patient′s symptoms with PAF related references, the pathogenesis, clinical manifestations, diagnosis and differential diagnosis of PAF and its relationship with other α-synucleinopathies were demonstrated in this report.

Targeting Microglial and Neuronal Toll-like Receptor 2 in Synucleinopathies

Synucleinopathies are neurodegenerative disorders characterized by the progressive accumulation of α-synuclein (α-syn) in neurons and glia and include Parkinson's disease (PD) and dementia with Lewy bodies (DLB). In this review, we consolidate our key findings and recent studies concerning the role of Toll-like receptor 2 (TLR2), a pattern recognition innate immune receptor, in the pathogenesis of synucleinopathies. First, we address the pathological interaction of α-syn with microglial TLR2 and its neurotoxic inflammatory effects. Then, we show that neuronal TLR2 activation not only induces abnormal α-syn accumulation by impairing autophagy, but also modulates α-syn transmission. Finally, we demonstrate that administration of a TLR2 functional inhibitor improves the neuropathology and behavioral deficits of a synucleinopathy mouse model. Altogether, we present TLR2 modulation as a promising immunotherapy for synucleinopathies.

The Prevalence of Cerebral Microbleeds in Non-Demented Parkinson's Disease Patients

BACKGROUND: Cerebral microbleeds (CMBs) are associated with cerebrovascular risk factors and cognitive dysfunction among patients with Parkinson's disease (PD). However, whether CMBs themselves are associated with PD is to be elucidated. METHODS: We analyzed the presence of CMBs using 3-Tesla brain magnetic resonance imaging in non-demented patients with PD and in age-, sex-, and hypertension-matched control subjects. PD patients were classified according to their motor subtypes: tremor-dominant, intermediate, and postural instability-gait disturbance (PIGD). Other cerebrovascular risk factors and small vessel disease (SVD) burdens were also evaluated. RESULTS: Two-hundred and five patients with PD and 205 control subjects were included. The prevalence of CMBs was higher in PD patients than in controls (16.1% vs. 8.8%; odds ratio [OR], 2.126; P = 0.019); CMBs in the lobar area showed a significant difference between PD patients and controls (11.7% vs. 5.9%; OR, 2.234; P = 0.032). According to the motor subtype, CMBs in those with PIGD type showed significant difference from controls with respect to the overall brain area (21.1% vs. 8.9%; OR, 2.759; P = 0.010) and lobar area (14.6% vs. 4.9%; OR, 3.336; P = 0.016). Among PD patients, those with CMBs had higher age and more evidence of SVDs than those without CMBs. CONCLUSION: We found that CMBs are more frequent in PD patients than in controls, especially in those with the PIGD subtype and CMBs on the lobar area. Further study investigating the pathogenetic significance of CMBs is required.

Mechanism of Anti-α-Synuclein Immunotherapy

Immunization therapy targeting α-synuclein has emerged as a promising approach for Parkinson's disease and perhaps for other synucleinopathies. Several antibodies have shown therapeutic effects in mouse models of synucleinopathies and have alleviated the pathological and behavioral phenotypes of these mice. The mechanisms through which the immunization therapy works were initially puzzling, especially given that α-synuclein is a typical cytosolic protein. Recent studies, however, suggested that extracellular α-synuclein is an important pathogenic entity, and hence, a target for immunotherapy. Here, we review the literature describing immunization therapy for synucleinopathies in mouse models and provide current thoughts on the potential mechanisms underlying the therapeutic effects of α-synuclein immunotherapy.

Alpha-Synuclein Function and Dysfunction on Cellular Membranes

Alpha-synuclein is a small neuronal protein that is closely associated with the etiology of Parkinson's disease. Mutations in and alterations in expression levels of alpha-synuclein cause autosomal dominant early onset heredity forms of Parkinson's disease, and sporadic Parkinson's disease is defined in part by the presence of Lewy bodies and Lewy neurites that are composed primarily of alpha-synuclein deposited in an aggregated amyloid fibril state. The normal function of alpha-synuclein is poorly understood, and the precise mechanisms by which it leads to toxicity and cell death are also unclear. Although alpha-synuclein is a highly soluble, cytoplasmic protein, it binds to a variety of cellular membranes of different properties and compositions. These interactions are considered critical for at least some normal functions of alpha-synuclein, and may well play critical roles in both the aggregation of the protein and its mechanisms of toxicity. Here we review the known features of alpha-synuclein membrane interactions in the context of both the putative functions of the protein and of its pathological roles in disease.

LRRK2 as a Potential Genetic Modifier of Synucleinopathies: Interlacing the Two Major Genetic Factors of Parkinson's Disease

Parkinson's disease (PD) and related Lewy body diseases are characterized by deposition of alpha-synuclein aggregates in both the central nervous system and peripheral nervous system. Synucleinopathy lesions spread to larger brain areas as the disease progresses, and prion-like cell-to-cell transmission of aggregated alpha-synuclein is thought to be the underlying mechanism for this pathological spreading. LRRK2 is another protein linked to the pathogenesis of PD, and its presence in Lewy bodies has attracted much attention as to whether LRRK2 and alpha-synuclein interplay during the pathogenesis of PD. However, the relationship between these two crucial proteins still remains unclear. In this review article, we will discuss the current state of knowledge in terms of how these proteins cause the disease and provide the hypothetical mechanisms by which LRRK2 might modify the generation and progression of synucleinopathy.

Rapid eye movement sleep behavior disorder as a predicting phenomenon of ?-synucleinopathies(report of 1 case) / 临床神经病学杂志

Objective To improve the recognition of rapid eye movement(REM) sleep behavior disorder(RBD) as an early marker for ?-synucleinopathies.Methods By studying a typical case of RBD followed with multiple system atrophy-P,the clinical features,pathogenesis and its correlation with ?-synucleinopathies of RBD were elucidated.Results This case manifested a serial of paroxysmal increased activities of the limbs and behavioral disturbances during his REM sleep,and parkinsonism features appeared 9 years later.His cranial MRI showed the abnormal long T1 and T2 signals at bilateral centrum ovale,corona radiate and basal ganglia area of the cerebral hemisphere.Conclusions RBD is clinically characterized with paroxysmal behavioral disorder in the REM sleep,the changes of the brain stem,striatum and cortical perfusion are attributed to the RBD pathogenesis.Closely linked to a-synucleinopathies,RBD may be clinical harbinger of those disorders.