alpha-synuclein and Hypotension--Orthostatic

Parkinson's disease, dementia with Lewy bodies and multiple system atrophy are characterised by abnormal neuroglial α-synuclein accumulation. These α-synucleinopathies have in common parkinsonism and non-motor features including orthostatic hypotension (OH) and cognitive impairment. However, the nature of the relationship between OH and cognitive impairment is unclear. We therefore systematically reviewed the literature for evidence of an association between OH and cognitive impairment in α-synucleinopathies and discuss possible mechanisms and implications of this relationship. Abstracts from 313 original research articles were surveyed, and a total of 132 articles were considered for this review. Articles were stratified as: 'direct-evidence studies' based on the direct assessment for a relationship between OH and cognitive impairment in α-synucleinopathies, and 'indirect-evidence studies' based on an association being referred to as a secondary outcome. Ten 'direct-evidence papers' were identified, seven of which reported a positive association between OH and cognitive impairment, while seven of 12 'indirect-evidence papers' similarly did as well. The papers that reported no association between OH and cognitive impairment used less sensitive measures of cognition. A relationship between OH and cognitive impairment in patients with α-synucleinopathies exists, but the underlying mechanisms remain unclear. Three hypotheses are proposed: (1) OH and cognitive impairment occur concurrently due to diffuse brain and peripheral deposition of α-synuclein, (2) OH-mediated cerebral hypoperfusion impairs cognition and (3) the two act synergistically to accelerate cognitive decline. Longitudinal neuroimaging studies and clinical trials may help clarify the nature of this relationship.

Topics: alpha-Synuclein; Cerebral Small Vessel Diseases; Cognitive Dysfunction; Humans; Hypotension, Orthostatic; Hypoxia-Ischemia, Brain; Lewy Body Disease; Longitudinal Studies; Magnetic Resonance Imaging; Mental Status Schedule; Multiple System Atrophy; Neuroglia; Parkinson Disease; Positron Emission Tomography Computed Tomography; Risk Factors; Statistics as Topic

Cardiovascular autonomic failure is the second most common dysautonomic feature of α-synucleinopathies and has significant impact on daily activities and quality of life. Here we provide a systematic review of cardiovascular autonomic failure in α-synucleinopathies, emphasizing its impact on cognitive functions and disease outcomes. Articles spanning the period between January 1985 and April 2012 were identified from the PubMed database using a keyword-based search. Epidemiological studies highlight the negative prognostic effect of cardiovascular autonomic failure on cardiovascular and cerebrovascular outcomes and overall mortality in all α-synucleinopathies. Altered cerebral perfusion, vascular pressure stress, and related disruption of the blood-brain barrier may also contribute to the white matter hyperintensities and cognitive dysfunction frequently found in patients affected by neurocardiovascular instability. These findings support the hypothesis that cardiovascular autonomic failure may play a negative prognostic role in α-synucleinopathies and suggest that precocious screening and therapeutic management of cardiovascular autonomic failure may positively impact disease course.

Topics: alpha-Synuclein; Brain; Cardiovascular System; Cognition Disorders; Disease Progression; Fatigue; Humans; Hypotension, Orthostatic; Lewy Body Disease; Multiple System Atrophy; Neurodegenerative Diseases; Parkinson Disease; Primary Dysautonomias; Prognosis; Pure Autonomic Failure

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia in older people that has only been recognized in the past decade and that remains widely underdiagnosed. At postmortem examination, affected patients show numerous alpha-synuclein-positive Lewy bodies (LB) in many parts of the cerebral cortex, particularly neocortical and limbic areas in addition to the nigral LB degeneration characteristic of Parkinson's disease (PD). Clinical presentation, unlike PD, is with progressive cognitive decline with particular deficits of visuospatial ability as well as frontal executive function accompanied by usually only mildly to moderately severe parkinsonism, which is often akineto-rigid without the classical parkinsonian rest-tremor. Further accompanying features include spontaneous recurrent visual hallucinations and conspicuous fluctuations in alertness and cognitive performance. The two main differential diagnoses are Alzheimer's disease (AD) and Parkinson's disease dementia (PDD). To improve the differential diagnosis of DLB, consensus criteria have been developed that establish possible and probable levels of clinical diagnostic accuracy. Generally, their sensitivity is variable and low but their specificity is high. Current consensus is to restrict a diagnosis of DLB only to patients with parkinsonism who develop dementia within 12 months of the onset of motor symptoms. Using operationalized criteria, DLB can be diagnosed clinically with an accuracy similar to that achieved for AD or PD. Ancillary investigations, particularly neuroimaging, can aid in differential diagnosis. We review the present state of the best practice in the clinical diagnosis of DLB. Future modifications of diagnostic criteria would ideally include the full range of clinical presentations that can be associated with LB disease.

Topics: Accidental Falls; Age Factors; Aged; alpha-Synuclein; Alzheimer Disease; Brain; Cerebral Cortex; Cognition Disorders; Diagnosis, Differential; Dysarthria; Electromyography; Hallucinations; Humans; Hypotension, Orthostatic; Lewy Bodies; Lewy Body Disease; Limbic System; Magnetic Resonance Imaging; Parkinson Disease; Substantia Nigra; Urinary Incontinence

The understanding of the molecular mechanisms underlying Parkinson's disease, progressive supranuclear palsy, and multiple system atrophy has made significant progress in the recent years. Lewy body appears to be principally made of alpha-synuclein, a presynaptic protein. It also contains ubiquitin and some components of the proteasome: this suggests that alteration of protein catabolism may be involved in its formation. In favor of this hypothesis, it should be noted that Parkin, a protein that is mutated in autosomal recessive Parkinson disease, is a ubiquitin ligase. Immunohistochemistry has shown that alpha-synuclein accumulates not only in the cell body of the neurones (Lewy body) but also in their processes (Lewy neurites); it has emphasized the severity of the pathology in the nucleus basalis of Meynert, amygdala, CA2-3 sector of the hippocampus and cerebral cortex. Cortical Lewy bodies are not considered any more the marker of dementia with Lewy bodies: they are, indeed, found in true Parkinson disease cases. In progressive supranuclear palsy, 4 repeats tau accumulates in the cytoplasm of neurones and glia. At electron microscopy, the accumulation is made of straight filaments. It involves not only the neurones (where it is the main constituent of the neurofibrillary tangles) but also the glia. Astrocytic tuft is to day considered the morphological marker of progressive supranuclear palsy. Tau protein accumulates in the cell body of the oligodendrocyte as a "coiled body"; the protein is also integrated in the myelin sheath, when the cytoplasm of the oligodendrocyte wraps around the axon. This explains the numerous "threads" that are visible in cases of progressive supranuclear palsy. Striato-nigral degeneration, sporadic olivo-ponto-cerebellar atrophy and primitive orthostatic hypotension are various clinico-pathologic aspects of the same disorder: multiple system atrophy. It is also characterized by a morphological marker: the accumulation of alpha-synuclein in the cytoplasm of glial cells, particularly oligodendrocytes. The term synucleinopathy has been proposed to describe both idiopathic Parkinson disease and multiple system atrophy. The reason explaining the cellular topography of alpha-synuclein accumulation, neuronal in Parkinson disease, glial in multiple system atrophy is still unknown.

Topics: alpha-Synuclein; Amygdala; Axons; Cerebral Cortex; Corpus Striatum; Cysteine Endopeptidases; Hippocampus; Humans; Hypotension, Orthostatic; Immunohistochemistry; Lewy Bodies; Ligases; Multienzyme Complexes; Multiple System Atrophy; Myelin Sheath; Nerve Tissue Proteins; Neuroglia; Oligodendroglia; Olivopontocerebellar Atrophies; Parkinsonian Disorders; Presynaptic Terminals; Proteasome Endopeptidase Complex; Supranuclear Palsy, Progressive; Synucleins; tau Proteins; Ubiquitin; Ubiquitin-Protein Ligases

To understand why autonomic failures, a common non-motor symptom of Parkinson's disease (PD), occur earlier than typical motor disorders.. Vagal application of DOPAL (3,4-dihydroxyphenylacetaldehyde) to simulate PD-like autonomic dysfunction and understand the connection between PD and cardiovascular dysfunction. Molecular and morphological approaches were employed to test the time-dependent alternation of α-synuclein aggregation and the ultrastructure changes in the heart and nodose (NG)/nucleus tractus solitarius (NTS).. Blood pressure (BP) and baroreflex sensitivity of DOPAL-treated rats were significantly reduced accompanied with a time-dependent change in orthostatic BP, consistent with altered echocardiography and cardiomyocyte mitochondrial ultrastructure. Notably, time-dependent and collaborated changes in Mon-/Tri-α-synuclein were paralleled with morphological alternation in the NG and NTS.. These all demonstrate that early autonomic dysfunction mediated by vagal application of DOPAL highly suggests the plausible etiology of PD initiated from peripheral, rather than central site. It will provide a scientific basis for the prevention and early diagnosis of PD.

Topics: 3,4-Dihydroxyphenylacetic Acid; alpha-Synuclein; Animals; Autonomic Nervous System Diseases; Baroreflex; Blood Pressure; Electrocardiography; Hypotension, Orthostatic; Male; Mitochondria, Heart; Myocardium; Myocytes, Cardiac; Nodose Ganglion; Parkinson Disease, Secondary; Rats; Rats, Sprague-Dawley; Vagus Nerve

The aim of our study was to assess the distribution of phosphorylated α-synuclein (p-syn) deposits in a patient affected by early stage Parkinson disease and orthostatic hypotension through a longitudinal skin biopsy study. We found widespread p-syn spatial diffusion from deep autonomic dermis nerve bundles to autonomic terminals, suggesting a centrifugal spread of p-syn from ganglia to the innervation target structures. Furthermore, the case suggests the possibility of discriminating synucleinopathies at an early stage of disease by means of skin biopsy. If confirmed, these data support skin biopsy as a useful and promising tool for the diagnosis, longitudinal evaluation, and pathological understanding of Parkinson disease.

Topics: Aged; alpha-Synuclein; Biopsy; Female; Humans; Hypotension, Orthostatic; Longitudinal Studies; Parkinson Disease; Phosphorylation; Skin

The differential diagnosis between multiple system atrophy parkinsonism type (MSA-P) and Parkinson's disease with orthostatic hypotension (PD+OH) is difficult because the 2 diseases have a similar clinical picture. The aim of this study is to distinguish MSA-P from PD+OH by immunostaining for abnormal phosphorylated α-synuclein at serine 129 (p-syn) in cutaneous nerves.. We recruited 50 patients with parkinsonism and chronic orthostatic hypotension: 25 patients fulfilled the diagnostic criteria for MSA-P and 25 patients for PD+OH. The patients underwent a skin biopsy from the cervical area, thigh, and leg to analyze somatic and autonomic skin innervation and p-syn in skin nerves.. Intraneural p-syn positivity was found in 72% of patients with MSA-P, mainly in distal skin sites. More important, p-syn deposits in MSA-P differed from PD+OH because they were mainly found in somatic fibers of subepidermal plexi, whereas scant autonomic fiber involvement was found in only 3 patients. All patients with PD+OH displayed widely distributed p-syn deposits in the autonomic skin fibers of proximal and distal skin sites, whereas somatic fibers were affected only slightly in 4 patients with PD+OH. Skin innervation mirrored p-syn deposits because somatic innervation was mainly reduced in MSA-P. Sympathetic innervation was damaged in PD+OH but fairly preserved in MSA-P.. The p-syn in cutaneous nerves allows the differentiation of MSA-P from PD+OH; MSA-P mainly shows somatic fiber involvement with relatively preserved autonomic innervation; and by contrast, PD+OH displays prevalent abnormal p-syn deposits and denervation in autonomic postganglionic nerves. © 2020 International Parkinson and Movement Disorder Society.

Topics: alpha-Synuclein; Biopsy; Humans; Hypotension, Orthostatic; Multiple System Atrophy; Parkinson Disease

Topics: Aged; Aged, 80 and over; alpha-Synuclein; Asian People; Female; Gene Duplication; Humans; Hypotension, Orthostatic; Japan; Lewy Body Disease; Male; Middle Aged; Parkinson Disease; Pedigree; Penetrance

This study aimed to investigate phosphorylated α-synuclein (p-syn) in autonomic skin nerves of Parkinson disease (PD) patients with and without orthostatic hypotension (OH). We studied 28 PD patients with normal corrected Mini-Mental State Examination including 14 patients with neurogenic OH (PD + OH) and 14 matched patients did not complain of OH (PD - OH); 7 of whom were re-evaluated over a follow-up period (4 ± 2 years). Skin biopsy was performed in proximal and distal sites. PD + OH patients showed a higher p-syn deposition than PD - OH, with widespread autonomic cholinergic and adrenergic skin nerve involvement. Over the follow-up period, PD - OH patients showed an increase in motor dysfunction scores without autonomic symptoms and a slight increase of skin p-syn deposition but still lower than PD + OH, mainly restricted to adrenergic fibers of skin vessels (SV). In summary, PD + OH patients showed a wide involvement of p-syn deposits in autonomic cholinergic and adrenergic skin nerves compared with PD - OH, and PD - OH patients showed a lower load of skin p-syn restricted to adrenergic fibers of SV still persisting over the follow-up period. The data supported a different pathogenesis between PD + OH and PD - OH and may help to identify a specific diagnostic trait for PD + OH.

Topics: Aged; Aged, 80 and over; alpha-Synuclein; Biomarkers; Female; Follow-Up Studies; Humans; Hypotension, Orthostatic; Male; Middle Aged; Nerve Fibers; Parkinson Disease; Phosphorylation; Skin

Accumulation of α-synuclein in multiple system atrophy (MSA) affects medullary autonomic and respiratory control areas, including the rostral ventrolateral medulla and raphe nuclei. Relative neuronal vulnerability and its relationship to α-synuclein accumulation in these areas are unknown. The aim of this study was to determine the extent of loss of adrenergic neurons in the rostral ventrolateral medulla and serotonergic neurons in the ventrolateral medulla and raphe nuclei and its relationship with α-synuclein accumulation.. Medullary sections from 7 MSA and 6 control subjects were processed for tyrosine hydroxylase, tryptophan hydroxylase, and α-synuclein immunoreactivity. Neuronal counts were performed stereologically, whereas α-synuclein burden in oligodendrocytes and neurons was quantified using object detection density (area/mm2).. All MSA cases had orthostatic hypotension; 5 had laryngeal stridor. There was marked neuronal loss in the rostral ventrolateral medulla and medullary raphe in all cases. Most severely affected were tyrosine hydroxylase ventrolateral medulla (C1) neurons (83% reduction), followed by tryptophan hydroxylase neurons in the ventrolateral medulla (70%), raphe obscurus (56%), pallidus (57%), and magnus (47%). α-Synuclein accumulation occurred predominantly as glial cytoplasmic inclusions with rare α-synuclein accumulation occurring within the remaining neurons. Density of α-synuclein did not correlate with neuronal loss in any of the areas analyzed, and there was no correlation between α-synuclein density and disease duration for any regions of interest.. These findings indicate that in MSA adrenergic neurons are more susceptible than serotonergic neurons in the medulla. Further, loss of medullary monoaminergic neurons may progress independently from α-synuclein accumulation in MSA. © 2016 International Parkinson and Movement Disorder Society.

Topics: Adrenergic Neurons; Aged; alpha-Synuclein; Female; Humans; Hypotension, Orthostatic; Laryngeal Diseases; Male; Medulla Oblongata; Middle Aged; Multiple System Atrophy; Raphe Nuclei; Respiratory Sounds; Serotonergic Neurons

A 74-year-old man gradually developed muscular weakness in the upper extremities, followed by dyspnea and dysarthria over a 6-month period. He was admitted to our facility and diagnosed as having amyotrophic lateral sclerosis (ALS) based on clinical and neurophysiological findings. Two months later, transtracheal positive pressure ventilation (TPPV) was started. During his clinical course, orthostatic hypotension occurred a few times. He also had two episodes of transient cardiac arrest, and he died 15 months after disease onset. At autopsy, the brain, weighing 850 g, showed diffuse cortical atrophy, preferentially involving the frontal lobes. Microscopic findings included severe loss of neurons in the motor cortex, the motor nuclei of the brainstem and the anterior horns of the spinal cord, and mild loss of axons and myelin in the corticospinal tract. Trans-activation response DNA protein 43 (TDP-43) immunoreactive cytoplasmic inclusions, the pathognomonic findings for ALS, were noted in the nucleus facialis, nucleus ambiguus, and in the anterior horn of the spinal cord. In addition, Lewy bodies and Lewy neurites were found in the brainstem and in the nucleus intermediolateralis of the thoracic cord. The concomitant alpha-synuclein pathology may have been partly related to possible autonomic dysfunction underlying the two episodes of cardiac arrest.

Topics: Aged; alpha-Synuclein; Amyotrophic Lateral Sclerosis; Autopsy; Brain; DNA-Binding Proteins; Fatal Outcome; Heart Arrest; Humans; Hypotension, Orthostatic; Immunohistochemistry; Lewy Bodies; Male

Attention has been drawn to cardiac sympathetic denervation in Parkinson's disease (PD) based on clinical studies using [123I] metaiodobenzylguanidine scintigraphy; however, the histologic correlates and time course of cardiac sympathetic denervation are poorly understood. To address these issues, we used tyrosine hydroxylase (TH) immunohistochemistry to detect cardiac sympathetic nerve fibers in the epicardium of 4 normal controls, 11 cases with incidental Lewy bodies (iLBs), and 14 cases of PD. Cardiac sympathetic innervation was significantly less in PD than in normal controls and cases with iLBs (P < 0.05). There was also a decrease in TH-immunoreactive fibers in iLB cases compared to normal controls (P < 0.01). TH-immunoreactive fibers correlated with the PD stage (r = -0.75, P < 0.001), as well as with Hoehn & Yahr clinical stage (r = -0.61, P < 0.001), and disease duration (r = -0.63, P < 0.001). Immunohistochemistry for alpha-synuclein showed neurites in epicardium in PD and iLB cases, but not in normal controls. The density of alpha-synuclein neurites correlated with Braak PD stage (r = 0.38, P < 0.05), Hoehn & Yahr clinical stage (r = 0.44, P < 0.05), and disease duration (r = 0.42, P < 0.05). This study demonstrates that cardiac sympathetic degeneration and alpha-synuclein pathology is present in presymptomatic phase of PD, and that both increase with disease duration and severity.

Topics: Aged; Aged, 80 and over; alpha-Synuclein; Brain; Disease Progression; Female; Heart; Humans; Hypotension, Orthostatic; Lewy Bodies; Male; Nerve Degeneration; Nerve Fibers; Neurites; Parkinson Disease; Pericardium; Spinal Cord; Sympathetic Nervous System; Tyrosine 3-Monooxygenase

We report the case of an elderly man of Greek background who presented with progressive cognitive decline and motor parkinsonism on a background of a strong family history of Parkinson's disease. Associated symptoms included visual hallucinations, excessive daytime drowsiness, recurrent falls, orthostatic hypotension and urinary incontinence. His major clinical symptoms and signs fulfilled consensus criteria for a clinical diagnosis of dementia with Lewy bodies. An alpha-synuclein gene mutation analysis for the G209A substitution was positive. We conclude that the alpha-synuclein (G209A) gene mutation genotype should be considered in the differential diagnosis of dementia with Lewy bodies, particularly in patients with European ancestry and a family history of Parkinson's disease.

Topics: Accidental Falls; Aged; alpha-Synuclein; Cognition Disorders; Diagnosis, Differential; Disease Progression; DNA Mutational Analysis; Fatal Outcome; Genetic Markers; Genetic Predisposition to Disease; Genotype; Greece; Hallucinations; Humans; Hypotension, Orthostatic; Lewy Body Disease; Male; Mutation; Parkinsonian Disorders; Respiratory Tract Infections; Urinary Incontinence

Parkinson's disease patients frequently have symptoms and signs of autonomic nervous dysfunction that are the source of considerable disability. Recent studies have revealed that most patients with Parkinson's disease, and all with Parkinson's disease-associated orthostatic hypotension, have a loss of cardiac sympathetic innervation. Familial Parkinson's disease, caused by mutation of the gene encoding alpha-synuclein, also features orthostatic hypotension, sympathetic neurocirculatory failure and cardiac sympathetic denervation. We have recently described a whole-gene triplication of alpha-synuclein causing Lewy body parkinsonism in a large, well characterized family called the 'Iowa kindred'. Here we report the results of cardiac PET scanning using the sympathoneural imaging agent, 6-[18F]fluorodopamine in affected and unaffected members of this kindred. Four family members were studied, two with parkinsonism, one clinically normal and one with benign essential tremor alone. Both affected members had obvious loss of cardiac sympathetic innervation; the unaffected member had normal innervation, as did the member with isolated essential tremor. The results indicate that, in this family, where disease is caused by overexpression of normal alpha-synuclein, cardiac sympathetic denervation cosegregates with parkinsonism. Post-mortem studies have demonstrated synuclein-positive Lewy body formation in the brains of individuals with parkinsonism who were also in the family described here and who also carry this triplication. These results indicate that both parkinsonism and cardiac sympathetic denervation can result from an excess of normal synuclein.

Topics: Aged; alpha-Synuclein; Autonomic Nervous System Diseases; Dopamine; Heart; Humans; Hypotension, Orthostatic; Middle Aged; Mutation; Nerve Tissue Proteins; Parkinson Disease; Pedigree; Synucleins; Tomography, Emission-Computed; Valsalva Maneuver

Topics: alpha-Synuclein; Heart; Humans; Hypotension, Orthostatic; Mutation; Nerve Tissue Proteins; Parkinson Disease; Sympathetic Nervous System; Synucleins