Correlations between serotonin impairments and clinical indices in multiple system atrophy.

BACKGROUND AND PURPOSE: Multiple system atrophy (MSA) is a neurodegenerative disease with characteristic motor and autonomic symptoms. Impaired brain serotonergic innervation can be associated with various clinical indices of MSA; however, the relationship between clinical symptoms and cerebrospinal fluid (CSF) levels of 5-hydroxyindole acetic acid (5-HIAA), a main serotonin metabolite, has not been fully elucidated. METHODS: To compare CSF 5-HIAA levels between patients with MSA and healthy controls, we included 33 controls and 69 MSA patients with either predominant parkinsonian or cerebellar ataxia subtypes. CSF 5-HIAA levels were measured using high-performance liquid chromatography. Additionally, we investigated correlations between CSF 5-HIAA and various clinical indices in 34 MSA patients. RESULTS: CSF 5-HIAA levels were significantly lower in MSA patients than in controls (p < 0.0001). Probable MSA patients had lower CSF 5-HIAA levels than possible MSA patients (p < 0.001). In MSA patients, CSF 5-HIAA levels were inversely correlated with scores in Parts 1, 2, and 4 of the Unified Multiple System Atrophy Rating Scale, and with systolic and diastolic blood pressure in Part 3. Structural equation modeling revealed significant paths between serotonin and clinical symptoms, and significance was highest for activities of daily living, walking, and body sway. CONCLUSIONS: Serotonin dysfunction, as assessed by CSF 5-HIAA levels, may implicate greater MSA severity.

Molecular aggregation in liquid-crystalline layers crucially affects their physics: smectic A (SmA)-nematic (N) phase transition.

Recently, two molecular packing modes of the alkyl chain in smectic A (SmA) liquid crystal phases were revealed: normal and tilted types, which are named by the orientation relative to the layer normal. This study reveals the relationship between the packing mode and thermodynamic order of the SmA-nematic (N) phase transition. Two normal type and three tilted type mesogens were subject to thermodynamic and structural experiments. The DSC results showed that the SmA-N phase transitions of the normal and tilted types are of the second and first order, respectively. The analysis of the intensities of reflections in wide-angle X-ray diffraction related to the periodicity of the SmA layer yielded the distribution of the mass centers of molecules along the normal to the SmA layers. The resultant distribution offered a rationale for the correlation of the thermodynamic order of the SmA-N phase transition and molecular packing modes in the SmA phases based on the Meyer-Lubensky theory.

Genome-wide association study identifies a new susceptibility locus in PLA2G4C for Multiple System Atrophy.

To elucidate the molecular basis of multiple system atrophy (MSA), a neurodegenerative disease, we conducted a genome-wide association study (GWAS) in a Japanese MSA case/control series followed by replication studies in Japanese, Korean, Chinese, European and North American samples. In the GWAS stage rs2303744 on chromosome 19 showed a suggestive association ( P = 6.5 × 10 -7 ) that was replicated in additional Japanese samples ( P = 2.9 × 10 -6 . OR = 1.58; 95% confidence interval, 1.30 to 1.91), and then confirmed as highly significant in a meta-analysis of East Asian population data ( P = 5.0 × 10 -15 . Odds ratio= 1.49; 95% CI 1.35 to 1.72). The association of rs2303744 with MSA remained significant in combined European/North American samples ( P =0.023. Odds ratio=1.14; 95% CI 1.02 to 1.28) despite allele frequencies being quite different between these populations. rs2303744 leads to an amino acid substitution in PLA2G4C that encodes the cPLA2γ lysophospholipase/transacylase. The cPLA2γ-Ile143 isoform encoded by the MSA risk allele has significantly decreased transacylase activity compared with the alternate cPLA2γ-Val143 isoform that may perturb membrane phospholipids and α-synuclein biology.

Associations of Alzheimer's-related plasma biomarkers with cognitive decline in Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is associated with cognitive decline through multiple mechanisms, including Alzheimer's disease (AD) pathology and cortical Lewy body involvement. However, its underlying mechanisms remain unclear. Recently, AD-related plasma biomarkers have emerged as potential tools for predicting abnormal pathological protein accumulation. We aimed to investigate the association between AD-related plasma biomarkers and cognitive decline in PD patients. METHODS: Plasma biomarkers were measured in 70 PD patients (49 with nondemented Parkinson's disease (PDND) and 21 with Parkinson's disease dementia (PDD)) and 38 healthy controls (HCs) using a single-molecule array. The study evaluated (1) the correlation between plasma biomarkers and clinical parameters, (2) receiver operating characteristic curves and areas under the curve to evaluate the discrimination capacity of plasma biomarkers among groups, and (3) a generalized linear model to analyze associations with Addenbrooke's Cognitive Examination-Revised and Montreal Cognitive Assessment-Japanese version scores. RESULTS: Plasma glial fibrillary acidic protein significantly correlated with cognitive function tests, including all subdomains, with a notable increase in the PDD group compared with the HC and PDND groups, while plasma neurofilament light chain captured both cognitive decline and disease severity in the PDND and PDD groups. Plasma beta-amyloid 42/40 and pholphorylated-tau181 indicated AD pathology in the PDD group, but plasma beta-amyloid 42/40 was increased in the PDND group compared with HCs and decreased in the PDD group compared with the PDND group. CONCLUSIONS: AD-related plasma biomarkers may predict cognitive decline in PD and uncover underlying mechanisms suggesting astrocytic pathologies related to cognitive decline in PD.

Enzymatic properties and clinical associations of serum alpha-galactosidase A in Parkinson's disease.

OBJECTIVE: Recent studies have revealed an association between Parkinson's disease (PD) and Fabry disease, a lysosomal storage disorder; however, the underlying mechanisms remain to be elucidated. This study aimed to investigate the enzymatic properties of serum alpha-galactosidase A (GLA) and compared them with the clinical parameters of PD. METHODS: The study participants consisted of 66 sporadic PD patients and 52 controls. We measured serum GLA activity and calculated the apparent Michaelis constant (Km ) and maximal velocity (Vmax ) by Lineweaver-Burk plot analysis. Serum GLA protein concentration was measured by enzyme-linked immunosorbent assay. We examined the potential correlations between serum GLA activity and GLA protein concentration and clinical features and the plasma neurofilament light chain (NfL) level. RESULTS: Compared to controls, PD patients showed significantly lower serum GLA activity (P < 0.0001) and apparent Vmax (P = 0.0131), but no change in the apparent Km value. Serum GLA protein concentration was lower in the PD group (P = 0.0168) and was positively associated with GLA activity. Serum GLA activity and GLA protein concentration in the PD group showed a negative correlation with age. Additionally, serum GLA activity was negatively correlated with the motor severity score and the level of plasma NfL, and was positively correlated with the score of frontal assessment battery. INTERPRETATION: This study highlights that the lower serum GLA activity in PD is the result of a quantitative decrement of GLA protein in the serum and that it may serve as a biomarker of disease severity.

[Limitations of the Second Consensus Statement on the Diagnosis of Multiple System Atrophy].

The Second Consensus Statement on the Diagnosis of Multiple System Atrophy (MSA), issued in 2008, has unified the concept of MSA and significantly advanced clinical and drug discovery research. However, subsequent developments in research have revealed several critical findings that would affect the diagnostic sensitivity, specificity, and positive predictive value of the consensus statement. In this review, we discuss the limitations of diagnostic sensitivity for early diagnosis; positioning of orthostatic hypotension; diagnostic categories; exclusion criteria such as elderly onset, family history, and dementia; differentiation from progressive supranuclear palsy; and imaging findings of the Second Consensus Statement.

Long-term response to immunotherapy in patients with hypertrophic pachymeningitis.

Objective: In this study, we aimed to clarify the relationship between initial treatment response, prednisolone (PSL) dosage, clinical type, and recurrence in patients with hypertrophic pachymeningitis (HP). Methods: The study cohort comprised eight patients with HP who had been admitted to our hospital from April 2015 to June 2020. Diagnostic criteria for HP included neurological abnormalities and dural thickening on magnetic resonance gadolinium-enhanced T1-weighted images. Results: Relevant characteristics of the eight study patients are as follows. There were two men and six women. The average age at onset was 58.3 (range: 29-79) years. Three of them had myeloperoxidase-antineutrophil cytoplasmic antibody-related vasculitis, one immunoglobulin G4-related disease, and one ulcerative colitis. The remaining three patients had idiopathic HP. The average maximum dosage of PSL was 0.79 mg/kg/day, and the average daily maintenance dosage 0.18 mg/kg/day. Three patients needed additional immunosuppressive drugs. Both idiopathic and secondary HP initially responded well to PSL, with improvement in activities of daily living. Six patients had some sequelae related to cranial nerve involvement. No relapses occurred while the patients were taking moderate doses of PSL; however, all patients with idiopathic HP had recurrences when their PSL dosage was reduced. Conclusions: Patients with idiopathic HP and HP associated with immune disorders respond to steroids and immunosuppressive drugs and recover well. However, there is a high rate of relapse after reduction of PSL dosage, mainly in those with idiopathic HP.

Multiple System Atrophy: Advances in Diagnosis and Therapy.

This review summarizes improvements in understanding the pathophysiology and early clinical symptoms of multiple system atrophy (MSA) and advancements in diagnostic methods and disease-modifying therapies for the condition. In 2022, the Movement Disorder Society proposed new diagnostic criteria to develop disease-modifying therapies and promote clinical trials of MSA since the second consensus was proposed in 2008. Regarding pathogenesis, cutting-edge findings have accumulated on the interactions of α-synuclein, neuroinflammation, and oligodendroglia with neurons. In neuroimaging, introducing artificial intelligence, machine learning, and deep learning has notably improved diagnostic accuracy and individual analyses. Advancements in treatment have also been achieved, including immunotherapy therapy against α-synuclein and serotonin-targeted and mesenchymal stem cell therapies, which are thought to affect several aspects of the disease, including neuroinflammation. The accelerated progress in clarifying the pathogenesis of MSA over the past few years and the development of diagnostic techniques for detecting early-stage MSA are expected to facilitate the development of disease-modifying therapies for one of the most intractable neurodegenerative diseases.

Molecular dynamics and kinetics of isothermal cold crystallization with tunable dimensionality in a molecular glass former, 5'-(2,3-difluorophenyl)-2'-ethoxy-4-pentyloxy-2,3-difluorotolane.

This paper characterizes the molecular mobility that triggers the cold crystallization abilities in 5'-(2,3-difluorophenyl)-2'-ethoxy-4-pentyloxy-2,3-difluorotolane (short name DFP25DFT) material by broadband dielectric spectroscopy (BDS). We analyze the properties of identified molecular motions by referring to the Vogel-Fulcher-Tammann (VFT) model for the structural α-process associated with molecular rotation in isotropic liquid and the Eyring and Starkweather approach for the thermally activated processes, ß-process related to intramolecular movement in liquid and glassy state and emerging during cold crystallization α'-process ascribed to confined movements of molecules located adjacent to crystalline surfaces. To characterize the material, we employ single-crystal X-ray diffraction, differential scanning calorimetry (DSC), adiabatic calorimetry, and polarizing optical microscopy (POM), while we utilize molecular mechanics simulations (MM2) to explore molecular flexibility. Our study focuses on inter- and intramolecular interactions that determine the cold-crystallization tendency. We demonstrate that the solidification path is controlled by the fragility of the system, the dipole-dipole attraction, and the intramolecular dynamics. The study of cold crystallization kinetics under isothermal conditions reveals the complexity of the process: the formation of two crystalline phases, Cr2 and Cr3, proceeding in different modes. This feature discloses the possibility of switching the crystal growth between three- and two-dimensional in the cold-crystallization process driven by different mechanisms.

[Long COVID: Pathogenesis and Therapeutic Approach].

A group of patients with coronavirus disease 2019 (COVID-19) exhibited various persistent or new systemic symptoms, including psychiatric symptoms, sleep disturbances, exercise intolerance, arthralgia, headache, cognitive decline, brain fog, and autonomic symptoms, all of which persisted long after the resolution of infectious symptoms. Several imaging studies have shown that long COVID cases present with decreased glucose metabolism and progressive brain atrophy. Although no single pathological hypothesis thoroughly explains the varied clinical presentations and timings, the following have attracted attention: 1) persistent viral infection, 2) persistent inflammation, 3) involvement of the autoimmune system, and 4) mitochondrial dysfunction. In all these hypotheses, inflammatory cytokines may be involved in orthostatic dysregulation by decreasing the expression and activity of ACE2, consequently changing the blood pressure through vagus nerve hyperactivation. Myopathy and peripheral neuropathy may also be caused by direct infection of the muscles and nerves, hypoxia, mitochondrial damage, and cytokine storm. Furthermore, multiple theories regarding the mechanisms by which systemic inflammatory findings affect the central nervous system have been postulated, including neuroinflammation caused by inflammatory cells crossing the blood-brain barrier via choroid plexus cells and the involvement of various autoantibodies. Despite these findings, no definitive consensus has been reached due to the complexity and diversity of COVID-19 pathophysiology. Thus, it is essential to understand the neurological symptoms and pathophysiology involved in long COVID.

Nemaline Myopathy Initially Diagnosed as Right Heart Failure with Type 2 Respiratory Failure.

Nemaline myopathy (NM) is a rare muscle disease with various clinical types. In some cases, NM can lead to type 2 respiratory failure and right heart failure. We herein report a patient with congenital NM with nebulin gene mutation who presented with acute right heart failure and type 2 respiratory failure due to respiratory muscle paralysis after upper respiratory tract infection, needing a permanent ventilator for assistance. However, the limb and trunk muscle strengths were within normal limits. This case showed that NM should be considered as a cause of right heart failure and type 2 respiratory failure.

Severe dysautonomia in glycine receptor antibody-positive progressive encephalomyelitis with rigidity and myoclonus (PERM): A case report.

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a severe form of stiff-person spectrum disorder. We report a 59-year-old man who presented with progressive encephalomyelitis causing diplopia, bulbar palsy, severe dysautonomia, followed by stiffness and myoclonic cluster. Laboratory tests showed mild pleocytosis, with markedly elevated plasma levels of norepinephrine, epinephrine, and arginine vasopressin. Glycine-receptor antibodies were identified in both serum and CSF. Despite a poor response to methylprednisolone, immunoglobulins, and plasma exchange, α-blocker stabilized dysautonomia. Dysautonomia is presumed to be due to antibody-mediated disinhibited sympathetic hyperactivity; however, this case suggests that concomitant use of α-blocker with immunotherapy may ameliorate dysautonomia.

Characteristics of Neural Network Changes in Normal Aging and Early Dementia.

To understand the mechanisms underlying preserved and impaired cognitive function in healthy aging and dementia, respectively, the spatial relationships of brain networks and mechanisms of their resilience should be understood. The hub regions of the brain, such as the multisensory integration and default mode networks, are critical for within- and between-network communication, remain well-preserved during aging, and play an essential role in compensatory processes. On the other hand, these brain hubs are the preferred sites for lesions in neurodegenerative dementias, such as Alzheimer's disease. Disrupted primary information processing networks, such as the auditory, visual, and sensorimotor networks, may lead to overactivity of the multisensory integration networks and accumulation of pathological proteins that cause dementia. At the cellular level, the brain hub regions contain many synapses and require a large amount of energy. These regions are rich in ATP-related gene expression and had high glucose metabolism as demonstrated on positron emission tomography (PET). Importantly, the number and function of mitochondria, which are the center of ATP production, decline by about 8% every 10 years. Dementia patients often have dysfunction of the ubiquitin-proteasome and autophagy-lysosome systems, which require large amounts of ATP. If there is low energy supply but the demand is high, the risk of disease can be high. Imbalance between energy supply and demand may cause accumulation of pathological proteins and play an important role in the development of dementia. This energy imbalance may explain why brain hub regions are vulnerable to damage in different dementias. Here, we review (1) the characteristics of gray matter network, white matter network, and resting state functional network changes related to resilience in healthy aging, (2) the mode of resting state functional network disruption in neurodegenerative dementia, and (3) the cellular mechanisms associated with the disruption.

Magnetic Resonance Neurography in a Patient with Distal Neuralgic Amyotrophy.

The pathophysiology of neuralgic amyotrophy (NA) remains to be elucidated. However, high-resolution magnetic resonance imaging and ultrasound sonography have provided new insights into the mechanism underlying the development of NA and its diagnosis. We report a case of idiopathic distal NA with hyperintensity and thickening in the inferior trunk extending to the posterior and medial fasciculus of the left brachial plexus, which was detected by magnetic resonance neurography (MRN) with diffusion-weighted whole-body imaging with background body signal suppression (DWIBS). The abnormal signal intensity diminished after the improvement of symptoms following corticosteroid treatment. MRN with DWI can help diagnose distal NA and evaluate the post-therapeutic response.

[Sporadic Cerebellar Ataxia: Multiple System Atrophy and Mono System Atrophy].

Cerebellar ataxia-predominant multiple system atrophy (MSA-C) and cortical cerebellar atrophy are representative diseases of adult-onset sporadic degenerative ataxia. Both diseases are distinctly different because of α-synuclein pathology. However, it takes approximately 2 years for cerebellar ataxia to progress to concomitant severe autonomic dysfunction in patients with MSA-C. The period of only cerebellar ataxia (mono system atrophy) may extend to more than 10 years. Understanding mono system atrophy is vital for the early diagnosis and drug development for MSA. In this review, we discuss mono system atrophy focusing on the concept and natural history and the possibility of the of early diagnosis and disease-modifying therapy for MSA.

Longitudinal Change of DAT SPECT in Parkinson's Disease and Multiple System Atrophy.

BACKGROUND: Both Parkinson's disease (PD) and multiple system atrophy (MSA) are neurodegenerative disorder affecting striatonigral system. Although various lines of evidence demonstrate that dopaminergic neuron degeneration emerges before the onset of motor symptoms in PD, preclinical/prodromal progression of neurodegeneration is far less understood in MSA. OBJECTIVE: The aim of this study was to clarify the difference in the progression of dopaminergic degeneration in MSA and PD using dopamine transporter single-photon emission computed tomography (DAT SPECT). METHODS: We analyzed longitudinal data of the specific binding ratio (SBR), a measure of striatal radiotracer uptake, in DAT SPECT from 7 patients with MSA-C, 5 patients with MSA-P, and 18 patients with PD. We performed 2.7±0.7 scans with an interval of 9.85±6.00 months for MSA and 2 scans with an interval of 2.16±0.16 years for PD. RESULTS: The rate of SBR decline was faster in both subtypes of MSA compared with PD, but the value was similar between MSA-P and MSA-C. The estimated SBR at the onset of initial motor symptoms was lower in PD and MSA-P than in MSA-C, especially in the predominantly affected side. SBR of the predominantly affected side starts to decrease before the onset of motor symptoms in PD and MSA-P, whereas the initiation of SBR decline is around the onset in MSA-C individuals. The decline of SBR in the less affected side was not clearly shown before the onset in MSA-P or MSA-C. CONCLUSIONS: Our results suggest that the SBR in DAT SPECT analysis is an important pathophysiological marker reflecting the disease- and subtype-specific progression of dopaminergic degeneration in MSA and PD.

Alterations in Cognition-Related Cerebello-Cerebral Networks in Multiple System Atrophy.

We aimed to elucidate the effect of cerebellar degeneration in relation to cognition in multiple system atrophy (MSA). Thirty-two patients diagnosed with probable MSA and 32 age- and gender-matched healthy controls (HCs) were enrolled. We conducted voxel-based morphometry (VBM) for anatomical images and independent component analysis (ICA), dual-regression analysis, and seed-based analysis for functional images with voxel-wise gray matter correction. In the MSA group, a widespread cerebellar volume loss was observed. ICA and dual-regression analysis showed lower functional connectivity (FC) in the left executive control and salience networks in regions located in the cerebellum. Seed-based analysis using the identified cerebellar regions as seeds showed extensive disruptions in cerebello-cerebral networks. Global cognitive scores correlated with the FC values between the right lobules VI/crus I and the medial prefrontal/anterior cingulate cortices and between the same region and the amygdala/parahippocampal gyrus. Our study indicates that cerebellar degeneration in MSA causes segregation of cerebellar-cerebral networks. Furthermore, the cognitive deficits in MSA may be driven by decreased cerebello-prefrontal and cerebello-amygdaloid functional connections.

Acute Unilateral Isolated Oculomotor Nerve Palsy in an Adult Patient with Influenza A.

An otherwise healthy 44-year-old woman exhibited isolated unilateral oculomotor nerve palsy accompanied by an influenza A infection. An intra-orbital MRI scan revealed that her right third intracranial nerve was enlarged and enhanced. She recovered completely during the first month after treatment with oseltamivir phosphate. Although intracranial nerve disorders that result from influenza infections are most frequently reported in children, it is noteworthy that influenza can also cause focal intracranial nerve inflammation with ophthalmoparesis in adults. These disorders can be diagnosed using intra-orbital MRI scans with appropriate sequences and through immunological assays to detect the presence of antiganglioside antibodies.

Clinical and Imaging Features of Multiple System Atrophy: Challenges for an Early and Clinically Definitive Diagnosis.

Multiple system atrophy (MSA) is an adult-onset, progressive neurodegenerative disorder. Patients with MSA show various phenotypes during the course of their illness, including parkinsonism, cerebellar ataxia, autonomic failure, and pyramidal signs. Patients with MSA sometimes present with isolated autonomic failure or motor symptoms/ signs. The median duration from onset to the concomitant appearance of motor and autonomic symptoms is approximately 2 years but can range up to 14 years. As the presence of both motor and autonomic symptoms is essential for the current diagnostic criteria, early diagnosis is difficult when patients present with isolated autonomic failure or motor symptoms/signs. In contrast, patients with MSA may show severe autonomic failure and die before the presentation of motor symptoms/signs, which are currently required for the diagnosis of MSA. Recent studies have also revealed that patients with MSA may show nonsupporting features of MSA such as dementia, hallucinations, and vertical gaze palsy. To establish early diagnostic criteria and clinically definitive categorization for the successful development of disease-modifying therapy or symptomatic interventions for MSA, research should focus on the isolated phase and atypical symptoms to develop specific clinical, imaging, and fluid biomarkers that satisfy the requirements for objectivity, for semi- or quantitative measurements, and for uncomplicated, worldwide availability. Several novel techniques, such as automated compartmentalization of the brain into multiple parcels for the quantification of gray and white matter volumes on an individual basis and the visualization of α-synuclein and other candidate serum and cerebrospinal fluid biomarkers, may be promising for the early and clinically definitive diagnosis of MSA.

Corpus callosal involvement is correlated with cognitive impairment in multiple system atrophy.

OBJECTIVE: We examined the anatomical involvement related to cognitive impairment in patients with multiple system atrophy (MSA). METHODS: We examined 30 patients with probable MSA and 15 healthy controls. All MSA patients were assessed by the Unified MSA-Rating scale and Addenbrooke's Cognitive Examination-Revised (ACE-R). We classified 15 MSA patients with ACE-R scores > 88 as having normal cognition (MSA-NC) and 15 with scores ≤ 88 as having cognitive impairment (MSA-CI). All subjects underwent 3 T MRI scanning and were investigated using voxel-based morphometry and diffusion tensor imaging. RESULTS: Both the MSA-NC and MSA-CI patients exhibited cerebellar but not cerebral atrophy in voxel-based morphometry compared to controls. In contrast, tract-based spatial statistics revealed widespread and significantly decreased fractional anisotropy (FA) values, as well as increased mean diffusivity, radial diffusivity, and axial diffusivity in both the cerebrum and cerebellum in MSA-CI patients compared to controls. MSA-NC patients also exhibited similar involvement of the cerebellum but less extensive involvement of the cerebrum compared with the MSA-CI patients. In particular, FA values in MSA-CI patients were significantly decreased in the anterior part of the left corpus callosum compared with those in MSA-NC patients. The mean FA values in the left anterior part of the corpus callosum were significantly correlated with total ACE-R scores and subscores (memory, fluency, and language) in MSA patients. CONCLUSIONS: Decreased FA values in the anterior corpus callosum showed a significant correlation with cognitive impairment in MSA.