Bradykinesia and rigidity modulated by functional connectivity between the primary motor cortex and globus pallidus in Parkinson's disease.

The mechanisms underlying motor fluctuations in patients with Parkinson's disease (PD) are currently unclear. Regional brain stimulation reported the changing of motor symptoms, but the correlation with functional connectivity (FC) in the brain network is not fully understood. Hence, our study aimed to explore the relationship between motor symptom severity and FC using resting-state functional magnetic resonance imaging (rsfMRI) in the "on" and "off" states of PD. In 26 patients with sporadic PD, FC was assessed using rsfMRI, and clinical severity was analyzed using the motor part of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS Part III) in the on and off states. Correlations between FC values and MDS-UPDRS Part III scores were assessed using Pearson's correlation coefficient. The correlation between FC and motor symptoms differed in the on and off states. FC between the ipsilateral precentral gyrus (PreCG) and globus pallidus (GP) correlated with the total MDS-UPDRS Part III scores and those for bradykinesia/rigidity in the off state. Lateralization analysis indicated that FC between the PreCG and GP correlated with the contralateral total MDS-UPDRS Part III scores and those for bradykinesia/rigidity in the off state. Aberrant FC in cortico-striatal circuits correlated with the severity of motor symptoms in PD. Cortico-striatal hyperconnectivity, particularly in motor pathways involving PreCG and GP, is related to motor impairments in PD. These findings may facilitate our understanding of the mechanisms underlying motor symptoms in PD and aid in developing treatment strategies such as brain stimulation for motor impairment.

Electroencephalographic-Based Functional Connectivity Networks of Visual Hallucinations and Visuospatial Dysfunctions in Parkinson's Disease.

Visual dysfunction is an important nonmotor symptom of Parkinson's disease (PD). Visual hallucinations (VHs) and visuospatial dysfunctions (VSDs) are common visual dysfunctions in PD; however, the underlying mechanisms remain unclear. Our study aimed to evaluate neuronal synchronization between patients with PD with and without VH or VSD using electroencephalographic (EEG) coherence analysis. Twenty-four patients with sporadic PD were evaluated for the presence of VH and VSD, and were divided into VH-negative and VH-positive groups, and these groups were further subdivided by VSD status. Coherence analysis was performed on EEG data. Whole-brain and regional coherences were calculated and compared between the groups. There was a significant difference in frontal-frontal coherence between the VH+ VSD- and VH+ VSD+ groups (p = 0.026). Our findings suggest that reduced EEG coherence in frontal regions might be involved in VSD in patients with PD. Reduced neuronal synchronization between the frontal lobes may contribute to the disruption of visual processing in PD.

Improvement in lower extremity hemiplegia in a post-operative brain tumor patient by applying an integrated volitional control electrical stimulator.

[Purpose] This study aimed to evaluate the improvement in lower extremity hemiplegia following brain tumor operation with an integrated volitional control electrical stimulator (IVES). [Participant and Methods] A 40 year-old male with anaplasic oligodendroglioma in the right frontal lobe underwent IVES in the rectus femoris and tibialis anterior muscles using the power-assist and sensor-trigger modes. Lower extremity motor function was assessed before and after the therapy sessions. An assessment was conducted using various techniques, including static posturography and surface electromyography. [Results] Static posturography showed an improvement in the center of pressure and sway area after IVES gait training. Based on a time-series statistical parametric mapping analysis, the activation pattern of each muscle after the treatment was different. Muscle synergy analysis revealed decreased total variance accounted for by a single synergy in the affected and normal sides after the treatment. [Conclusion] Patients with chronic hemiplegic lower extremity impairment responded well to IVES gait training. Electromyography-triggered functional electrical stimulation may enhance sensory-motor integration. Proprioceptive feedback plays a crucial role in improving motor control.

Single-cell transcriptomics reveals multiple neuronal cell types in human midbrain-specific organoids.

Human stem cell-derived organoids have great potential for modelling physiological and pathological processes. They recapitulate in vitro the organization and function of a respective organ or part of an organ. Human midbrain organoids (hMOs) have been described to contain midbrain-specific dopaminergic neurons that release the neurotransmitter dopamine. However, the human midbrain contains also additional neuronal cell types, which are functionally interacting with each other. Here, we analysed hMOs at high-resolution by means of single-cell RNA sequencing (scRNA-seq), imaging and electrophysiology to unravel cell heterogeneity. Our findings demonstrate that hMOs show essential neuronal functional properties as spontaneous electrophysiological activity of different neuronal subtypes, including dopaminergic, GABAergic, glutamatergic and serotonergic neurons. Recapitulating these in vivo features makes hMOs an excellent tool for in vitro disease phenotyping and drug discovery.

Reduction in presynaptic dopamine transporter may be associated with future problematic delusion.

OBJECTIVES: Psychosis, especially in delusions, greatly impairs the quality of life of patients with Parkinson's disease (PD) and their caregivers. Few objective risk indicators of the association between psychosis and clinical features has been reported. It is unclear whether the reduction in DAT binding represents the underlying mechanism of delusion or its association. There are no long-term data on the objective prognostic value of DAT binding for delusions. We investigated whether DAT binding at baseline can be a prognostic risk factor for future development of PD delusions. MATERIALS AND METHODS: We reviewed the detailed clinical chart of patients with PD without a history of psychosis who underwent [123I]FP-CIT SPECT during the disease. The endpoint was defined as when the delusions occurred during the 5 years after the examination of [123I]FP-CIT SPECT. Specific binding ratio (SBR) values were calculated. RESULTS: Sixty-one patients with PD were included in the analysis, and 11 patients had delusions within 5 years of [123I] FP-CIT SPECT. The average (p = 0.004), minimum (p = 0.004), maximum (p = 0.001), right-sided (p = 0.002), and left-sided (p = 0.003) SBRs in the striatum were significantly smaller in patients with delusions than in patients without delusions. Each difference of each SBR was significantly smaller than those without delusions after adjusting after controlling for age, gender, disease severity, timing of [123I]FP-CIT SPECT, anti-parkinsonian medications, hospitalization, administering more or newly anti-parkinsonian drugs, and receiving DBS or LCIG. CONCLUSIONS: PD delusions is still problematic, and lowering DAT binding may be helpful for predicting future delusions, regardless of the timing of [123I]FP-CIT SPECT.

Identification of three distinct cell populations for urate excretion in human kidneys.

In humans, uric acid is an end-product of purine metabolism. Urate excretion from the human kidney is tightly regulated by reabsorption and secretion. At least eleven genes have been identified as human renal urate transporters. However, it remains unclear whether all renal tubular cells express the same set of urate transporters. Here, we show renal tubular cells are divided into three distinct cell populations for urate handling. Analysis of healthy human kidneys at single-cell resolution revealed that not all tubular cells expressed the same set of urate transporters. Only 32% of tubular cells were related to both reabsorption and secretion, while the remaining tubular cells were related to either reabsorption or secretion at 5% and 63%, respectively. These results provide physiological insight into the molecular function of the transporters and renal urate handling on single-cell units. Our findings suggest that three different cell populations cooperate to regulate urate excretion from the human kidney, and our proposed framework is a step forward in broadening the view from the molecular to the cellular level of transport capacity.

The Lateralization of Resting Motor Threshold to Predict Medication-Mediated Improvement in Parkinson's Disease.

Cortical stimulation patterns in patients with Parkinson's disease (PD) are asymmetric and get altered over time. This study examined cortical neurophysiological markers for PD and identified neurophysiological markers for lateralization in PD. We used transcranial magnetic stimulation (TMS) to study corticospinal and intracortical excitability in 21 patients with idiopathic PD. We used the Movement Disorder Society Unified Parkinson's Disease Rating Scale for examination during on and off periods and evaluated inhibitory and facilitatory process markers using TMS, including resting motor thresholds (RMT), active motor thresholds, and motor evoked potential amplitude. The RMT in the more affected cortex was significantly shorter than in the less affected cortex, and was strongly correlated with improved motor function following medication. Patients in the tremor group exhibited significantly lower RMT compared to those in the akinetic-rigid group. Cortical electrophysiological laterality observed in patients with PD may be a useful marker for guiding treatment and identifying underlying compensatory mechanisms.

Case report: Unilateral masticatory atrophy caused by pure trigeminal motor neuropathy.

Pure trigeminal motor neuropathy (PTMN) is characterized by trigeminal motor weakness without signs of trigeminal sensory dysfunction or involvement of other cranial nerves. We describe a rare case of an 83-year-old man with weakness and atrophy of the right masticatory muscle without any sensory disturbance. Brain computed tomography and magnetic resonance imaging revealed atrophy and fatty infiltration of the right masticatory muscle. Electromyography revealed abnormal spontaneous activity, chronic neurogenic motor unit potentials, and reduced interference patterns in the right temporalis and the masseter muscles. The patient was diagnosed with PTMN based on the clinical symptoms and examinations. Our case presents a rare clinical manifestation with unclear etiology.

Neural synchronization analysis of electroencephalography coherence in patients with Parkinson's disease-related mild cognitive impairment.

Introduction: The underlying pathophysiology of slight cognitive dysfunction in Parkinson's disease-related mild cognitive impairment (PD-MCI) is yet to be elucidated. Our study aimed to evaluate the association between cognitive function and brain functional connectivity (FC) in patients with PD-MCI. Methods: Twenty patients with sporadic PD-MCI were evaluated for FC in the brain network. Further, electroencephalography (EEG) coherence analysis in the whole-brain and quantified regional coherence using phase coupling were performed for each frequency, and motor and cognitive function were assessed in the whole-brain. Results: The degree of cognitive impairment was related to a decrease in the coherence in the alpha ranges. The regional coherence in the left frontal-left parietal region rather than the right frontal-right parietal region showed a higher correlation with the cognitive function scores. Conclusion: The differences in EEG coherence across different types of cognitive dysfunction reflect a compensatory response to the heterogeneous and complex clinical presentation of PD-MCI. Our findings indicate decreased brain efficiency and impaired neural synchronization in PD-MCI; these results may be crucial in elucidating the pathological exacerbation of PD-MCI.

Pain-Related Abnormal Neuronal Synchronization of the Nucleus Accumbens in Parkinson's Disease.

Patients with Parkinson's disease (PD) often experience pain, which fluctuates in "on" and "off" states, but the underlying mechanism is unclear. The nucleus accumbens (NAc) is a central component of the mesolimbic dopaminergic pathway involved in pain processing. We conducted resting-state functional magnetic resonance imaging (rsfMRI) analysis to explore the relationship between the neuronal synchronization of NAc with pain-related brain regions and pain intensity in "on" and "off" states. We assessed 23 patients with sporadic PD based on rsfMRI and pain intensity using the revised Short-Form McGill Pain Questionnaire. Patients with PD displayed higher pain intensity scores in the "off" state than in the "on" state. The pain intensity in the "off" state was substantially correlated with the functional connectivity (FC) between the NAc and primary motor/sensory cortices and contralateral NAc. Changes in pain intensity from the "on" to "off" state displayed correlations with those between the right (rNA) and left NAc (lNAc) and the right precentral gyrus (rPreCG) /right insular cortex (rIC) from the "off" to "on" state. Aberrant bilateral NAc and rNAc-rPreCG/rIC FC in the "off" state were closely related to pain symptoms developed from the "on" to "off" states. These results suggest that the NAc in the mesolimbic pathway is related to pain in PD and may help understand the mechanism of pain development in patients with PD.

Feasibility and acceptability of novel functional electronic stimulated rehabilitation application for treatment in patients with cerebrovascular disorders: the FRAT study protocol.

BACKGROUND: The prognosis of patients with cerebrovascular disorders is poor owing to their high residual rate of hemiplegia. Delayed withdrawal from synkinesis is a major cause of prolonged hemiplegia; however, effective rehabilitation has not been established. This single-arm, open-label study aims to evaluate the influence of a low-frequency treatment device on canceling synkinesis in patients with incomplete paralysis and cerebrovascular disorders. METHODS: Eligible participants will include patients aged 20 years or older with incomplete paralysis, defined as upper limb Brunnstrom stage (BRS) of 2-4, who are within 1 month of onset of a cerebrovascular disorder. Qualified patients will be assigned to the novel rehabilitation treatment with IVES+ for 4 weeks. The primary endpoint of the study is the change from baseline in the upper-limb Fugl-Meyer Assessment (FMA) 2 weeks after the start of treatment. The secondary endpoints are changes in the amount of Functional Independence Measure, changes in the amount of upper-limb BRS, and changes in the amount of Barthel Index (BI) compared to the pre-intervention value at weeks 2 and 4; changes in the upper-limb FMA scores at 1, 3, and 4 weeks; changes in grip strength compared to the pre-intervention values at 1, 2, 3, and 4 weeks; and changes in upper-limb strength (manual muscle test) compared to the pre-intervention values at 1, 2, 3, and 4 weeks. DISCUSSION: This study will explore the usefulness of IVES+ for recovery from motor paralysis in patients with cerebrovascular disorders. TRIAL REGISTRATION: Japanese Clinical Registry, jRCTs052180226. Date of registration: February 1, 2022.

Neuronal Dynamics of Pain in Parkinson's Disease.

Pain is an important non-motor symptom of Parkinson's disease (PD). It negatively impacts the quality of life. However, the pathophysiological mechanisms underlying pain in PD remain to be elucidated. This study sought to use electroencephalographic (EEG) coherence analysis to compare neuronal synchronization in neuronal networks between patients with PD, with and without pain. Twenty-four patients with sporadic PD were evaluated for the presence of pain. Time-frequency and coherence analyses were performed on their EEG data. Whole-brain and regional coherence were calculated and compared between pain-positive and pain-negative patients. There was no significant difference in the whole-brain coherence between the pain-positive and pain-negative groups. However, temporal-temporal coherence differed significantly between the two groups (p = 0.031). Our findings indicate that aberrant synchronization of inter-temporal regions is involved in PD-related pain. This will further our understanding of the mechanisms underlying pain in PD.

Olig2-astrocytes express neutral amino acid transporter SLC7A10 (Asc-1) in the adult brain.

We have reported that the transcription factor Olig2 labels a subpopulation of astrocytes (Olig2-astrocytes), which show distribution patterns different from those of GFAP-expressing astrocytes (GFAP-astrocytes) in the adult brain. Here, to uncover the specific functions of Olig2-astrocytes, we first analyzed public single-cell RNA-seq databases of adult mouse brains. Unbiased classification of gene expression profiles and subsequent gene ontology analyses revealed that the majority of Olig2-astrocytes belonged to an astrocytic cluster that is enriched for transporter-related genes. SLC7A10 (also known as ASC-1) was one of the representative neutral amino acid transporter genes in the cluster. To complement the in silico data analyses, we differentially isolated Olig2- and GFAP-astrocytes from the same frozen section of the lateral globus pallidus using laser microdissection and compared their gene expression by quantitative reverse transcription PCR. We confirmed that Olig2 and GFAP mRNAs were preferentially expressed in the Olig2- and GFAP-astrocytes, respectively, indicating that the laser microdissection method yielded minimal cross-contamination between two types of cells. The Olig2-astrocytes expressed significantly higher levels of SLC7A10 mRNA than the GFAP-astrocytes, corroborating the in silico data. We next localized SLC7A10 protein by immunohistochemistry in the lateral globus pallidus, which was also genetically labeled for Olig2. SLC7A10 co-localized with Olig2-genetic labeling, especially on the fine processes of Olig2-astrocytes. These results are consistent with the recent discovery that SLC7A10 is expressed not only in neurons but also in a subset of astrocytes. Taken together, our findings suggest that SLC7A10 exerts specific functions in Olig2-astrocytes of the adult brain.

Gene Expression Profiles of Human Cerebral Organoids Identify PPAR Pathway and PKM2 as Key Markers for Oxygen-Glucose Deprivation and Reoxygenation.

Ischemic stroke is one of the most common neurological diseases. However, the impact of ischemic stroke on human cerebral tissue remains largely unknown due to a lack of ischemic human brain samples. In this study, we applied cerebral organoids derived from human induced pluripotent stem cells to evaluate the effect of oxygen-glucose deprivation/reoxygenation (OGD/R). Pathway analysis showed the relationships between vitamin digestion and absorption, fat digestion and absorption, peroxisome proliferator-activated receptor (PPAR) signaling pathway, and complement and coagulation cascades. Combinational verification with transcriptome and gene expression analysis of different cell types revealed fatty acids-related PPAR signaling pathway and pyruvate kinase isoform M2 (PKM2) as key markers of neuronal cells in response to OGD/R. These findings suggest that, although there remain some limitations to be improved, our ischemic stroke model using human cerebral organoids would be a potentially useful tool when combined with other conventional two-dimensional (2D) mono-culture systems.

Brainstem Organoids From Human Pluripotent Stem Cells.

The brainstem is a posterior region of the brain, composed of three parts, midbrain, pons, and medulla oblongata. It is critical in controlling heartbeat, blood pressure, and respiration, all of which are life-sustaining functions, and therefore, damages to or disorders of the brainstem can be lethal. Brain organoids derived from human pluripotent stem cells (hPSCs) recapitulate the course of human brain development and are expected to be useful for medical research on central nervous system disorders. However, existing organoid models are limited in the extent hPSCs recapitulate human brain development and hence are not able to fully elucidate the diseases affecting various components of the brain such as brainstem. Here, we developed a method to generate human brainstem organoids (hBSOs), containing midbrain/hindbrain progenitors, noradrenergic and cholinergic neurons, dopaminergic neurons, and neural crest lineage cells. Single-cell RNA sequence (scRNA-seq) analysis, together with evidence from proteomics and electrophysiology, revealed that the cellular population in these organoids was similar to that of the human brainstem, which raises the possibility of making use of hBSOs in investigating central nervous system disorders affecting brainstem and in efficient drug screenings.

Risk of Unsuccessful Noninvasive Ventilation for Acute Respiratory Failure in Heterogeneous Neuromuscular Diseases: A Retrospective Study.

If invasive ventilation can be avoided by performing noninvasive mechanical ventilation (NIV) in patients with acute respiratory failure (ARF), the disease can be effectively managed. It is important to clarify the characteristics of patients with neuromuscular diseases in whom initial NIV is likely to be unsuccessful. We studied 27 patients in stable neuromuscular condition who initially received NIV to manage fatal ARF to identify differences in factors immediately before the onset of ARF among patients who receive continuous NIV support, patients who are switched from NIV to invasive ventilation, and patients in whom NIV is discontinued. Endpoints were evaluated 24 and 72 hours after the initiation of NIV. After 24 hours, all but 1 patient with amyotrophic lateral sclerosis (ALS) received continuous NIV support. 72 hours later, 5 patients were switched from NIV to invasive ventilation, and 5 patients continued to receive NIV support. 72 hours after the initiation of NIV, the proportion of patients with a diagnosis of ALS differed significantly among the three groups (P=0.039). NIV may be attempted to manage acute fatal respiratory failure associated with neuromuscular diseases, but clinicians should carefully manage the clinical course in patients with ALS.