Publications by authors named "Katsuo Kimura"

Article Synopsis
  • Istradefylline (IST) is investigated as an adjunctive treatment for Parkinson's disease (PD) to see if it can reduce the need for higher doses of levodopa, which is commonly linked to motor complications.
  • In a study with 114 PD patients experiencing wearing-off symptoms, those receiving IST required significantly less additional levodopa over 37 weeks compared to those who did not receive IST.
  • Patients treated with IST also showed improvements in motor functions measured by rating scales and wearable devices, suggesting that IST may enhance symptom management without increasing levodopa dosage significantly.
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This study aimed to test our hypothesis that the cerebellum plays an important role in the generation of the optical-geometric illusion known as the Poggendorff illusion, the mechanism of which has been explained by accumulated experience with natural scene geometry. A total of 79 participants, comprising 28 patients with isolated cerebellar stroke, 27 patients with isolated cerebral stroke and 24 healthy controls, performed Poggendorff illusion tasks and 2 different control tasks. We also investigated core brain regions underpinning changes in the experience of the illusion effect using multivariate lesion-symptom mapping.

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Introduction: The basal ganglia and related dopaminergic cortical areas are important neural systems underlying motor learning and are also implicated in impulse control disorders (ICDs). Motor learning impairments and ICDs are frequently observed in Parkinson's disease (PD). Nevertheless, the relationship between motor learning ability and ICDs has not been elucidated.

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Background: Levodopa remains the most effective symptomatic treatment for Parkinson's disease (PD) more than 50 years after its clinical introduction. However, the onset of motor complications can limit pharmacological intervention with levodopa, which can be a challenge when treating PD patients. Clinical data suggest using the lowest possible levodopa dose to balance the risk/benefit.

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The diagnosis of presymptomatic Creutzfeldt-Jakob disease (CJD) is challenging. The levels of total tau protein, 14-3-3 protein, and protease-resistant isoform of prion protein (PrP) in the cerebrospinal fluid; periodic sharp wave complexes on electroencephalography; and diffusion-weighted imaging (DWI) of brain magnetic resonance imaging (MRI) have all been used to diagnose symptomatic CJD, but none of these markers have been established in the diagnosis of presymptomatic CJD. Here, we report a case of genetic CJD with the V180I mutation in which a small punctate cortical hyperintensity was detected on DWI 6 months before symptom onset and 9 months before diagnosis.

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Background: Mild cognitive impairment (MCI) in Parkinson's disease (PD) is considered a risk factor for PD with dementia (PDD). Verbal fluency tasks are widely used to assess executive function in PDD. However, in cases of PD with MCI (PD-MCI), the relative diagnostic accuracy of different qualitative verbal fluency measures and their related neural mechanisms remain unknown.

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Article Synopsis
  • Foreign Accent Syndrome (FAS) is a rare speech disorder where people suddenly speak with a foreign accent due to brain lesions, primarily in the left frontal region.
  • A research study mapped the brain lesions from 25 FAS cases and identified a shared functional network of connected brain regions despite the varied anatomical locations of these lesions.
  • The findings suggest that while the actual brain lesions causing FAS can differ, they consistently disrupt a specific functional network in the bilateral posterior frontal lobe, which is related to speech production and phonation.
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This study aimed to evaluate genotype-phenotype correlations of Parkinson's disease (PD) patients with phospholipase A2 group V (PLA2G6) variants. We analyzed the DNA of 798 patients with PD, including 78 PD patients reported previously, and 336 in-house controls. We screened the exons and exon-intron boundaries of PLA2G6 using the Ion Torrent system and Sanger method.

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We investigated the clinical course of individuals with 2019 novel coronavirus disease (COVID-19) who were transferred from the Diamond Princess cruise ship to 12 local hospitals. The conditions and clinical courses of patients with pneumonia were compared with those of patients without pneumonia. Among 70 patients (median age: 67 years) analyzed, the major symptoms were fever (64.

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Variants of leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of familial Parkinson's disease (PD). We aimed to investigate the genetic and clinical features of patients with PD and LRRK2 variants in Japan by screening for LRRK2 variants in three exons (31, 41, and 48), which include the following pathogenic mutations: p.R1441C, p.

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Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for motor features in Parkinson's disease (PD). We present the case of a 56-year-old man with a 17-year history of PD. He underwent bilateral STN-DBS at the age of 51 years because of troublesome dyskinesia and wearing off.

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Background: Device-related infection frequently becomes a serious problem after deep brain stimulation(DBS)surgery and DBS device removal is usually the only effective treatment option. In this study, we examined risk factors for infection related to DBS devices at our institution.

Methods: We retrospectively investigated 80 DBS surgeries performed between March 2009 and September 2017 at our institution.

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Pallidal deep brain stimulation (DBS) improves the symptoms of dystonia. The improvement processes of dystonic movements (phasic symptoms) and tonic symptoms differ. Phasic symptoms improve rapidly after starting DBS treatment, but tonic symptoms improve gradually.

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Background: In dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD), it is still debated whether white matter hyperintensities (WMH) on MRI reflect atherosclerotic cerebrovascular changes or Alzheimer's disease (AD)-related pathology such as cerebral amyloid angiopathy. To examine AD-related pathology in DLB and PDD, we compared the severity of WMH and medial temporal lobe atrophy among patients with DLB, PDD, non-demented PD (PDND), and AD.

Methods: We retrospectively studied sex- and age-matched outpatients with AD, DLB, PDD, and PDND, as well as subjects without central nervous system disorders as normal controls (n=50 each).

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In neurodegenerative disorders, such as Parkinson's disease (PD), alpha-synuclein (α-syn) accumulates to induce cell death and/or form a cytoplasmic inclusion called Lewy body (LB). This α-syn-related pathology is termed synucleinopathy. It remains unclear how α-syn accumulation expands during the progress of synucleinopathy in the human brain.

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The volitional control of muscle contraction and relaxation is a fundamental component of human motor activity, but how the processing of the subcortical networks, including the subthalamic nucleus (STN), is involved in voluntary muscle contraction (VMC) and voluntary muscle relaxation (VMR) remains unclear. In this study, local field potentials (LFPs) of bilateral STNs were recorded in patients with Parkinson's disease (PD) while performing externally paced VMC and VMR tasks of the unilateral wrist extensor muscle. The VMC- or VMR-related oscillatory activities and their functional couplings were investigated over the theta (4-7 Hz), alpha (8-13 Hz), beta (14-35 Hz), and gamma (40-100 Hz) frequency bands.

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Objective: It has been suggested that abnormal synchronization and oscillation of neuronal activity in the subthalamic nucleus (STN) is associated with sensorimotor dysfunction in Parkinson's disease (PD). We investigated the bilateral subcortico-cortical functional coupling in PD patients.

Methods: We simultaneously recorded local field potentials from the bilateral STN using electrodes inserted for deep brain stimulation and electroencephalograms from the bilateral motor cortices (MCx) in 11 patients at rest, and analyzed their coherences and causalities.

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We describe the case of a 42-year-old Japanese woman with childhood-onset myoclonus, dystonia, and psychiatric symptoms, including anxiety, phobia, and exaggerated startle response. The diagnosis was confirmed as myoclonus-dystonia (DYT11) by identifying a mutation in the gene encoding ε -sarcoglycan. Interestingly, while motor-related symptoms in DYT11 generally improve with alcohol ingestion, the patient's symptoms were exacerbated by alcohol intake.

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