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2.
Neurol Ther ; 13(2): 323-338, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38227133

ABSTRACT

INTRODUCTION: A higher levodopa dose is a risk factor for motor complications in Parkinson's disease (PD). Istradefylline (IST) is used as adjunctive treatment to levodopa in PD patients with off episodes, but its impact on levodopa dose titration remains unclear. The objective of this study was to investigate the effect of IST on levodopa dose escalation in PD patients with wearing-off. METHODS: This was a multicenter, open-label, randomized, parallel-group controlled study (ISTRA ADJUST PD) in which PD patients experiencing wearing-off (n = 114) who were receiving levodopa 300-400 mg/day were randomized to receive IST or no IST (control). Levodopa dose was escalated according to clinical severity. The primary endpoint was cumulative additional levodopa dose, and secondary endpoints were changes in symptom rating scales, motor activity determined by a wearable device, and safety outcomes. RESULTS: The cumulative additional levodopa dose throughout 37 weeks and dose increase over 36 weeks were significantly lower in the IST group than in the control group (both p < 0.0001). The Movement Disorder Society Unified Parkinson's Disease Rating Scale Part I and device-evaluated motor activities improved significantly from baseline to 36 weeks in the IST group only (all p < 0.05). Other secondary endpoints were comparable between the groups. Adverse drug reactions (ADRs) occurred in 28.8% and 13.2% of patients in the IST and control groups, respectively, with no serious ADRs in either group. CONCLUSION: IST treatment reduced levodopa dose escalation in PD patients, resulting in less cumulative levodopa use. Adjunctive IST may improve motor function more objectively than increased levodopa dose in patients with PD. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs031180248.

3.
Brain Commun ; 5(2): fcad053, 2023.
Article in English | MEDLINE | ID: mdl-36938526

ABSTRACT

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. Our results indicate that patients with isolated cerebellar stroke were significantly less likely to experience the Poggendorff illusion effect than patients with isolated cerebral stroke or healthy controls (74.6, 90.5 and 89.8%, respectively; F(2,76) = 6.675, P = 0.002). However, there were no inter-group differences in the control tasks. Lesion-symptom mapping analysis revealed that the brain lesions associated with the reduced frequency of the Poggendorff illusion effect were mainly centred on the right posteromedial cerebellar region, including the right lobules VI, VII, VIII, IX and Crus II. Our findings demonstrated, for the first time, that patients with cerebellar damage were significantly less likely to experience the Poggendorff illusion effect and that right posteromedial cerebellar lesions played an important role in this effect. These results provide new insight into alterations of a geometric illusion effect in patients with cerebellar disorders and pave the way for future clinical use of the illusion task to detect cerebellar abnormalities.

4.
J Clin Exp Neuropsychol ; 44(1): 50-61, 2022 02.
Article in English | MEDLINE | ID: mdl-35658796

ABSTRACT

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. METHODS: We examined the relationship between motor learning ability and gambling propensity, a possible symptom for prodromal ICDs, in PD patients. Fifty-nine PD patients without clinical ICDs and 43 normal controls (NC) were administered a visuomotor rotation perturbation task and the Iowa Gambling Task (IGT) to evaluate motor learning ability and gambling propensity, respectively. Participants also performed additional cognitive assessments and underwent brain perfusion SPECT imaging. RESULTS: Better motor learning ability was significantly correlated with lower IGT scores, i.e., higher gambling propensity, in PD patients but not in NC. The higher scores on assessments reflecting prefrontal lobe function and well-preserved blood perfusion in prefrontal areas were correlated with lower IGT scores along with better motor learning ability. CONCLUSIONS: Our findings suggest that better motor learning ability and higher gambling propensity are based on better prefrontal functions, which are in accordance with the theory that the prefrontal cortex is one of the common essential regions for both motor learning and ICDs.


Subject(s)
Disruptive, Impulse Control, and Conduct Disorders , Gambling , Parkinson Disease , Gambling/diagnostic imaging , Gambling/psychology , Humans , Parkinson Disease/complications , Parkinson Disease/diagnostic imaging , Prefrontal Cortex
5.
BMC Neurol ; 22(1): 71, 2022 Mar 03.
Article in English | MEDLINE | ID: mdl-35241003

ABSTRACT

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. Istradefylline, an adenosine A2A receptor antagonist indicated as an adjunctive treatment to levodopa-containing preparations in PD patients experiencing wearing off, is currently available in Japan and the US. Preclinical and preliminary clinical data suggested that adjunctive istradefylline may provide sustained antiparkinsonian benefits without a levodopa dose increase; however, available data on the impact of istradefylline on levodopa dose titration are limited. The ISTRA ADJUST PD study will evaluate the effect of adjunctive istradefylline on levodopa dosage titration in PD patients. METHODS: This 37-week, multicenter, randomized, open-label, parallel-group controlled study in PD patients aged 30-84 years who are experiencing the wearing-off phenomenon despite receiving levodopa-containing medications ≥ 3 times daily (daily dose 300-400 mg) began in February 2019 and will continue until February 2022. Enrollment is planned to attain 100 evaluable patients for the efficacy analyses. Patients will receive adjunctive istradefylline (20 mg/day, increasing to 40 mg/day) or the control in a 1:1 ratio, stratified by age, levodopa equivalent dose, and presence/absence of dyskinesia. During the study, the levodopa dose will be increased according to symptom severity. The primary study endpoint is the comparison of the cumulative additional dose of levodopa-containing medications during the treatment period between the adjunctive istradefylline and control groups. Secondary endpoints include changes in efficacy rating scales and safety outcomes. DISCUSSION: This study aims to clarify whether adjunctive istradefylline can reduce the cumulative additional dose of levodopa-containing medications in PD patients experiencing the wearing-off phenomenon, and lower the risk of levodopa-associated complications. It is anticipated that data from ISTRA ADJUST PD will help inform future clinical decision-making for patients with PD in the real-world setting. TRIAL REGISTRATION: Japan Registry of Clinical Trials, jRCTs031180248 ; registered 12 March 2019.


Subject(s)
Levodopa , Parkinson Disease , Adenosine A2 Receptor Antagonists/pharmacology , Adenosine A2 Receptor Antagonists/therapeutic use , Adult , Aged , Aged, 80 and over , Antiparkinson Agents/therapeutic use , Humans , Levodopa/adverse effects , Middle Aged , Multicenter Studies as Topic , Parkinson Disease/drug therapy , Purines/pharmacology , Purines/therapeutic use , Randomized Controlled Trials as Topic
6.
Front Neurol ; 12: 751750, 2021.
Article in English | MEDLINE | ID: mdl-34690919

ABSTRACT

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 (PrPres) 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. Presymptomatic CJD is currently impossible to diagnose because of the lack of established early diagnostic markers. However, since MRI is increasingly used in daily clinical practice, the chance detection of such DWI abnormalities would have important implications in terms of providing a clue to examine a highly specific early diagnostic marker to be developed in the future for CJD. This will allow presymptomatic intervention by disease-modifying therapy in the near future.

7.
J Parkinsons Dis ; 11(4): 2005-2016, 2021.
Article in English | MEDLINE | ID: mdl-34366367

ABSTRACT

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. OBJECTIVE: This study aimed to investigate the relative diagnostic accuracy of qualitative (clustering and switching) verbal fluency strategies and their correlates with functional imaging in PD-MCI. METHODS: Forty-five patients with PD (26 with MCI and 19 without MCI) and 25 healthy controls underwent comprehensive neurocognitive testing and resting-state functional magnetic resonance imaging. MCI in patients with PD was diagnosed according to established clinical criteria. The diagnostic accuracy of verbal fluency measures was determined via receiver operating characteristic analysis. Changes in brain functional connectivity between groups and across clinical measures were assessed using seed-to-voxel analyses. RESULTS: Patients with PD-MCI generated fewer words and switched less frequently in semantic and phonemic fluency tasks compared to other groups. Switching in semantic fluency showed high diagnostic accuracy for PD-MCI and was associated with reduced functional connectivity in the salience network. CONCLUSION: Our results indicate that reduced switching in semantic fluency tasks is a sensitive and specific marker for PD-MCI. Qualitative verbal fluency deficits and salience network dysfunction represent early clinical changes observed in PD-MCI.


Subject(s)
Cognitive Dysfunction , Parkinson Disease , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/etiology , Executive Function , Humans , Neuroimaging , Neuropsychological Tests , Parkinson Disease/complications , Parkinson Disease/diagnostic imaging
8.
Neuroimage Clin ; 31: 102760, 2021.
Article in English | MEDLINE | ID: mdl-34274725

ABSTRACT

BACKGROUND: Foreign accent syndrome (FAS) is a rare acquired speech disorder wherein an individual's spoken accent is perceived as "foreign." Most reported cases involve left frontal brain lesions, but it is known that various other lesions can also cause FAS. To determine whether heterogeneous FAS-causing lesions are localized to a common functional speech network rather than to a single anatomical site, we employed a recently validated image analysis technique known as "lesion network mapping." METHODS: We identified 25 published cases of acquired neurogenic FAS without aphasia, and mapped each lesion volume onto a reference brain. We next identified the network of brain regions functionally connected to each FAS lesion using a connectome dataset from normative participants. Network maps were then overlapped to identify common network sites across the lesions. RESULTS: Classical lesion overlap analysis showed heterogeneity in lesion anatomical location, consistent with prior reports. However, at least 80% of lesions showed network overlap in the bilateral lower and middle portions of the precentral gyrus and in the medial frontal cortex. The left lower portion of the precentral gyrus is suggested to be the location of lesions causing apraxia of speech (AOS), and the middle portion is considered to be a larynx-specific motor area associated with the production of vowels and stop/nasal consonants and with the determination of pitch accent. CONCLUSIONS: The lesions that cause FAS are anatomically heterogeneous, but they share a common functional network located in the bilateral posterior region of the frontal lobe. This network specifically includes not only the lower portion of the central gyrus, but also its middle region, which is referred to as the larynx motor cortex and is known to be associated with phonation. Our findings suggest that disrupted networks in FAS might be anatomically different from those in AOS.


Subject(s)
Aphasia , Motor Cortex , Brain/diagnostic imaging , Humans , Magnetic Resonance Imaging , Speech Disorders , Syndrome
9.
Neurobiol Aging ; 97: 147.e1-147.e9, 2021 01.
Article in English | MEDLINE | ID: mdl-32771225

ABSTRACT

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. We identified 21 patients with 18 rare variants, such that 1, 9, and 11 patients were homozygous, heterozygous, and compound heterozygous, respectively, with respect to PLA2G6 variants. The allele frequency was approximately equal between patients with familial PD and those with sporadic PD. The PLA2G6 variants detected frequently were identified in the early-onset sporadic PD group. Patients who were homozygous for a variant showed more severe symptoms than those who were heterozygous for the variant. The most common variant was p.R635Q in our cohort, which was considered a risk variant for PD. Thus, the variants of PLA2G6 may play a role in familial PD and early-onset sporadic PD.


Subject(s)
Gene Frequency/genetics , Genetic Association Studies , Genetic Predisposition to Disease/genetics , Genetic Variation , Group VI Phospholipases A2/genetics , Parkinson Disease/genetics , Adult , Age of Onset , Aged , Cohort Studies , Female , Heterozygote , Homozygote , Humans , Japan/epidemiology , Male , Middle Aged , Parkinson Disease/epidemiology
10.
J Infect Chemother ; 26(8): 865-869, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32405245

ABSTRACT

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 (64.3%), cough (54.3%), and general fatigue (24.3%). Forty-three patients (61.4%) had pneumonia. Higher body temperature, heart rate, and respiratory rate as well as higher of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and C-reactive protein (CRP) levels and lower serum albumin level and lymphocyte count were associated with the presence of pneumonia. Ground-glass opacity was found in 97.7% of the patients with pneumonia. Patients were administered neuraminidase inhibitors (20%), lopinavir/ritonavir (32.9%), and ciclesonide inhalation (11.4%). Mechanical ventilation and veno-venous extracorporeal membrane oxygenation was performed on 14 (20%) and 2 (2.9%) patients, respectively; two patients died. The median duration of intubation was 12 days. The patients with COVID-19 transferred to local hospitals during the outbreak had severe conditions and needed close monitoring. The severity of COVID-19 depends on the presence of pneumonia. High serum LDH, AST and CRP levels and low serum albumin level and lymphocyte count were found to be predictors of pneumonia. It was challenging for local hospitals to admit and treat these patients during the outbreak of COVID-19. Assessment of severity was crucial to manage a large number of patients.


Subject(s)
Betacoronavirus , Coronavirus Infections/physiopathology , Coronavirus Infections/therapy , Disease Outbreaks , Pneumonia, Viral/physiopathology , Pneumonia, Viral/therapy , Aged , COVID-19 , Coronavirus Infections/complications , Diabetes Complications/complications , Female , Humans , Hypertension/complications , Japan , Male , Middle Aged , Pandemics , Patient Acuity , Pneumonia, Viral/complications , Pneumonia, Viral/virology , Prognosis , SARS-CoV-2 , Ships
11.
J Hum Genet ; 65(9): 771-781, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32398759

ABSTRACT

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.R1441G, p.R1441H, p.G2019S, and p.I2020T. Herein, we obtained data containing LRRK2 variants derived from 1402 patients with PD (653 with sporadic PD and 749 with familial PD). As a result, we successfully detected pathogenic variants (four with p.R1441G, five with p.R1441H, seven with p.G2019S, and seven with p.I2020T) and other rare variants (two with p.V1447M, one with p.V1450I, one with p.T1491delT, and one with p.H2391Q). Two risk variants, p.P1446L and p.G2385R, were found in 10 and 146 patients, respectively. Most of the patients presented the symptoms resembling a common type of PD, such as middle-aged onset, tremor, akinesia, rigidity, and gait disturbance. Dysautonomia, cognitive decline, and psychosis were rarely observed. Each known pathogenic variant had a different founder in our cohort proven by haplotype analysis. The generation study revealed that the LRRK2 variants p.G2019S and p.I2020T were derived 3500 and 1300 years ago, respectively. Our findings present overviews of the prevalence and distribution of LRRK2 variants in Japanese cohorts.


Subject(s)
Genetic Predisposition to Disease/genetics , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/genetics , Parkinson Disease/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Child , Cohort Studies , Demography , Exons , Female , Genetic Variation , Haplotypes , Humans , Japan , Male , Middle Aged , Mutation , Parkinson Disease/mortality , Parkinson Disease/physiopathology , Pedigree , alpha-Synuclein/genetics
12.
No Shinkei Geka ; 47(10): 1037-1043, 2019 Oct.
Article in Japanese | MEDLINE | ID: mdl-31666419

ABSTRACT

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. We examined the relationship between DBS device-related infection and the following items:duration of electrode placement surgery, total number of tracks of microelectrode recordings(MER), period between surgeries, highest body temperature until implantable pulse generator(IPG)implantation, and patient background characteristics. RESULTS: Four(5.0%)patients developed device-related infection after DBS surgery. Three of them required device removal, whereas one improved following antibiotic treatment alone. We did not identify any specific trend or risk factor for infection. DISCUSSION: We perform DBS surgery in two stages. Patients were implanted with an IPG 2-3 days after electrode placement until August 2016, and at 6-8 days starting in September 2016. All cases of infection developed before September 2016, and no cases of infection have occurred since September 2016. We believe that lengthy surgical electrode placement affects the general status of patients and performing surgery before stabilization might confer a risk of infection. CONCLUSION: Device-related infection after DBS surgery does not seem to be associated with any risk factors. However, a shorter period between two-staged surgeries might affect infection rates.


Subject(s)
Deep Brain Stimulation , Anti-Bacterial Agents , Electrodes, Implanted , Humans , Retrospective Studies , Risk Factors
13.
Front Neurol ; 10: 1317, 2019.
Article in English | MEDLINE | ID: mdl-31920938

ABSTRACT

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. His motor features dramatically improved after the operation; however, he developed dysarthria and a refractory wheeze associated with dyspnea due to abnormal hyperadduction of the false vocal fold. By adjusting the stimulation site of STN, his severe wheeze, which was considered to be the result of the unfavorable spread of current to the corticobulbar tract, was significantly improved. This report provides concrete evidence that wheezing is caused by hyperadduction of the false vocal fold as an adverse effect of STN-DBS and can be reversed by adjusting the stimulation site for STN-DBS.

14.
Front Neurol ; 9: 375, 2018.
Article in English | MEDLINE | ID: mdl-29904367

ABSTRACT

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. This difference implies distinct neuronal mechanisms for phasic and tonic symptoms in the underlying cortico-basal ganglia neuronal network. Phasic symptoms are related to the pallido-thalamo-cortical pathway. The pathway related to tonic symptoms has been assumed to be different from that for phasic symptoms. In the present study, local field potentials of the globus pallidus internus (GPi) and globus pallidus externus (GPe) and electroencephalograms from the motor cortex (MCx) were recorded in 19 dystonia patients to analyze the differences between the two types of symptoms. The 19 patients were divided into two groups, 10 with predominant phasic symptoms (phasic patients) and 9 with predominant tonic symptoms (tonic patients). To investigate the distinct features of oscillations and functional couplings across the GPi, GPe, and MCx by clinical phenotype, power and coherence were calculated over the delta (2-4 Hz), theta (5-7 Hz), alpha (8-13 Hz), and beta (14-35 Hz) frequencies. In phasic patients, the alpha spectral peaks emerged in the GPi oscillatory activities, and alpha GPi coherence with the GPe and MCx was higher than in tonic patients. On the other hand, delta GPi oscillatory activities were prominent, and delta GPi-GPe coherence was significantly higher in tonic than in phasic patients. However, there was no significant delta coherence between the GPi/GPe and MCx in tonic patients. These results suggest that different pathophysiological cortico-pallidal oscillations are related to tonic and phasic symptoms.

15.
J Neurol Sci ; 385: 99-104, 2018 02 15.
Article in English | MEDLINE | ID: mdl-29406924

ABSTRACT

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). All subjects underwent 1.5-T MRI examinations, and WMH detected by T2-weighted images or fluid-attenuated inversion recovery images were semiquantified according to the Fazekas method. Medial temporal lobe atrophy (MTA) was visually assessed by the MTA score. RESULTS: WMH were more prominent in AD, DLB, and PDD patients than in PDND patients and normal controls (NCs). DLB as well as AD showed more severe WMH than PDD. Visual assessment of medial temporal lobe atrophy showed that AD patients had the most severe atrophy, followed by DLB, PDD, and PDND patients, and NC subjects in that order. MTA scores showed significant correlations with WMH severity. CONCLUSION: Our results indicated that DLB was more similar to AD than to PDD in terms of MRI findings, suggesting that WMH in DLB may reflect mainly AD-related pathology rather than atherosclerotic cerebrovascular changes.


Subject(s)
Alzheimer Disease/complications , Leukoencephalopathies/diagnostic imaging , Leukoencephalopathies/etiology , Lewy Body Disease/complications , Magnetic Resonance Imaging/methods , Parkinson Disease/complications , Supranuclear Palsy, Progressive/complications , Aged , Aged, 80 and over , Alzheimer Disease/diagnostic imaging , Case-Control Studies , Female , Humans , Image Processing, Computer-Assisted , Lewy Body Disease/diagnostic imaging , Male , Outpatients , Parkinson Disease/diagnostic imaging , Retrospective Studies , Supranuclear Palsy, Progressive/diagnostic imaging , Temporal Lobe/diagnostic imaging
16.
PLoS One ; 11(11): e0166861, 2016.
Article in English | MEDLINE | ID: mdl-27861638

ABSTRACT

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. In our study, we investigated the patterns of distribution and propagation of forebrain neurons expressing α-syn in aged macaques. It was found that the occurrence of α-syn-positive neurons proceeded topologically based on the midbrain dopamine pathways arising from the substantia nigra and the ventral tegmental area where they were primarily observed. In the nigrostriatal or mesolimbic dopamine pathway, the age-dependent increase in α-syn-positive neurons was evident in the striatum or the nucleus accumbens, respectively. Concerning the nigrostriatal pathway, a mediolateral or rostrocaudal gradient was seen in the substantia nigra or the striatum, respectively, and a compensatory increase in dopamine transporter occurred in the striatum regardless of the decreased dopamine level. In the mesocortical dopamine pathway, α-syn-positive neurons appeared in the prefrontal and then motor areas of the frontal lobe. Given that neither LB formation nor clinical phenotype manifestation was detected in any of the monkeys examined in the present study, aged macaques may be useful as a potential presymptomatic model for PD and LB-related neuropsychiatric disorders.


Subject(s)
Gene Expression , Neurons/metabolism , Prosencephalon/cytology , Prosencephalon/metabolism , alpha-Synuclein/genetics , Age Factors , Animals , Cell Count , Dopamine/metabolism , Dopaminergic Neurons/metabolism , Female , Frontal Lobe/cytology , Frontal Lobe/metabolism , Immunohistochemistry , Macaca , Male , Phosphorylation , Prosencephalon/pathology , Substantia Nigra/metabolism , Tyrosine 3-Monooxygenase/genetics , Tyrosine 3-Monooxygenase/metabolism , alpha-Synuclein/metabolism
17.
Front Hum Neurosci ; 10: 131, 2016.
Article in English | MEDLINE | ID: mdl-27064969

ABSTRACT

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. Alpha and beta desynchronizations were observed in bilateral STNs at the onset of both VMC and VMR tasks. On the other hand, theta and gamma synchronizations were prominent in bilateral STNs specifically at the onset of the VMC task. In particular, just after VMC, theta functional coupling between the bilateral STNs increased, and the theta phase became coupled to the gamma amplitude within the contralateral STN in a phase-amplitude cross-frequency coupled manner. On the other hand, the prominent beta-gamma cross-frequency couplings observed in the bilateral STNs at rest were reduced by the VMC and VMR tasks. These results suggest that STNs are bilaterally involved in the different performances of muscle contraction and relaxation through the theta-gamma and beta-gamma networks between bilateral STNs in patients with PD.

18.
Clin Neurophysiol ; 126(10): 1941-50, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25591829

ABSTRACT

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. RESULTS: Significant coherence in the sub-beta and beta frequency bands was simultaneously observed between the STN and contralateral STN (STN-cSTN), the STN and ipsilateral MCx (STN-iMCx), and the STN and contralateral MCx (STN-cMCx). In each patient, the frequency of the peak STN-cSTN coherence was similar to that of the peak STN-iMCx and STN-cMCx coherence. The causality between the STN and MCx was strongest in the one-way direction from the MCx to the ipsilateral STN. CONCLUSIONS: Abnormal oscillations in the STN in the sub-beta and beta bands were functionally coupled among bilateral STN and MCx at the eigen-frequency in individual patients with PD. SIGNIFICANCE: Synchronized activity through cortico-subcortical transmission may have an important role in the pathophysiology of PD.


Subject(s)
Beta Rhythm , Motor Cortex/physiopathology , Parkinson Disease/diagnosis , Parkinson Disease/physiopathology , Subthalamic Nucleus/physiopathology , Aged , Beta Rhythm/physiology , Electroencephalography/methods , Female , Humans , Male , Middle Aged
19.
Case Rep Neurol Med ; 2014: 937095, 2014.
Article in English | MEDLINE | ID: mdl-24716024

ABSTRACT

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. Her severe and medically intractable symptoms were alleviated by bilateral deep brain stimulation of the globus pallidus internus, with myoclonus and dystonia scores showing 70% improvement after the surgery compared to presurgical scores. This is the first report of a genetically confirmed case of DYT11 in Japan. This paper together with other recent reports collectively demonstrates that DYT11 patients are distributed worldwide, including Asia. Thus, a diagnosis of DYT11 should be considered when clinicians encounter a patient with childhood-onset myoclonus and/or dystonia with psychiatric symptoms, regardless of ethnic background.

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