Publications by authors named "Atsuko Mori"

34 Publications

Biomass energy, particulate matter (PM), and the prevalence of chronic obstructive pulmonary disease (COPD) among Congolese women living near of a cement plant, in Kongo Central Province.

Environ Sci Pollut Res Int 2020 Nov 15;27(32):40706-40714. Epub 2020 Jul 15.

Department of Environmental Medicine, Kochi University Kochi Medical School, Oko-cho Kohasu, Nankoku, Kochi, 783-8505, Japan.

This study investigated whether the individual and combined effects of using biomass energy and living in the neighborhood of a cement plant were associated with the risk of COPD and respiratory symptoms among Congolese women. A total of 235 women from two neighborhood communities of a cement plant participated in this cross-sectional study. Participants were classified into the more exposed group (MEG = 137) and a less exposed group (LEG = 98), as well as into biomass users (wood = 85, charcoal = 49) or electricity users (101 participants). Participants completed a questionnaire including respiratory symptoms, sociodemographic factors, medical history, lifestyle, and household characteristics. In addition to spirometry performance, outdoor PM (μg/m) was measured. Afternoon outdoor PM concentration was significantly higher in MEG than LEG (48.8 (2.5) μg/m vs 42.5 (1.5) μg/m). Compared to electricity users, wood users (aOR: 2.6, 95%CI 1.7; 5.9) and charcoal users (aOR: 2.9, 95%CI 1.4; 10.7) were at risk of developing airflow obstruction. Combined effects of biomass use and living in the neighborhood of a cement plant increased the risk of COPD in both wood users (aOR: 4, 95%CI 1.3; 12.2) and charcoal users (aOR: 3.1, 95%CI 1.7; 11.4). Exposure to biomass energy is associated with an increased risk of COPD. In addition, combined exposure to biomass and living near a cement plant had additive effects on COPD.
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http://dx.doi.org/10.1007/s11356-020-10099-2DOI Listing
November 2020

Texture analysis of sonographic muscle images can distinguish myopathic conditions.

J Med Invest 2019 ;66(3.4):237-247

Department of Neurology, Tokushima University, Tokushima, Japan.

Given the recent technological advent of muscle ultrasound (US), classification of various myopathic conditions could be possible, especially by mathematical analysis of muscular fine structure called texture analysis. We prospectively enrolled patients with three neuromuscular conditions and their lower leg US images were quantitatively analyzed by texture analysis and machine learning methodology in the following subjects :  Inclusion body myositis (IBM) [N=11] ; myotonic dystrophy type 1 (DM1) [N=19] ; polymyositis/dermatomyositis (PM-DM) [N=21]. Although three-group analysis achieved up to 58.8% accuracy, two-group analysis of IBM plus PM-DM versus DM1 showed 78.4% accuracy. Despite the small number of subjects, texture analysis of muscle US followed by machine learning might be expected to be useful in identifying myopathic conditions. J. Med. Invest. 66 : 237-240, August, 2019.
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http://dx.doi.org/10.2152/jmi.66.237DOI Listing
June 2020

PMP22-related disease: A novel splice site acceptor variant and intrafamilial phenotype variability.

Neuromuscul Disord 2019 06 28;29(6):422-426. Epub 2019 Mar 28.

Department of Clinical Neuroscience, Tokushima University Graduate School, Tokushima, Japan.

PMP22 is the most frequent mutated gene in Charcot-Marie-Tooth disease (CMT) type 1A. Another phenotype, hereditary neuropathy with pressure palsies (HNPP), could be caused by PMP22 mutations. PMP22 encodes a peripheral myelin protein with molecular weight 22-kDa. Various pathomechanisms have been postulated in PMP22-related disease, including dysfunction due to missense mutations, and alteration of a gene dose due to duplication/deletion mutations. We identified a novel PMP22 splice site acceptor variant, c.179-1G>A, in a patient with adult-onset chronic generalized polyneuropathy and two asymptomatic family members. Pathophysiological features of the members mainly overlapped with those reported in HNPP, but broad intrafamilial clinical variations were observed. PMP22 transcripts lacking of exon 4 were produced by the variant, presumably leading to in-frame deletion of 47 amino acids. The variant was also shown to exert effect on dosage of PMP22 mRNA. The complex molecular pathology would lead to the unique clinical and pathophysiological conditions.
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http://dx.doi.org/10.1016/j.nmd.2019.03.010DOI Listing
June 2019

Deep learning for waveform identification of resting needle electromyography signals.

Clin Neurophysiol 2019 05 23;130(5):617-623. Epub 2019 Feb 23.

Department of Neurology, Tokushima University, Tokushima, Japan.

Objective: Given the recent advent in machine learning and artificial intelligence on medical data analysis, we hypothesized that the deep learning algorithm can classify resting needle electromyography (n-EMG) discharges.

Methods: Six clinically observed resting n-EMG signals were used as a dataset. The data were converted to Mel-spectrogram. Data augmentation was then applied to the training data. Deep learning algorithms were applied to assess the accuracies of correct classification, with or without the use of pre-trained weights for deep-learning networks.

Results: While the original data yielded the accuracy up to 0.86 on the test dataset, data-augmentation up to 200,000 training images showed significant increase in the accuracy to 1.0. The use of pre-trained weights (fine tuning) showed greater accuracy than "training from scratch".

Conclusions: Resting n-EMG signals were successfully classified by deep-learning algorithm, especially with the use of data augmentation and transfer learning techniques.

Significance: Computer-aided signal identification of clinical n-EMG testing might be possible by deep-learning algorithms.
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http://dx.doi.org/10.1016/j.clinph.2019.01.024DOI Listing
May 2019

Distinct Incidence of Takotsubo Syndrome Between Amyotrophic Lateral Sclerosis and Synucleinopathies: A Cohort Study.

Front Neurol 2018 13;9:1099. Epub 2018 Dec 13.

Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.

Takotsubo syndrome (TTS) is an acute cardiac syndrome characterized by regional left ventricular dysfunction with a peculiar circumferential pattern, which typically results in apical ballooning. Evidence indicates a pivotal role of catecholamines in TTS, and researchers have discussed multiple hypotheses on the etiology, including multivessel coronary spasm, myocardial stunning, excessive transient ventricular afterload, and cardiac sympathetic overactivity with local noradrenaline spillover. Although central nervous system disorders, such as stroke and epilepsy, are known to trigger TTS, the incidence and clinical features of TTS in neurodegenerative disorders are poorly understood. Here, we retrospectively examined TTS cases in a single-center cohort composed of 250 patients with amyotrophic lateral sclerosis (ALS) and 870 patients with synucleinopathies [582 patients with Parkinson's disease (PD), 125 patients with dementia with Lewy bodies (DLB), and 163 patients with multiple system atrophy (MSA)] and identified 4 (1.6%, including 2 women) cases with ALS and no cases with synucleinopathies. Two ALS patients underwent autopsy and the pathological findings were compatible with the chronological changes identified in catecholamine-induced cardiomyopathy. A literature review identified 16 TTS cases with ALS, 1 case each with PD and DLB, and no cases with MSA. When current and previous TTS cases with ALS were concatenated: 55% (11/20) were female; 35% (7/20) had a bulbar-onset and 45% (9/20) had a limb-onset; the mean age of TTS onset was 63.3 ± 9.0 years and the mean interval time from ALS onset to TTS development was 4.9 ± 3.0 years; no (0/16) patients developed TTS within 12 months after ALS onset; 50% (10/20) underwent artificial ventilations; the mortality was 17% (3/18); and most cases had precipitating factors, and TTS development was associated with gastrostomy, tracheostomy, or infections in 45% (9/20) of the patients. This study demonstrated that ALS is a considerable predisposing factor of TTS and that synucleinopathies rarely cause TTS. The distinct TTS incidence between ALS and synucleinopathies may be due to cardiac sympathetic overactivity in ALS and may also be affected by cardiac sympathetic denervation in synucleinopathies. Moreover, the etiology of TTS in ALS may be reasonably explained by the two-hit theory.
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http://dx.doi.org/10.3389/fneur.2018.01099DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6300466PMC
December 2018

Effect of crocetin on quality of sleep: A randomized, double-blind, placebo-controlled, crossover study.

Complement Ther Med 2018 Dec 8;41:47-51. Epub 2018 Sep 8.

Oriental Ueno Detection Center, General Incorporated Association Oriental Occupational Health Association Tokyo Branch, 1-20-11 Ueno, Taito-ku, Tokyo, 110-0005, Japan.

Objectives: The aim of the present study was to investigate the effect of crocetin on sleep architecture and subjective sleep parameters in healthy adult participants with mild sleep complaints.

Design: A randomized, double-blind, placebo-controlled, crossover study with two intervention periods of 14 days each, separated by a 14-day wash-out period.

Interventions: Thirty participants were randomly assigned to one of two sequence groups. Each group was given crocetin at 7.5 mg/day, or placebo. We measured objective sleep parameters using single-channel electroencephalography and assessed subjective sleep parameters using the Oguri-Shirakawa-Azumi Sleep Inventory, Middle-age and Aged version (OSA-MA).

Main Outcome Measures: Differences between crocetin and placebo in an objective sleep parameter (delta power), and OSA-MA scores.

Results: Delta power was significantly increased with crocetin compared with placebo. There were no significant differences in the other sleep parameters, including sleep latency, sleep efficiency, total sleep time, and wake after sleep onset. Subjective scores for sleepiness on rising and feeling refreshed were significantly improved with crocetin compared with placebo.

Conclusions: The findings of the present study suggest that crocetin supplementation contributes to sleep maintenance, leading to improved subjective sleep quality.
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http://dx.doi.org/10.1016/j.ctim.2018.09.003DOI Listing
December 2018

Classification of needle-EMG resting potentials by machine learning.

Muscle Nerve 2019 02 18;59(2):224-228. Epub 2018 Dec 18.

Department of Neurology, 3-18-15 Kuramotocho, Tokushima City, 770-8503, Japan.

Introduction: The diagnostic importance of audio signal characteristics in needle electromyography (EMG) is well established. Given the recent advent of audio-sound identification by artificial intelligence, we hypothesized that the extraction of characteristic resting EMG signals and application of machine learning algorithms could help classify various EMG discharges.

Methods: Data files of 6 classes of resting EMG signals were divided into 2-s segments. Extraction of characteristic features (384 and 4,367 features each) was used to classify the 6 types of discharges using machine learning algorithms.

Results: Across 841 audio files, the best overall accuracy of 90.4% was observed for the smaller feature set. Among the feature classes, mel-frequency cepstral coefficients (MFCC)-related features were useful in correct classification.

Conclusions: We showed that needle EMG resting signals were satisfactorily classifiable by the combination of feature extraction and machine learning, and this can be applied to clinical settings. Muscle Nerve 59:224-228, 2019.
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http://dx.doi.org/10.1002/mus.26363DOI Listing
February 2019

Age-dependent texture features in skeletal muscle ultrasonography.

J Med Invest 2018 ;65(3.4):274-279

Department of Neurology, Tokushima University.

Texture analysis characterizes regions in an image by their texture content and has been utilized to infer the underlying structures of medical images such as skeletal muscles. Although potentially useful in tissue diagnosis and assessing disease progression of neuromuscular diseases, the use of texture analysis in such purposes are limited, due to lack of information such as effects of aging. Thus, we performed texture analysis of medial gastrocnemius in healthy individuals form their 20s to late 80s. Among the 283 texture features in 6 classes, the features related to histogram, co-occurrence matrix, absolute gradient, and wavelet were correlated to age in 17-40% of the parameters, while none of the features related to run-length matrix and autoregressive model had significant correlation to age. This study showed that age-dependency in many texture features are present and need to be taken into account in elucidating the clinical significance. By contrast, the features related to run-length matrix and autoregressive model could have clinical utility. J. Med. Invest. 65:274-279, August, 2018.
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http://dx.doi.org/10.2152/jmi.65.274DOI Listing
January 2019

Diacylglycerol Enhances the Effects of Alpha-Linolenic Acid Against Visceral Fat: A Double-Blind Randomized Controlled Trial.

Obesity (Silver Spring) 2017 10 29;25(10):1667-1675. Epub 2017 Aug 29.

Healthcare Food Research Laboratories, Kao Corporation, Tokyo, Japan.

Objective: To investigate the effect of alpha-linolenic acid-rich diacylglycerol (ALA-DAG) compared with alpha-linolenic acid-rich triacylglycerol (ALA-TAG) on visceral fat area (VFA) in people with overweight.

Methods: Subjects with overweight were recruited to a randomized, double-blind, controlled, parallel-group designed trial and randomly allocated to two groups that consumed either 2.5 g/d ALA-TAG or ALA-DAG for 12 weeks. Two 4-week nontreatment periods were placed before and after the treatment period. One hundred fourteen subjects (n = 57 in the ALA-TAG group, n = 57 in the ALA-DAG group) were enrolled into the analysis set for efficacy evaluation.

Results: The VFA and BMI were significantly decreased by the ALA-DAG treatment with a treatment-by-time interaction compared with the ALA-TAG treatment (P < 0.05). Additionally, the change from baseline of the fasting serum TAG concentration at week 12 was significantly decreased by ALA-DAG treatment compared with ALA-TAG treatment (P < 0.05). Safety parameters such as urinary measurements, hematologic parameters and blood biochemistry, and the incidence of adverse events did not differ significantly between groups, and no ALA-DAG-associated adverse effects were detected.

Conclusions: Incorporation of ALA-DAG in a regular diet for 12 weeks may lead to a reduction in VFA, BMI, and serum TAG in men and women with overweight.
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http://dx.doi.org/10.1002/oby.21938DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638073PMC
October 2017

Neurogenic and Myogenic Diseases: Quantitative Texture Analysis of Muscle US Data for Differentiation.

Radiology 2017 05 2;283(2):492-498. Epub 2017 Feb 2.

From the Faculty of Medicine (K.S.) and Department of Neurology (H.N., N.T., A.M., H.Y., Y.S., Y.I., R.K.), Tokushima University, 3-18-15 Kuramotocho, Tokushima 770-8503, Japan; and Department of Neurology, Vihara Hananosato Hospital, Hiroshima, Japan (N.T., Y.I.).

Purpose To assess the multiple texture features of skeletal muscles in neurogenic and myogenic diseases by using ultrasonography (US). Materials and Methods After institutional review board approval, muscle US studies of the medial head of the gastrocnemius were performed prospectively in patients with neurogenic diseases (n = 25 [18 men]; mean age, 66.0 years ± 12.3 [standard deviation]), in patients with myogenic diseases (n = 21 [12 men]; mean age, 68.3 years ± 11.5), and in healthy control subjects (n = 21 [11 men]; mean age, 70.5 years ± 8.4) between January 2013 and May 2016. Written informed consent was obtained. Muscle texture parameters were obtained, and five algorithms were used to classify the groups. Results The neurogenic and myogenic disease groups showed higher echo intensities than the control subjects. The histogram-derived texture parameters had overlaps between the neurogenic and myogenic groups and thus had a low discrimination rate. With assessment of more classes of texture parameters, three groups were correctly classified (100% correct, according to four of five classification algorithms). Tenfold cross validation showed 93.5%-95.7% correct classification between the neurogenic and myogenic groups. The run-length matrix, autoregressive model, and co-occurrence matrix were particularly useful in distinguishing the neurogenic and myogenic groups. Conclusion Texture analysis of muscle US data can enable differentiation between neurogenic and myogenic diseases and is useful in noninvasively assessing underlying disease mechanisms. RSNA, 2017 Online supplemental material is available for this article.
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http://dx.doi.org/10.1148/radiol.2016160826DOI Listing
May 2017

Sonographic evaluation of peripheral nerves in subtypes of Guillain-Barré syndrome.

J Neurol Sci 2016 May 26;364:154-9. Epub 2016 Mar 26.

Department of Neurology, Tokushima University, Tokushima, Japan.

Background: Sonography of peripheral nerves can depict alteration of nerve sizes that could reflect inflammation and edema in inflammatory and demyelinating neuropathies. Guillain-Barré syndrome (GBS). Information on sonographic comparison of an axonal subtype (acute motor [and sensory] axonal neuropathy [AMAN and AMSAN]) and a demyelinating subtype (acute inflammatory demyelinating polyneuropathy [AIDP]) has been sparse.

Material And Methods: Sonography of peripheral nerves and cervical nerve roots were prospectively recorded in patients with GBS who were within three weeks of disease onset.

Results: Five patients with AIDP and nine with AMAN (n=6)/AMSAN (n=3) were enrolled. The patients with AIDP showed evidence of greater degrees of demyelination (e.g., slower conduction velocities and increased distal latencies) than those with AMAN/AMSAN. The patients with AIDP tended to show enlarged nerves in the proximal segments and in the cervical roots, whereas the patients with AMAN/AMSAN had greater enlargement in the distal neve segment, especially in the median nerve (P = 0.03; Wrist-axilla cross-sectional ratio).

Conclusion: In this small study, two subtypes of GBS showed different patterns of involvement that might reflect different pathomechanisms.
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http://dx.doi.org/10.1016/j.jns.2016.03.042DOI Listing
May 2016

Sonographic evaluation of cervical nerve roots in ALS and its clinical subtypes.

J Med Invest 2016 ;63(1-2):54-7

Department of Neurology, Tokushima University.

Morphological assessment of peripheral nerves in amyotrophic lateral sclerosis (ALS) has been available by sonography. Detection of possible axonal atrophy could be important in predicting progression. Research on correlation between sonographic findings and clinical presentation has been sparse. The aim of the study was to assess possible motor axon loss in patients with ALS by sonography and to correlate the imaging features with clinical subtypes. Patients with either definite or probable ALS and control subjects had sonographic evaluation of the cervical nerve roots (C5, C6, and C7). Each diameter and their sums were measured. The ALS patients were classified by their clinical onset and progression (arm-onset, leg-onset, bulbar, and flail-arm variant) and the sonographic features were compared. Overall, the cervical nerve roots were thinner in ALS than in the controls, but the diagnostic sensitivity was low. The patients with arm dysfunctions tended to show thinner nerve roots than those with normal or relatively preserved arm functions. The four ALS subtypes showed similar diameters of the nerve roots. There was no correlation between the disease duration and the diameters of the nerve roots. Sonography of the cervical nerve roots showed axonal atrophy in ALS and potentially reflects subtle arm dysfunctions.
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http://dx.doi.org/10.2152/jmi.63.54DOI Listing
January 2017

Which muscle shows fasciculations by ultrasound in patients with ALS?

J Med Invest 2016 ;63(1-2):49-53

Department of Neurology, Tokushima University.

The purpose of the present study was to elucidate the relative frequencies of fasciculations assessed by sonography in a large number of muscles in patients with amyotrophic lateral sclerosis (ALS). The patients diagnosed as having ALS were retrospectively assessed by muscle sonography. The frequencies of having fasciculations were compared among the 15 muscles and the subtypes according to the initially affected body region. Overall, approximately half of the muscles had fasciculations (48.8%), in the average of 11.4 muscles per patient. The frequency of fasciculations tended to be lower in the patients with longer disease durations upon testing. Biceps brachii had the highest frequency, followed by extensor digitorum communis, whereas sternocleidomastoid and rectus abdominis had the lowest frequencies. The frequencies of fasciculations were similar among the clinical subtypes. In conclusion, in patients with ALS, fasciculations were detected most frequently in proximal arm muscles by sonography, whereas truncal muscles had lower frequencies. Fasciculations tended to be less evident in the advanced disease stage, possibly reflecting muscle degeneration. Appropriate selection of muscles to observe fasciculations is important for diagnosis of ALS.
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http://dx.doi.org/10.2152/jmi.63.49DOI Listing
January 2017

Impaired Axonal Na(+) Current by Hindlimb Unloading: Implication for Disuse Neuromuscular Atrophy.

Front Physiol 2016 16;7:36. Epub 2016 Feb 16.

Department of Neurology, Tokushima University Tokushima, Japan.

This study aimed to characterize the excitability changes in peripheral motor axons caused by hindlimb unloading (HLU), which is a model of disuse neuromuscular atrophy. HLU was performed in normal 8-week-old male mice by fixing the proximal tail by a clip connected to the top of the animal's cage for 3 weeks. Axonal excitability studies were performed by stimulating the sciatic nerve at the ankle and recording the compound muscle action potential (CMAP) from the foot. The amplitudes of the motor responses of the unloading group were 51% of the control amplitudes [2.2 ± 1.3 mV (HLU) vs. 4.3 ± 1.2 mV (Control), P = 0.03]. Multiple axonal excitability analysis showed that the unloading group had a smaller strength-duration time constant (SDTC) and late subexcitability (recovery cycle) than the controls [0.075 ± 0.01 (HLU) vs. 0.12 ± 0.01 (Control), P < 0.01; 5.4 ± 1.0 (HLU) vs. 10.0 ± 1.3 % (Control), P = 0.01, respectively]. Three weeks after releasing from HLU, the SDTC became comparable to the control range. Using a modeling study, the observed differences in the waveforms could be explained by reduced persistent Na(+) currents along with parameters related to current leakage. Quantification of RNA of a SCA1A gene coding a voltage-gated Na(+) channel tended to be decreased in the sciatic nerve in HLU. The present study suggested that axonal ion currents are altered in vivo by HLU. It is still undetermined whether the dysfunctional axonal ion currents have any pathogenicity on neuromuscular atrophy or are the results of neural plasticity by atrophy.
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http://dx.doi.org/10.3389/fphys.2016.00036DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4754663PMC
February 2016

Late-onset spastic paraplegia: Aberrant SPG11 transcripts generated by a novel splice site donor mutation.

J Neurol Sci 2015 Dec 30;359(1-2):250-5. Epub 2015 Oct 30.

Department of Clinical Neuroscience, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503, Japan. Electronic address:

We identified a novel homozygous mutation in the splice site donor (SSD) of intron 30 (c.5866+1G>A) in consanguineous Japanese SPG11 siblings showing late-onset spastic paraplegia using the whole-exome sequencing. Phenotypic variability was observed, including age-at-onset, dysarthria and pes cavus. Coding DNA sequencing revealed that the mutation affected the recognition of the constitutive SSD of intron 30, splicing upstream onto a nearby cryptic SSD in exon 30. The use of constitutive splice sites of intron 29 was confirmed by sequencing. The mutant transcripts are mostly subject to degradation by the nonsense-mediated mRNA decay system. SPG11 transcripts, escaping from the nonsense-mediated mRNA decay pathway, would generate a truncated protein (p.Tyr1900Phefs5X) containing the first 1899 amino acids and followed by 4 aberrant amino acids. This study showed a successful clinical application of whole-exome sequencing in spastic paraplegia and demonstrated a further evidence of allelic heterogeneity in SPG11. The confirmation of aberrant transcript by splice site mutation is a prerequisite for a more precise molecular diagnosis.
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http://dx.doi.org/10.1016/j.jns.2015.10.045DOI Listing
December 2015

Age-dependent effects on sensory axonal excitability in normal mice.

Neurosci Lett 2016 Jan 25;611:81-7. Epub 2015 Nov 25.

Department of Neurology, Tokushima University, Tokushima, Japan.

Serial recordings were performed to measure sensory excitability in peripheral nerves and elucidate age-dependent changes in neuronal ion currents in the peripheral sensory nervous system. The threshold tracking technique was used to measure multiple excitability indices in the tail sensory nerves of five normal male mice at four time points (6, 10, 14, and 19 weeks of age). A separate group of four mice was also measured at 43 weeks and at 60 weeks of age. Maturation was accompanied by an increase in early hyperpolarization and superexcitability at 10 weeks. At 60 weeks, the hyperpolarizing electrotonus shifted downward, while superexcitability became greater and subexcitability (double stimuli) decreased. Computer modeling showed that the most notable age-related interval changes in excitability parameters were Barrett-Barrett, H, and slow K(+) conductances. Understanding age-related changes in the excitability of sensory axons may provide a platform for understanding age-dependent sensory symptoms and developing age-specific channel-targeting therapies.
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http://dx.doi.org/10.1016/j.neulet.2015.11.032DOI Listing
January 2016

Varicella-zoster virus-specific cell-mediated immunity in Ramsay Hunt syndrome.

Laryngoscope 2016 Jan 15;126(1):E35-9. Epub 2015 Jul 15.

Division of Clinical Virology, Department of Microbiology and Infectious Disease, Kobe University Graduate School of Medicine, Kobe, Japan.

Objectives/hypothesis: The etiology of Ramsay Hunt syndrome (Hunt syndrome) is reactivation of latent varicella-zoster virus (VZV) in the geniculate ganglion of the facial nerve, leading to neuritis. Although the mechanism of the VZV reactivation is unclear, one possibility is that the reactivation involves a low level of VZV-specific cell-mediated immunity (CMI). The aim of this study was to clarify the characteristics of the VZV-specific CMI in Hunt syndrome compared to that in Bell's palsy, and to obtain clues to its role in the development of Hunt syndrome.

Study Design: Prospective study.

Methods: We determined the median spot numbers and examined VZV-specific CMI in patients with Hunt syndrome and with Bell's palsy using interferon-γ enzyme-linked immunospot (ELISPOT) assays. We analyzed the relationship between the value of VZV-specific CMI and days from disease onset.

Results: The median spot number in Hunt syndrome (87.3 spot-forming cells [SFCs]/4 × 10(5) peripheral blood mononuclear cells [PBMCs]) was higher than that in Bell's palsy (62.3 SFCs/4 × 10(5) PBMCs). Hunt syndrome showed a strong relationship between the ELISPOT count and days from onset (r = 0.65). Within the first 5 days from onset, no ELISPOT counts higher than 80 SFCs/4 × 10(5) PBMCs were observed. On the other hand, no correlation was observed between the ELISPOT count and days from onset in patients with Bell's palsy (r = -0.19).

Conclusions: These results suggest that VZV-specific CMI in Hunt syndrome is low at disease onset and increases rapidly thereafter. Consequently, reduced VZV-specific CMI may play an important role in the reactivation of VZV in the facial nerve, leading to Hunt syndrome.
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http://dx.doi.org/10.1002/lary.25441DOI Listing
January 2016

Effects of anesthetic agents on in vivo axonal HCN current in normal mice.

Clin Neurophysiol 2015 Oct 19;126(10):2033-9. Epub 2015 Jan 19.

Department of Neurology, Tokushima University, Tokushima, Japan.

Objective: The objective was to study the in vivo effects of anesthetic agents on peripheral nerve excitability.

Methods: Normal male mice were anesthetized by either isoflurane inhalation or a combination of medetomidine, midazolam, and butorphanol intraperitoneal injection ("triple agents"). Immediately after induction, the tail sensory nerve action potential was recorded and its excitability was monitored.

Results: Under both anesthetic protocols, there was an interval excitability change by long hyperpolarizing currents. There was greater threshold reduction approximately 30min post induction, in comparison to immediately post induction. Other excitability parameters were stable over time. Modeling suggested interval suppression of internodal H conductance or leak current.

Conclusions: Anesthetic agents affected responses to long hyperpolarizing currents.

Significance: Axonal excitability during intraoperative monitoring may be affected by anesthetic agents. Interpretation of interval excitability changes under anesthesia requires caution, especially with long hyperpolarizing currents.
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http://dx.doi.org/10.1016/j.clinph.2014.12.025DOI Listing
October 2015

Focal nerve enlargement is not the cause for increased distal motor latency in ALS: Sonographic evaluation.

Clin Neurophysiol 2015 Aug 1;126(8):1632-7. Epub 2014 Nov 1.

Department of Neurology, Tokushima University, Tokushima, Japan.

Objective: To elucidate the mechanism of focal conduction slowing in the median nerve in ALS.

Methods: The patients with ALS and CTS and normal control subjects were tested with sonography of the median and ulnar nerves. The cross-sectional areas (CSAs) and the wrist-forearm CSA ratios were compared with the parameters of nerve conduction study.

Results: The median motor distal latency was frequently prolonged in ALS and CTS. CSA and the wrist-forearm ratio of the median nerve were smaller in ALS than in CTS. The ulnar nerve sonography was similar in all the groups.

Conclusions: Selective conduction slowing of the median nerve at the wrist in ALS is unlikely due to secondary compressive neuropathy, as seen in carpal tunnel syndrome.

Significance: Unique vulnerability of the median nerve in ALS may explain the selective conduction slowing.
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http://dx.doi.org/10.1016/j.clinph.2014.10.152DOI Listing
August 2015

Ultrasonographic evaluation of myokymic discharges.

Clin Neurophysiol 2015 Aug 6;126(8):1638-9. Epub 2014 Nov 6.

Department of Clinical Neuroscience, Institute of Health Biosciences, Tokushima University, Tokushima, Japan.

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http://dx.doi.org/10.1016/j.clinph.2014.10.154DOI Listing
August 2015

Thinning of cervical nerve roots and peripheral nerves in ALS as measured by sonography.

Clin Neurophysiol 2014 Sep 24;125(9):1906-11. Epub 2014 Feb 24.

Department of Neurology, Tokushima University, Tokushima, Japan.

Objective: Progressive atrophy and loss of motor axons is a hallmark of amyotrophic lateral sclerosis (ALS). Limited sonographic data are available on potential detection of atrophy of peripheral nerves and nerve roots in ALS.

Methods: Patients with either definite or probable ALS and control subjects underwent sonographic evaluation of the cervical roots (C5, C6, and C7) and peripheral nerves (median and ulnar nerves) on the right. These diameters and cross-sectional areas (C6, median, and ulnar nerves) were compared.

Results: The diameters and cross-sectional areas were consistently smaller in ALS than in controls. No correlation was present between the sonographic parameters and the disease severity, disease duration, age, or gender. The overall sensitivity and specificity tended to be greater in the cervical nerve roots than in the peripheral nerves.

Conclusions: This study shows atrophy of cervical nerve roots and peripheral nerves in ALS detected by sonography. Cervical nerve roots might be more appropriate to detect motor axon loss than peripheral nerves.

Significance: Sonographic evaluation of nerve roots and peripheral nerves may be a useful disease marker in ALS to confirm the diagnosis and to potentially monitor the disease progression.
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http://dx.doi.org/10.1016/j.clinph.2014.01.033DOI Listing
September 2014

[Sonographic evaluation of myopathy].

Brain Nerve 2014 Mar;66(3):247-57

Department of Neurology, Tokushima University Hospital.

The imaging of muscle fibers has been utilized in the management of patients with suspected myopathy. Ultrasonography (US) of skeletal muscles has advantages over MRI and CT in that US can quickly assess muscles in the entire body. US findings in myopathy are diffuse (e.g., increased or decreased echo signal in muscular dystrophy and myositis) and focal (e.g., a mass in sarcoid myopathy, or preferential involvement in inclusion body myositis). US evaluation is useful in determining the potential site for a muscle biopsy, where an adequate degree of myopathy should be present. Further studies will reveal the correlation between the sonographic findings as well as clinical and other imaging abnormalities.
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March 2014

The midline electroneurography method for facial palsy reflects total nerve degeneration.

Acta Otolaryngol 2013 Mar 20;133(3):327-33. Epub 2012 Nov 20.

Department of Laboratory Medicine, Osaka Medical College, Takatsuki, Osaka, Japan.

Conclusion: The midline electroneurography (ENoG) method might reflect total facial nerve degeneration.

Objective: We compared ENoG values in patients with facial palsy using two different methods, the midline method and five electroneurogram recordings, to reveal whether the ENoG value obtained with the midline method reflects total facial nerve degeneration.

Methods: Forty patients with facial palsy were enrolled. Compound muscle action potentials (CMAPs) were recorded using the midline method, in which the anode was placed on the mental protuberance and the cathode was placed on the philtrum. Additionally, five electroneurogram recordings were obtained by placing the anode on the skin of the parietal region and five cathodes on the skin over five facial muscles (frontalis, orbicularis oculi, nasalis, orbicularis oris, and depressor anguli oris muscles). ENoG values recorded using the two methods were compared.

Results: The ENoG values of the five facial muscles did not differ from those obtained using the midline method. The total ENoG value calculated by summing five CMAPs from five facial muscles, which is considered to reflect total facial nerve degeneration, was not significantly different from that using midline methods; moreover, a strong positive correlation coefficient (r = 0.87) was found between them.
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http://dx.doi.org/10.3109/00016489.2012.743680DOI Listing
March 2013

Metastatic breast carcinoma to bilateral internal auditory canals.

Otol Neurotol 2012 Jul;33(5):e35-6

Department of Otolaryngology, Osaka Medical College, Takatsuki, Japan.

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http://dx.doi.org/10.1097/MAO.0b013e318241b6fcDOI Listing
July 2012

Peripheral nerve excitability measures at different target levels: the effects of aging and diabetic neuropathy.

J Clin Neurophysiol 2010 Oct;27(5):350-7

Department of Neurology, Tokushima University, Tokushima, Japan.

Threshold tracking testing has provided novel insights of peripheral nerve excitability in normal and pathologic conditions. However, little has been known on the nerve excitability properties of axons with different stimulation thresholds and the effects of aging and peripheral neuropathy to those. We performed multiple nerve excitability tests in normal controls divided into three age groups and in patients with diabetic neuropathy, which were recorded at three target levels (10%, 40%, and 60% of the maximum motor response amplitudes). In all the control groups, tracking at low target level shows smaller threshold change by hyperpolarizing stimuli and greater threshold change by depolarizing stimuli, suggestive of greater transient Na current. Normal elderly showed greater threshold change by hyperpolarizing pulse than younger subjects at high target level, likely reflecting decrease of axon diameters. Patients with diabetic neuropathy showed smaller threshold changes by both depolarizing and hyperpolarizing pulses ("fanning-in"), more noticeably at the lower target level, suggestive of the combined effects of membrane depolarization and greater decrease of axonal diameters in smaller fibers. Given the reported unpredictable electrical recruitment order in the diseased conditions and difference of nerve excitability measures in threshold electrotonus at different target levels, comparing threshold electrotonus values between normal and diseased axons may be problematic by comparing axons with different nerve excitability characteristics.
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http://dx.doi.org/10.1097/WNP.0b013e3181f387abDOI Listing
October 2010

Transverse myelitis and polymyositis associated with antiphospholipid antibody syndrome.

Clin Neurol Neurosurg 2010 Oct 20;112(8):713-6. Epub 2010 May 20.

Department of Neurology, Tokushima University, Tokushima, Japan.

Antiphospholipid antibody syndrome (APS) has been widely recognized to be associated with various neurological complications. In addition to the classical notion of APS as a thrombotic disorder, APS has been suggested to be an autoinflammatory disease as well. We present a previously healthy 46-year-old man who concurrently developed transverse myelitis and polymyositis whose laboratory studies were significant for the elevated antiphospholipid antibodies such as anti-cardiolipin (CL)/beta2-glycoprotein I (beta 2GPI) antibody. This report further enhances the recognized clinical phenotypes of the neurological complications of APS and the understanding of its pathomechanism.
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http://dx.doi.org/10.1016/j.clineuro.2010.04.017DOI Listing
October 2010

Threshold-dependent effects on peripheral nerve in vivo excitability properties in the rat.

Neurosci Lett 2010 Jan 10;468(3):248-53. Epub 2009 Nov 10.

Department of Neurology, Tokushima University, Tokushima, Japan.

Various factors, including maturity, have been shown to influence peripheral nerve excitability measures, but little is known about differences in these properties between axons with different stimulation thresholds. Multiple nerve excitability tests were performed on the caudal motor axons of immature and mature female rats, recording from tail muscles at three target compound muscle action potential (CMAP) levels: 10%, 40% ("standard" level), and 60% of the maximum CMAP amplitude. Compared to lower target levels, axons at high target levels have the following characteristics: lower strength-duration time constant, less threshold reduction during depolarizing currents and greater threshold increase to hyperpolarizing currents, most notably to long hyperpolarizing currents in mature rats. Threshold-dependent effects on peripheral nerve excitability properties depend on the maturation stage, especially inward rectification (Ih), which becomes inversely related to threshold level. Performing nerve excitability tests at different target levels is useful in understanding the variation in membrane properties between different axons within a nerve. Because of the threshold effects on nerve excitability and the possibility of increased variability between axons and altered electric recruitment order in disease conditions, excitability parameters measured only at the "standard" target level should be interpreted with caution, especially the responses to hyperpolarizing currents.
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http://dx.doi.org/10.1016/j.neulet.2009.11.006DOI Listing
January 2010
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