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Dive into the research topics where Isabelle Miyazawa is active.

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Featured researches published by Isabelle Miyazawa.


Journal of Neurology, Neurosurgery, and Psychiatry | 2006

Clinical and MRI features of Japanese patients with multiple sclerosis positive for NMO-IgG

Ichiro Nakashima; Kazuo Fujihara; Isabelle Miyazawa; Tatsuro Misu; Koichi Narikawa; Masashi Nakamura; Shohei Watanabe; Toshiyuki Takahashi; Shuhei Nishiyama; Yusei Shiga; Shigeru Sato; Brian G. Weinshenker; Yasuto Itoyama

This study investigates the relation between the serological status of NMO (neuromyelitis optica)-IgG and the clinical and MRI features in Japanese patients with multiple sclerosis. Serum NMO-IgG was tested in 35 Japanese patients diagnosed with multiple sclerosis, including 19 with the optic–spinal form of multiple sclerosis (OSMS), three with the spinal form of multiple sclerosis (SMS), and 13 with the conventional form of multiple sclerosis (CMS), which affects the brain. NMO-IgG was detected in 14 patients, 12 with OSMS and 2 with CMS. In these patients, longitudinally extensive (>3 vertebral segments) spinal cord lesions (93% v 57%) and permanent, complete blindness (no perception of light) in at least one eye (50% v 0%) were the noticeable features as compared with NMO-IgG-negative OSMS. The two patients having CMS with NMO-IgG had unusual brain lesions, but in other respects had features suggesting OSMS. NMO-IgG was detected in more than half the number of patients with OSMS and in some patients with CMS. This newly discovered serum autoantibody was markedly associated with longitudinally extensive spinal cord lesions and with complete blindness, suggesting severe optic–spinal disease.


Multiple Sclerosis Journal | 2007

Therapeutic efficacy of plasma exchange in NMO-IgG-positive patients with neuromyelitis optica.

Shohei Watanabe; Ichiro Nakashima; Teruhisa Misu; Isabelle Miyazawa; Yusei Shiga; Kazuo Fujihara; Yasuto Itoyama

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system (CNS) with a poor prognosis in terms of the optic-spinal function. Recently, a serum autoantibody (NMO-IgG) binding to the blood–brain barrier region was detected exclusively in patients with NMO and its high risk group. We treated six NMO-IgG-positive patients (all female; age 21–67 years old, median 41; three with optic neuritis and three with myelitis) who were unresponsive to high-dose intravenous methylprednisolone (HIMP), with plasma exchange (PE) (three to five exchanges, 2–3 L each). Three of the patients(one with optic neuritis and two with myelitis) showed definite functional improvement following PE. The clinical improvement started to appear after one or two exchanges, while there was little or no improvement in the other three patients. Such quick clinical responses to PE suggest a pathogenetic role of humoral immune factors in NMO, although delayed responses to the corticosteroid therapy might have contributed to the therapeutic efficacy, in part. Further clinical and in vitro studies are needed to determine whether the removal of NMO-IgG is directly relevant to the therapeutic efficacy. PE may hasten the functional recovery from corticosteroid-resistant relapses in some NMO-IgG-positive patients with NMO.


Journal of Neurology, Neurosurgery, and Psychiatry | 2008

Intractable hiccup and nausea in neuromyelitis optica with anti-aquaporin-4 antibody: a herald of acute exacerbations

Toshiyuki Takahashi; Isabelle Miyazawa; Tatsuro Misu; Rina Takano; Ichiro Nakashima; Kazuo Fujihara; Muneshige Tobita; Yasuto Itoyama

Background: Intractable hiccup and nausea (IHN) are unique symptoms in neuromyelitis optica (NMO). Recent studies have strongly suggested that the pathogenesis of NMO is closely associated with anti-aquaporin-4 (AQP4) antibody. However, clinical implications of IHN and the relationship with anti-AQP4 antibody remain unknown. Methods: The past medical records of 35 patients with seropositivity for anti-AQP4 antibody were reviewed. We also followed the titres of anti-AQP4 antibody in a patient with NMO, who had newly developed IHN. Results: Of the 35 patients, 15 patients (43%) had episodes of IHN. There was a total of 35 episodes of IHN in these 15 patients and, of the 35 episodes, hiccup was seen in 23 episodes (66%) and nausea was seen in 28 episodes (80%). The IHN frequently preceded (54%) or accompanied (29%) myelitis or optic neuritis. The IHN was often preceded by an episode of viral infection. The titres of anti-AQP4 antibody were remarkably increased when the intractable hiccup appeared in a case. Conclusions: IHN could be a clinical marker for the early phase of an exacerbation. Careful observation may be needed when INH is seen in patients with NMO, and the early initiation of the treatment could prevent subsequent neurological damage.


Journal of Neurology | 2008

Preferential spinal central gray matter involvement in neuromyelitis optica : An MRI study

Masashi Nakamura; Isabelle Miyazawa; Kazuo Fujihara; Ichiro Nakashima; Tatsuro Misu; Shohei Watanabe; Toshiyuki Takahashi; Yasuto Itoyama

To delineate the MRI features that distinguish neuromyelitis optica (NMO) from multiple sclerosis (MS). We compared the distribution of the spinal cord lesions by analyzing 1) lesion area, 2) lesion density (by superimposing the lesions onto the standard sections of the cervical and thoracic cord with appropriate transparencies using computer software), and 3) T1-hypointensity in axial sections of MRI in NMO and MS. In NMO, 60–70% of the cervical and thoracic cord MRI lesions occupied more than half of the cord area and mainly involved the central gray matter in the acute stage. In the chronic stage, half or more of the lesions were localized at the central gray matter region. The lesion superimposition analysis also revealed much higher densities in the central gray matter region than in the peripheral white matter regions. Two patients with NMO had T1-hypointense lesions in the central region. In contrast, over 80% of the lesions in MS were localized in the lateral and posterior white matter regions of the cord in the chronic as well as acute stage. Lesion densities were much higher in the lateral and posterior white matter regions than in the central gray matter region. None of the lesions in MS were T1-hypointense. These MRI findings strongly suggest a preferential involvement in the spinal central gray matter in NMO which is distinct from MS.ObjectiveTo delineate the MRI features that distinguish neuromyelitis optica (NMO) from multiple sclerosis (MS).MethodsWe compared the distribution of the spinal cord lesions by analyzing 1) lesion area, 2) lesion density (by superimposing the lesions onto the standard sections of the cervical and thoracic cord with appropriate transparencies using computer software), and 3) T1-hypointensity in axial sections of MRI in NMO and MS.ResultsIn NMO, 60–70% of the cervical and thoracic cord MRI lesions occupied more than half of the cord area and mainly involved the central gray matter in the acute stage. In the chronic stage, half or more of the lesions were localized at the central gray matter region. The lesion superimposition analysis also revealed much higher densities in the central gray matter region than in the peripheral white matter regions. Two patients with NMO had T1-hypointense lesions in the central region. In contrast, over 80% of the lesions in MS were localized in the lateral and posterior white matter regions of the cord in the chronic as well as acute stage. Lesion densities were much higher in the lateral and posterior white matter regions than in the central gray matter region. None of the lesions in MS were T1-hypointense.ConclusionsThese MRI findings strongly suggest a preferential involvement in the spinal central gray matter in NMO which is distinct from MS.


Multiple Sclerosis Journal | 2009

Occurrence of acute large and edematous callosal lesions in neuromyelitis optica

Masahiko Nakamura; Tatsuro Misu; Kazuo Fujihara; Isabelle Miyazawa; Ichiro Nakashima; Toshiyuki Takahashi; Shohei Watanabe; Yasuto Itoyama

Background The corpus callosum is commonly involved in multiple sclerosis (MS), but the characteristics of callosal lesions in neuromyelitis optica (NMO) are unknown. Objective To reveal the features of callosal lesions in NMO in comparison to MS. Methods We retrospectively reviewed the medical records and the brain magnetic resonance imaging films of 56 patients with MS and 22 patients with NMO. Results In MS, 36 (64.3%) of 56 patients had callosal lesions, but only four patients had acute lesions. All such acute lesions were small, isolated and non-edematous, and the intensity was homotonic. Chronic lesions were observed in 34 patients with MS, and 32 (94%) of them presented small lesions located at the callosal lower margin (“hemi-oval pattern”). Meanwhile, four (18.2%) patients with NMO had callosal lesions, and three of them had acute lesions. Those acute lesions were multiple, large edematous ones with heterogeneous intensity (“marbled pattern”). In the chronic stage, the lesions shrank or disappeared. Conclusions Acute large, edematous callosal lesions occasionally occur in NMO. Similar to longitudinally extensive transverse myelitis, such callosal lesions may reflect severe edematous inflammation in NMO, and may provide additional evidence that the pathogenesis in NMO is different from that in MS.


Journal of Neurology | 2007

Two subtypes of optic-spinal form of multiple sclerosis in Japan : clinical and laboratory features

Ichiro Nakashima; Toshiyuki Fukazawa; Kohei Ota; Chiyoko Nohara; Yoko Warabi; Takashi Ohashi; Isabelle Miyazawa; Kazuo Fujihara; Yasuto Itoyama

Seventy-seven cases of the optic-spinal form of multiple sclerosis (OSMS) were collected from 6 institutes in 3 cities of Japan, and the clinical and MRI features were analyzed. Two-thirds of the OSMS patients had longitudinally extensive spinal cord MRI lesions (LESL), and had clinical features similar to those of relapsing neuromyelitis optica which often causes severe disability. In contrast, OSMS patients without LESL tended to have milder disease and had some feature commonly seen in the conventional form of MS. The percentage of OSMS without LESL in total OSMS has recently been increasing. The present study suggests that LESL is crucially important for distinguishing the two subtypes of OSMS.


Neurology | 2007

High CSF neurofilament heavy chain levels in neuromyelitis optica

Isabelle Miyazawa; Ichiro Nakashima; Axel Petzold; Kazuo Fujihara; Shigeru Sato; Yasuto Itoyama

The neurofilament heavy chain (NfHSMI35), a biomarker of axonal damage in the CSF, was measured in patients with neuromyelitis optica (NMO) and multiple sclerosis (MS). Significantly high CSF NfHSMI35 levels (>0.73 ng/mL) were found in 6 of 24 (25%) of the patients with NMO but none of the patients with MS (0/24). This finding suggests that axonal damage is more severe in NMO than in MS.


Journal of Neuroimmunology | 2005

CSF-chemokines in HTLV-I-associated myelopathy: CXCL10 up-regulation and therapeutic effect of interferon-α

Koichi Narikawa; Kazuo Fujihara; Tatsuro Misu; Juichi Fujimori; Ichiro Nakashima; Isabelle Miyazawa; Hiroshi Saito; Shigeru Sato; Yasuto Itoyama

We measured four chemokines in the cerebrospinal fluid (CSF) in human T-lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) with ELISA. CXCL10/IP-10, a T cell type 1 (Th1)-associated chemokine, was significantly elevated in HAM/TSP compared with controls, and the values were even significantly higher in HAM/TSP than in multiple sclerosis (MS) in which CXCL10/IP-10 up-regulation was previously reported. Among Th2-associated chemokines, CCL17/TARC and CCL11/Eotaxin in HAM/TSP were not different from those in controls. As shown in MS, CCL2/MCP-1 was significantly lower in HAM/TSP than in control. Following interferon (IFN)-alpha therapy in HAM/TSP, CCL2/MCP-1 became significantly higher than that before therapy, which may reflect a Th2 induction, while CXCL10/IP-10 remained elevated.


Multiple Sclerosis Journal | 2007

Clinical and laboratory features of neuromyelitis optica with oligoclonal IgG bands.

Masahiko Nakamura; Ichiro Nakashima; Shigeru Sato; Isabelle Miyazawa; Kazuo Fujihara; Yasuto Itoyama

Of 23 neuromyelitis optica (NMO) cases, we found two cases with oligoclonal IgG bands (OBs). Both patients were positive for NMO-IgG. Their common features were long disease duration and co-existing autoimmune diseases (myasthenia gravis and sicca syndrome). Although OBs are mostly negative in NMO, which distinguishes it from multiple sclerosis (MS), they can be positive by long-standing autoimmunity, which may not be directly related to NMO. Multiple Sclerosis 2007; 13: 332-335. http://msj.sagepub.com


Journal of Neuroimmunology | 2005

Chemokine profile in the cerebrospinal fluid and serum of Vogt–Koyanagi–Harada disease

Isabelle Miyazawa; Toshiaki Abe; Koichi Narikawa; Tatsuro Misu; Ichiro Nakashima; Juichi Fujimori; Makoto Tamai; Kazuo Fujihara; Yasuto Itoyama

We analyzed the concentrations of four chemokines in the cerebrospinal fluid (CSF) and sera in Vogt-Koyanagi-Harada disease (VKH), an autoimmune uveomeningitis syndrome against melanocyte-associated proteins, with ELISA. CSF-CXCL10/IP-10 and CSF-CCL17/TARC were significantly elevated in VKH than in controls. In the majority of VKH cases and controls, CSF-CXCL10 was higher than serum-CXCL10, and CSF-CCL17 was lower than serum-CCL17. CCL11/Eotaxin was not different between groups. CSF-CCL2/MCP-1 was significantly lower in VKH than in control. The changes in VKH were essentially similar to those in multiple sclerosis, a known Th1-dominant condition.

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Yasuto Itoyama

International University of Health and Welfare

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Tatsuro Misu

University of São Paulo

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Shigeru Sato

Jichi Medical University

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Juichi Fujimori

Tohoku Pharmaceutical University

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