S Tokiguchi

The University of Tokyo, 白山, Tōkyō, Japan

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Publications (46)150.11 Total impact

  • K. Okamoto · J. Ito · T. Furusawa · K. Sakai · K. Ono · M. Watanabe · S. Tokiguchi ·

    European Radiology 02/2014; 8(2):319-320. DOI:10.1007/s003300050388 · 4.01 Impact Factor
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    ABSTRACT: Multiple system atrophy (MSA) has been considered a sporadic disease, without patterns of inheritance. To describe the clinical features of 4 multiplex families with MSA, including clinical genetic aspects. Clinical and genetic study. Four departments of neurology in Japan. Patients Eight patients in 4 families with parkinsonism, cerebellar ataxia, and autonomic failure with age at onset ranging from 58 to 72 years. Two siblings in each family were affected with these conditions. Clinical evaluation was performed according to criteria by Gilman et al. Trinucleotide repeat expansion in the responsible genes for the spinocerebellar ataxia (SCA) series and for dentatorubral-pallidoluysian atrophy (DRPLA) was evaluated by polymerase chain reaction. Direct sequence analysis of coding regions in the alpha-synuclein gene was performed. Consanguineous marriage was observed in 1 of 4 families. Among 8 patients, 1 had definite MSA, 5 had probable MSA, and 2 had possible MSA. The most frequent phenotype was MSA with predominant parkinsonism, observed in 5 patients. Six patients showed pontine atrophy with cross sign or slitlike signal change at the posterolateral putaminal margin or both on brain magnetic resonance imaging. Possibilities of hereditary ataxias, including SCA1 (ataxin 1, ATXN1), SCA2 (ATXN2), Machado-Joseph disease/SCA3 (ATXN1), SCA6 (ATXN1), SCA7 (ATXN7), SCA12 (protein phosphatase 2, regulatory subunit B, beta isoform; PP2R2B), SCA17 (TATA box binding protein, TBP) and DRPLA (atrophin 1; ATN1), were excluded, and no mutations in the alpha-synuclein gene were found. Findings in these multiplex families suggest the presence of familial MSA with autosomal recessive inheritance and a genetic predisposition to MSA. Molecular genetic approaches focusing on familial MSA are expected to provide clues to the pathogenesis of MSA.
    JAMA Neurology 05/2007; 64(4):545-51. DOI:10.1001/archneur.64.4.545 · 7.42 Impact Factor

  • Movement Disorders 04/2007; 22(5):748-9. DOI:10.1002/mds.21365 · 5.68 Impact Factor
  • K Okamoto · T Furusawa · K Ishikawa · K Sasai · S Tokiguchi ·
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    ABSTRACT: The vestibular nucleus cannot be visualized on MR imaging, but some patients with vestibular schwannoma show a tiny area of hyperintensity in the dorsal brain stem on T2-weighted images. The aim of this study was to determine whether this tiny area is characteristic of vestibular schwannoma. We retrospectively reviewed the postoperative MR images of 53 patients with cerebellopontine angle tumor. MR images were obtained with a 1.5T scanner. Spin-echo pre- and postcontrast 3-mm-thick T1-weighted axial images, 3-mm-thick fast spin-echo (FSE) T2-weighted axial images, and 0.8-mm-thick constructive interference in steady state (CISS) axial images were acquired. Surgical and histopathologic diagnosis was vestibular schwannoma (41/53 = 77%), meningioma (7/53 = 13%), epidermoid cyst (3/53 = 6%), glioma with exophytic growth (1/53 = 2%), and chordoma (1/53 = 2%). A tiny area of hyperintensity was observed at the lateral angle of the fourth ventricle floor in 6 patients (3 men, 3 women; age range, 24-54 years; mean age, 43 years) with vestibular schwannoma larger than 2 cm in maximal diameter on both FSE T2-weighted and CISS images. Preoperative MR images with the same pulse sequences showed the same area of hyperintensity in all these patients. Because the location of the area of hyperintensity is coincident with the vestibular nucleus, the hyperintensity may represent degeneration of the nucleus. This hyperintensity should not be confused with a postoperative lesion or a small infarction. If such hyperintensity is seen in a patient with a large cerebellopontine angle tumor, a diagnosis of vestibular schwannoma is suggested.
    American Journal of Neuroradiology 12/2004; 27(6):1307-11. · 3.59 Impact Factor
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    ABSTRACT: Brain tumor is a distinct pathological entity that differs from other diseases, including cerebrovascular, demyelinating, inflammatory, infectious, and various miscellaneous diseases. Insidious onset and gradual progression of signs and symptoms are common in patients with brain tumors, whereas the onset of cerebrovascular diseases is usually acute or sudden. Patients with demyelinating, inflammatory, or infectious diseases show subacute onset. Differentiation of brain tumors from other disorders is usually possible from the clinically and radiologically characteristic features. However, in some diseases other than brain tumors, an atypical clinical course and/or radiological findings may suggest or simulate those of brain tumors. The diagnosis of brain tumor is confirmed histopathologically, and appropriate therapies are given to the patient based on the histopathological type and grade of the tumor. In order to obtain a specimen for histopathological examination, surgical intervention is required. Other diseases are usually diagnosed clinically and radiologically. Invasive procedures should be avoided in making a diagnosis. Therefore, differentiation of brain tumors from other diseases is a critical issue for neuroimaging. Detailed inspection of images is necessary, and characteristic findings, and additional imaging methods, such as diffusion-weighted imaging, are often helpful for the differential diagnosis. We assess the imaging findings of diseases simulating brain tumors and review the literature.
    Radiation Medicine 05/2004; 22(2):63-76.
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    ABSTRACT: Distribution of lesions or involvement of specific anatomic sites can suggest the diagnosis of disease. The purpose of this study was to investigate what diseases affect both middle cerebellar peduncles (MCPs) and to evaluate other MR features for differential diagnosis. MR findings of 27 patients (14 male and 13 female; age range, 4-77 years [mean, 48.5 years]) with bilateral MCP lesions were retrospectively studied. Neurodegenerative diseases were the most frequent diagnoses (n = 11 [41%]: sporadic olivopontocerebellar atrophy, eight; Shy-Drager syndrome, one; spinocerebellar ataxia, two). Also included were metabolic diseases (n = 6 [22%]: adrenoleukodystrophy, two; Wilson disease, two; cirrhosis of the liver, one; and hypoglycemia, one); cerebrovascular diseases, including posterior reversible encephalopathy syndrome (n = 3 [11%]: infarction, one; hypertensive encephalopathy, one; cyclosporin-A encephalopathy, one), demyelinating and inflammatory diseases (n = 4 [15%]: multiple sclerosis, one; acute disseminated encephalomyelitis, one; Behçet disease, one; and HIV encephalopathy, one), and neoplasms (n = 3 [11%]: lymphoma, one; glioma, one; meningeal carcinomatosis, one). All patients showed symmetrical T2 hyperintensity in both MCPs, except for one with malignant lymphoma. Marked atrophy in the posterior fossa was characteristically seen in neurodegenerative diseases. Enlargement of the pons was observed in hypertensive encephalopathy and neoplasms but absent in meningeal carcinomatosis. Lesions were restricted in the posterior fossa in eight patients with neurodegenerative diseases and one with brain stem glioma. Other patients had supratentorial lesions. Symmetricity of MCP lesions, morphologic change of the posterior fossa structures, and distribution of other lesions are helpful in the differential diagnosis.
    American Journal of Neuroradiology 11/2003; 24(10):1946-54. · 3.59 Impact Factor
  • K Okamoto · J Ito · N Takahashi · K Ishikawa · T Furusawa · S Tokiguchi · K Sakai ·
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    ABSTRACT: The clinical management and prognosis of patients with diffusely infiltrating astrocytomas are dependent on neuropathological grading of the tumors. The characteristics of MR images of high-grade astrocytic tumors are well known, but the early MRI appearance and the MRI evolution of high-grade astrocytic tumors have rarely been examined. We retrospectively reviewed MR images obtained from 4 months to 3 years and 3 months before admission, as well as MR images on admission, for five patients with pathologically proven high-grade astrocytic tumors (two glioblastomas and three anaplastic astrocytomas). In two patients, neoplastic lesions were not detectable on initial MRI, even retrospectively. In the remaining three patients, however, hyperintense areas with little or no mass effect were demonstrated on T2-weighted imaging. These lesions were misinterpreted as non-neoplastic processes, such as ischemic lesion or infarction, or demyelinating processes. All tumors showed gadolinium enhancement on admission, that emerged from the previously existing hyperintense areas on T2-weighted images without gadolinium enhancement, except for one de novo glioblastoma. Development of a small central cyst without gadolinium enhancement was demonstrated in one case before the emergence of an enhancing area.
    Neuroradiology 06/2002; 44(5):395-402. DOI:10.1007/s00234-001-0725-3 · 2.49 Impact Factor
  • K Okamoto · J Ito · K Ishikawa · K Morii · M Yamada · N Takahashi · S Tokiguchi · T Furusawa · K Sakai ·
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    ABSTRACT: Germ-cell tumors of the central nervous system generally develop in the midline, but the tumors can also occur in the basal ganglia and/or thalamus. However, MR images have rarely been documented in the early stage of the tumor in these regions. We retrospectively reviewed MR images obtained on admission and approximately 3 years earlier in two patients with germinoma in the basal ganglia, and compared them with CT. In addition to hyperdensity on CT, both hyperintensity on T1-weighted images and a small hyperintense lesion on T2-weighted images were commonly seen in the basal ganglia. These findings may be early MRI signs of germinoma in this region, and the earliest and most characteristic diagnostic feature on MRI was atrophy of the basal ganglia, which was recognizable before development of hemiparesis.
    Neuroradiology 06/2002; 44(5):389-94. DOI:10.1007/s00234-001-0735-1 · 2.49 Impact Factor
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    ABSTRACT: We report a case of frontotemporal dementia and parkinsonism linked to chromosome 17 of 5 years' duration in an 81-year-old man whose brother had died at age 86 years with dementia. In this patient, we found frontal and temporal neuronal loss, glial-predominant tau deposits, progressive supranuclear palsy-like straight tubules, accumulation of 4-repeat-predominant Sarkosyl-insoluble tau, and a novel exon 1 (Arg5His) tau gene mutation. This mutation decreased microtubule-promoting capacity and increased fibrillation of tau in vitro. Thus, we consider that the Arg5His mutation is an authentic tau gene abnormality responsible for the patient's tau pathology and late-onset dementia.
    Annals of Neurology 04/2002; 51(4):525-30. DOI:10.1002/ana.10163 · 9.98 Impact Factor
  • K Okamoto · J Ito · S Tokiguchi · K Ishikawa · T Furusawa · K Sakai ·
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    ABSTRACT: We report MRI findings in four patients with essential primary cutis verticis gyrata (CVG). The patients were all men, aged 49-81 years (mean 65 years). They had no symptoms related to this rare scalp condition, preceding scalp disease or associated systemic disease. Coronal images showed a characteristic corrugated appearance of the thickened scalp at the vertex, diagnostic of CVG. Neuroradiologists should be aware of this condition.
    Neuroradiology 11/2001; 43(10):841-4. DOI:10.1007/s002340100591 · 2.49 Impact Factor
  • K Okamoto · J Ito · K Ishikawa · K Sakai · S Tokiguchi ·
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    ABSTRACT: The amount of fat in various parts of the body decreases in emaciated patients, but responds differently to disease processes. The order of disappearance of fat in various parts of the head has rarely been studied with MRI. We imaged ten patients with anorexia nervosa and one cachectic patient with a psychiatric disorder with a 1.5 T imager. Signal intensities of bone marrow of the skull, subcutaneous tissue, and orbits were assessed on T1- and T2-weighted images, and correlated with the body mass index (BMI) and haemoglobin concentration (Hb). On T1-weighted images, five patients (BMI 15.6-17.8 kg/m2, mean 16.6 kg/m2; Hb 10.1-14.2 g/dl, mean 13.8 g/dl) showed the normal pattern of fat. One (BMI 13.6 kg/m2, Hb 10.4 g/dl) lost the high signal of bone marrow, but high signal of subcutaneous tissue and the orbits was preserved. High signal from bone marrow and subcutaneous tissue disappeared in three patients (BMI 11.5-13.5 kg/m2, mean 12.5 kg/m2; Hb 7.9-9.7 g/dl, mean 8.7 g/dl), but orbital high signal was preserved. The remaining two patients (BMI 9.3 and 13.5 kg/m2, mean 11.5 kg/m2; Hb 7.6 and 8.9 g/dl, mean 8.3 g/dl) showed complete loss of high signal from fat in the head. The order of disappearance of fat (bone marrow, subcutaneous fat, then orbits) correlated with both BMI and Hb. Atrophy of bone marrow was demonstrated on T2-weighted images in five patients with BMI 13.5 kg/m2 or less, and Hb 9.7 g/dl or less.
    Neuroradiology 03/2001; 43(2):134-8. DOI:10.1007/s002340000453 · 2.49 Impact Factor
  • K Okamoto · J Ito · K Sakai · K Ishikawa · N Takahashi · S Tokiguchi ·
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    ABSTRACT: The purpose of this work was to evaluate signal intensity change of the middle cerebellar peduncles on diffusion-weighted imaging in patients with large supratentorial lesions. Signal intensity of the middle cerebellar peduncles was measured using a region of interest in 40 normal control subjects and in 28 patients with moyamoya disease on axial diffusion-weighted imaging with the motion-probing gradient perpendicular to the image. An additional six patients without moyamoya but with large supratentorial sequelae of hemorrhage or infarction were also included. There was no difference in signal intensity between both middle cerebellar peduncles in normal subjects, but lower signal intensity was consistently observed in the contralateral middle cerebellar peduncle in 12 moyamoya patients with large supratentorial lesions in the middle cerebral artery distribution. This finding was observed in the six non-moyamoya patients, too. Decreased signal intensity of the contralateral middle cerebellar peduncle might be a remote effect caused by a large supratentorial lesion in a crossed cerebellar fashion.
    Journal of Computer Assisted Tomography 01/2001; 25(1):106-12. DOI:10.1097/00004728-200101000-00020 · 1.41 Impact Factor
  • K Okamoto · J Ito · T Saito · H Usuda · T Furusawa · K Sakai · S Tokiguchi ·
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    ABSTRACT: The "target sign" is a common finding in granulomatous infection. A case with the target sign in metastatic brain tumor from small cell lung carcinoma is reported.
    European Radiology 02/2000; 10(1):154-6. DOI:10.1007/s003300050024 · 4.01 Impact Factor
  • K Okamoto · J Ito · H Takahashi · I Emura · H Mori · T Furusawa · K Sakai · T Higuchi · S Tokiguchi ·
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    ABSTRACT: We present a case of solitary infantile myofibromatosis of the skull in a 3-month-old boy. A right parietal subcutaneous lump was found at birth, and it increased in size over the ensuing 3 months. Surgery was performed, and a diagnosis of myofibromatosis was confirmed histopathologically. Solitary myofibromatosis of the skull is extremely rare. The radiographical, CT, and MR appearances, as well as histopathological findings, are described in this article.
    European Radiology 02/2000; 10(1):170-4. DOI:10.1007/s003300050028 · 4.01 Impact Factor
  • K Okamoto · J Ito · K Ishikawa · K Sakai · S Tokiguchi ·
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    ABSTRACT: We assess diffusion-weighted MR images in the differential diagnosis of intracranial brain tumors and tumor-like conditions. Heavily diffusion-weighted (b = 1100 or 1200 s/mm2) axial images were obtained with single-shot echo-planar technique in 93 patients with pathologically confirmed various intracranial tumors and tumor-like conditions with diffusion gradient perpendicular to the images. We compared signal intensity of the lesions with those of gray and white matter, and cerebrospinal fluid (CSF). In 29 cases (31.1%) the lesions were isointense to gray and/or white matter. However, 5 cases (5.4%) showed extremely increased signal intensity: two epidermoid cysts; two chordomas; and one brain abscess. The entire portion of a tumor was markedly hyperintense in 10 cases (10.8%): four malignant lymphomas; four medulloblastomas; one germinoma; and one pineoblastoma. A CSF-like hypointense signal was seen in many cystic tumors, and cystic or necrotic portions of tumors. A neurosarcoid granulation was the only solid lesion showing characteristically a hypointense signal like CSF. The combination of markedly hyperintense and hypointense signals was seen generally in hemorrhagic tumors. Diffusion-weighted echo-planar MR imaging is useful in the differential diagnosis of brain tumors and tumor-like conditions, and suggests specific histological diagnosis in some cases.
    European Radiology 02/2000; 10(8):1342-50. DOI:10.1007/s003309900310 · 4.01 Impact Factor
  • K Okamoto · J Ito · T Furusawa · K Sakai · S Tokiguchi ·
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    ABSTRACT: We reviewed the imaging of four pathologically proven calvarial eosinophil granulomas. The diameter of the lesions ranged from 13 to 40 mm; three were biconvex, but the other had a collar-stud appearance. Two lesions were in the frontal and two in the parietal bone. On bone-window CT, a bevelled edge was seen in three cases and button sequestration in one, but no sclerotic rim was shown. Although one lesion had a low-density area, the lesions were slightly denser than grey matter. They were isointense with grey or white matter on T1-weighted MRI and gave heterogeneous high signal on proton-density and T2-weighted images. All enhanced markedly, with a less strongly enhancing portion within them. A tail of dural enhancement and reactive change in the overlying galea or temporal muscle were seen in all cases.
    Neuroradiology 11/1999; 41(10):723-8. DOI:10.1007/s002340050831 · 2.49 Impact Factor
  • Masami Tanaka · Keiko Tanaka · Susumu Tokiguchi · Kazuki Shinozawa · Shoji Tsuji ·
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    ABSTRACT: Anti-Yo antibodies are present in the sera and cerebrospinal fluid of some patients with paraneoplastic cerebellar degeneration (PCD), but there is no evidence that the presence of anti-Yo antibodies causes the Purkinje cell loss seen in PCD patients. We examined the level of cytotoxic T lymphocyte (CTL) activity against a nine-amino acid peptide of the Yo protein using the Human Leukocyte Antigen- (HLA-) based approach called reverse immunogenetics. Mononuclear cells (MNCs) were isolated from the peripheral venous blood and fibroblasts were obtained from the skin of three patients with PCD with anti-Yo antibody. After activating the MNCs of the three patients with the peptide, it showed CTL activity against the Yo protein peptide expressed on autologous fibroblasts. Therefore, CTLs may be involved in the loss of Purkinje cells in PCD.
    Journal of the Neurological Sciences 10/1999; 168(1):28-31. DOI:10.1016/S0022-510X(99)00163-X · 2.47 Impact Factor
  • K Okamoto · J Ito · R Ogawa · T Furusawa · K Sakai · S Tokiguchi · M Takagi ·
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    ABSTRACT: A 4-year-old boy developed bilateral optic neuritis. Although precise neuro-ophthalmological evaluation was difficult, the diagnosis was made with gadolinium-enhanced MR imaging using fat-suppression technique in the initial stage of the disease. Enhancement and enlargement of the intraorbital and intracanalicular optic nerve were demonstrated bilaterally as well as protrusion of the optic nerve head. The disease responded dramatically to intravenous steroid therapy. The etiologies in children usually differ from those in adolescent and adult patients.
    European Radiology 02/1999; 9(4):731-3. DOI:10.1007/s003300050744 · 4.01 Impact Factor
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    K Okamoto · J Ito · I Emura · T Kawasaki · T Furusawa · K Sakai · S Tokiguchi ·
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    ABSTRACT: We report a case of focal orbital amyloidosis involving rectus muscles, which is an extremely rare clinical condition. CT scans showed rectus muscle enlargement with punctate calcifications. Heterogeneous hypointensity was present on T2-weighted MR images, and homogeneous enhancement was seen on fat-saturated contrast-enhanced images of the muscles. These imaging findings seem to be suggestive of amyloidosis. Focal amyloidosis should be included in the differential diagnosis of extraocular muscle enlargement.
    American Journal of Neuroradiology 11/1998; 19(9):1799-801. · 3.59 Impact Factor
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    ABSTRACT: Small cortical enhancing lesions mimicking metastases were demonstrated on contrast imaging in three patients without specific neurologic deficits corresponding to the lesions. One patient had a long carcinoma. However, all had cardiac arrhythmias known as major sources of cerebral emboli. Two had early cerebral infarcts and ischemic heart diseases. The lesions disappeared spontaneously on follow-up studies. They were subsequently presumed to be small infarcts. Clinical information and follow-up examinations are important to differentiate these small cortical lesions from metastases.
    Clinical Imaging 09/1998; 22(5):333-8. DOI:10.1016/S0899-7071(98)00025-4 · 0.81 Impact Factor