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Dive into the research topics where Toshiyasu Ogata is active.

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Featured researches published by Toshiyasu Ogata.


Journal of Ultrasound in Medicine | 2005

Atherosclerosis Found on Carotid Ultrasonography Is Associated With Atherosclerosis on Coronary Intravascular Ultrasonography

Toshiyasu Ogata; Masahiro Yasaka; Masakazu Yamagishi; Osamu Seguchi; Kazuyuki Nagatsuka; Kazuo Minematsu

Little has been reported on the relationship between left main coronary artery atherosclerosis and carotid ultrasonographic results. We evaluated the association between carotid and coronary atherosclerosis assessed by coronary intravascular ultrasonography (IVUS) in 45 patients.


Journal of the Neurological Sciences | 2008

Deep venous thrombosis after acute intracerebral hemorrhage

Toshiyasu Ogata; Masahiro Yasaka; Yoshiyuki Wakugawa; Tooru Inoue; Setsuro Ibayashi; Yasushi Okada

BACKGROUND We evaluated the incidence of deep venous thrombosis (DVT) and the characteristics of patients with acute ICH who developed DVT. METHODS We enrolled 52 patients with acute ICH between June 2005 and September 2006. We recorded their stroke risk factors, neurological deficit, hemorrhage size and laboratory data, and performed ultrasonography to detect DVT within 72 h of onset of ICH and after two weeks. RESULTS DVT was detected a total of 21 patients (40.4%) after two weeks. Patients with DVT tended to be older, and had significantly more severe disturbance of consciousness (p=0.020) and paralysis (p=0.035) on admission than those without DVT. The National Institutes of Health Stroke Scale (NIHSS) score was significantly higher in patients with DVT than those without (p=0.002). Patients with a larger diameter of ICH were more likely to develop DVT (p=0.021). D-dimer value on admission was significantly higher in patients with DVT than those without (p=0.002). Logistic regression analysis indicated that both NIHSS score and D-dimer value were independent risk factors for the occurrence of DVT. CONCLUSIONS We need be aware that acute ICH patients with severe neurological deficit and high D-dimer value are at increased risk of developing DVT.


Journal of Stroke & Cerebrovascular Diseases | 2008

Cerebral Venous Thrombosis Associated With Iron Deficiency Anemia

Toshiyasu Ogata; Masahiro Kamouchi; Takanari Kitazono; Junya Kuroda; Hiroaki Ooboshi; Tadahisa Shono; Takato Morioka; Setsuro Ibayashi; Tomio Sasaki; Mitsuo Iida

A 55-year-old man presented with generalized seizures and postictal left hemiparesis. Computed tomography scanning of his head showed a low density area in the right frontal lobe. Cerebral angiography demonstrated a partial defect in the superior sagittal sinus and cortical veins, indicating the presence of cerebral venous thrombosis. He had bleeding from a peptic ulcer and the laboratory data revealed iron deficiency anemia concomitant with an elevation of D-dimer and thrombin-antithrombin III complex (TAT). After the anemia resolved with the treatment of the peptic ulcer and iron supplementation, the TAT and D-dimer levels were normalized, and the occluded veins were recanalized. In a cerebral venous thrombosis associated with iron deficiency anemia, treatment for the anemia may improve hypercoagulable state without antithrombotic therapy, although the long-term monitoring of TAT and D-dimer levels is required.


Cerebrovascular Diseases | 2010

Morphological classification of mobile plaques and their association with early recurrence of stroke.

Toshiyasu Ogata; Masahiro Yasaka; Yoshiyuki Wakugawa; Takanari Kitazono; Yasushi Okada

Background: The present study investigated the frequency and morphological characteristics of carotid mobile plaques and examined the relationship between carotid mobile plaques and recurrent strokes. Methods: The study included 94 consecutive acute stroke patients with large-artery atherosclerosis associated with extracranial carotid stenosis. We investigated the presence of mobile plaques by carotid ultrasonography and classified patients into two groups (mobile group and non-mobile group). We compared backgrounds, MRI and ultrasonographic findings, neurological severity on admission and at discharge, and the rate of early recurrent stroke between both groups. Results: Mobile plaques were detected in 12 patients (12.8%). There were four types of mobile plaques: (1) the jellyfish-type plaque, in which the fibrous cap fluctuated like a jellyfish; (2) the streaming-band-type plaque, in which the string attached to the plaque was swaying; (3) the mobile-thrombus-type plaque, in which a mobile mass was attached to the plaque surface, and (4) the fluctuating-ulcer-type plaque, which contained a mobile substance in the plaque ulcer. Although National Institutes of Health Stroke Scale (NIHSS) scores on admission were less severe in the mobile group than in the non-mobile group (median 1 vs. 4, respectively; p = 0.004), the rate of early recurrent stroke was significantly higher in the mobile group than in the non-mobile group (33.3 vs. 7.3%, respectively; p = 0.022). There were no significant differences in NIHSS scores at discharge between groups. Conclusions: Morphologically, several types of mobile plaques were detected in consecutive patients with acute stroke associated with carotid stenosis. Mobile plaques are strongly associated with an early recurrence of stroke.


Angiology | 2009

Angiographic characteristics of radiation-induced carotid arterial stenosis.

Takashi Shichita; Toshiyasu Ogata; Masahiro Yasaka; Kotaro Yasumori; Tooru Inoue; Setsuro Ibayashi; Mitsuo Iida; Yasushi Okada

Purpose: This study aimed to clarify the angiographic characteristics of radiation-induced carotid stenosis. Methods: We evaluated 11 carotid arteries of patients after radiotherapy (radiotherapy group) and 26 carotid arteries of age- and gender-matched patients without a history of radiotherapy (control group). All patients had carotid stenosis detected by digital subtraction angiography (DSA). We developed an original coordinate system on the DSA to determine the accurate length and location of the carotid lesion. Results: Radiation-induced carotid lesions were significantly longer than carotid lesions caused by atherosclerosis. The maximal stenosis of radiation-induced carotid lesions tended to be at the end of the stenotic area and within a wider range than the nonradiation-induced lesions, including in the proximal common carotid artery (CCA). Conclusions: Radiation-induced stenotic lesions seem to exist in a wide range of carotid artery, including the CCA, along the vessel, and show maximal stenosis near the end of the stenotic area.


Journal of the Neurological Sciences | 2004

Variation in ischemic stroke frequency in Japan by season and by other variables

Toshiyasu Ogata; Kazumi Kimura; Kazuo Minematsu; Seiji Kazui; Takenori Yamaguchi

BACKGROUND AND PURPOSE It is unclear whether acute ischemic stroke exhibits a seasonal pattern in Japan. The aim of the present study was to elucidate seasonal differences in acute ischemic stroke. METHODS Our study enrolled 12,660 patients with ischemic stroke (7943 men, 4717 women; mean age, 70.1 years, S.D. 11.5; median 70; range 18-107). We divided the year into four parts: spring (March-May); summer (June-August); fall (September-November); and winter (December-February). Time of stroke onset was divided into three subgroups: daytime (08:00-16:00), evening (16:00-24:00), and night (24:00-08:00). We examined the association between clinical characteristics, season, and time of stroke onset. RESULTS Stroke occurred least frequently in spring (22.9%), followed by winter (25.3%), fall (25.8%), and summer (26.0%) (P<0.001). No differences in age, National Institutes of Health Stroke Scale (NIHSS) score, modified Rankin Scale (m-RS) score, history of stroke/transient ischemic attack (TIA), or risk factors for stroke were observed among the four seasons. Stroke in men (63.8% vs. 62.4%; P<0.01), lacunar stroke (LS) (41.2% vs. 39.4%, P<0.01), atherothrombotic stroke (ATS) (34.0% vs. 32.3%; P<0.01), and nighttime stroke (26.5% vs. 24.8%; P<0.05) were observed more frequently in summer compared to other seasons. This contrasts with the findings for stroke in women (39.0% vs. 36.7%; P<0.05), cardioembolic stroke (CES) (23.4% vs. 20.6%; P<0.05), and daytime stroke (47.4% vs. 45.0%; P<0.05), which were more frequent in winter. CONCLUSIONS Acute ischemic stroke displays seasonal characteristics according to gender, stroke subtype, and time of stroke onset. These results may have important clinical implications in ischemic stroke prevention.


Journal of Ultrasound in Medicine | 2006

Bottle Neck Sign of the Proximal Portion of the Internal Carotid Artery in Moyamoya Disease

Masahiro Yasaka; Toshiyasu Ogata; Kotaro Yasumori; Tooru Inoue; Yasushi Okada

Objective. We investigated morphologic features of the extracranial internal carotid artery (ICA) by carotid ultrasonography in patients with moyamoya disease. Methods. We performed conventional carotid ultrasonography and transoral carotid ultrasonography on 19 ICAs in 10 patients with moyamoya disease (moyamoya group) and 28 ICAs in 14 control subjects (control group). We evaluated whether the diameter was greatly reduced at the proximal portion of the ICA above the bulbus, like a champagne bottle neck, to be less than half that of the common carotid artery and whether the diameter of the ICA was smaller than that of the external carotid artery (diameter reversal) on conventional carotid ultrasonography. We then measured the internal diameter of the extracranial distal ICA by transoral carotid ultrasonography. We compared the incidence of a “bottle neck” appearance, diameter reversal, and the ICA diameter between the 2 groups. Results. The bottle neck and diameter reversal were shown in 14 (74%) and 16 (84%) of the 19 ICAs in the moyamoya group, respectively (χ2 test, P < .0001). However, neither of them was shown in the control group. The diameter of the distal ICA in the moyamoya group was significantly smaller than that in the control group (mean ± SD, 2.4 ± 0.60 versus 4.1 ± 0.52 mm; unpaired t test, P < .0001). Conclusions. These results suggest that rapid internal diameter reduction at the proximal portion of the ICA, characterized by a bottle neck appearance or diameter reversal, is an important morphologic feature of moyamoya disease.


Journal of the Neurological Sciences | 2009

Predisposing factors for acute deterioration of minor ischemic stroke

Toshiyasu Ogata; Masahiro Yasaka; Yoshiyuki Wakugawa; Setsuro Ibayashi; Yasushi Okada

PURPOSE Since attention should be paid to acute stroke patients who may easily worsen, we investigated the predisposing factors for acute deterioration of minor ischemic stroke in Japanese patients. METHODS We retrospectively investigated 543 patients who were admitted within 7 days of the occurrence of an acute minor stroke with National Institute of Health Stroke Scale (NIHSS) score of 4 or less, between January 2002 and September 2005. Deterioration of neurological findings was defined as the worsening by 2 points or more of the NIHSS score during admission to the hospital. RESULTS Out of 543 patients, deterioration was noted in 37 patients (6.8%: deterioration group), and not in the other 506 patients (93.2%: non-deterioration group). Multivariate analysis demonstrated that the factors associated with worsening were atherothrombotic brain infarction (deterioration group vs. non-deterioration group: 35.1% vs. 18.0%, P=0.049), elevated systolic blood pressure (170.5+/-32.4 mm Hg vs. 160.4+/-27.4 mm Hg, P=0.033), serum glucose level on admission (146.1+/-60.5mg/dL vs. 121.7+/-54.9 mg/dL, P=0.048), and presence of paralysis (73.0% vs. 54.9%, P=0.003) and vertigo (16.2% vs. 7.9%, P=0.034). The more factors there were that were associated with worsening (atherothrombotic infarction; systolic blood pressure >140 mm Hg; serum glucose level >140 mg/dL; and paralysis, vertigo, and dizziness), the more frequently the deterioration occurred (number of worsening factors 0-2: 4.6%, 3: 12.8%, 4: 32.3%). Although over 80% of patients in the group without deterioration had good functional outcome at discharge, over 90% of patients with deterioration either were discharged to nursing home care or died. CONCLUSION In this study, the predisposing factors for acute deterioration in minor ischemic stroke were atherothrombotic brain infarction; high blood pressure; elevated serum glucose level; and paralysis, vertigo, and dizziness. Once patients with minor ischemic stroke deteriorated, their functional outcome at discharge was significantly worse than those who had not deteriorated.


Journal of Stroke & Cerebrovascular Diseases | 2012

Long-term results of medical and surgical therapy for Japanese patients with moderate carotid stenosis.

Toshiyasu Ogata; Masahiro Yasaka; Yoshiyuki Wakugawa; Tooru Inoue; Kotaro Yasumori; Takanari Kitazono; Mitsuo Iida; Yasushi Okada

To clarify the efficacy of medication versus carotid endarterectomy (CEA), we investigated cardiovascular events and outcomes in Japanese patients with moderate carotid stenosis. We consecutively registered patients with significant carotid stenosis (50%-79%) measured by digital subtraction angiography (DSA) over 10 years and compared the incidences of stroke, myocardial infarction, and death between treatment groups (surgical group vs medical group). Of 406 registered patients, 163 (108 treated surgically and 55 treated medically) with moderate carotid stenosis were analyzed. Complete follow-up data (mean, 4.2 years) were available for 105 patients in the surgical group (97.2%) and 54 patients in the medical group (98.2%). Surgical treatment was associated with lower incidences of any stroke, myocardial infarction, and death compared with medication. Although the incidence rates differed significantly between CEA and medication in the 66 symptomatic patients, there were no significant differences in the 93 asymptomatic patients. The results of this single-center study in Japanese patients suggest that CEA is an acceptable treatment for patients with symptomatic moderate carotid stenosis, but that CEA for asymptomatic moderate carotid stenosis seems to be less effective in Japanese patients.


Assistive Technology | 2016

Tailor-made rehabilitation approach using multiple types of hybrid assistive limb robots for acute stroke patients: A pilot study

Hiroyuki Fukuda; Takashi Morishita; Toshiyasu Ogata; Kazuya Saita; Koichi Hyakutake; Junko Watanabe; Etsuji Shiota; Tooru Inoue

ABSTRACT This article investigated the feasibility of a tailor-made neurorehabilitation approach using multiple types of hybrid assistive limb (HAL) robots for acute stroke patients. We investigated the clinical outcomes of patients who underwent rehabilitation using the HAL robots. The Brunnstrom stage, Barthel index (BI), and functional independence measure (FIM) were evaluated at baseline and when patients were transferred to a rehabilitation facility. Scores were compared between the multiple-robot rehabilitation and single-robot rehabilitation groups. Nine hemiplegic acute stroke patients (five men and four women; mean age 59.4 ± 12.5 years; four hemorrhagic stroke and five ischemic stroke) underwent rehabilitation using multiple types of HAL robots for 19.4 ± 12.5 days, and 14 patients (six men and eight women; mean age 63.2 ± 13.9 years; nine hemorrhagic stroke and five ischemic stroke) underwent rehabilitation using a single type of HAL robot for 14.9 ± 8.9 days. The multiple-robot rehabilitation group showed significantly better outcomes in the Brunnstrom stage of the upper extremity, BI, and FIM scores. To the best of the authors’ knowledge, this is the first pilot study demonstrating the feasibility of rehabilitation using multiple exoskeleton robots. The tailor-made rehabilitation approach may be useful for the treatment of acute stroke.

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Toshio Higashi

Memorial Hospital of South Bend

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