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Toshiyasu Ogata

Publications and source records attributed to Toshiyasu Ogata.

13 recordsLinked to original sources
PubMed2007

[Prevention of brain infarction in patients with atrial fibrillation].

The patients with cardioembolic stroke sometimes suffer from severe neurological deficit and from recurrent strokes. Since atrial fibrillation, especially non-valvular atrial fibrillation (NVAF) is associated with over half of the cardioembolic strokes, the prevention of cardioembolic stroke in patients with NVAF is important. There have been some reports about how to prevent stroke. They have indicated that the best medication for preventing from stroke was anticoagulation by warfarin. Therefore, the guidelines recommended the patients with NVAF to take warfarin. In case with the older patients under 70 years, prothrombin international normalized ratio (PT-INR) should be kept from 2.0 to 3.0. On the other hand, if the patients with NVAF are over 70 years, PT-INR has to be controlled from 1.6 to 2.6. Before extraction of a tooth, anticoagulation should not be call off.

Age Factors↗
PubMed2006

Factors associated with occurrence of the intraleft atrial nonsmoke spontaneous individual contrast phenomenon after a Valsalva maneuver during transesophageal echocardiography.

Nonsmoke spontaneous individual contrast (NSSIC) is a phenomenon that is a contrast effect appearing from the right pulmonary vein to the left atrium just after a Valsalva maneuver in a transesophageal echocardiography study without administration of any contrast medium. The goal of this study was to characterize factors associated with occurrence of NSSIC. Transesophageal echocardiography was performed in 228 consecutive patients to determine the presence or absence of the patent foramen ovale and valvular disease and various patient characteristics and laboratory data. NSSIC was demonstrated in 109 (47.8%) of 228 patients. Factors associated with occurrence of NSSIC included younger age, male gender, smoking habit, taller height, heavier weight, higher hematocrit, higher plasma level of fibrinogen, lower D-dimer levels and presence of mitral valve strand. Multiple logistic regression analysis indicated that higher hematocrit and plasma levels of fibrinogen were most closely associated with the presence of NSSIC. Thus, NSSIC may occur secondary to specific blood rheologic factors during the Valsalva maneuver.

Age Factors↗
PubMed2006

Bottle neck sign of the proximal portion of the internal carotid artery in moyamoya disease.

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 (chi2 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.

Adolescent↗
PubMed2005

Diagnosis of middle cerebral artery occlusive lesions with contrast-enhanced transcranial color-coded real-time sonography in acute stroke.

It is useful to evaluate the occlusive lesions of middle cerebral artery (MCA) occlusion with transcranial color-coded real-time sonography (TCCS). However, TCCS criteria for locating the site of the MCA occlusion has, as yet, remained unclear. The aim of the present study was to establish TCCS criteria for MCA occlusive lesions. We prospectively performed contrast-enhanced TCCS (CE-TCCS) in 75 consecutive acute stroke patients within 24 h of digital subtraction angiography. Patients were divided into four groups: occlusion of the MCA stem (MO group, n=12); occlusion of the MCA branch (MBO group, n=10); stenosis of the MCA stem (MS group, n=9); and no occlusive or stenotic lesions (control group, n=44). The following parameters were measured: peak systolic velocity (PSV) and end diastolic velocity (EDV) of bilateral MCA stems, and ED-ratio (the side-to-side ratio of the EDV). We establish the CE-TCCS criteria for MCA occlusive lesions using the sensitivity-specificity curve analysis. A PSV of 170 cm/s distinguished MCA stenosis from other groups (positive and negative predictive values and the accuracies were 100%, 99.0% and 99.1%, respectively). An EDV of 26 cm/s differentiated MO or MBO from the other groups (positive and negative predictive values and the accuracies were 84.6%, 100% and 96.5%, respectively). An ED-ratio of 2.5 discriminated MO from the MBO group (positive and negative predictive values and the accuracies were 88.9%, 85.7% and 87.5%, respectively). Measurement of MCA stem flow velocity with CE-TCCS can identify MCA stem stenosis and occlusion, as well as MCA branch occlusion.

Aged↗
PubMed2005

Atherosclerosis found on carotid ultrasonography is associated with atherosclerosis on coronary intravascular ultrasonography.

OBJECTIVE: 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. METHODS: We counted the number of plaques with intima-media thickness (IMT) greater than or equal to 1.1 mm and calculated a plaque score by summing all plaque thicknesses. With the use of IVUS, the percent plaque area was calculated at the proximal, middle, and distal sites of the left main coronary artery. The maximum percent plaque area and mean percent plaque area of the 3 sites were also calculated. Relationships among the degree of left main coronary artery atherosclerosis and carotid atherosclerosis and vascular risk factors were evaluated. RESULTS: The mean percent plaque area and maximum percent plaque area were increased in men and in patients with hypertension compared with women and those without hypertension (P < .1). Both the average of the maximum common carotid IMT and plaque number were correlated with both the mean percent plaque area and maximum percent plaque area (P < .05). Men, the presence of hypertension, and the average of the maximum common carotid IMT were correlated with both the mean percent plaque area and maximum percent plaque area by multiple linear regression analysis (P < .05). CONCLUSIONS: The average of the maximum common carotid IMT was significantly correlated with left main coronary artery atherosclerosis evaluated by IVUS.

Arteriosclerosis↗
PubMed2004

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

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.

Adolescent↗
PubMed2004

Relationships between angiographic findings and National Institutes of Health stroke scale score in cases of hyperacute carotid ischemic stroke.

BACKGROUND AND PURPOSE: Stroke severity in cases of hyperacute carotid ischemic stroke may be related to site of arterial occlusion. We evaluated the relationships between National Institutes of Health Stroke Scale (NIHSS) scores and findings on intra-arterial digital subtraction angiograms (IA-DSA) of patients with ischemic stroke within 6 hr of stroke onset. METHODS: A total of 43 consecutive patients (38 men and five women; mean age, 69.4 +/- 8.7 years) with ischemic stroke in the carotid territory underwent IA-DSA within 6 hr of stroke onset. Baseline NIHSS score was assessed immediately before IA-DSA. Patients were divided into four groups according to site of arterial occlusion: 1) the internal carotid artery (ICA group, n = 10); 2) stem of the middle cerebral artery or stem of the anterior cerebral artery (Stem group, n = 14); 3) branches of middle cerebral artery or anterior cerebral artery (Branch group, n = 11); and 4) no arterial occlusion (Normal group, n = 8). RESULTS: Mean (+/-SD) NIHSS score was 14.7 +/- 7.4. The interval from stroke onset to IA-DSA study was 205 +/- 76 min. NIHSS score was higher in the ICA group (median, 23; range, 6-32) than in the Branch (median, 17; range, 11-25; P =.02) or Normal (median, 15; range, 2-17; P <.001) groups but was not higher than in the Stem group (median, 6; range, 1-11; P =.73). Sensitivity-specificity curve analysis suggested an NIHSS score > or = 10 as indicative of arterial occlusion of the carotid system. A total of 96.9% of patients with NIHSS scores > or = 10 displayed arterial occlusion, and 63.6% of patients with NIHSS scores <10 displayed no arterial occlusion. CONCLUSION: NIHSS score is related to site of arterial occlusion in cases of hyperacute carotid ischemic stroke. An NIHSS score of 10 seems to represent the cut-off for discriminating between patients with arterial occlusion and patients without.

Aged↗
PubMed2003

[A case of hypoxic brain damage induced by severe asthma successfully treated by hypothermia therapy].

We experienced a case of hypoxic brain damage induced by severe asthma who was successfully treated by hypothermia. A 20-year-old woman with a history of bronchial asthma suffered from severe respiratory distress and she stopped breathing for about 20 minutes. She was admitted to our hospital with respiratory arrest, deep coma, mydriasis and weak motor response to pain. She was intubated and mechanically ventilated with 100% oxygen. She was cooled down to 33 degrees C within 4 hours of her arrival. Her body temperature was maintained at about 33 degrees C for 2 days, and then gradually rewarmed. During hypothermia, PaCO2 was quite high(80-100 mmHg), but the intracranial pressure was kept low. After hypothermia therapy, she became free from consciousness disturbance and there were no neurological disorders except for mild myoclonus. Hypothermia has a possibility of effective therapy for patients with hypoxic brain damage after respiratory distress.

Adult↗
PubMed2002

[Association between carotid artery diameter and aortic aneurysm].

Although it has been suggested that an increase in arterial diameter is related to atherosclerotic risk factors, there are only a few reports about the relationship between the diameter of the common carotid artery(CCA) and the presence of aortic aneurysm (AA). We measured CCA diameters by carotid ultrasonography in 132 consecutive AA patients over 40 years of age (aneurysm group), and in 414 consecutive subjects over 40 years of age without AA (control group). We also studied the size of AA based on CT, MRA or surgical findings. We compared CCA diameters with atherosclerotic risk factors between the two groups, and studied the relationship between the CCA diameters and AA size by types of aneurysm. In the aneurysm group, men (85% vs 69%, p < 0.001), hypertension (88% vs 67%, p < 0.001) and smoking (63% vs 46%, p < 0.001) were more frequent, and the diameter of the CCA (right, 7.0 +/- 1.1 mm vs 6.3 +/- 1.0 mm, p < 0.001; left, 6.7 +/- 1.1 mm vs 6.1 +/- 1.0 mm, p < 0.001) was significantly larger than those in the control group. Multiple logistic regression analysis indicated that dilatation of CCA on either side was a significant risk factor for AA (right, odds ratio 1.69, p < 0.001, left, odds ratio 1.48, p < 0.001) as well as hypertension and smoking. There were no differences in size of the CCA according to the site of aneurysm. However the CCA diameter was significantly related to the size of the thoracic AA (r = 0.350, p < 0.05 for the right CCA) and dissecting AA (r = 0.506, p < 0.05 for the left CCA). In conclusion, the increase in CCA diameter may suggest the presence of AA, and CCA diameter appears to be related to AA size.

Adult↗
PubMedDate not supplied

Transcranial color-coded real-time sonographic criteria for occlusion of the middle cerebral artery in acute ischemic stroke.

BACKGROUND AND PURPOSE: Transcranial color-coded real-time sonography (TCCS) is a useful tool to evaluate disease of the middle cerebral artery (MCA). This study was undertaken to identify TCCS criteria for the diagnosis of MCA stem and MCA branch occlusions. METHODS: TCCS and digital subtraction angiography were performed in 55 consecutive patients with acute stroke: 10 with MCA stem occlusion, the MO group; eight with MCA branch occlusion, the MB group; and 37 with nonocclusive lesions, the control group. We measured the end-diastolic velocity (EDV) of the bilateral MCA stems and calculated the end-diastolic ratio by dividing the EDV of the unaffected side by that of the affected side. RESULTS: EDV was highest in the control group, and end-diastolic ratio was highest in the MO group. An EDV of >25 cm/s indicated a nonocclusive lesion in the MCA, with a positive predictive value of 98.4%, a negative predictive value of 81.0%, and an accuracy of 93.9%. An EDV of or=2.7 indicated MCA stem occlusion with a positive predictive value of 100%, a negative predictive value of 100%, and an accuracy of 100%. CONCLUSION: We developed TCCS criteria for the diagnosis of MCA diseases. MCA flow velocity detected by means of TCCS can help identify MCA stem occlusion as well as MCA branch occlusion.

Aged↗