Hiroshi Kajikawa

Osaka Medical College, Takatuki, Ōsaka, Japan

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Publications (41)46.31 Total impact

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    ABSTRACT: Background: This study evaluated the rates of new lesions on diffusion-weighted images (DWIs) of magnetic resonance imaging (MRI) and hemorrhagic transformation (HT) during 2 weeks after acute ischemic stroke (AIS) in patients with atrial fibrillation (Af) who were given one of the non-vitamin K antagonist oral anticoagulants (NOACs); this was then compared with those who were given warfarin. Methods and results: Consecutive AIS patients with Af were enrolled between January 2008 and June 2013, and those selected were patients who had a MRI that included DWIs both on admission and after 2 weeks, and those given only wafrarin (warfarin group) or only one of the NOACs (NOAC group) within 2 weeks of admission. Of all 257 enrolled patients, 50 patients were selected for the NOAC group (median age of 80.0 years) and 125 patients for the warfarin group (median age of 80.0 years). Both NOAC and warfarin were started at a median of the second day after admission. There was no significant difference in the rates of new lesions on DWIs (26.0% vs. 28.0%, P=0.7888) and HT (30.0% vs. 39.2%, P=0.2536) between the NOAC and warfarin groups. The NOAC group had a lower rate of concomitant use of heparin (44.0% vs. 92.8%, P<0.0001) than the warfarin group. Conclusions: This study suggests that NOACs are suitable for AIS patients with Af, perhaps even better than warfarin, given their simplicity.
    Circulation Journal 01/2015; 79(4). DOI:10.1253/circj.CJ-14-0793 · 3.94 Impact Factor
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    ABSTRACT: Background The timing of warfarin administration for acute ischemic stroke (AIS) patients with atrial fibrillation (Af) has not been established. We hypothesized that achieving targeted prothrombin time and international normalized ratio (PT-INR) at 2 weeks could prevent AIS patients with Af from developing a new lesion on diffusion-weighted magnetic resonance imaging (DW-MRI). Methods Of consecutively enrolled AIS patients with Af between 2008 and 2011, we selected the patients who were given warfarin within 2 weeks of admission and had DW-MRI and blood test for PT-INR both on admission and at 2 weeks. Warfarin was started as early as possible and heparin was administered until the targeted PT-INR (2.0-3.0 for patients aged <70 years or 1.6-2.6 for those aged ≥70 years) was achieved. Results One hundred and twenty-three patients were selected, consisting of 88 patients without a new lesion and 35 patients with a new lesion. Patients with a new lesion had a significantly higher median score on National Institutes of Health Stroke Scale (11.0 vs. 5.5, P = .0053), a lower rate of achieving targeted PT-INR at 2 weeks (25.7% vs. 48.9%, P = .0190), and a lower median dosage of warfarin at 2 weeks (2.0 mg vs. 2.5 mg, P = .0209) than patients without a new lesion. Multivariate logistic regression analysis showed that failure to achieve targeted PT-INR (P = .0298) was significantly associated with the occurrence of a new lesion. Conclusions Our findings suggest that achieving targeted PT-INR at 2 weeks by using warfarin prevents new lesions in AIS patients with Af.
    Journal of Stroke and Cerebrovascular Diseases 09/2014; 23(8). DOI:10.1016/j.jstrokecerebrovasdis.2014.03.016 · 1.67 Impact Factor
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    ABSTRACT: We encountered a patient with internal carotid artery-posterior communicating artery aneurysm rupture which manifested as acute subdural hematomas not accompanied by subarachnoid hemorrhage. A 92-year-old female suddenly developed severe pain in the area from the left cheek to the forehead. At the time of the first visit to our hospital, neurological examination showed mild left blepharoptosis. Head CT and MRI revealed acute subdural hematomas in the posterior cranial fossa and an interhemispheric fissure, but no subarachnoid hemorrhage. Head MRA showed a left internal carotid artery-posterior communicating artery aneurysm, which had not been present two years previously. There was no history of head injury despite repeated history-taking from the patient and her family. Based on the disease history and findings from imaging and neurological examinations, a diagnosis of acute subdural hematomas due to a ruptured cerebral aneurysm was made, and coil embolization for the aneurysm was performed. Acute subdural hematomas not accompanied by subarachnoid hemorrhage, which are due to ruptured cerebral aneurysms, are rarely observed. In patients with acute subdural hematomas, in the absence of a history of injury, head CT, head MRI and evaluation of cerebral blood vessels may be necessary.
    Nosotchu 01/2014; 36(3):191-196. DOI:10.3995/jstroke.36.191
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    ABSTRACT: We hypothesized that leukocytes have 2 opposing effects on patients with ischemic stroke treated with recombinant tissue plasminogen activator (rtPA). Patients with ischemic stroke treated with rtPA were divided into 2 groups using the peripheral leukocyte count: high leukocyte group (HLG) and low leukocyte group (LLG) and were evaluated with the National Institutes of Health stroke scale (NIHSS) during the first 24 hours. We defined significant improvement (SI) as NIHSS improving by more than 50% from the baseline, and deterioration following improvement (DFI) as the achievement of SI within 24 hours but its subsequent loss at 24 hours. Fifty-three patients were enrolled, and the rate of SI within 24 hours was higher in HLG than in LLG (85.2% vs 42.3%, P = .0011). However, the rate of DFI was significantly higher in HLG than in LLG (29.6% vs 7.7%, P = .0413). We found that leukocytes might have not only deleterious but also beneficial effects in intravenous rtPA treatment.
    Clinical and Applied Thrombosis/Hemostasis 07/2012; 20(1). DOI:10.1177/1076029612452115 · 2.39 Impact Factor
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    ABSTRACT: Intracerebral haemorrhage accompanied with cervical internal carotid artery (ICA) occlusion on the same side without moyamoya-like vessels is rare. A 73-year-old man with left ICA occlusion and no presence of moyamoya disease criteria underwent xenon-enhanced computed tomography with acetazolamide challenge test. The findings showed hypoperfusion and no vasoreactivity in the territory of the left middle cerebral artery. During follow-up he suffered bleeding in the left frontoparietal lobe. Cerebral angiography showed left ICA occlusion and cross flow via the anterior communicating artery without moyamoya vessels. Long-term ischaemia would make perforating or anastomotic arteries vulnerable. These arteries were easily ruptured by hypertension, resulting in intracerebral haemorrhage.
    Neurological Sciences 11/2008; 29(5):367-9. DOI:10.1007/s10072-008-0998-y · 1.45 Impact Factor
  • Skull Base Surgery 09/2008; 18(S 01). DOI:10.1055/s-2008-1093288 · 0.60 Impact Factor
  • International Journal of Cardiology 02/2008; 125. DOI:10.1016/S0167-5273(08)70241-9 · 4.04 Impact Factor
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    ABSTRACT: A 25-year-old woman had a right massive caudate hemorrhage without intraventricular rupture. The patient bled 3 times and underwent resection of the hematoma each time. She was diagnosed finally with an arteriovenous malformation after the third operation. Follow-up magnetic resonance images during intermission-helped guide resection of the lesion.
    Neurosurgery Quarterly 08/2007; 17(3):218-220. DOI:10.1097/WNQ.0b013e31805c0d37 · 0.09 Impact Factor
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    ABSTRACT: Previous studies have shown microbleeds to be a risk factor for intracerebral hemorrhage and white matter hyperintensity (WMH) to be a risk factor for ischemic stroke. This study was performed to determine whether combinations of the presence or absence of microbleeds and advanced WMH are risk factors for subsequent recurrent stroke types. In 266 patients with stroke, microbleeds on T2*-weighted MR images were counted, and WMH on T2-weighted images was graded. Patients were divided into 4 groups by the combinations of the presence or absence of microbleeds and advanced WMH and were followed up for stroke recurrence. During a mean follow-up period of 564.8 +/- 220.5 days, 26 patients developed recurrent strokes, including 10 intracerebral hemorrhages and 16 ischemic strokes. Patients with microbleeds without advanced WMH (n = 42) developed only intracerebral hemorrhages (n = 8), and the recurrence rate of intracerebral hemorrhage in those patients estimated by the Kaplan-Meier method was the highest in the 4 groups (14.3% in 1 year and 21.2% in 2 years). In contrast, patients with advanced WMH without microbleeds (n = 39) developed only ischemic strokes (n = 6), and the estimated recurrent rate of ischemic stroke in those patients was the highest in the 4 groups (10.5% in 1 year and 17.4% in 2 years). Cox proportional hazards regression analysis revealed that microbleeds were associated with intracerebral hemorrhage (hazard ratio [HR], 85.626; 95% confidence interval [CI], 6.344-1155.649) and that advanced WMH was negatively associated with intracerebral hemorrhage (HR, 0.016; 95% CI, 0.001-0.258). Advanced WMH was associated with ischemic stroke (HR, 10.659; 95% CI, 2.601-43.678). It appears that patients at high risk of subsequent intracerebral hemorrhage or ischemic stroke can be identified by combinations of the presence or absence of microbleeds and advanced WMH.
    American Journal of Neuroradiology 05/2006; 27(4):830-5. · 3.59 Impact Factor
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    ABSTRACT: Both leukoaraiosis and asymptomatic microbleeds are associated with small-artery diseases. Although an association between hyperhomocysteinemia and leukoaraiosis has been reported, no studies have evaluated the association between total homocysteine (tHcy) level and presence of microbleeds in stroke patients. We evaluated the association between tHcy level and leukoaraiosis or microbleeds in stroke patients. In 102 patients with stroke (69.5 +/- 10.3 years old, 54 men and 48 women), microbleeds on T2*-weighted MR images were counted, leukoaraiosis on T2-weighted images was graded and fasting plasma tHcy concentrations were measured. Plasma tHcy level was significantly higher in patients with advanced leukoaraiosis than in those without advanced leukoaraiosis (13.9 +/- 4.6 micromol/l vs. 10.2 +/- 3.4 micromol/l, P < 0.0001). Plasma tHcy level was not significantly different in patients with microbleeds and those without microbleeds (11.3 +/- 4.1 micromol/l vs. 11.4 +/- 4.3 micromol/l, P = 0.9441). Elevated tHcy level is significantly and independently associated with advanced leukoaraiosis [odds ratio (OR), 1.330; 95% CI, 1.130-1.565] but not with the presence of microbleeds. Elevated tHcy level appears to be associated with ischemic small-artery disease rather than with bleeding-prone small-artery disease.
    European Journal of Neurology 04/2006; 13(3):261-5. DOI:10.1111/j.1468-1331.2006.01205.x · 4.06 Impact Factor
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    ABSTRACT: We reported two cases of spontaneous intracranial hypotension (SIH) associated with bilateral chronic subdural hematoma (CSDH). The patients presented with severe positional headache, aggravated by sitting or standing. Neither spinal surgery nor lumbar-tap had been performed in these patients. They were diagnosed as SIH with bilateral CSDH. Headache was aggravated and CSDHs volume increased despite conservative therapy. However, after a burr hole irrigation of hematoma, not only CSDHs but also the symptoms with SIH were completely resolved and there was no recurrence. We demonstrated that burr hole irrigation for CSDH associated with SIH might completely resolve the SIH symptom in some cases, as in the present report. The mechanism of this phenomenon was discussed.
    Nō to shinkei = Brain and nerve 09/2005; 57(8):701-7.
  • Nihon Naika Gakkai Zasshi 12/2004; 93(11):2424-6. DOI:10.2169/naika.93.2424
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    ABSTRACT: Asymptomatic microbleeds shown by T2*-weighted MR imaging are associated with small-artery diseases, especially with intracerebral hemorrhage. Few studies have focused on the prevalence of microbleeds in patients with recurrent stroke. We investigated frequency of microbleeds in patients with recurrent stroke and association of presence of microbleeds with a combination of stroke subtypes and severity of leukoaraiosis. The study population consisted of 102 patients with primary stroke and 54 patients with recurrent stroke. Microbleeds were counted and classified by using T2*-weighted MR imaging with a 1.0-T system. Patients with recurrent stroke showed a significantly higher prevalence of microbleeds (68.5%) than did patients with primary stroke (28.4%) (P <.0001). Among patients with recurrent stroke, the highest frequency of microbleeds occurred in those with intracerebral hemorrhage alone (92.3%), with the next highest frequency occurring in those with a combination of intracerebral hemorrhage and ischemic stroke (76.5%) and then those with ischemic stroke alone (50.0%) (P <.05). Leukoaraiosis was more severe in patients with recurrent stroke than in patients with primary stroke, and correlations between grade of microbleeds and severity of leukoaraiosis were found in patients with primary stroke (r = 0.367, P <.001) and in patients with recurrent stroke (r = 0.553, P <.0001). Logistic regression analysis identified recurrent stroke (odds ratio, 4.487; 95% confidence interval, 1.989-10.120) and leukoaraiosis (odds ratio, 5.079; 95% confidence interval, 2.125-12.143) as being significantly and independently associated with microbleeds. Asymptomatic microbleeds are observed to occur frequently in patients with recurrent stroke, either hemorrhagic or ischemic stroke, and are closely associated with the severity of leukoaraiosis.
    American Journal of Neuroradiology 06/2004; 25(5):714-9. · 3.59 Impact Factor
  • E Nomura · T Kohriyama · K Kozuka · H Kajikawa · S Nakamura · M Matsumoto
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    ABSTRACT: The purpose of the present study was to investigate sequential changes in serum soluble thrombomodulin (sTM) concentrations in patients with acute cerebral infarction (ACI), and to correlate sTM concentrations with the severity of ACI evaluated by Japan Stroke Scale. Eighty-three consecutive patients with ACI were enrolled, and blood examinations were carried out soon after admission and 1 month after. sTM concentrations at admission in patients with cardioembolic infarction (3.2 +/- 1.2 ng/ml) were significantly lower than those of lacunar infarction (3.9 +/- 1.2) (P < 0.05). Serial examinations revealed that sTM concentrations increased significantly 1 month after admission (3.8 +/- 1.2), compared with those at admission (3.6 +/- 1.2) (P = 0.02). Of three ACI subtypes, sTM concentrations during 1 month significantly increased in atherothrombotic infarction (P = 0.002) or, not significantly, in cardioembolic infarction (P = 0.09). The sTM concentrations at admission showed a significant inverse correlation with the severity of ACI (P = 0.04). Although sTM concentrations serve as a useful marker for endothelial cell damage, they are decreased in patients with severe ACI, especially in atherothrombotic and cardioembolic infarctions. Lower sTM concentrations may play some important role in disease progression or in the recurrence following ACI, although the exact mechanism of this unique result should be clarified.
    European Journal of Neurology 06/2004; 11(5):329-34. DOI:10.1111/j.1468-1331.2004.00776.x · 4.06 Impact Factor
  • Nō to shinkei = Brain and nerve 12/2003; 55(11):990-1.
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    ABSTRACT: Multivariate and single variable analyses were employed to investigate the recovery mode of aphasia in right-handed patients with putaminal hemorrhage on the left side. Speech disturbance was evaluated using the standard language test for aphasia (SLTA) at intervals of 1, 3 and 6 months after the ictus. Recovery was assessed in relation to age, gender, volume and location of hematoma, and treatment modalities. Extension of the hematoma into the corona radiata was the factor that dominated the prognosis of aphasia at all intervals during the follow-up period. Good recovery was documented in patients with less than 2 cm2 of the hematoma volume located in the corona radiata. Recovery was poor, however, in patients with more than 12 cm2 of the hematoma in the corona radiata. While aphasia continued to improve over 6 months after the ictus, recovery was more prominent in the first 3 months. Our study precisely demonstrated that the extension into the corona radiata independently and strongly influenced the outcome of aphasia in patients with left putaminal hemorrhage.
    Neurological Research 01/2003; 24(8):817-21. DOI:10.1179/016164102101200780 · 1.44 Impact Factor
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    ABSTRACT: The progress of a stroke concerns the activation of endothelial cells and platelets. We measured the plasma activities of von Willebrand factor (vWf) and the serum levels of soluble thrombomodulin (sTM) as endothelial markers, and the plasma concentrations of soluble P-selectin (sP-selectin) and soluble E-selectin (sE-selectin) as adhesion molecules during the acute (within 48 h from onset) and subacute (after 1 month from the onset) phases of 52 consecutive patients with acute ischemic stroke and 86 age-matched control subjects. The plasma vWf activities and levels of sP-and sE-selectins in stroke patients were significantly elevated compared with those in controls during both the acute and subacute phases. The serum levels of sTM in stroke patients were significantly higher than those in controls only during the subacute phase. In atherothrombotic infarction, the vWf activities and the levels of sP-selectin, markers for endothelial and platelet activation, remained higher until the subacute phase compared with controls, and the concentrations of sTM, a marker for endothelial injury, were increased during the subacute phase compared with during the acute phase. In lacunar infarction, the levels of sTM and sE-selectin of patients were higher only during the acute phase than controls. These findings suggest that the endothelial cell damage might be maintained until the subacute phase in atherothrombotic infarction, whereas it is remarkable only during the acute phase in lacunar infarction. The evaluation of endothelial markers and adhesion molecules would represent the pathophysiological states of stroke and may provide useful information for the treatment of the ischemic infarction.
    Atherosclerosis 04/2002; 161(1):161-8. DOI:10.1016/S0021-9150(01)00635-9 · 3.99 Impact Factor
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    ABSTRACT: The purposes of the present study were to investigate sequential changes in plasma von Willebrand factor (vWf) activities and serum soluble thrombomodulin (sTM) concentrations, compared with white blood cell (WBC) counts, and to disclose the different roles of vWf and sTM in acute ischemic stroke. Forty-three acute ischemic stroke patients admitted to our hospital within 48 hours from onset were enrolled. Plasma vWf activities, serum sTM concentrations, and WBC counts were measured at the acute stage and 1 and 6 months after admission. The time course study revealed that vWf activities increased more markedly 1 month after admission than at the acute stage. However, sTM concentrations were low at the acute stage and increased sequentially at 1 month (not significantly) and 6 months (significantly) after admission. In contrast, elevated WBC counts at the acute stage decreased significantly at 1 and 6 months after admission. Raised vWf activities 1 month after admission were suggested to occur through continuous endothelial dysfunction or repair and platelet activation, compared with the acute stage, and decreased sTM at the acute stage through down-regulation of sTM synthesis by acute inflammatory response after acute ischemic stroke, compared with the chronic stage.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 11/2001; 10(6):257-64. DOI:10.1053/jscd.2001.123776 · 1.67 Impact Factor
  • Nosotchu 01/2001; 23(3):234-239. DOI:10.3995/jstroke.23.234
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    ABSTRACT: We investigated changes of the blood pressure in 29 stroke patients before stroke recurrence and after recurrence. Additional antihypertensive drugs were not administered to all patients after stroke recurrence. Twenty-five lacunar infarct patients and 4 atherothrombotic infarct patients were included in this study. A significant difference was observed between the systolic blood pressure(SBP) within 4 weeks before recurrence and that just after recurrence(132.8 +/- 17.2 mmHg vs. 157.4 +/- 21.3 mmHg, Wilcoxon rank sum test, p < 0.001), or between the SBP just after and 2 weeks after stroke recurrence(157.4 +/- 21.3 mmHg vs. 138.0 +/- 18.3 mmHg, Wilcoxon rank sum test, p < 0.001). The similar difference was found in the diastolic blood pressure(DBP) or in the mean arterial blood pressure(MABP). There was no significant difference in the SBP, the DBP or the MABP between the patients before and 2 weeks after the stroke recurrence. These results suggested that the elevation of the blood pressure at recurrence decreased spontaneously to the pre-recurrence level of the blood pressure in about 2 weeks.
    Nō to shinkei = Brain and nerve 12/2000; 52(11):984-9.

Publication Stats

247 Citations
46.31 Total Impact Points


  • 1998
    • Osaka Medical College
      • Department of Neurosurgery
      Takatuki, Ōsaka, Japan
  • 1996–1998
    • Hiroshima University
      • School of Medicine
      Hirosima, Hiroshima, Japan