Atsushi Murakata

St. Luke's International Hospital, Edo, Tōkyō, Japan

Are you Atsushi Murakata?

Claim your profile

Publications (11)28.14 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objectives For patients with non-traumatic pontine hemorrhage (PH) who will survive, determining prognosis is vital for appropriate therapeutic planning in the acute stage. This study aimed to determine reliable prognostic factors of mortality in patients with PH.Materials and methodsThe cases of a total of 118 consecutive PH patients were reviewed. We compared clinical and radiological characteristics between patients who died and survivors by the log-rank test and performed multivariate analysis by the Cox proportional hazards model using variables that were marginally or significantly associated with PH-related death on the log-rank test (P < 0.20).ResultsThe median length of follow-up was 51 days (interquartile range: 7–742 days). Sixty-six patients (56%) died and 52 (44%) survived during follow-up period. Multivariate analysis showed that Glasgow Coma Scale score <9, hyperthermia (a core temperature of ≥39°C), maximum hematoma diameter more than 27 mm, and hematoma extension to midbrain and/or thalamus were significantly related to PH-related death. The Kaplan–Meier method showed that patients without these four factors had successively longer period at PH-related death (21 patients without factors: mean 2900 days; 97 patients with at least one of four factors: mean 820 days).Conclusions Promptly identifying PH patients who are most likely die is important. The decision to stop life support in patients with PH is difficult, but factors, which are shown in this study, may be used to determine the level of care.
    Acta Neurologica Scandinavica 09/2014; · 2.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Objective: The influence of blood alcohol level (BAL) on outcome remains unclear. This study investigated the relationships between BAL, type and number of diffuse axonal injury (DAI), intraventricular bleeding (IVB) and 6-month outcome. Methods: This study reviewed 419 patients with isolated blunt traumatic brain injury. First, it compared clinical and radiological characteristics between patients with good recovery and disability. Second, it compared BAL among DAI lesions. Third, it evaluated the correlation between the BAL and severity of IVB, number of DAI and corpus callosum injury lesions. Results: Regardless of BAL, older age, male gender, severe Glasgow Coma Scale score (<9), abnormal pupil, IVB and lesion on genu of corpus callosum were significantly related to disability. There were no significant differences between the BAL and lesions of DAI. Simple regression analysis revealed that there were no significant correlation between BAL and severity of IVB, number of DAI and corpus callosum injury lesions. Conclusions: Acute alcohol intoxication was not associated with type and number of DAI lesion, IVB and disability. This study suggested that a specific type of traumatic lesion, specifically lesion on genu of corpus callosum and IVB, might be more vital for outcome.
    Brain Injury 10/2013; · 1.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Patients with spontaneous intradural vertebral artery dissection (siVAD) developing subarachnoid hemorrhage (SAH) have been observed to have poor outcomes. Factors predisposing siVAD patients to SAH are not well known. We aimed to investigate the clinical and vertebrobasilar artery morphological characteristics associated with SAH in patients with siVAD. Methods: We reviewed 103 consecutive patients with siVAD managed at our facility between July 2003 and June 2012. We divided the patients into groups, with (n = 22) and without (n = 81) SAH, and compared clinical and vertebrobasilar artery morphological characteristics between them. The vertebral-union-basilar angle (VUBA) was defined as the most acute angle between the line of the basilar artery trunk and the line of the vertebral artery at the vertebral union on 3-dimensional magnetic resonance angiography, computed tomographic angiography, or digital subtraction angiography. 'Steep vertebral artery' was defined as VUBA >45°. Basilar artery bending was defined as the longest distance from the line which connected the basilar top and vertebral artery union to the greatest bending point of the basilar artery. Results: Stepwise logistic regression analysis was performed using variables that were marginally or significantly associated with SAH on univariate analysis (p < 0.10) and that were thought to be clinically important for SAH. It showed SAH patients to have significantly higher proportions of current smoking (OR: 7.7; 95% CI: 2.7-22; p = 0.0015), dissection of the dominant vertebral artery (OR: 4.9; 95% CI: 1.8-13; p = 0.043), steep vertebral artery of the dissecting side (OR: 7.2; 95% CI: 2.6-20; p = 0.0023), posterior inferior cerebellar artery involvement (OR: 4.0; 95% CI: 1.3-13; p = 0.011), basilar artery bending <3 mm (OR: 3.4; 95% CI: 1.3-9.5; p = 0.0040), and pearl-and-string sign (OR: 5.7; 95% CI: 2.0-16; p = 0.0033). Conclusions: We suggest that the clinical and vertebrobasilar artery morphological characteristics demonstrated in the present study may be related to SAH induced by siVAD. Although all patients with siVAD should be closely monitored, those with siVAD who have these characteristics should perhaps be more closely followed than those who do not have such features.
    Cerebrovascular Diseases 11/2012; 34(5-6):393-399. · 3.70 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Intraventricular hemorrhage (IVH) is widely regarded as one element of a complex involving severe blunt traumatic brain injury (TBI); corpus callosum injury (CCI) is recently considered to be one factor associated with poor outcome in patients with TBI. Although postmortem studies have focused on the relationship between IVH and CCI, there have been few investigations of IVH evidenced on CT scans as a predictor of CCI evidenced on MRI. The authors retrospectively reviewed prospectively collected data from 371 patients with blunt TBI, without trauma to the face, chest, abdomen, extremities, or pelvic girdle, requiring immediate therapeutic intervention. Their aim was to investigate whether IVH found on CT predicts CCI on MRI. Clinical and radiological data were collected between June 2003 and February 2011. First, the authors classified patients into groups of those with CCI and those without CCI, and they compared clinical and radiological findings between them. Then, they investigated prognostic factors that were related to the development of disability at 6 months after injury. The outcomes at 6 months after injury were evaluated using the Extended Glasgow Outcome Scale (GOS-E). Finally, the authors evaluated the correlation between the severity of the IVH on CT and the number of CCI lesions on MRI. The severity of the IVH was defined by the number of ventricles in which IVH was seen, and the number of CCI lesions was counted on the MRI study. On multivariate logistic regression analysis, Glasgow Coma Scale score less than 9 (OR 2.70 [95% CI 1.10-6.27]), traffic accident (OR 2.59 [95% CI 1.37-4.93]), and IVH on CT (OR 3.31 [95% CI 1.25-8.49]) were significantly related to CCI. Multivariate analysis also showed that older age (p = 0.0001), male sex (OR 3.26 [95% CI 1.46-8.08], p = 0.0065), Glasgow Coma Scale score less than 9 (OR 8.27 [95% CI 3.39-21.4], p < 0.0001), evidence of IVH on CT (OR 4.09 [95% CI 1.45-11.9], p = 0.0081), and evidence of CCI on MRI (OR 8.32 [95% CI 3.89-18.8], p < 0.0001) were associated with future development of disability (GOS-E score ≤ 6). Furthermore, simple regression analysis revealed the existence of a strong correlation between the severity of IVH and the number of CCI lesions (r = 0.0668, p = 0.0022). The authors' results suggest that evidence of IVH on CT may indicate CCI, which can lead to disability in patients with isolated blunt TBI.
    Journal of Neurosurgery 06/2012; 117(2):334-9. · 3.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The relationship between body mass index (BMI) and stroke subtypes has received more research attention than that between BMI and location of intracerebral hemorrhage (ICH). Lobar hemorrhage (LH) differs from non-LH primarily in terms of etiology, i.e. cerebral amyloid angiopathy is the main cause of LH. This study aimed to determine the relationship between BMI and ICH. In this retrospective study involving 460 consecutive patients with ICH, BMI was significantly lower in LH than for other ICH locations. BMI categories were underweight (BMI < 18.5 kg/m(2)), normal weight (18.5-23.0 kg/m(2)), overweight (23.0-27.5 kg/m(2)), or obesity (≥27.5 kg/m(2)). Outcome at 1 year was evaluated by the modified Rankin Scale (mRS). We investigated the relationship of BMI and other clinical characteristics with LH and non-LH. LH was associated with age (>70 years), underweight, unfavorable outcome (mRS ≥3), and daily alcohol consumption. Hypertension and intraventricular bleeding were significantly less common in patients with LH than those with non-LH. Alongside risk factors conventionally thought to be related to LH, underweight may also be a LH-related factor, specifically in the elderly.
    Acta Neurologica Scandinavica 11/2011; 126(2):116-21. · 2.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Some studies have investigated the relationship between anatomic location and outcome in patients with cerebellar hemorrhage (CH), but not as yet the relationship between location of CH, as categorized according to vascular territory, and outcome. Furthermore, other studies have shown that taking antithrombotics was related to having CH; however, there have been no studies assessing the relationship between antithrombotics and the location of CH. The aim of this study was to determine whether the outcome of patients with CH at 1-year after onset differed depending on antithrombotic use and lesion location. A retrospective, single-institution study involving 53 patients with CH was conducted. Location of the CH, categorized by vascular territory, was classified as either superior cerebellar artery hemorrhage (SCAH), anterior inferior cerebellar artery hemorrhage, or posterior inferior cerebellar artery hemorrhage. Outcome was evaluated using the modified Rankin scale (mRS) and mRS was divided into good (mRS ≤2) or poor (mRS ≥3). Thirty-four patients had SCAH, 5 had anterior inferior cerebellar artery hemorrhage, and 14 had posterior inferior cerebellar artery hemorrhage. Patients with poor outcome had higher proportions of Glasgow coma scale score ≤8, SCAH, intraventricular bleeding, hydrocephalus, and maximal transverse diameter ≥30 mm by univariate analysis. After multivariate analysis, Glasgow coma scale score ≤8 and SCAH showed a significant association with poor outcome. Outcome at 1-year after onset differed by location of the CH lesion as categorized according to vascular territory. SCAH was related to poor outcome by a larger maximal transverse diameter of hematoma and hydrocephalus.
    World Neurosurgery 11/2011; 77(3-4):507-11. · 2.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Although there have been some reports regarding body mass index (BMI) and subtypes of stroke, there have been few concerning the relationship between BMI and location of spontaneous intracerebral hemorrhage (ICH). Determining the location of spontaneous ICH is important because outcome is thought to be affected by its location. The aim of this study was to determine whether location of spontaneous ICH varied according to BMI level. METHODS: In this retrospective study, 463 patients with spontaneous ICH were divided into 3 groups according to BMI (kg/m(2)): <18.5 (underweight), 18.5 to 24.0 (normal weight), 24.0 to 29 (overweight), and >29.0 (obesity). We compared the clinical characteristics among patients with putaminal, thalamic, lobar, pontine, or cerebellar hemorrhage on univariate and multinominal logistic regression analysis. RESULTS: Among the 5 locations, BMI level was lowest in patients with lobar hemorrhage and highest in those with pontine hemorrhage. Compared to patients with nonlobar hemorrhage, patients with lobar hemorrhage showed a higher proportion of individuals who were underweight, female, and age >70 years and a lower proportion who were hypertensive. Compared with patients with nonpontine hemorrhage, those with pontine hemorrhage showed a higher proportion of individuals who were obese. CONCLUSIONS: Our findings indicate that BMI can affect the location of spontaneous ICH.
    World Neurosurgery 11/2011; · 2.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies have shown a relationship between a patient's stage of diffuse axonal injury (DAI) and outcome. However, few studies have assessed whether a specific lesion or type of corpus callosum injury (CCI) influences outcome in patients with DAI. The authors investigated the effect of various DAIs and CCIs on outcome in patients with traumatic brain injury (TBI). The authors retrospectively reviewed 78 consecutive patients with DAI who were seen between May 2004 and March 2010. Outcome was evaluated using the Extended Glasgow Outcome Scale (EGOS) 1 year after TBI. Patients with single DAIs had only 1 of the 3 lesions (lobar, CC, or brainstem). Patients with dual DAIs had 2 of these lesions, and those with triple DAIs had all of these lesions. Furthermore, the authors defined single, dual, and triple CCIs by using 3 lesions (genu, body, splenium) in the same way among patients with single (CC) DAIs. Univariate and multivariate logistic regression analyses were performed to evaluate the relationships between these lesions and outcome in patients with DAI. Fifty patients had single DAIs: 34 in the lobar area, 11 in the CC, and 5 in the brainstem. Twenty had dual DAIs, and 8 had triple DAIs. Of the 11 CCIs, 9 were single and 2 were dual CCIs. Among these lesions, only those in the genu were related to disability. The authors dichotomized patients into those with and without genu lesions, regardless of other injuries. Multinomial logistic regression analysis showed that a genu lesion (OR 18, 95% CI 2.2-32; p = 0.0021) and a pupillary abnormality (OR 14, 95% CI 1.6-24; p = 0.0068) were associated with disability (EGOS ≤ 6) in patients with DAI. Regardless of the number of lesions, the existence of a genu lesion suggested disability 1 year after TBI in patients with DAI.
    Journal of Neurosurgery 07/2011; 115(5):1019-24. · 3.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Some reports have suggested that the location of primary intracerebral hemorrhage (ICH) is affected by oral antithrombotic agents (ATs). This is important, given the increasing use of ATs to treat arteriosclerotic disease. The aim of this study was to explore whether oral AT therapy increase the incidence of any specific location of primary ICH. A retrospective, single-institution study involving 410 Japanese patients with primary ICH was conducted between July 2003 and June 2009. Bivariate analyses (ie, Fisher's exact 2-tailed test, Student's t test, Welch's test, Wilcoxon's rank-sum test, Pearson's χ(2) test) and multivariate logistic regression analysis were performed for clinical characteristics of these patients. Of the 410 patients, 20% were taking ATs before the onset of primary ICH. The incidence of cerebellar hemorrhage (CH) exceeded that of other types of hemorrhage in patients taking ATs, and the difference was statistically significant on bivariate analysis (P < .0001). On multivariate analysis, only antiplatelet (AP) therapy was found to significantly increase the frequency of CH in patients with primary ICH (P = .0035). Our data indicate that taking APs before the onset of ICH a related factor for CH in Japanese patients with primary ICH.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 07/2011; 20(4):346-51. · 1.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies have shown a relationship between diffuse axonal injury (DAI) and unfavorable clinical outcome in patients with traumatic brain injury (TBI), but it remains unclear whether the type of DAI lesion influences outcome after TBI. The aim of the present study was to investigate whether 1-year outcome after TBI differed between patients with different types of lesions. A retrospective, single-institution study involving 261 patients with TBI was carried out between April 2003 and December 2009. Outcome was measured using the Glasgow Outcome Scale (GOS) 1 year after TBI. DAI lesions occurred in the lobar region, corpus callosum (CC), and brainstem. CC lesions were subdivided into three types: genu, body, and splenium. Univariate and multivariate logistic regression analyses were performed to evaluate the relationships between clinical characteristics and outcome for each type of DAI lesion and each type of CC lesion in patients with TBI. Sixty-nine patients had DAI lesions: 34 in the lobar region, 30 in the CC, and five in the brainstem. Of the 30 patients with CC lesions, ten each were found in the genu, body, and splenium. Each DAI, CC, and genu lesion was significantly associated with unfavorable outcome 1 year after TBI by multivariate analysis using variables that were significantly associated with unfavorable outcome as determined by univariate analysis after adjustment for age. CC lesions, especially those in the genu, were related to unfavorable 1-year outcome in patients with TBI.
    Acta Neurochirurgica 04/2011; 153(8):1687-93; discussion 1693-4. · 1.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: It is well known that spontaneous intradural vertebral artery dissection (siVAD) is an important cause of nontraumatic subarachnoid hemorrhage (SAH). The factors that influence whether SAH develops, however, remain unclear. The aim of this study was to investigate whether clinical characteristics and imaging findings are different in patients with siVAD with SAH compared to those with siVAD without SAH. The authors conducted a retrospective, single-institution study involving patients in whom siVAD developed with or without SAH, between July 2003 and November 2010. Univariate and multivariate analyses were performed to evaluate clinical characteristics and MR angiography findings. The vertebral-union-basilar angle (VUBA) was defined as the most acute angle between line of the basilar artery trunk and line of the vertebral angle (VA) at the vertebral union on 3D MR angiograms. Among 58 patients with siVAD, 21 developed SAH. The presence of siVAD and SAH was significantly associated with higher rates of current smoking (OR 13; 95% CI 3.6-38; p < 0.0001), dissection of the dominant VA (OR 9.2; 95% CI 2.5-19; p = 0.0004), and unruptured supratentorial nondissecting saccular aneurysms (OR 11; 95% CI 2.1-19; p = 0.0025), and the VUBA of the dominant VA was significantly larger (p < 0.0001, univariate analysis). Multivariate analysis showed that these differences were still significant (p < 0.05). A larger VUBA of the dominant VA, the presence of unruptured supratentorial nondissecting saccular aneurysms, and current smoking may be factors that predict which patients with siVAD will develop SAH by dominant VAD.
    Journal of Neurosurgery 03/2011; 115(1):108-12. · 3.15 Impact Factor