Publications by authors named "Hirokazu Bokura"

Background: Chronic kidney disease (CKD) has been closely associated with stroke. Although a large number of studies reported the relationship between CKD and different types of asymptomatic brain lesions, few comprehensive analyses have been performed for all types of silent brain lesions.

Methods: We performed a cross-sectional study involving 1,937 neurologically normal subjects (mean age 59.

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We report the case of a 64-year old man who presented memory disturbance, low-grade fever, weight loss, and bilateral hand tremors for three months. He was diagnosed with non-herpetic acute limbic encephalitis (NHALE). Follow-up magnetic resonance imaging (MRI) revealed new lesions after symptomatic improvement following steroid pulse therapy.

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Brain microbleeds (MBs) are represented as low-intensity spotty lesions on T2 *-weighted MR images and are frequently detected in healthy people and not only stroke patients. A recent meta-analysis revealed that MBs were present in 34% of patients with ischemic stroke and 60% with intracerebral hemorrhage, respectively. On the other hand, MBs only occur in approximately 4-6% of subjects without cerebrovascular disease and neurological symptoms.

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We describe a 76-year-old man with herpes encephalitis whose symptom of severe apathy was improved by the dopamine D2/D3 receptor agonist ropinirole. Brain magnetic resonance imaging had shown lesions in the patient's right mesial temporal cortex, right insula, and bilateral medial frontal regions. During treatment with acyclovir, he had developed severe apathy and depression.

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We present a case of cerebral embolism associated with a left atrial myxoma that was treated with intravenous thrombolytic therapy. A 79-year-old right-handed man with no history of neurological or psychiatric illnesses was referred to our hospital because of confusion. He had been self-supported in the activity of daily living and could enjoy gardening until just before his admission.

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This study aimed to examine the associations of cognitive function with hippocampal and whole brain atrophies, age, education, and diabetes-related parameters in patients with type 2 diabetes. Sixty-one patients over 65 years of age with type 2 diabetes and 53 age- and sex-matched non-diabetic controls were enrolled. Hippocampal and whole brain atrophies were assessed by quantifying hippocampal and brain volumes by brain magnetic resonance imaging.

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Background And Purpose: Cerebral microbleeds (MBs) are frequently detected in patients with stroke, especially those who experience intracerebral hemorrhage. However, the clinical significance of MBs in subjects without cerebrovascular disease is still unclear. We performed a prospective study to determine whether the presence of MBs provides useful prognostic information in healthy elderly individuals.

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Background/aims: The aim of this study is to examine whether metabolic syndrome is directly associated with cognitive impairment independent of subclinical ischemic brain lesions.

Methods: We examined 1,543 neurologically normal subjects (44-86 years of age). Metabolic syndrome, brain MRI, and cognitive functions including general cognition and executive function were assessed.

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Background: Although apathy has been reported as one of the neuropsychiatric symptoms following stroke, there are few studies on regional cerebral blood flow (rCBF) in stroke patients with apathy. The present study compared rCBF between apathetic and non-apathetic patients after stroke.

Methods: We recruited 102 patients with cerebral infarction within 1 month after stroke and performed neuropsychiatric assessments that included the apathy scale.

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Although cumulative evidence indicates that risk factors for arteriosclerosis have an impact on age-related changes in brain pathology, the influence of aging without major risk factors on changes in brain structures has not yet been fully elucidated. We used magnetic resonance imaging (MRI) to study how aging affects structural changes in the brain (eg, white matter lesions, hippocampal atrophy [HA], microbleeds) in normal subjects without major risk factors for cerebrovascular diseases. We studied 1108 subjects who underwent voluntary brain screening and had no cerebrovascular risk factors, such as hypertension, diabetes mellitus, or hyperlipidemia.

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Dopamine D2/3 receptor agonists have been widely used to treat motor symptoms in Parkinson's disease and are also reported to improve cognitive and emotional disturbances. Here we describe a patient who developed severe apathy after cerebral infarction in the prefrontal cortex. After administration of ropinirole, his verbal output and spontaneity in daily life was improved remarkably.

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Aim: To evaluate the efficacy, outcome, and side effects of tissue plasminogen activator for cerebral infarction in patients aged 75 years or older.

Methods: Subjects consisted of 30 patients who had been treated with tissue plasminogen activator between October, 2005 and March 2009, in Shimane University Hospital. We divided the patients into two groups: those less than 75 years old and those 75 years old and older, and evaluated the pattern of disease, therapeutic efficacy, side effects of bleeding, and factors affecting the modified Rankin Scale on discharge.

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Background: Microangiopathy-related cerebral damage (MARCD) is an entity of cerebrovascular disease based on arteriosclerosis in deep white matter, which includes lacunar infarction and white matter hyperintensity (WMH). As asymmetric dimethylarginine (ADMA), an endogenous inhibitor of the nitric oxide (NO) synthases, and homocysteine are both potential risk factors for arteriosclerosis, the plasma levels of these two substances were evaluated in individuals with MARCD.

Methods: Consecutive participants of a health examination (401 males and 311 females) were recruited for this cross-sectional study.

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A 50-year-old woman presented with confusion, fever and drowsiness following an episode of headache and dizziness. On admission, neurological examination found positive pyramidal tract signs, meningeal irritation, and bilateral myoclonus in her arms. Laboratory tests revealed liver dysfunction, positive inflammatory reaction, elevated serum IgM antibody against cytomegalovirus, and increased cerebrospinal fluid protein of 67 mg/dl.

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Aim: We studied the influences of silent brain infarction (SBI) and hypertension on brain atrophy and its longitudinal progression in healthy adults.

Methods: MRI scans were performed on 109 neurologically normal adults (mean age, 58.6+/-5.

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Background And Purpose: Metabolic syndrome (MetS) is a recognized risk factor for stroke, but it is unclear whether MetS is also related to subclinical ischemic lesions. We examined the association of MetS with the prevalence of silent brain infarction, periventricular hyperintensity, and subcortical white matter lesions in healthy adults.

Methods: We conducted a cross-sectional study in 1151 Japanese healthy subjects.

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Response inhibition is one of the highest evolved executive functions of human beings. Previous studies revealed a wide variety of brain regions related to response inhibition, although some of them may not be directly related to inhibition but to task-specific effects or noninhibitory cognitive functions such as attention, response competition, or error detection. Here, we conducted event-related functional magnetic resonance imaging studies in which all subjects performed both stop-signal and go/no-go tasks in order to explore key neural correlates within the response inhibition network irrelevant to task designs and other cognitive processes.

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Silent brain infarction (SBI) and white matter lesions (periventricular hyperintensity [PVH] and subcortical white matter lesions [SWML] are detected in both stroke patients and normal elderly persons. We prospectively examined the association between these lesions and the risk of subsequent stroke and mortality in neurologically normal adults. Magnetic resonance imaging scans were performed in 2,684 neurologically normal subjects with no history of stroke (mean age, 58 +/- 7 years old at entry) who underwent our health screening of the brain.

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We evaluated the efficacy of intravenous (IV) urokinase (UK) treatment for acute ischemic stroke patients. We treated 45 patients with 0.42 mega units of IV UK and 201 patients with other conventional agents.

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Background: Metabolic syndrome is a characterized by a cluster of cardiovascular risk factors, including visceral obesity, insulin resistance, dyslipidemia, and hypertension. The criteria for diagnosing metabolic syndrome differ among ethnic groups, due in part to differences in eating habits and body build. Little is known about the relationship between metabolic syndrome and ischemic stroke in Asian countries.

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Background: The frontal assessment battery (FAB) test is a composite tool for assessing executive functions related to the frontal lobe. Neuropsychological and blood-flow studies indicate distinct patterns of deterioration of anterior and posterior cortical function in Alzheimer's disease (AD) and subcortical vascular dementia (VD) patients. We predict that the FAB score may be useful for discriminating VD from AD.

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We studied clinical characteristics and prognosis in acute stoke patients with diabetes mellitus registered on the Japanese Standard Stroke Registry database. A total of 16,630 acute stroke patients admitted to 56 hospitals in Japan. They were examined as to their stroke types, risk factors, their severity of stroke according to the NIH Stroke Scale (NIHSS) and Japan Stroke Scale (JSS), and outcomes by the modified Rankin Scale (m-RS).

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We report augmentation of somatosensory evoked potentials (SEP) in a patient with frontal alien hand signs after left medial frontal lobe damage. The SEP components occurring later than 30 msec post stimuli were enhanced over the parietal and frontal scalp sites of the lesioned hemisphere. This finding suggests that deficits in inhibitory control of somatosensory processing in parietal and frontal lobes contributes in some way to frontal alien hand signs.

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Thrombolytic therapy for ischemic stroke has not been approved in Japan yet. However, we have used intravenous t-PA for acute ischemic stroke patients. We reviewed the clinical data on patients who were treated with intravenous t-PA and entered in the stroke registry of our hospital between April 1999 and March 2004.

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