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Biomedical subjects

Y Tazaki

Publications and source records attributed to Y Tazaki.

At least 19 recordsLinked to original sources
PubMed1992

[Neurological and neuroimaging studies of eclampsia].

Clinical and neuroimaging studies were made in twenty-one patients during the attack of eclampsia. Most frequent neurological signs and symptoms were the impairment of consciousness, headache, seizure and visual disturbance. Mean arterial blood pressure increased by 46 mmHg (n = 21) during the attacks. Eight of 9 patients studied by CT and/or MRI showed transient abnormalities on brain images during the attack in the occipital cortex, basal ganglia, and internal and external capsule. The findings were compatible with brain edema and were seen mainly in the white matter. Cerebral blood flow measured by SPECT method in one patient during an attack with visual disturbance showed increased blood flow in the occipital cortex. Acute increase in blood pressure, cerebral hyperperfusion and edema, similar to the pathophysiology of hypertensive encephalopathy, were considered to play an important role in the pathogenesis of eclampsia.

Adult↗
PubMed1991

Magnetic resonance imaging of the brain in patients with migraine.

Magnetic resonance imaging (MRI) was studied in 91 patients with migraine and in 98 controls. Risk factors known to cause MRI lesions were carefully examined. In 36 patients with migraine (39.6%), small foci of high intensity on T2-weighted and proton-density-weighted images were seen in the white matter. Of patients with migraine who were less than 40 years old and without any risk factor, 29.4% showed lesions on MRI; this was significantly higher than the 11.2% for the group of age-matched controls (n = 98). The lesions were distributed predominantly in the centrum semiovale and frontal white matter in young patients, but extended to the deeper white matter at the level of basal ganglia in the older age group. The side of the MRI lesions did not always correspond to the side of usual aura or headache. Migraine-related variables such as type of migraine, frequency, duration or intensity of headache or consumption of ergotamine showed no significant correlation with the incidence of MRI abnormalities. Our data indicated that migraine may be associated with early pathologic changes in the brain.

Adult↗
PubMed1991

Increase in cerebrospinal fluid and plasma levels of 3-methoxy-4-hydroxyphenylglycol in acute stroke.

BACKGROUND AND PURPOSE: 3-Methoxy-4-hydroxyphenylglycol is known to be a principal metabolite of brain norepinephrine and to be released into the blood and cerebrospinal fluid in association with activation of the central noradrenergic system. We examined changes in plasma and cerebrospinal fluid levels of 3-methoxy-4-hydroxyphenylglycol during acute stroke to see if there might be a correlation between these and the patient's clinical state. METHODS: We measured plasma levels of 3-methoxy-4-hydroxyphenylglycol in 32 control subjects and in 50 patients with brain hemorrhage and 57 patients with brain infarction who were admitted to the hospital within 72 hours after onset. In addition, we estimated 3-methoxy-4-hydroxyphenylglycol concentrations in the cerebrospinal fluid of 37 patients with brain infarction and eight control patients. RESULTS: Mean +/- SEM values for plasma 3-methoxy-4-hydroxyphenylglycol in the patients with brain hemorrhage and those with brain infarction were 7.3 +/- 0.5 and 6.6 +/- 0.5 ng/ml, respectively. Both values were significantly higher than that obtained in the 32 control subjects (4.6 +/- 0.3 ng/ml, p less than 0.01). Plasma levels of 3-methoxy-4-hydroxyphenylglycol correlated well with state of consciousness and prognosis. The mean +/- SEM level of 3-methoxy-4-hydroxyphenylglycol in the cerebrospinal fluid of the 37 patients with brain infarction (10.9 +/- 0.6 ng/ml) was also significantly higher than that in the eight control patients (7.9 +/- 0.6 ng/ml, p less than 0.01). CONCLUSIONS: The observed increase in plasma and cerebrospinal fluid levels of 3-methoxy-4-hydroxyphenylglycol implies that the activity of the central noradrenergic neurons may be enhanced at the onset of stroke, and these levels may be related to some extent to the clinical state and prognosis of stroke patients.

Aged↗
PubMed1991

[Pathogenesis of ipsilateral hemiparesis in patients with lateral medullary syndrome].

Lateral medullary syndrome is known to cause hemiparesis ipsilateral to the medullary lesion. However, it's clinical significance has not been fully evaluated. In this study, we made clinical and angiographic studies in patients with syndrome to elucidate the pathogenesis of ipsilateral hemiparesis. Thirty-four patients with cerebral infarction presenting with this syndrome were studied. Their mean age was 51 years and all the patients were examined within 6 months of their first attack. Diagnosis of ipsilateral hemiparesis was made if subjective feeling of weakness in the upper and lower extremities was associated with increased deep tendon reflexes. Ipsilateral hemiparesis was observed in 38% of all the patients. Cerebral angiography was performed in 26 patients and divided into two groups; group A with ipsilateral hemiparesis (n = 9) and group B without ipsilateral hemiparesis (n = 7). In 56% of patients in group A, angiography showed non-visualization of ipsilateral vertebral artery (VA) and posterior inferior cerebellar artery (PICA). Non-visualization of these two arteries never occurred in the patients of group B. On the other hand, non-visualization of VA alone was observed in 35% of the patients in group B, but it was none in the patients of group A. However, there were no differences in concerning the frequency of non-visualization of PICA alone or non-occlusion at all between both groups. Therefore, the focal ischemia in the region below the pyramidal decussation due to the occlusion of both VA and PICA, regardless of thrombotic or embolic episode, was considered to be responsible for ipsilateral hemiparesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Clinical aspects of brainstem infarction].

Ischemic stroke in the vertebrobasilar arterial territory often presents stunning signs and symptoms, and poses little difficulty in the clinical diagnosis. But in less dramatic cases, it is often difficult to make accurate clinical diagnosis and to document the precise extent of an infarct. The purpose of the present study is to demonstrate clinicotopographic correlations in patients with various brainstem and cerebellar infarctions and to reevaluate the importance of bedside clinical examinations for understanding pathophysiology and planning management of the patient. One hundred forty-three patients with clinical diagnosis of the vertebrobasilar infarction confirmed by MRI were studied. MRI is superior to CT scanning in delineating areas of infarction in the territory of posterior cerebral circulation because of the three dimensional approach and the lack of bone artifact. MRI also allowed very precise clinicotopographic correlations even in patients with good recovery, in whom pathologic verification of the lesion is not possible. There are some restrictions of MRI diagnosis to detect the clinical features which change from hour to hour, because of the mechanical limitation in spatial resolution and of the temporal uncertainty of the lesions such as reversible edema or coincidental asymptomatic old lesions. Clinical importance of ocular signs (eg. skew deviation, gaze limitations, nystagmus, pupillary abnormalities and so on) was discussed. Some eye-movement abnormalities (eg. gaze paresis, MLF syndrome, 'one-and-a-half' syndrome, lateropulsion or contrapulsion of eyes, and vertical nystagmus at the primary position) served as useful localizing signs, and especially their consecutive observations were of importance for clinical local diagnosis. Clinical syndromes, caused by lacunar lesions located either in the supratentorial or in the infratentorial structures, such as pure motor hemiparesis and ataxic hemiparesis were also discussed. In some cases of these syndromes, MRI failed to document the precise lesion responsible for the episode due to the multiplicities of small asymptomatic lesions. Even in such cases, detailed clinical informations (temporal profiles of the episode, past medical histories, neuro-ophthalmic signs and so on) may enable the differential diagnosis. It is concluded that the use of new imaging techniques such as MRI may provide new insights in the diagnosis of cerebrovascular diseases, but the importance of clinical observations can not be overemphasized.

Adult↗
PubMed1989

Cerebral blood flow and cerebral hematocrit in patients with cerebral ischemia measured by single-photon emission computed tomography.

Single-photon emission computed tomography (SPECT) was used for the measurement of regional cerebral blood flow (CBF), cerebral blood volume (CBV) and cerebral hematocrit (Hct). CBF was measured using N-isopropyl-p-I-123-Iodoamphetamine. CBV was measured by both RBC tracer (Tc-99m RBC) and plasma tracer (Tc-99m human serum albumin) and cerebral hematocrit (Hct) was calculated. In normals, the cerebral-to-large vessel Hct ratio was 75.9%. Isovolemic hemodilution in patients with high Hct tended to increase the cerebral-to-large vessel Hct ratio. Low CBF, high CBV and slow cerebral blood mean transit time (MTT by dynamic CT scanning) was seen during the acute stage of completed infarction and during the symptom-free interval of TIA. Cerebral Hct was increased in the ischemic region of poor prognosis.

Adult↗
PubMed1989

[Isolated angitis of the central nervous system--case report and review].

Isolated angitis of the central nervous system (IACNS) is rare condition with inflammation limited to vessels supplying the brain. This IACNS has been a poorly characterized and infrequently reported illness since it was first described as a separate entity in 1959. However, a patient with IACNS has not been reported in Japan. A patient, 39-year old-male, with IACNS limited to small and middle vessels is described. Recurrent, transient consciousness disturbances, focal myoclonus, papilloedema and temporal lobe epilepsy were observed during disease course. CSF finding of this patient showed lymphocytosis with marked increased protein. Carotid and vertebral angiogram showed irregular luminal outline in branches of all arteries. The most specific finding is that of alternating areas of focal stenosis and ectasia giving a "sausage" pattern. These characteristic findings showed in the branch of external carotid arteries. There was no evidence of systemic vasculitis by systemic angiography. Biopsy of temporal artery showed lymphocyte infiltration, fibrinoid necrosis without giant cell and granuloma. Formation of A-V malformation in the branch of external carotid artery was also observed. This histopathological finding was compatible with necrotizing angitis, not granulomatous angitis. Isolated angitis of the central nervous system was diagnosed. In spite of his administration of corticosteroid, cerebrospinal fluid abnormalities has not responded markedly. Abnormal findings of carotid and vertebral angiogram also has not changed. After 7 years from his onset, his neurologic signs and symptoms were well controlled with administration of anti-epileptic drugs.

Adult↗
PubMed1988

Regional cerebral blood flow during an attack of vertebrobasilar insufficiency.

Using technetium-99m-labeled hexamethylpropyleneamineoxime [( 99mTc]HM-PAO) and single-photon emission computed tomography, we measured changes in regional cerebral blood flow in a 58-year-old man during an attack of vertebrobasilar insufficiency. Angiography demonstrated compression of the left vertebral artery by the osteophytes of cervical spondylosis when the patient turned his head to the left. Measured in the orthostatic position while turning his head to the left during a typical attack of vertebrobasilar insufficiency, regional cerebral blood flow was significantly reduced in the left cerebellum and the right occipital region. Our study illustrates the capability of [99mTc]HM-PAO single-photon emission computed tomography to measure transient reductions in regional cerebral blood flow and to relate these changes to the pathophysiology of vertebrobasilar insufficiency.

Cerebral Angiography↗
PubMed1988

Treatment of acute cerebral infarction with a choline precursor in a multicenter double-blind placebo-controlled study.

A multicenter double-blind placebo-controlled study of cytidine 5'-diphosphocholine (CDP-choline) was conducted to evaluate possible clinical benefits of the drug in patients with acute, moderate to severe cerebral infarction. The patients included also suffered from moderate to mild disturbances of consciousness, and all were admitted within 14 days of the ictus. Patients were allocated randomly to treatment with either CDP-choline (1,000 mg/day i.v. once daily for 14 days) or with placebo (physiological saline). One hundred thirty-three patients received CDP-choline treatment, and 139 received placebo. The group treated with CDP-choline showed significant improvements in level of consciousness compared with the placebo-treated group, and CDP-choline was an entirely safe treatment.

Acute Disease↗
PubMed1986

Primary leptomeningeal ependymoblastoma. Case report.

Ependymoblastoma is considered to be a primitive malignant glioma with ependymal differentiation. This rare tumor occurs in very early life and shows rapid growth and a diffuse infiltration through the leptomeningeal space. The tumor cells are highly immature, with numerous mitoses and multilayered ependymal rosettes. The ependymoblastoma described in this report was found in a 17-year-old girl. In spite of detailed clinical and postmortem examinations, no definite primary site was identified in the neuraxis. The lesion spread predominantly throughout the leptomeningeal space. Histological analysis strongly suggested that this tumor originated from a heterotopic glial nest in the subarachnoid space. The absence of immunohistochemical neural tissue markers, glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, and neurofilaments ruled out neuronal or glial differentiation. The authors were unable to find any previous report of primary leptomeningeal ependymoblastoma.

Adolescent↗