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Biomedical subjects

N Kuwana

Publications and source records attributed to N Kuwana.

At least 19 recordsLinked to original sources
PubMed2001

Spinal leptomeningeal metastases of giant cell glioblastoma associated with subarachnoid haemorrhage: case report.

A case of subarachnoid haemorrhage (SAH) due to spinal leptomeningeal metastases of a giant cell glioblastoma is described. A 51 year old male presented with a four week history of headache. Neurological examination was normal except for a slight left hemiparesis. Computed tomography (CT) revealed a large cyst with a mural nodule in the right temporal lobe. The tumour was removed followed by 60 Gy of radiation therapy. Thirty-two months later he developed headache and shoulder pain with symptoms of normal pressure hydrocephalus. Head CT showed ventriculomegaly and SAH. Magnetic resonance imaging showed spinal leptomeningeal metastases at the C4-5, T12, and L2 levels, but no local recurrence or tumour dissemination in the brain. He died 34 months after surgery. Autopsy revealed diffuse SAH over the whole brain and spinal cord, associated with spinal leptomeningeal metastases, but no cerebral aneurysms. Spinal radiotherapy and ventriculoperitoneal shunting could possibly have extended survival in this patient.

Brain Neoplasms↗
PubMed2001

Cerebrovascular reactivity to acetazolamide in alert patients with cerebral infarction: usefulness of first-pass radionuclide angiography using 99m Tc-HMPAO in monitoring cerebral haemodynamics.

Cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) were studied in 75 patients with cerebral infarction. All patients were alert with the symptoms of hemiparesis and/or aphasia, and were divided into two groups: 42 patients had occlusion or stenosis of >75% at the internal carotid artery or main trunk of middle cerebral artery; and 33 patients did not. Hemispheric mean CBF was measured by performing first-pass radionuclide angiography using 99mTc-hexamethylpropylene amine oxime. CVR was measured as the percentage change from the baseline mean CBF value after the administration of 500 mg acetazolamide. The CVR in both groups was significantly impaired (5.2+/-6.3%, P<0.001 and 7.7+/-6.1%, P<0.01, respectively) compared with normal controls (14.7+/-3.3%), although the mean CBF was not significantly reduced compared with age-matched controls. In the 12 patients with unilateral carotid occlusion, five patients with good collateral flow via the anterior communicating artery showed preserved CVR (11.0+/-7.8%), but those without did not (1.6+/-7.0%). CVR is impaired in alert patients with cerebral infarction, although the mean CBF is not reduced, and good collateral flow via the anterior communicating artery in patients with carotid occlusion may be a sign of well-preserved haemodynamic status.

Acetazolamide↗
PubMed2000

Impairment of cerebrovascular reactivity to acetazolamide in patients with normal pressure hydrocephalus.

Cerebrovascular reactivity (CVR) to acetazolamide was investigated in 41 patients with normal pressure hydrocephalus (NPH). The aetiology was subarachnoid haemorrhage in 20 patients, trauma in nine, brain tumour in three and idiopathic in nine. Mean cerebral blood flow (CBF) of the whole brain was measured by performing first-pass radionuclide angiography using 99Tcm-hexamethylpropylene++ amine oxime. Cerebrovascular reactivity was measured as the percentage change from the baseline mean CBF value after the administration of 500 mg of acetazolamide. Cerebrovascular reactivity was significantly (P < 0.001) reduced in patients with the complete triad of NPH (1.4 +/- 3.1%), regardless of the aetiology, compared with normal controls (14.7 +/- 3.3%). Patients with the incomplete triad also showed significantly (P < 0.05) reduced CVR (9.6 +/- 5.4%). Patients with the complete triad had significantly (P < 0.001) lower CVR than those with the incomplete triad. Post-operative CVR in both groups (20 patients with the complete triad and 9 patients with the incomplete triad) increased significantly, from 1.5 +/- 3.5% to 10.0 +/- 5.5% (P < 0.001) and from 8.7 +/- 4.9% to 14.9 +/- 5.4% (P < 0.05), respectively. Cerebrovascular reactivity is impaired in patients with NPH regardless of the aetiology and improves after shunting.

Acetazolamide↗
PubMed1999

Management of patients with normal-pressure hydrocephalus by using lumboperitoneal shunt system with the Codman Hakim programmable valve.

Thirty-two patients with normal-pressure hydrocephalus were managed using the lumboperitoneal (LP) shunt system in which the Codman Hakim programmable valve was utilized. The initial opening pressure was set at 100 mm H(2)O in three cases, 80 mm H(2)O in two, 70 mm H(2)O in three cases, 50 mm H(2)O in 23, and 30 mm H(2)O in one case (mean pressure 57.8 mm H(2)O). In 12 patients the valve pressure required reprogramming. The final valve pressure was 30 mm H(2)O in four cases, 50 mm H(2)O in 19, 70 mm H(2)O in three, 80 mm H(2)O in one, 100 mm H(2)O in two, 130 mm H(2)O in one, 140 mm H(2)O in one, and 170 mm H(2)O in one case (mean 62.5 mm H(2)O). Lumboperitoneal shuntography was performed in five patients by injection of contrast medium into the prechamber. In two patients a shunt obstruction developed between the valve and the lumbar catheter. Complications occurred in eight patients. Low-pressure symptoms such as headache and vomiting were observed in four patients but disappeared after increasing the valve pressure. One patient, whose shunt pressure was set at 50 mm H(2)O developed a slight asymptomatic subdural effusion, which resolved after increasing the valve pressure to 100 mm H(2)O. Convulsions developed in two aged patients but were easily controlled with anticonvulsant medication. Surgery-related wound infection was observed in one patient. The major advantage in the use of this valve is the ability to modify the pressure noninvasively. Another important advantage of the LP shunt system in which this valve is incorporated is the lower pressure of 30 mm H(2)O that can improve symptoms caused by underdrainage of cerebrospinal fluid.

Journal Article↗
PubMed1999

Response of cerebral blood flow and cerebrovascular reactivity to acetazolamide in patients with dementia and idiopathic normal-pressure hydrocephalus.

The responses of cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to administration of acetazolamide were investigated in 16 patients with dementia and ventriculomegaly to clarify the cerebral hemodynamics in patients with idiopathic normal-pressure hydrocephalus (NPH). The mean CBF velocity in the whole brain was measured by the Patlak plot method by using technetium-99m hexamethylpropyleneamine oxime single-photon emission computerized tomography. The CVR values were obtained from the response to administration of 500 mg of acetazolamide and calculated as the percentage of change from the baseline mean CBF value. The mean CBF value was significantly reduced (p < 0.01) in six patients with (35.2 +/- 5 ml/100 g/minute) and 10 patients without (33.5 +/- 2.8 ml/100 g/minute) NPH compared with the age-matched normal controls (40.8 +/- 3.2 ml/100 g/minute), showing no significant difference. The CVR was significantly impaired in patients with NPH (0.8 +/- 1.7%; p < 0.001), whereas in patients without NPH preserved CVR (11.3 +/- 3%) was demonstrated compared with the normal controls (14.7 +/- 1.1%). In patients with NPH a significantly lower CVR (p < 0.001) was shown than in those without NPH. The CVR significantly increased (p < 0.001) after placement of a shunt in patients with NPH. Reductions in both CBF and CVR may be diagnostic indicators of NPH in patients with dementia in whom ventriculomegaly is present. In patients with dementia and idiopathic NPH both reduced CBF and extremely impaired CVR are shown. The results of the present study suggest that ischemia due to the process of NPH is responsible for the reduction of CBF and manifestation of symptoms in patients with idiopathic NPH.

Journal Article↗
PubMed1999

Effects of peritumoural oedema on cerebral blood flow and cerebrovascular reactivity in patients with alert consciousness.

The effects of peritumoural oedema on cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) were studied in 18 patients with alert consciousness. Hemispheric mean CBF was measured by performing first-pass radionuclide angiography using technetium-99m hexamethylpropylene amine oxime. CVR was measured as the percentage change from the baseline mean CBF value after acetazolamide administration. Patients were classified into three groups according to the severity of peritumoural oedema. The mean CBF of both hemispheres in each group was not significantly different from that of age-matched controls. CVR was preserved in patients with mild peritumoural oedema (n=6), but was significantly (P<0.01) reduced in patients with moderate (n=7) and severe peritumoural oedema (n=5). No significant correlation was found between the degree of midline shift and the mean CVR of both hemispheres (P=0.09). Surgical removal of the tumour significantly (P<0.05) improved the impaired CVR, although the mean CBF did not change. Administration of glucocorticoid improved the impaired CVR, without a change in the mean CBF, in a patient with a metastatic brain tumour. We conclude that CVR is impaired by the development of peritumoural oedema prior to changes in mean CBF.

Acetazolamide↗
PubMed1999

Epithelioid hemangioma of the temporal artery clinically mimicking temporal arteritis.

A rare case of epithelioid hemangioma (angiolymphoid hyperplasia with eosinophilia) arising in the right temporal artery of a 68-year-old Japanese woman was investigated. The patient had been treated with corticosteroids (Predonine 5 mg/day p.o.) for 4 years for idiopathic thrombocytopenic purpura. Headaches in the right temporal region with repeated high fevers first appeared 1 year prior to the biopsy of a nodule at the artery. The clinical diagnosis was temporal arteritis (giant cell arteritis). The specimen consisted of a short segment of the superior arterial branch having a sheet-like proliferation of the epithelioid endothelial cells in the lumen, which was almost occluded, focal rupture of the media, and marked proliferation of the capillaries (neovascularization) radiating out from the media to the adventitia. There were scattered foci of inflammatory cell infiltration composed mainly of small lymphocytes in the adventitia, but there were no histological changes suggestive of giant cell arteritis. The lesion was thus characterized by the proliferation of epithelioid endothelial cells in the lumen of the artery, and neovascularization between the media and adventitia. The histological features were very close to epithelioid hemangioma except for the absence of an eosinophilic reaction. The long-term administration of corticosteroids may have suppressed it. The authors believe this is the first case of epithelioid hemangioma arising from the temporal artery without a history of trauma. It showed some unique features both clinically and histopathologically, which contributed to the study of the yet not clearly classified vascular proliferative lesion, epithelioid hemangioma.

Aged↗
PubMed1999

Cerebral blood flow in patients with normal pressure hydrocephalus.

Mean cerebral blood flow (CBF) of the whole brain was measured in 48 patients who underwent cerebrospinal fluid shunt surgery for normal pressure hydrocephalus (NPH) by performing first-pass radionuclide angiography using 99Tcm-hexamethylpropylene amine oxime. Patients were divided according to outcome into an 'excellent' improvement group, a 'good' improvement group, a 'fair' improvement group and a 'poor' improvement group. Patients with excellent and good improvement had a preoperative mean CBF of 40.4 +/- 3.9 ml.100 g-1.min-1 and 37.1 +/- 5.5 ml.100 g-1.min-1, respectively, both of which were significantly (P < 0.005) higher than that in 11 patients who showed fair improvement (30.8 +/- 3.2 ml.100 g-1.min-1) and six patients who showed poor improvement (31.8 +/- 2.5 ml.100 g-1.min-1). Patients with a clinical improvement after shunting had an increased postoperative mean CBF. We conclude that patients with a preoperative mean CBF of over 35 ml.100 g-1.min-1 can show favourable improvement after a shunting procedure, and that the preoperative mean CBF of 32 ml.100 g-1.min-1 can be considered the critical level for treatment.

Adult↗
PubMed1999

Prediction of effectiveness of shunting in patients with normal pressure hydrocephalus by cerebral blood flow measurement and computed tomography cisternography.

Measurement of cerebral blood flow (CBF) and computed tomography (CT) cisternography were performed in 37 patients with a tentative diagnosis of normal pressure hydrocephalus (NPH) to predict their surgical outcome. The mean CBF of the whole brain was measured quantitatively by single photon emission computed tomography with technetium-99m-hexamethylpropylene amine oxime before surgery. The results of CT cisternography were classified into four patterns: type I, no ventricular stasis at 24 hours; type II, no ventricular stasis with delayed clearance of cerebral blush; type III, persistent ventricular stasis with prominent cerebral blush; type IV, persistent ventricular stasis with diminished cerebral blush and/or asymmetrical filling of the sylvian fissures. The mean CBF was significantly lower than that of age-matched controls (p < 0.005). Patients with a favorable outcome had a significantly higher mean CBF than patients with an unfavorable outcome (p < 0.005). Patients with the type I pattern did not respond to shunting. Some patients with type II and III patterns responded to shunting but improvement was unsatisfactory. Patients with type IV pattern responded well to shunting, and those with a mean CBF of 35 ml/100 g/min or over achieved a favorable outcome. The combination of CBF measurement and CT cisternography can improve the prediction of surgical outcome in patients with suspected NPH.

Adult↗
PubMed1998

Cerebral blood flow measurement in patients with impaired consciousness: usefulness of 99mTc-HMPAO single-photon emission tomography in clinical practice.

The relationship between impairment of consciousness and quantitative cerebral blood flow (CBF) was investigated. The mean CBF of the whole brain was measured by the Patlak-plot method using technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (99mTc-HMPAO SPET) in patients with the following diseases: cerebral infarction, intraparenchymal haemorrhage, subarachnoid haemorrhage, brain tumour and cerebral contusion. The clinical symptoms were evaluated according to the severity of impaired consciousness, aphasia and dementia. Four hundred and eighty-five CBF measurements were performed. Patients with alert consciousness showed an age-related decline in mean CBF. Patients with aphasia showed a significant reduction in mean CBF compared with those without aphasia. Impaired consciousness was proportional to reduction in mean CBF regardless of types of pathology, and the size of lesion did not influence the mean CBF. Patients with dementia showed a significant reduction in mean CBF proportional to the severity of dementia. The quantitative measurement of CBF using 99mTc-HMPAO SPET is reliable in clinical evaluations.

Adolescent↗
PubMed1995

Dopamine responsiveness of human prolactinoma cells as determined by the reverse hemolytic plaque assay.

The responsiveness in vivo to dopamine of prolactin (PRL) secretion in patients with prolactinoma was compared with that in vitro of single cells obtained from the same prolactinomas by surgical operations. Six patients with prolactinoma showing various degrees of hyperprolactinemia were challenged by bromocriptine suppression test (2.5 mg, peroral) before operation. Bromocriptine administration caused a decrease in the serum PRL concentration ranging 24-95% and there was no correlation between the basal PRL level and bromocriptine-induced inhibition. Monodispersed pituitary cells obtained from the prolactinomas by operation were subjected to a reverse hemolytic plaque assay for PRL to determine PRL secretion at the single cell level under basal conditions as well as in response to dopamine. The percentage of plaque-forming cells under basal conditions ranged 15-55% among the prolactinomas. The percentage of plaque-forming cells and plaque area were decreased in a dose-dependent manner by 10(-7) - 10(-5) M dopamine for the pituitary cells obtained from some adenomas but not for those from other adenomas. When the inhibition rates in vitro due to 10(-5) M dopamine in these two parameters were compared with the inhibition rate in vivo in the serum PRL concentration due to bromocriptine, it was found that there was a significant correlation between them. These results show that the reverse hemolytic plaque assay can be used to determine in vitro responsiveness to dopamine of PRL secretion from single prolactinoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Mammosomatotroph adenoma cells secrete both growth hormone and prolactin.

Pituitary adenoma cells from a mammosomatotroph adenoma obtained from a 21-year-old female presenting with acromegaly and amenorrhea were investigated by sandwich cell immunoblot assay, immunohistochemistry, and electron microscopy. The new, simple technique of sandwich cell immunoblot assay could detect two hormones secreted in the same one cell, and found that 89% of mammosomatotrophs secreted both growth hormone (GH) and prolactin (PRL). Immunohistochemistry showed that the tumor cells were positive for both GH and PRL. Electron microscopy showed cells contained granules ranging in size form 150 to 500 nm. This is the first demonstration of both GH and PRL in the same mammosomatotroph cell. Sandwich cell immunoblot assay can measure the amount of secreted hormone, allowing a new approach to the investigation of mammosomatotroph adenomas.

Adenoma↗
PubMed1994

Differentiation of malignant glioma and metastatic brain tumor by thallium-201 single photon emission computed tomography.

The use of superdelayed thallium-201 single photon emission computed tomography (201Tl SPECT) for differentiating malignant gliomas from cerebral metastases was investigated in 23 patients (7 with meningioma, 6 with glioma, 7 with cerebral metastasis, 1 with each of neurinoma, abscess, and necrosis). 4 mCi of 201Tl was injected intravenously, and gamma camera scans were performed after 10 minutes and 4, 24, 72, and 96 hours (superdelayed scan). The mean thallium index of meningiomas was significantly higher than those of gliomas and cerebral metastases after 10 minutes, while the mean thallium indices of meningiomas and gliomas were significantly higher than those of cerebral metastases after 96 hours. The combination of early and superdelayed 201Tl SPECT may be useful in differentiating malignant gliomas from cerebral metastases.

Aged↗
PubMed1993

Progressive diffuse arteriovenous malformation--case report.

A rare diffuse arteriovenous malformation (AVM) occurred in an 11-year-old boy with a 4-year history of transient ischemic attacks and weakness of the left extremities. Postcontrast computed tomography (CT) showed cord-like enhancement in the corpus callosum and pineal region. Magnetic resonance (MR) imaging demonstrated atrophy of the right hemisphere and multiple signal voids in the sulci. Cerebral angiography showed a diffuse AVM fed by the bilateral anterior cerebral and right middle cerebral arteries. The AVM nidus consisted of scattered nidi. Several draining veins appeared as multiple signal voids on MR images. No surgery was possible because of the scattered nidi. Left hemiparesis and mental retardation worsened, with progressive atrophy of the right hemisphere on serial MR images. Follow-up radiological examinations showed that the number of nidi increased, the draining vein enlarged, and the gyri calcified. The gyriform calcification on CT scans strongly resembled that seen in Sturge-Weber syndrome.

Cerebral Angiography↗
PubMed1993

[Treatment results of intra-arterial ACNU infusion chemotherapy for primary cerebral malignant lymphoma].

From May, 1987 to January, 1991, eight patients harboring primary cerebral malignant lymphoma (primary, six cases; recurrent, two cases) were treated by intra-arterial ACNU infusion chemotherapy. All but two cases also had hyperosmotic blood brain barrier (BBB) modification. Six primary cases had conventional teletherapy of 46-58.7 Gy (average 54.1 Gy) and one recurrent case had been irradiated again by 18 Gy. The follow-up period was 3 to 67.5 months (average 21.4 months). In six cases demonstrating measurable tumors on diagnostic images, all showed a complete response. The 1- and 2-year survival time was 50.0% and 37.5%, respectively, with a median survival time of 13.0 months. These were somewhat better than our previous results, but not better than those in the literature. Although intra-arterial ACNU infusion chemotherapy with BBB modification was not considered superior to other chemotherapy regimens, it yielded some long-surviving cases. Hence this chemotherapy is still worth using for treatment of primary cerebral malignant lymphoma.

Adult↗
PubMed1992

[Cephalic index in the case of chronic subdural hematomas; a preliminary report].

As a low cephalic index (cephalic index = breadth x 100/length), also called "dolichocephaly" has often been observed in patients with chronic subdural hematomas, the relation between the occurrence of chronic subdural hematoma and the cephalic index was investigated. 62 patients (male: 51, female: 11) with chronic subdural hematomas who were admitted during the past 5 years, and 62 patients (male: 51, female: 11) aged 40 years and over who visited the hospital for head injury which caused no intracranial hematoma, randomly sampled, as a control group, a total of 124 patients were studied for cephalic index on plain craniogram. The average cephalic index was 79.0 for males and 81.3 for females in the chronic subdural hematoma group, compared with 82.1 for males and 83.3 for females in the control group. The former index was lower than the latter for both sexes. Dolichocephaly was observed in 8 out of 51 males (15.7%) with chronic subdural hematomas while it was observed in only 1 out of 51 males (2.0%) in the control group. Since it has been reported that dolichocephaly depends on the development of arcus superciliaris and protuberantia occipitalis externa by the interaction between androgen and GH in males as well as time of closure of the cranial suture in childhood, and as androgen accelerates offensive behavior and GH stimulates the synthesis of collagen, the occurrence of chronic subdural hematoma is potentially related with sexual or individual variation in such endocrinic environments.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Chronic subdural hematoma with a markedly fibrous hypertrophic membrane. Case report].

A 40-year-old female, who had taken low-dose oral contraceptives for 2 months before onset, developed transient dysarthria, left hemiparesis, and left hemihypesthesia. One month later, a computed tomography (CT) scan revealed a uniformly enhanced, convex-shaped, hypertrophic membrane with a lobulated lumen in the subdural space of the right parietal region. A right parietal craniotomy was performed. The membrane, consisting of elastic-hard, hypertrophic granulation tissue and yellowish, sticky fluid in the lumen, was readily freed and totally extirpated. Subsequently, the patient recovered without persistent symptoms. Light microscopic examination detected the sinusoidal channel layer and the fibrous layer in an alternating configuration, along with intramembranous hemorrhagic foci. Such hypertrophy must have been caused by repeated intramembranous hemorrhages and reactive granulation. Such findings of hematoma membrane have never previously been reported. Thus, this is an interesting case, clearly distinguished from typical chronic subdural hematoma.

Adult↗