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Sadahiro Nomura

Publications and source records attributed to Sadahiro Nomura.

16 recordsLinked to original sources
PubMed2006

Various magnetic resonance imaging patterns of chronic subdural hematomas: indicators of the pathogenesis?

Magnetic resonance (MR) imaging can detect various patterns in chronic subdural hematomas. These patterns were compared to the computed tomography (CT) appearances and chemical analysis of the content in 60 hematomas from 44 patients. The hematomas could be classified into five types on both T(1)- and T(2)-weighted images: low, high, and mixed intensity, isointensity, and layered. Combining the T(1)- and T(2)-weighted images of all 60 hematomas revealed a total of 14 different imaging patterns. Combining the CT and MR imaging findings of 55 hematomas identified 25 different patterns. Analysis of the hematoma contents showed that hemolysis-related parameters, such as potassium, glutamate oxaloacetate transaminase, bilirubin, lactate dehydrogenase, and protein concentration, were markedly higher than in the peripheral blood, and there were significant correlations between these parameters. Mixed intensity hematomas were significantly thicker than the other types, and showed markedly higher values of hemolysis-related parameters. Factors affecting the CT and MR imaging findings, such as fresh bleeding, hemolysis, and hemoglobin changes, coexist in a hematoma to varying degrees, and these factors may interact with the age of the hematoma to produce the different patterns that are observed.

Adolescent↗
PubMed2006

Use of a Peltier chip with a newly devised local brain-cooling system for neocortical seizures in the rat. Technical note.

Local cortical cooling for termination of epileptic discharges (EDs) has recently become a focus of research. The authors report on a newly devised cooling system that uses a thermoelectric (Peltier) chip and examine the system's performance in experimental neocortical seizures. Experiments were performed in adult male Sprague-Dawley rats after induction of halothane anesthesia. The Peltier chip was attached to a heat sink with a water channel. Two silicon tubes were connected to the heat sink, and water at 37 degrees C was circulated in the channel. The newly designed device was placed on the surface of the cortex. Kainic acid (KA) was injected into the cortex to provoke EDs. In the nonepileptic cortex, the temperature of the cortical surface decreased to 14.8 +/- 1.5 degrees C and that 2 mm below the surface to 27.1 +/- 3.1 degrees C within 30 seconds after the start of cooling. The temperature of the heated side of the chip was maintained at approximately 36.9 degrees C. Without water circulation, the temperature of the cortical surface decreased to 20 degrees C but soon began to increase, peaking at 30 degrees C. The temperature of the heated side of the chip rose to more than 60 degrees C. The EDs, which appeared within 20 minutes after KA injection, began to decrease in amplitude immediately after cooling began and continued to decrease as the temperature of the cortex was lowered. Sufficient miniaturization and good performance of the cooling device was demonstrated. Further efforts to develop implantable cooling systems and improve existing ones should be continued.

Animals↗
PubMed2005

Association of intra- and extradural developmental venous anomalies, so-called venous angioma and sinus pericranii.

INTRODUCTION: We report a case of cerebellar venous angioma and parietal sinus pericranii. DISCUSSION: Venous angioma is classified as a developmental venous anomaly (DVA) because it is not a neoplasm but a variant that develops during embryogenesis. Sinus pericranii should be classified as extradural-type DVA. Although there have been few reports of association between these conditions, both are suspected to have the same pathogenesis, i.e., transient venous hypertension in the late embryonic period influencing venous development.

Central Nervous System Venous Angioma↗
PubMed2005

Systemic administration of argatroban reduces secondary brain damage in a rat model of intracerebral hemorrhage: histopathological assessment.

This study investigated the effects of argatroban, a thrombin inhibitor, on brain edema and inflammation in a rat intracerebral hemorrhage (ICH) model. ICH was induced by injecting collagenase IV into the right caudate nucleus. Argatroban was administered intraperitoneally. Argatroban reduced brain edema from 44.6 to 14.3 microl at 72 h. Infiltration of polymorphonuclear leukocytes at 24 h and monocyte/macrophage at 24 and 72 h was significantly suppressed by argatroban. Argatroban did not increase the volume of hematoma. Systemic administration of argatroban reduced secondary brain damage including edema and inflammation in a rat ICH model.

Animals↗
PubMed2005

Effect of cell phone magnetic fields on adjustable cerebrospinal fluid shunt valves.

The rapid increase in the number of cell phone users has led to the suggestion that electromagnetic waves might affect medical devices. Cerebrospinal fluid shunt valves contain a magnetic device to allow the intracranial pressure setting to be adjusted transcutaneously. Among the valves tested, the settings of the Strata valve, the Hakim valve, and the Sophy valve were affected by magnetic flux densities of 6.0, 17.5, and, 40.0 mT, respectively. Cell phones produce a magnetic flux density of 3.0 to 40.0 mT. Although cell phones could theoretically influence shunt valves, this seems unlikely because the flux density decreases with the square of the distance.

Cell Phone↗
PubMed2005

Management of patients with cavernous angiomas presenting epileptic seizures.

BACKGROUND: The aim of this study was to establish a treatment strategy for patients with cavernous angiomas and have seizures. METHODS: We analyzed retrospectively 31 patients with cavernous angiomas presenting with seizures. Of the 31 patients, 15 (11 men, 4 women) had been treated medically (the medical group) and 16 (11 men, 5 women) had been treated surgically (the surgical group). The percentage of patients who became seizure-free and the number of anticonvulsants used were compared between these 2 groups. The mean follow-up period was 5.3 years (range, 7 months-10 years). There was no statistically significant difference between the 2 groups with regard to the number of patients, sex, age, and follow-up period. RESULTS: The percentage of patients who became seizure-free was higher in the surgical group than in the medical group (80% vs 19%, P < .01). The number of anticonvulsants required was reduced in the surgical group after surgery (from 1.5 +/- 0.7 to 1.1 +/- 0.8, P < .01) and was not reduced after in the medical group. CONCLUSIONS: Surgical intervention may have greater benefits than medical intervention for patients with cavernous angiomas presenting with epileptic seizures.

Adult↗
PubMed2004

[A case of intractable epilepsy presenting epileptic spasm treated with callosotomy in childhood].

We present a case of intractable epilepsy presenting epileptic spasm successfully treated with anterior callosotomy in childhood. A 12-year-old boy had seizures frequently since the age of 11 months which were diagnosed as an infantile spasm. He underwent various treatments including ACTH therapy, but the seizures were intractable. Characteristics of his seizures were an abrupt axial movement leading to sustained posturing, most often truncal, and neck flexion with pronounced arm extension and abduction. He lost consciousness transiently and these seizures frequently occurred in clusters and the duration of seizure was 1 to 3 seconds. Neurologically he had no deficit, but his intelligence was below the standard level. Magnetic resonance image (MRI) showed no abnormalities in the brain. Electroencephalogram (EEG) demonstrated secondary bilateral synchrony (SBS) with left frontal dominance in amplitude. Subdural strip electrodes were implanted bilaterally over the frontal lobes to detect an epileptogenic region. However intracranial ictal-EEG demonstrated an abrupt bilateral desynchronization for 1-3 seconds. As the epileptogenic zone was not clearly identified and an abrupt bilateral desynchronization was identified, anterior callosotomy was performed. Since surgery, he has remained seizure-free for two years while taking anticonvulsants and the SBS has disappeared. This case may indicate that the corpus callosum influences the occurrence of epileptic spasm and SBS on EEG.

Child↗
PubMed2002

Subarachnoid hemorrhage caused by dural arteriovenous fistula of the sphenobasal sinus--case report.

A 59-year-old woman presented with a rare middle fossa dural arteriovenous fistula (AVF) unrelated to the cavernous sinus manifesting only as subarachnoid hemorrhage. Angiography revealed shunts between the meningeal branches of both the internal and external carotid arteries and the sphenobasal sinus. The AVF drained into the superficial middle cerebral vein (SMCV) which had a varix and an anastomosis to a superior cerebral vein. The arterial supply vessels were eliminated surgically and the sinus was excised. Bleeding did not recur and there was no venous infarction. Dural AVF of the sphenoparietal sinus is associated with pulsatile exophthalmos and dural AVF of the sphenopetrosal sinus with tinnitus, but dural AVF of the sphenobasal sinus has no obvious symptom. Simple interruption of the SMCV at the penetration of the arachnoid membrane was possible because of the absence of a draining vessel to preserve AVF patency, but the arteries were eliminated in this patient to prevent formation of another AVF.

Carotid Arteries↗
PubMed2002

Calcified metastatic brain tumor--two case reports.

A 29-year-old man and a 46-year-old woman presented with calcified brain metastasis from pulmonary adenocarcinoma. Both patients had a relatively benign clinical course and prolonged survival after total removal of the tumors. The male patient was still alive 2 years 3 months after surgical resection of the metastatic and primary tumors. The female patient had had brain metastasis 8 years after surgical resection of lung cancer, and survived for 3 years 3 months after removal of the brain metastasis. The MIB-1 indexes of the two cases were relatively low compared with other cases of brain metastases. Calcification and low MIB-1 index may indicate longer survival in patients with metastatic tumors if the primary tumor is controlled.

Adenocarcinoma↗
PubMed2002

Neuro-Behçet's disease manifesting as a neoplasm-like lesion--case report.

A 50-year-old man presented with neuro-Behçet's disease (NBD) manifesting as a large neoplasm-like lesion affecting the brainstem, basal ganglia, and white matter of the cerebral hemisphere. He had no history of disease except for psychoneurosis. On admission, neurological examination found left hemiparesis and dysarthria. Magnetic resonance (MR) imaging showed multiple small ring-like enhancement in the basal ganglia, brainstem, and deep white matter. Biopsy of the mass was performed. Histological examination revealed invasion of inflammatory cells in the white matter, especially around the blood vessels. After the brain biopsy, the patient developed oral aphthae, genital ulcers, and skin eruptions, which are indicative of Behçet's disease. MR imaging after three courses of steroid pulse therapy revealed that the edematous lesion had become smaller with minimum midline shift. NBD should be considered in the differential diagnosis of lesions with multiple ring-like enhancement extending from the basal ganglia to the brainstem, because dermatological manifestations are sometimes obscured during periods of remission.

Behcet Syndrome↗
PubMed2002

Endoscopic fenestration of posterior fossa arachnoid cyst for the treatment of presyrinx myelopathy--case report.

A 32-year-old man presented with an arachnoid cyst of the posterior fossa manifesting as cervical syringomyelic myelopathy. Magnetic resonance (MR) imaging demonstrated edematous enlargement and T2 prolongation of the cervical spinal cord, indicating a "presyrinx" state. MR imaging showed the inferior wall of the cyst, which disturbed cerebrospinal fluid (CSF) pulsatile movement between the intraspinal and intracranial subarachnoid spaces. The cyst wall was fenestrated with a neuroendoscope. The presyrinx state and the CSF movement improved. Posterior fossa arachnoid cyst, as well as Chiari malformation, can cause CSF flow disturbance at the craniocervical junction and syringomyelia. Endoscopic fenestration is less invasive than foramen magnum decompression and should be the procedure of choice.

Adult↗
PubMed2002

[Dissecting aneurysm of the middle cerebral artery with subarachnoid hemorrhage showing complete occlusion at the M2 portion of the middle cerebral artery on preoperative angiograms: case report].

We present a surgical case of a dissecting aneurysm of the middle cerebral artery associated with subarachnoid hemorrhage and intracranial hemorrhage. A 29-year-old man suddenly fell into a comatose state, and was referred to our hospital. CT scan showed diffuse subarachnoid hemorrhage and an intracerebral hematoma with marked midline shift located in the right frontal lobe. The right carotid angiogram revealed complete occlusion at the M2 portion of the middle cerebral artery, but failed to reveal any aneurysms in the rest of the intracranial circulation. We undertook emergent surgery to evacuate the hematoma and to confirm whether it was a dissecting aneurysm or not. After evacuation of the hematoma of the right frontal lobe, the Sylvian fissure was noticed to be widely opened. We detected a large dissecting aneurysm with a dark-purplish wall arising from the right M2 trunk, and we trapped the aneurysm. The postoperative course was uneventful and the patient gradually improved and was discharged without neurological deficits. We presented this case with a review of the literature.

Adult↗