Biomedical subjects

S Ushikoshi

Publications and source records attributed to S Ushikoshi.

16 recordsLinked to original sources

PubMed2001

Treatment outcome of single or hypofractionated single-isocentric stereotactic irradiation (STI) using a linear accelerator for intracranial arteriovenous malformation.

BACKGROUND AND PURPOSE: We investigated the use of hypofractionated stereotactic radiotherapy (HFSR) to reduce adverse radiation effects in comparison to single-fraction stereotactic radiosurgery (SRS) for intracranial arteriovenous malformations (AVMs). MATERIALS AND METHODS: This study includes 53 intracranial AVMs treated between 1991-1998. HFSR was selected for 26 AVMs with a maximum diameter > or 2.5 cm or at eloquent area. Twenty-seven patients were treated with SRS (18 AVMs < 2.5 cm at non-eloquent area, nine patients who were unfit for prolonged ring-wearing). The most frequent minimum dose (Dmin) was 20 Gy for SRS and 28 Gy for HFSR in four fractions. The mean follow-up duration was 34.6 months for SRS and 35.4 months for HFSR. RESULTS: As a whole, the 3 and 5-year actuarial obliteration rates were 64 and 92%. Age <20 years old (P=0.02) and a maximum diameter <2 cm were favorable factors (P=0.05). A difference in the distribution of patients was observed in size (> or =2.5 cm or not) (P<0.001) and location (eloquent or not) (P<0.001) between SRS and HFSR due to the treatment selection. However, no significant differences were observed in the actuarial rates of obliteration and transient increased signals with T2-weighted MR images between SRS and HFSR. Radiation necrosis occurred in two patients treated with SRS and in none with HFSR. Intracranial hemorrhage after treatment happened in two treated with SRS and three with HFSR. CONCLUSIONS: HFSR appears to be at least as effective as SRS in achieving complete obliteration of intracranial AVM, although its definitive role remains to be investigated.

Adolescent↗

PubMed2001

[Diagnosis of cerebral aneurysm using 3-dimensional digital subtraction angiography].

Recent rapid advancement in the technology of magnetic resonance angiography and 3-dimensional computed tomography angiography has opened the door to a less-invasive diagnostic routine for the treatment of cerebral aneurysms. However, from the viewpoint of decision making concerning which treatment to use; conservative therapy; surgical intervention; or endovascular treatment, much more precise information is necessary. Recent progress of rotation digital subtraction angiography has introduced 3-dimensional digital subtraction angiography. In the past year, 28 cases involving 39 aneurysms have been studied using 3-dimensional angiography. This study was carried out, using a rotating C-arm, which rotates 220 degrees in 5.8 seconds. All raw data gathered was transferred to the workstation for image reconstruction. The purpose of this study was to evaluate the clinical potential of 3-dimensional digital subtraction angiography for the diagnosis of the cerebral aneurysms.

Angiography, Digital Subtraction↗

PubMed2001

[Two cases of "steal VBI" with stenosis of the internal carotid artery].

Although previous reports have suggested "steal VBI" due to occlusive carotid artery diseases, there have been no reports that clearly define "steal VBI" from the viewpoint of cerebral hemodynamics. The authors presented two cases with "steal VBI" due to severe stenosis of the internal carotid artery. Both patients had well-developed collateral circulation through the ipsilateral posterior communicating artery. Although no occlusive lesion was found in the vertebrobasilar system, blood flow studies revealed impaired hemodynamics in the contralateral occipital lobe, which fact correlated with their neurological deficit, visual field disturbance. Carotid stenting markedly corrected the stenotic lesions, leading to neurological improvement. Follow-up blood studies showed normalization of hemodynamics in the contralateral occipital lobe. The findings strongly suggest that carotid surgery or stenting can improve cerebral hemodynamics in the carotid systems, resolving "steal VBI" due to developed collaterals from the posterior to the anterior circulation.

Carotid Artery, Internal↗

PubMed2001

[Angioplasty with stenting for intracranial vertebral and basilar artery stenosis: three technical case reports and literature review].

Patients with intracranial vertebral artery (VA) or basilar artery (BA) stenosis have been mainly treated with medication. However, it has been reported that about 10% of patients experience restroke in the VBA territory, with a high rate of morbidity and mortality. Percutaneous transluminal angioplasty (PTA) is regarded as one of the treatments although it carries the risk of restenosis, recoil or dissection. Stent placement is, therefore, considered to be a further option for the treatment of intracranial artery stenosis since it can prevent the restenosis. We report three medical refractory cases of intracranial VA (2 cases) or BA stenosis (1 case) treated with stenting, none of which had complications and their symptoms disappeared or diminished. Angioplasty with the use of a stent device is regarded as a useful treatment for intracranial artery stenosis, but its risk and long-term result need to be investigated further.

Aged↗

PubMed2001

[Intentional neck-plastic incomplete clipping followed by coil embolization for broad-necked distal BA aneurysms].

OBJECTIVE: We report three patients with broad-necked distal basilar artery (BA) aneurysms treated with intentional incomplete clipping followed by endovascular occlusion using Guglielmi detachable coils. METHODS: The location of the aneurysms was BA bifurcation in one patient and BA-superior cerebellar artery (SCA) in two. One patient presented with acute subarachnoid hemorrhage and two patients had incidental aneurysms. In two patients, endovascular treatment was thought to be difficult considering the morphology of the aneurysms and surgical treatment was performed as the first choice of treatment. One patient with a BA-SCA aneurysm underwent endovascular treatment using a remodelling technique first. However, it was impossible to place the coil preserving SCA, so surgical treatment was performed. In all patients, the attempt to pursue complete clipping was considered to be accompanied with high risks of morbidity, so neck-plastic incomplete clipping was performed intentionally. One to six days after the surgery, coil embolization was performed. RESULTS: In all patients, complete occlusion of the aneurysms was achieved and all patients had excellent clinical outcomes. CONCLUSION: Intentional neck-plastic incomplete clipping followed by endovascular coiling may be a useful treatment option for patients with broad-necked distal BA aneurysms.

Aged↗

PubMed2000

[Clinical application of portable near infrared oximetry (HEO-200) to neurosurgical monitoring].

Near infrared spectroscopy (NIRS) have been accepted as a useful modality for non-invasive monitoring of brain oxygenation state. Using a newly developed NIRS apparatus, HEO-200, the authors continuously monitored the changes in the oxygenation state of brain hemoglobin during carotid endarterectomy (CEA) or carotid balloon occlusion tests (BOT) in 21 patients. Somatosensory evoked potentials (SEP), regional cerebral blood flow (rCBF) or transcranial Doppler sonography (TCD) were also employed to compare with the NIRS-responses. In 7 of 21 patients, the carotid artery occlusion caused a continuous deoxygenation of brain hemoglobin as well as a decrease in total hemoglobin. These findings correlated well with temporary neurological deficits and a marked reduction of rCBF in the ipsilateral hemisphere in patients who underwent carotid BOT under local anesthesia. The patients also showed a marked decrease in the N20 amplitude of SEP during CEA under general anesthesia. Restoration of blood flow immediately resolved these findings. The other 14 patients demonstrated no or only transient changes on NIRS as well as on SEP and rCBF study. HEO-200 could non-invasively monitor the relative changes of cerebral oxygenation state with good time resolution, and detect critical ischemia during CEA and carotid BOT.

Aged↗

PubMed1999

Effect of water extracts of Rhizopus delemar on the stimulus coupled responses of neutrophils and their modulation by various protein kinase inhibitors.

Human peripheral blood polymorphonuclear leukocytes were preincubated with water extracts from Rhizopus delemar. The water extracts significantly inhibited arachidonic acid induced superoxide generation, whereas enhanced superoxide generation induced by phorbol 12-myristate 13-acetate but not those induced by N-formyl-methionyl-leucyl-phenylalanine. Superoxide generation induced by water extracts was inhibited by staurosporine, an inhibitor of protein kinase C, and was enhanced by genistein, an inhibitor of tyrosine kinase. The water extracts incubated with phorbol 12-myristate 13-acetate markedly increased phosphorylation of serine residue of 28.5 kDa protein with time and the phosphorylation depended on the concentration of the water extracts, whereas the water extracts incubated with arachidonic acid decreased the phosphorylation of serine residue of 38 and 42 kDa proteins. The phosphorylation of 28.5 kDa protein induced by the water extracts was inhibited by staurosporine, an inhibitor of protein kinase C, but was not inhibited by genistein, an inhibitor of tyrosine kinase.

Enzyme Inhibitors↗

PubMed1999

Vertebral arteriovenous fistula that developed in the same place as a previous ruptured aneurysm: a case report.

BACKGROUND: Aneurysms of the extracranial vertebral artery (VA) and vertebral arteriovenous fistulas (VAVFs) are relatively rare diseases. The most frequent cause of both diseases is trauma. Atraumatic lesions are less common. Presented here is a case of atraumatic AVF of the extracranial VA that developed in the same location as a previous ruptured aneurysm of the ipsilateral VA that was originally treated by proximal occlusion 11 years earlier. METHODS: A 40-year-old woman presented with a massive hematoma in the upper posterior neck region caused by the rupture of an extracranial VA aneurysm. Proximal occlusion of the VA was performed by use of a detachable balloon. She enjoyed good health for 11 years, then she noticed a pulsatile bruit. Angiograms revealed an AVF between the left VA that was fed by collateral circulation and the paravertebral venous plexus. Incidentally found were soft tissue masses in the left retroauricular and the right suboccipital regions. Also, skull X-ray films showed multiple bony defects. Biopsy of the subcutaneous mass was performed in the hope of obtaining clues as to which pathological processes had weakened the artery. RESULTS: As direct transarterial access to the fistula was out of the question, the fistulous compartment of the paravertebral venous plexus was tightly packed with multiple platinum coils effected by the transfemoral approach. A histological examination of the specimen revealed features of a neurofibroma, and a diagnosis of neurofibromatosis Type 1 was established. CONCLUSIONS: In this case, transvenous embolization of the VAVF was successfully performed. The fragility of the arterial wall, related to neurofibromatosis Type 1, was considered to contribute to the development of the aneurysm and AVF.

Adult↗

PubMed1999

Functional prognosis after treatment of spinal dural arteriovenous fistulas.

Functional prognosis after treatment for spinal dural arteriovenous fistulas (SDAVFs) was retrospectively analyzed in 13 consecutive patients aged 38 to 73 years (mean 57 years) treated during the last 5 years. The duration of symptoms before diagnosis ranged from 3 to 72 months (mean 23 months). Neurological symptoms were examined before and 6 months after the treatment. Seven patients underwent embolization as the initial treatment. In four of six patients, N-butyl 2-cyanoacrylate (NBCA) embolization achieved complete obliteration of SDAVF. The other two patients with incomplete embolization and one embolized with polyvinyl alcohol particles underwent subsequent surgical treatment. Six patients were treated by direct surgery. Complete disappearance of SDAVF was confirmed in all nine patients treated surgically. Improvement of gait and micturition disturbance after the treatment was noted in six of 10 and three of six patients, respectively. Long duration of symptoms and high grade of neurological symptoms were associated with a poor functional outcome. NBCA embolization and surgery are curative treatments for SDAVF, but the functional prognosis is not always satisfactory. Embolization is the first choice of treatment for SDAVF because it is less invasive and relatively safe. However, when complete obliteration is not achieved, prompt surgery is recommended because a long duration of symptoms will result in a poor functional prognosis.

Adult↗

PubMed1999

Aggravation of brainstem symptoms caused by a large superior cerebellar artery aneurysm after embolization by Guglielmi detachable coils--case report.

An 81-year-old male presented with right oculomotor nerve paresis and left hemiparesis caused by a mass effect of a large superior cerebellar artery aneurysm. Endovascular treatment was performed using Guglielmi detachable coils. The patient subsequently suffered aggravation of the mass effect 3 weeks after the embolization. Bilateral vertebral artery occlusion was performed, which decreased the cerebral edema surrounding the aneurysm, but his neurological symptoms did not improve. Parent artery occlusion is recommended as the first choice of treatment for an unclippable large or giant aneurysm causing a mass effect on the brainstem.

Aged↗

PubMed1999

Multiple dural arteriovenous shunts in a 5-year-old boy.

We describe a rare case of multiple dural arteriovenous shunts (DAVSs) in a 5-year-old boy. MR imaging performed at 1 year of age showed only a dilated anterior part of the superior sagittal sinus; however, angiography at 5 years of age revealed an infantile-type DAVS there and two other DAVSs of the adult type. The pathophysiological evolution of DAVSs in children and their treatment strategies are discussed.

Angiography↗

PubMed1998

Spinal intrathecal actinomycosis: a case report.

BACKGROUND: Actinomycosis of the central nervous system is a rare disease that most frequently forms cerebral abscesses. In the present report, we describe an extremely rare case of spinal intrathecal actinomycosis. CASE PRESENTATION: A 33-year-old man presented with high fever followed by back pain and paraparesis. Magnetic resonance imaging (MRI) with gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) enhancement (Gd-MRI) displayed an irregularly enhanced mass lesion at the thoraco-lumbar junction that mimicked an intramedullary tumor with exophytic growth. Surgical exploration 7 months after the onset of the high fever revealed intrathecal granulation tissue with small abscess formation. Another surgical exploration was carried out 2 months after the first operation because the patient developed progressive paraparesis and showed an intrathecal ring-like enhancement that was detected with Gd-MRI. Actinomyces organisms were finally identified histologically in the surgical specimen. CONCLUSIONS: The clinical course and serial changes of Gd-MRI findings are important considerations when this rare and infectious spinal lesion is suspected.

Abscess↗

PubMed1998

Postoperative hyperperfusion in dural arteriovenous fistula associated with venous ischemia: case report.

BACKGROUND: It is well known that carotid endarterectomy and extracranial-intracranial arterial bypass sometimes cause postoperative hyperperfusion, and vasoparalysis attributable to long-standing ischemia has been suggested as the cause. It is also well known that dural arteriovenous fistula (AVF) sometimes causes cerebral ischemia attributable to venous hypertension. However, there are few reports regarding the postoperative changes of regional cerebral blood flow (rCBF). METHODS: We report a case of dural AVF of the left transverse/sigmoid sinuses, occurring in a 64-year-old man. Intraoperative transvenous embolization combined with transarterial embolization was performed, and the rCBF was measured pre- and postoperatively using 99mTc-hexamethyl-propylene amine oxime and single-photon emission computed tomography (SPECT). RESULTS: Preoperative SPECT disclosed a marked rCBF reduction in the left temporal, parietal, and occipital lobes. Complete obliteration of the AVF was attained after the intraoperative transvenous embolization, without any neurological deterioration. However, postoperative SPECT demonstrated temporary hyperperfusion in these regions. CONCLUSIONS: Sudden resolution of venous ischemia can lead to postoperative hyperperfusion, and pre- and post-treatment rCBF studies are important to prevent complications related to hyperperfusion.

Arteriovenous Fistula↗

PubMed1998

Multiple dural arteriovenous fistulas.

Four patients with multiple intracranial dural arteriovenous fistulas (DAVFs) at separate sites were treated by endovascular techniques (transarterial and/or transvenous embolization), surgery (excision or isolation), radiotherapy, or combinations, according to the pathophysiological condition. All lesions in two patients were obliterated completely without neurological deficit. There were residual fistulas after the treatment in two patients, but these were low-grade lesions without retrograde cortical venous drainage, and marked clinical improvement was obtained. Planning of treatment strategies for multiple DAVFs requires careful analysis of the venous drainage from the affected sinuses and cerebral hemodynamics.

Aged↗

PubMed1997

Cerebral abscess as an unusual complication of coil embolization in a dural arteriovenous fistula. Case report.

This 63-year-old man presented with a right temporoparietal cortical infarction. A dural arteriovenous fistula involving the right transverse sinus was diagnosed on cerebral angiography. Transvenous embolization using detachable coils was performed; however, postembolization angiograms demonstrated retrograde filling of a cortical draining vein that was not seen on initial angiography. The patient subsequently developed a cerebral abscess in the region of the previous cortical infarction 2 months after the embolization. The abscess was successfully treated with drainage and antibiotic therapy. The authors report this case to illustrate an unusual complication associated with this procedure and the possible contribution of the cortical draining vein in the pathogenesis of the cerebral abscess.

Angiography, Digital Subtraction↗

PubMed1996

Ruptured aneurysm of the middle meningeal artery associated with occlusion of the posterior cerebral artery. Case report.

The authors describe the case of a 69-year-old man with an intracerebral hemorrhage due to rupture of a nontraumatic aneurysm of the middle meningeal artery (MMA). The ipsilateral posterior cerebral artery (PCA) was occluded, and dural anastomoses developed as the main collateral pathway between the MMA and the cortical branch of the PCA, on which the aneurysm was located. It is considered that increased hemodynamic stress to the collateral pathway contributed to the formation of the aneurysm.

Aged↗