Biomedical subjects

Toshi Abe

Publications and source records attributed to Toshi Abe.

14 recordsLinked to original sources

PubMed2004

Non-herpetic acute limbic encephalitis: cerebrospinal fluid cytokines and magnetic resonance imaging findings.

OBJECTIVE: Non-herpetic acute limbic encephalitis (non-herpetic ALE) is regarded as a new subgroup of limbic encephalitis. In the present study, clinical findings and cerebrospinal fluid (CSF) cytokines in patients with non-herpetic ALE were investigated. PATIENTS AND METHODS: For adult inpatients in our hospital and related hospitals from 1996 to 2001, non-herpetic ALE was examined according to the criteria described in this study. Six patients were diagnosed as having non-herpetic ALE, and their clinical data and magnetic resonance imaging (MRI) were analyzed. In the CSF samples of the 6 patients with non-herpetic ALE and 6 patients with herpes simplex encephalitis (HSE), the concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and interferon (IFN)-gamma were determined using sandwich-type enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: The six patients with non-herpetic ALE showed all the acute encephalitis features, such as fever, altered consciousness, seizures, memory impairment, and mild CSF pleocytosis. MRI demonstrated selective abnormal signals in the limbic system, including the bilateral hippocampi and amygdalae. The levels of CSF IL-6 and IFN-gamma in patients with non-herpetic ALE were significantly lower than those in patients with HSE (p<0.05 and p<0.01, respectively). The levels of both TNF-alpha and IL-1beta were below the detection limits in both groups. CONCLUSION: Six patients were newly diagnosed as having non-herpetic ALE in this study. These patients revealed both acute limbic encephalitis and MRI abnormalities in the bilateral hippocampi and amygdalae. The levels of IL-6 and IFN-gamma in the CSF of patients with non-herpetic ALE were significantly lower than those of patients with HSE, possibly reflecting an immunological process in this type of ALE rather than direct viral infection.

Acute Disease↗

PubMed2004

Conformity of carotid stents with vascular anatomy: evaluation in carotid models.

BACKGROUND AND PURPOSE: Conformity between self-expanding Wallstents and vascular anatomy is limited. Because of a lack of longitudinal flexibility, straightening effects on vascular curves occur and may result in stent-induced kinking. Our purpose was to evaluate the conformity of self-expanding stents with the course and endoluminal surface of silicone models of the normal human carotid artery. METHODS: Five different types of self-expanding carotid stents were implanted into simplified pulsatile perfused silicone models of the carotid bifurcation. The models embody elastic properties of the vessel wall similar to those of normal human arteries. All stents had the same nominal diameter and length and bridged the external carotid artery origin as well as a consecutive curve at the initial segment of the internal carotid artery. Conventional radiographs of the model were compared before and after stent placement to record changes of shape and course of the silicone artery. Dehiscences between stent filaments and arterial wall were measured on digital subtraction angiograms of the model. RESULTS: Implantation of braided Wallstents or the Expander with continuous filaments induced considerable straightening effects on the bifurcation angle, as well as on the curves of the internal carotid artery. Segmented designs of modular nitinol stents complied better with vascular tortuosity and showed improved adaption between stent and the endoluminal surface of the model. CONCLUSION: Model experiments show that segmented nitinol stents improve the conformity between the prosthesis and vascular anatomy, and confirm new carotid stent concepts as an alternative to the Wallstent.

Alloys↗

PubMed2004

[Angiography].

The clinical usefulness of three dimensional images was widely recognized. The three dimensional digital subtraction angiography (3D-DSA) well demonstrated anatomical structures of cerebral arteries with high special resolution. This 3D observation allowed high quality planning for aneurysmal coil packing and neck clipping. Because of the bony structure and curvy arterial anatomy in the skull base region, 3D-CTA and MRA was sometimes distureved the demonstration of the anatomical relationship adjacent to the aneurysm. However, 3D-DSA not only demonstrated arterial anatomy, but also analyzed of vascular structure, quantifiably. And it was useful in radiation dose reduction by reduction of DSA exposure number. We believe that 3D-DSA should provided useful information for planning of surgical and endovascular treatment in the field of cerebro-vascular disease.

Angiography, Digital Subtraction↗

PubMed2004

[A successfully treated case of a ruptured anterior wall aneurysm of the internal carotid artery (C2) which changed in form from blister-like to saccular type].

We successfully treated a case of ruptured anterior wall aneurysm of the ICA (C2) which changed in form from blister-like to saccular type. A 46-year-old woman developed subarachnoid hemorrhage on July 12, 2002. Cerebral angiogram demonstrated a blister-like aneurysm located in the left C2 portion of the internal carotid artery, but which didn't affect the arterial branches. Because of the risk of premature rupture during early surgery, delayed surgery was scheduled and the patient underwent serial study of the aneurysm. During 2 weeks of follow-up, the shape and size of the aneurysm changed in form blister-like to an enlarged saccular type aneurysm. On the day 18th, a left episubcombined approach, after insertion of a balloon catheter into the cervical ICA, was attempted and the aneurysm projecting antero-medially under the left carotid artery was exposed. The aneurysm had a distinct neck and its wall was not fragile. There was no macroscopic evidence of dissection of the ICA and the aneurysm was successfully clipped by conventional manipulation. Because of the difficulty in determining by angiographic evidence alone, whether an anterior wall aneurysm is a blister type or saccular type, careful follow-up is needed and if the shape or size changes, immediate appropriate treatment becomes mandatory. Intraoperative observation will determine the final diagnosis, as in this uncommon case.

Aneurysm, Ruptured↗

PubMed2003

Small peripheral pulmonary carcinomas evaluated with dynamic MR imaging: correlation with tumor vascularity and prognosis.

PURPOSE: To correlate the findings at contrast material-enhanced dynamic magnetic resonance (MR) imaging of small peripheral pulmonary carcinomas with tumor vascularity and prognosis. MATERIALS AND METHODS: Ninety-four patients with small peripheral pulmonary carcinomas who underwent surgical resection were examined retrospectively. Pathologic specimens were stained with hematoxylin-eosin and elastin-van Gieson. CD34 and vascular endothelial growth factor (VEGF) were assessed immunohistochemically. Delineated CD34-positive cells were counted as microvessels. Dynamic MR imaging was performed prior to and at 1, 2, 3, 4, 5, 6, and 8 minutes after injection of a bolus of gadopentetate dimeglumine. The two observers reviewed all images, and two pathologists performed all histologic analyses; a decision was determined with consensus. The maximum enhancement ratio (MER), the time lapse between the completion of the injection and the point of maximum signal intensity (Tmax), the washout ratio, and the slope value of the time-signal intensity curve were correlated with the microvessel density. VEGF-positive and VEGF-negative tumors were compared. All statistical analyses were performed by using nonparametric methods. RESULTS: The MER and the slope value were positively correlated, and the Tmax was negatively correlated (Spearman rank test, P <.0001, all comparisons) with the microvessel counts. The distribution of elastic and collagen fibers correlated with the washout ratio (Kruskal-Wallis test, P <.001). There was a statistically significant difference between the slope value of VEGF-positive tumors and that of VEGF-negative tumors (Mann-Whitney U test, P <.0001). Patients with VEGF-positive tumors had a significantly shorter overall survival than did those with VEGF-negative tumors (log-rank test, P <.0001). CONCLUSION: Dynamic MR imaging findings correlate with tumor vascularity and may be helpful in the prediction of prognosis.

Adenocarcinoma↗

PubMed2003

Bilateral anomalous posterior inferior cerebellar artery-anterior inferior cerebellar artery anastomotic arteries associated with a ruptured cerebral aneurysm--case report.

A 50-year-old man presented with subarachnoid hemorrhage from a ruptured cerebral aneurysm arising from a left posterior inferior cerebellar artery (PICA)-anterior inferior cerebellar artery anastomotic artery manifesting as severe headache, obtundation, and quadriplegia. Conventional and three-dimensional digital subtraction angiography showed that the anastomotic complex was present bilaterally and both vertebral arteries terminated at the origin of the PICA. The identification of this anomalous vascular network allowed coil embolization of the broad-based aneurysm with occlusion of the parent artery. The patient had residual moderate disturbance of consciousness and quadriplegia before transfer for rehabilitation.

Aneurysm, Ruptured↗

PubMed2002

Study of image findings in rapid eye movement sleep behavioural disorder.

To elucidate the cause of idiopathic rapid eye movement (REM) sleep behavior disorder (RBD), magnetic resonance imaging and single-photon emission computed tomography of the brain were conducted on 20 patients with RBD. Blood flow in the upper portion of both sides of the frontal lobe and pons was significantly lower in patients with RBD than in the normal elderly group. Among the patients with RBD, decreased blood flow in the frontal lobe showed no correlation with the extent of frontal lobe atrophy. Decreased blood flow in the upper portion of the frontal lobe and pons might be associated with the pathogenesis of idiopathic RBD.

Aged↗

PubMed2002

Antiphospholipid syndrome and multiple ischemic strokes in a patient with myasthenia gravis.

Little is known about ischemic stroke occurrence in patients with myasthenia gravis (MG), although antiphospholipid antibodies are detectable in many MG patients. A 47-year-old woman with a 20-year history of generalized MG had an acute onset of right hemiparesis. She had undergone thymectomy 10 years previously and was treated for phlebothrombosis of the lower extremity 3 years previously. Computed tomography (CT) demonstrated an old infarct in the left frontal lobe and a new lesion in the right parietal lobe. Multiple small cortical and subcortical infarcts were demonstrated on fluid attenuated inversion recovery (FLAIR) images. Thrombocytopenia (5.9 x 10(4)/microL), a prolonged activated partial thromboplastin time (aPTT; 50.2 sec), and an elevation of beta 2-IgG-glycoprotein I anticardiolipin antibodies (beta 2-GPIaCL; 55.7 U/mL) were observed. Neurological defects improved significantly over 2 weeks. She then was treated with oral prednisolone (30 mg/day) for 18 months, with resolution of laboratory abnormalities and no new cerebrovascular events or findings on imaging. We believe that our patient's multiple infarcts are caused by antiphospholipid antibodies and recommend glucocorticoid therapy to prevent recurrent of ischemic stroke in similar case.

Antiphospholipid Syndrome↗

PubMed2002

[Experimental study of pseudo-stenosis artifact on three-dimensional DSA].

Rotational three-dimensional digital subtraction angiography (3D-DSA) is very useful for interventional neuroradiology, especially in the endovascular therapy of cerebral aneurysms. However, pseudo-stenosis artifact on the vessel, which runs vertically to the rotational axis, was observed clinically. In this study, this artifact was confirmed in an experiment with 4.5-millimeter diameter vessel phantoms. The attenuation of the phantom at each degree of exposure (44 directions) was measured on the workstation (DSA pixel value). DSA pixel values were plotted from data of 10, 20, 30, 40, and 50 millimeter lengths, respectively. The saturated DSA pixel value of tangent projection on phantoms of 30 millimeters or more in length was observed. This phenomenon induces pseudo-stenosis artifact on 3D-DSA. The maximum reduction in the diameter of the phantom was 27.4% on the length of 50 millimeters. We confirmed that the two-dimensional data vertical to the rotational axis were inaccurate when a straight-coursed, long, segmented vessel was present. Under this special condition, vessels on 3D-DSA were displayed as smaller than their actual diameter.

Angiography, Digital Subtraction↗

PubMed2002

Clinical benefits of rotational 3D angiography in endovascular treatment of ruptured cerebral aneurysm.

BACKGROUND AND PURPOSE: Recent neurointerventional and neurosurgical technologies require an understanding of lesions and adjacent structures in three dimensions. To clarify the clinical benefits of rotational 3D digital subtraction angiography (DSA), we retrospectively analyzed its advantages and disadvantages at the time of interventional procedures for ruptured cerebral aneurysms. METHODS: From January 1998 through September 2000, 85 patients with a ruptured cerebral aneurysm were treated with Guglielmi detachable coils in the acute phase. Data for the patients treated before availability of 3D DSA (group A, 52 patients) were compared with data for patients treated after availability of 3D DSA (group B, 33 patients). Variables analyzed were age, sex, location of aneurysm, size of aneurysm, number of implanted coils, number of DSA exposures, and total amount of contrast medium used. RESULTS: No statistically significant differences between the groups were noted when we compared the age, sex, aneurysm location, aneurysm size, and number of implanted coils. The number of DSA exposures was decreased in total by using 3D DSA (P <.0001), not only to determine the working projection (P <.0001) but also during the procedure (P <.0002). However, no statistically significant difference was noted in the comparison of total amount of contrast medium. CONCLUSION: Three-dimensional DSA allows acquisition of high-quality 3D images of cerebral arteries and also allows observation and analysis from multiple directions to determine the appropriate working projection for embolization. Three-dimensional DSA is essential for optimal diagnosis and embolization of cerebral aneurysms and can reduce the number of exposures.

Adolescent↗

PubMed2002

A case of adult influenza A virus-associated encephalitis: magnetic resonance imaging findings.

A 27-year-old man presented with fever, convulsive seizure, and sudden impairment of consciousness. Magnetic resonance imaging (MRI) abnormalities were found in the bilateral thalami, including the brain stem and white matter. The possibility of a previous influenza A virus infection was considered, and cerebrospinal fluid cells and interleukin-6 were elevated. The MRI findings closely resembled those found in cases of childhood acute necrotizing encephalopathy (ANE). The present case suggests that adult influenza A virus-associated encephalitis/encephalopathy or ANE can occur during winter influenza epidemics.

Adult↗

PubMedDate not supplied

Rotational three-dimensional cholangiography--initial clinical experience.

PURPOSE: The purpose of this study was to evaluate the feasibility and image quality of a novel biliary imaging technique that obtains 3D cholangiography image sets by infusing contrast material through a PTC-drainage tube, using 3D-digital subtraction angiography (DSA). METHODS: We applied this technique to seven patients suspected of having biliary disease. All patients underwent PTCD because of obstructive jaundice. Contrast material was introduced through the drainage tube, and the raw data were then transferred automatically to a workstation. Approximately 3 minutes of user time was required to generate the 3D images following image acquisition. RESULTS: Three-dimensional cholangiography was obtained in all patients who underwent 3D-DSA examination. Acceptable quality 3D-DSA cholangiograms were generated in six of the seven patients. CONCLUSION: We emphasize that our new technique may help during surgery as an aid to understanding anatomical structures in the biliary system.

Aged↗

PubMedDate not supplied

Distal-tip shape-consistency testing of steam-shaped microcatheters suitable for cerebral aneurysm coil placement.

BACKGROUND AND PURPOSE: Although the selection of microcatheter for endovascular aneurysmal treatment is one important factor in patient outcome, the use of steam shaping for achieving safe entry and stability during coil placement has not, to our knowledge, been systematically evaluated. The goal of this study was to compare the durability of distal microcatheter steam shaping in five different catheters with typical intraprocedural stresses that are similar to those encountered during aneurysm coil placement. METHODS: Distal tips of microcatheters were shaped into a 90 degrees turn with distal straight-segment lengths of 3, 5, or 7 mm by using steam, performed according to the instructions for use included with each catheter. In a water bath kept at body temperature, the changes in catheter tip angle were recorded and measured following microcatheter insertion into a guiding catheter, microguidewire insertion through the microcatheter, and Guglielmi detachable coil (GDC) placement through the microcatheter. RESULTS: The degree of distal microcatheter straightening with typical intraprocedural manipulations was more pronounced on braided microcatheters and on microcatheters with 3- or 5-mm distal-shaped segments. The degree of spontaneous recovery of the initially steamed shape was more pronounced with nonbraided catheters. The most significant single variable contributing to straightening of a steam-shaped catheter tip was the effect of microguidewire insertion. The catheter-tip straightening effect encountered with inserting GDCs was less than that encountered with microguidewire insertion. We demonstrated that the decreased catheter-tip angle encountered with a large-magnitude straightening stress spontaneously recovered once the stress was removed or when it was reduced to a smaller magnitude stress. CONCLUSION: Our study shows that, although braided microcatheters are suitable for maintaining durable configurations when long distal-tip lengths are permissible, nonbraided microcatheters demonstrate the most durable distal-tip configurations when short distal-tip lengths are called for. This may be one of significant factors in catheter choice for endovascular treatment of aneurysm.

Catheterization↗

PubMedDate not supplied

Blood brain-barrier disruption of nonionic iodinated contrast medium following coil embolization of a ruptured intracerebral aneurysm.

Few reports of temporary disruption of the blood-brain barrier (BBB) following neurointerventional procedures, presumably caused by nonionic radiographic contrast medium (CM), exist in the literature. We described such a case in a 72-year-old man presenting with acute subarachnoid hemorrhage, who underwent coil embolization of a ruptured anterior communicating artery complex aneurysm. At the time of his follow-up CT examination, a large amount of iodine was found in the cerebrospinal fluid (CSF). Because of this experience, the iodine concentration in the CSF of five other patients who also underwent an intracranial endovascular procedure was measured. It was concluded that this increased iodine might have been caused by temporary leakage or breakdown of the BBB. Even if the total amount of CM may not be excessive, the disproportionately high concentration injected into a single vascular territory may pose a unique set of variables increasing the risk of BBB disruption.

Aged↗