PubMed Health⌕ Search

Biomedical subjects

Teiji Tominaga

Publications and source records attributed to Teiji Tominaga.

At least 19 recordsLinked to original sources
PubMed2004

Hydrocephalus due to cerebrospinal fluid overproduction by bilateral choroid plexus papillomas.

CASE REPORT: A 10-month-old boy, with congenital deafness and blindness associated with chromosomal deletion [46XY, del(13)(q32)], presented with intractable ascites 9 months after ventriculo-peritoneal shunting for congenital hydrocephalus. Revision of the ventriculo-atrial shunt resulted in shunt failure 1 month later. External ventricular drainage revealed cerebrospinal fluid (CSF) overproduction (2,000 ml/day). Magnetic resonance imaging showed marked lobular enlargement of the bilateral choroid plexuses extending from the trigone to the body and inferior horn of the lateral ventricle. Multi-staged resection was performed via bilateral temporo-occipital transcortical approaches, and CSF production significantly decreased to 100 ml/day postoperatively. Histological assessment of the villous surface suggested villous hyperplasia of the choroid plexus and thorough evaluation including the proximal portion of the lobular lesion near the attachment revealed choroid plexus papilloma. He was discharged after ventriculo-peritoneal shunting without additional neurological deficits except for hyperreflexia of the left extremities. CONCLUSION: CSF overproduction caused by bilateral choroid plexus papillomas can result in hydrocephalus. Radical resection of the bilateral ventricular lesions should be considered for this entity. Thorough evaluation of the surgical specimen is recommended because histological examination of only the lobular surface of the choroid plexus lesion may fail to identify choroid plexus neoplasm.

Cerebrospinal Fluid↗
PubMed2004

Experimental application of pulsed Ho:YAG laser-induced liquid jet as a novel rigid neuroendoscopic dissection device.

BACKGROUND AND OBJECTIVES: Although water jet technology has been considered as a feasible neuroendoscopic dissection methodology because of its ability to perform selective tissue dissection without thermal damage, problems associated with continuous use of water and the ensuing fountain-effect-with catapulting of the tissue-could make water jets unsuitable for endoscopic use, in terms of safety and ease of handling. Therefore, the authors experimented with minimization of water usage during the application of a pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser-induced liquid jet (LILJ), while assuring the dissection quality and the controllability of a conventional water jet dissection device. We have developed the LILJ generator for use as a rigid neuroendoscope, discerned its mechanical behavior, and evaluated its dissection ability using the cadaveric rabbit ventricular wall. STUDY DESIGN/MATERIALS AND METHODS: The LILJ generator is incorporated into the tip of a stainless steel tube (length: 22 cm; internal diameter: 1.0 mm; external diameter: 1.4 mm), so that the device can be inserted into a commercial, rigid neuroendoscope. Briefly, the LILJ is generated by irradiating an internally supplied water column within the stainless steel tube using the pulsed Ho:YAG laser (wave length: 2.1 microm, pulse duration time: 350 microseconds) and is then ejected through the metal nozzle (internal diameter: 100 microm). The Ho:YAG laser pulse energy is conveyed through optical quartz fiber (core diameter: 400 microm), while cold water (5 degrees C) is internally supplied at a rate of 40 ml/hour. The relationship between laser energy (range: 40-433 mJ/pulse), standoff distance (defined as the distance between the tip of the optical fiber and the nozzle end; range: 10-30 mm), and the velocity, shape, pressure, and average volume of the ejected jet were analyzed by means of high-speed camera, PVDF needle hydrophone, and digital scale. The quality of the dissection plane, the preservation of blood vessels, and the penetration depth were evaluated using five fresh cadaveric rabbit ventricular walls, under neuroendoscopic vision. RESULTS: Jet velocity (7.0-19.6 m/second) and pressure (0.07-0.28 MPa) could be controlled by varying the laser energy, which determined the penetration depth in the cadaveric rabbit ventricular wall (0.07-1.30 mm/shot). The latter could be cut into desirable shapes-without thermal effects-under clear neuroendoscopic vision. The average volume of a single ejected jet could be confined to 0.42-1.52 microl/shot, and there was no accompanying generation of shock waves. Histological specimens revealed a sharp dissection plane and demonstrated that blood vessels of diameter over 100 microm could be preserved, without thermal damage. CONCLUSIONS: The present pulsed LILJ system holds promise as a safe and reliable dissection device for deployment in a rigid neuroendoscope.

Animals↗
PubMed2004

Dissection of the superior cerebellar artery: a report of two cases and review of the literature.

Arterial dissections frequently involve the main trunk of the posterior circulation and are recognised as an important cause of stroke in young individuals. However, dissection confined to cerebellar arteries is rare. We encountered two patients with superior cerebellar artery (SCA) dissection. A 37-year-old man presented with dysarthria, right limb ataxia, and severe headache. Magnetic resonance imaging revealed cerebellar infarction in the right SCA territory. Angiography demonstrated stenosis and fusiform dilation of the SCA in the anterior pontine segment. Recovery with antiplatelet treatment was nearly complete. A 45-year-old man was admitted with decreased consciousness after sudden onset of headache. Computed tomography demonstrated subarachnoid haemorrhage with hydrocephalus. Angiography revealed fusiform dilation of the left SCA in the anterior pontine segment. After ventricular drainage, endovascular embolisation was performed without ischaemic complications. The patient's condition improved sufficiently to return to daily life. In our search only four reported cases involved the SCA. Clinical manifestation and treatment for patients with cerebellar arterial dissections are discussed.

Adult↗
PubMed2004

Intractable vomiting as an early clinical symptom of cerebrospinal fluid seeding to the fourth ventricle in patients with high-grade astrocytoma.

OBJECT: Cerebrospinal fluid (CSF) seeing of high-grade astrocytoma is common, but the early clinical symptoms are not well characterized. Here, we report five patients with disseminated high-grade astrocytoma in the fourth ventricle region who presented with intractable vomiting prior to the detection of the metastatic deposits with enhancement. PATIENTS AND METHODS: From 1994 to 2000, 133 patients of high-grade astrocytoma were treated in our institute and were followed up until December 2002. Follow-up magnetic resonance (MR) imaging was performed in all patients every 2-3 months. The CSF seeding was defined as leptomeningeal enhancement. Signs and symptoms of CSF seeding were checked at the monthly outpatient examination. RESULTS: Among them, 5 patients aged from 27 to 58 years (mean 43.8 years) with one anaplastic astrocytoma and four glioblastomas showed intractable vomiting without signs of high intracranial pressure as evaluated by MR imaging or ocular fundus examination prior to the detection of the fourth ventricle dissemination. Fourth ventricle dissemination appeared 1-3 months after vomiting in five patients. One patient with glioblastoma received gamma knife radiotherapy for a fourth ventricle lesion appearing as a high intensity area on T2-weighted imaging before the appearance of the enhanced nodule, and this lesion was cured. Four patients died of progression of the fourth ventricle lesion. CONCLUSION: Intractable vomiting may be an early clinical symptom of CSF seeding to the fourth ventricle in patients with high-grade astrocytoma. Early detection and immediate radiotherapy for this lesion are recommended to control fourth ventricle dissemination.

Adult↗
PubMed2004

Comparison of magnetoencephalographic spikes with and without concurrent electroencephalographic spikes in extratemporal epilepsy.

Interictal spikes in patients with epilepsy may be detected by either electroencephalography (EEG) (E-spikes) or magnetoencephalography (MEG) (M-spikes), or both MEG and EEG (E/M-spikes). Localization and amplitude were compared between E/M-spikes and M-spikes in 7 adult patients with extratemporal epilepsy to evaluate the clinical significance of MEG spikes. MEG and EEG were simultaneously measured using a helmet-shaped MEG system with planar-type gradiometers and scalp electrodes of the international 10-20 system. Sources of E/M-spikes and M-spikes were estimated by an equivalent current dipole (ECD) model for MEG at peak latency. Each subject showed 9 to 20 (mean 13.4) E/M-spikes and 9 to 31 (mean 16.3) M-spikes. No subjects showed significant differences in the ECD locations between E/M- and M-spikes. ECD moments of the E/M-spikes were significantly larger in 2 patients and not significantly different in the other 5 patients. The similar localizations of E/M-spikes and M-spikes suggest that combination of MEG and EEG is useful to detect more interictal spikes in patients with extratemporal epilepsy. The smaller tendency of ECD amplitude of the M-spikes than E/M-spikes suggests that scalp EEG may overlook small tangential spikes due to background brain noise. Localization value of M-spikes is clinically equivalent to that of E/M-spikes.

Adolescent↗
PubMed2004

Spontaneous regression of a primary cerebral tumor following vasospasm caused by subarachnoid hemorrhage due to rupture of an intracranial aneurysm--case report.

A 40-year-old man demonstrated spontaneous regression of a malignant glioma following vasospasm caused by subarachnoid hemorrhage due to rupture of an intracranial aneurysm. The patient had been treated under a diagnosis of malignant glioma for 5 years. He presented with a ruptured aneurysm manifesting as subarachnoid hemorrhage. Single photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine and diffusion-weighted magnetic resonance (MR) imaging revealed severe flow reduction due to vasospasm in the bilateral temporoparietal cortical regions, including the tumor. MR imaging performed 5 months later showed marked tumor regression. The present case suggests that treatment targeting angiogenesis of malignant gliomas may be effective as a part of multimodality treatment.

Adult↗
PubMed2004

Intramedullary spinal tuberculoma--case report.

A healthy 33-year-old man presented with an intramedullary tuberculoma of the thoracic spinal cord manifesting as a 2-month history of progressive paraparesis and sphincter dysfunction. Magnetic resonance imaging showed ring enhancement of the intramedullary thoracic lesion with perifocal edema. General physical examination was unremarkable with no signs of inflammation except for a positive finding by the tuberculin skin test. Total resection of the intramedullary mass was performed through a posterior myelotomy following T11-12 laminectomy. Histological examination revealed a granulomatous lesion that contained Langhans giant cells, inflammatory cells, and caseating necrosis. Acid-fast bacilli staining of the specimens was positive, and cultures grew Mycobacterium tuberculosis. Postoperatively, the paraparesis and sphincter dysfunction improved sufficiently for the patient to return to his ordinary activities. Intramedullary spinal tuberculoma is rare, but must be considered in the differential diagnosis of spinal cord compression.

Adult↗
PubMed2004

The role of sigma-receptors in levodopa-induced dyskinesia in patients with advanced Parkinson disease: a positron emission tomography study.

OBJECT: Levodopa-induced dyskinesia (LID) in patients with Parkinson disease (PD) mimics acute dystonic reactions induced by antipsychotic agents, possibly mediated by sigma-receptors; however, there are few reports in which the relationship between sigma-receptors and LID in advanced PD is investigated. The binding potential of cerebellar sigma-receptors before and after a pallidal surgery for dyskinesia in patients with advanced PD is assessed. METHODS: Six patients with advanced PD (male/female ratio 3:3, age 56.7 +/- 9.8 years) underwent stereotactic pallidal surgery (two posteroventral pallidotomy procedures and four deep brain stimulation of the globus pallidus internus, including one bilateral case). Clinical features of patients with PD were assessed using Hoehn and Yahr (H & Y) stages, the Unified Parkinson's Disease Rating Scale (UPDRS), and the Schwab and England Activities of Daily Life Scale (S & E). The LID was evaluated by LID severity score. The binding potential of cerebellar sigma-receptors was determined before and after the surgery by 11C-nemonapride positron emission tomoraphy, a specific radioligand for sigma-receptors in the cerebellum. All clinical scores, especially the LID severity score, were dramatically improved after the surgery (p < 0.05). Preoperatively, contralateral cerebellar binding potential was significantly elevated (p < 0.01), and it was reduced after the surgery, but it was still higher than that of healthy volunteers (p < 0.05). The ipsilateral cerebellar binding potential remained unchanged after the surgery. The level of binding potential did not correlate with H & Y stage, UPDRS, or S & E score, but a strong positive correlation was seen between the binding potential and the preoperative LID severity score when the patients were receiving medication (r = 0.893, p < 0.05). CONCLUSIONS: Cerebellar sigma-receptors may potentially involve the genesis of LID in advanced PD.

Aged↗
PubMed2004

Pulsed holmium:yttrium-aluminum-garnet laser-induced liquid jet as a novel dissection device in neuroendoscopic surgery.

OBJECT: A pressure-driven continuous jet of water has been reported to be a feasible tool for neuroendoscopic dissection owing to its superiority at selective tissue dissection in the absence of thermal effects. With respect to a safe, accurate dissection, however, continuous water flow may not be suitable for intraventricular use. The authors performed experiments aimed at solving problems associated with continuous flow by using a pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser-induced liquid jet (LILJ). They present this candidate neuroendoscopic LILJ dissection system, having examined its mechanical characteristics and evaluated its controllability both in a tissue phantom and in a rabbit cadaveric ventricle wall. METHODS: The LILJ generator was incorporated into the tip of a No. 4 French catheter so that the LILJ could be delivered via a neuroendoscope. Briefly, the LILJ was generated by irradiating an internally supplied column of physiological saline with a pulsed Ho:YAG laser (pulse duration time 350 microsec; laser energy 250-700 mJ/pulse) within a No. 4 French catheter (internal diameter 1 mm) and ejecting it from a metal nozzle (internal diameter 100 microm). The Ho:YAG laser energy pulses were conveyed by an optical fiber (core diameter 400 microm) at 3 Hz, whereas physiological saline (4 degrees C) was supplied at a rate of 40 ml/hour. The mechanical characteristics of the pulsed LILJ were investigated using high-speed photography and pressure measurements; thermal effects and controllability were analyzed using an artificial tissue model (10% gelatin of 1 mm thickness). Finally, the ventricle wall of a rabbit cadaver was dissected using the LILJ. Jet pressure increased in accordance with laser energy from 0.1 to 2 bar; this translated into a penetration depth of 0.08 to 0.9 mm per shot in the ventricle wall of the rabbit cadaver. The gelatin phantom could be cut into the desired shape without significant thermal effects and in the intended manner, with a good surgical view. CONCLUSIONS: The present results show that the pulsed LILJ has the potential to become a safe and reliable dissecting method for endoscopic procedures.

Animals↗
PubMed2004

Computational simulation of therapeutic parent artery occlusion to treat giant vertebrobasilar aneurysm.

We applied computational fluid dynamics (CFD) analysis to assess 3D digital subtraction angiography findings in a patient with a giant vertebrobasilar aneurysm to simulate and compare the consequences of left and right vertebral artery occlusion. The balloon occlusion test suggested that occlusion of the right vertebral artery is the better way to treat this patient's aneurysm from the point of view of aneurysmal thrombosis and isolation from the circulation. The computer simulation supported this conclusion, at the same time indicating that from the point of view of pressure distribution on the wall of the aneurysm, the right vertebral occlusion may be also accompanied by an undesirable effect. A high-pressure area on the aneurysm wall in systole was revealed. This high pressure potentially could lead to subsequent aneurysmal growth, which indeed occurred, as was revealed by a follow-up examination 6 months later. This study is a good example of possible future applications of CFD in patients with cerebrovascular disease before therapeutic intervention.

Aged↗
PubMed2004

[Clinical feature and surgical treatment of spontaneous spinal epidural hematoma].

We presented 10 patients of spontaneous spinal epidural hematoma (SSEH) who were surgically treated between July 1996 and June 2003. One male and 9 female patients whose ages ranged from 16 to 75 years (mean age is 60) enrolled in this study. All cases initially presented with severe back and radicular pain followed by sensory and motor dysfunction. Sphincter dysfunction was observed in 8 patients. Although three cases were initially suspected as cardiovascular diseases and two as cerebral stroke, all cases were successfully diagnosed with magnetic resonance imaging studies. The hematoma was located at the dorsal cervical levels in 3 cases, the dorsal cervicothoracic in 1, the dorsal thoracic in 4, the ventral thoracic in 1, and the ventral lumbosacral in 1. After surgical evacuation of the hematoma, neurological dysfunctions improved in all patients. In particular, surgical decompression was performed within 36 hours after onset in 5 cases suffering severe neurological dysfunction according to the Frankel Grading System. To obtain good prognosis for patients with SSEH, early diagnosis and immediate treatment are important.

Adolescent↗
PubMed2004

Computational replicas: anatomic reconstructions of cerebral vessels as volume numerical grids at three-dimensional angiography.

BACKGROUND AND PURPOSE: We present a relatively simple approach that physicians can use to reconstruct cerebral vessels as 3D numerical grids or computational replicas. The method accurately duplicates their geometry to provide computer simulations of their blood flow. METHODS: Initial images were obtained by using any medical imaging technique, such as MR angiography, CT angiography, or 3D digital subtraction angiography. The data were collected in DICOM format and converted by a DICOM reader into a 3D gray-scale raster image. The image was then processed by using commercial visualization and mesh generation software, which allowed extraction of the luminal surface of the blood vessel (by using the isosurfacing technique). The subsequent final output was an unstructured tetrahedral grid that can be directly used for detailed analysis of cerebral vascular geometry for patient-specific simulations of blood flow. RESULTS: Four examples of grid reconstruction and blood flow simulation for patients with ruptured aneurysms were validated with angiographic and operative findings. The ruptured areas were correlated with areas of high fluid-induced wall-shear stress. CONCLUSION: This approach promises to be a practical tool for planning treatment and follow-up of patients after neurosurgical or endovascular interventions with 3D angiography. The proposed commercial packages or conceptually similar ones seem to be relatively simple and suitable for direct use by neurosurgeons or neuroradiologists.

Aneurysm, Ruptured↗
PubMed2003

Cervical cord compression with myelopathy caused by bilateral persistence of the first intersegmental arteries: case report.

OBJECTIVE AND IMPORTANCE: Cervical myelopathy induced by vascular compression is rare. We report a case caused by bilateral persistence of the first intersegmental arteries (a vertebral artery anomaly). Myelopathy was successfully treated with vascular decompression. CLINICAL PRESENTATION: A 66-year-old woman presented with gradually worsening paroxysmal neck and arm pain. Magnetic resonance imaging and angiography demonstrated anomalous intradural courses of both vertebral arteries, compressing the dorsal aspect of the cervical spinal cord. INTERVENTION: Microvascular decompression was performed with transposition of the arteries, followed by anchoring of the arteries to the dorsolateral dura mater with Gore-Tex bands (W.L. Gore & Associates, Inc., Flagstaff, AZ). CONCLUSION: The pain disappeared promptly after surgery. Surgical decompression, with anchoring of an anomalous vertebral artery to the dura, can relieve pain and other symptoms resulting from vascular cord compression.

Aged↗
PubMed2003

Selective loss of Purkinje cells in transverse and sigmoid dural arteriovenous fistulas. Report of two cases.

The histological changes that occur in brain tissue have rarely been documented in patients with dural arteriovenous fistulas (AVFs). In this study the authors report on two patients with dural AVFs in the transverse-sigmoid sinus who presented with subarachnoid hemorrhage or progressive dementia. Histological studies of the cerebellar cortices showed a selective loss of Purkinje cells, indicating an ischemic insult caused by venous hypertension. Admission N-isopropyl-p-123I-iodoamphetamine single-photon emission computerized tomography scans demonstrated a decrease in cerebral blood flow, including flow through the cerebellum. Venous hypertension caused by transverse-sigmoid sinus dural AVFs provokes an ischemic condition severe enough to cause selective neuronal damage in the cerebellum.

Aged↗
PubMed2003

[A case of hyperemia during arteriovenous malformation surgery controlled with beta-blocker and jugular bulb oxygen saturation (SjO2) monitoring].

The authors report a case of hyperemic complications during arteriovenous malformation (AVM) surgery controlled with beta-blocker. A 25-year-old male was anesthetized with propofol-fentanyl under jugular venous bulb oxygen saturation (SjO2) monitoring. Just after the total removal of AVM, SjO2 and blood pressure increased suddenly and brain swelling occurred. On the diagnosis of hyperemia of the brain, hyperventilation and controlled hypotension with nicardipine, diltiazem and sodium nitroprusside were started, but they were not effective. Thereafter, we injected a beta-blocker (propranolol, 0.2 mg) intravenously, resulting in the decrease in blood pressure and the disappearance of the brain swelling. SjO2 monitoring supports the safe management of postresection hyperemia, and beta-blocker can be useful against hyperemic complications during and after AVM surgery.

Adrenergic beta-Antagonists↗