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R Shirane

Publications and source records attributed to R Shirane.

At least 73 records · Page 4Linked to original sources
PubMed1996

Congenital absence and aberrant course of the internal carotid artery.

We retrospectively reviewed the imaging features of an aberrant course of the internal carotid artery (ICA) in one patient and its unilateral absence in four. Absence of the ICA was initially detected by MRI and MR angiography in both patients who underwent these examinations. CT revealed an abnormal or absent carotid canal in all cases. Radiological diagnosis by MRI and MR angiography could play an important role in the diagnosis.

Adult↗
PubMed1996

Surgical treatment of a sacral nerve root cyst with intermittent claudication in an 85-year-old patient: case report.

The following presents a case of an 85-year-old woman with intermittent claudication of a sacral nerve root cyst. The cyst wall was incised and oversewn while preserving the surrounding nerve fibers by microscopic procedures. All symptoms were eliminated following the operation. The syndrome of intermittent claudication may possibly arise while walking from the transient influx of cerebrospinal fluid into a cyst in a relatively narrow sacral canal. The present case may indicate that a sacral nerve root cyst is curable even in aged patients through thorough evaluation and management.

Age Factors↗
PubMed1995

Clinical and angiographic follow-up of childhood-onset moyamoya disease.

To clarify the differences between childhood-onset moyamoya disease and that with onset in adulthood, we studied the clinical course and angiographic findings of adult patients (over 20 years of age) with moyamoya disease of childhood onset (up to 15 years of age). The clinical course in 25 patients could be assessed. The follow-up period was 5-27 years. Neurological deficits were noted in 11/23 and mental disorders in 9/21. In all except one, the illness had started before the age of 7 years. Neither neurological nor mental condition changed during or after adolescence (15-20 years of age). Two patients died of intracranial hemorrhage. The disease progressed in angiographic stage until adolescence, but had stabilized or almost stabilized by the age of 20 years. This study indicates that moyamoya disease with onset in childhood carries high morbidity and mortality. The disease advances in angiographic stage between childhood and adolescence, but stabilizes or almost stabilizes between adolescence and adulthood.

Adolescent↗
PubMed1994

Primary culture of human leptomeningeal cells in serum-free medium.

Human leptomeningeal (LM) cells were grown in serum-free medium supplemented with insulin, transferrin and bovine serum albumin. The cultured cells maintained the polygonal morphology characteristic of leptomeningeal cells. Electronmicroscopic and immunofluorescence examinations revealed interdigitation of cell membranes, invagination of cytoplasm into the nucleus, specialized intercellular junctions and the presence of cytokeratin. These characteristics are consistent with previous reports characterizing LM cells. This serum-free culture system may facilitate the in vitro study of the leptomeninges.

Arachnoid↗
PubMed1993

Early and delayed SPECT images of extracerebral fluid collection in infants using 123I-N-isopropyl-p-iodoamphetamine.

Cerebral blood flow in seven infants with extracerebral fluid collections was investigated using single photon emission computed tomography (SPECT) with 123I-N-isopropyl-p-iodoamphetamine. Early and delayed SPECT imaging was carried out. Areas of hypoperfusion were observed in five cases. The watershed zone of the major cerebral arteries or the territory of the anterior cerebral arteries were common areas of low perfusion. The hypoperfusion area was redistributed in two cases with intracranial hypertension. Subduroperitoneal shunts produced improvement of clinical symptoms in these cases. Hypoperfusion without redistribution was observed in three patients. In these areas, permanent tissue damage caused by a primary disease existed. Normal circulation patterns were observed in two patients. They showed normal development and follow-up CT revealed a decrease in the size of the extracerebral fluid collection. Measurement of regional cerebral blood flow may be helpful in considering surgical indications and in following up extracerebral fluid collection in infants.

Asphyxia Neonatorum↗
PubMed1993

Tethered cord syndrome associated with male Turner's syndrome.

Tethered cord syndrome associated with Turner's syndrome in an 8-year-old boy is reported. Complicated mesodermal anomalies were observed from birth: a ventricular septal defect, hydronephrosis, agenesis of the sacrum, hypospadias, and anal atresia. Male external genitalia and a 45XO/46XY mosaic chromosome pattern were recognized, and a diagnosis of male Turner's syndrome was made. In the course of development, aggravation of a neurogenic bladder and a gait disturbance appeared. Low spinal conus and thickened filum were observed on MRI, and an operation of untethering was performed. The possible genesis of the thickened filum in systemic mesodermal anomalies of Turner's syndrome is discussed.

Child↗
PubMed1993

Evaluation of tethered cord syndrome associated with anorectal malformations.

The clinical courses of four patients with occult spinal dysraphism who were also found to have anorectal malformations and tethered cord syndrome are evaluated in this report. These patients were among 27 patients with occult spinal dysraphism treated in the Division of Neurosurgery of Tohoku University School of Medicine during the last 3 years. All four patients experienced urinary disturbances early in life, and initially, these disturbances were considered to be caused by urogenital malformations. As a result, treatments were delayed. Only one patient with male Turner's syndrome exhibited mental retardation. Other symptoms, such as sensory disturbance and pain in the lower extremities, became apparent from complaints by the patients without atresia ani. When surgery was performed earlier in our patients with occult spinal dysraphism, the outcome was better. We believe in early surgery for tethered cord syndrome, although there is no consensus for the timing of this surgery. Unfortunately, the diagnosis of tethered cord syndrome was delayed in our four patients. However, because occult spinal dysraphism and anorectal malformations seem to be closely related, the presence of anorectal malformations may result in an earlier diagnosis of tethered cord syndrome.

Anus, Imperforate↗
PubMed1993

[A case of tectal glioma].

A case of tectal glioma with mild choked disc is reported. An 11-year-old boy was admitted to our hospital because of visual disturbance and choked disc. Neurologically, the patient had nothing but choked disc. Magnetic resonance imaging (1.5T) was performed. Relative T1 weighted image showed a lesion of low signal intensity, and T2 weighted image showed high intensity, about 1.0 x 1.0 cm in size, at the pineal region. The sagittal view showed a mass at the tectum, and stenosis of the aqueduct. It was diagnosed as tectal glioma. Left occipital craniotomy was performed and the tumor was removed subtotally. Histological examination demonstrated a fibrillary astrocytoma. Radiochemotherapy was performed postoperatively. Tectal glioma is very rare. The differential diagnosis from germ cell tumor or pineal cyst is essential for treatment. The authors performed an operation in order to remove the tumor and determine the course of treatment.

Brain Neoplasms↗
PubMed1992

Angiographic findings of ischemic stroke in children.

A cooperative study was undertaken in the Tohoku district of Japan to investigate the relatively rare phenomenon of cerebral infarction in children. The purpose of the present paper is to describe the cerebral angiographic findings in 48 children whose ischemic lesions were confirmed by CT scan. The majority of lesions were considered to be idiopathic. The areas of cerebral infarction appearing in the CT scans were located in the territory of the middle cerebral artery including the basal ganglia. Angiographical abnormalities were observed in 40 patients (83%). The majority occurred in the supraclinoid portion of the internal carotid artery and in the cisternal portion of the middle and anterior cerebral arteries. Multiple lesions, such as in the C1, A1, and M1 or the C1, M1, and M2 segments were observed in 22 cases. These lesions generally appeared in continuation; no bilateral intracranial lesions were observed. Repeated angiography was performed in 22 cases, and in 55% of these some recovery of the lesions was seen.

Cerebral Angiography↗
PubMed1992

Cerebral blood flow and oxygen metabolism in infants with hydrocephalus.

In this study, regional cerebral blood flow (rCBF) and the cerebral metabolic rate of oxygen (rCMRO2) were measured using positron emission tomography (PET) with oxygen-15 radiopharmaceuticals to clarify the pathophysiology of ventriculomegaly in the developing brain. Four hydrocephalic infants without severe neurological deficit were studied. Hypoperfusion was observed in the frontal, parietal, and visual association cortices which surrounded dilated anterior or posterior horns of the lateral ventricle. Lower rCMRO2 values than adult rates were observed in all cases. In the infants with markedly enlarged anterior or posterior horns, the surrounding cortices showed relatively lower rCMRO2 values with the fall of rCBF. Postoperative studies were performed in two infants. rCMRO2 increased in every region after ventriculoperitoneal shunting, but little change was observed in rCBF. These results indicate that metabolic deterioration occurs in the developing brain with hydrocephalus.

Blood Volume↗
PubMed1992

Congenital cerebral venous dysgenesis. Decreased cerebral blood flow in deep cerebral regions revealed by SPECT.

This report describes a rare case of primary cerebral venous dysgenesis in a 3-year-old child with development retardation. Angiography resulted in nonvisualization not only of deep cerebral veins but also of superficial cerebral veins. In computed tomography and in magnetic resonance imaging the collateral venous circulation appeared as a strange configuration in the pineal region. Single photon emission computed tomography using N-isopropyl-p-[I-123]-iodoamphetamine revealed decreased regional cerebral blood flow in the basal ganglia and thalamus, but cerebral infarction was not detected in the area. These features indicate that in this case, dysgenesis of deep cerebral veins, which probably occurred during prenatal life, had caused hypoperfusion in the deep cerebral regions.

Carotid Arteries↗
PubMed1992

Repositioning of the tortuous vertebrobasilar artery for trigeminal neuralgia: a technical note.

A patient with trigeminal neuralgia caused by a tortuous vertebrobasilar artery is reported. To obtain safe and certain neurovascular decompression of the trigeminal nerve, the tortuous vertebrobasilar artery was repositioned by pulling it toward the dura mater of the clivus using a synthetic vascular slip. The authors describe the technique of repositioning of the tortuous vertebrobasilar artery and its usefulness.

Basilar Artery↗
PubMed1992

Effect of mannitol on local cerebral blood flow after temporary complete cerebral ischemia in rats.

The effects of pretreatment with mannitol on local cerebral blood flow (CBF) after permanent or temporary global cerebral ischemia were evaluated with 14C-iodoantipyrine autoradiography in rats under halothane-N2O endotracheal anesthesia. Blood pressure, pulse rate, arterial blood gas levels, and electroencephalographic (EEG) tracings were monitored throughout the experiments. After permanent occlusion of the basilar artery and both external carotid and pterygopalatine arteries, severe global ischemia was induced by permanent occlusion of the common carotid arteries (CCA's) or by a 30-minute temporary CCA occlusion followed by 5 minutes of reperfusion. Intravenous mannitol (25%, 1 gm/kg) or saline solution was administered 5 minutes before occlusion of the CCA's. Cerebral blood flow was measured in 24 anatomical regions. The EEG tracings flattened within 2 to 3 minutes after the onset of ischemia, and no recovery was observed during reperfusion. In the mannitol-treated rats and the saline-treated controls, autoradiographic studies after permanent occlusion showed no CBF in the forebrain or cerebellum, although brain-stem and spinal cord CBF values were normal. After 5 minutes of reperfusion, CBF in the cortex, basal ganglia, and white matter was 100% to 200% higher in mannitol-treated rats and 50% to 100% higher in saline-injected rats than in the nonischemic anesthetized control group. Heterogeneously distributed areas of no-reflow were seen in all saline-injected rats but were observed in none of the mannitol-treated rats. Pretreatment with mannitol prevented postischemic obstruction of the microcirculation during 5 minutes of recirculation after 30 minutes of severe temporary ischemia, but the EEG signals did not recover. Further studies of the functional and morphological responses to longer periods of postischemic recirculation are needed to verify the extent to which these mannitol-induced effects are protective.

Animals↗
PubMed1992

[Anterior sacral meningocele associated with tethered cord syndrome].

A case of anterior sacral meningocele associated with tethered cord syndrome is reported. A 5-year-old boy was admitted for urinary and fecal incontinence which had persisted since his birth. Abdominal MRI and sacral CT showed a presacral cystic mass communicating with the spinal dural sac through a neck traversing a sacral bony defect and tethered spinal conus. Neurological examination showed that the patient had a neurogenic bladder, atrophy of the legs and anesthesia below the S3 level. Operative finding revealed a thickened filum terminale attached to the wall of the presacral meningocele. Agenesis of the nerve root below the S2 level was identified, and no neural elements entered into the sac. Untethering was performed. Postoperative course was uneventful and the patient is doing well with his neurogenic bladder gradually improving.

Child, Preschool↗
PubMed1992

[A case of diastematomyelia with meningomyelocele].

A case of diastematomyelia with meningomyelocele is presented here. The patient was a newly born infant with a soft tumor in the lumbo-sacral region. The lower extremities were not paretic, but anal reflex was negative. A plain X-ray and a CT scan of the spine showed a bone spur at L3, 4. An MRI showed a longitudinal slit in the spinal conus. The removal of the septum and repair of the cele was carried out. The operative view showed a bony septum which divided the spinal conus into two parts and nerves had spread out on the cele wall. After removal of the septum, the tethered cord was released. The postoperative condition remained stable. The reason for the occurrence of a combined case of diastematomyelia with meningomyelocele is not clear. We presume that abnormality of the mesoderm at the embryonic stage may have an effect on this sort of disorder.

Humans↗
PubMed1991

A new method for producing temporary complete cerebral ischemia in rats.

A new model of temporary complete cerebral ischemia was developed and tested in 64 rats. With use of microsurgical techniques, both pterygopalatine and external carotid arteries were occluded and the basilar artery was coagulated to reduce potential collateral CBF during ischemia. After this preliminary five-vessel occlusion, temporary global ischemia was induced by occluding the common carotid arteries (CCAs) with microclips. To validate the method, CBF was measured autoradiographically in 24 anatomical regions at death after 5 min of ischemia or after 15 min of ischemia followed by 5 min of reperfusion. Mean arterial blood pressure and arterial blood gases remained stable under controlled endotracheal ventilation and anesthesia (halothane, 70% N2O, and 30% O2) throughout the CBF experiments, except for a 10-15% increase in mean arterial blood pressure for 1-5 min after bilateral CCA occlusion. After the initial five-vessel occlusion, the EEG did not change, and local CBF levels were comparable to those in anesthetized non-surgical controls. When the CCAs were occluded, the EEG flattened rapidly; after 5 min of ischemia, autoradiography showed no detectable blood flow in the forebrain and cerebellum. The local CBF levels measured after 15 min of temporary global ischemia and 5 min of reperfusion demonstrated relatively homogeneous postischemic hyperperfusion; only two of eight rats had several 1- to 3-mm areas of no-reflow. Survival studies showed increasing motor impairment after 10, 15, 30, and 60 min of temporary CCA occlusion. Ischemic neuronal damage was observed histologically in the hippocampus and basal ganglia 24 h after 10 min of temporary ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Clinical survey of ischemic cerebrovascular disease in children in a district of Japan.

Ischemic cerebrovascular disease in children is relatively rare. To clarify the clinical features of ischemic stroke occurring in infants and children, we evaluated 54 cases of cerebral infarction, excluding cases of moyamoya disease, in patients less than 16 years old at 24 clinics in the Tohoku (northeast) district of Japan. We observed two incidence peaks, one in little children and the other in junior high school students. Infection and minor head trauma were more frequently seen prior to ischemic strokes than was heart disease. The middle cerebral artery region, including the basal ganglia, was most commonly affected (49 patients, 91%) on computed tomograms. Angiography was performed in 48 patients (89%) and showed various types of occlusive lesions, mostly affecting the middle cerebral artery. Hemiparesis was the most common form of disability following ischemic strokes (48 patients, 89%). Surgical treatment was carried out in seven patients (13%). The clinical course of these cases showed that the recovery of children after a stroke tends to be better than that of adults, but that permanent disabilities, such as hemiparesis or mental retardation, occur commonly. Further investigation of juvenile cerebrovascular disease is important to prevent ischemic strokes in children.

Adolescent↗