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Biomedical subjects

K Yada

Publications and source records attributed to K Yada.

At least 55 records · Page 3Linked to original sources
PubMed1993

Correlation between intravascular pressure and risk of hemorrhage due to arteriovenous malformations.

The correlation between intraoperative pressure levels measured in the feeding arteries and in the draining veins, and the risk of hemorrhage from arteriovenous malformations (AVMs) is discussed. Feeding artery pressure (FAP) was significantly higher in AVMs with hemorrhage (57 +/- 11 mmHg) than in AVMs without hemorrhage (38 +/- 4), and draining vein pressure (DVP) in the former (24 +/- 5) was significantly higher than that in the latter (13 +/- 5). FAP and DVP were inversely related to the number of draining veins and size of the AVMs. The present study suggests that a high FAP and a high DVP may contribute to the development of hemorrhage from AVMs, and supports previous reports that small AVMs and AVMs with only one draining vein are susceptible to hemorrhage.

Blood Pressure↗
PubMed1993

Radical removal of craniopharyngioma: a long-term follow-up.

Radical removal of craniopharyngiomas was attempted as the primary treatment in 12 adult and six child patients. No postoperative radiotherapy was given to patients undergoing total removal, while those undergoing subtotal removal received 50-60 Gy. Overall evaluation showed 15 cases of total removal and three of subtotal removal. One patient died of septicemia 2 months postoperatively and another developed a recurrent tumor which was removed totally at a second operation. The mean follow-up period was 7 years. The quality of life was "excellent" in 10 patients, "good" in five, and "fair" in two. Visual losses were minimized and endocrinological disturbances treated medically. These satisfactory results indicate that radical surgical removal is the first choice for treatment of craniopharyngioma irrespective of the age of patients.

Adolescent↗
PubMed1993

Invasive meningiomas in relation to high proliferating potential.

We conducted a study to investigate whether an association exists among histologic findings, labeling index determined by the labeling index (LI) of proliferating cell nuclear antigen (PCNA) and recurrence in a population of 30 meningioma patients. All of 6 patients (invasive meningioma) with brain invasion had a PCNA LI in excess of 5%. Recurrence was found in 4 of these patients. In 24 patients who did not have brain invasion, PCNA LI was 4% or less and only 1 case had recurrence. Recurrence occurred in 3 of 25 patients who underwent macroscopic total resection and all of these 3 cases had brain invasion and a PCNA LI in excess of 5%. The findings of this study indicated the existence of a close correlation between peripheral invasiveness of meningioma and its biological behavior.

Adolescent↗
PubMed1993

Origin of craniopharyngioma: an electron microscopic study.

To investigate the possibility that the two subtypes of craniopharyngioma, adamantinous type and squamous papillary type, are tumors arising from different origins, the authors conducted an electron microscopic study in 10 cases of craniopharyngioma. Light microscopic study revealed distinct differences between the two subtypes, but their ultrastructure was fundamentally similar. In this report, the authors propose an explanation of the origin of these subtypes to account for the findings.

Adolescent↗
PubMed1993

[Brain metastasis of testicular yolk sac tumor with massive hemorrhage: case report].

A rare case of yolk sac tumor of the testis which metastasized to the brain parenchyma with repeated intra-tumoral hemorrhage is reported. The patient was a 38 year-old-man admitted to the Department of Urology with the chief complaint of painless swelling of the left testis for a period of one year. He underwent orchiectomy with highly suspected malignancy, because chest X-ray examination demonstrated metastatic coin lesions. Pathological examination of the operated specimen showed typical yolk sac tumor of the testis. Postoperative clinical course was uneventful. However, on the 4th postoperative day, the patient suddenly fell into a coma with left hemiplegia and dilated right pupil. CT scan demonstrated an intra-parenchymal hematoma in the right parietal lobe. Emergency craniotomy with evacuation of the hematoma clot was performed. Histological examination of the hematoma clot showed the same histology (yolk sac tumor) as found in the operative specimens of the left testis. After regaining full consciousness, chemotherapy (PEB and PVB) was started. It was effective to reduce the high serum AFP level and the size of the metastatic coin lesions in the lung. However, it was not effective in preventing brain metastasis. He again relapsed into coma due to a newly-developed intra-tumoral hematoma with multiple brain metastasis and died 6 months after the orchiectomy. Yolk sac tumor of the testis is rare in adult Japanese and there is no previous report of its metastasis to the brain parenchyma with intratumoral hemorrhage. We have reviewed the previously reported cases and discussed the brain metastasis of this malignant urogenic tumor.

Adult↗
PubMed1993

[Selective cerebral perfusion and pharmacological cerebral protection in the patients with aortic arch aneurysm].

We have developed the protocol for selective cerebral perfusion (SCP) and pharmacological cerebral protection, and used it successfully in cases of aortic arch aneurysm. The subjects of the present study were 34 patients (28 males, 6 females) whose aortic arch aneurysm were surgically treated. Preoperative brain CT and brain scintigram showed high incidence of brain ischemia. However only 4 patients experienced a neurological episode. We conclude that our SCP technique and pharmacological cerebral protection are useful component to surgery of the aortic arch.

Adult↗
PubMed1993

[Clinical study in patients with perimesencephalic subarachnoid hemorrhage of unknown etiology].

We have recognized a characteristic distribution of cisternal blood in 10 (43%) of 23 patients with subarachnoid hemorrhage (SAH) of unknown etiology. On the initial CT examination undertaken within 48 hours of the onset, blood from 10 patients was found to be more densely distributed in the cisterns around the brainstem. In this study, clinical characteristics and CT findings in those 10 cases were carefully evaluated and the CT findings were compared to those of 416 patients with aneurysmal SAH (anterior circulation aneurysm 368 cases, posterior circulation aneurysm 48 cases). There were seven men and three women, with an age ranging from 39 to 64 years (average age, 50.6 years). The follow-up period ranged from 4 to 45 months (average follow-up period, 23 months). Neurological grade (WFNS) on admission was I in 9 cases and III in one case. None of the patients suffered symptomatic vasospasm, hydrocephalus or rebleeding. All the patients had favourable outcome and were categorized as good recovery according to the Glasgow Outcome Scale. In comparison with the cases of aneurysmal SAH, especially in comparison with 48 cases with SAH caused by posterior circulation aneurysm, 43 cases could be easily distinguished on CT. The other 5 cases showed almost the same pattern of SAH on CT, but 4 cases could be differentiated by either the extension of SAH to the interhemispheric fissure or the presence of intraventricular hemorrhage. Only one case could not be differentiated on CT. Thus SAH located only around the brainstem differs from aneurysmal SAH in its clinical course, and in distribution and severity of bleeding on CT. This could be recognized as a new clinical entity and could be called benign SAH.

Adult↗
PubMed1992

Primary intraosseous meningioma: case report.

A case of 72-year-old Japanese woman with a rare intraosseous meningioma is presented. The tumor was located in the right frontoparietal region, involving the coronal suture. The tumor was excised totally and the pathological diagnosis was meningioma. Similar cases reported in the past literature are reviewed and the possible histogenetic mechanism of the tumor is discussed.

Aged↗
PubMed1992

Bilateral homonymous hemianopsia due to tentorial herniation, with sparing of central vision: case report.

Cases of complete bilateral homonymous hemianopsia with sparing of central vision that are caused by bilateral tentorial herniation are extremely rare. We describe one such case resulting from severe head trauma, the first to be reported in which magnetic resonance images showed clear evidence of the responsible lesion. The causes of bilateral homonymous hemianopsia with sparing of central vision and the possible mechanisms whereby macular sparing may arise are discussed.

Adolescent↗
PubMed1992

Choroid plexus arteriovenous malformations.

Among 24 arteriovenous malformations (AVMs) involving the choroid plexus, 11 were plexal type AVMs predominantly located in the choroid plexus of the lateral ventricle, and 13 were parenchymal type AVMs mainly situated in the paraventricular cerebral parenchyma. 83% of all AVMs involved both the choroid plexus and the paraventricular cerebral parenchyma. Most cases presented with intracranial hemorrhage, particularly intraventricular hemorrhage. The most serious surgical problem was a small residual nidus unrecognized at the initial operation causing postoperative hemorrhage. Five parenchymal type AVMs presented residual niduses in the choroid plexus, causing death in two cases. Two plexal type AVMs resulted in residual AVMs supplied by the cisternal segment of the anterior choroidal artery, situated in the medial temporal lobe. To prevent postoperative hemorrhage from a small residual nidus, immediate postoperative angiography while the patient is still under general anesthesia should be performed to identify any residual nidus.

Adolescent↗
PubMed1992

Significance of positive Queckenstedt test in patients with syringomyelia associated with Arnold-Chiari malformations.

Ten patients with syringomyelia associated with Arnold-Chiari Type I malformations were evaluated. In each patient, a manometric Queckenstedt test was performed with the neck in various positions. No patient showed evidence of a block to the flow of cerebrospinal fluid (CSF) with the neck in the extended position; however, all showed a complete CSF block with the neck in a flexed position. Posterior fossa decompression with a C1-2 laminectomy was performed in nine cases, after which Queckenstedt test demonstrated free CSF communication in all nine with the neck in extension, in a neutral position, and in flexion. Postoperative magnetic resonance imaging showed shrinkage of the syrinx in the patients who underwent surgery. It is suggested that obstruction of the CSF pathway at the foramen magnum produced by neck movement is of importance in the formation and progression of a syrinx.

Adult↗
PubMed1992

An analysis of the venous drainage system as a factor in hemorrhage from arteriovenous malformations.

The authors studied the venous drainage system and its impairment in relation to risk of hemorrhage in 108 cases of supratentorial arteriovenous malformation (AVM). The proportion of AVM's undergoing hemorrhage (hemorrhagic rate) was calculated in relation to: 1) the number of draining veins (one, two, or three or more); 2) the presence or absence of impairment in venous drainage (severe stenosis or occlusion in draining veins); and 3) the location of draining veins (deep venous drainage alone, superficial venous drainage alone, or a combination of the two). Statistical analysis demonstrated that AVM's with the following characteristics had a high risk of hemorrhage: 1) one draining vein (hemorrhagic rate 89% in 54 patients); 2) severely impaired venous drainage (hemorrhagic rate 94% in 18 patients); and 3) deep venous drainage alone (hemorrhagic rate 94% in 32 patients). The present study suggests that the venous drainage system of AVM's is significantly associated with the risk of hemorrhage of these lesions. Therefore, careful preoperative angiographic evaluation of the venous drainage system is mandatory for decision making in the management of patients with AVM's.

Cerebral Hemorrhage↗
PubMed1992

[Primary intracranial melanoma: a case report].

A rare case of primary intracranial melanoma is presented in a 34-year-old man with initial symptoms of persistent headache. In magnetic resonance imaging(MRI), this case had all the characteristic findings of intracranial melanoma which had been reported previously. In 123I-iodoamphetamine-single photon emission CT (123I-IMP-SPECT), abnormal accumulation of 123I-IMP was recognized in early and late phase imaging, which was very specific to the lesion. This is the first report of 123I-IMP-SPECT performed on a primary intracranial melanoma. Tumor mass originated from pia mater was surgically resected, but the dissemination of tumor cells was recognized macroscopically. Pathological examination of the specimen showed very little malignant changes of melanoma cells, which was in contrast to the previous reports. Although, no standard chemotherapy of the primary intracranial melanoma has been established, DAV therapy to the dissemination of tumor cells into the subarachnoid space, and intravenous administration of interferon-beta were performed in this case. Methods of differential diagnosis and treatments of primary intracranial melanoma are reviewed and discussed.

Adult↗
PubMed1992

[A case of granulomatous hypophysitis].

The patient was an unmarried, 25-year-old woman who presented herself with amenorrhea and lactation as her chief complaints. Radiography revealed a tumor in the sella turcica. Upon neurological examination at the time of admission, there were no abnormal findings affecting the field of vision or visual acuity, and no abnormalities were seen in the fundus oculi. In endocrinological tests, the basal plasma values of pituitary hormones were normal except for that of prolactin, which was 69.1 ng/ml. The preoperative diagnosis was nonfunctioning pituitary adenoma, and this neoplasm was resected by the transsphenoidal approach. Postoperative histological investigation showed vermiculous destruction of the anterior lobe of the pituitary gland, and also scattered lymph follicles accompanying infiltration by numerous lymphocytes and multinucleated foreign-body giant cells, and deposition of calcium. These findings, together with the epithelioid cells gathered around them, pointed to a diagnosis of granulomatous hypophysitis. The causes of granulomatous hypophysitis are known to include syphilis, tuberculosis, sarcoidosis, mycotic granuloma, and foreign-body granuloma due to the rupturing of a Rathke's cleft cyst, but no evidence of any of these was found in this patient. Another known source of inflammatory lesions in the hypophysis is lymphocytic hypophysitis, which resembles Hashimoto's autoimmune disease of the thyroid gland, and which is characterized both by the formation of lymph follicles and by extensive lymphocyte infiltration. In relation to the cause of granulomatous hypophysitis, thinking that it might possibly be an autoimmune disease, we conducted an immunological investigation, and also made a serological study of autoantibodies, but obtained no positive results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Pheochromocytoma discovered in a pregnant woman: a case report].

A case of pheochromocytoma discovered at pregnancy is reported. The patient was a 27-year-old woman who had no symptoms before pregnancy. A sudden hypertensive attack occurred during vaginal examination at the 36th week of pregnancy. Magnetic resonance imaging (MRI) and ultrasonography showed a right adrenal mass. The level of catecholamine in blood and urine was beyond the normal limit. This patient was diagnosed as pheochromocytoma with pregnancy. Cesarean section was immediately done to avoid hypertensive crisis caused by spontaneous delivery. Blood pressure and blood volume were controlled by an alpha-blocker for one month after delivery, and, then the tumor was removed surgically. Pheochromocytoma with pregnancy is life-threatening for the mother and the fetus because of difficult diagnosis and complex clinical features. Early diagnosis and appropriate treatment are mandatory. Pathophysiological characteristics and the treatment of such specified statics are mainly discussed through our successful achievement.

Adrenal Gland Neoplasms↗
PubMed1992

[Experience with BALT magic catheter (PURSIL catheter); especially investigation about advantage, disadvantage and the applications].

BALT magic catheter (PURSIL catheter) is a new catheter which is more flexible and plaint than the TRACKER-18 catheter because its mid-section and distal portion are made from polyurethane and silicon rather than polyethylene. Because the PURSIL catheter is flexible, it cannot be inserted with a guide wire, although it can be inserted into circulation during injection of contrast medium. Its inner diameter, 3.5mm, is smaller than that (5mm) of the TRACKER. There are few reports of embolization with the PURSIL catheter, and these describe only embolization using adhesive liquid embolus material. Embolization using small particles through the PURSIL catheter has never been reported. We report the catheterization using the PURSIL catheter of 26 arteries in 15 patients. The catheter was used for superselective angiography to clarify feeder and amytal tests in 5 patients with AVM, and embolization using PVA particles (150-250 microns) was performed in 1 patient with AVM, 3 patients with dural AVM, 4 cases with meningioma and 1 patient with vertebral aneurysm. Small PVA particles were easily injected without resistance through this catheter. In only one patient with dural AVM, was catheterization with this catheter not successful, and that was because the distal portion of the internal maxillar artery was extremely tortuous because of severe atherosclerosis. No complications associated with the use of this catheter were observed. We think that the greatest advantage of this catheter is the safety afforded by not using a guide wire. A disadvantage of this catheter is that, because of its small inner diameter, only small particles, or liquid embolus material can be injected through it.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Fundus hemorrhage in patients with intracranial hemorrhage caused by cerebrovascular disease--its clinical significance].

To clarify the significance of fundus hemorrhage in the acute stage of intracranial hemorrhage due to cerebrovascular disease (HCVD), the incidence of such hemorrhage (retinal, preretinal, and subhyaloid hemorrhage) was examined and its correlations with the severity of the disturbance of consciousness and the prognosis were investigated. Two hundred sixteen HCVD patients with intracranial hemorrhage were the subjects of this study, including 87 cases of subarachnoid hemorrhage (SAH), 60 cases of hypertensive intracerebral hemorrhage (HICH), 54 cases of arteriovenous malformation (AVM), and 15 cases of Moyamoya disease. Fundus hemorrhage was recognized in 41 cases of SAH (47%), 5 cases of HICH (8%), 3 cases of AVM (6%), and 2 cases of Moyamoya disease (13%). The incidence of fundus hemorrhage was significantly higher in SAH than in the other type of HCVD associated with intracranial hemorrhage. Among patients with severe disturbance of consciousness (JCS 100-300), fundus hemorrhage was recognized in 69% with SAH, 13% with HICH, 17% with AVM, and none with Moyamoya disease. Therefore, patients with both fundus hemorrhage and severe disturbance of consciousness in the acute stage are most likely to have SAH, but HICH and AVM should be also taken into consideration. In patients with slight disturbance of consciousness (JCS 0-30), fundus hemorrhage was only noted in SAH (27%) and not in other types of HCVD associated with intracranial hemorrhage. Thus, SAH is highly likely to be the primary HCVD associated with intracranial hemorrhage, if we recognize fundus hemorrhage in patients with slight disturbance of consciousness in the acute stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Hemorrhage↗