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ABSTRACT: This study investigated the angiographic changes in embolised arteriovenous malformations (AVMs) pre- and post-embolisation and preradiosurgery to clarify the usefulness of embolisation as a pretreatment for radiosurgery and the strategy of embolisation for the radiosurgical success. A total of 37 patients with cerebral AVMs treated over a period of 4 years was investigated. All the AVMs were embolised with N-butyl cyanoacrylate and 2 months later they were treated by radiosurgery. The size of AVM nidus reduced just following the embolisation (mean 21.9 ml to 3.9 ml). The angiogram taken in preparation for radiosurgery showed a further size reduction in the nidus of 16 AVMs, no change in 10 and regrowth in 11. In all the cases where size was reduced, the nidus was densely packed, while all the regrown AVMs were of the diffuse type. Five AVMs disappeared following radiosurgery, all of which were size-reduction or no-change cases. In conclusion, to achieve success in subsequent radiosurgery, nidus embolisation and the occlusion of fistulous and meningeal feeders are mandatory. Imprudent proximal feeder occlusion and the use of embolic materials with a risk of recanalisation should be avoided to prevent regrowth of the nidus, which may lead to errors in planning the radiosurgery to follow.
Journal of Clinical Neuroscience 10/2000; 7 Suppl 1:82-5. · 1.25 Impact Factor
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ABSTRACT: Two cases of facial neurinoma successfully treated with gamma knife radiosurgery are reported. Case 1, a 33-year-old female, developed a right-sided hemifacial spasm about five years ago. Then she suffered gradual progression of right-sided facial palsy, dysgeusia and reduction of lacrimation, but she had no hearing disturbance. T1-weighted MRI with gadolinium DTPA showed a well-circumscribed tumor at the geniculate ganglion extending to the middle cranial fossa. The tumor was treated with gamma knife radiosurgery which reduced its size, but didn't reduce the patient's facial palsy. Case 2, a 36-year-old female, presented with fluctuating facial palsy and sensorineural hearing loss lasting for fourteen years. T1-weighted enhanced MRI showed a well-enhanced tumor at the CP angle extending to the middle cranial fossa. The tumor was treated with gamma knife radiosurgery, which caused central tumor necrosis, but didn't reduce the tumor size. Meanwhile the patient's facial palsy improved. Gamma knife radiosurgery is apparently effective against facial neurinomas without producing serious complications such as complete facial palsy and hearing loss. Our study indicates that gamma knife radiosurgery is a useful therapeutic alternative for facial neurinomas.
No shinkei geka. Neurological surgery 03/1999; 27(2):171-5. · 0.13 Impact Factor
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ABSTRACT: We studied angiographic changes in embolized arteriovenous malformations (AVMs) by comparing pre- and postembolization angiograms and angiograms preceding radiosurgery. This study sought factors determining the usefulness of embolization as a pretreatment to enhance the success of subsequent radiosurgery. Thirty patients with cerebral AVMs treated in this manner over 4 years were studied. In these cases AVMs were embolized with cyanoacrylate and were treated with Gamma-knife radiosurgery. The mean size of the AVM nidus was reduced by a fraction of seven following embolization. The subsequent angiogram for planning radiosurgery showed further nidus reduction in 10 AVMs, no change in 12, and regrowth in 8. In all size-reduction cases the nidus was sufficiently packed, and 2 AVMs had thrombosed completely before radiosurgery. All the regrowing AVMs were of diffuse type; 6 were associated with already-developed leptomeningeal channels, and the remaining 3 were fed by newly sprouted meningeal feeders. Five AVMs disappeared following radiosurgery, all representing size-reduction or nochange cases. Analysis of cases with regrowth showed increased risk of that event with feeder occlusion of a multi-axially supplied AVM, lack of reduction of shunt flow, or remaining meningeal feeders. On the other hand, when embolization as pretreatment prior to radiosurgery succeeds in producing a small, compacted, plexiform nidus with slow shunt flow, it furthers the likelihood of successful radiosurgery. Nidus embolization and occlusion of fistulous and meningeal feeders are mandatory, while proximal feeder occlusion and use of embolic materials which risk recanalization should be avoided to prevent nidus regrowth.
Interventional Neuroradiology 11/1998; 4 Suppl 1:121-6. · 0.56 Impact Factor
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ABSTRACT: Cerebral blood flow (CBF) was measured by the stable xenon inhalation method, and the frequency distribution of flow levels analysed in patients with intracerebral haemorrhage, subarachnoid haemorrhage (SAH), vascular disease involving major arteries, lacunar infarction and normal subjects. The frequency distribution was skewed towards lower CBF values, and the mode, at which the frequency of values was highest, was lower than the mean CBF. Furthermore, the frequency at the mode was higher when mean CBF was low. Since many areas of the brain had lower flow than the mean CBF, it is suggested that attention must be paid to local flow levels as well as the overall mean value. A small decrease in mean CBF may mean the development of significant ischaemia in many regions.
Journal of Clinical Neuroscience 07/1998; 5(3):270-3. · 1.25 Impact Factor
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ABSTRACT: A case of a neurinoma arising from the first branch of the trigeminal nerve in a 40-year-old female is reported. The patient was admitted with the chief complaint of loss of Lt. visual acuity and mild hypoesthesia in the area of the first branch of the trigeminal nerve. A CT scan and MRI revealed a tumor extending through the superior orbital fissure into the orbita. Subtotal resection of the tumor was performed by a fronto-orbito-zigomatic approach and a histological diagnosis of neurinoma was made. Although the hypoesthesia remained, the visual acuity was markedly improved postoperatively. A neurinoma arising from the first branch of the trigeminal nerve is very rare. To our knowledge, including our case, only five cases which were described for clinical and diagnostic features and surgical management have been reported. There were three males and two females, and the age ranged from 1 to 57 years. Neurologically, all cases presented hypoesthesia in the area of the first branch of the trigeminal nerve and exophthalmus on admission. Visual disturbance was found in three cases. Radiologically, the enlargement of the superior orbital fissure was revealed in two cases. Angiography performed in three cases demonstrated the avascular mass. Three patients received CT scan and only the present case used MR imaging. Surgical resection was performed in all cases through various approaches. The fronto-orbito-zygomatic approach which was chosen in our case was useful for obtaining a sufficient operative view. As in our case, excellent outcome was achieved in three other cases due to successful tumor resection.
No shinkei geka. Neurological surgery 04/1998; 26(3):259-64. · 0.13 Impact Factor
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ABSTRACT: We studied 18 patients with cerebral arteriovenous malformations (AVM) who underwent embolization prior to surgery or radiosurgery. Two patients were cured with total occlusion of the AVM by embolization alone. Successful size reduction of the nidus in the range of 60-99% was obtained in all the other patients. Twelve patients underwent the radiosurgery following the embolization, one of whom obtained a complete cure. The AVMs in four patients were totally removed after the embolization. Although the purpose of embolization of AVMs is to reduce AVM size and shunt flow, the strategy of the embolization should be adjusted according to the treatment that is to follow, i.e. radiosurgery or surgery. We believe that peripheral nidi must be embolized prior to the radiosurgery, while deep-sited feeders must be embolized along with main feeders prior to the surgery.
Journal of Clinical Neuroscience 03/1998; 5 Suppl:58-60. · 1.25 Impact Factor
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ABSTRACT: The effect of glycerol on blood flow in tumoral and peritumoral tissue was measured in 32 patients with brain tumor, 17 gliomas and 15 meningiomas. Blood flow before and after the administration of glycerol was measured by stable xenon-enhanced computed tomography. The tumor part of glioma was significantly hypoperfused. In contrast, the tumor part of meningioma was significantly hyperperfused. Peritumoral edema of both glioma and meningioma was hypoperfused. After the administration of glycerol, blood flow increased in all regions except for the tumor part of glioma. Vascular responses to glycerol may be different in these two tumor types. The steal phenomena of blood flow might occur in cases of glioma.
Neurologia medico-chirurgica 12/1997; 37(11):825-8; discussion 828-9. · 0.61 Impact Factor
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ABSTRACT: Three patients presenting with subarachnoid hemorrhage due to aneurysmal rupture underwent cerebral blood flow (CBF) measurements before and after cisternal injection of papaverine hydrochloride. One patient showed prominent increases in CBF in the frontal lobe and basal ganglia after injection of papaverine, but paradoxical decreases in the parietal lobe and corona radiata. The other two patients had poor CBF response. Dense clotting in the basal cisterns may have prevented diffusion of the agent so that only the proximal trunks of the internal carotid, anterior cerebral, and middle cerebral arteries were dilated in the former case. The dilation of proximal trunks of cerebral arteries might steal blood flow from the parietal lobe and corona radiata, where the intraparenchymal arteries were maximally dilated and cerebrovascular reserve capacity was poor.
Neurologia medico-chirurgica 02/1997; 37(1):49-54. · 0.61 Impact Factor
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ABSTRACT: The treatment results of cavernous sinus meningioma with gamma-radiosurgery are reported. There were 18 cases of cavernous sinus meningioma, including 2 males and 16 females, whose age ranged from 39 to 63 with an average of 51.0 years. As prior treatments, operative tumor resection or biopsy had been carried out in 14 cases, and the pathology was verified. The other 4 cases were diagnosed clinically with radiological studies. The mean tumor diameter was 28.3mm (17.7-35.0) during the radiosurgery. The maximum dose ranged from 22 to 36Gy (mean 28.0Gy), with the marginal tumor dose ranging from 11 to 18Gy (mean 13.9Gy). Irradiation to the near-by optic nerves was less than 10Gy. Follow-up period ranged from 12 to 50 months with a mean of 25.5 months. MRI showed a minor tumor shrinkage in 9 (50.0%) and no obvious change in 8 (44.4%), and tumor progression in 1 (5.6%), which required a 2nd radiosurgery. Neurologically facial pain and facial dysesthesia were well improved (7/13). However the ophthalmoparesis was usually unchanged and only 1 out of 11 (9.1%) improved after radiosurgery. Deterioration of neurological signs was rare. Symptomatic edema presenting neurological signs was not seen. In conclusion, radiosurgery with a gamma-knife is one of the useful alternatives to operative intervention in the treatment of cavernous sinus meningiomas, not only for tumor control, but also for relief from the symptoms.
No shinkei geka. Neurological surgery 07/1996; 24(6):529-33. · 0.13 Impact Factor
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ABSTRACT: Coagulation and fibrinolysis factors were studied in six patients after local thrombolysis with urokinase (720,000 IU). Transient abnormalities, such as prolonged prothrombin time, decreased plasminogen and alpha 2-antiplasmin activities, decreased fibrinogen, and increased fibrin degradation products were seen on the day after thrombolysis, but tended to return to the normal range on the 4th day except for one patient who suffered from disseminated intravascular coagulation. Antithrombin III activity did not change so much. Therefore, the dosage of urokinase should be as low as possible to prevent fluctuations in the coagulation and fibrinolysis system.
Neurologia medico-chirurgica 06/1996; 36(5):300-4. · 0.61 Impact Factor
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ABSTRACT: Arteriovenous malformatios (AVMs) in the basal ganglia (BG) and thalamus (Thal) are difficult to treat by microsurgery or intravascular embolization alone, and the role of stereotactic gamma radiosurgery (gamma knife) of these AVMs is discussed. We have treated 324 cases of AVM with gamma knife since May 1991, and in 71 of these cases (19%) the AVM was in the BG or Thal. The results of gamma radiosurgery on AVMs of the BG and Thal were compared with the results of treating AVMs at other intracranial locations by gamma radiosurgery. The nidi were small (mean diameter: 16.4 mm), and they were treated with a mean maximum dose of 36.4 Gy and marginal dose of 19.9 Gy. The results were evaluated angiographically in 39 (55%) of the 71 cases, with a mean follow-up period of 23 months. The complete obliteration rate of AVMs in the BG and Thal 1 and 2 years after treatment was 54.3% and 92.0%, respectively, and the rate at the other locations was 42.9% and 76.0%, respectively. Adverse effects of this treatment in the AVM cases overall were rebleeding from the nidus in 5 cases (1.5%) and radiation necrosis in 4 cases (1.2%). In conclusion, AVMs of the BG and Thal were effectively and safely treated with the gamma knife, and stereotactic radiosurgery is a definitive alternative treatment for deep seated AVMs.
Nō to shinkei = Brain and nerve 05/1996; 48(4):351-6.
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ABSTRACT: The results of gamma knife radiosurgery for malignant skull base tumors were analyzed using repeated magnetic resonance imagings and neurological examinations. Nineteen malignant skull base tumors were treated and followed up for 22.3 months (5-40 months) using MR imagings. The mean age was 54.4 years old (ranging from 16-85). Ten were male and 9 were female. Prior to the radiosurgery, removal of the tumors in 17 cases, conventional radiation therapy in 7, and chemotherapy in 4 etc. were performed. The pathological diagnoses were chordoma in 6 cases, metastatic tumors in 5, epipharyngeal carcinoma in 2, adenoid cystic carcinoma in 2, and others in 4. The locations of tumors were the clivus in 8, the parasellar region in 5, the epipharynx in 2, the paranasal sinus in 2, C-P angle in 1, and intraorbital region in 1 (14 were intracranial and 5 were extracranial). The mean diameter of the tumor was 33.5mm. The mean maximum dose was 26.8Gy and the mean marginal dose was 12.9Gy during treatment. Repeated MR imagings revealed decrease of tumor size in 12 cases, no change in 1, and increase of tumor size in 5 (unknown in 1). Follow-up neurological examinations showed improvement in 3 cases, no change in 9, and deterioration in 7. There were 11 deaths during a mean follow-up period of 17.8 months (5-32 months) and another 8 cases are alive for a mean follow-up of 30.5 months (20-40 months) after the radiosurgery. Although the tumor size was large at the time of treatment, the results of gamma knife radiosurgery were promising. Considering the quality of life of patients with malignant skull base tumors, it is emphasized that gamma knife treatment is the method of choice compared with radical removal of the tumors.
No shinkei geka. Neurological surgery 04/1996; 24(3):235-9. · 0.13 Impact Factor
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Nō to shinkei = Brain and nerve 03/1996; 48(2):121-8.
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Acta neurologica Scandinavica. Supplementum 02/1996; 166:144-5.
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ABSTRACT: The effect of gamma knife radiosurgery for cranial base meningiomas was analyzed using magnetic resonance (MR) imaging in 33 patients followed up for a mean 26.5 months. There were 10 male and 23 female patients aged from 38 to 87 years (mean 54.5 yrs). Twenty-three patients had already had more than one open surgery before radiosurgery. The mean tumor volume was 16.8 cm3. The mean maximum dose was 29 Gy and the mean marginal dose was 15.1 Gy. Four patients were treated by two-stage treatment at 1- to 4-month intervals. Follow-up MR imaging revealed a decrease in tumor size in 10 patients, a small low intensity area in the tumor center in three, increase in tumor size in two, and no change in 18. After radiosurgery one patient had marked edema on MR imaging and showed cognitive deficits, and another three patients had neurological deterioration. All other patients were unchanged or improved. Growth control of cranial base meningiomas without severe neurological deficits can be achieved by radiosurgery.
Neurologia medico-chirurgica 02/1996; 36(1):7-10. · 0.61 Impact Factor
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ABSTRACT: More than 290 cases of cerebral arteriovenous malformation have been treated at our hospital by Gamma Knife radiosurgery since May 1991, of which 99 were followed with angiography for 1 year or more. The results from adult and pediatric age groups were compared. There were 70 adults and 23 children. Previous hemorrhage had occurred in 73.7% of the adults and 91.3% of the children. The mean volume of the nidus was similar in both groups: 4.2 cm3 in adults and 4.8 cm3 in children. In both groups approximately 70% of the cases fell into Spetzler and Martin grade III. The mean margin dose was 20.0 Gy in the adults and 20.5 Gy in the children. Complete nidus occlusion at 1 year occurred in 45% of the adults and 74% of the children. The rates at 2 years were 81 and 94%, respectively. Complications occurred only in adults and consisted of 2 rebleeds, 1 radiation edema and 1 radiation necrosis. Gamma Knife radiosurgery is considered to be safer and have a higher success rate in children than in adults.
Stereotactic and Functional Neurosurgery 02/1996; 66 Suppl 1:288-95. · 1.85 Impact Factor
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ABSTRACT: More than 290 cases of cerebral AVM had been treated by gamma knife radiosurgery since May, 1991, among which ninety-nine cases were angiographically followed up for at least one year. Comparison of the results between adult and pediatric AVMs were made. There were seventy six adult and twenty three child cases. Intracerebral hemorrhages in their past history were found in 73.7% of adult and 91.3% of child cases respectively, and the rate of intracranial hemorrhages in the pediatric group was higher than that in the adult group. The volume of the nidus of AVM in both groups was 4.2 ml in adults and 4.8 ml in children. Grade III of the Spetzler grading system occupied about 70% of all cases and was the most common grade in both groups. Treatment was performed with a mean marginal dose of 20.0Gy in adults and 20.5Gy in children. The complete occlusion of the nidus was obtained in 45% of the adult group and 74% of the pediatric group one year after, and in 81% and 95% respectively two years after the treatment was begun. As side effects, these were two rebleedings, one radiation necrosis and one radiation-induced edema in adults. However, no side effects were observed in children. It is considered that, when using gamma knife radiosurgery, pediatric AVMs are more likely to be occluded successfully and safely than adult AVMs.
No shinkei geka. Neurological surgery 10/1995; 23(9):773-7. · 0.13 Impact Factor
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ABSTRACT: A new treatment strategy for jugular foramen tumors using radiosurgery is reported. Six jugular foramen tumors, including 2 glomus tumors and 4 lower cranial neurinomas, were involved. Among them only one tumor was confined in the jugular foramen, but the others extended into the posterior fossa, the upper cervical portion or both. As an initial treatment, 3 cases underwent operative resection from suboccipital or transcervical route. The tumor sizes at radiosurgery ranged from 14.3 to 36.1 mm with a mean of 22.4 mm in diameter. They were treated with a marginal dose between 13 to 16.5 Gy (mean 15.6 Gy). Follow-up MRI showed an apparent tumor shrinkage in 4 and no change in 2. Central tumor necrosis was found in 4 cases, but tumor progression was never observed in the mean follow-up period of 19 months. No complication occurred during and after the radiosurgery. These results indicate that radiosurgery is effective for the control of jugular foramen tumors with acceptable risk. Large tumors extending to the upper cervical portion and posterior fossa can be treated by operative resection combined with radiosurgery.
No shinkei geka. Neurological surgery 09/1995; 23(8):671-5. · 0.13 Impact Factor
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ABSTRACT: A 58-year-old female, who had suffered from Weber-Christian disease for 26 years, presented with subarachnoid hemorrhage. Cerebral angiography showed dilatation of the basilar tip. An operation was performed in the chronic stage. The wall of dilated basilar artery was tough, but that of the right superior cerebellar artery was very thin and three small aneurysms were found on the right middle cerebral artery. Blood levels of fibrin degradation products, plasmin-alpha 2-plasmin inhibitor complex, and thrombin-antithrombin III complex were increased. The abnormality of the coagulation-fibrinolysis system and the fragility of the cerebral arteries related to Weber-Christian disease were probably the cause of the subarachnoid hemorrhage.
Neurologia medico-chirurgica 08/1995; 35(7):454-7. · 0.61 Impact Factor
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ABSTRACT: A 30-year-old male with Albright's hereditary osteodystrophy, pseudopseudohypoparathyroidism, and nephrogenic diabetes insipidus presented with hemifacial spasm persisting for 2 years. This association is extremely unusual. Angiography revealed markedly tortuous carotid and vertebral arteries inconsistent with his age. Neurovascular decompression of the left vertebral artery achieved only partial resolution of the spasm.
Neurologia medico-chirurgica 07/1995; 35(6):380-4. · 0.61 Impact Factor
