Interventional angiography via the transbrachial approach is sometimes difficult due to the lack of an appropriate guiding catheter. The authors therefore developed a new guiding catheter for transbrachial interventional angiography. The newly developed catheter contains a special metal mesh in the wall of the curved portion which maintains the round shape of the intraluminal space. Coaxial insertion and manipulation of the microcatheter are both easy and smooth in our experience, which includes superselective intraarterial drug infusions in 10 patients, therapeutic embolization of an arteriovenous malformation in 3 patients, and superselective angiography in 3 patients. Transbrachial 4-vessel studies were also carried out in 34 patients. A local subcutaneous hematoma was found in l patient, but no severe complications such as cerebral embolism or brachial artery obstruction occurred. Cerebral angiography and interventional procedures via the transbrachial approach are possible using this new catheter without the need for special techniques.

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Superselective intraarterial thrombolysis was performed in 29 of 53 consecutive patients with evolving acute cerebral infarction due to occlusion of the middle cerebral artery (MCA), while the other 24 patients were treated conservatively. Based on angiographic findings, the occlusion sites were classified into 3 types : 1) M1 proximal, occlusion at the MCA trunk proximal to the lenticulostriate arteries (thrombolysis 4/conservative treatment 15 patients) ; 2) M1 distal, occlusion at the MCA trunk distal to the lenticulostriate arteries (15/2 patients) : 3) M2-M4, occlusion after the MCA branches (10/7 patients). Successful recanalization with clinical improvement was achieved in 18 of 29 patients (62.1%). M1 distal occlusions were more likely to be recanalized successfully (11/15, 73.3%) , whereas successful thrombolysis for M1 proximal occlusion was very difficult to achieve (1/4, 25.0%) because of the difficulty in preserving the lenticulostriate arterial territories. The successful recanalization rate in patients with M2-M4 occlusions was slightly lower (6/10, 60.0%) than in those with M1 distal occlusion (11/15, 73.3%) due to technical catheterization problems. The successful recanalization rate was higher in patients with embolic occlusions (12/16, 75.0%) than in those with thrombotic occlusion (6/13, 46.2%) There was little or no difference in the rate of hemorrhagic transformation with clinical exacerbation between thrombolytically (20.7%) and conservatively (16.7%) treated groups. These results indicate that local thrombolysis for acute MCA occlusion is safe and efficacious, particularly in patients with M1 distal occlusion. The involvement of the lenticulostriate arteries is an important determinant of successful thrombolysis.

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Forty-three patients with the unilateral type of acoustic neurinoma who were treated with gamma knife radiosurgery were analyzed from the viewpoint of tumor control. The follow-up period ranged from 22 to 55 months (mean 36 months). The tumors, which ranged in volume from 0.1 to 18.7 ml (mean 4.0 ml), were treated with marginal radiation doses of 9-15 Gy (mean 13.4 Gy) with multiple isocenters (mean 8.7). The Actuarial tumor reduction rates were 42% at one year, 75% at 2 years, and 92% at 3 years after gamma knife radiosurgery. Transient tumor expansion (mean 2.1 mm) was seen in 33% of patients, which correlated with previous surgical cases (p=0.002 by multiple regression analysis). The present control rate was 91%. Single-photon emission computed tomography (SPECT) was performed on 15 selected patients before and 1 year and 2 years after gamma knife radiosurgery ^<201>TICl SPECT was used to determine tumor viabillty and the early and delayed ^<99m>Tc-DTPA-human serum albumin (HSA-D) SPECT images were used to assess tumor vascularity and permeability, respectively. The T1 index and HSA-D index of the delayed images were not significantly different from the respective preoperative values. However, there was a statistically significant decrease in the HSA-D index of the early images 1 year after treatment (p=0.02). A statistically significant reduction in tumor volume was seen 2 years after treatment in these 15 patients, meaning that a reduction in tumor vascularity was followed by a reduction in tumor size. One patient underwent srugical excision of the tumor 18 months after gamma knife radiosurgery because the tumor had expanded and resulted in cerebellar ataxia. Histopathologic investigation revealed the presence of some tumor cells with irregularly shaped nuclei and marked intimal thickening or obliteration of the tumor vessels. These findings suggest that the reduction of tumor vascularity may be one of the effects of gamma knife radiosurgery, which gradually decreases the size of acoustic neurinomas.

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We report a case of delayed intracerebral hemorrhage caused by cerebral hyperperfusion after carotid endarterectomy (CEA). The patient was a 70-year-old hypertensive man who presented with aphasia. CEA was performed to relieve severe stenosis of the left internal carotid artery. Magnetic resonance (MR) imaging and single-photon emission computed tomography (SPECT) performed 10 days and 18 clays after surgery, respectively, showed a hyperperfused area in the subcortical region of the left cerebral hemisphere. Although the patient was discharged without neurological deficits, he developed a subcortical hemorrhage on the 24th postoperative day in the region shown to be hyperperfused on MR imaging and SPECT. Longer follow-up and vigorous control of blood pressure are necessary to prevent the occurrence of intracerebral hemorrhage in patients with cerebral hyperperfusion following CEA.

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A 21-year-old male was admitted to our hospital due to hypoglycemic attack. Lavoratory data showed a high blood level of PRL (62.5ng/ml), insulin, glucagon, Ca, and parathyroid hormone due to multiple endocrine neoplasia type I (MEN I). Insulinoma and glucagonoma were found in the pancreas and extirpated. After surgery, the patient was transferred to Department of Neurosurgery in our hospital for treatment of the pituitary tumor. Magnetic resonance (MR) imaging revealed microadenoma in the pituitary gland, and the tumor was completely extirpated via a transsphenoidal approach. Immunocytological investigation of the surgical specimen showed that it was immunoreactive for PRL, GH, TSH, LH, and FSH. The patient's PRL blood level became normal postoperatively. Functional adenoma is seen more frequently in patients with MEN I -associted pituitary adenoma than in patients without MEN, especially GH- or PRL-producing tumors. The prognosis for patients with MEN I is generally determined by the clinical course of their pancreatic tumors. Therefore, the treatment strategy for the pituitary adenoma is determined by the patient's age, general condition, and pancreatic tumor prognosis.

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A patient with a history of nasal bleeding presented with abducens palsy and was found to have Wegener's granulomatosis. Computed tomography (CT) scanning showed an area of abnormal density in the upper nasal cavity and ethmoidal sinus ; destruction of the frontal base was also noted. The bilateral frontal lobe was shown as a low-density area. The dura mater and wall of the cavernous sinus were markedly enhanced on gadolinium-DTPA (Gd-DTPA) magnetic resonance (MR) images. A biopsy specimen of the thickened dura mater showed a granulomatous lesion mainly located in the subarachnoid space, with marked inflammatory cell infiltration in the Virchow-Robin space. The small blood vessels were occluded by infiltrating inflammatory cells. These findings suggested that the low-density area on the CT scan was due to ischemic change. Our experience with this case indicates that investigation of meningeal enhancement using Gd-DTPA MR imaging is useful in determining the location and extent of central nervous system lesions in patients with Wegener's granulomatosis.

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A case of multiple cerebral aneurysms associated with neurofibromatosis is reported. In April, 1995, a 64-year-old woman, who had been clinically diagnosed as having neurofibromatosis about 20 years prevlously, underwent check-up screening of cerebral diseases, and multiple cerebral aneurysms were found incidentally by MR angiography. Angiography performed in our hospital revealed 2 unruptured aneurysms ; a saccular aneurysm of the right middle cerebral artery (MCA), a local but non aneurysmal dilatation of the right internal carotid artery, and a giant fusiform aneurysm of the basilar artery. The patient was operated on with clipping and wrapping of the right MCA aneurysm and discharged without neurological deficits. The biopsy specimen of the right superficial temporal artery(STA) revealed fibrous thicknening of the intima and partial fragmentation of the internal elastic laminae. With analysis of 18 cases in previous reports, those pathological changes on the vessels might be related with the formation of cerebral aneurysms.

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A 51-year-old female presented with a sudden onset of headache on Sept. 19, 1987 and was diagnosed to have subarachnoid hemorrhage (SAH) of unknown cause. Two years later, an MRI showed a small isointensity mass in the pineal region. In Jan. 26, 1995, a postcontrast T1-weighted MRI revealed a homogenous high intensity mass in the pineal region causing obstructive hydrocephalus. Except for bilateral papilledema, her neurologic examination was normal. Tumor markers, both in serum and cerebrospinal fluid, were negative. The tumor was totally removed via an occipital transtentorial approach in 2 procedures during the same admission. Histological examination revealed pineocytomatous rosettes and electron microscopic examination revealed synapse formations, consistant with the diagnosis of pineocytoma with neuronal differentiation. Neither irradiation nor chemotherapy was performed after surgery. This case highlights several points. Firstly, although there was no difinite evidence that her SAH was caused by the tumor, one should keep in mind that SAH may be the initial presentation of pineocytomas. Secondly, since the growth of pineocytomas appeared to be relatively fast, at least, an annual follow up MRI would be necessary while considering conservative treatment. Finally, total removal of tumor would be the treatment of choice for pineocytomas, irrespective of histological findings with variations in differentiation.

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A 56-year-old man presented with chemosis of the left eye. CT showed a dilated left superior ophthalmic vein, suggesting a carotid cavernous fistula. Cerebral angiogram revealed multiple dural arteriovenous fistulas at the superior sagittal sinus, the left lateral sinus and the jugular bulb, and multiple dural sinus occlusions involving the superior sagittal sinus, the left lateral sinus and the left inferior petrosal sinus. Arterial supply was from the branches of the external carotid artery and the meningeal branch of the vertebral artery. Venous drainage routes via the cortical vein to the cavernous sinus, via the deep cerebral vein to the straight sinus, and directly to the internal jugular vein were opcified. After embolization of the branches of the external carotid artery, chemosis was improved, but the dAVF of anterior part of the superior sagittal sinus supplied by the anterior falcine artery became more prominently visualized. The literature of multiple dAVF's was reviewed, and the mechanism of their development and clinical implication are discussed.

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We describe magnetic resonance (MR) imaging susceptibillty artifacts seen in EPI (echo planar image) T2-weighted images in a patient with chronic subdural hematoma. A 69-year-old female who had undergone open heart surgery for mitral valve replacement 12 years previously presented with progressive right motor weakness of 4 days' duration. Immediately after the open heart surgery, she had experienced transient expressive aphasia and right hemiparesis. A CT scan taken on the present admission revealed a left subdural hematoma. After evacuation of the hematoma from the double-layered cavity through trephination her symptoms resolved completely and she was able to return to her previous lifestyle. MR imaging showed the typical findings of chronic subdural hematoma, except that the hematoma cavity protruded into the frontal operculum, which appeared to be related to a previous cerebral infarct followed by extensive atrophic changes, and there was heterogeneity of the hematoma content, suggesting a double-compartment cavity. EPI T2-weighted imaging, which is routinely carried out in our institution in patients with head injuries, revealed 3 susceptibility artifacts around the left sylvian fissure. Based on the MR image appearance, susceptibility artifacts seem to be caused by metallic particles containing ferrous material. These artifacts are frequently reported in patients after mechanical valve replacement surgery. However, it is not likely that they originate from the mechanical valve alone, since these foci are also seen in patients after coronary artery bypass grafting. Whatever their origin, it should be borne in mind that these artifacts can occur following cardiac surgery. especially mitral valve replacement.

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The authors report on their use of the transsulcal approach to intraventricular tumors of the trigonum. The approach to the trigonum of the lateral ventricle remains controversial because conventional approaches to these lesions sometimes cause neurological deficits. The superior parietal lobe incision is the most useful since it avoids the visual pathway and speech and sensorimotor areas. However, even when using this approach the retraction force may results in cerebral injury because the pathway to the trigonum is rather long. To minimize the retraction force, we have used the transsulcal approach for the resection of tumors in the trigonum with excellent results. This approach provides less invasive access to the trigonum of the lateral ventricle.

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