The concept of cerebrovascular accident in the embryonal and fetal periods is obscure. It may affect neuronal development as an encephaloclastic insult in the later stages of development, although the specific critical period for this is completely unknown. Furthermore, vascular development may depend on the neuronal maturation process if the primary encephalodysplastic lesion occurs early in the development process. Various cases of cerebrovascular accident occurring in the fetal brain are summarized, and the specific nature of the disease is discussed in light of the relation between vascular development and the neuronal maturation process. Cerebrovascular diseases during the fetal period include intraventricular hemorrhage, ischemic lesions due to vascular occlusion occurring in monozygotic twins, various vessel abnormalities, etc. Cerebral dysgenetic malformations, on the other hand, result in a variety of developmental abnormalities of vascular structures. The present study emphasizes that the neuronal maturation process and vascular development may have a major effect upon each other depending upon the stage when the accident occurs in the fetal period. The authors describe this phenomenon in the fetal period as a specific etiopathophysiological entity : "neuro-vascular develop mental interaction".

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Changes in proliferative activity in 12 cases of recurrent glioma were investigated using MIB-1 antibody and the mitotic index (MI) . Four astrocytomas showed malignant changes in the recurrence group (group A), along with an increase in both the MIB-1 staining index (SI) and MI. Three malignant gliomas that recurred at an average 9.7 months after the first surgery showed increased proliferative indices (group B). However, 5 glioblas-tomas exhibited a marked decrease in proliferative index in spite of their earlier recurrence (mean, 6.8 months) (group C). The mean survival time after the second surgery tended to be longer in group C (12.0 months) than in group B patients (6.4 months), although the difference did not reach the level of significance. It appeared that factors other than the proliferation of tumor cells may have contributed to the increase in tumor volume in group C, and we speculate that interstitial edema may play a role in this.

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Among 230 patients with extracranial carotid stenosis, 20 patients were performed staged bilateral carotid endarterectomy (CEA). Mortality and morbidity in initial CEA was O%. Mean interval period between initial and second CEA was 9.2 months. Mortality and morbidity following the second CEA was 10% (2/20 patients) . Cause of complications in 2 patients was lower cranial nerve palsy on the next day of surgery. During follow-up period (mean 60.7 months), 2 patients died of cardiac events. Other patients are alive independently without cerebral ischemic event. Therapeutic efficacy for prevention of the ischemic events would be stressed in bilateral CEA if we properly performed the surgery not to injure both lower cranial nerves and surrounding tissues in initial CEA and second CEA.

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Surgery for deep central lesions in the parasellar, infrachiasmatic, and interpeduncular cistern regions has recently been accomplished through an orbitozygomatic approach. However, when those lesions are extending caudalward, this approach may not offer sufficient exposure for complete obliteration. For the purpose of the Sufficient exposure of these lesions, the authors have adopted a combined surgical approach which consists of subtemporal and orbitozygomatic approaches. The patient is placed in the supine position with the head rotated 45° to the contralateral side and tilted 10° downward. The orbitozygomatic craniotomy (with or without removal of the anterior clinoid process and exposure of the superior orbital fissure) as well as an ordinary temporal craniotomy is performed. After opening the dura mater, the lesions are approached through pterional, anterior subtemporal (the bridging veins coming off the tip of the temporal lobe are divided) and subtemporal routes. During these 3 serial approaches, the arachnoid membranes covering the sylvian fissure, basal cistern and ambient cistern are opened in succession. This permits complete liberation of the temporal lobe from its attachments to the frontal lobe and brain stem. This approach results in wide exposure with minimum brain retraction. Based on these advantages of the procedure and on our experience, it is concluded that this combined approach is useful for the surgical treatment of central skull base lesions, especially those which are extending caudalward.

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Scoliosis is a late-onset skeletal complication of myelomeningocele. Herein, we discuss a case of progressive scoliosis that occurred 6 years after the correction of myelomeningocele in a patient who presented a Chiari type II malformation with syringobulbia, syringomyelia, and the tethered cord syndrome. While scoliosis can be caused by syringobulbia, syringomyelia, or the tethered spinal cord syndrome, in this case a single cause for the scoliosis Could not be identified. To decompress the craniocervical region, the syrlngobulbia was opened by C1 laminoplasty, after which the conus medullaris was untethered before the orthopedic correction of the scoliosis. For the surgical repair of such cases, we recommend the following order : the spinal cord should be given posterior fusion with instrumentation, followed by correction of the scoliosis.

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Intracranial hematomas remote from the site of the initial craniotomy are rare but serious complications. We report a case of cerebellar hemonrrhage and multiple supratentorial hematomas that developed after a right frontotemporal craniotomy for intracranial aneurysms. We speculate that these hematomas occur as a result of a combination of wide variation in perioperative blood pressure and poor cerebral venous circulation. Care should be taken to avoid overdrainage of cerebrospinal fluid during surgery. In addition, expert perioperative anesthetic management is important in preventing the occurrence of remote intracranial hematomas.

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A case of cranial nerve paralyses after coagulation of the middle meningeal artery is reported. A 56-year-old female had experienced transient amnesia. CT and MRI revealed a 4 x 3 cm mass with homogeneous enhancement at the outer third of the right sphenoid ridge. Right external cerebral angiography showed a tumor stain from the dilated middle meningeal artery. Right frontotemporal craniotomy was performed, and the right meningeal artery was coagulated at the foramen spinosum to reduce the amount of bleeding. Histological examination of the excised tumor confirmed that it was a meningotheliomatous meningioma. Immediately after surgery, the patient com-plained of hypesthesia of the right trigeminal nerve and diplopia due to right abducens paralysis. It was thought that the paralysis of these cranial nerves was the result of the coagulation of the middle meningeal artery. Six months after surgery, the abducens nerve paralysis had almost completely resolved, although the patient continued to experience hypesthesia and paresthesia of the right ophthalmic and maxillary nerves.

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Middle cerebral artery (MCA) dolichoectasia is rare. We report 2 cases of MCA dolichoectasia. The patients complained of headache or dizziness, respectively. Postcontrast CT scans showed small enhanced masses at the site of the MCA lesions that seemed to be cerebral aneurysm. The patients were examined by cerebral angiography after admission to our hospital. However conventional angiography could not completely differentiate these lesions from saccular aneurysms. Three-dimensional (3D)-CT angiography successfully demonstrated the configuration of the lesion clear1y to allow the diagnosis of dolichoectasia. We concluded that MCA dolichoectasia should be differentiated from saccular aneurysm preoperatively and that 3D-CT angiography is a useful tool for this purpose.

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This report describes a rare case of Paget's disease complicated by an intracerebral hemorrhage. The patient, a 71-year-old male, was admitted to hospital due to right hemiparesis and a sudden onset of disturbances affecting his consciousness. Computed tomography (CT) scans showed a left putaminal hemorrhage, clearly thickened calvarium, inner surface skull irregularities and a marked thickening of the skull base that showed sclerotic changes. A diffuse thickening of the calvarium is also seen in X-rays of the skull in addition to advanced basal sclerosis with platybasia. The histopathologic findings from surgically obtained specimens of the calvarium revealed trabecular thickening and what is often termed the "mosaic pattern". X-rays of the systemic bodies showed cortical enlargement and thickening, and ^<99m>Tc-HMDP bone scintigrams revealed a negative RI uptake. The serum alkaline phosphatase and urinary hydroxyproline levels were normal. Thus, based on these findings, the patient was diagnosed as having Paget's disease of the polyostotic type in the non-active phase. Hemostatic complications often occur in Paget's disease patients undergoing surgery of the skull, but few cases have been described in detail. The following conclusions have been drawn from our own surgical experience and from what has been reported in the literature:1) the location and quality of the pagetic changes should be carefully assessed because pagetic bone shows different aspects during each phase ; 2) pre-operative evaluations, such as angiographic inspection, are necessary to prevent major bleeding and, 3) attention should be paid to the complications associated with the basilar impression.

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During cranioplasty, surgeons secure the cranial flap with thread or thin wire sutures by inserting them through holes made in the skull. we have devised a new insertion method using the Bobbin Threader^[○!R] . The major advantages of this technique are ease in suturing, shortened closure time, and minimal risk of dural injury.

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