We analyzed data from a three-headed SPECT camera (PRISM 3000) by using a computer software which enables the analysis, visualization and three-dimensional (3D) reconstruction of multiple data. We have conducted studies on dynamic SPECT, voxel distribution curves and 3D-SPECT images over the last few years. These diagnostic techniques were found to be useful for the quantitative analysis and visualization of the cerebral hemodynamics in patients with various brain diseases. The cerebral hemodynamics was evaluated before and after treatment, by using ^<123>I-IMP, ^<99m>Tc-HMPAO and ^<201>TlCl. Data from the three-headed SPECT camera were analyzed and reconstructed by a general-purpose data-visualizing software (Application Visualization System Medical Viewer ; AVS-MV) to obtain voxel distribution curves and 3D-SPECT images. Arteriovenous malformation (AVM) was well detectable as a high-accumulative image on dynamic SPECT, while the lesion exhibited an image defect on conventional static SPECT. The brain pathology was clearly visualized before and after treatment by the AVS-MV. Before appearance of vasospastic symptom, the change was revealed by early dynamic 3D-SPECT images. 3D-SPECT images of brain tumors were made from data obtained from the three-headed SPECT camera which can simultaneously measure and analyze the accumulation of 2 different nuclides. Brain tumors were detected as specific uptakes of ^<201>TlCl, while brain edema was visualized as a defect ^<123>I-IMP accumulation. Changes in ^<201>TlCl and ^<123>I-IMP accumulation before and after treatment were obtained in a short period of time and found to be useful for the detailed investigation of brain lesions. In cases of hydrocephalus, the cerebral hemodynamics, which varies corresponding to the shunt pressure, was quantitatively displayed as changes in voxel distribution curves and as changes in 3D-SPECT images. It was suggested that these imaging techniques can be used in the diagnosis of various brain diseases. Voxel distribution curves and 3D-SPECT images can be developed as functional images which express functional changes obtained from SPECT as morphological changes in the brain.

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Injury to the cranial nerves extending through the operative field or in areas adjacent to it costitutes a local complication of carotid endarterectomy. We present basic data on the anatomy and most frequent causes of injury to the individual nerves and describe a method for preventing cranial nerve injuries during carotid endarterectomy. Using this method resulted in injury to one or more cranial nerve in only 11 (8.3%) of 133 consecutive carotid endarterectomy patients treated at the National Cardiovascular Center from 1991 to 1996. Only 1 (0.75%) injury of the recurrent and superior laryngeal vagal nerve was permanent and the others were transient. The transient injuries Included 2 (1.5%) injuries of the hypoglossal nerve, 8 (6.0%) of the recurrent and/or superior laryngeal vagal nerve causing ipsilateral vocal cord paralysis, and 2 (1.5%) of the marginal mandibular branch of the facial nerve. Cranial nerve injury was not related to patient age or sex, symptoms, shunt usage, or bilateral surgery. However, it was more frequent in patients in whom the lesion reached the C2 or higher level. In our series of patients, the incidence of cranial nerve injuries during carotid endarterectomy was less frequent than usual and the vast majority were reversible. A thorough knowledge of topography and anatomy, combined with a cautious operative technique, should lower the incidence of cranial nerve injury during carotid endarterectomy.

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Twenty-two brain tumor operations were performed utilizing cortical mapping under local anesthesia for 18 patients. The tumors were situated in motor area in 16 patients and the speech area in 2 patients. The histological diagnoses were metastasis (13 cases), glioma (4 cases), and hemangioma (1 case). Before operation, acupuncture needles were inserted in 5 sites; zanzhu (B2), fengchi (G20), hegu (L14), quanliao (S18), and yuyao (Extra 5). The patient's head was fixed with a Mayfield head rest in the operating room. Craniotomy was performed under local anesthesia which was maintained throughout the operation. After opening the dura mater, the cortical surface was stimulated with a silver tipped bipolar electrode to identify the eloquent area. The threshold for evoking muscle contraction was 2-3 mA at 50 Hz. After dissection through the electrically silent cortex, monoparesis appeared in the very last stage in 4 of 17 operations. Dissection causing patients to complain of paresthesia at first, followed by motor responses at a higher threshold resulted in postoperative deficit in 2 of 2 operations. Dissection stopped at the electrically responsive area caused no deficit in 2 operations. Cortical stimulation for 2 tumors in the speech cortex caused no speech arrest. No deficit resulted after the operation. For example, a 52-year-old female presented with progressive left hemiparesis. The diagnosis was a metastatic tumor in the right posterior frontal lobe. Cortical mapping elicited a motor response along the edge of the posterior border of the tumor. Her hemiparesis gradually improved after the tumor removal. A 25-year-old male had bilateral metastatic tumors around the motor cortex. The tumor on the right was successfully removed. At the second operation, cortical mapping by our method was performed. The cortex just above the tumor responded to the stimulation. An Initial sensory response was followed by motor response at a higher threshold, so we thought that the tumor was situated in the sensory cortex. Postoperatively, weakness and numbness of the right hand appeared. Intraoperative cortical mapping is generally performed under general anesthesia. Only speech testing is performed with the patient awake. Continuous stimulation of motor cortex and motor evoked potential monitoring provides useful information, but in our method, the complaints expressed directly by the awake patients provided a simple and precise monitoring. Patients will feel no discomfort if recently developed short-acting intravenous anesthetics are used during opening or closing of the wound.

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Here we report 3 cases of central nervous system cavernomatosis and discuss the clinical feature, neuro-radiological appearance, and treatment strategy. Case I was thought to have fallen ill by a minor hemorrhage due to cavernoma at the medulla oblongata. A 53-year-old man was admitted for treatment of vertigo and hearing loss. An MRI showed multiple small lesions (37 pieces) in the brain including in the medulla oblongata and spinal cord. He was treated conservatively with steroid administration and showed much Improvement with this treatment. Case 2 was an incidentally discovered case. A 63-year-old man consulted us for a headache. An MRI showed multiple small lesions (18 pieces) in the central nervous system. Since these lesions were thought to be essentially asymptomatic, the patient was placed only under observation on an outpatient basis. Case 3 was a surgically treated case. A 35-year-old female complaining of gait disturbance was admitted to us for treatment. The cause of her symptom was determined to be myelopathy of the Brown-Sequard type at the C5 level. An MRI revealed multiple mixed intense lesions on both T1- and T2_-weighted images (17 pieces). Because the 3×2×2 cm cervical lesion located at the C4 - C5 Ievel was thought to be the cause of her symptom, total resection of the lesion was performed. Histological diagnosis was cavernoma. Her postoperative course was uneventful and she showed much improvement after the operation.

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We report a case of intractable epilepsy with porencephaly involving the sensory cortex. The patient underwent craniotomy with propofol anesthesia. The epileptogenic zone was resected under direct cortical stimulation in the awake condition after propofol infusion ceased. Intraoperative direct cortical stimulation revealed the precise 10calization of both sensory and motor functions, which could not be demonstrated by preoperative subdural stimulation studies. Therefore intraoperative direct cortical stimulation is considered effective in surgery for eloquent cortex.

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A case of huge parietal calvarial hemangioma accompanied with convexity meningioma is reported. A 70-year-old female was admitted with transient focal motor seizure of the left upper limb and a 10 year history of a painful subcutaneous hard lump in the right parietal region. Plain X-ray and tomography films showed a huge parietal radiolucent lesion containing many radiating bony spicules adjacent to a nodular calcified lesion. The angiography films showed delayed intraosseous accumulation of contrast medium feeding from the parietal branch of the middle meningeal artery. The CT scan and MRI films showed typical findings of a convexity calcified meningioma and intradiploic mass, which appeared as a homogeneous high density shadow on CT scan and hypointense shadow on MRI T1-weighted images, hyperintense on T2-weighted images and was enhanced markedly by Gd-DTPA. Histologically the calvarial tumor was a typical hemangioma and was not continuous with the meningothelial meningioma. The authors reviewed the clinical features, neuroradiological findings and treatment options of the calvarial hemangioma and discussed the correlation between the MRI findings and clinicopathological findings. The coexistence of meningioma and calvarial hemangioma is extremely rare, but it may have arisen from genetically related developmental abnormality, because both tumors are of mesodermal origin.

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A case of an avascular cystic meningioma with massive perifocal edema, which was unable to diagnose preoperatively, was reported. A 60-year-old man was admitted because of presenting with minimum left hemiparesis. CT scan and MRI disclosed a round cystic mass lesion in his right parietal lobe, with ring enhancement after administration of contrast medium. The mass lesion was accompanied with massive perifocal edema. Angiogram showed no evidence of meningeal vascularization nor tumor stain. Preoperative differential diagnosis was glioblastoma or metastatic brain tumor. At surgery, a cystic tumor with an attachment to the superior sagittal sinus was removed. Xanthochromic fluid without debris was obtained from the cyst. The cyst wall was also removed. The pathological findings confirmed the diagnosis of meningotheliomatous type meningioma. Dilated capillaries were often found facing the cystic cavity, where the number of tumor cells decreased and perivascular edema was observed. A secretory phenomenon was considered to be related to the cyst formation. An isolated subarachnoid space, which was detected as a peritumoral band on MRI, existing in the surface of the frontal aspect of the tumor, was considered to be related to the extensive perifocal edema. Postoperatively, the patient had an improvement in the hemiparesis. In this report, a possible relationship between cyst formation and extensive perifocal edema in meningiomas was discussed. Peritumoral band and dural tail sign detected on MRI appeared to have a diagnostic value in a case of cystic meningioma, distinguishing it from glioblastoma or metastatic brain tumor.

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The authors have successfully treated a case of dissecting aneurysm of the anterior cerebral artery, which presented with cerebra] infarction followed by subarachnoid hemorrhage. A 48-year-old female patient experienced severe headache and right hemiparesis. CT scan revealed cerebral infarction at the territory of the left anterior cerebral artery. One month later after conservative treatment, the patient experienced repeated bouts of severe headaches and eventually lost consciousness. CT scan revealed subarachnoid hemorrhage. An angiogram performed on the left carotid manifested segmental narrowing and dilatation at the left A1 and A'2 portion of the anterior cerebral artery. These findings suggest a dissecting aneurysm. The authors utilized the pterional approach in performing the operation. The left Al and A2 portion of the anterior cerebral artery were dark, and segmental aneurysmal dilatation was present. The base of the aneurysma] dilatation was successfully clipped, and the left A1 and A2 portion of the anterior cerebral artery wwas coated with fibrin glue. Following postoperative procedure and close monitoring, the course of the patient's recovery was steady and uneventful. Since cases of dissecting aneurysm of the anterior cerebral artery are rarely reported, the authors have discussed the possibility of surgical treatment when such cases arise.

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A 67-year-old man had previously undergone cervical laminectomy from C3 to C6 due to gait disturbance caused by cervical spondylosis and narrow canal. Two years after laminectomy, gait disturbance recurred and progressively worsened. Ten years after laminectomy, the patient was referred to our institution due to abrupt deterioration of cervical myelopathy. On admission, tetraparesis, numbness, and paresthesia of the arms and legs, and hyperreflexia were noted (neurosurgical cervical spine score : NCSS 5 points). Cervical radiographs and magnetic resonance images revealed a kyphotic deformity of the cervical spine and compression of the spinal cord at the C5 and C6 vertebral bodies. We performed C5 and C6 corpectomies and interbody fusion with an iliac bone graft and combined anterior fixation with the Orion plating system. Postoperatively, the kyphotic angle decreased from 30°, and the patient became ambulatory with aid (NCSS 8 points ; improvement rate 33%) . Surgical treatment for postlaminectomy kyphosis consists of decompression of neural elements, correction of the kyphotic deformity, and reconstruction of the cervical spine. Anterior decompression and fusion with an iliac bone graft and concomitant anterior plating is useful for the surgical management of postlaminectomy kyphosis.

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We present the case of a 70-year-old man with polymyositis associated with primary cerebral lymphoma, who was hospitalized for evaluation of headaches, dizziness and visual disturbance. Imaging studies revealed an enhanced cerebral mass. Following treatment with steroids, the mass regressed. However, the patient was subsequently readmitted 22 months later, and histologic analysis of a biopsy specimen confirmed a diagnosis of large-cell lymphoma. Approximately 23 months following his initial presentation, the patient developed muscle weakness and atrophy. A muscle biopsy specimen revealed polymyositis. Despite therapy, the patient died within I month. To our knowledge, this is the first reported case of polymyositis associated with primary cerebral lymphoma.

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