Navigation-guided fence-post tube technique for resection of a brain tumor: technical note.

INTRODUCTION: A new technique using a navigation system to minimize the influence of brain shift and to perform precise resection of brain tumors is demonstrated. To determine the resection plane, one to six tubes were inserted around the tumor under the guidance of a navigation system before dural incision. RESULTS: This technique termed the "navigation-guided fence-post tube" (NGFP) procedure was used to treat 34 patients with intraaxial brain tumors including gliomas (23 cases), malignant lymphomas (4 cases) and metastatic tumors (7 cases). Tumors were removed totally in 23 cases (67.6%), subtotally (95% or more removal) in 6 cases (17.6%) and partially (less than 95% removal) in 5 cases (14.7%). The cases with subtotal or partial resection contained tumors that were close to or involved the eloquent area, or disseminated lesions. No complications due to tube insertion occurred. CONCLUSION: NGFP is a useful and safe technique for brain tumor surgery with no influence of brain shift during tumor resection.

Image-guided stereotactic radiosurgery with the CyberKnife for pituitary adenomas.

This study demonstrates the clinical usefulness of image-guided fractionated stereotactic radiosurgery with the CyberKnife system. Twenty-one patients with pituitary adenomas received image-guided stereotactic radiosurgery with the CyberKnife, and were followed up for more than 18 months. The patients consisted of 14 with non-functioning adenomas, 3 with prolactinomas, 2 with acromegaly, and 2 with ACTH-producing tumors. In 20 cases, fractionated radiosurgery was performed. The change in the tumor volume, visual acuity, hormonal function, and complications by this therapy were analyzed in each case. The volume of the tumors ranged from 0.2 cm (3) to 34.9 cm (3) (mean +/- SD: 11.3 +/- 9.2 cm (3)). The mean volumes of the non-functioning and functioning adenomas were 13.3 cm (3) and 7.5 cm (3), respectively. The marginal irradiation dose ranged from 6.4 Gy to 27.7 Gy (mean: non-functioning adenomas 12.6 Gy, functioning adenomas 17.5 Gy), as a dose of a single fraction. The follow-up periods ranged from 18 months to 59 months (mean +/- SD: 35.3 +/- 10.7 months). The tumor control rate was 95.2 %. In 1 case, visual acuity worsened due to cystic enlargement of the tumor. Hormonal function improved in all of the 7 functioning adenomas. The hormone level normalized in 1 prolactinoma, and decreased to less than normal in 1 ACTH-producing adenoma. In 2 cases, hypopituitarism occurred after the therapy. Image-guided stereotactic radiosurgery with the CyberKnife is effective and safe against relatively large pituitary adenomas. Careful long-term follow-up of the patients is necessary because of delayed cystic enlargement of the tumor in rare cases.

Surgery for expansion of spinal tuberculoma during antituberculous chemotherapy: a case report.

We report a case of intramedullary spinal tuberculoma in a girl aged 2 years and 6 months. At the age of 18 months, the patient was hospitalized for 2 months with tuberculous meningitis. Tuberculomas then appeared in the thoracic spinal cord, and the patient developed paraparesis despite continuation of chemotherapy. Spinal magnetic resonance imaging demonstrated multiple ring-enhanced lesions in the cord on the T1-weighted image; on the T2-weighted image, the lesions had a bright core surrounded by a hypointense rim. Laminectomy and partial excision were performed, and the paraparesis improved. In addition to antituberculous chemotherapy and dexamethasone, surgical decompression was needed to treat the expansion of the spinal tuberculoma.

Intractable epilepsy associated with multiple cavernous malformations: case report.

OBJECTIVE AND IMPORTANCE: Epilepsy associated with cavernous malformations is often effectively controlled by lesionectomy alone. Detailed preoperative evaluation is necessary if the lesions are multiple and the seizures are medically intractable. We report on a patient with multiple cavernous malformations associated with medically intractable seizures who became seizure-free after a single gyrus resection. The importance of electroencephalography with video monitoring is emphasized. CLINICAL PRESENTATION: The patient was a 25-year-old man with a 10-year history of complex partial and generalized convulsions. Magnetic resonance imaging revealed more than 10 cavernous malformations. Video-electroencephalographic monitoring indicated that seizures originated from either the frontal or temporal lobe of the right hemisphere. INTERVENTION: Subdural electrodes were implanted, covering both frontal and both temporal lobes. The seizures originated in the right frontal lobe. The gyrus, including a calcified cavernous malformation, was removed, and multiple subpial transections of the surrounding cortices were performed. The patient has been free of seizures for 22 months after surgery. CONCLUSION: Medically intractable seizures associated with multiple cavernous angiomas can be controlled by a single resective procedure.

[Effect of epilepsy surgery based on magnetic resonance imaging (MRI) classification].

We prospectively analyzed the effect of surgical procedures in epilepsy patients, except for those with mesial temporal lobe epilepsy. Twenty patients with a mean age of 26 years (range 3 to 58 years, 10 male and 10 female) underwent the surgical procedures. These patients were divided into 3 groups according to MRI findings, as follows; group A (localized type): localized lesions such as angiomas or benign tumors, group B (widespread type): widespread lesions such as regional encephalitis or stroke, visible on anatomical neuroimaging, and group C (cryptic type): no lesion visible on anatomical neuroimaging. Following surgery, 11 (85%) of the 13 patients in group A were seizure-free, one showed worthwhile improvement, and one, whose lesion was not removed totally, was unchanged. In group B, two patients (50%) were seizure-free and 2 (50%) showed worthwhile improvement. All the patients in group C showed worthwhile improvement. Lesionectomy, cortical excision, multiple subpial transection (MST) or a combination of these procedures were effective in groups A and B. Patients in group C had a chance to obtain worthwhile improvement by corpus callosotomy or cortical excision. Intracranial EEG recording provides useful information for epilepsy surgery in intractable cases.

Cerebral metabolism of the remote area after epilepsy surgery.

To clarify whether epilepsy surgery improves cerebral metabolism, pre- and postoperative positron emission tomography (PET) scans were performed, with special reference to hypometabolism outside the resected epileptogenic zones in nine patients (8 males, 1 female) with medically intractable complex partial seizures and multiple hypometabolic zones. Seven patients underwent unilateral anterior temporal lobectomy, one patient underwent selective amygdalohippocampectomy, and one patient underwent parieto-occipital cortical resection and anterior temporal lobectomy. PET scans were obtained at least 6 months after surgery. Eight patients became seizure-free, and one patient had fewer than three seizures per year. Four patients showed improved glucose metabolism in the formerly hypometabolic zones, which were remote to the surgical site and ipsilateral to the epileptogenic foci. Five patients, who showed bilateral temporal hypometabolism preoperatively, had contralateral temporal hypometabolism after surgery. The relative glucose uptake in four of these patients showed increased metabolism of the adjacent lobes ipsilateral to the surgical site. The lobes that showed increased glucose metabolism after surgery were mostly frontal. Hypometabolism is reversible in the ipsilateral remote area, and may be caused by inhibition via the intercortical pathway. Contralateral temporal hypometabolic zones that persist after surgery may be caused by a different mechanism, and neither indicate the presence of seizure foci nor affect the seizure outcome.

An angiographically occult arteriovenous malformation in the medial parietal lobe presenting as seizures of medial temporal lobe origin.

We present an unusual case of a patient who was diagnosed with temporal lobe epilepsy and whose seizures were reduced markedly after excision of an angiographically occult arteriovenous malformation (AVM) located in the left medial parietal lobe. A 38-year-old man had complex partial seizures characterized by motionless staring with oroalimentary and behavioral automatisms since the age of 15 years. Magnetic resonance imaging (MRI) demonstrated a small lesion extending from the left posterior cingulate gyrus to the precuneus. There was no MRI evidence of mesial temporal sclerosis. Intracranial EEG recordings showed ictal onset from the left medial parietal lobe propagating to the medial temporal lobes. Clinical signs appeared when these discharges reached the temporal lobes. After excision of the lesion (which was histologically confirmed as an AVM), together with the marginal cortex, seizures were reduced significantly. Careful diagnostic evaluation of lesions such as the this one may reveal an epileptogenic lesion (zone) far from the region where scalp ictal discharges seem to arise. In our case, we hypothesize that false localization was due to propagation of ictal discharges from the parietal focus through the limbic system.

Urinary metabolites of valproic acid in epileptic patients.

The urinary excretion of valproic acid (VPA) and its metabolites (3-keto VPA, 3-OH VPA, and VPA-glucuronide) in 6 epileptic patients was studied using gas chromatography-mass spectrometry. The amount of VPA and 3-OH VPA excreted in the urine was low (0.1-0.5% of the dose of VPA and 0.6-1.5% of the dose of 3-OH administered). The amount of 3-keto VPA and glucuronide (VPA-Glu) excreted was marked (5.8-26.2% and 13.1-88.7% of the dose of VPA administered, respectively). The urinary excretion of VPA and its metabolites by patients who have taken a normal amount of a VPA preparation was almost the same as that of healthy volunteers. Two epileptic patients who took a large amount of the VPA preparation showed a high excretion of VPA-Glu without an increase in their plasma VPA-Glu.

Revascularization with split duro-encephalo-synangiosis in the pediatric moyamoya disease--surgical result and clinical outcome.

Dural arteries are potential donor arteries for cortical revascularization. In this report, a technique of indirect anastomosis using a split dura is presented. At surgery, the dura near the branches of the middle meningeal artery was split into outer and inner layers, and the split surface of the outer layer was attached to the cortical surface (split duro-encephalo-synangiosis; split DES). This procedure, combined with standard encephalo-duro-arterio-synangiosis, was applied to 25 hemispheres in 18 patients with pediatric Moyamoya disease (mean age, 6 years). Postoperative superselective angiograms demonstrated effective cortical revascularization through the dural arteries in addition to the supply from the scalp arteries. All the patients were symptom free by 1.5 years after surgery. Postoperative reversible ischemic neurological deficit and infarction were seen in three (12%) and one (4%), respectively. The follow-up period ranged from 1 to 12 years (mean, 6.5 years). Thirteen of 16 (81%) patients led normal lives and three were mildly handicapped due to mental retardation that existed preoperatively. The split DES is a useful technique to extend the area of revascularization of ischemic hemispheres in Moyamoya disease.

Idiopathic cranial pachymeningoencephalitis focally affecting the parietal dura mater and adjacent brain parenchyma: case report.

OBJECTIVE AND IMPORTANCE: Cranial pachymeningitis is a typically diffuse granulomatous disease, which often affects the tentorium and falx. We report a rare case of idiopathic cranial pachymeningoencephalitis focally affecting only the left parietal dura mater and adjacent inferior parietal lobule. CLINICAL PRESENTATION: A 46-year-old woman, with no history of disease, suddenly had a generalized convulsion. A gadolinium-enhanced T1-weighted magnetic resonance image showed homogeneously stained meninges extending to the cortical parenchyma with marked perifocal edema. The thickened dura was visualized as a hypointense area on a T2-weighted magnetic resonance image. INTERVENTION: The patient underwent successful en bloc excision of the mass involving the dura mater and adjacent brain parenchyma. Histological examination of the dura mater revealed large numbers of chronic and acute inflammatory cells. These cells were also present in the subarachnoid and Virchow-Robin spaces and part of the brain parenchyma in the resected cortex. After the operation, the patient experienced no neurological deficits or recurrent mass for 10 months. CONCLUSION: Early diagnosis of pachymeningitis using magnetic resonance imaging is important for the treatment of pachymeningoencephalitis, because diffuse involvement of the dura mater and brain parenchyma can make en bloc excision difficult.

Essential hypertension and neurovascular compression at the ventrolateral medulla oblongata: MR evaluation.

PURPOSE: To investigate, using MR imaging, neurovascular compression at the ventrolateral medulla oblongata in patients with essential hypertension. METHODS: Thirty-two patients with essential hypertension (57.6 +/- 7 years of age), 6 patients with secondary hypertension (56.7 +/- 10.3 years of age), and 18 control subjects (50.5 +/- 11 years of age) were evaluated. Transaxial three-dimensional fast low angle shot images were obtained (38/6/1 [repetition time/echo time/excitations]). The center of a 40-mm-thick slab (16 partitions) was placed at the pontomedullary junction. We evaluated the relationships between the upper ventrolateral medulla and the vertebral arteries and branches identified by their flow-related hyperintensities in each group. RESULTS: In the essential hypertension group, 29 (90.6%) of 32 cases showed neurovascular compression. Of those, 22 demonstrated neurovascular compression on the left side, 3 on both sides, and 4 on the right side. In the control group, 4 cases of 18 showed neurovascular compression. In the secondary hypertension group, 1 of 6 cases showed neurovascular compression. The rates of observed neurovascular compression between controls and essential hypertension group were statistically significant. CONCLUSION: We found a close correlation between essential hypertension and neurovascular compression at the ventrolateral medulla oblongata on the left side. MR with a 3-D fast low-angle shot sequence has acceptable spatial resolution and depicts blood vessels simultaneously by flow-related phenomena.

Apnea associated with Chiari malformation: medullary hemorrhage revealed by MRI.

Medullary hemorrhage in the medulla oblongata of an infant with Chiari malformation, hydrocephalus, meningomyelocele and hypogenesis of the corpus callosum is reported. Four days after placement of a ventriculoperitoneal shunt, spontaneous respiration diminished. Magnetic resonance imaging (MRI) successfully revealed a small medullary hemorrhage.

Measurement of labeling index of DNA polymerase alpha in human brain tumors. Comparative study with labeling indices of BUdR in vitro and Ki-67.

Proliferative activity of 28 human brain tumors was estimated by simultaneous measurement of DNA polymerase alpha, Ki-67 and bromodeoxyuridine (BUdR) labeling indices on microscopic tissue preparations stained immunologically with monoclonal antibodies using a peroxidase technique. All the antigens were exclusively found in the nucleus. The labeling index of BUdR was lower than those of the other indicators. The values of the DNA polymerase alpha labeling index were almost the same as those of the Ki-67 labeling index. Simultaneous measurement of these parameters may provide more useful information on tumor cell growth kinetics than that of a single parameter.

Malignant meningioma metastasizing through the cerebrospinal pathway.

A case of malignant meningioma metastasizing through the cerebrospinal pathway is presented. The primary tumor was a parasagittal malignant meningioma invading into the brain. The tumor seeded to the cerebellopontine angle cistern and thoracic spine after multiple operations. Although this type of tumor borders the CSF, metastasis through the cerebrospinal pathway is rare, and only 18 such cases have been reported (2, 3, 10, 12).

True posterior communicating artery aneurysm.

Two rare cases of true posterior communicating artery aneurysm are reported. One case was a saccular aneurysm, which was successfully clipped. The other was a case of fusiform trapped aneurysm, and hemiparesis and oculomotor palsy appeared transiently after surgery. In general, this type of aneurysm is included in the category of internal carotid-posterior communicating aneurysm, although some special considerations are necessary in surgical treatment.

Correlation of in vitro bromodeoxyuridine labeling index and DNA aneuploidy with survival or recurrence in brain-tumor patients.

There are no previous reports correlating the in vitro bromodeoxyuridine (BUdR) labeling index (LI) with the clinical outcome in patients with brain tumors. The reliability of the LI as a predictor of patient survival or recurrence was examined in this study of 66 human brain tumors (19 gliomas, 18 meningiomas, and 29 others). Anti-BUdR staining was performed on surgically extirpated tumor tissue that had been treated with BUdR as previously described. Correlation of the BUdR LI with patient survival or tumor recurrence rate was carried out by the method of Kaplan and Meier. Deoxyribonucleic acid (DNA) aneuploidy was estimated in 52 cases. The results of this study indicate that BUdR LI values correlated well with the clinical course of patients with brain tumor. In comparison with patients with higher LI's, there was both a significantly higher survival rate for tumors other than meningiomas and a higher recurrence-free rate for meningiomas in patients with LI's of less than 4% and 1%, respectively. Although there was a tendency for patients without tumor aneuploidy to show better survival data than the others, no statistical difference was observed. These results suggest that the in vitro BUdR labeling method is reliable for prediction of a patient's prognosis, whereas prognosis on the basis of DNA aneuploidy alone is uncertain.

Cerebral sparganosis mansoni. Report of two cases.

Among diseases due to cerebral parasitism, that caused by Sparganum mansoni, the larva of Spirometra mansoni, is very rare. We have encountered two such cases. A computed tomography scan in both revealed a nodular high density contrast enhanced area against an extensive low density background area. Neither calcification nor cyst formation was recognized. These computed tomography scan findings were thought to be characteristic for cerebral sparganosis mansoni and were difficult to differentiate from those of a cerebral tumor. In both cases, definitive diagnosis was achieved by identification of the worm after excision of the lesion. The best treatment for cerebral sparganosis mansoni is surgical excision of the lesion, and in the two cases presented the postoperative outcome was good.