Treatment outcomes in glioblastoma patients aged 76 years or older: a multicenter retrospective cohort study.

Age is one of the most important prognostic factors in glioblastoma patients, but no standard treatment has been established for elderly patients with this condition. We therefore conducted a retrospective cohort study to evaluate treatment regimens and outcomes in elderly glioblastoma patients. The study population consisted of 79 glioblastoma patients aged ≥ 76 years (median age 78.0 years; 34 men and 45 women). The median preoperative Karnofsky performance status (KPS) score was 60. Surgical procedures were classified as biopsy (31 patients, 39.2 %), <95 % resection of the tumor (21 patients, 26.9 %), and ≥ 95 % resection of the tumor (26 patients, 33.3 %). Sixty-seven patients (81.0 %) received radiotherapy and 45 patients (57.0 %) received chemotherapy. The median overall progression-free survival time was 6.8 months, and the median overall survival time was 9.8 months. Patients aged ≥ 78 years were significantly less likely to receive radiotherapy (p = 0.004). Patients with a postoperative KPS score of ≥ 60 were significantly more likely to receive maintenance chemotherapy (p = 0.008). Multivariate analyses identified two independent prognostic factors: postoperative KPS score ≥ 60 (hazard ratio [HR] = 0.531, 95 % confidence interval [CI] 0.315-0.894, p = 0.017) and temozolomide therapy (HR = 0.442, 95 % CI 0.25-0.784, p < 0.001).The findings of this study suggest that postoperative KPS score is an important prognostic factor for glioblastoma patients aged ≥ 76 years, and that these patients may benefit from temozolomide therapy.

Cilostazol for the prevention of acute progressing stroke: a multicenter, randomized controlled trial.

BACKGROUND: Progressing stroke is one of the major determinants of outcome after acute ischemic stroke. A pilot randomized controlled trial was conducted to investigate the effect of cilostazol on progressing stroke. METHODS: Adult patients with noncardioembolic ischemic stroke within 24 hours after onset were randomized to receive cilostazol 200 mg/day (cilostazol group) or no medication (control group) in addition to the optimum medical treatments (a free radical scavenger plus an antiplatelet agent or an antithrombin agent). The primary endpoints were the rate of progressing stroke, defined as aggravation of the National Institutes of Health Stroke Scale (NIHSS) score by ≥ 4 points on days 3 and/or 5 and a modified Rankin Scale score of 0 to 1 at 3 months after enrollment. Aggravation caused by systemic complications, edema, hemorrhagic infarction, or recurrent stroke was not considered as progressing stroke. This trial was registered as UMIN000001630. RESULTS: A total of 510 patients were enrolled from 55 institutions in Japan between February 2009 and July 2010. The rate of progressing stroke was 3.2% and 6.3% in the cilostazol and control groups, respectively (P = .143). The modified Rankin Scale score of 0 to 1 at 3 months did not differ between the groups. CONCLUSIONS: Cilostazol failed to show a preventive effect against acute progressing stroke. However, the tendency to reduce progressing stroke and the results of stratified analyses may encourage additional studies to clarify the effect of cilostazol in the treatment of acute ischemic stroke.

[Cerebellar hemangioblastoma with marked pleomorphism: a case report].

We reported an extremely rare case of cerebellar hemangioblastoma with marked pleomorphism and reviewed the literature. A 68-year-old male presented with a one-month history of headache and vomiting. Neurological examination revealed right-sided dysmetria and truncal ataxia. Contrast-enhanced T1-weighted MR imaging revealed a heterogeneously enhancing tumor with solid and cystic components in the right cerebellum. The solid portion of the tumor was low intensity on diffusion-weighted imaging and low intensity on susceptibility-weighted imaging. 18F-fluorodeoxyglucose PET showed low uptake in the cerebellar tumor and the whole body examination was negative for malignancy. Vertebral angiogram demonstrated moderate tumor staining and no early filling veins. The patient underwent total removal of the tumor through suboccipital craniotomy. Microscopically, the solid tumor contained a cellular rich component consisting of stromal cells and a markedly pleomorphic component including atypical and multinucleated giant cells. The MIB-1 positive rate was 8.2%, which was slightly higher compared to that of hemangioblastomas. We observed strong staining for inhibin-α, aquaporin 1 and neuron specific enolase (NSE) in the tumor cells. PAX-2, cytokeratin and epithelial membrane antigen (EMA) were completely negative in the tumor cells, whereas the tumor cells demonstrated focal staining for CD10. The histological diagnosis was hemangioblastoma. Follow-up MR images showed no evidence of recurrent tumor 14 months after the resection. The study using a combination of immunohistochemical markers (e.g. inhibin-α, aquaporin 1 and PAX-2) is useful for differential diagnosis of hemangioblastoma from metastatic renal cell carcinoma.

Association of stem cell marker CD133 expression with dissemination of glioblastomas.

Dissemination of glioblastoma was once considered rare but is now increasingly encountered with longer survival of glioblastoma patients. Despite the potential negative impact of dissemination on clinical outcome, however, molecular markers useful for prediction of dissemination risk still remains ill defined. We tested in this study for an association between the expression of stem cell marker CD133 and the risk of dissemination in 26 cases of glioblastoma (16 with dissemination and 10 without dissemination). The protein expression of CD133 was examined by western blot analysis of tumor specimens, and the CD133 expression levels were quantified by densitometry and normalized to beta-actin. The results indicated that CD133 expression levels are significantly higher in glioblastomas with dissemination (mean 10.3, range 0.20-27.8) than in those without (mean 1.18, range 0.07-3.58). The results suggest that CD133 could be a molecular predictor of glioblastoma dissemination, and also give rise to an intriguing idea that CD133-positive cancer stem cells may be implicated in the initiation of disseminated lesions.

Long term outcome and adjacent disc degeneration after anterior cervical discectomy and fusion with titanium cylindrical cages.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is widely performed for the treatment of cervical spinal degenerative disease. Autogenic or allogenic bone grafts are used for interbody fusion with satisfactory long term outcomes. However, harvest of the autograft causes donor site complications and allograft is associated with low fusion rate. Threaded titanium cages (TC) have recently been introduced to cope with these disadvantages, but there is little evidence of long term results. METHODS: The long term outcome was studied after ACDF using TC. Clinical and imaging follow up was performed in 41 patients for at least 5 years (range 5-8.3 years). New computer-assisted measurement methods for radiographs are proposed. FINDINGS: ACDF with TC achieved 80% excellent or good outcome by Odom's criteria, 95% fusion rate, and few minor complications. Asymptomatic adjacent disc degeneration was detected in 50% of the patients by our measurement methods. However, symptomatic adjacent disc degeneration occurred in 5% of the patients and only 2% required additional surgery. CONCLUSIONS: These results are comparable or better than those after ACDF with autograft or allograft. ACDF with TC can achieve rigid fixation and provide good long term results.

Model mice for mild-form glycine encephalopathy: behavioral and biochemical characterizations and efficacy of antagonists for the glycine binding site of N-methyl D-aspartate receptor.

Glycine encephalopathy (GE) is caused by an inherited deficiency of the glycine cleavage system (GCS) and characterized by accumulation of glycine in body fluids and various neurologic symptoms. Coma and convulsions develop in neonates in typical GE while psychomotor retardation and behavioral abnormalities in infancy and childhood are observed in mild GE. Recently, we have established a transgenic mouse line (low-GCS) with reduced GCS activity (29% of wild-type (WT) C57BL/6) and accumulation of glycine in the brain (Stroke, 2007; 38:2157). The purpose of the present study is to characterize behavioral features of the low-GCS mouse as a model of mild GE. Two other transgenic mouse lines were also analyzed: high-GCS mice with elevated GCS activity and low-GCS-2 mice with reduced GCS activity. As compared with controls, low-GCS mice manifested increased seizure susceptibility, aggressiveness and anxiety-like activity, which resembled abnormal behaviors reported in mild GE, whereas high-GCS mice were less sensitive to seizures, hypoactive and less anxious. Antagonists for the glycine-binding site of the N-methyl-D-aspartate receptor significantly ameliorated elevated locomotor activity and seizure susceptibility in the low-GCS mice. Our results suggest the usefulness of low-GCS mice as a mouse model for mild GE and a novel therapeutic strategy.

Negative pressure pulmonary edema following foramen magnum decompression for Chiari malformation type I.

A 57-year-old obese female presented with vagal and hypoglossal nerve pareses, and magnetic resonance imaging revealed Chiari malformation type I. Standard surgical treatment for Chiari malformation type I was successfully performed. However, immediately after the patient was extubated, she developed signs of upper airway obstruction and chest radiography revealed pulmonary edema. Her ventilation was assisted by maintaining positive end-expiratory pressure at 8 cmH2O. Intravenous furosemide and hydrocortisone were administered. Her respiratory status improved 12 hours later, and she was extubated 3 days after the operation. Postextubational course was uneventful, and the patient was discharged 2 weeks after extubation. The initial neurological deficits had mostly disappeared by 10 months after the operation. This unusual case of negative pressure pulmonary edema indicates that obesity and lower cranial nerve paresis are further risk factors for pulmonary edema as a postextubational complication of surgical treatment.

Direct correlation between ischemic injury and extracellular glycine concentration in mice with genetically altered activities of the glycine cleavage multienzyme system.

BACKGROUND AND PURPOSE: Ischemia elicits the rapid release of various amino acid neurotransmitters. A glutamate surge activates N-methyl-d-aspartate (NMDA) glutamate receptors, triggering deleterious processes in neurons. Although glycine is a coagonist of the NMDA receptor, the effect of extracellular glycine concentration on ischemic injury remains controversial. To approach this issue, we examined ischemic injury in mice with genetically altered activities of the glycine cleavage multienzyme system (GCS), which plays a fundamental role in maintaining extracellular glycine concentration. METHODS: A mouse line with increased GCS activity (340% of C57BL/6 control mice) was generated by transgenic expression of glycine decarboxylase, a key GCS component (high-GCS mice). Another mouse line with reduced GCS activity (29% of controls) was established by transgenic expression of a dominant-negative mutant of glycine decarboxylase (low-GCS mice). We examined neuronal injury after transient occlusion of the middle cerebral artery in these mice by measuring extracellular amino acid concentrations in microdialysates. RESULTS: High-GCS and low-GCS mice had significantly lower and higher basal concentrations of extracellular glycine than did controls, respectively. In low-GCS mice, the extracellular glycine concentration reached 2-fold of control levels during ischemia, and infarct volume was significantly increased by 69% with respect to controls. In contrast, high-GCS mice had a significantly smaller infarct volume (by 21%). No significant difference was observed in extracellular glutamate concentrations throughout the experiments. An antagonist for the NMDA glycine site, SM-31900, attenuated infarct size, suggesting that glycine operated via the NMDA receptor. CONCLUSIONS: There is a direct correlation between ischemic injury and extracellular glycine concentration maintained by the GCS.

(99m)Tc-MIBI imaging for prediction of therapeutic effects of second-generation MDR1 inhibitors in malignant brain tumors.

The aim of this study was to explore whether (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) is suitable to elucidate multidrug resistance and prediction of potentiation of antitumor agents by second-generation MDR1 inhibitors (PSC833, MS-209) in malignant brain tumors in rat. Malignant tumor cells (RG2 and C6 gliomas, Walker 256 carcinoma) were incubated with low dose vincristine (VCR) to induce multidrug resistance. MTT assay demonstrated a significant increase of surviving fractions in VCR-resistant sublines compared to those of drug-naive cells. Reverse transcriptase polymerase chain reaction revealed higher expression of MDR1 mRNA in VCR-resistant cells than drug-naive cells in each line. Volume distribution (V(d)) of (99m)Tc-MIBI was negatively correlated with MDR1 mRNA expression among drug-naive and VCR-resistant cells. MDR1 inhibitors decreased surviving fractions and increased V(d) of (99m)Tc-MIBI significantly in VCR-resistant sublines, whereas MDR1 mRNA expression was unchanged. These findings indicate that (99m)Tc-MIBI efflux was functionally suppressed by MDR1 inhibitors. Autoradiographic images of (99m)Tc-MIBI revealed higher uptake in drug-naive cells at basal ganglia compared with VCR-resistant cells at the opposite basal ganglia of rats. Oral administration of the second-generation MDR1 inhibitors significantly increased (99m)Tc-MIBI accumulation of both tumors. Therapeutic effects of VCR with or without the MDR1 inhibitors were also evaluated autoradiographically using (14)C-methyl-L-methionine ((14)C-Met) and MIB-5 index. (14)C-Met uptake and MIB-5 index of both tumors treated with VCR following the MDR1 inhibitor treatment significantly decreased compared with tumors treated with VCR alone. Analysis of (99m)Tc-MIBI accumulation is considered informative for detecting MDR1-mediated drug resistance and for monitoring the therapeutic effects of MDR1 inhibitors in malignant brain tumors.

Angiographically occult spinal dural arteriovenous fistula located using selective computed tomography angiography. Case report.

Spinal dural arteriovenous fistula (DAVF) is the most common type of spinal arteriovenous malformation and may cause progressive myelopathy but is usually treatable in the early stages by direct surgery or intravascular embolization. Selective spinal angiography has been the gold standard for diagnosis, but angiographically occult DAVF is not uncommon. A 67-year-old man presented with a 2-year history of progressive paraparesis. Magnetic resonance (MR) imaging demonstrated segmental atrophy of the spinal cord and dilated coronary veins on the dorsal surface of the spinal cord. A DAVF was suspected, but repeated selective angiography failed to demonstrate the fistula. Findings from spoiled gradient echo MR imaging suggested that the draining vein flowed into the dilated venous plexus at the T-9 level. Selective computed tomography (CT) angiography of the right T-9 intercostal artery confirmed the location of the fistula. The authors successfully occluded the draining vein through surgery, and they observed that the fistula was low flow. The patient exhibited improvement in his symptoms, and postoperative MR imaging confirmed closure of the fistula. Selective CT angiography is useful in locating the draining vein of angiographically occult DAVF and therefore minimizing the extent of the surgical procedure.

Candesartan reduces superoxide production after global cerebral ischemia.

Excessive superoxide production after cerebral ischemia is known to mediate neuronal injury. Angiotensin II type 1 receptor activation results in production of superoxide, but whether angiotensin II type 1 receptor blockade prevents production of superoxide and subsequent neuronal injury after ischemia remains unclear. Normotensive rats received the angiotensin II type 1 receptor blocker, candesartan or only vehicle before induction of global cerebral ischemia. Approximately 30% of the hippocampal CA1 neurons survived in candesartan-treated animals, whereas only 2% of neurons survived in vehicle-treated animals. Superoxide production was significantly less in these vulnerable neurons in candesartan-treated animals than in vehicle-treated animals. Angiotensin II type 1 receptor may have an essential role in superoxide production and subsequent injury in vulnerable neurons after global cerebral ischemia.

Comparison of technetium Tc 99m hexamethylpropyleneamine oxime single-photon emission tomograph with stump pressure during the balloon occlusion test of the internal carotid artery.

BACKGROUND AND PURPOSE: Measuring blood pressure (stump pressure) in the distal internal carotid artery during occlusion of the internal carotid artery is reportedly a reliable safety index with which to predict ischemia following permanent occlusion of the internal carotid artery. We compared the stump pressure during occlusion of the internal carotid artery with single-photon emission CT (SPECT) using technetium Tc 99m hexamethylpropyleneamine oxime (HMPAO). METHODS: Twenty-seven patients underwent the balloon occlusion test. After occlusion of the internal carotid artery was performed by a balloon catheter, technetium Tc 99m HMPAO was injected, and then the balloon remained inflated for 15 minutes. The stump pressure was continuously monitored for those 15 minutes. After the balloon catheter was deflated and removed, SPECT was performed. Sixty-four symmetric pairs of regions of interest were set on both sides of the cerebral hemisphere. The radioactivity count ratio (L/n ratio) of the occluded side to the contralateral normal side was calculated. We defined hypoperfusion as an area with an L/n ratio <0.8. The minimum mean stump pressure (minMSP) during the balloon occlusion test and the pressure ratio of the minMSP to the mean systemic pressure were compared with the hypoperfusion area on SPECT. RESULTS: The number of regions of interest with hypoperfusion was significantly (P < .001) greater in patients with a minMSP <40 mm Hg (mean [+/-SD] = 31.5 +/- 13.7) than in patients with a minMSP > or =40 mm Hg (5.1 +/- 4.0). The number of regions of interest with hypoperfusion was also significantly (P < .001) greater in patients with a pressure ratio <0.5 (26.7 +/- 15.8) than in patients with a pressure ratio > or =0.5 (4.5 +/- 3.5). CONCLUSION: The minMSP during the balloon test occlusion reflects the extent of the hypoperfused area measured by SPECT using technetium Tc 99m HMPAO.

Thallium-201 SPECT in the evaluation of early effects on brain tumors treated with stereotactic irradiation.

PURPOSE: To determine whether thallium-201 SPECT can predict response to stereotactic irradiation (STI) earlier than magnetic resonance imaging (MRI), the change in tumor size measured by MRI was compared with the change in tumor activity measured by Tl-201 SPECT before and after STI. MATERIALS AND METHODS: Twenty-one tumors in 16 patients with intracranial tumors were treated by STI. Tl-201 SPECT was performed within 1 week before the beginning of STI and within 1 week after the end of STI in all patients. All patients underwent MRI within 1 week before the beginning of STI, and 14 patients (19 tumors) underwent MRI within 1 week after the end of STI. Follow-up MRI was performed 1 to 2 months after the end of STI in 14 patients (16 tumors). The activity of Tl-201 in the tumor divided by that of the uninvolved symmetric area was defined as the Tl-index. The change in tumor size immediately and 1 to 2 months after STI was compared with the change in Tl-index immediately after STI. RESULTS: No significant relationship between the ratio of tumor size immediately after STI and the ratio of Tl-index immediately after STI was found. A significant correlation (r = 0.69, P <0.05) between the ratio of tumor size 1 to 2 months after STI and the ratio of Tl-index immediately after STI was found. CONCLUSIONS: This study suggests that Tl-201 SPECT immediately after STI can predict treatment response 1 to 2 months after STI, and that Tl-201 SPECT can be an early indicator of treatment response.

[Four cases of spontaneous spinal epidural hematoma].

Spontaneous spinal epidural hematoma (SSEH) is a rare clinical entity. Although approximately 500 cases have been reported, controversy exists concerning timing of the treatment and the validity of decompression surgery. We recently encountered four cases of SSEH. Evacuation of the hematoma was carried out in two patients with severe or persistent neurological deficits. Other two patients were treated conservatively because of the rapid resolution of the symptoms. All four patients improved after the treatment; three patients fully recovered and one patient required rehabilitation for moderate quadriparesis. Many previous reports recommended decompression surgery within 48 hours after the onset, however, one patient in our series fully recovered after surgery 4 days after the onset. We reviewed 183 operative cases of SSEH with incomplete neurological deficits in the literature and found that 93% of the patients who underwent surgery more than 48 hours after symptom onset showed good neurological recovery. Conservative treatment should be undertaken for rapidly improving patients, but surgical intervention should be considered in symptomatic patients regardless of the time from the onset.

Amino acid PET tracers are reliable markers of treatment responses to single-agent or combination therapies including temozolomide, interferon-ß, and/or bevacizumab for glioblastoma.

INTRODUCTION: We examined whether the amino acid PET tracers, trans-1-amino-3-(18)F-fluorocyclobutanecarboxylic acid (anti-(18)F-FACBC) and (11)C-methyl-l-methionine ((11)C-Met), are suitable for detecting early responses to combination therapies including temozolomide (TMZ), interferon-ß (IFN), and bevacizumab (Bev) in glioblastoma. METHODS: Human glioblastoma U87MG (U87) cells were incubated with low dose TMZ to induce chemoresistance. Both trans-1-amino-3-fluoro-1-(14)C-cyclobutanecarboxylic acid (anti-(14)C-FACBC) and (3)H-methyl-l-methionine ((3)H-Met) uptake were quantified using triple-label accumulation assays to examine the relationship between tracer uptake and proliferation ((3)H-thymidine (TdR) accumulation) in vitro. U87 and U87R (TMZ-resistant subculture) cells were inoculated into the right and left basal ganglia, respectively, of F344/N-rnu rats. The efficacy of single-agent (TMZ, Bev) and combination therapy (TMZ/IFN, TMZ/Bev, TMZ/IFN/Bev) was examined in orthotopic gliomas using MRI, Evans blue extravasation, anti-(14)C-FACBC, and (3)H-Met autoradiography, and MIB-1 immunostaining. RESULTS: TMZ treatment decreased (3)H-TdR accumulation and the volume distribution of anti-(14)C-FACBC and (3)H-Met in U87 but not U87R cells. TMZ/IFN combination therapy significantly decreased these parameters in U87R cells; however, Bev had no additional effect in vitro. In vivo, U87R-derived gliomas were observed as equivocal tumors on MRI and T2-high intensity lesions. Bev treatment, either alone or in combination, markedly decreased U87 enhancing lesions. By contrast, autoradiographic images using anti-(14)C-FACBC and (3)H-Met clearly delineated tumor extent, which spread widely beyond T2-high intensity lesions and enhancing lesions. TMZ therapy significantly decreased tracer accumulation and proliferation of U87- but not U87R-derived tumors. TMZ/IFN combination treatment significantly decreased these parameters in U87R tumors, which were further reduced (in both tumor types) by Bev addition. Tracer uptake correlated with the MIB-1 proliferation index. However, MRI was unsuitable for tumor delineation and assessment of Bev treatment response. CONCLUSIONS: Triple-agent therapy (TMZ/IFN/Bev) was effective against even TMZ-resistant glioblastomas. PET with amino acid tracers provides useful information on the early response of glioblastomas to single-agent and combination therapy.

Induction of heat shock protein 40 and GrpE mRNAs following transient focal cerebral ischemia in the rat.

Cerebral ischemia is associated with the induction of several heat shock proteins (HSPs), but the effects on HSP40 and GrpE are less clear. The present study investigated the induction of Hsp40 and GrpE mRNAs following 30 min of middle cerebral artery occlusion in the rat model. Reverse transcription-polymerase chain reaction (PCR) and in situ hybridization analyses showed significant induction of both mRNAs in the ischemic cortex. These results demonstrate the synergic induction of HSP70 molecular chaperone machinery in cerebral ischemia.

Medulloblastoma with extensive nodularity: single photon emission CT study with iodine-123 metaiodobenzylguanidine.

We present the case of an infant with medulloblastoma with extensive nodularity, which had been called cerebellar neuroblastoma. MR imaging clearly revealed a nodular enhancement, which appeared as a grape-like lesion. Single photon emission CT revealed markedly high iodine-123 metaiodobenzylguanidine uptake in the enhancing tumor. Iodine-123 metaiodobenzylguanidine single photon emission CT may be useful in the diagnosis of medulloblastoma with extensive nodularity, which has been considered to be a subgroup of medulloblastoma with extensive neuronal differentiation.

Simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery aneurysms.

OBJECT: The authors of this study evaluated the efficacy of simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery (ICA) aneurysms. METHODS: The endoscopic technique was applied during microsurgery in 11 patients with 13 aneurysms. Nine of these lesions were located on the posterior communicating artery (PCoA), three in the paraclinoid region, and one on the anterior choroidal artery (AChA). Eight patients had unruptured aneurysms and three had ruptured aneurysms. The endoscope was introduced after first exposing the aneurysm through the microscope and was gripped firmly by an airlocked holding arm fitted with a steering system throughout the entire surgery, including dissection of the perforating arteries and application of the aneurysm clips. Regarding paraclinoid aneurysms, clips were applied through direct visualization of the ophthalmic artery and the proximal neck. In a case involving a superior hypophyseal artery aneurysm in the paraclinoid segment, a ring clip was applied without removing the bone structure around the optic canal. In all aneurysms of the PCoA and the AChA, perforating arteries behind the lesion were identified and dissected using endoscopic control. The aneurysm clip was applied in the best position in a single attempt in 10 of 11 patients. There was no surgical complication related to the endoscopic procedures. CONCLUSIONS: Simultaneous monitoring with the microscope and endoscope is extremely useful in applying clips to ICA aneurysms. This combined method allows for direct dissection of the aneurysm, perforating vessels, and the main trunk in an area not visible through the microscope's eyepiece and promises better surgical results.

Endoscope-assisted clipping of a superior hypophyseal artery aneurysm without removal of the anterior clinoid process. Case report.

A 47-year-old man presented with a superior hypophyseal artery aneurysm and an ipsilateral posterior communicating artery aneurysm. Both lesions were successfully clipped without removal of the anterior clinoid process or retraction of the optic nerve by using endoscopic guidance. The endoscope was introduced into the prechiasmatic cistern and provided a clear visual field around the aneurysm that could not be seen via the operating microscope. The endoscope was useful in the identification of the medially projecting lesion and the small perforating branches of the ophthalmic segment of the internal carotid artery. A fenestrated clip could be introduced around the neck of the aneurysm and placed in the best position under endoscopic guidance. Endoscopy-assisted clipping is potentially a very useful procedure for aneurysm surgery.