Background and Purpose-Proportions of patients with single and multiple aneurysms among patients suffering from subarachnoid hemorrhage (SAH) are not well established. We evaluated these proportions and the differences in outcome between SAH patients with a single aneurysm and those with multiple aneurysms in a defined population. Methods- Between 1989Between and 1998Between , 2037 to 89 years) with ruptured intracranial aneurysm were treated in 11 hospitals in Nagasaki Prefecture. Multiple aneurysms were found in 361 of these patients. Age-and sex-specific incidences of ruptured aneurysm per 100 000 people were calculated. Results-For both single and multiple aneurysms, the incidences were significantly higher in women than in men 60 to 69 and 70 to 79 years of age. In every age category except 80 to 89 years, the frequency of multiple aneurysms was higher in women than in men. The overall frequency of multiple aneurysms was 20.2% in women, which was significantly higher than the 12.4% in men (PϽ0.0001). In patients 70 to 89 years of age, outcome was significantly worse (in terms of surgical complications) in patients with multiple aneurysms (12.1%) than in patients with a single aneurysm (6.0%). Conclusions-Among all patients with SAH, women Ն50 years of age outnumber other age and sex categories. Female sex itself is also associated with an increased rate of multiple aneurysms among SAH patients. Among the elderly Ն70 years of age, prognosis is less favorable for SAH patients with multiple aneurysms than for those with a single aneurysm.

The purpose of this study was to clarify the efficacy of single-voxel proton magnetic resonance spectroscopy (MRS) in differentiating high-grade glioma from metastasis. Thirty-one high-grade gliomas (11 anaplastic gliomas and 20 glioblastomas) and 25 metastases were studied. Proton MRS was performed using point-resolved spectroscopy with echo times (TEs) of both 136 and 30 ms. The peaks for lipid were evaluated at short TE, and those for N-acetyl-aspartate (NAA), creatine (Cr), and choline-containing compounds (Cho) were assessed at long TE. All the tumors exhibited a strong Cho peak at long TE. Twenty-one of 25 metastases showed no definite Cr peak. The remaining 4 metastases showed NAA and Cr peaks; however, the presence of NAA and relatively high NAA/Cr ratio (1.58+/-0.56) indicated normal brain contamination. All the gliomas, except for a single glioblastoma, showed a Cr peak with (n=16) or without (n=14) NAA. At short TE all metastases and glioblastomas showed definite lipid or lipid/lactate mixture, but anaplastic gliomas showed no definite lipid signal. Intratumoral Cr suggests glioma. Absence of Cr indicates metastasis. Definite lipid signal indicates cellular necrosis in glioblastoma and metastasis, and no lipid signal may exclude metastases.

Volume measurement on 3D-SPGR MR imaging was a suitable method to assess tumor changes. Volume changes beyond twofold or continuous enlargement for longer than 2 years after radiosurgery are key criteria in rating the effects of radiation. Some cases of hydrocephalus after radiosurgery resolved spontaneously and their rates of occurrence were similar to the typical incidence of hydrocephalus associated with VS.

Accurate neuroimaging grading of gliomas is useful for management, but techniques such as MRI and CT are not sufficiently reliable. Necrosis is a consistent, decisive prognostic factor and the key diagnostic criterion for glioblastoma multiforme. MR spectroscopy (MRS) allows noninvasive measurement of metabolites in brain tumours and mobile lipids reflect necrosis. However, short echo-time (TE) spectroscopy has been required for reliable assessment of lipids, since their relaxation times are very short. Recent advances have made it possible to perform short-TE MRS. We attempted to evaluate the significance of short TE spectroscopy as part of routine imaging for diagnosis and grading of gliomas. We performed TE 30 ms MRS in 25 patients with gliomas (grade II six; grade III three; grade IV, 16) and in 19 areas of healthy white matter using proton brain examination/single voxel (PROBE/SV) and point-resolved spatially localised spectroscopy (PRESS). With short-TE spectroscopy, lipid signals were detected in all 16 tumours of grade IV, one grade II (P = 0.0002) and none of grade III (P = 0.001). TE 136 ms MRS, carried out in 20 of these cases, showed lipid signals in only four of 14 grade IV tumours and in none of the other six. N-acetylaspartate/choline (NAA/Cho) ratios were always more than 1.0 in healthy tissues and less than 1.0 in all but one of the gliomas. The mean creatine (Cr)/Cho ratio in each tumour grade was significantly lower than in the healthy tissues. The mean Cr/Cho ratio was also significantly lower in grade IV than in grade II tumours (P < .0005). Considerable overlap in Cr/Cho ratio was observed between grade II and grades III and IV gliomas at long but less so at short-TE MRS. We conclude that short-TE MRS with PROBE/SV and PRESS is of value in grading gliomas.

Drug resistance is one of the important factors that determine tumor response to chemotherapy. Several candidates for resistance to various chemotherapeutic agents have been elucidated. O6-methylguanine-DNA methyltransferase (MGMT) removes methylation damage induced by nitrosourea from the O6 position of DNA guanines before cell injury. Glutathione-S-transferase (GST) pi is also involved in nitrosourea resistance. We examined the expression of MGMT and GST pi in 18 glioblastomas (GBM) using immunohistochemistry and compared the results with patients' survival after administration of 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU)-based chemotherapy. According to the Kaplan-Meier's method, although median progression free survival (PFS) of eight patients whose tumors retained high MGMT (3+ approximately 2+), and 10 patients whose tumors showed low MGMT expression (1+ approximately 0) were nine and 15 months, respectively (p = 0.09), median overall survival (OS) of the two groups were 12 and 22 months, respectively, which were significantly different (p = 0.01). GST pi expression in GBM was not a prognostic factor. It is suggested that GBM with strong staining of MGMT activity may show more resistance to ACNU-based chemotherapy compared to that with low MGMT. The simple immunohistochemical analysis of MGMT in GBM can be a useful method to determine whether ACNU or another treatment regimen should be recommended.

The authors report three cases of progressive vasogenic brain edema surrounding a cerebral aneurysm after endovascular coil embolization. In all three cases embolization was incomplete due to the aneurysms' large sizes and wide necks. Follow-up magnetic resonance imaging revealed de novo vasogenic brain edema surrounding the aneurysms 3 to 6 months after the initial treatment. The edema progressed in parallel with regrowth of the aneurysms. All three aneurysms were deep in the brain parenchyma and showed intramural enhancement, suggesting hemorrhage or inflammation. Each patient underwent a second embolization for the aneurysm regrowth, which resulted in improvement of the edema. Based on the findings in these cases and review of the literature, it is suggested that incomplete occlusion of larger aneurysms that are deep within the brain may lead to a disorganized intraluminal thrombosis, aneurysm pulsing, and intramural hemorrhage or inflammation, all of which are associated with brain edema following aneurysm recanalization and regrowth. It should be kept in mind that incomplete embolization of larger aneurysms may cause such malignant change and that this complication may occur after endovascular treatment.

Background and Purpose-To increase the reliability of 99m Tc-hexamethyl propyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) study in the evaluation of hemodynamic change with balloon test occlusion (BTO) of the internal carotid artery, we attempted to clarify the usefulness of additional monitoring of regional oxygen saturation of the brain (rSO 2 ). Methods-During BTO, rSO 2 monitoring with transcranial near infrared spectroscopy was performed 17 times on 16 patients. Asymmetrical distribution of the tracer was classified visually as follows: group 1, little or no asymmetry, and group 2, moderate or severe asymmetry. Seven regions of interest (ROI) were defined in the middle cerebral artery area of each hemisphere, and the asymmetry index (AI)ϭ200ϫ(C non ϪC occl )/(C non ϩC occl) ), where C non ϭmean counts on the nonoccluded side, and C occl ϭmean counts on the occluded side were also calculated. Then, mean AI (MAI) was obtained from AI of 7 ROIs for each study. Results-Of the 17 procedures, 10 BTOs were in group 1 and 5 BTOs were in group 2. Two patients did not undergo SPECT study because of the immediate appearance of a neurological deficit with BTO; they were defined as group 3. The MAI in group 1 was 2.6Ϯ3.3%, which was significantly smaller than the MAI in group 2 (25.6Ϯ5.0%, PϽ0.02).The ⌬rSO 2 (baseline rSO 2 ϪrSO 2 during ICA occlusion) with BTO in group 1 was 1.5Ϯ1.4% (nϭ10), which was statistically smaller than that in group 2 (5.5Ϯ1.3%, nϭ4, PϽ0.05). The ⌬rSO 2 in group 3 was 9.0Ϯ0.0% (nϭ2). In group 1, however, rSO 2 began to decline when the stump pressure fell to 45 mm Hg and always declined when the stump pressure fell below 40 mm Hg. Furthermore, in group 1, a significant correlation was observed between the ⌬rSO 2 and stump pressure (rϭ0.85, PϽ0.0001). Conclusions-This preliminary study reveals that an obvious asymmetrical SPECT pattern always accompanies a profound decrease in rSO 2 and that rSO 2 parallels a severe reduction in stump pressure in cases exhibiting a symmetrical SPECT pattern. Thus, the cerebral oximetry sensitively reflects the cerebral oxygenation, and simultaneous measurements of rSO 2 and stump pressure with 99m Tc-HMPAO SPECT study apparently are useful in evaluating hemodynamic integrity with BTO. (Stroke. 1999;30:407-413.)

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