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Background: Whether a difference in morphology of the infratentorial space is associated with hemifacial spasm is not well understood. The aim of this study was to analyze the three-dimensional conformation of the infratentorial space and evaluate any possible contribution of morphological characteristics to the development of neurovascular compression leading to hemifacial spasm., Methods: We enrolled 25 patients with hemifacial spasm and matched them by age and sex to controls. The extent of the three-dimensional axes and the volume of the infratentorial space were measured using image analysis software for three-dimensional MRI. We evaluated the correlation between a morphological difference in the infratentorial space and changes in vascular configuration in the brain stem., Results: We found no statistical difference in volumetric analyses. The mean aspect ratio on the coronal plane (the ratio of the Z to X extent) of the infratentorial space in patients with hemifacial spasm was significantly lower (p < 0.01) than that in controls, as was the mean aspect ratio on the sagittal plane (the ratio of Z to Y extent, p < 0.01). A smaller sagittal aspect ratio was correlated (p < 0.05) with greater lateral deviation of the basilar artery., Conclusions: Our results suggest that flatness of the superior-inferior dimension of the infratentorial space is an anatomical feature that characterizes patients with hemifacial spasm. We hypothesize that this unique structural variation may exaggerate the lateral deviation of the vertebrobasilar arteries due to arteriosclerosis and exacerbate the space competition among vessels and cranial nerves.

Background: Central nervous system (CNS) hemangioblastoma (HB) is one of the most common manifestations in von Hippel-Lindau disease (VHL), but large-scale studies on clinical features of CNS HB in VHL are scarce., Methods: On the basis of the results of a questionnaire, we collected data of VHL patients with CNS HB., Results: The total number of CNS HBs in 111 VHL patients (male 59, female 52) was 264 with the following distributions: cerebellar, 65.4 %; brainstem, 9.9 %; spinal cord, 23.9 %; and pituitary, 1. 1 %. The follow-up period was 0.6 to 39.2 years, with the mean 12.5 years. Patients bearing brainstem or spinal cord HB also had another HB significantly more frequently than those bearing cerebellar HBs (P < 0.05). The mean onset age of CNS HB was 29.1 years, and that of patients bearing a single HB (mean 34.4 years) was significantly greater than that of multiple HBs (mean 25.7 years). Patients with multiple HBs under 40 years are more dominant than those with a single HB. The distribution rate of brainstem HB is significantly smaller in patients below 30 years than patients above 29 years. Although ECOG PS score increased along with number of operations, the onset age decreased with increasing number of operations. The mean ECOG PS score of patients below 20 years is significantly smaller than patients above 19 years., Conclusions: When the onset age of CNS HB is under 40 years, and CNS HB is located at the brainstem or spinal cord HB, the probability of multiple occurrence can be predicted. Since patients with an onset age under 20 years old preserve a high performance status, early detection of CNS HB would be important. In addition, since a multiple operations aggravate performance status, number of operations should be reduced.

Background: To obtain information on affected vessels in moyamoya disease (MMD), we analyzed the vascular morphological characteristics of MMD using three-dimensional (3D) constructive interference in steady-state (CISS) magnetic resonance imaging (MRI)., Methods: The population of this 3D-CISS MRI study consisted of 51 patients with MMD: 16 patients with atherosclerotic middle cerebral artery (MCA) stenosis or occlusion, 42 MRI control patients, and 28 control digital subtraction angiography (DSA) patients. We measured the outer diameters of the terminal portion of the internal carotid artery (ICA) and the proximal portion of the MCA (M1 portion). We evaluated the inner diameter as the relative value (%) obtained from magnified DSA images and analyzed these data., Results: The outer diameters of the ICA and M1 portions were significantly smaller in the MMD group than in the other two groups, while the M1 outer diameter of the atherosclerosis group was not significantly different compared to the control (ICA: MMD, 2.61 ± 0.46 mm vs. control, 4.04 ± 0.50 mm and M1: MMD, 1.92 ± 0.43 mm vs. control, 3.34 ± 0.54 mm vs. atherosclerosis, 3.45 ± 0.56 mm). Furthermore, in MMD patients, the outer diameter was unrelated to the progression of the luminal stenosis grade estimated by DSA., Conclusions: This is the first report that the outer diameters of both the ICA and M1 decrease in MMD patients. Our findings suggest that the vascular constrictive changes of the affected arteries are an important phenomenon reflecting MMD pathology.

Background: A substantial number of patients with brain tumors develop recurrent seizures, known as tumor-associated epilepsy. It is important to identify specific subgroups of brain tumor patients with higher incidences of epilepsy because a meta-analysis failed to certify the effectiveness of prophylactic anti-epileptic drugs (AEDs) to abort tumor-associated epilepsy as a whole., Methods: To investigate the relationship between tumor location and incidence of epilepsy, we performed voxel-wise comparison between 3D MRI scans obtained from patients with meningioma-associated epilepsy and those from control patients using spatial normalization techniques on neuroimaging data. Variables such as age, tumor size, the degree of edema, and pathological diagnosis were also compared between the two groups., Results: Our results showed the highest incidence of epilepsy when the tumor was located on the premotor cortex in the frontal lobe (Z-scores >2.0, Liebermeister's quasi-exact test). The stepwise multiple regression analysis on the clinical data revealed that the tumor diameter (p < 0.001) and the patient's age (p = 0.024) were positive and negative predictors, respectively, for the onset of epilepsy., Conclusions: The incidence of epilepsy was higher in meningiomas located on the premotor cortex than on the other cortex. Larger volume also contributed to the onset of epilepsy. We suggest that variations of epilepsy incidence dependent on tumor characteristics can be considered when treating tumor-associated epilepsy.

A 51-year-old hypertensive man presented with subarachnoid haemorrhage. He had a past history of cerebellar infarction due to occlusion of the right posterior inferior cerebellar artery (PICA) 4 years earlier. Digital subtraction angiography showed a saccular aneurysm above an arterial loop extending from the vertebral artery to the distal part of the PICA, reminiscent of peripheral PICA branches. We performed aneurysmal neck clipping with excellent outcome. Aneurysms at anastomotic arteries are extremely rare and can result from increased haemodynamic stress. We report the first case of a ruptured aneurysm at an anastomotic artery in the posterior circulation territory.

Background: ¹²³I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy is a useful tool for differentiating idiopathic Parkinson's disease (PD) from other parkinsonian syndromes, but its prognostic value in PD has not been established. The objective of this study was to clarify the correlation between cardiac MIBG uptake parameters and the outcome in PD patients subjected to the subthalamic nucleus stimulation., Method: We enrolled 31 consecutive PD patients and calculated the heart-to-mediastinum ratio (H/M) and washout rate (WR) based on the activity measured at 15 min (early phase) and 3 h (delayed phase) after the intravenous injection of MIBG (111 MBq). Cardinal motor symptoms and activity of daily living (ADL) were assessed on the Unified Parkinson's Disease Rating Scale (UPDRS) and Schwab and England (S-E) ADL scale, before and 3 months after surgery., Findings: Neither early nor delayed H/M correlated with any of the preoperative subscores on the UPDRS or S-E, nor with postoperative outcome. On the other hand, increased WR was a positive predictor for postoperative improvement rate on S-E in medication-off state (p = 0.00003). Also, WR showed a more faint but significant correlation with preoperative levodopa responsiveness on S-E (p = 0.008)., Conclusion: Our findings suggest that ¹²³I-MIBG scintigraphy in combination with levodopa-responsiveness evaluation may represent a useful tool for prediction of outcomes in patients subjected to STN stimulation.

Background: Since optimal patient selection is essential for the success of subthalamic nucleus (STN) stimulation, the identification of reliable outcome predictors is important. The purpose of this study was to identify new imaging characteristics sufficiently reliable to predict treatment results., Method: Using preoperative magnetic resonance imaging studies of 21 Parkinson disease (PD) patients treated by STN stimulation, we performed whole brain-based analysis of voxel-based morphometry (VBM) data. Intracranial structures segmented into the gray matter fraction (GMF), white matter fraction (WMF), and cerebrospinal fluid fraction (CSFF) were subjected to univariate and multivariate analysis of the correlation between fractional volumes and postoperative improvement rates using the Unified PD Rating Scale (UPDRS)., Findings: At 3 months after surgery, the WMF was significantly correlated with improvement rated on the total UPDRS (p = 0.006), UPDRS part II (activities of daily living; p = 0.008), UPDRS part III (motor; p = 0.005). In contrast, there was no significant correlation between the effect of STN stimulation and GMF or the effect of stimulation and CSFF. The WMF also showed a significant correlation with postoperative scores in the "on" drug and "on" stimulation state (total UPDRS, p = 0.027; UPDRS part II, p = 0.019; UPDRS part III, p = 0.034)., Conclusions: Our data indicate that patients with a larger white matter volume benefited from STN stimulation whereas the volume of other brain structures was not correlated with its effect. We posit that preserved connectivity between components of the basal ganglia-thalamocortical circuit may be required for the effectiveness of electrical stimulation. VBM may represent a powerful tool to predict the response of patients with advanced PD to STN stimulation.

The authors report a rare example of an isolated dissecting posterior inferior cerebellar artery (PICA) aneurysm with spontaneous resolution. A 41 year-old male suffered sudden dizziness, nausea and vomiting. An angiogram and magnetic resonance imaging (MRI) detected an isolated PICA dissection. The patient was treated conservatively and recovered without any apparent neurological deficit. MRI detected the self-resolution of the dissecting aneurysm. Dissecting PICA aneurysms, especially non-haemorrhagic lesions, have the possibility of spontaneous resolution resulting in a favorable outcome. The treatment strategy for this vascular lesion may be decided based upon neuroradiological changes on careful follow-up.

Background: Haemorrhage from meningiomas is rare and the underlying pathophysiological mechanisms remain to be determined. We sought to identify these mechanisms by studying clinical and histological records of 6 meningioma patients treated at our institution., Patients and Methods: We retrospectively studied 6 patients with meningiomas whose acute onset was due to haemorrhage. We evaluated clinical features and imaging studies. The vascularity and proliferative nature of these tumours were examined immunohistochemically and tissue factor (TF) immunoreactivity was assessed. For comparison we evaluated 25 non-haemorrhagic meningiomas., Findings: At onset, the haemorrhages mimicked stroke in all 6 patients. On imaging studies, 3 of the haemorrhages were intra- and extratumoural, the other 3 were extratumoural only. Hyperintensity on T2-weighted MRI was a characteristic of these meningiomas. Histologically, they were of 3 subtypes, meningothelial (n=3), transitional (n=2), and anaplastic (n=1). The MIB-1 labelling index of the 5 WHO Grade I meningiomas was 5.8+/-2.2. The mean number of CD31-positive blood vessels did not differ in haemorrhagic and non-haemorrhagic meningiomas. The TF-positivity rate of haemorrhagic meningiomas was higher than of non-haemorrhagic meningiomas., Interpretation: The proliferative nature of the meningiomas and TF expression in tumour cells may have contributed to the eventual haemorrhage of the meningiomas in our series.

Background: Since metastatic brain tumours from esophageal carcinoma are essentially rare, previous reports have not determined the common neuro-radiological findings and its clinical aspects., Findings: We report the neuro-imaging and clinicopathological features of our 8 metastatic brain tumours from an esophageal site. Histologically, 6 of our 8 patients had squamous cell carcinoma and 2 had small cell carcinoma, a rare variant form. Both histological types mainly exhibited cystic lesions with a thin enhanced rim on magnetic resonance images (MRI, 4 of 6 squamous cell carcinomas and 1 of 2 small cell carcinomas). Combination therapy (irradiation and chemotherapy) after surgical treatment, the number of metastatic brain tumours, and the interval between their appearance and the diagnosis of the primary lesion could be prognostic factors in our series., Interpretation: Among Japanese, the vast majority of primary esophageal cancers are squamous cell carcinomas. Therefore, MRI findings of a cystic tumour with a thin enhanced rim may alert one to the possibility of a metastatic brain tumour from the esophagus.

Intracranial intraparenchymal schwannomas are rare. We report three patients with an intracranial intraparenchymal schwannoma and discuss the clinical and neuroradiological aspects of this particular tumour. The patients were a 21-year-old male, a 64-year-old female and a 17-year-old male. The tumours were located in cerebrum in two patients and the cerebellum in one patient. Computerized tomography (CT) scans demonstrated a slightly high density area with homogeneous enhancement by contrast medium. Magnetic resonance imaging (MRI) showed slightly low signal intensity on the T1-weighted image, high or mixed signal intensity on the T2-weighted image and homogeneous enhancement by gadolinium diethylene triamine penta-acetic acid (Gd-DTPA). Radiological studies revealed cystic components in 2 of the 3 patients. All tumours were firm, well-demarcated, and completely removed. The diagnosis of schwannoma was derived from histological and immunohistochemical studies in all 3 cases; 2 cases were also examined by electron microscopy.

The distribution of 125I-labelled recombinant mouse interferon-beta (rMuIFN-beta) in normal and glioma (203 glioma) bearing mice was studied by radioassay and macro-autoradiography at 15 and 30 min after a single intravenous injection. The level of rMuIFN-beta in the spleen was about 20-fold higher than in serum. Concentrations higher than the serum level was detected in the lung, liver and kidney. The concentration of rMuIFN-beta in the brain was 8% of the serum level and the concentration in the glioma 30 min after administration was about 10-fold higher than in normal mouse brain. Macro-autoradiographic study demonstrated a wide distribution range and selective uptake in glioma tissue. Furthermore, we found that mouse gliomas were sensitive to mouse IFN-beta. Our findings demonstrate that in the mouse glioma model, intravenously administered interferon reaches the tumour.

We described two histochemical patterns of IgG deposits in meningioma and discussed the pathogenesis of IgG deposits. In meningioma with pseudopsammoma bodies, IgG was secreted from tumour cells which differentiated to secretory epithelial cells, and was found to deposit in the pseudopsammoma bodies. However, in meningioma without pseudopsammoma bodies, IgG was derived from plasma and became deposit around the blood vessels in the meningioma tissue.

A case of meningioma arising from the right sphenoidal ridge is presented. Histologically, the tumour was composed of whorls of meningotheliomatous cells and many tumour cells containing intracellular inclusions were PAS positive, but diastase and neuraminidase resistant. The inclusions were named pseudopsammoma bodies by Kepes in 1961. The meningioma with pseudopsammoma bodies are a very rare entity and have been described in only 7 previous reports. We had an opportunity to examine one case of a meningioma with pseudopsammoma bodies. Electron microscopically, these substances were located in the intracellular spaces lined by microvilli. In earlier reports, the substances were said to be secretory products and a possibility of meningioma cell differentiation to secretory cell was postulated. Using the Concanavalin A staining method, the results of our present study strongly support this opinion.