Assessing the Hemodynamics in Residual Cavities of Intracranial Aneurysm after Coil Embolization with Combined Computational Flow Dynamics and Silent Magnetic Resonance Angiography.

BACKGROUND AND PURPOSE: Metal artifacts limit computational fluid dynamics analysis after coil embolization. Silent magnetic resonance angiography reduces metal artifacts and improves visualization of the residual cavity of coil-embolized aneurysms. This study investigated the flow dynamics of the residual cavity after coil embolization using silent magnetic resonance angiography and computational fluid dynamics to elucidate the hemodynamic characteristics of recanalization. METHODS: Twenty internal carotid-posterior communicating aneurysm cases treated with coil embolization and without stent assistance were followed up (mean±standard deviation, 13.0±6.1 months) and assessed using silent magnetic resonance angiography. The hemodynamic characteristics of the residual cavities in both types of aneurysms were compared between neck remnants, which persisted for >12 months (NR group), and those treated with coil compaction-induced body filling (BF group). Computational fluid dynamics analysis of each aneurysm was performed using morphological data obtained from silent magnetic resonance angiography. Pressure, pressure difference, normalized wall shear stress, and flow velocity were measured. RESULTS: The residual cavity was well-visualized using silent magnetic resonance angiography and compared with those imaged using conventional time-of-flight magnetic resonance angiography, and eight internal carotid-posterior communicating aneurysms with neck remnants and body filling were investigated. The maximum pressure area was localized to the aneurysm wall in the NR group (n=4) and to sides of the coil surface in the BF group (n=4). No significant differences were observed for each hemodynamic parameter. CONCLUSIONS: Combination of silent magnetic resonance angiography and computational fluid dynamics helps to understand the hemodynamic characteristics of residual cavity in coil- embolized aneurysms. The flow-impingement zone at the coil surface (maximum pressure area) may influence the risk for future coil compaction.

[A Case of Subdural Empyema with Cerebral Arteritis and Brain Ischemia in the Middle Cerebral Artery Distribution, Secondary to Odontogenic Maxillary Sinusitis].

We present a rare case of subdural empyema with cerebral arteritis and brain ischemia in the middle cerebral artery distribution secondary to odontogenic maxillary sinusitis. A 32-year-old man was admitted to our hospital because of high fever and generalized convulsions. Computed tomography(CT)and magnetic resonance imaging(MRI)showed subdural empyema at the left convexity, with a small amount of air. An interruption of the right maxillary sinus floor corresponding to the alveolar process was evident on coronal CT. He was diagnosed as having subdural empyema caused by odontogenic maxillary sinusitis. MR angiography showed stenosis of the left middle cerebral artery(MCA). Despite antibiotic administration, he became drowsy and developed aphasia with right hemiparesis. Repeat MRI showed enlargement of the encapsulated subdural empyema with increased midline shift to the right. We performed prompt surgical evacuation with craniotomy, endoscopic drainage of the sinusitis, and tooth extraction. A hyperintense lesion was observed on subsequent diffusion-weighted imaging in the left MCA distribution. After repeat drainage of the re-enlarged subdural empyema, he was discharged without apparent neurological deficits. This case indicates that subdural empyema from odontogenic sinusitis requires a suitable imaging study of the brain, head, and neck region, and a multidisciplinary approach involving a neurosurgeon, otolaryngologist, and oral surgeon. Prompt initiation of appropriate antibiotic therapy with surgical intervention is recommended for treatment of subdural empyema from odontogenic sinusitis.

Opposite L-configuration double stenting for rupture of an extremely wide-necked anterior communicating artery aneurysm at the acute stage: illustrative case.

BACKGROUND: Wide-necked aneurysms can be treated by double stenting in an X- or Y-configuration or by a double waffle-cone technique. However, some aneurysms remain untreatable. OBSERVATIONS: The rupture of a complex wide-necked anterior communicating artery (AcomA) aneurysm that caused acute subarachnoid hemorrhage (SAH) was treated successfully using double stents with an opposite L-configuration as an alternative to the X-stent technique. The aneurysm involved both A1-A2 junctions in the aneurysm neck with acutely oriented A2 segments of the anterior cerebral artery bilaterally. It was densely packed and completely obliterated angiographically with preserved blood flow by implanting each stent in the ipsilateral A1-A2 bilaterally. Blood flow from the left A1 to the right A2 was confirmed through the AcomA on injection of the left internal carotid artery immediately after the procedure without critical infarction in the subthalamic area. Although the AcomA was not demonstrated by injection of the left internal carotid artery on angiography at 3 months or 1 year later, no cerebral infarction was seen on magnetic resonance images at the final hospital visit. LESSONS: Opposite L-configuration double stenting was used successfully as rescue stent-assisted coiling for a rupture of a complex wide-necked AcomA aneurysm in a patient with acute SAH.

Endovascular treatment of a ruptured aneurysm arising from the proximal end of a partial vertebrobasilar duplication with a contralateral prominent persistent primitive hypoglossal artery: illustrative case.

BACKGROUND: Ruptured aneurysms associated with a partial vertebrobasilar duplication or a persistent primitive hypoglossal artery (PPHA) have been reported. Only rarely has endovascular treatment of ruptured aneurysms in association with both vascular variations been reported. OBSERVATIONS: A 66-year-old woman experienced the sudden onset of a severe headache caused by a subarachnoid hemorrhage. Cerebral angiograms demonstrated a prominent PPHA originating from the left internal carotid artery at the C2 vertebral level and a partial vertebrobasilar duplication between the hypoplastic right vertebral artery and proximal basilar artery with a small aneurysm at the proximal end of the duplication from where the anterior spinal artery originated. The left vertebral artery was aplastic. A microcatheter was introduced into the aneurysm via the PPHA under the control of high blood flow, using a balloon-assisted technique. The aneurysm was completely obliterated with a coil. Although small cerebellar and cerebral infarcts developed during the procedure, the patient was discharged without neurological symptoms. LESSONS: To avoid serious neurological complications, precise analysis of the complex vascular anatomy, including the anterior spinal artery and hemodynamics, is clinically important for endovascular therapy of cerebral aneurysms in patients with an association between a partial vertebrobasilar duplication and a PPHA.

A homogeneously enhancing mass evolving into multiple hemorrhagic and necrotic lesions in amoebic encephalitis with necrotizing vasculitis.

BACKGROUND: Granulomatous amoebic encephalitis (GAE) is a rare and mostly fatal disease. Without specific symptoms, laboratory findings, or radiologic characteristics, establishing a correct diagnosis is challenging. In many cases of GAE, multiple ring-enhancing lesions with perifocal edema are observed on magnetic resonance imaging (MRI); a solitary and homogeneously enhancing mass masquerading as a malignant lymphoma that evolved into multiple hemorrhagic and necrotic lesions has rarely been reported in GAE. CASE DESCRIPTION: An immunocompetent 68-year-old man presented with transient right hemiparesis due to epilepsy. MRI revealed a well- and homogeneously enhancing mass with perifocal edema and restricted diffusion in the left parietal subcortical region. As malignant lymphoma was suspected based on MRI findings and an elevated ß2-microglobulin level in the cerebrospinal fluid, an open biopsy was performed; the pathological diagnosis was inconclusive but suggested a granulomatous disease. Although steroid therapy was administrated, subsequently the mass lesion gradually enlarged. After a second surgery for removal of the mass lesion, multiple hemorrhagic and necrotic lesions developed at the primary site and additionally in the brainstem. The patient entered a comatose state and died 3 months after admission. Histopathological examination and polymerase chain reaction analysis of the specimen revealed posthumously GAE caused by Balamuthia mandrillaris with necrotizing vasculitis. CONCLUSION: A solitary mass lesion initially mimicked a malignant lymphoma, and subsequently evolved into multiple hemorrhagic and necrotic lesions detected on T2*-weighted and susceptibility-weighted imaging. Such serial changes noted on MRI seem characteristic and suggestive of necrotizing vasculitis of GAE.

Multiple aneurysms on the subarcuate artery arising from the anterior inferior cerebellar artery in a patient with a Borden type I transverse-sigmoid dural arteriovenous fistula manifesting as subarachnoid hemorrhage: A case report.

BACKGROUND: Peripheral anterior inferior cerebellar artery (AICA) aneurysms are rare and commonly associated with vascular malformations, such as cerebellar arteriovenous malformations (AVMs). We present a case wherein multiple AICA feeding aneurysms on the subarcuate artery as a feeding artery of a Borden type I transverse-sigmoid dural arteriovenous fistula (dAVF) manifested as subarachnoid hemorrhage. CASE DESCRIPTION: A 67-year-old woman presented with acute severe headache. Brain computed tomography (CT) demonstrated subarachnoid hemorrhage mainly in the posterior fossa. A transverse-sigmoid dAVF was detected on magnetic resonance angiography (MRA) and three-dimensional-CT angiography (3D-CTA), with no cortical venous reflex. The patient underwent conventional angiography, which showed multiple aneurysms on a small branch of the AICA, feeding a transverse-sigmoid dAVF (Borden type I). The AICA aneurysms seemed flow dependent and ruptured owing to high-flow arteriovenous shunts through the dAVF. Based on the source images of the MRA, the small artery arising from the AICA was considered the subarcuate artery, and it was confirmed on 3D-CTA after the artery was successfully embolized with Onyx without any complications. Multiple aneurysms on the subarcuate artery are extremely rare, and the artery has not been identified as a feeding artery of the transverse-sigmoid dAVF. CONCLUSION: A rare case of multiple ruptured aneurysms on the subarcuate artery was reported in a patient with a Borden type I dAVF at the transverse-sigmoid sinuses manifesting as subarachnoid hemorrhage. Onyx embolization of the parent artery occlusion was feasible and useful in treating this type of feeding artery aneurysm of the AICA with a dAVF.

Increased expression of pituitary tumor-transforming gene (PTTG)-1 is correlated with poor prognosis in glioma patients.

Pituitary tumor-transforming gene (PTTG), which is homologous to a mammalian securin, plays a pivotal role in cell transformation and is overexpressed in numerous cancer cell lines and tissues. PTTG functions in the control of mitosis, cell transformation, DNA repair and gene regulation. In the present study, we investigated whether the expression of PTTG1 is correlated with tumorigenicity and prognosis in glioma patients. Expression of PTTG1 was confirmed in three glioma cell lines at the mRNA and protein levels using RT-PCR analysis and Western blotting, respectively. Furthermore, PTTG1 protein was detected in 44 glioma tissue samples using immunohistochemical techniques, markedly increased in high-grade gliomas compared to low-grade gliomas and associated with an unfavorable patient outcome. Moreover, siRNA against the PTTG1 gene inhibited cell proliferation and invasion in glioma cell lines. These data suggest that increased expression of PTTG1 contributes to the tumorigenicity of glioma cells and may be useful as a prognostic marker for glioma patients.

Expression level of ECT2 proto-oncogene correlates with prognosis in glioma patients.

The ECT2 (epithelial cell transforming sequence 2) proto-oncogene encodes a guanine nucleotide exchange factor for Rho GTPases, and regulates cytokinesis. ECT2 plays a critical role in Rho activation during cytokinesis, and thus may play a role in the pathogenesis of glioma. In this study, we investigated relationships between ECT2 expression, tumor histology, and prognosis in glioma patients. ECT2 mRNA expression was examined using quantitative real-time PCR, while its protein expression was examined by immunohistochemistry of 54 glioma tissue samples. Expressions of ECT2 mRNA and protein were markedly increased in high-grade gliomas compared to low-grade gliomas. Patients in whom expression of ECT2 mRNA and protein in tumor tissues was the lowest survived longer than patients who had higher expression. In vitro, ECT2 siRNA inhibited glioma cell proliferation and invasion. These data suggest that increased expression of ECT2 contribute to promotion of tumor invasiveness and progression, implying that evaluation of ECT2 expression is a prognostic marker for glioma patients.

Increased expression of CCAAT/enhancer binding protein beta correlates with prognosis in glioma patients.

C/EBP beta (CCAAT/enhancer binding protein beta) is a transcriptional factor that belongs to the basic region-leucine zipper class DNA-binding proteins and plays a role in cell differentiation and inflammatory reactions. Although high tissue levels of inflammatory cytokines, such as interleukin (IL)-6, IL-8 and transforming growth factor-beta, have been observed in glioma patients, the mechanisms underlying this phenomenon remain to be elucidated. C/EBP beta induces a variety of cytokines and thus may play a role in the pathogenesis of glioma. In this study, we investigated the relationship between C/EBP beta expression, tumor histology, and prognosis in glioma. The expression of C/EBP beta mRNA was examined with quantitative real-time PCR and protein expression was examined with immunohistochemical techniques in 47 glioma tissue samples. Expression of C/EBP beta mRNA and protein was markedly increased in high grade glioma compared with low grade glioma. Patients whose expression of C/EBP beta mRNA and protein in tumor tissue was lower survived longer than those whose expressions were higher. In vitro, C/EBP beta siRNA inhibited glioma cell proliferation and invasion. Moreover, IL-8 production by glioma cells was inhibited by C/EBP beta siRNA transfection. These data suggest that increased expression of C/EBP beta may contribute to the promotion of tumor invasiveness and progression. The data imply that the comparison of C/EBP beta expression could be a prognostic marker for patients with glioma.

Basal ganglion hamartoma in a patient presenting with precocious puberty.

We report a basal ganglion hamartoma in a 10-year-old boy in whom the major clinical feature was precocious puberty. Endocrinological evaluation showed a gonadotropin reaction to luteinizing hormone-releasing hormone with no elevation of the human chorionic gonadotropin beta-subunit level in the serum or cerebrospinal fluid. Neuroimaging studies showed a small, calcified, nonenhanced mass lesion with some cystic components in the right basal ganglion. Histopathological examination of specimens removed by stereotactic needle biopsy revealed disorganized neuronal and glial elements in the calcified gray matter-like lesion. In addition, although the presence of microcalcifications was not conspicuous, similar neuroglial lesions of various sizes were scattered in the surrounding white matter. Immunostaining for Ki-67 antigen (MIB-1) showed very low proliferative potential of the glial cells in all the lesions. To our knowledge, this is the first reported occurrence of an intracranial hamartoma located in a site other than the hypothalamus and causing precocious puberty. The possible mechanisms underlying the development of precocious puberty in this patient are discussed.