Search

Two cases of high-grade glioma comprising sheets of oligodendroglial cells multifocally disrupted by regions of remarkable neuronal differentiation are described. These tumours morphologically resemble 'oligodendroglioma with ganglioglioma-like maturation', a rare tumour of man, but appear to be phenotypically more aggressive. Neuronal markers (synaptophysin, neuron-specific enolase and βIII-tubulin) effectively highlight neuronal elements within these tumours and could potentially help to further investigate the prevalence and biological significance of neuronal differentiation in canine oligodendroglioma., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background and Purpose: Atherosclerotic plaque composition and structure contribute to the risk of plaque rupture and embolization. Virtual histology by intravascular ultrasonography and high-resolution MR imaging are new imaging modalities that have been used to characterize plaque morphology and composition in peripheral arteries., Materials and Methods: The objectives of this study were 1) to determine the correlation between virtual histology-intravascular ultrasonography and histopathologic analysis (reference standard) and 2) to explore the comparative results of 7T MR imaging (versus histopathologic analysis), both to be performed in vitro by use of intracranial arterial segments with atherosclerotic plaques. Thirty sets of postmortem samples of intracranial circulation were prepared for the study. These samples included the middle cerebral artery (n = 20), basilar artery (n = 8), and anterior cerebral artery (n = 2). Virtual histology-intravascular ultrasonography and 7T MR imaging were performed in 34 and 10 points of interest, respectively. The formalin-fixed arteries underwent tissue processing and hematoxylin-eosin staining. The plaques were independently categorized according to revised Stary classification after review of plaque morphology and characteristics obtained from 3 modalities. The proportion of fibrous, fibrofatty, attenuated calcium, and necrotic components in the plaques were determined in histology slides and compared with virtual histology-intravascular ultrasonography and MR imaging., Results: Of 34 points of interest in the vessels, 32 had atherosclerotic plaques under direct visualization. Plaques were visualized in gray-scale intravascular ultrasonography as increased wall thickness, outer wall irregularity, and protrusion. The positive predictive value of virtual histology-intravascular ultrasonography for identifying fibroatheroma was 80%. Overall, virtual histology-intravascular ultrasonography accurately diagnosed the type of the plaque in 25 of 34 samples, and κ agreement was 0.58 (moderate agreement). The sensitivity and specificity of virtual histology-intravascular ultrasonography readings for fibroatheroma were 78.9% and 73.3%, respectively. The overall sensitivity and specificity for virtual histology-intravascular ultrasonography were 73.5% and 96.6%, respectively. Plaques were identified in 7T MR imaging as increased wall thickness, luminal stenosis, or outer wall protrusion. The positive predictive value of 7T MR imaging for detecting fibrous and attenuated calcium deposits was 88% and 93%, respectively., Conclusions: This in vitro study demonstrated that virtual histology-intravascular ultrasonography and high-resolution MR imaging are reliable imaging tools to detect atherosclerotic plaques within the intracranial arterial wall, though both imaging modalities have some limitations in accurate characterization of the plaque components. Further clinical studies are needed to determine the clinical utility of plaque morphology and composition assessment by noninvasive tests.

Lymphomatoid granulomatosis (LA) is a rare angiocentric lymphoreticular proliferative disease that primarily involves the lungs but may also involve extrapulmonary sites including the central nervous system, skin, and kidneys. It is rare for this condition to affect children, and presentation as a cerebellar mass is unusual. In this report, we describe a 10-year-old girl with biopsy-proved cerebellar LA.

Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disease caused by the expression of mutant ataxin-1 that contains an expanded polyglutamine tract. Overexpression of mutant ataxin-1 in Purkinje cells of transgenic mice results in a progressive ataxia and Purkinje cell pathology that are very similar to those seen in SCA1 patients. Two prominent aspects of pathology in the SCA1 mice are the presence of cytoplasmic vacuoles and dendritic atrophy. We found that the vacuoles in Purkinje cells seem to originate as large invaginations of the outer cell membrane. The cytoplasmic vacuoles contained proteins from the somatodendritic membrane, including mGluR1, GluRDelta1/Delta2, GluR2/3, and protein kinase C (PKC) gamma. Further examination of PKCgamma revealed that its sequestration into cytoplasmic vacuoles was accompanied by concurrent loss of PKCgamma localization at the Purkinje cell dendritic membrane and decreased detection of PKCgamma by Western blot analysis. In addition, the vacuoles were immunoreactive for components of the ubiquitin/proteasome degradative pathway. These findings present a link between vacuole formation and loss of dendrites in Purkinje cells of SCA1 mice and indicate that altered somatodendritic membrane trafficking and loss of proteins including PKCgamma, are a part of the neuronal dysfunction in SCA1 transgenic mice.

Objective and Importance: Venous obstruction has been postulated as a cause of increased intracranial pressure, but it has been documented rarely. We present a case of obstruction of the torcula by a slow-growing epidermoid. The tumor caused increased intracranial pressure, which was relieved when it was excised. In addition, the torcular epidermoid is associated with a bifid straight sinus., Clinical Presentation: A 35-year-old man presented with a headache and a lump on the back of the head. Physical examination revealed a firm, bony lesion approximately 4 x 4 cm in size. Lumbar puncture demonstrated an intraspinal pressure of 39 cm H2O. Neuroradiological studies revealed an epidermoid that compressed and almost completely occluded the torcula., Intervention: After the tumor was resected, the intraspinal pressure decreased to 19 cm H2O and remained stable 6 months later., Conclusion: Pure venous obstruction causes increased intracranial pressure. Removal of the obstruction relieves the intracranial hypertension. In addition, computed tomographic venography is a safe and easy method of documenting torcular anatomy, and it was useful in the follow-up of this patient. Computed tomographic venography can demonstrate a double straight sinus, which is a congenital variant that may be associated with the epidermoid.

We evaluate the impact of extent of surgery (EOS) on survival of patients with supratentorial nonpilocytic low-grade gliomas (LGG) treated with postoperative radiation therapy (PORT). Sixty-five patients with pathologically confirmed supratentorial nonpilocytic LGG (36 astrocytomas and 29 oligodendrogliomas) were treated with PORT after different extents of surgery: 12 gross total resections (GTR), 27 minimal or subtotal resections (MR/SR), and 26 biopsies (B). EOS was confirmed with postoperative imaging. The median radiation dose delivered was 5,940 cGy (range, 4,950-6,620 cGy). One of 12 patients (8%) in the GTR group and 12 of 53 patients (23%) in the less than GTR group demonstrated contrast enhancement. The median follow-up was 61 months (range 5-194 month). The 10-year overall survival (OS) was 82.5% and 32% for the GTR and the less than GTR groups, respectively (P = 0.0008). The corresponding 10-year disease-specific survival (DSS) was 90% and 41.4%%, respectively (P = 0.001). Multivariate analysis showed that only contrast enhancement and EOS were predictors for OS and DSS. Our data suggest that EOS correlates with OS and DSS in patients who have PORT. GTR should be the goal if technically achievable without causing significant morbidity, and its combination with PORT is compatible with long-term survival., (Copyright 2002 Wiley-Liss, Inc.)

Spinocerebellar ataxia type 1 (SCA1) is one of a group of dominantly inherited neurodegenerative diseases caused by a mutant expansion of a polyglutamine-repeated sequence within the affected gene. One of the major cell types affected by the gene (ataxin-1) mutation in SCA1 is the cerebellar Purkinje cell. Targeted expression of mutant ataxin-1 in Purkinje cells of transgenic mice produces an ataxic phenotype with pathological similarities to the human disease. Other transgenic experiments using altered forms of mutant ataxin-1 have shown that nuclear localization of the mutant protein is necessary for pathogenesis and that nuclear aggregates of ubiquitinated mutant protein, while a feature of SCA1 and other polyglutamine diseases, are not a requirement for pathogenesis in transgenic models of SCA1. Present and future generations of transgenic mouse models of SCA1 will be valuable tools to further address mechanisms of pathogenesis in polyglutamine-related disorders.

Purpose: To evaluate the efficacy of stereotactic radiotherapy (SRT) in patients with recurrent high-grade gliomas by comparing two different treatment regimens, single dose or fractionated radiotherapy., Methods and Materials: Between April 1991 and January 1998, 71 patients with recurrent high-grade gliomas were treated with SRT. Forty-six patients (65%) were treated with single dose radiosurgery (SRS) and 25 patients (35 %) with fractionated stereotactic radiotherapy (FSRT). For the SRS group, the median radiosurgical dose of 17 Gy was delivered to the median of 50% isodose surface (IDS) encompassing the target. For the FSRT group, the median dose of 37.5 Gy in 15 fractions was delivered to the median of 85% IDS., Results: Actuarial median survival time was 11 months for the SRS group and 12 months for the FSRT group (p = 0.3, log-rank test). Variables predicting longer survival were younger age (p = 0.006), lower grade (p = 0.0006), higher Karnofsky Performance Scale (KPS) (p = 0.0005), and smaller tumor volume (p = 0.02). Patients in the SRS group had more favorable prognostic factors, with median age of 48 years, KPS of 70, and tumor volume of 10 ml versus median age of 53 years, KPS of 60, and tumor volume of 25 ml in the FSRT group. Late complications developed in 14 patients in the SRS group and 2 patients in the FSRT group (p<0.05)., Conclusion: Given that FSRT patients had comparable survival to SRS patients, despite having poorer pretreatment prognostic factors and a lower risk of late complications, FSRT may be a better option for patients with larger tumors or tumors in eloquent structures. Since this is a nonrandomized study, further investigation is needed to confirm this and to determine an optimal dose/fractionation scheme.

The prostaglandin synthesizing enzyme cyclooxygenase-2 (COX-2) is up-regulated in the brain of rodents during cerebral ischemia and contributes to ischemic brain injury. This study sought to determine whether COX-2 is also up-regulated in the human brain in the acute stages of cerebral ischemic infarction. Paraffin-embedded sections from patients who died 1-2 days following infarction in the middle cerebral artery territory were processed for COX-2 immunohistochemistry. COX-2 immunoreactivity was observed in infiltrating neutrophils, in vascular cells and in neurons located at the border of the infarct. The data suggest that COX-2 up-regulation is also relevant to cerebral ischemia in humans and raise the possibility that COX-2 reaction products participate in the mechanisms of ischemic injury also in the human brain.

The inducible or "immunological" isoform of nitric oxide synthase (iNOS) is induced in many cell types by inflammatory stimuli and synthesizes toxic amounts of NO. In rodent models of focal cerebral ischemia, iNOS is expressed in neutrophils invading the injured brain and in local blood vessels. Studies with iNOS inhibitors and iNOS null mice indicate that NO produced by iNOS contributes to ischemic brain injury. In the present study, we sought to determine whether iNOS is also expressed in the human brain after ischemic stroke. Studies were conducted using immunohistochemistry on autopsy brains with neuropathological evidence of acute cerebral infarction. iNOS immunoreactivity was observed in neutrophils infiltrating the ischemic brain and in blood vessels within the ischemic territory. iNOS-positive cells also were immunoreactive for nitrotyrosine, reflecting protein nitration by NO-derived peroxynitrite and nitrites. iNOS or nitrotyrosine immunoreactivity was not detected outside the region of the infarct. These observations provide evidence that iNOS is expressed in the human brain after ischemic infarction and support the hypothesis that iNOS inhibitors may be useful in the treatment of ischemic stroke in humans.