[Show abstract][Hide abstract] ABSTRACT: Diffusion tensor imaging (DTI) and tractography offer the unique possibility to visualize the developing white matter macroanatomy of the human fetal brain in vivo and in utero and are currently under investigation for their potential use in the diagnosis of developmental pathologies of the human central nervous system. However, in order to establish in utero DTI as a clinical imaging tool, an independent comparison between macroscopic imaging and microscopic histology data in the same subject is needed. The present study aimed to cross-validate normal as well as abnormal in utero tractography results of commissural and internal capsule fibers in human fetal brains using postmortem histological structure tensor (ST) analysis. In utero tractography findings from two structurally unremarkable and five abnormal fetal brains were compared to the results of postmortem ST analysis applied to digitalized whole hemisphere sections of the same subjects. An approach to perform ST-based deterministic tractography in histological sections was implemented to overcome limitations in correlating in utero tractography to postmortem histology data. ST analysis and histology-based tractography of fetal brain sections enabled the direct assessment of the anisotropic organization and main fiber orientation of fetal telencephalic layers on a micro- and macroscopic scale, and validated in utero tractography results of corpus callosum and internal capsule fiber tracts. Cross-validation of abnormal in utero tractography results could be achieved in four subjects with agenesis of the corpus callosum (ACC) and in two cases with malformations of internal capsule fibers. In addition, potential limitations of current DTI-based in utero tractography could be demonstrated in several brain regions. Combining the three-dimensional nature of DTI-based in utero tractography with the microscopic resolution provided by histological ST analysis may ultimately facilitate a more complete morphologic characterization of axon guidance disorders at prenatal stages of human brain development.
Preview · Article · Dec 2015 · Frontiers in Neuroanatomy
[Show abstract][Hide abstract] ABSTRACT: Objective:
Hippocampal Sclerosis (HS) is widely recognized as a significant underlying cause of drug-resistant temporal lobe epilepsy (TLE) in adults. In contrast, HS is a rare finding in pediatric surgical series, and a higher incidence of HS associated with cortical dysplasia (i.e. FCD type IIIa according to the new ILAE classification) than in adult series has been reported. Data about the electro-clinical characteristics of this subgroup are scarce.
We studied 15 children and adolescents with drug-resistant TLE and HS who had anterior temporal lobe resection at our center with regard to electroclinical characteristics, MRI features and histopathology. Children in whom histopathology was consistent with Focal Cortical Dysplasia (FCD) type IIIa (n = 7) were compared with those who had HS only (n = 8).
Clinical characteristics associated with this highly selective subset of patients with FCD type IIIa were: the presence of febrile seizures during infancy, a shorter duration of active epilepsy and a lower age at epilepsy surgery. In addition, there were non-significant trends towards more extended abnormalities on both EEG and neuroimaging. We were, however, not able to find group differences with respect to neuropathologic subtyping of the HS.
We present the first detailed description and comprehensive data analysis of children with FCD type IIIa. According to our results, this patient group seems to show a distinct clinical phenotype.
No preview · Article · Dec 2015 · European journal of paediatric neurology: EJPN: official journal of the European Paediatric Neurology Society
[Show abstract][Hide abstract] ABSTRACT: Several morphology- and polymerase chain reaction (PCR)-based methods for chromosome 1p 19q deletion status assessment are available. Important prerequisites for all molecular techniques concern tissue quality and selection of regions of interest. The most common methods for diagnostic 1p 19q assessment are fluorescence in situ hybridization and PCR-based microsatellite analysis. While the latter requires the use of autologous blood samples, more advanced techniques such as array comparative genomic hybridization, multiplex ligation-dependent probe amplification or real-time PCR are independent from autologous DNA samples. However, due to high technical demand and experience required their applicability as diagnostic tests remains to be shown. On the other hand, chromogenic in situ hybridization evolves as attractive alternative to FISH. Herein, the available test methods are reviewed and outlined, their advantages and drawbacks being discussed in detail.
[Show abstract][Hide abstract] ABSTRACT: An optimal fixative should ideally combine the advantages of formalin fixation and freezing, allowing for good preservation of histology and molecular components, easy handling and storage, lack of toxicity, and low costs. Most of these criteria are fulfilled by ethanol-based solutions, and due to our good experience with the commercial RCL2 fixative, reflected by our published single-center trial, we initiated a multicenter ring trial. However, during its course, RCL2 was discontinued on the market. Therefore, we created our own agent, KINFix, composed of the same main constituents as RCL2, and employed it in our laboratory with similar results. Here we present our evaluation of the three fixatives formalin, RCL2, and KINFix from the perspective of histopathology as well as nucleic acid and protein analyses in comparison to fresh frozen tissues together with the multicenter ring trial data for RCL2. We observe that RCL2 and KINFix offer comparable histomorphology and superior template for molecular analyses than formalin. Moreover, KINFix as freely available fixative might overcome some of the difficulties related to the commercial agents. Therefore, we conclude that KINFix might be an attractive complement to formalin in tissue processing and advocate its use in neuropathological practice.
No preview · Article · Nov 2015 · Clinical neuropathology
[Show abstract][Hide abstract] ABSTRACT: Two cost-efficient genome-scale methodologies to assess DNA-methylation are MethylCap-seq and Illumina's Infinium HumanMethylation450 BeadChips (HM450). Objective information regarding the best-suited methodology for a specific research question is scant. Therefore, we performed a largescale evaluation on a set of 70 brain tissue samples, i.e. 65 glioblastoma and 5 non-tumoral tissues. As MethylCap-seq coverages were limited, we focused on the inherent capacity of the methodology to detect methylated loci rather than a quantitative analysis. MethylCap-seq and HM450 data were dichotomized and performances were compared using a gold standard free Bayesian modelling procedure. While conditional specificity was adequate for both approaches, conditional sensitivity was systematically higher for HM450. In addition, genome-wide characteristics were compared, revealing that HM450 probes identified substantially fewer regions compared to MethylCap-seq. Although results indicated that the latter method can detect more potentially relevant DNAmethylation, this did not translate into the discovery of more differentially methylated loci between tumours and controls compared to HM450. Our results therefore indicate that both methodologies are complementary, with a higher sensitivity for HM450 and a far larger genome-wide coverage for MethylCap-seq, but also that a more comprehensive character does not automatically imply more significant results in biomarker studies.
Full-text · Article · Oct 2015 · Scientific Reports
[Show abstract][Hide abstract] ABSTRACT: O6-methylguanine-methyltransferase (MGMT) promoter methylation status has prognostic and, in the subpopulation of elderly patients, predictive value in newly diagnosed glioblastoma. Therefore, knowledge of the MGMT promoter methylation status is important for clinical decision-making. So far, MGMT testing has been limited by the lack of a robust test with sufficiently high analytical performance. Recently, one of several available pyrosequencing protocols has been shown to be an accurate and robust method for MGMT testing in an intra- and interlaboratory ring trial. However, some uncertainties remain with regard to methodological issues, cut-off definitions, and optimal use in the clinical setting. In this article, we highlight and discuss several of these open questions. The main unresolved issues are the definition of the most relevant CpG sites to analyze for clinical purposes and the determination of a cut-off value for dichotomization of quantitative MGMT pyrosequencing results into "MGMT methylated" and "MGMT unmethylated" patient subgroups as a basis for further treatment decisions.
No preview · Article · Sep 2015 · Clinical neuropathology
[Show abstract][Hide abstract] ABSTRACT: SUMMARY MGMT promoter methylation status is a strong and independent prognostic factor in patients with newly diagnosed glioblastoma and a clinically relevant predictive marker in the subpopulation of elderly glioblastoma patients. However, there is still lack of consensus on the optimal assay for reliable MGMT promoter methylation testing and a variety of test are being used in different laboratories. Pyrosequencing is the only method for which an adequately high analytical performance (high intra- and interlaboratory repeatability and reproducibility) has been demonstrated in a fully published ring trial. For clinical decision-making MGMT promoter methylation testing should be performed only in experienced laboratories using meticulous validation of assay accuracy. Ideally, such laboratories should undergo regular accreditation through a quality control consortium.
[Show abstract][Hide abstract] ABSTRACT: Different studies suggested an oncogenic potential of the polyomaviruses JC virus, BK virus and simian virus 40, particularly in brain tumors and neuroblastoma, which belong to the most frequent malignancies in children. However, currently available data are controversial, possibly due to the different regional prevalence of the viruses and the detection techniques used. To elucidate the presence of these polyomaviruses in the indicated tumor entities and in childhood cancer in general, we have investigated a broad spectrum of pediatric malignancies, with particular emphasis on neuroblastoma from different geographic regions. More than 500 diagnostic specimens derived from 16 different pediatric cancer entities including solid tumors, leukemias and lymphomas were screened by highly sensitive and specific real-time quantitative PCR assays targeting important viral domains such as the large T-antigen, small T-antigen and virus protein 1. To ensure adequate power of the analysis, a minimum of 30 specimens were analyzed in each tumor entity. The vast majority of tumors investigated revealed negative findings, with only anecdotal presence of JC virus large/small T-antigen in individual cases of acute myeloid leukemia (1/30) and oligodendroglioma (1/30). Moreover, within a total of 111 neuroblastoma samples from different European countries, only a single case from Spain tested positive for BKV sequences. Our observations therefore reveal no evidence for the common presence of JC virus, BK virus or simian virus 40 in tumor tissue of pediatric malignancies and, in contrast to some earlier reports, provide no suggestion for an association between persistent infection with these viruses and childhood cancer.
[Show abstract][Hide abstract] ABSTRACT: The Brain Tumor Epidemiology Consortium (BTEC) is an open scientific forum, which fosters the development of multi-center, international and inter-disciplinary collaborations. BTEC aims to develop a better understanding of the etiology, outcomes, and prevention of brain tumors (http://epi.grants.cancer.gov/btec/). The 15th annual Brain Tumor Epidemiology Consortium Meeting, hosted by the Austrian Societies of Neuropathology and Neuro-oncology, was held on September 9 - 11, 2014 in Vienna, Austria. The meeting focused on the central role of brain tumor epidemiology within multidisciplinary neuro-oncology. Knowledge of disease incidence, outcomes, as well as risk factors is fundamental to all fields involved in research and treatment of patients with brain tumors; thus, epidemiology constitutes an important link between disciplines, indeed the very hub. This was reflected by the scientific program, which included various sessions linking brain tumor epidemiology with clinical neuro-oncology, tissue-based research, and cancer registration. Renowned experts from Europe and the United States contributed their personal perspectives stimulating further group discussions. Several concrete action plans evolved for the group to move forward until next year's meeting, which will be held at the Mayo Clinic at Rochester, MN, USA.
Full-text · Article · Jan 2015 · Clinical neuropathology
[Show abstract][Hide abstract] ABSTRACT: Background:
For its numerous abilities including sedation, we have been using thalidomide (TH) as the 'last therapeutic option' in patients with advanced gliomas. We noticed that a small subgroup, i.e. patients with secondary glioblastoma (GBM, whose GBM has evolved over several months or years from a less malignant glioma), survived for prolonged periods. Therefore, we retrospectively evaluated the outcomes of patients with secondary GBM treated with TH at our centre.
Patients and methods:
Starting in the year 2000, we have studied 23 patients (13 females, 10 males, with a median age of 31.5 years) with secondary GBM who have received palliative treatment with TH 100 mg at bedtime. All patients had previously undergone radiotherapy and received at least 1 and up to 5 regimens of chemotherapy.
The median duration of TH administration was 4.0 months (range 0.8-32). The median duration of overall survival after the start of TH therapy was 18.3 months (range 0.8-57). Eleven patients with secondary GBM survived longer than 1 year. Symptomatic improvement was most prominent in the restoration of a normal sleep pattern.
The palliative effects of TH, especially the normalization of a sleep pattern, were highly valued by patients and families. The prolongation of survival of patients with secondary GBM has not been reported previously.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The importance of QOL and neurocognitive functions in patients with GBM is meanwhile beyond controversy. We followed
newly diagnosed patients with GBM treated according to actual standard therapy during their course of disease by additionally
evaluating their QOL and cognitive functions. METHODS: We included 42 consecutive patients with newly diagnosed GBM. To assess
QOL we used the EORTC QLQ C30 and BN20 questionnaire. Neurocognition was measured with the NeuroCog FX. The evaluations were
done 6 times every three months, beginning at the initiation of radiotherapy. RESULTS: 21/42 patients were able to do three
assessments within 7 months. Afterwards, condition deterioration led to drop outs. The cognitive summary scale showed moderate
impairment but remained stable. Patients with left-sided tumors showed significant lower scores in the subscale verbal fluency
than patients with right-sided tumors during 4 months. The global health score of QOL decreased 20 points after the fifth
evaluation whereas perceived fatigue symptoms were already increased one assessment before. Furthermore the patientś financial
difficulties due to the disease increased strongly 7 months after diagnosis and were mentioned more frequently in younger
patients and in patients with lower education levels. CONCLUSION: QOL and cognitive long-term assessments are feasible in
patients with GBM before symptomatic progression occurs. Our study shows maintenance of QOL and cognitive summary scales before
tumor progression and highlights subgroups according to tumor location and socioeconomic factors.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The outcome of patients with malignant high-grade glioma (HGG) has improved significantly during the last decade.
In most patients the radiation field includes parts of the hypothalamus and/or the pituitary gland, which may cause a complex
pattern of neuroendocrine dysfunction. The objective to this cross-sectional study was to evaluate the prevalence of secondary
and tertiary hypothyroidism in patients following standard therapy of HGG. METHODS: Serum concentrations of pituitary and
peripheral thyroid and sexual hormones were measured in 258 subjects (122 female, 136 male) with HGG. All patients had been
treated with standard radio-chemotherapy (radiation up to 60 Gy, followed by adjuvant chemotherapy with temozolomide) up to
ten years before testing. RESULTS: TSH was reduced in 22% and increased in 18% of all cases (n = 258). Circulating fT4 and
fT3 levels were lowered in 5% and 20%, but increased in 10% and 3%, respectively. With regards to the sexual hormones, we
observed an interesting hormonal profile in men (n = 123). Pituitary hormones LH, FSH and prolactin were increased in 64%,
62% and 47% of all men. However, circulating testosterone levels were decreased in 40% of men ≤ 50 years and 16% of men >
50 years. In contrast, LH and FSH concentrations were below the lower reference limit in 75% of women > 50 years, but only
in 6% of women ≤ 50 years. Serum progesterone and estrogen levels were lowered in 39% and 36% of women ≤ 50 years and in 43%
and 0% of women > 50 years. Of note, 78% of women ≤ 50 years and 78% of women > 50 years featured increased circulating testosterone
levels. CONCLUSIONS: Standard treatment for HGG results in multiple changes of the pituitary-endocrine axis. Expecially the
finding on increased testosterone concentrations in women is striking and warrants further investigation.
[Show abstract][Hide abstract] ABSTRACT: Background:
Immune checkpoint inhibitors targeting programmed cell death 1 (PD1) or its ligand (PD-L1) showed activity in several cancer types.
We performed immunohistochemistry for CD3, CD8, CD20, HLA-DR, phosphatase and tensin homolog (PTEN), PD-1, and PD-L1 and pyrosequencing for assessment of the O6-methylguanine-methyltransferase (MGMT) promoter methylation status in 135 glioblastoma specimens (117 initial resection, 18 first local recurrence). PD-L1 gene expression was analyzed in 446 cases from The Cancer Genome Atlas.
Diffuse/fibrillary PD-L1 expression of variable extent, with or without interspersed epithelioid tumor cells with membranous PD-L1 expression, was observed in 103 of 117 (88.0%) newly diagnosed and 13 of 18 (72.2%) recurrent glioblastoma specimens. Sparse-to-moderate density of tumor-infiltrating lymphocytes (TILs) was found in 85 of 117 (72.6%) specimens (CD3+ 78/117, 66.7%; CD8+ 52/117, 44.4%; CD20+ 27/117, 23.1%; PD1+ 34/117, 29.1%). PD1+ TIL density correlated positively with CD3+ (P < .001), CD8+ (P < .001), CD20+ TIL density (P < .001), and PTEN expression (P = .035). Enrichment of specimens with low PD-L1 gene expression levels was observed in the proneural and G-CIMP glioblastoma subtypes and in specimens with high PD-L1 gene expression in the mesenchymal subtype (P = 5.966e-10). No significant differences in PD-L1 expression or TIL density between initial and recurrent glioblastoma specimens or correlation of PD-L1 expression or TIL density with patient age or outcome were evident.
TILs and PD-L1 expression are detectable in the majority of glioblastoma samples but are not related to outcome. Because the target is present, a clinical study with specific immune checkpoint inhibitors seems to be warranted in glioblastoma.
[Show abstract][Hide abstract] ABSTRACT: Meningeal involvement in multiple myeloma is rare.•We describe a patient with bilateral abducens nerve palsy and meningeal spread of multiple myeloma.•The patient was treated successfully with intrathecal chemotherapy.
No preview · Article · Oct 2014 · Journal of the Neurological Sciences
[Show abstract][Hide abstract] ABSTRACT: Objectives:
To study the functional activity of the multidrug efflux transporter P-glycoprotein (Pgp) at the blood-brain barrier of patients with temporal lobe epilepsy using (R)-[11C]verapamil (VPM)-PET before and after temporal lobe surgery to assess whether postoperative changes in seizure frequency and antiepileptic drug load are associated with changes in Pgp function.
Seven patients with drug-resistant temporal lobe epilepsy underwent VPM-PET scans pre- and postsurgery. Patients were followed up for a median of 6 years (range 4–7) after surgery. Pgp immunoreactivity in surgically resected hippocampal specimens was determined with immunohistochemistry.
Optimal surgical outcome, defined as seizure freedom and withdrawal of antiepileptic drugs, was associated with higher temporal lobe Pgp function before surgery, higher Pgp-positive staining in surgically resected hippocampal specimens, and reduction in global Pgp function postoperatively, compared with nonoptimal surgery outcome.
The data from our pilot study suggest that Pgp overactivity in epilepsy is dynamic, and complete seizure control and elimination of antiepileptic medication is associated with reversal of overactivity, although these findings will require confirmation in a larger patient cohort.