Long-term neurocognitive function and quality of life after multimodal therapy in adult glioma patients: a prospective long-term follow-up.

PURPOSE: Multimodal therapies have significantly improved prognosis in glioma. However, in particular radiotherapy may induce long-term neurotoxicity compromising patients' neurocognition and quality of life. The present prospective multicenter study aimed to evaluate associations of multimodal treatment with neurocognition with a particular focus on hippocampal irradiation. METHODS: Seventy-one glioma patients (WHO grade 1-4) were serially evaluated with neurocognitive testing and quality of life questionnaires. Prior to (baseline) and following further treatment (median 7.1 years [range 4.6-11.0] after baseline) a standardized computerized neurocognitive test battery (NeuroCog FX) was applied to gauge psychomotor speed and inhibition, verbal short-term memory, working memory, verbal and non-verbal memory as well as verbal fluency. Mean ipsilateral hippocampal radiation dose was determined in a subgroup of 27 patients who received radiotherapy according to radiotherapy plans to evaluate its association with neurocognition. RESULTS: Between baseline and follow-up mean performance in none of the cognitive domains significantly declined in any treatment modality (radiotherapy, chemotherapy, combined radio-chemotherapy, watchful-waiting), except for selective attention in patients receiving chemotherapy alone. Apart from one subtest (inhibition), mean ipsilateral hippocampal radiation dose > 50 Gy (Dmean) as compared to < 10 Gy showed no associations with long-term cognitive functioning. However, patients with Dmean < 10 Gy showed stable or improved performance in all cognitive domains, while patients with > 50 Gy numerically deteriorated in 4/8 domains. CONCLUSIONS: Multimodal glioma therapy seems to affect neurocognition less than generally assumed. Even patients with unilateral hippocampal irradiation with > 50 Gy showed no profound cognitive decline in this series.

Mid-term treatment-related cognitive sequelae in glioma patients.

PURPOSE: Cognitive functioning represents an essential determinant of quality of life. Since significant advances in neuro-oncological treatment have led to prolonged survival it is important to reliably identify possible treatment-related neurocognitive dysfunction in brain tumor patients. Therefore, the present study specifically evaluates the effects of standard treatment modalities on neurocognitive functions in glioma patients within two years after surgery. METHODS: Eighty-six patients with World Health Organization (WHO) grade 1-4 gliomas were treated between 2004 and 2012 and prospectively followed within the German Glioma Network. They received serial neuropsychological assessment of attention, memory and executive functions using the computer-based test battery NeuroCog FX. As the primary outcome the extent of change in cognitive performance over time was compared between patients who received radiotherapy, chemotherapy or combined radio-chemotherapy and patients without any adjuvant therapy. Additionally, the effect of irradiation and chemotherapy was assessed in subgroup analyses. Furthermore, the potential impact of the extent of tumor resection and histopathological characteristics on cognitive functioning were referred to as secondary outcomes. RESULTS: After a median of 16.8 (range 5.9-31.1) months between post-surgery baseline neuropsychological assessment and follow-up assessment, all treatment groups showed numerical and often even statistically significant improvement in all cognitive domains. The extent of change in cognitive functioning showed no difference between treatment groups. Concerning figural memory only, irradiated patients showed less improvement than non-irradiated patients (p = 0.029, η2 = 0.06). Resected patients, yet not patients with biopsy, showed improvement in all cognitive domains. Compared to patients with astrocytomas, patients with oligodendrogliomas revealed a greater potential to improve in attentional and executive functions. However, the heterogeneity of the patient group and the potentially selected cohort may confound results. CONCLUSION: Within a two-year post-surgery interval, radiotherapy, chemotherapy or their combination as standard treatment did not have a detrimental effect on cognitive functions in WHO grade 1-4 glioma patients. Cognitive performance in patients with adjuvant treatment was comparable to that of patients without.

False-positive results in transcranial motor evoked potentials for outcome prognostication during surgery for supratentorial lesions.

During monitoring of motor evoked potentials (MEP) elicited by transcranial electrical stimulation (TES) for prognostication of postoperative motor deficit, significant MEP changes without postoperative deterioration of motor function represent false-positive results. We aimed to investigate this phenomenon in a large series of patients who underwent resection of supratentorial lesions. TES was applied in 264 patients during resection of motor-eloquent supratentorial lesions. MEP were recorded bilaterally from arm, leg, and/ or facial muscles. The threshold criterion was applied assessing percentage increase in threshold level, which was considered significant if being > 20% higher on affected side than on the unaffected side. Subcortical stimulation was additionally applied to estimate the distance to corticospinal tract. Motor function was evaluated at 24 h after surgery and at 3-month follow-up. Patients with false-positive results were analyzed regarding tumor location, tumor volume, and characteristics of the monitoring. MEP were recorded from 399 muscles (264 arm muscles, 75 leg muscles, and 60 facial muscles). Motor function was unchanged postoperatively in 359 muscles in 228 patients. Among these cases, the threshold level did not change significantly in 354 muscles in 224 patients, while it increased significantly in the remaining 5 muscles in 4 patients (abductor pollicis brevis in all four patients and orbicularis oris in one patient), leading to a false-positive rate of 1.1%. Tumor volume, opening the ventricle, and negative subcortical stimulation did not significantly correlate with false-positive results, while the tumor location in the parietal lobe dorsal to the postcentral gyrus correlated significantly (p = 0.012, odds ratio 11.2, 95% CI 1.8 to 69.8). False-negative results took place in 1.1% of cases in a large series of TES-MEP monitoring using the threshold criterion. Tumor location in the parietal lobe dorsal to the postcentral gyrus was the only predictor of false-positive results.

Resective epilepsy surgery in patients aged 50years and older - a retrospective study regarding seizure outcome, memory performance, and psychopathology.

PURPOSE: To assess clinical and demographic characteristics in two cohorts of elderly patients with drug-resistant focal epilepsy, undergoing resective epilepsy surgery (RES). Further, to determine seizure, neuropsychological, and mental health outcomes after RES and evaluate possible influencing factors. METHODS: Consecutive patients aged ≥50 years with temporal lobe epilepsy (TLE) who underwent curative RES in the Hamburg epilepsy surgery program (2004-2017) were identified. Data were retrospectively analyzed. Seizure outcome was classified according to ILAE and Engel outcome scales in patients with first-time surgeries and with reoperations. Previously reported predictors of the seizure outcome were evaluated using regression analyses. Changes in verbal memory were assessed for patients with complete pre- and postoperative datasets (n=30) using repeated-measures analysis of variance. For evaluation of possible predictors of psychopathologic changes after RES a regression analysis was conducted. RESULTS: Fifty-one elderly patients underwent RES of the temporal lobe, including twelve aged ≥60 years, and five with reoperations. After one year, 65% of the patients with first-time surgeries were seizure free and 91% had a favorable outcome. At last follow-up, 49% were seizure free since surgery. Three reoperated patients had an Engel I outcome. Seizure outcome was not dependent on age at surgery, duration of epilepsy, or other evaluated variables. There was no significant decline in the memory performance after surgery. Significant improvements in mental health were found. CONCLUSION: RES for drug-resistant TLE is safe, effective, and improves mental health also in patients aged ≥ 50 years. Thus, it should be evaluated as the treatment of choice also in this age group.

Decision-making in temporal lobe epilepsy surgery based on invasive stereo-electroencephalography (sEEG).

In medical refractory temporal lobe epilepsy (TLE), the epileptogenic zone can be difficult to identify and therefore difficult to treat, especially in the absence of clear MRI pathologies and specific results from presurgical evaluation. Invasive monitoring with stereo-electroencephalography (sEEG) is a tool for a better determination of the epileptogenic zone. Here, we investigate the impact of sEEG on decision-making in temporal lobe epilepsy surgery. We reviewed patients with TLE who underwent further investigation with sEEG in our epilepsy unit. We examined specifically how sEEG findings influenced our decision regarding indication for a surgical procedure and resection volume. From 2013 to 2017, we performed 152 temporal resections in epilepsy patients. Twenty-one of these patients were designated for further preoperative investigation with sEEG due to incongruent findings in presurgical evaluation. Six patients were implanted bitemporally. In five cases, the hypothesis for the epileptogenic zone and localization had to be changed due to sEEG findings and resulted in a different tailored resection than intended. In three cases, sEEG findings led to the cancelation of the originally intended temporal resection as the epileptogenic zone was not definable or bilateral. In another three cases, the prognosis for reduction of seizures postoperatively had to be reduced due to the sEEG findings. However, the resection was performed after interdisciplinary discussion and informed consent of the patient. The examination by sEEG led to a change of plan for further treatment in 13 patients (61.9%) suffering TLE in total. Invasive monitoring with sEEG electrodes had a strong impact on decision-making for further treatment in patients suffering from temporal lobe epilepsy with incongruent findings in presurgical examination designated for epilepsy surgery. This applies to resection volumes as well as to prediction of seizure outcome.

Seizures as presenting symptom in patients with glioblastoma.

OBJECTIVE: The clinical course and underlying molecular causes in patients with glioblastoma presenting with seizures are poorly understood. Here we investigated clinical features and carrier systems as well as a transaminase relevant in glutamate homeostasis in patients with glioblastoma. METHODS: We performed a retrospective analysis of our clinical glioma database for clinical data during a 2-year period. Patients with glioblastoma were divided into 2 groups: symptomatic and asymptomatic for seizures. Magnetic resonance imaging (MRI) scans and tissue samples from both groups were investigated. A Cox regression analysis was performed for survival and clinical and molecular features. RESULTS: One hundred three patients diagnosed with glioblastoma in this period were identified. Twenty-three patients were symptomatic with seizures (22.3%). All were IDH-1/2 wild-type. We found no significant difference in the tumor localization between the groups. Patients with seizures from glioblastoma had significantly smaller tumors, which caused less edema compared to nonepileptogenic tumors. A significantly increased up-regulation of glutamate carrier systems was evident in symptomatic tumors compared to asymptomatic tumors. Moreover, there seems to be an oversupply of glutamate in symptomatic tumors due to dysregulation in glutamate synthesis. SIGNIFICANCE: Glioblastoma presenting with seizures is morphologically different from asymptomatic tumors. Furthermore, we were able to show that the molecular profile of these tumors, particularly glutamate homeostasis controlling systems, is significantly different.

The role of frameless stereotactic biopsy in contemporary neuro-oncology: molecular specifications and diagnostic yield in biopsied glioma patients.

INTRODUCTION: With the 2016 World Health Organization Classification of Tumors of the Central Nervous System (2016 CNS WHO), diagnosis of glioma is based on molecular parameters in addition to histology potentially leading to additional demands on quality of tissue samples. This may challenge the role of minimally invasive biopsy procedures. This study aims to evaluate the diagnostic yield of glioma samples from frameless stereotactic biopsies with focus on molecular information and explore the neuromolecular profile of a glioma biopsy cohort. METHODS: In a case series analysis, 180 consecutive frameless stereotactic biopsies with the Brainlab® Varioguide system from January 2011 to October 2017 were reviewed and patients with suspected or verified glioma were identified. Neuropathological samples were reprocessed in accordance with 2016 CNS WHO standards. RESULTS: One hundred nineteen glioma patients were identified. Analysis of IDH status could be performed in 95.8% resulting in a cumulative mutation rate of 9.6%. A complete diagnosis according to 2016 CNS WHO including grading and molecular features was achieved in 110 cases (92.4%). Entities were revised in four cases. Most common diagnosis was IDH-wildtype glioblastoma (66.4%) followed by IDH-wildtype anaplastic astrocytoma (21.8%). CONCLUSIONS: A formally complete diagnosis according to 2016 CNS WHO was achieved in the majority of cases. The biopsy cohort showed a prognostically unfavorable distribution of diagnoses and molecular features. Frameless stereotactic biopsy seems to be confirmed as a useful diagnostic tool in contemporary neuro-oncology-however, certain potential limitations should be considered.

Relapse of a group 4 medulloblastoma after 18 years as proven by histology and DNA methylation profiling.

BACKGROUND: Recent studies on medulloblastomas (MB) suggest that a large fraction of tumors appearing as late recurrence turn out to be secondary malignancies, e.g., malignant gliomas, after thorough molecular investigation. RESULTS: Here, we report of a patient with a group 4 MB that developed a distant recurrence after more than 18 years. The recurrent tumor was confirmed by histology and genome-wide DNA methylation profiling. CONCLUSION: Our case not only illustrates the potential of very late recurrences after seemingly cured group 4 MB, but also illustrates that detailed molecular analyses are indispensable in patients with a history of a previous malignancy.

Tectal gliomas: assessment of malignant progression, clinical management, and quality of life in a supposedly benign neoplasm.

OBJECTIVE Tectal gliomas constitute a rare and inhomogeneous group of lesions with an uncertain clinical course. Because these supposedly benign tumors are frequently followed up by observation over many years, the authors undertook this analysis of their own case series in an effort to demonstrate that the clinical course is highly variable and that there is a potential for a progressive biology. METHODS Clinical data analysis of 23 cases of tectal glioma (involving 9 children and 14 adults) was performed retrospectively. Radiographic data were analyzed longitudinally and MR images were evaluated for tumor volume, contrast enhancement, and growth progression. Quality of life was assessed using the EORTC BN20 and C30 questionnaires during follow-up in a subgroup of patients. RESULTS The patients' mean age at diagnosis was 29.2 years. The main presenting symptom at diagnosis was hydrocephalus (80%). Six patients were treated by primary tumor resection (26.1%), 3 patients underwent biopsy followed by resection (13.1%), and 3 patients underwent biopsy only (13.1%). For additional treatment of hydrocephalus, 14 patients (60.9%) received shunts and/or endoscopic third ventriculostomy. Radiographic tumor progression was observed in 47.9% of the 23 cases. The mean time between diagnosis and growth progression was 51.5 months, and the mean time to contrast enhancement was 69.7 months. Histopathological analysis was obtained in 12 cases (52.2%), resulting in 5 cases of high-grade glioma (3 cases of glioblastoma multiforme [GBM], grade IV, and 2 of anaplastic astrocytoma, grade III), 5 cases of pilocytic astrocytoma, 1 diffuse astrocytoma, and 1 ganglioglioma. Malignant progression was observed in 2 cases, with 1 case progressing from a diffuse astrocytoma (grade II) to a GBM (grade IV) within a period of 13 years. Quality-of-life measurements demonstrated distinct functional deficits compared to a healthy sample as well as glioma control cohorts. CONCLUSIONS Analysis of this case series shows that a major subpopulation of tectal gliomas show progression and malignant transformation in children as well as in adolescents. These tumors therefore cannot be considered inert lesions and require histological confirmation and close follow-up. Quality-of-life questionnaires show that tectal glioma patients might benefit from special psychological support in emotional, social, and cognitive functionality.

Maternal Aneurysmal Subarachnoid Hemorrhage During Pregnancy as an Interdisciplinary Task.

Maternal aneurysmal subarachnoid hemorrhage (aSAH) during pregnancy presents a challenge regarding treatment and management. Due to the limited number of cases there are no treatment guidelines available. Thus, treatment is usually done on a case-by-case basis. Here we report on four cases of aSAH during pregnancy, describing the different management strategies and suggesting a possible treatment algorithm. Patients treated between 2003 and 2013 in our center were included in this retrospective study. Clinical data focused on time management concerning gestation week (GW), microsurgical or endovascular treatment, and outcome of the patients and the fetuses. Results were compared to the present literature on this issue. Mean age was 30.8 years, initial Hunt & Hess (H&H) grade ranged from III to V. All patients suffered from aSAH during the 3rd trimester of pregnancy. In the four cases, two emergency Caesarean sections (CS) were performed. Two aneurysms were occluded by microsurgical clipping and one was treated endovascularly. One patient died before definitive treatment of the aneurysm could be achieved, whereas fetal mortality was 0%. The mean follow-up was 83 months. aSAH during pregnancy needs individualized interdisciplinary management. Efforts must focus on the mother so that a delay in the best available treatment for the pregnant patient is avoided. Therefore treatment modality should be primarily determined by the aneurysm itself. However, timing in terms of delivery of the fetus and aneurysm treatment is a crucial point.

Neuropsychological performance and seizure control after subsequent anteromesial temporal lobe resection following selective amygdalohippocampectomy.

OBJECTIVE: Selective amygdalohippocampectomy (sAHE) is a well-established treatment for temporal lobe epilepsy, commonly with favorable neuropsychological outcome. Yet, it is still unknown if subsequent resection of the anteromesial temporal lobe (AMTLR), when necessary, deteriorates neuropsychological performance in this selected group of patients. Thus, we evaluated the clinical and neuropsychological data of patients who, due to insufficient seizure control after sAHE, received a subsequent ipsilateral AMTLR and compared these findings with patients who did not receive a second resection (control group). METHODS: Patients' characteristics and neuropsychological data were assessed and analyzed in the reoperated as well as in the control group at each step of treatment. Experienced neuropsychologists conducted the standardized examination focusing on verbal, figural and working memory, speech fluency and attention. Preoperative diagnostics included further continuous video-electroencephalography monitoring, high-resolution magnetic resonance imaging and functional transcranial Doppler sonography. RESULTS: Eighty patients having received sAHE in our center from 11/2007 to 02/2013 were included in this study. Seventeen of these patients underwent subsequent AMTLR. Thirteen of these were available for follow-up after the second surgery and twelve had a comprehensive neuropsychological testing at all three steps. Analyzing the neuropsychological data revealed no significant differences compared with controls. On the individual level, the data demonstrated that improvement in a subdomain was more frequent than decline, if the performance had already deteriorated after the first procedure. Seizure control improved significantly (p < 0.001) in all patients after subsequent AMTLR resulting in seven patients being seizure-free at follow-up. SIGNIFICANCE: Subsequent AMTLR following sAHE can be a safe procedure to improve seizure outcome in selected patients. In our series the risk for further neuropsychological deterioration after the second procedure was low. The neuropsychological performance after the sAHE can be a valuable criterion to advise patients who are eligible for a second surgery on their risk of further cognitive decline.

Molecular classification of diffuse cerebral WHO grade II/III gliomas using genome- and transcriptome-wide profiling improves stratification of prognostically distinct patient groups.

Cerebral gliomas of World Health Organization (WHO) grade II and III represent a major challenge in terms of histological classification and clinical management. Here, we asked whether large-scale genomic and transcriptomic profiling improves the definition of prognostically distinct entities. We performed microarray-based genome- and transcriptome-wide analyses of primary tumor samples from a prospective German Glioma Network cohort of 137 patients with cerebral gliomas, including 61 WHO grade II and 76 WHO grade III tumors. Integrative bioinformatic analyses were employed to define molecular subgroups, which were then related to histology, molecular biomarkers, including isocitrate dehydrogenase 1 or 2 (IDH1/2) mutation, 1p/19q co-deletion and telomerase reverse transcriptase (TERT) promoter mutations, and patient outcome. Genomic profiling identified five distinct glioma groups, including three IDH1/2 mutant and two IDH1/2 wild-type groups. Expression profiling revealed evidence for eight transcriptionally different groups (five IDH1/2 mutant, three IDH1/2 wild type), which were only partially linked to the genomic groups. Correlation of DNA-based molecular stratification with clinical outcome allowed to define three major prognostic groups with characteristic genomic aberrations. The best prognosis was found in patients with IDH1/2 mutant and 1p/19q co-deleted tumors. Patients with IDH1/2 wild-type gliomas and glioblastoma-like genomic alterations, including gain on chromosome arm 7q (+7q), loss on chromosome arm 10q (-10q), TERT promoter mutation and oncogene amplification, displayed the worst outcome. Intermediate survival was seen in patients with IDH1/2 mutant, but 1p/19q intact, mostly astrocytic gliomas, and in patients with IDH1/2 wild-type gliomas lacking the +7q/-10q genotype and TERT promoter mutation. This molecular subgrouping stratified patients into prognostically distinct groups better than histological classification. Addition of gene expression data to this genomic classifier did not further improve prognostic stratification. In summary, DNA-based molecular profiling of WHO grade II and III gliomas distinguishes biologically distinct tumor groups and provides prognostically relevant information beyond histological classification as well as IDH1/2 mutation and 1p/19q co-deletion status.

Vascular events after transsylvian selective amygdalohippocampectomy and impact on epilepsy outcome.

OBJECTIVE: Epilepsy surgery is a standard treatment option for medically intractable temporal lobe epilepsy. Selective amygdalohippocampectomy (SAH) and anterior temporal lobectomy (ATL) are two of the standard surgical procedures in these cases. We conducted a retrospective analysis of patients treated with SAH via a modified transsylvian approach in our epilepsy center between 2008 and 2011, and we analyzed the impact of adjacent procedure-related infarctions on seizure outcome in these patients. METHODS: Infarctions were detected by magnetic resonance imaging (MRI) within the first week postoperatively and by a second MRI 9 months after surgical intervention. Neuropsychological testing was performed preoperatively. Evaluation of seizure outcome and postoperative neuropsychological testing were conducted approximately 1 year after epilepsy surgery. Correlative clinical data were analyzed by retrospective chart review. RESULTS: The postoperative MRI revealed temporal infarctions in 47.9% (n = 23/48) and frontal infarctions in 10.4% (n = 5/48) of the patients. These vascular events were asymptomatic in terms of focal neurologic deficits. Of the patients, 68.5% (n = 37/54) were free of disabling seizures (Engel class I) 1 year after the procedure. Patients with temporal infarctions were significantly more often free of disabling seizures (Engel class I, p = 0.046) than patients without temporal infarctions. Neuropsychological testing indicated a deterioration in verbal memory after SAH in patients with infarctions on the language-lateralized hemisphere compared to patients without infarction (p = 0.011). All other tested neuropsychological categories showed no significant differences between patients with or without infarctions. SIGNIFICANCE: Our results indicate a surprisingly high number of procedure-related temporal infarctions after transsylvian SAH. Hence, the volume of nonfunctional "eliminated" tissue is enlarged unintentionally, which is a possible explanation for better seizure outcome in these patients. This result supports the notion that ATL is the favorable procedure for temporal lobe epilepsy compared to SAH in the nondominant hemisphere, as neuropsychological deficits are rarely to be expected.

Neuropsychological assessments in patients with aneurysmal subarachnoid hemorrhage, perimesencephalic SAH, and incidental aneurysms.

Subarachnoid hemorrhage (SAH) is known to be associated with long-term cognitive deficits. Neurosurgical manipulation on the brain itself has been reported to have influence on neuropsychological sequelae. The following is a comparative study on perimesencephalic and aneurysmal subarachnoid hemorrhage patients as well as elective aneurysm patients that was carried out to determine the isolated and combined impact of surgical manipulation and hemorrhage, respectively, on long-term neuropsychological outcome. Inclusion criteria were good neurological recovery at discharge (modified Rankin Scale 0 or 1) without focal neurological deficit. Standardized psychological testing covered attention, memory, executive functions, and mood. Thirteen aneurysmal SAH patients, 15 patients undergoing elective clipping, and 14 patients with perimesencephalic SAH were analyzed. Standardized neuropsychological testing and social/professional history questionnaires were performed 2 years (mean) after discharge. Memory impairment and slower cognitive processing were found in the aneurysmal and perimesencephalic SAH groups, while elective aneurysm patients showed signs of impaired attention. However, compared with norm data for age-matched healthy controls, all groups showed no significant test results. In contrast, signs of clinical depression were seen in 9/42 patients, 45 % of all patients complained of stress disorders and 55 % of patients were unable to work in their previous professions. Nearly normal neuropsychological test results on long-term follow-up in SAH patients were unexpected. However, a 50 % rate of unemployment accompanied with stress disorders and depression manifests insufficient social and workplace reintegration. Therefore, even more specific rehabilitation programs are required following inpatient treatment to attain full recovery.

Hypoxia and oxygenation induce a metabolic switch between pentose phosphate pathway and glycolysis in glioma stem-like cells.

Fluctuations in oxygen tension during tissue remodeling impose a major metabolic challenge in human tumors. Stem-like tumor cells in glioblastoma, the most common malignant brain tumor, possess extraordinary metabolic flexibility, enabling them to initiate growth even under non-permissive conditions. We identified a reciprocal metabolic switch between the pentose phosphate pathway (PPP) and glycolysis in glioblastoma stem-like (GS) cells. Expression of PPP enzymes is upregulated by acute oxygenation but downregulated by hypoxia, whereas glycolysis enzymes, particularly those of the preparatory phase, are regulated inversely. Glucose flux through the PPP is reduced under hypoxia in favor of flux through glycolysis. PPP enzyme expression is elevated in human glioblastomas compared to normal brain, especially in highly proliferative tumor regions, whereas expression of parallel preparatory phase glycolysis enzymes is reduced in glioblastomas, except for strong upregulation in severely hypoxic regions. Hypoxia stimulates GS cell migration but reduces proliferation, whereas oxygenation has opposite effects, linking the metabolic switch to the "go or grow" potential of the cells. Our findings extend Warburg's observation that tumor cells predominantly utilize glycolysis for energy production, by suggesting that PPP activity is elevated in rapidly proliferating tumor cells but suppressed by acute severe hypoxic stress, favoring glycolysis and migration to protect cells against hypoxic cell damage.

Predicting the Outcome of Epilepsy Surgery by Covariance Pattern Analysis of Ictal Perfusion SPECT.

Previous studies on the utility of specific perfusion patterns in ictal brain perfusion SPECT for predicting the outcome of temporal lobe epilepsy surgery used qualitative visual pattern classification, semiquantitative region-of-interest analysis, or conventional univariate voxel-based testing, which are limited by intra- and interrater variability or low sensitivity to capture functional interactions among brain regions. The present study performed covariance pattern analysis of ictal perfusion SPECT using the scaled subprofile model for unbiased identification of predictive covariance patterns. Methods: The study retrospectively included 18 responders to temporal lobe epilepsy surgery (Engel I-A at 12 mo follow-up) and 18 nonresponders (≥Engel I-B). Ictal SPECT images were analyzed with the scaled subprofile model masked to group membership for unbiased identification of the 16 covariance patterns explaining the highest proportion of variance in the whole dataset. Individual expression scores of the covariance patterns were evaluated for predicting seizure freedom after temporal lobe surgery by receiver-operating-characteristic analysis. Kaplan-Meier analysis including all available follow-up data (up to 60 mo after surgery) was also performed. Results: Among the 16 covariance patterns only 1 showed a different expression between responders and nonresponders (P = 0.03). This favorable ictal perfusion pattern resembled the typical ictal perfusion pattern in temporomesial epilepsy. The expression score of the pattern provided an area of 0.744 (95% CI, 0.577-0.911, P = 0.004) under the receiver-operating-characteristic curve. Kaplan-Meier analysis revealed a statistical trend toward longer seizure freedom in patients with positive expression score (P = 0.06). The median estimated seizure-free time was 48 mo in patients with positive expression score versus 6 mo in patients with negative expression score. Conclusion: The expression of the favorable ictal perfusion pattern identified by covariance analysis of ictal brain perfusion SPECT provides independent (from demographic and clinical variables) information for the prediction of seizure freedom after temporal lobe epilepsy surgery. The expression of this pattern is easily computed for new ictal SPECT images and, therefore, might be used to support the decision for or against temporal lobe surgery in clinical patient care.

A distinct subset of glioma cell lines with stem cell-like properties reflects the transcriptional phenotype of glioblastomas and overexpresses CXCR4 as therapeutic target.

Glioblastomas contain stem-like cells that can be maintained in vitro using specific serum-free conditions. We investigated whether glioblastoma stem-like (GS) cell lines preserve the expression phenotype of human glioblastomas more closely than conventional glioma cell lines. Expression profiling revealed that a distinct subset of GS lines, which displayed a full stem-like phenotype (GSf), mirrored the expression signature of glioblastomas more closely than either other GS lines or cell lines grown in serum. GSf lines are highly tumorigenic and invasive in vivo, express CD133, grow spherically in vitro, are multipotent and display a Proneural gene expression signature, thus recapitulating key functional and transcriptional aspects of human glioblastomas. In contrast, GS lines with a restricted stem-like phenotype exhibited expression signatures more similar to conventional cell lines than to original patient tumors, suggesting that the transcriptional resemblance between GS lines and tumors is associated with different degrees of "stemness". Among markers overexpressed in patient tumors and GSf lines, we identified CXCR4 as a potential therapeutic target. GSf lines contained a minor population of CXCR4(hi) cells, a subfraction of which coexpressed CD133 and was expandable by hypoxia, whereas conventional cell lines contained only CXCR4(lo) cells. Convection-enhanced local treatment with AMD3100, a specific CXCR4 antagonist, inhibited the highly invasive growth of GS xenografts in vivo and cell migration in vitro. We thus demonstrate the utility of GSf lines in testing therapeutic agents and validate CXCR4 as a target to block the growth of invasive tumor-initiating glioma stem cells in vivo.

Luminal short-chain fatty acids and 5-HT acutely activate myenteric neurons in the mouse proximal colon.

BACKGROUND: Gastrointestinal (GI) function is critically dependent on the control of the enteric nervous system (ENS), which is situated within the gut wall and organized into two ganglionated nerve plexuses: the submucosal and myenteric plexus. The ENS is optimally positioned and together with the intestinal epithelium, is well-equipped to monitor the luminal contents such as microbial metabolites and to coordinate appropriate responses accordingly. Despite the heightened interest in the gut microbiota and its influence on intestinal physiology and pathophysiology, how they interact with the host ENS remains unclear. METHODS: Using full-thickness proximal colon preparations from transgenic Villin-CreERT2;R26R-GCaMP3 and Wnt1-Cre;R26R-GCaMP3 mice, which express a fluorescent Ca2+ indicator in their intestinal epithelium or in their ENS, respectively, we examined the effects of key luminal microbial metabolites (SCFAs and 5-HT) on the mucosa and underlying enteric neurons. KEY RESULTS: We show that the SCFAs acetate, propionate, and butyrate, as well as 5-HT can, to varying extents, acutely elicit epithelial and neuronal Ca2+ responses. Furthermore, SCFAs exert differential effects on submucosal and myenteric neurons. Additionally, we found that submucosal ganglia are predominantly aligned along the striations of the transverse mucosal folds in the proximal colon. CONCLUSIONS & INFERENCES: Taken together, our study demonstrates that different microbial metabolites, including SCFAs and 5-HT, can acutely stimulate Ca2+ signaling in the mucosal epithelium and in enteric neurons.

Automated detection and segmentation of focal cortical dysplasias (FCDs) with artificial intelligence: Presentation of a novel convolutional neural network and its prospective clinical validation.

PURPOSE: Focal cortical dysplasias (FCDs) represent one of the most frequent causes of pharmaco-resistant focal epilepsies. Despite improved clinical imaging methods over the past years, FCD detection remains challenging, as FCDs vary in location, size, and shape and commonly blend into surrounding tissues without clear definable boundaries. We developed a novel convolutional neural network for FCD detection and segmentation and validated it prospectively on daily-routine MRIs. MATERIAL AND METHODS: The neural network was trained on 201 T1 and FLAIR 3 T MRI volume sequences of 158 patients with mainly FCDs, regardless of type, and 7 focal PMG. Non-FCD/PMG MRIs, drawn from 100 normal MRIs and 50 MRIs with non-FCD/PMG pathologies, were added to the training. We applied the algorithm prospectively on 100 consecutive MRIs of patients with focal epilepsy from daily clinical practice. The results were compared with corresponding neuroradiological reports and morphometric MRI analyses evaluated by an experienced epileptologist. RESULTS: Best training results reached a sensitivity (recall) of 70.1 % and a precision of 54.3 % for detecting FCDs. Applied on the daily-routine MRIs, 7 out of 9 FCDs were detected and segmented correctly with a sensitivity of 77.8 % and a specificity of 5.5 %. The results of conventional visual analyses were 33.3 % and 94.5 %, respectively (3/9 FCDs detected); the results of morphometric analyses with overall epileptologic evaluation were both 100 % (9/9 FCDs detected) and thus served as reference. CONCLUSION: We developed a 3D convolutional neural network with autoencoder regularization for FCD detection and segmentation. Our algorithm employs the largest FCD training dataset to date with various types of FCDs and some focal PMG. It provided a higher sensitivity in detecting FCDs than conventional visual analyses. Despite its low specificity, the number of false positively predicted lesions per MRI was lower than with morphometric analysis. We consider our algorithm already useful for FCD pre-screening in everyday clinical practice.

No Evidence to Favor 99mTc-HMPAO or 99mTc-ECD for Ictal Brain Perfusion SPECT for Identification of the Seizure Onset Zone.

PURPOSE: Ictal brain perfusion SPECT with the tracer 99mTc-HMPAO or 99mTc-ECD is widely used for identification of the epileptic seizure onset zone (SOZ) in presurgical evaluation if standard pointers are uncertain or inconsistent. For both tracers, there are theoretical arguments to favor it over the other for this task. The aim of this study was to compare the performance of ictal brain perfusion SPECT between 99mTc-HMPAO and 99mTc-ECD in a rather large patient sample. PATIENTS AND METHODS: The study retrospectively included 196 patients from clinical routine in whom ictal perfusion SPECT had been performed with stabilized 99mTc-HMPAO (n = 110) or 99mTc-ECD (n = 86). Lateralization and localization of the SOZ were obtained by the consensus of 2 independent readers based on visual inspection of the SPECT images. RESULTS: The 99mTc-HMPAO group and the 99mTc-ECD group were well matched with respect to age, sex, age at first seizure, duration of disease, seizure frequency, history of previous brain surgery, and findings of presurgical MRI. The proportion of lateralizing ictal SPECT did not differ significantly between 99mTc-HMPAO and 99mTc-ECD (65.5% vs 72.1%, P = 0.36). Sensitivity of ictal perfusion SPECT (independent of the tracer) for correct localization of the SOZ in 62 patients with temporal lobe epilepsy and at least worthwhile improvement (Engel scale ≤ III) 12 months after temporal epilepsy surgery was 63%. CONCLUSIONS: This study does not provide evidence to favor 99mTc-HMPAO or 99mTc-ECD for identification of the SOZ by ictal perfusion SPECT.