Cognitive functioning in glioblastoma patients during radiotherapy and temozolomide treatment: initial findings

The aim of this study was to evaluate cognitive functioning in newly-diagnosed glioblastoma multiforme (GBM) patients during treatment with radiotherapy (RT) plus concomitant and adjuvant temozolomide (TMZ). Cognitive assessment took place following surgery, but prior to the start of RT (baseline), after 6 weeks of RT and concomitant TMZ (1st follow-up), and after three cycles of adjuvant TMZ (2nd follow-up). Standardized cognitive summary measures and delta scores for six cognitive domains were calculated at the individual level. Cognitive functioning of progression-free GBM patients was compared to that of matched healthy controls. Analyses were performed on a group of 13 GBM patients that were progression-free during follow-up. The results showed that the majority of patients had deficits in multiple cognitive domains at baseline. Between baseline and 1st follow-up, four patients improved in one cognitive domain, four patients deteriorated in one domain, one patient improved in one domain and deteriorated in another, and four patients remained stable in all six domains. Between 1st and 2nd follow-up, the majority of patients (11) remained stable in all six cognitive domains, whereas one patient declined in one domain, and one patient showed a deterioration in two domains. Overall, between baseline and 2nd follow-up, three patients improved in one cognitive domain, two patients deteriorated in two domains, one patient improved in one domain and deteriorated in another, and seven patients remained stable in all six cognitive domains. In conclusion, preceding treatment, the majority of GBM patients show clear-cut deficits in cognitive functioning. In the course of the first 6 months of their disease, however, progression-free GBM patients undergoing radiotherapy plus concomitant and adjuvant temozolomide treatment do not deteriorate in cognitive functioning

The Lesioned Brain: Still a Small-World?

The intra-arterial amobarbital procedure (IAP or Wada test) is used to determine language lateralization and contralateral memory functioning in patients eligible for neurosurgery because of pharmaco-resistant epilepsy. During unilateral sedation, functioning of the contralateral hemisphere is assessed by means of neuropsychological tests. We use the IAP as a reversible model for the effect of lesions on brain network topology. Three artifact-free epochs (4096 samples) were selected from each electroencephalogram record before and after amobarbital injection. Functional connectivity was assessed by means of the synchronization likelihood. The resulting functional connectivity matrices were constructed for all six epochs per patient in four frequency bands, and weighted network analysis was performed. The clustering coefficient, average path length, small-world index, and edge weight correlation were calculated. Recordings of 33 patients were available. Network topology changed significantly after amobarbital injection: clustering decreased in all frequency bands, while path length decreased in the theta and lower alpha band, indicating a shift toward a more random network topology. Likewise, the edge weight correlation decreased after injection of amobarbital in the theta and beta bands. Network characteristics after injection of amobarbital were correlated with memory score: higher theta band small-world index and increased upper alpha path length were related to better memory score. The whole-brain network topology in patients eligible for epilepsy surgery becomes more random and less optimally organized after selective sedation of one hemisphere, as has been reported in studies with brain tumor patients. Furthermore, memory functioning after injection seems related to network topology, indicating that functional performance is related to topological network properties of the brain

Long-Term Effects of Temporal Lobe Epilepsy on Local Neural Networks: A Graph Theoretical Analysis of Corticography Recordings

Purpose: Pharmaco-resistant temporal lobe epilepsy (TLE) is often treated with surgical intervention at some point. As epilepsy surgery is considered a last resort by most physicians, a long history of epileptic seizures prior to surgery is not uncommon. Little is known about the effects of ongoing TLE on neural functioning. A better understanding of these effects might influence the moment of surgical intervention. Functional connectivity (interaction between spatially distributed brain areas) and network structure (integration and segregation of information processing) are thought to be essential for optimal brain functioning. We report on the impact of TLE duration on temporal lobe functional connectivity and network characteristics. Methods: Functional connectivity of the temporal lobe at the time of surgery was assessed by means of interictal electrocorticography (ECoG) recordings of 27 TLE patients by using the phase lag index (PLI). Graphs (abstract network representations) were reconstructed from the PLI matrix and characterized by the clustering coefficient C (local clustering), the path length L (overall network interconnectedness), and the ‘‘small world index’ ’ S (network configuration). Results: Functional connectivity (average PLI), clustering coefficients, and the small world index were negatively correlated with TLE duration in the broad frequency band (0.5–48 Hz). Discussion: Temporal lobe functional connectivity is lower in patients with longer TLE history, and longer TLE duration i

Attenuated AMPA Receptor Expression Allows Glioblastoma Cell Survival in Glutamate-Rich Environment

Background: Glioblastoma multiforme (GBM) cells secrete large amounts of glutamate that can trigger AMPA-type glutamate receptors (AMPARs). This commonly results in Na+ and Ca2+-permeability and thereby in excitotoxic cell death of the surrounding neurons. Here we investigated how the GBM cells themselves survive in a glutamate-rich environment. Methods and Findings: In silico analysis of published reports shows down-regulation of all ionotropic glutamate receptors in GBM as compared to normal brain. In vitro, in all GBM samples tested, mRNA expression of AMPAR subunit GluR1, 2 and 4 was relatively low compared to adult and fetal total brain mRNA and adult cerebellum mRNA. These findings were in line with primary GBM samples, in which protein expression patterns were down-regulated as compared to the normal tissue. Furthermore, mislocalized expression of these receptors was found. Sequence analysis of GluR2 RNA in primary and established GBM cell lines showed that the GluR2 subunit was found to be partly unedited. Conclusions: Together with the lack of functional effect of AMPAR inhibition by NBQX our results suggest that down-regulation and afunctionality of AMPARs, enable GBM cells to survive in a high glutamate environment without going into excitotoxic cell death themselves. It can be speculated that specific AMPA receptor inhibitors may protect normal neurons against the high glutamate microenvironment of GBM tumor

Multicenter phase II trial of temozolomide in patients with glioblastoma multiforme at first relapse

Background: Recurrent glioblastoma multiforme (GBM) is resistant to most therapeutic endeavors, with low response rates and survival rarely exceeding six months. There are no clearly established chemotherapeutic regimens and the aim of treatment is palliation with improvement in the quality of life. Patients and methods: We report an open-label, uncontrolled, multicenter phase II trial of temozolomide in 138 patients (intent-to-treat [ITI] population) with glioblastoma multiforme at first relapse and a Karnofsky performance status (KPS) ≥ 70. One hundred twenty-eight patients were histologically confirmed with GBM or gliosarcoma (GS) by independent central review. Chemotherapy-naïve patients were treated with temozolomide 200 mg/m2/day2/day orally for the first five days of a 28-day cycle. Patients previously treated with nitrosourea- containing adjuvant chemotherapy received 150 mg/m2/day for the first five days of a 28-day cycle. In the absence of grade 3 or 4 toxicity, patients on the 150 mg/m2 dose schedule were eligible for a 200 mg/m2 dose on the next cycle. Results: The primary endpoint was six-month progression-free survival assessed with strict radiological and clinical criteria. Secondary endpoints included radiological response and Health-related Quality of Life (HQL). Progression-free survival at six months was 18% (95% confidence interval (CI): 11%-26%) for the eligible-histology population. Median progression-free survival and median overall survival were 2.1 months and 5.4 months, respectively. The six-month survival rate was 46%. The objective response rate (complete response and partial response) determined by independent central review of gadolinium-enhanced magnetic resonance imaging (MRI) scans was 8% for both the ITT and eligible-histology populations, with an additional 43%;A and 45% of patients, respectively, having stable disease (SD). Objectively assessed response and maintenance of a progression-free status were both associated with HQL benefits (characterized by improvements over baseline in HQL domains). Temozolomide had an acceptable safety profile, with only 9% of therapy cycles requiring a dose reduction due to thrombocytopenia. There was no evidence of cumulative hematologic toxicity. Conclusions: Temozolomide demonstrated modest clinical efficacy, with an acceptable safety profile and measurable improvement in quality of life in patients with recurrent GBM. The use of this drug should be explored further in an adjuvant setting and in combination with other agent

[11C]Flumazenil brain uptake is influenced by the blood-brain barrier efflux transporter P-glycoprotein

Background:

Two-year results of disease activity score (DAS)-remission-steered treatment strategies aiming at drug-free remission in early arthritis patients (the IMPROVED-study)

Background: Early suppression of disease activity in (rheumatoid) arthritis (RA) patients may result in drug-free remission and prevent damage. We assessed 2-year clinical and radiological outcomes of two disease activity score (DAS)-remission-steered treatment strategies in early arthritis patients.Methods: Patients (n = 610) with early RA or undifferentiated arthritis (UA) were treated with methotrexate (MTX) and tapered high dose of prednisone. Patients in early remission (44/53 joints DAS <1.6) after 4 months tapered and stopped medication. Patients who did not achieve early DAS-remission were randomized to either MTX plus hydroxychloroquine plus sulphasalazine plus low dose prednisone (arm 1) or to MTX + adalimumab (arm 2). At four-monthly intervals, medication was tapered and stopped if DAS was <1.6 but restarted, increased or switched if DAS was ≥1.6. Proportions of (drug-free) DAS-remission (DFR) after 2 years and Sharp-van der Heijde scores (SHS) were analyzed separately for the treatment strategies and patients with RA and UA.Results: After 2 years, 301/610 (49 %) patients were in DAS-remission and 131/610 (21 %) in DFR. In the early remission group 241/387 patients (62 %) were in DAS-remission and 111/387 (29 %) DFR. In arm 1 22/83 (27 %) and in arm 2 24/78 (31 %) were in DAS-remission, and 6/83 (7 %) and 7/78 (9 %), respectively, were in DFR. RA and UA patients achieved DAS-remission in comparable percentages (RA: 234/479 (49 %), UA: 64/122 (52 %), p = 0.25). More UA patients achieved DFR (41/122 (34 %)) compared to RA patients (89/479 (19 %), p<0.001). Mean (SD) DAS over time was 1.74 (0.58) across all patients, and median (IQR) SHS progression was 0 (0–0).Conclusions: After 2 years remission-steered treatment in early RA and UA patients, DAS-remission and DFR percentages were relatively low. Patients who achieved early remission more often achieved (drug-free) remission after 2 years than patients who needed additional treatment steps in the randomization arms, and more UA than RA patients achieved DFR. Overall, disease activity and radiologic damage progression in all patients were well suppressed.Trial registration: http://www.controlled-trials.com/ISRCTN11916566 Registered 07/11/2006 and EudraCT number 2006-06186-16 Registered 16/07/2007

The influence of low-grade glioma on resting state oscillatory brain activity: a magnetoencephalography study

Purpose In the present MEG-study, power spectral analysis of oscillatory brain activity was used to compare resting state brain activity in both low-grade glioma (LGG) patients and healthy controls. We hypothesized that LGG patients show local as well as diffuse slowing of resting state brain activity compared to healthy controls and that particularly global slowing correlates with neurocognitive dysfunction. Patient and methods Resting state MEG recordings were obtained from 17 LGG patients and 17 age-, sex-, and education-matched healthy controls. Relative spectral power was calculated in the delta, theta, upper and lower alpha, beta, and gamma frequency band. A battery of standardized neurocognitive tests measuring 6 neurocognitive domains was administered. Results LGG patients showed a slowing of the resting state brain activity when compared to healthy controls. Decrease in relative power was mainly found in the gamma frequency band in the bilateral frontocentral MEG regions, whereas an increase in relative power was found in the theta frequency band in the left parietal region. An increase of the relative power in the theta and lower alpha band correlated with impaired executive functioning, information processing, and working memory. Conclusion LGG patients are characterized by global slowing of their resting state brain activity and this slowing phenomenon correlates with the observed neurocognitive deficits

‘Functional Connectivity’ Is a Sensitive Predictor of Epilepsy Diagnosis after the First Seizure

Background: Although epilepsy affects almost 1 % of the world population, diagnosis of this debilitating disease is still difficult. The EEG is an important tool for epilepsy diagnosis and classification, but the sensitivity of interictal epileptiform discharges (IEDs) on the first EEG is only 30–50%. Here we investigate whether using ‘functional connectivity ’ can improve the diagnostic sensitivity of the first interictal EEG in the diagnosis of epilepsy. Methodology/Principal Findings: Patients were selected from a database with 390 standard EEGs of patients after a first suspected seizure. Patients who were later diagnosed with epilepsy (i.e. $two seizures) were compared to matched nonepilepsy patients (with a minimum follow-up of one year). The synchronization likelihood (SL) was used as an index of functional connectivity of the EEG, and average SL per patient was calculated in seven frequency bands. In total, 114 patients were selected. Fifty-seven patients were diagnosed with epilepsy (20 had IEDs on their EEG) and 57 matched patients had other diagnoses. Epilepsy patients had significantly higher SL in the theta band than non-epilepsy patients. Furthermore, theta band SL proved to be a significant predictor of a diagnosis of epilepsy. When only those epilepsy patients without IEDs were considered (n = 74), theta band SL could predict diagnosis with specificity of 76 % and sensitivity of 62%. Conclusion/Significance: Theta band functional connectivity may be a useful diagnostic tool in diagnosing epilepsy