Partial resection of presurgical fMRI activation is associated with a postsurgical loss of language function after frontal lobe epilepsy surgery

We describe five patients with frontal lobe epilepsy who underwent electrocortical stimulation (ES) for language localization and language functional magnetic resonance imaging (fMRI) prior to epilepsy surgery. Six months after surgery, three patients suffered from a drop of verbal fluency. In all of them, frontal areas with presurgical language fMRI activity were resected. Our results suggest that resection in regions of areas with presurgical fMRI activation is not without risk for a postsurgical loss of function, even when ES results were negative for language function in these areas. Using fMRI activations might be specifically helpful to plan the resection when ES delivered inconclusive results.

Psychiatric lifetime diagnoses are associated with a reduced chance of seizure freedom after temporal lobe surgery

OBJECTIVE

To examine whether psychiatric comorbidity is a predictor of long-term seizure outcome following temporal lobe epilepsy surgery.

METHODS

A sample of 434 adult patients who received temporal lobe resection to treat epilepsy between 1991 and 2009 and were psychiatrically assessed before surgery were followed for 2 years to assess seizure outcome. Stepwise multivariate logistic regression analyses were used to assess the impact of psychiatric variables on complete seizure freedom (Engel class IA), and freedom from disabling seizures (Engel class I). Lifetime histories of three psychiatric syndromes (PS: psychosis; depression; other) and five personality disorders (PD: DSM-IV Clusters A, B, and C; organic personality disorder; other) were considered as predictors, complemented by age at onset, duration of epilepsy, type of lesion (mesiotemporal sclerosis vs. other), and year of surgery.

RESULTS

Seizure-freedom rates were significantly higher (p < 0.001) in patients with no history of PS or PD (N = 138; Engel class IA: 61.6%; Engel class I: 87.7%) than in those with any PS or PD (N = 296; Engel class IA: 39.5%; Engel class I: 58.8%). Particularly low seizure-freedom rates were found in patients with a diagnosis of psychosis (N = 32, Engel class IA: 21.9%; Engel class I: 40.6%), organic PD (N = 48, Engel class IA: 25.0%; Engel class I: 35.4%) or a double diagnosis of PS plus PD (N = 97; Engel class IA: 27.8%; Engel class I: 45.5%). No other variables emerged as significant risk factors in multivariate logistic regression analyses.

SIGNIFICANCE

Patients with and without psychiatric comorbidities can benefit from temporal lobe epilepsy surgery; however, psychiatric comorbidities are negatively associated with postoperative seizure-freedom rates. Surgical outcome is related to the type and extent of preoperative psychiatric morbidity, which underscores the prognostic value of presurgical psychiatric evaluation. The data support the argument that there are common pathogenetic mechanisms underlying both epilepsy and psychiatric conditions.

Thermal requirements for growth, survival and aerobic performance of weatherfish larvae Misgurnus fossilis

Thermal requirements of larval weatherfish Misgurnus fossilis were investigated in terms of growth, survival and aerobic performance. Growth and survival of M. fossilis larvae acclimated to five temperatures (11, 15, 19, 23 and 27° C) were measured over 25 days. In the upper temperature treatments (19, 23 and 27° C), survival of larvae was stable throughout the entire rearing period (>75%), whereas 11 and 15° C resulted in severe declines in survival (to <10%). Growth of larvae (expressed as dry mass and total length) was highest at 19 and 23° C, but significantly decreased at 27° C. Routine metabolic rate of 3 days post-hatch larvae was estimated as oxygen consumption rate (ṀO₂ ) during acute exposure (30 min to 1 h) to seven temperatures (11, 15, 19, 23, 27, 31 and 35° C). Larval oxygen uptake increased with each consecutive temperature step from 11 to 27° C, until a plateau was reached at temperatures >27° C. All larvae of the 35° C regime, however, died within the ṀO₂ measurement period. M. fossilis larvae show greater than expected tolerance of high temperatures. On the other hand, low temperatures that are within the range of likely habitat conditions are critical because they might lead to high mortality rates when larvae are exposed over periods >10 days. These findings help to improve rearing conditions and to identify suitable waters for stocking and thus support the management of re-introduction activities for endangered M. fossilis.

Trends in epilepsy surgery: stable surgical numbers despite increasing presurgical volumes

INTRODUCTION

Despite the success of epilepsy surgery, recent reports suggest a decline in surgical numbers. We tested these trends in our cohort to elucidate potential reasons.

PATIENTS AND METHODS

Presurgical, surgical and postsurgical data of all patients undergoing presurgical evaluation in between 1990 and 2013 were retrospectively analysed. Patients were grouped according to the underlying pathology.

RESULTS

A total of 3060 patients were presurgically studied, and resective surgery was performed in 66.8% (n=2044) of them: medial temporal sclerosis (MTS): n=675, 33.0%; benign tumour (BT): n=408, 20.0%; and focal cortical dysplasia (FCD): n=284, 13.9%. Of these, 1929 patients (94.4%) had a follow-up of 2 years, and 50.8% were completely seizure free (Engel IA). Seizure freedom rate slightly improved over time. Presurgical evaluations continuously increased, whereas surgical interventions did not. Numbers for MTS, BT and temporal lobe resections decreased since 2009. The number of non-lesional patients and the need for intracranial recordings increased. More evaluated patients did not undergo surgery (more than 50% in 2010-2013) because patients were not suitable (mainly due to missing hypothesis: 4.5% in 1990-1993 up to 21.1% in 2010-2013, total 13.4%) or declined from surgery (maximum 21.0% in 2010-2013, total 10.9%). One potential reason may be that increasingly detailed information on chances and risks were given over time.

CONCLUSIONS

The increasing volume of the presurgical programme largely compensates for decreasing numbers of surgically remediable syndromes and a growing rate of informed choice against epilepsy surgery. Although comprehensive diagnostic evaluation is offered to a larger group of epilepsy patients, surgical numbers remain stable.

Ratenbildung bei KV-Daten mit GKV-Versicherten auf Kreisebene – ein empirisches Schätzmodell auf der Basis des Mikrozensus

Hintergrund: Daten aus der kassenärztlichen Versorgung werden u. a. in der Gesundheitsberichterstattung und der Versorgungsforschung auf Kreisebene genutzt. Für eine korrekte Ratenbildung müsste die Zahl der GKV-Versicherten im Nenner zugrunde gelegt werden, diese steht aber in einigen Bundesländern auf Kreisebene nicht zur Verfügung. Die Raten werden daher im kassenärztlichen System mit einer Surrogatgröße (definiert über die Arztkontakte) gebildet. Dies führt zu Unschärfen, sodass kleinräumige Regionalvergleiche nur bedingt möglich sind. Ziel der vorliegenden Arbeit ist ein besseres Schätzmodell für die Zahl der GKV-Versicherten auf Kreisebene.

Methodik: Der Anteil der GKV-Versicherten in den bayerischen Kreisen wird durch ein multiples lineares Regressionsmodell geschätzt. Im Modell wird der Anteil der GKV-Versicherten in den Anpassungsschichten des Mikrozensus (einer Zusammenfassung von mehreren Kreisen) erklärt durch Einflussfaktoren auf den Versicherungsstatus, die auf Kreisebene vorliegen (verfügbares Einkommen, Beamten- und Selbständigenanteil). Die durch das Modell berechneten GKV-Versichertenzahlen werden mit der Surrogatgröße verglichen. Eine konkrete Anwendung erfolgt am Beispiel der regionalen Diabetesdiagnosen aus den Daten der Kassenärztlichen Vereinigung Bayerns.

Ergebnisse: Durch das Regressionsmodell werden für die bayerischen Kreise GKV-Versichertenanteile zwischen 74,7 und 91,6% geschätzt. Der Unterschied zu der bisher genutzten Ersatzgröße beträgt bis zu 18,6 Prozentpunkte. Dies spiegelt sich dementsprechend in den Behandlungsprävalenzen wider, hier am Beispiel des Diabetes mellitus veranschaulicht.

Schlussfolgerung: Die vorliegende Analyse zeigt, mit welchen Unsicherheiten die Ratenbildung bei Daten aus der kassenärztlichen Versorgung derzeit behaftet ist und was daraus für kleinräumige Vergleiche, etwa in der Gesundheitsberichterstattung, folgt. Die Aufbereitung valider Nennerdaten im Rahmen der Datentransparenzregelung nach SGB V ist anzustreben.

Mild Malformation of Cortical Development with Oligodendroglial Hyperplasia in Frontal Lobe Epilepsy: A New Clinico-Pathological Entity

The histopathological spectrum of human epileptogenic brain lesions is widespread including common and rare variants of cortical malformations. However, 2-26% of epilepsy surgery specimens are histopathologically classified as nonlesional. We hypothesized that these specimens include also new diagnostic entities, in particular when presurgical magnetic resonance imaging (MRI) can identify abnormal signal intensities within the anatomical region of seizure onset. In our series of 1381 en bloc resected epilepsy surgery brain specimens, 52 cases could not be histopathologically classified and were considered nonlesional (3.7%). An increase of Olig2-, and PDGFR-alpha-immunoreactive oligodendroglia was observed in white matter and deep cortical layers in 22 of these patients (42%). Increased proliferation activity as well as heterotopic neurons in white matter were additional histopathological hallmarks. All patients suffered from frontal lobe epilepsy (FLE) with a median age of epilepsy onset at 4 years and 16 years at epilepsy surgery. Presurgical MRI suggested focal cortical dysplasia (FCD) in all patients. We suggest to classify this characteristic histopathology pattern as "mild malformation of cortical development with oligodendroglial hyperplasia (MOGHE)." Further insights into pathomechanisms of MOGHE may help to bridge the diagnostic gap in children and young adults with difficult-to-treat FLE.

Waterborne toxicity and diet-related effects of fungicides in the key leaf shredder Gammarus fossarum (Crustacea: Amphipoda)

Animals involved in leaf litter breakdown (i.e., shredders) play a central role in detritus-based stream food webs, while their fitness and functioning can be impaired by anthropogenic stressors. Particularly fungicides can affect shredders via both waterborne exposure and their diet, namely due to co-ingestion of adsorbed fungicides and shifts in the leaf-associated fungal community, on which shredders' nutrition heavily relies. To understand the relevance of these effect pathways, we used a full 2×2-factorial test design: the leaf material serving as food was microbially colonized for 12 days either in a fungicide-free control or exposed to a mixture of five current-use fungicides (sum concentration of 62.5μg/L). Similarly, the amphipod shredder Gammarus fossarum was subjected to the same treatments but for 24 days. Waterborne exposure reduced leaf consumption by ∼20%, which did not fully explain the reduction in feces production (∼30%), indicating an enhanced utilization of food to compensate for detoxification mechanisms. This may also explain the reduced feces production (∼10%) of gammarids feeding on fungicide-exposed leaves. The reduction may, however, also be caused by a decreased nutritious quality of the leaves indicated by a reduced species richness (∼40%) of leaf-associated fungi. However, compensation for these effects by Gammarus was seemingly incomplete, since both waterborne exposure and the consumption of the fungicide-affected diet drastically reduced gammarid growth (∼110% and ∼40%, respectively). Our results thus indicate that fungicide mixtures have the potential for detrimental implications in aquatic ecosystem functioning by affecting shredders via both effect pathways.

Molecular switches under TGFβ signalling during progression from cardiac hypertrophy to heart failure

Cardiac hypertrophy is a mechanism to compensate for increased cardiac work load, that is, after myocardial infarction or upon pressure overload. However, in the long run cardiac hypertrophy is a prevailing risk factor for the development of heart failure. During pathological remodelling processes leading to heart failure, decompensated hypertrophy, death of cardiomyocytes by apoptosis or necroptosis and fibrosis as well as a progressive dysfunction of cardiomyocytes are apparent. Interestingly, the induction of hypertrophy, cell death or fibrosis is mediated by similar signalling pathways. Therefore, tiny changes in the signalling cascade are able to switch physiological cardiac remodelling to the development of heart failure. In the present review, we will describe examples of these molecular switches that change compensated hypertrophy to the development of heart failure and will focus on the importance of the signalling cascades of the TGFβ superfamily in this process. In this context, potential therapeutic targets for pharmacological interventions that could attenuate the progression of heart failure will be discussed.

The relative importance of diet-related and waterborne effects of copper for a leaf-shredding invertebrate

Copper (Cu) exposure can increase leaf-associated fungal biomass, an important food component for leaf-shredding macroinvertebrates. To test if this positive nutritional effect supports the physiological fitness of these animals and to assess its importance compared to waterborne toxicity, we performed a 24-day-bioassay in combination with a 2×2 factorial design using the amphipod shredder Gammarus fossarum and a field-relevant Cu concentration of 25 μg/L (n = 65). Waterborne toxicity was negligible, while gammarids fed leaves exposed to Cu during microbial colonization exhibited a near-significant impairment in growth (∼30%) and a significantly reduced lipid content (∼20%). These effects appear to be governed by dietary uptake of Cu, which accumulated in leaves as well as gammarids and likely overrode the positive nutritional effect of the increased fungal biomass. Our results suggest that for adsorptive freshwater contaminants dietary uptake should be evaluated already during the registration process to safeguard the integrity of detritus-based ecosystems.