Discriminating factors in access to video-EEG for epilepsy surgery in a French tertiary epilepsy center.

Equitable access to care and management is a priority for patients with epilepsy and may vary depending on each country's healthcare system. As this issue has not been specifically addressed in France, we conducted a retrospective study to identify discriminating factors in access to surgery at a French tertiary epilepsy center. Initially, we examined factors previously identified in other countries as influential in surgery access, including age at diagnosis, affected side, gender, years of education, socio-professional categories, and density of general practitioners in the residential area, in 293 consecutive French-native patients with refractory medial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS). Subsequently, we conducted a case-control study comparing patients born in France with 22 patients born abroad to specifically explore migratory status. The analysis revealed that the only three factors statistically influencing the delay between the onset of epilepsy and entry into video-EEG were early age at onset (associated with a longer delay), pensioner status (associated with a longer delay), and student status (associated with a shorter delay). Migratory status, gender, and socio-economic level (indirectly reflected by the level of education and socio-professional category) were not found to be discriminatory factors in access to video-EEG. Discrepancies between our study and foreign studies may be attributed to differences in healthcare systems and medical coverage among countries. Efforts in France to improve access to surgery should focus on enhancing communication among practitioners to promptly refer any MTLE-HS patient to an epilepsy surgery center, regardless of their age.

Revisiting emotion recognition in different types of temporal lobe epilepsy: The influence of facial expression intensity.

Temporal lobe epilepsy (TLE) can induce various difficulties in recognizing emotional facial expressions (EFE), particularly for negative valence emotions. However, these difficulties have not been systematically examined according to the localization of the epileptic focus. For this purpose, we used a forced-choice recognition task in which faces expressing fear, sadness, anger, disgust, surprise, or happiness were presented in different intensity levels from moderate to high intensity. The first objective of our study was to evaluate the impact of emotional intensity on the recognition of different categories of EFE in TLE patients compared to control participants. The second objective was to assess the effect of localizationof epileptic focus on the recognition of EFE in patients with medial temporal lobe epilepsy (MTLE) associated or not with hippocampal sclerosis (HS), or lateral temporal lobe epilepsy (LTLE). The results showed that the 272 TLE patients and the 68 control participants were not differently affected by the intensity of EFE. However, we obtained group differences within the clinical population when we took into account the localization of the temporal lobe epileptic focus. As predicted, TLE patients were impaired in recognizing fear and disgust relative to controls. Moreover, the scores of these patients varied according to the localization of the epileptic focus, but not according to the cerebral lateralization of TLE. The facial expression of fear was less well recognized by MTLE patients, with or without HS, and the expression of disgust was less well recognized by LTLE as well as MTLE without HS patients. Moreover, emotional intensity modulated differently the recognition of disgust and surprise of the three patient groups underlying the relevance of using moderate emotional intensity to distinguish the effect of epileptic focus localization. These findings should be taken into account for interpreting the emotional behaviors and deserve to befurther investigated before considering TLE surgical treatment or social cognition interventions in TLE patients.

Examination of Large Chromosomal Inversions in the Genome of Erwinia amylovora Strains Reveals Worldwide Distribution and North America-Specific Types.

Erwinia amylovora is a relatively homogeneous species with low genetic diversity at the nucleotide level. However, phenotypic differences and genomic structural variations among E. amylovora strains have been documented. In this study, we identified 10 large chromosomal inversion (LCI) types in the Spiraeoideae-infecting (SI) E. amylovora strains by combining whole genome sequencing and PCR-based molecular markers. It was found that LCIs were mainly caused by homologous recombination events among seven rRNA operons (rrns) in SI E. amylovora strains. Although ribotyping results identified inter- and intra-variations in the internal transcribed spacer (ITS1 and ITS2) regions among rrns, LCIs tend to occur between rrns transcribed in the opposite directions and with the same tRNA content (tRNA-Glu or tRNA-Ile/Ala) in ITS1. Based on the LCI types, physical/estimated replichore imbalance (PRI/ERI) was examined and calculated. Among the 117 SI strains evaluated, the LCI types of Ea1189, CFBP1430, and Ea273 were the most common, with ERI values at 1.31, 7.87, and 4.47°, respectively. These three LCI types had worldwide distribution, whereas the remaining seven LCI types were restricted to North America (or certain regions of the United States). Our results indicated ongoing chromosomal recombination events in the SI E. amylovora population and showed that LCI events are mostly symmetrical, keeping the ERI less than 15°. These findings provide initial evidence about the prevalence of certain LCI types in E. amylovora strains, how LCI occurs, and its potential evolutionary advantage and history, which might help track the movement of the pathogen.

Epileptic seizures in patients with primary central nervous system lymphoma: A systematic review.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) accounts for less than 5% of primary brain tumors. Epileptic seizures are a common manifestation of brain tumors; however, literature on the prevalence, characteristics, and oncological implications of seizures in patients with PCNSL is limited, and the management of antiepileptic drugs (AEDs) is unclear. This review aimed to summarize the existing knowledge on seizures in PCNSL, their potential association with surgery, oncological treatment, survival rates, and management of AEDs. METHODS: A systematic review was performed according to the PRISMA recommendations and included articles published between 1953 and 2023 describing seizures in patients with PCNSL. RESULTS: The search identified 282 studies, of which 21 were included. Up to 33% of patients with PCNSL developed seizures, mostly at the initial presentation. Little information was found on changes in seizure incidence through the course of the disease, and no details were found on seizure frequency, the percentage of treatment-resistant patients, or the evolution of seizures at remission. Younger age, cortical location, and immunodeficiency have been identified as potential risk factors for seizures, but evidence is very limited. The growing use of vigorous treatments including intensive chemotherapy with autologous stem cell transplantation and immunotherapy with CAR-T cells is associated with a higher incidence of seizures. The association between seizure development and patient mortality in PCNSL remains unknown. There are no data on AED prophylaxis or the use of specific AEDs in PCNSL. CONCLUSIONS: Further studies are needed to investigate seizures in larger cohorts of PCNSL, to clarify their prevalence, better characterize them, identify risk factors, analyze survival rates, and make recommendations on AED management. We recommend following general practice guidelines for seizures symptomatic of brain tumors and not to prescribe AED prophylaxis in PCNSL.

Cross-subject variability of the optic radiation anatomy in a cohort of 1065 healthy subjects.

INTRODUCTION: Optic radiations are tracts of particular interest for neurosurgery, especially for temporal lobe resection, because their lesion is responsible for visual field defects. However, histological and MRI studies found a high inter-subject variability of the optic radiation anatomy, especially for their most rostral extent inside the Meyer's temporal loop. We aimed to better assess inter-subject anatomical variability of the optic radiations, in order to help to reduce the risk of postoperative visual field deficiencies. METHODS: Using an advanced analysis pipeline relying on a whole-brain probabilistic tractography and fiber clustering, we processed the diffusion MRI data of the 1065 subjects of the HCP cohort. After registration in a common space, a cross-subject clustering on the whole cohort was performed to reconstruct the reference optic radiation bundle, from which all optic radiations were segmented on an individual scale. RESULTS: We found a median distance between the rostral tip of the temporal pole and the rostral tip of the optic radiation of 29.2 mm (standard deviation: 2.1 mm) for the right side and 28.8 mm (standard deviation: 2.3 mm) for the left side. The difference between both hemispheres was statistically significant (p = 1.10-8). CONCLUSION: We demonstrated inter-individual variability of the anatomy of the optic radiations on a large-scale study, especially their rostral extension. In order to better guide neurosurgical procedures, we built a MNI-based reference atlas of the optic radiations that can be used for fast optic radiation reconstruction from any individual diffusion MRI tractography.

Predictive factors of postoperative outcome in the elderly after resective epilepsy surgery.

OBJECTIVE: To evaluate the efficiency of resective epilepsy surgery (RES) in patients over 50 years and determine prognostic factors. RESULTS: Over the 147 patients over 50 years (54.9±3.8 years [50-69]) coming from 8 specialized French centres for epilepsy surgery, 72.1%, patients were seizure-free and 91.2% had a good outcome 12 months after RES. Seizure freedom was not associated with the age at surgery or duration of epilepsy. In multivariate analysis, seizure freedom was associated with MRI and neuropathological hippocampal sclerosis (HS) (P=0.009 and P=0.028 respectively), PET hypometabolism (P=0.013), temporal epilepsy (P=0.01). On the contrary, the need for intracranial exploration was associated with a poorer prognosis (P=0.001). Postoperative number of antiepileptic drugs was significantly lower in the seizure-free group (P=0.001). Neurological adverse event rate after surgery was 21.1% and 11.7% of patients had neuropsychological adverse effects overall transient. CONCLUSIONS: RES is effective procedure in the elderly. Even safe it remains at higher risk of complication and population should be carefully selected. Nevertheless, age should not be considered as a limiting factor, especially when good prognostic factors are identified.

Orchard Management and Landscape Context Mediate the Pear Floral Microbiome.

Crop-associated microbiota are a key factor affecting host health and productivity. Most crops are grown within heterogeneous landscapes, and interactions between management practices and landscape context often affect plant and animal biodiversity in agroecosystems. However, whether these same factors typically affect crop-associated microbiota is less clear. Here, we assessed whether orchard management strategies and landscape context affected bacterial and fungal communities in pear (Pyrus communis) flowers. We found that bacteria and fungi responded differently to management schemes. Organically certified orchards had higher fungal diversity in flowers than conventional or bio-based integrated pest management (IPM) orchards, but organic orchards had the lowest bacterial diversity. Orchard management scheme also best predicted the distribution of several important bacterial and fungal genera that either cause or suppress disease; organic and bio-based IPM best explained the distributions of bacterial and fungal genera, respectively. Moreover, patterns of bacterial and fungal diversity were affected by interactions between management, landscape context, and climate. When examining the similarity of bacterial and fungal communities across sites, both abundance- and taxon-related turnovers were mediated primarily by orchard management scheme and landscape context and, specifically, the amount of land in cultivation. Our study reveals local- and landscape-level drivers of floral microbiome structure in a major fruit crop, providing insights that can inform microbiome management to promote host health and high-yielding quality fruit. IMPORTANCE Proper crop management during bloom is essential for producing disease-free tree fruit. Tree fruits are often grown in heterogeneous landscapes; however, few studies have assessed whether landscape context and crop management affect the floral microbiome, which plays a critical role in shaping plant health and disease tolerance. Such work is key for identification of tactics and/or contexts where beneficial microbes proliferate and pathogenic microbes are limited. Here, we characterize the floral microbiome of pear crops in Washington State, where major production occurs in intermountain valleys and basins with variable elevation and microclimates. Our results show that both local-level (crop management) and landscape-level (habitat types and climate) factors affect floral microbiota but in disparate ways for each kingdom. More broadly, these findings can potentially inform microbiome management in orchards for promotion of host health and high-quality yields.

Sustained benefit of cognitive behaviour therapy for health anxiety in medical patients (CHAMP) over 8 years: a randomised-controlled trial.

BACKGROUND: Health anxiety is an under-recognised but a frequent cause of distress. It is particularly common in general hospitals. METHODS: We carried out an 8-year follow-up of medical out-patients with health anxiety (hypochondriasis) enrolled in a randomised-controlled trial in five general hospitals in London, Middlesex and Nottinghamshire. Randomisation was to a mean of six sessions of cognitive behaviour therapy adapted for health anxiety (CBT-HA) or to standard care in the clinics. The primary outcome was a change in score on the Short Health Anxiety Inventory, with generalised anxiety and depression as secondary outcomes. Of 444 patients aged 16-75 years seen in cardiology, endocrinology, gastroenterology, neurology and respiratory medicine clinics, 306 (68.9%) were followed-up 8 years after randomisation, including 36 who had died. The study is registered with controlled-trials.com, ISRCTN14565822. RESULTS: There was a significant difference in the HAI score in favour of CBT-HA over standard care after 8 years [1.83, 95% confidence interval (CI) 0.25-3.40, p = 0.023], between group differences in generalised anxiety were less (0.54, 95% CI -0.29 to 1.36), p = 0.20, ns), but those for depression were greater at 8 years (1.22, 95% CI 0.42-2.01, p < 0.003) in CBT-HA than in standard care, most in standard care satisfying the criteria for clinical depression. Those seen by nurse therapists and in cardiology and gastrointestinal clinics achieved the greatest gains with CBT-HA, with greater improvement in both symptoms and social function. CONCLUSIONS: CBT-HA is a highly long-term effective treatment for pathological health anxiety with long-term benefits. Standard care for health anxiety in medical clinics promotes depression. Nurse therapists are effective practitioners.

Effect of 'Candidatus Phytoplasma pruni' Infection on Sweet Cherry Fruit.

In sweet cherry (Prunus avium), infection by 'Candidatus Phytoplasma pruni' results in small fruit with poor color and taste, rendering the fruit unmarketable. Yet the disease pathology is poorly understood, particularly at the cultivar level. Therefore, in this study we examined the physiological effects of Ca. P. pruni infection across a range of cultivars and locations in eastern Washington. We found that infection could be separated into early and established stages based on pathogen titer, which correlated with disease severity, including fruit size, color, and sugar and metabolite content. Furthermore, we observed that the effects of early-stage infections were largely indistinguishable from healthy, uninfected plants. Cultivar- and location-specific disease outcomes were observed with regard to size, color, sugar content, and citric acid content. This study presents the first in-depth assessment of X-disease symptoms and biochemical content of fruit from commercially grown sweet cherry cultivars known to be infected with Ca. P. pruni.

Epilepsy and pregnancy: What should the neurologists do?

Epilepsy is one of the most common chronic disorders affecting women of childbearing age. Unfortunately, many women with epilepsy (WWE) still report not receiving key information about pregnancy. They obviously need information about epilepsy and pregnancy prior to conception with a particular emphasis on effective birth control (i.e. contraception), necessity to plan pregnancy, antiepileptic drugs optimization, and folate supplementation. The risks associated with use of antiepileptic drugs during pregnancy have to be balanced against fetal and maternal risks associated with uncontrolled seizures. This report reviews evidence-based counseling and management strategies concerning maternal and fetal risks associated with seizures, teratogenic risks associated with antiepileptic drug exposure with a special emphasis on developmental and behavioural outcomes of children exposed to intra utero antiepileptic drugs.

Early tolerability of Comirnaty vaccine in patients with chronic neurological diseases.

Patients with chronic neurological diseases may have predisposing risk factors for severe COVID-19 and should be considered as priority candidates for SARS-CoV-2 vaccination. Nevertheless, the safety of RNA vaccine was evaluated in healthy volunteers or in patients with stable chronic medical conditions excluding patients with chronic neurological diseases. We report here the early tolerability of Comirnaty vaccine in 36 patients with chronic neurological diseases and demonstrate good early tolerability, better than found in healthy people in phase 3 trials.

Nonconvulsive status epilepticus in the elderly.

There is a higher incidence of status epilepticus in the older adult population that commonly presents as nonconvulsive status epilepticus (NCSE). NCSE most often corresponds to prolonged focal seizures with impaired consciousness with three main clinical presentations: i) an unexplained acute confusional state, ii) subtle eye, motor or behavioral signs or mood changes and iii) typical temporal or frontal seizures with impaired consciousness. Focal seizures without impaired consciousness or de novo absence status of late onset may also be met. The identified risk factors for NCSE onset are: a precession by a generalized tonic-clonic seizure, a known history of epilepsy, female gender, and an acute symptomatic cause or a known brain injury (especially a stroke sequelae). Diagnosis in this population may be difficult, as the clinical presentation is often not very suggestive (stupor, confusion, even coma), and requires an unrestricted use of EEG with an EEG diagnosis based on the EEG with now accepted criteria (so-called Salzburg EEG criteria). The treatment is based first on the injection of benzodiazepines and in the second line on intravenous or oral or gastric tube administration of antiepileptic drugs. It is not recommended to resort to an intubation-ventilation (except necessary to treat respiratory distress, multi-organ failure…). Prognosis is poor with about 30% mortality.

Getting older with chronic temporal lobe epilepsy: What memory profile?

Older adults with epilepsy frequently report changes in memory function, with a concern about degenerative disease. However, the precise limit between memory changes related to the effects of longstanding chronic epilepsy and physiological aging on memory abilities is very difficult to specify. Knowledge about characteristics of physiological cognitive aging, its influence on memory test results, and its interactions with clinical variables related to epileptic disease are therefore essential to interpret memory scores. This paper aims at presenting an overview of the different factors that might modulate the developmental trajectory of episodic memory in chronic temporal lobe epilepsy. For this purpose, the effects of age on memory in healthy and epileptic persons will be first reviewed with a special focus on episodic memory functions in chronic temporal lobe epilepsy. Finally, scientific evidence supporting or not the presence of an accelerated memory decline in patients with longstanding epilepsy will be presented by discussing the interests and the limits of the existing literature. Identifying the best outcome measures to assess episodic memory and understanding the risk factors that might precipitate memory decline are key knowledge to improve the clinical care and quality of life of persons with chronic temporal lobe epilepsy.

Two viruses, MCV1 and MCV2, which infect Marinitoga bacteria isolated from deep-sea hydrothermal vents: functional and genomic analysis.

Viruses represent a driving force in the evolution of microorganisms including those thriving in extreme environments. However, our knowledge of the viral diversity associated to microorganisms inhabiting the deep-sea hydrothermal vents remains limited. The phylum of Thermotogae, including thermophilic bacteria, is well represented in this environment. Only one virus was described in this phylum, MPV1 carried by Marinitoga piezophila. In this study, we report on the functional and genomic characterization of two new bacterioviruses that infect bacteria from the Marinitoga genus. Marinitoga camini virus 1 and 2 (MCV1 and MCV2) are temperate siphoviruses with a linear dsDNA genome of 53.4 kb and 50.5 kb respectively. Here, we present a comparative genomic analysis of the MCV1 and MCV2 viral genomes with that of MPV1. The results indicate that even if the host strains come from geographically distant sites, their genomes share numerous similarities. Interestingly, heavy metals did not induce viral production, instead the host of MCV1 produced membrane vesicles. This study highlights interaction of mobile genetic elements (MGE) with their hosts and the importance of including hosts-MGEs' relationships in ecological studies.

Curcumin and fisetin internalization into Saccharomyces cerevisiae cells via osmoporation: impact of multiple osmotic treatments on the process efficiency.

Cell osmoporation is a simple and straightforward procedure of creating food-grade biocapsules. This study proposes a new protocol of sequential cell osmoporation stages and evaluates its impact on the efficiency of curcumin and fisetin internalization into Saccharomyces cerevisiae cells. To the best of our knowledge, this is the first report in the literature regarding the subject. To assess how multiple osmoporation stages influence the encapsulation efficiency (% EE), encapsulated amount of curcumin (IC) and fisetin (IF) into S. cerevisiae cells and cell viability, the residual supernatant was used for the subsequent encapsulation stages and viability was assessed by the CFU method. Quantification was carried through direct extraction, using an ultrasonic bath and UV-Vis spectrophotometry. Experimental data demonstrated that the addition of a second osmoporation stage increases both the EE (% EE) and the amount of encapsulated curcumin and fisetin (IC and IF). As a result, the EE was considerably improved and the obtained microcapsules contained a higher amount of the targeted bioactive compounds in its internal structure. However, adding a third osmoporation stage proved to less beneficial to the process efficiency due to its lower yield and the significant negative impact to cell viability. SIGNIFICANCE AND IMPACT OF THE STUDY: For the first time in the literature, a protocol of serial osmoporation stages to enhance the encapsulation efficiency of hydrophobic low molecular weight molecules (curcumin and fisetin) into Saccharomyces cerevisiae cells was determined. By increasing overall efficiency, this protocol empowers the encapsulation process and creates a rational way to reduce waste for future industrial osmoporation applications.

A clinical and neurophysiological motor signature of Unverricht-Lundborg disease.

OBJECTIVES: Unverricht-Lundborg disease (ULD) is the most common form of progressive myoclonus epilepsy. Cerebellar dysfunction may appear over time, contributing along with myoclonus to motor disability. The purpose of the present work was to clarify the motor and neurophysiological characteristics of ULD patients. METHODS: Nine patients with genetically proven ULD were evaluated clinically (medical history collected from patient charts, the Scale for the Assessment and Rating of Ataxia and Unified Myoclonus Rating Scale). Neurophysiological investigations included EEG, surface polymyography, long-loop C-reflexes, somatosensory evoked potentials, EEG jerk-locked back-averaging (JLBA) and oculomotor recordings. All patients underwent brain MRI. Non-parametric Mann-Whitney tests were used to compare ULD patients' oculomotor parameters with those of a matched group of healthy volunteers (HV). RESULTS: Myoclonus was activated by action but was virtually absent at rest and poorly induced by stimuli. Positive myoclonus was multifocal, often rhythmic and of brief duration, with top-down pyramidal temporospatial propagation. Cortical neurophysiology revealed a transient wave preceding myoclonus on EEG JLBA (n=8), enlarged somatosensory evoked potentials (n=7) and positive long-loop C-reflexes at rest (n=5). Compared with HV, ULD patients demonstrated decreased saccadic gain, increased gain dispersion and a higher frequency of hypermetric saccades associated with decreased peak velocity. CONCLUSION: A homogeneous motor pattern was delineated that may represent a ULD clinical and neurophysiological signature. Clinical and neurophysiological findings confirmed the pure cortical origin of the permanent myoclonus. Also, oculomotor findings shed new light on ULD pathophysiology by evidencing combined midbrain and cerebellar dysfunction.

Rates of serum level determinations of antiepileptic drugs in accord with guidelines: A clinical study at a tertiary center.

OBJECTIVE: To compare our rates of appropriate therapeutic drug monitoring (TDM) with those defined in the French guidelines for measuring drug levels of antiepileptic drugs (AEDs) during the pre- and post-medical/pharmaceutical interventional periods. METHODS: This study was prospectively carried out at a tertiary center (epilepsy unit of the Pitié-Salpêtrière Hospital in Paris) between 2013 and 2016 over three time periods. Criteria for appropriateness were those stated in the current French guidelines. The main outcome measure was the percentage of drug level measurements with an appropriate indication, while a second outcome measure was the impact of education on clinical practice. RESULTS: Of the 698 AED level measurements requested, 84% overall were found to have appropriate indications ranging from 75% to 90%, according to French guideline criteria. Rates of appropriate indications for the three most commonly used individual AEDs-valproate, carbamazepine and lamotrigine-were 79.6%, 77.3% and 90.7%, respectively, whereas the requests considered to not have an appropriate indication involved the majority (63.5%) of cases of routine drug monitoring. In addition, dedicated education seems to substantially increase rates of appropriateness. CONCLUSION: At our center, 84% of AED level determinations had an appropriate indication according to a priori defined and reliable criteria. Moreover, it was noted that a specific educational intervention substantially increased rates of appropriateness. Thus, it appears to be crucial to ensure that medical and paramedical staff are aware of the official recommendations to avoid taking unnecessary drug level measurements.

Cerebral venous thrombosis at high altitude: A systematic review.

BACKGROUND AND OBJECTIVE: High altitude may be a factor associated with cerebral venous thrombosis (CVT). As our knowledge of CVT at high altitude is limited, it was decided to pool such information from the available case studies to determine whether high altitude can predispose to CVT. METHODS: A systematic review of the literature was performed for cases reporting CVT at high altitude. Searches of the PubMed database (up to July 2016) were performed for publications, using 'cerebral venous thrombosis' and 'high altitude' as keywords. Cross-referencing was also done to complete the search. RESULTS: Ultimately, 13 articles were included in our systematic review. The population consisted of 17 patients, predominately male (14/17), with a mean age of 32 (range: 19-47) years. Altitude range was 3000-8200m. Nine patients stayed at high altitude for>2 weeks; the duration of high altitude stay was unknown for the remainder. A hypercoagulable state was found in nine patients: secondary polycythemia in five; protein C deficiency in one; protein S deficiency in one; and factor V Leiden mutations in two. No comorbidities were found in any of these patients. CONCLUSION: Long-term stays at high altitude in association with a hypercoagulable state - in particular, congenital or acquired thrombophilia - appears to predispose to CVT. The association of CVT with a single exposure to high altitude seems low, but the risk cannot as yet be specifically estimated.

Relationship between invasion success and colony breeding structure in a subterranean termite.

Factors promoting the establishment and colonization success of introduced populations in new environments constitute an important issue in biological invasions. In this context, the respective role of pre-adaptation and evolutionary changes during the invasion process is a key question that requires particular attention. This study compared the colony breeding structure (i.e. number and relatedness among reproductives within colonies) in native and introduced populations of the subterranean pest termite, Reticulitermes flavipes. We generated and analysed a data set of both microsatellite and mtDNA loci on termite samples collected in three introduced populations, one in France and two in Chile, and in the putative source population of French and Chilean infestations that has recently been identified in New Orleans, LA. We also provided a synthesis combining our results with those of previous studies to obtain a global picture of the variation in breeding structure in this species. Whereas most native US populations are mainly composed of colonies headed by monogamous pairs of primary reproductives, all introduced populations exhibit a particular colony breeding structure that is characterized by hundreds of inbreeding reproductives (neotenics) and by a propensity of colonies to fuse, a pattern shared uniquely with the population of New Orleans. These characteristics are comparable to those of many invasive ants and are discussed to play an important role during the invasion process. Our finding that the New Orleans population exhibits the same breeding structure as its related introduced populations suggests that this native population is pre-adapted to invade new ranges.