Subarachnoid hemorrhage mimicking an acute migraine attack: A case report.

Subarachnoid hemorrhage is a neurological emergency in which arterial blood accumulates in the subarachnoid space with cerebral aneurysmal rupture being the most common cause. Subarachnoid hemorrhage is often misdiagnosed in the emergency department and mortality rates range from 8% to 67%. It may be the manifestation of the chronicity of the migraine. The difference in severity or quality compared to previous headaches, and other symptoms, particularly neck stiffness, but also seizure, syncope, focal neurological deficit, and vomiting are the key factors differentiating subarachnoid hemorrhage from the migraine. We report a case of a 37-year-old female with a previous history of migraines who presented with acute onset of excruciating headaches in the occiput associated with nausea, vomiting, and photophobia in whom a non-contrast computed tomography scan of the head showed hyper-densities involving the bilateral cerebral cortical sulcus and Sylvian fissure and the cerebral angiography showed a complex aneurysm in anterior communicating artery.

A rare case of schwannomatosis with meningioma: a case report.

Introduction: Schwannomatosis is characterized by multiple schwannomas without vestibular schwannomas or any other stigmata of neurofibromatosis type 2 (NF2). Schwannomatosis is a rare disorder, with a reported incidence ranging from 1 in 40 000 to 1 in 1.7 million. Meningioma is also associated with schwannomatosis in around 5% of cases. Case presentation: We describe a case of a 20-year-old female presenting with progressive weakness of the right lower limb for 7 months with a tingling sensation and numbness of the same limb for 6 months and was found to have schwannomatosis with multiple spinal and right cerebellopontine angle (CPA) (9th/10th cranial nerve) schwannomas and left anterior cranial fossa meningioma. Discussion: Schwannomas in schwannomatosis are seen along the cranial, spinal, and peripheral nerves but not along the vestibular nerve, as is characteristically seen in NF2. The occurrence of meningiomas is about 5% in individuals with schwannomatosis, and the patient in our case also had an associated meningioma. The tumor was confirmed to be a schwannoma based on features on an MRI examination and histological examination. Conclusion: It is of great significance to identify the entire spectrum of the disease in a patient with schwannomatosis, and to differentiate it from related conditions in order to track and surgically manage the patient appropriately based on symptomatology and imaging findings.

Endovascular treatment of subdural haematoma in patient under anti-platelet therapy: a case report.

Introduction: The incidence of chronic subdural haematoma (cSDH) is relatively high among the elderly population. Other known risk factors for cSDH include male sex, dependency on anti-platelet or anticoagulant medication, and chronic alcoholism. Although, the standard mode of treatment for cSDH is surgery, embolization of the middle meningeal artery (MMA), either upfront or as an adjunct to surgical evacuation can be used for the treatment of cSDH. Case presentation: The authors present a case of a 75-year-old female with prior history of posterior-lateral wall myocardial infarction (MI) eight years back presented to our centre with the chief complaints of a gradual onset of cough and headache for 2 months. The patient had no history of trauma, loss of consciousness, seizures, and vomiting. There was no history of diabetes, hypertension, pulmonary tuberculosis, and other chronic illness. Discussion: The concurrent use of anti- platelet drug during a surgical procedure can make the treatment challenging. Endovascular treatment can be a primary treatment modality in such situation. Conclusion: Elimination of blood supply by middle meningeal artery embolization is emerging as a safe, minimally invasive alternative to treat cSDH.

Remote Sensing Data to Detect Hessian Fly Infestation in Commercial Wheat Fields.

Remote sensing data that are efficiently used in ecological research and management are seldom used to study insect pest infestations in agricultural ecosystems. Here, we used multispectral satellite and aircraft data to evaluate the relationship between normalized difference vegetation index (NDVI) and Hessian fly (Mayetiola destructor) infestation in commercial winter wheat (Triticum aestivum) fields in Kansas, USA. We used visible and near-infrared data from each aerial platform to develop a series of NDVI maps for multiple fields for most of the winter wheat growing season. Hessian fly infestation in each field was surveyed in a uniform grid of multiple sampling points. For both satellite and aircraft data, NDVI decreased with increasing pest infestation. Despite the coarse resolution, NDVI from satellite data performed substantially better in explaining pest infestation in the fields than NDVI from high-resolution aircraft data. These results indicate that remote sensing data can be used to assess the areas of poor growth and health of wheat plants due to Hessian fly infestation. Our study suggests that remotely sensed data, including those from satellites orbiting >700 km from the surface of Earth, can offer valuable information on the occurrence and severity of pest infestations in agricultural areas.

Cosmopolitan Species As Models for Ecophysiological Responses to Global Change: The Common Reed Phragmites australis.

Phragmites australis is a cosmopolitan grass and often the dominant species in the ecosystems it inhabits. Due to high intraspecific diversity and phenotypic plasticity, P. australis has an extensive ecological amplitude and a great capacity to acclimate to adverse environmental conditions; it can therefore offer valuable insights into plant responses to global change. Here we review the ecology and ecophysiology of prominent P. australis lineages and their responses to multiple forms of global change. Key findings of our review are that: (1) P. australis lineages are well-adapted to regions of their phylogeographic origin and therefore respond differently to changes in climatic conditions such as temperature or atmospheric CO2; (2) each lineage consists of populations that may occur in geographically different habitats and contain multiple genotypes; (3) the phenotypic plasticity of functional and fitness-related traits of a genotype determine the responses to global change factors; (4) genotypes with high plasticity to environmental drivers may acclimate or even vastly expand their ranges, genotypes of medium plasticity must acclimate or experience range-shifts, and those with low plasticity may face local extinction; (5) responses to ancillary types of global change, like shifting levels of soil salinity, flooding, and drought, are not consistent within lineages and depend on adaptation of individual genotypes. These patterns suggest that the diverse lineages of P. australis will undergo intense selective pressure in the face of global change such that the distributions and interactions of co-occurring lineages, as well as those of genotypes within-lineages, are very likely to be altered. We propose that the strong latitudinal clines within and between P. australis lineages can be a useful tool for predicting plant responses to climate change in general and present a conceptual framework for using P. australis lineages to predict plant responses to global change and its consequences.

Geographic variation in apparent competition between native and invasive Phragmites australis.

Apparent competition, the negative interaction between species mediated by shared natural enemies, is thought to play an important role in shaping the structure and dynamics of natural communities. However, its importance in driving species invasions, and whether the strength of this indirect interaction varies across the latitudinal range of the invasion, has not been fully explored. We performed replicated field experiments at four sites spanning 900 km along the Atlantic Coast of the United States to assess the presence and strength of apparent competition between sympatric native and invasive lineages of Phragmites australis. Four herbivore guilds were considered: stem-feeders, leaf-miners, leaf-chewers and aphids. We also tested the hypothesis that the strength of this interaction declines with increasing latitude. Within each site, native and invasive plants of P. australis were cross-transplanted between co-occurring native and invasive patches in the same marsh habitat and herbivore damage was evaluated at the end of the growing season. Apparent competition was evident for both lineages and involved all but the leaf-chewer guild. For native plants, total aphids per plant was 296% higher and the incidence of stem-feeding and leaf-mining herbivores was 34% and 221% higher, respectively, when transplanted into invasive than native patches. These data suggest that invasive P. australis has a negative effect on native P. australis via apparent competition. Averaged among herbivore types, the indirect effects of the invasive lineage on the native lineage was 57% higher than the reverse situation, suggesting that apparent competition was asymmetric. We also found that the strength of apparent competition acting against the native lineage was comparable to the benefits to the invasive lineage from enemy release (i.e., proportionately lower mean herbivory of the invasive relative to the native taxa). Finally, we found the first evidence that the strength of apparent competition acting against the native lineage (from stem-feeders only) decreased with increasing latitude. These results suggest that not only could apparent competition be of tantamount importance to enemy release in enhancing the establishment and spread of invasive taxa, but also that these indirect and direct herbivore effects could vary over the invasion range.

Biogeography of a plant invasion: plant-herbivore interactions.

Theory predicts that native plant species should exhibit latitudinal gradients in the strength of their interactions with herbivores. We hypothesize that if an invasive plant species exhibits a different latitudinal gradient in response to herbivores (e.g., a nonparallel gradient), it can create large-scale heterogeneities in community resistance/susceptibility to the invasive species. We conducted a study of latitudinal variation in the strength of herbivory and defenses of native genotypes of Phragmites australis in North America (NA) and Europe (EU) and European invasive genotypes in NA. Within NA, we tested whether (1) invasive genotypes are better defended and suffer less herbivory than co-occurring native genotypes, (2) herbivory and defenses of native P. australis decreases with increasing latitude; and (3) invasive genotypes exhibit either no latitudinal gradient, or a nonparallel latitudinal gradient in herbivory and defenses compared to native genotypes. For the European genotypes, we tested two additional hypotheses: (4) defenses, nutritional condition, and herbivory would differ between the native (EU) and invasive ranges (NA) and (5) latitudinal gradients in defenses and herbivory would be similar between ranges. Within NA, chewing damage, internal stem-feeding incidence, and aphid abundance were 650%, 300%, and 70% lower, respectively, on invasive than native P. australis genotypes. Genotypes in NA also differed in nutritional condition (percent N, C:N ratio), but there was little support for invasive genotypes being better defended than native genotypes. For the European genotypes, herbivory was significantly lower in the invaded than native range, supporting the enemy-release hypothesis. Defense levels (leaf toughness and total phenolics) and tissue percent C and percent N were higher in the invaded than native range for European genotypes. Overall, latitudinal gradients in P. australis nutritional condition, defenses, and herbivory were common. Interestingly, chewing damage and stem-feeder incidence decreased with latitude for native P. australis genotypes in NA and EU, but no latitudinal gradients in response to herbivores were evident for invasive genotypes in NA. Nonparallel latitudinal gradients in herbivory between invasive and native P. australis suggest that the community may be more susceptible to invasion at lower than at higher latitudes. Our study points to the need for invasion biology to include a biogeographic perspective.

Hurricane activity and the large-scale pattern of spread of an invasive plant species.

Disturbances are a primary facilitator of the growth and spread of invasive species. However, the effects of large-scale disturbances, such as hurricanes and tropical storms, on the broad geographic patterns of invasive species growth and spread have not been investigated. We used historical aerial imagery to determine the growth rate of invasive Phragmites australis patches in wetlands along the Atlantic and Gulf Coasts of the United States. These were relatively undisturbed wetlands where P. australis had room for unrestricted growth. Over the past several decades, invasive P. australis stands expanded in size by 6-35% per year. Based on tropical storm and hurricane activity over that same time period, we found that the frequency of hurricane-force winds explained 81% of the variation in P. australis growth over this broad geographic range. The expansion of P. australis stands was strongly and positively correlated with hurricane frequency. In light of the many climatic models that predict an increase in the frequency and intensity of hurricanes over the next century, these results suggest a strong link between climate change and species invasion and a challenging future ahead for the management of invasive species.