Early use of MRI improves diagnostic accuracy in young adults with stroke

ObjectivesThe misdiagnosis of acute ischemic stroke in young adults is a significant problem since patients may have many decades of potential disability. Also, proven therapies for acute stroke may not be administered if there is an initial misdiagnosis. We assessed the hypothesis that early use of MRI, arrival by ambulance, and presentation to a Primary Stroke Center (PSC) would be associated with a reduced rate of misdiagnosis.MethodsA prospective database of young adults (ages 16–49 years) with ischemic stroke (final diagnosis provided by vascular neurologists) was reviewed. We collected information on several variables, including age, race, arrival by ambulance, whether brain MRI was performed within 48 h, and initial presentation to a PSC. Variables were tested against emergency department (ED) misdiagnosis using univariate and multivariate methods.Results77 patients with a mean age of 37.9 years were reviewed. 48.3% of patients arrived by ambulance, 53.2% had a brain MRI within 48 h, and 23.4% initially presented to a PSC. The overall rate of ED misdiagnosis was 14.5%. In multivariate testing, performance of MRI within 48 h (p = 0.023) was associated with a lower rate of misdiagnosis and age < 35 years was linked with greater likelihood of misdiagnosis (p = 0.047).ConclusionsEarly performance of MRI leads to greater accuracy of stroke diagnosis in young adults presenting to the ED. Patients less than age 35 years have a greater risk of misdiagnosis. ED physicians and neurologists should consider early use of MRI in young adults with stroke-like deficits and diagnostic uncertainty.     

A review of the mechanisms and effectiveness of dietary polyphenols in reducing oxidative stress and thrombotic risk

Dietary sources of polyphenols, which are derivatives and/or isomers of flavones, isoflavones, flavonols, catechins and phenolic acids, possess antioxidant properties and therefore might be important in preventing oxidative‐stress‐induced platelet activation and attenuating adverse haemostatic function. Free radicals, including reactive oxygen and nitrogen species, promote oxidative stress, leading to platelet hyperactivation and the risk of thrombosis. The consumption of antioxidant/polyphenol rich foods might therefore impart anti‐thrombotic and cardiovascular protective effects via their inhibition of platelet hyperactivation or aggregation. Most commonly‐used anti‐platelet drugs such as aspirin block the cyclooxygenase (COX)‐1 pathway of platelet activation, similar to the action of antioxidants with respect to neutralising hydrogen peroxide (H₂O₂), with a similar effect on thromboxane production via the COX‐1 pathway. Polyphenols also target various additional platelet activation pathways (e.g. by blocking platelet‐ADP, collagen receptors); thus alleviating fibrinogen binding to platelet surface (GPIIb‐IIIa) receptors, reducing further platelet recruitment for aggregation and inhibiting platelet degranulation. As a result of the ability of polyphenols to target additional pathways of platelet activation, they may have the potential to substitute or complement currently used anti‐platelet drugs in sedentary, obese, pre‐diabetic or diabetic populations who can be resistant or sensitive to pharmacological anti‐platelet therapy.     

A relational database for trial-based behavioral experiments

We describe a relational database (RDB) structure suitable for trial-based experiments such as human psychophysics and neural recording studies in trained animals. An RDB is a collection of tables, each composed of columns. Some of the tables contain columns that reference specific columns of other tables. This referencing system links the tables to each other and makes it possible to extract any subset of the data with trivial commands. An equally important advantage of an RDB is that it imposes a consistent data format on applications that generate and analyze data. The result is a centralization and standardization of data storage that facilitates the pooling, cross-checking and re-analysis of data from various experiments. We present a robust RDB structure originally designed for neurophysiological data; however, it is abstract enough to accommodate data from a variety of trial-based experimental designs. Moreover, we demonstrated the advantages of this RDB structure and indicated its implementation in other laboratories.     

Experimental transmission of foot-and-mouth disease among Indian buffalo (Bubalus bubalis) and from buffalo to cattle

Indian buffalo and cattle were infected experimentally with a serotype O strain of foot-and-mouth disease virus of buffalo origin. Whereas intradermolingual inoculation of buffalo produced largely sub-clinical infection, inoculation in the dental pad produced vesicles in the mouth and on the feet. A buffalo infected via the dental pad transmitted infection to cattle and buffalo by direct contact with them for 24h. The contact-exposed buffalo developed (1) delayed-onset clinical signs, and (2) shedding of virus from the nose, commencing before the appearance of vesicles and continuing until the experiment was terminated 10 weeks after exposure. The covert nature of the disease in Indian buffalo, coupled with the prolonged shedding of virus, suggests that this species represents a host of epidemiological importance.     

Converging early responses to brain injury pave the road to epileptogenesis

Epilepsy, characterized by recurrent seizures and abnormal electrical activity in the brain, is one of the most prevalent brain disorders. Over two million people in the United States have been diagnosed with epilepsy and 3% of the general population will be diagnosed with it at some point in their lives. While most developmental epilepsies occur due to genetic predisposition, a class of “acquired” epilepsies results from a variety of brain insults. A leading etiological factor for epilepsy that is currently on the rise is traumatic brain injury (TBI), which accounts for up to 20% of all symptomatic epilepsies. Remarkably, the presence of an identified early insult that constitutes a risk for development of epilepsy provides a therapeutic window in which the pathological processes associated with brain injury can be manipulated to limit the subsequent development of recurrent seizure activity and epilepsy. Recent studies have revealed diverse pathologies, including enhanced excitability, activated immune signaling, cell death, and enhanced neurogenesis within a week after injury, suggesting a period of heightened adaptive and maladaptive plasticity. An integrated understanding of these processes and their cellular and molecular underpinnings could lead to novel targets to arrest epileptogenesis after trauma. This review attempts to highlight and relate the diverse early changes after trauma and their role in development of epilepsy and suggests potential strategies to limit neurological complications in the injured brain.     

Primary intracranial plasma cell granulomas presenting as malignant neoplasms

Plasma cell granuloma (PCG) is an uncommon non-neoplastic mass lesion of unknown etiology. It is characterized by a polyclonal proliferation of chronic inflammatory cells, mostly mature plasma and other mononuclear cells. PCGs arising in the central nervous system are particularly rare. We report two additional cases of intracranial PCG exclusively involving the brain parenchyma. A 47 year-old woman, presenting with partial motor seizures and fluent aphasia, underwent complete excision of a well-demarcated, enhancing left parietal mass. The second patient was a 56 year-old man presenting with headaches and right-sided weakness who underwent stereotactic biopsy of an ill-defined, heterogeneously enhancing lesion in the left basal ganglia. Immunohistochemical analysis of surgical specimens showed polyclonal plasma cells and mature lymphocytes but no etiological agent. A histopathologic diagnosis of intracranial PCG was made in both cases. PCG should be part of the differential diagnosis of enhancing mass lesions of the brain. The etiology and natural history of these tumor-like lesions is not fully understood. Complete surgical excision appears to be curative. Lesions where total resection is not possible may benefit from adjuvant treatment including corticosteroids and possibly radiation therapy.