Effects of some novel anticonvulsant drugs on the synchronous activity recorded in the presence of 4-aminopyridine in the rat hippocampus

Despite advances in understanding the pathogenesis of epilepsy, it remains a significant therapeutic challenge. Studies of the novel antiepileptic drugs (AEDs) gabapentin, lamotrigine and topiramate suggest that they will aid in managing seizures refractory to more established agents. However, a consensus has not been reached on their respective cellular and molecular mechanisms of action. Moreover, only a limited number of studies have examined the effects of these drugs in infants and children, a patient population with a particular propensity for seizure generation. Therefore, the objective of this investigation was to assess the effects of these new AEDs on the synchronous epileptiform activity evoked by the convulsant 4-aminopyridine (4AP) in the immature brain. The experiments described in this thesis indicate that at clinically relevant concentrations, gabapentin, lamotrigine and topiramate effectively reduce epileptiform events induced by 4AP in the hippocampal slice in vitro. These findings support previous work, and will be relevant for designing future antiepileptic compounds

Explorations in the use of augmented reality for geographic visualization

In this paper we describe two explorations in the use of hybrid user interfaces for collaborative geographic data visualization. Our first interface combines three technologies; Augmented Reality (AR), immersive Virtual Reality and computer vision based hand and object tracking. Wearing a lightweight display with camera attached, users can look at a real map and see three-dimensional virtual terrain models overlaid on the map. From this AR interface they can fly in and experience the model immersively, or use free hand gestures or physical markers to change the data representation. Building on this work, our second interface explores alternative interface techniques, including a zoomable user interface, paddle interactions and pen annotations. We describe the system hardware and software, and the implications for GIS and spatial science applications

Comparative study of posterior and anterior circulation stroke in childhood: Results from the International Pediatric Stroke Study.

ObjectiveTo compare risk factors, clinical presentation, and outcomes after posterior circulation arterial ischemic stroke (PCAIS) and anterior circulation arterial ischemic stroke (ACAIS) in neonates and children.MethodsIn this international multicenter observational study including neonates and children up to 18 years of age with arterial ischemic stroke (AIS), we compared clinical and radiologic features according to stroke location.ResultsOf 2,768 AIS cases, 507 (18%) were located in the posterior circulation, 1,931 (70%) in the anterior circulation, and 330 (12%) involved both. PCAIS was less frequent in neonates compared to children (8.8% vs 22%, p < 0.001). Children with PCAIS were older than children with ACAIS (median age 7.8 [interquartile range (IQR) 3.1-14] vs 5.1 [IQR 1.5-12] years, p < 0.001), and more often presented with headache (54% vs 32%, p < 0.001) and a lower Pediatric NIH Stroke Scale score (4 [IQR 2-8] vs 8 [IQR 3-13], p = 0.001). Cervicocephalic artery dissections (CCAD) were more frequent (20% vs 8.5%, p < 0.001), while cardioembolic strokes were less frequent (19% vs 32%, p < 0.001) in PCAIS. Case fatality rates were equal in both groups (2.9%). PCAIS survivors had a better outcome (normal neurologic examination at hospital discharge in 29% vs 21%, p = 0.002) than ACAIS survivors, although this trend was only observed in children and not in neonates.ConclusionPCAIS is less common than ACAIS in both neonates and children. Children with PCAIS are older and have a higher rate of CCAD, lower clinical stroke severity, and better outcome than children with ACAIS

Comparative study of posterior and anterior circulation stroke in childhood: Results from the International Pediatric Stroke Study.

OBJECTIVE To compare risk factors, clinical presentation, and outcomes after posterior circulation arterial ischemic stroke (PCAIS) and anterior circulation arterial ischemic stroke (ACAIS) in neonates and children. METHODS In this international multicenter observational study including neonates and children up to 18 years of age with arterial ischemic stroke (AIS), we compared clinical and radiologic features according to stroke location. RESULTS Of 2,768 AIS cases, 507 (18%) were located in the posterior circulation, 1,931 (70%) in the anterior circulation, and 330 (12%) involved both. PCAIS was less frequent in neonates compared to children (8.8% vs 22%, p < 0.001). Children with PCAIS were older than children with ACAIS (median age 7.8 [interquartile range (IQR) 3.1-14] vs 5.1 [IQR 1.5-12] years, p < 0.001), and more often presented with headache (54% vs 32%, p < 0.001) and a lower Pediatric NIH Stroke Scale score (4 [IQR 2-8] vs 8 [IQR 3-13], p = 0.001). Cervicocephalic artery dissections (CCAD) were more frequent (20% vs 8.5%, p < 0.001), while cardioembolic strokes were less frequent (19% vs 32%, p < 0.001) in PCAIS. Case fatality rates were equal in both groups (2.9%). PCAIS survivors had a better outcome (normal neurologic examination at hospital discharge in 29% vs 21%, p = 0.002) than ACAIS survivors, although this trend was only observed in children and not in neonates. CONCLUSION PCAIS is less common than ACAIS in both neonates and children. Children with PCAIS are older and have a higher rate of CCAD, lower clinical stroke severity, and better outcome than children with ACAIS

Management of Stroke in Neonates and Children: A Scientific Statement From the American Heart Association/American Stroke Association.

Purpose- Much has transpired since the last scientific statement on pediatric stroke was published 10 years ago. Although stroke has long been recognized as an adult health problem causing substantial morbidity and mortality, it is also an important cause of acquired brain injury in young patients, occurring most commonly in the neonate and throughout childhood. This scientific statement represents a synthesis of data and a consensus of the leading experts in childhood cardiovascular disease and stroke. Methods- Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association's Manuscript Oversight Committee and were chosen to reflect the expertise of the subject matter. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge. This scientific statement is based on expert consensus considerations for clinical practice. Results- Annualized pediatric stroke incidence rates, including both neonatal and later childhood stroke and both ischemic and hemorrhagic stroke, range from 3 to 25 per 100 000 children in developed countries. Newborns have the highest risk ratio: 1 in 4000 live births. Stroke is a clinical syndrome. Delays in diagnosis are common in both perinatal and childhood stroke but for different reasons. To develop new strategies for prevention and treatment, disease processes and risk factors that lead to pediatric stroke are discussed here to aid the clinician in rapid diagnosis and treatment. The many important differences that affect the pathophysiology and treatment of childhood stroke are discussed in each section. Conclusions- Here we provide updates on perinatal and childhood stroke with a focus on the subtypes, including arterial ischemic, venous thrombotic, and hemorrhagic stroke, and updates in regard to areas of childhood stroke that have not received close attention such as sickle cell disease. Each section is highlighted with considerations for clinical practice, attendant controversies, and knowledge gaps. This statement provides the practicing provider with much-needed updated information in this field

Seizures and Outcome One Year After Neonatal and Childhood Cerebral Sinovenous Thrombosis

BackgroundPediatric cerebral sinovenous thrombosis is a treatable cause of brain injury, acute symptomatic seizures, and remote epilepsy. Our objective was to prospectively study epilepsy and outcomes in neonates and children one year after cerebral sinovenous thrombosis diagnosis.MethodsPatients with cerebral sinovenous thrombosis were enrolled prospectively from 21 international sites through the Seizures in Pediatric Stroke Study. Clinical data, including acute symptomatic seizures and cerebral sinovenous thrombosis risk factors, were collected at diagnosis. A neuroradiologist who was unaware of the diagnosis reviewed acute imaging. At one year, outcomes including seizure recurrence, epilepsy diagnosis, antiepileptic drug use, and modified Engel score were collected. Outcomes were assessed using the modified Rankin score and the King's Outcome Scale for Childhood Head Injury.ResultsTwenty-four participants with cerebral sinovenous thrombosis were enrolled (67% male, 21% neonates). Headache was the most common presenting symptom in non-neonates (47%, nine of 19). Nine (37.5%) presented with acute symptomatic seizures. Six (25%; 95% confidence interval,&nbsp;10% to 47%) developed epilepsy by one-year follow-up. No clinical predictors associated with epilepsy were identified. King's Outcome Scale for Childhood Head Injury and modified Rankin scores at one year were favorable in 71%. Half of the patients who developed epilepsy (three of six) did not have infarcts, hemorrhage, or seizures identified during the acute hospitalization.ConclusionOur study provides a prospective estimate that epilepsy occurs in approximately one-quarter of patients by one year after diagnosis of cerebral sinovenous thrombosis. Later epilepsy can develop in the absence of acute seizures or parenchymal injury associated with the acute presentation