bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Potassium Concentration on Firing Patterns of Low‐Calcium Epileptiform Activity in Anesthetized Rat Hippocampus: Inducing of Persistent Spike Activity
Authors: Feng Zhouyan , Durand Dominique M. 
Published: April 2006

Summary:  Purpose: It has been shown that a low‐calcium high‐potassium solution can generate ictal‐like epileptiform activity in vitro and in vivo. Moreover, during status epileptiform activity, the concentration of [K+]o increases, and the concentration of [Ca2+]o decreases in brain tissue. Therefore we tested the hypothesis that long‐lasting persistent spike activity, similar to one of the patterns of status epilepticus, could be generated by a high‐potassium, low‐calcium solution in the hippocampus in vivo. Methods: Artificial cerebrospinal fluid was perfused over the surface of the exposed left dorsal hippocampus of anesthetized rats. A stimulating electrode and a recording probe were placed in the CA1 region. Results: By elevating K+ concentration from 6 to 12 mM in the perfusate solution, the typical firing pattern of low‐calcium ictal bursts was transformed into persistent spike activity in the CA1 region with synaptic transmission being suppressed by calcium chelator EGTA. The activity was characterized by double spikes repeated at a frequency ∼4 Hz that could last for >1 h. The analysis of multiple unit activity showed that both elevating [K+]o and lowering [Ca2+]o decreased the inhibition period after the response of paired‐pulse stimulation, indicating a suppression of the after‐hyperpolarization (AHP) activity. Conclusions: These results suggest that persistent status epilepticus–like spike activity can be induced by nonsynaptic mechanisms when synaptic transmission is blocked. The unique double‐spike pattern of this activity is presumably caused by higher K+ concentration augmenting the frequency of typical low‐calcium nonsynaptic burst activity.
Differential Actions of NPY on Seizure Modulation via Y1 and Y2 Receptors: Evidence from Receptor Knockout Mice
Authors: Deborah Lin En‐Ju , Young Deborah , Baer Kristin , Herzog Herbert , During Matthew J. 
Published: April 2006

Summary:  Purpose: Neuropeptide Y (NPY) has been shown to modulate seizure activities. To provide further understanding of the involvement of two of the most abundantly expressed NPY receptors, Y1 and Y2, we assessed the effect of Y1 and Y2 gene deletion on systemic kainic acid–induced seizures. We also examined the effect of rAAV‐mediated hippocampal NPY overexpression on seizure susceptibility in these receptor knockout mice. Methods: Recombinant adeno‐associated viral vector overexpressing NPY (rAAV‐NPY) or an empty vector control (rAAV‐Empty) was injected into the hippocampus of adult C57BL/6–129/SvJ wild‐type male mice and mice deficient of Y1 or Y2 receptors on the same background. Four weeks after vector injection, mice were subjected to systemic kainic acid–induced seizures, and the seizure behaviors were scored. Results: The rAAV‐mediated hippocampal overexpression of NPY led to a twofold reduction in seizures induced by systemic kainic acid in wild‐type mice and Y1 receptor knockout mice but not in mice deficient of Y2 receptors. A differential action by the receptors was observed in the seizure‐induced mortality rate, with increased fatality in Y2−/− mice. In addition, although NPY overexpression did not significantly affect the mortality rate in Y2−/− and wild‐type mice, it abolished KA‐induced mortality in Y1−/−mice. Conclusions: This study shows for the first time an altered susceptibility to chemically induced seizures in Y1 and Y2 knockout mice and demonstrates a differential seizure modulation mediated by these receptors via a genetic approach.
Retinal Nerve Fiber Layer and Macular Thickness in Adolescents with Epilepsy Treated with Valproate and Carbamazepine
Authors: Lobefalo Lucio , Rapinese Marcello , Altobelli Emma , Di Mascio Raffaella , Lattanzi Daniela , Gallenga Pier Enrico , Chiarelli Francesco , Verrotti Alberto 
Published: April 2006

Summary:  Purpose: To evaluate retinal nerve retinal nerve fiber layer (RNFL) and macular thickness by using optical coherence tomography (OCT) in epileptic adolescents before and during monotherapy with valproic acid (VPA) and carbamazepine (CBZ). Methods: We examined prospectively 45 epilepsy patients with partial and generalized epilepsy. The patients were evaluated before the beginning of therapy and after 1 year of VPA or CBZ monotherapy. Forty‐five untreated healthy controls were evaluated at baseline and after 1 year. Results: At the beginning of the study, the two groups of patients showed RNFL and macular thickness measurements similar to control values. At the end of the follow‐up, the data of the three groups were similar to baseline, showing no significant differences in the evaluated parameters. Conclusions: The present study demonstrates that no modification of RNFL and macular thickness parameters is found after 1 year of treatment with VPA and CBZ monotherapy.
Distinct Cognitive Neurophysiologic Profiles for Lamotrigine and Topiramate
Authors: Smith Michael E. , Gevins Alan , McEvoy Linda K. , Meador Kimford J. , Ray Patricia G. , Gilliam Frank 
Published: April 2006

Summary:  Purpose: To contrast the effects of lamotrigine (LTG) and topiramate (TPM) on cognitive task‐related and resting‐state EEG and evoked potential (EP) measures. Methods: We used a double‐blind, randomized, crossover design. Healthy adults (N = 29) had two 8‐week periods of dose escalation, 4 weeks of drug maintenance (300 mg daily), and 4 weeks of washout. EEG was recorded during working memory (WM) tasks and resting conditions at baseline, at the end of each maintenance phase, and after final washout. Results. LTG did not affect overt performance on the tasks, although it reduced EEG power in both resting and WM task conditions, most prominently in the 6‐ to 12‐Hz frequency range, and attenuated P300 evoked‐potential amplitude equally in both WM task loads. TPM slowed responses and increased errors. It also increased EEG power below 6 Hz in all conditions, and reduced the amplitude of a slow wave observed in a difficult version of the WM task. Conclusions: The drugs produced both task‐independent and task‐related alterations in neurophysiologic measures. The EEG and EP changes produced by TPM are consistent with an impairment of WM, as evidenced by overt performance deficits on the behavioral tasks. By contrast, the reduction in synchronous cortical activity produced by LTG was not accompanied by cognitive impairment. It is unknown whether such effects would also be observed at lower doses, such as those that often are used in monotherapy for newly diagnosed patients.
The Ictal Bradycardia Syndrome: Localization and Lateralization
Authors: Britton Jeffrey W. , Ghearing Gena R. , Benarroch Eduardo E. , Cascino Gregory D. 
Published: April 2006

Summary: Purpose:Previous studies have established the importance of the insular cortex and temporal lobe in cardiovascular autonomic modulation. Some investigators, based on the results of cortical stimulation response, functional imaging, EEG recordings of seizures, and lesional studies, have suggested that cardiac sympathetic and parasympathetic function may be lateralized, with sympathetic representation lateralized to the right insula, and parasympathetic, to the left. These studies have suggested that ictal bradycardia is most commonly a manifestation of activation of the left temporal and insular cortex. However, the evidence for this is inconsistent. We sought to assess critically the predictable value of ictal bradycardia for seizure localization and lateralization.Methods:In this study, we reviewed the localization of seizure activity in 13 consecutive patients with ictal bradycardia diagnosed during prolonged video‐EEG monitoring at Mayo Clinic Rochester. The localization of electrographic seizure activity at seizure onset and bradycardia onset was identified in all patients. In addition, we performed a comprehensive review of the ictal bradycardia literature focusing on localization of seizure activity in ictal bradycardia cases.Results:All occurrences of ictal bradycardia in the 13 identified patients were associated with temporal lobe–onset seizures. However, no consistent lateralization of seizure activity was found at onset of seizure activity or at onset of bradycardia in this population. Seizure activity was bilateral at bradycardia onset in nine of 13 patients. The results from the literature review also showed that a predominance of patients had bilateral activity at bradycardia onset; however, more of the ictal bradycardia cases from the literature had left hemispheric localization of seizure onset.Conclusions:Ictal bradycardia most often occurs in association with bilateral hemispheric seizure activity and is not a consistent lateralizing sign in localizing seizure onset. Our data do not support the existence of a strictly unilateral parasympathetic cardiomotor representation in the left hemisphere, as has been suggested.
EEG Dipole Characteristics in Panayiotopoulos Syndrome
Authors: Yoshinaga Harumi , Koutroumanidis Michael , Kobayashi Katsuhiro , Shirasawa Atsushi , Kikumoto Kenichi , Inoue Takushi , Oka Makio , Ohtsuka Yoko 
Published: April 2006

Summary: Purpose:Panayiotopoulos syndrome (PS) is a type of benign childhood partial epilepsy that is frequently associated with abundant multifocal spikes other than main occipital spikes on the EEG. In this study, we investigated the characteristic features of dipoles in PS.Methods:We performed dipole analysis of the interictal occipital spike discharges seen in 10 children with PS (group A) and in 10 children with other types of symptomatic localization‐related epilepsy (group B). We analyzed the dipoles of the averaged spike in each patient.Results:In group A, the averaged occipital spikes in each patient showed dense dipole locations in the mesial occipital area; in group B, widely scattered dipole locations were observed. In Group A, the geometric centers of the dipoles at each time point (such as at the main negative peak and before or after the main peak) were estimated in the neighboring locations. In contrast, they tended to be scattered in group B.Conclusions:Our study reveals that PS has high dipole stability, similar to that of rolandic epilepsy. From the electroencephalographic view, this seems to indicate a close link between these two syndromes.
MRI Volumetry and Proton MR Spectroscopy of the Brain in Lafora Disease
Authors: Villanueva Vicente , Alvarez‐Linera Juan , Gómez‐Garre Pilar , Gutiérrez Jorge , Serratosa José M. 
Published: April 2006

Summary:  Purpose: To determine brain involvement in Lafora disease by means of 3‐T MRI volumetry and 1H magnetic resonance (MR) spectroscopy. Methods: Ten patients with Lafora disease and 10 healthy controls were included in the study. The diagnosis of Lafora disease was proven genetically by the presence of mutations in the EPM2A gene in all patients, and their evolution was staged in three groups according to their functional state. MRI volumetry was performed by means of AX3DT1 images with assessment of the cerebellum and the brainstem, by using the program Stereonauta, and all the brain structures, by using voxel‐based morphometry. [1H]MR spectroscopy was performed by using an Eclipse PRESS sequence probe system with 8‐cc voxels positioned in the occipital and frontal cortexes, basal ganglia, pons, and cerebellar hemispheres. Spectral peak areas corresponding to NAA (N‐acetylaspartate), creatine, and choline were obtained. Results: MRI volumetry showed no statistically significant differences in patients compared with healthy controls in any of the analyzed structures. Analysis of [1H]MR spectroscopy data showed a statistically significant reduction in the NAA/creatine ratio in patients compared with controls in the frontal (p = 0.001) and occipital cortex (p = 0.043), basal ganglia (p = 0.002), and cerebellar hemispheres (p = 0.007). The NAA/choline and choline/creatine ratios were statistically significantly different in the frontal cortex (p = 0.005). No correlation was observed between the disease‐evolution stage and MRI‐measured volumes (range, –0.92 to 0.44) or [1H]MR spectroscopy values (range, –0.29 to 0.50). Conclusions: In our series of Lafora disease patients, [1H]MR spectroscopy was more sensitive than structural MRI to detect brain involvement. The brain cortex, especially frontal cortex, cerebellum, and basal ganglia, showed the greatest metabolic changes.
Transient Athetosis Induced by Tiagabine
Authors: Tombini Mario , Pacifici Loredana , Passarelli Francesco , Rossini Paolo M. 
Published: April 2006

Summary:  Movement disorders have been reported with use of different antiepileptic drugs (AEDs). We report a 32‐year‐old woman, affected by a symptomatic focal drug‐resistant epilepsy and a mild hemiparesis, with acute athetoid movements, transiently linked to increasing tiagabine (TGB) therapy. To our knowledge, no other cases of acute athetosis related to TGB have been reported to date. However, we cannot rule out the possibility that involuntary movements were induced by an interaction between TGB and concomitant AEDs, in particular phenobarbital (PB), possibly by increasing GABAergic transmission.We hypothesize that the presence of a static encephalopathy may have influenced the kind of extrapyramidal side effect induced by TGB in our patient, leading to athetosis.
Risk Stratification of Individuals with the Brugada Electrocardiogram: A Meta‐Analysis
Authors: GEHI ANIL K. , DUONG TRUONG D. , METZ LOUISE D. , GOMES J. ANTHONY , MEHTA DAVENDRA 
Published: April 2006

Objectives: We performed a meta‐analysis of prognostic studies of patients with a Brugada ECG to assess predictors of events. Background: The Brugada syndrome is an increasingly recognized cause of idiopathic ventricular fibrillation; however, there is wide variation in the prognosis of patients with the Brugada ECG. Methods and Results: We retrieved 30 prospective studies of patients with the Brugada ECG, accumulating data on 1,545 patients. Summary estimates of the relative risk (RR) of events (sudden cardiac death [SCD], syncope, or internal defibrillator shock) for a variety of potential predictors were made using a random‐effects model. The overall event rate at an average of 32 months follow‐up was 10.0% (95% CI 8.5%, 11.5%). The RR of an event was increased (P < 0.001) among patients with a history of syncope or SCD (RR 3.24 [95% CI 2.13, 4.93]), men compared with women (RR 3.47 [95% CI 1.58, 7.63]), and patients with a spontaneous compared with sodium‐channel blocker induced Type I Brugada ECG (RR 4.65 [95% CI 2.25, 9.58]). The RR of events was not significantly increased in patients with a family history of SCD (P = 0.97) or a mutation of the SCN5A gene (P = 0.18). The RR of events was also not significantly increased in patients inducible compared with noninducible by electrophysiologic study (EPS) (RR 1.88 [95% CI 0.62, 5.73], P = 0.27); however, there was significant heterogeneity of the studies included. Conclusions: Our findings suggest that a history of syncope or SCD, the presence of a spontaneous Type I Brugada ECG, and male gender predict a more malignant natural history. Our findings do not support the use of a family history of SCD, the presence of an SCN5A gene mutation, or EPS to guide the management of patients with a Brugada ECG.
Characteristics of Slow Pathway Conduction After Successful AVNRT Ablation
Authors: POSAN EMOKE , GULA LORNE J. , SKANES ALLAN C. , KRAHN ANDREW D. , YEE RAYMOND , PETRELLIS BASILIOS , REDFEARN DAMIAN P. , MOHAMED UWAIS , GOULD PAUL A. , KLEIN GEORGE J. 
Published: April 2006

Background: AV node slow pathway conduction can persist following successful ablation for AV node reentrant tachycardia (AVNRT). We hypothesized that careful examination of AV nodal conduction curves before and after effective AVNRT ablation in patients with persistent slow pathway conduction could shed light on this apparent paradox. Methods and Results: Thirty patients (age 40.9 ± 14.3; 8 male) were included. AV node function curves were created based on pre‐ and postablation atrial extrastimulus testing. Analysis of slow pathway function curves demonstrated significant decrease in AH for any given coupling interval after ablation (mean difference –68.1 [–94.5, –41.7] P < 0.001), graphically indicated by downward displacement of the curve. In addition, mean slow pathway effective refractory period (ERP) increased from 247.9 ± 36.1 msec to 288.6 ± 56.0 msec (P < 0.001); mean maximum AH interval decreased from 361.3 ± 114.2 msec to 306.9 ± 65.2 msec (P = 0.013); mean difference in minimum and maximum AH interval during slow pathway conduction decreased (from 94.5 ± 75.8 msec to 59.6 ± 46.2 msec (P = 0.016). Finally, mean difference between the fast and slow pathway effective refractory periods, the span of coupling intervals over which slow pathway conduction occurred, decreased (from 113.9 ± 61.4 msec to 63.2 ± 41.5 msec, P = 0.001). Conclusions: Ablation, which successfully eliminates inducible and spontaneous AVNRT in the presence of persistent slow pathway conduction, is associated with significantly altered slow pathway conduction characteristics, indicating the presence of a damaged or different slow pathway after ablation, incapable of sustaining tachycardia.
Two‐Year Follow‐up of Sirolimus‐Eluting Stents for the Treatment of Proximal Left Anterior Descending Coronary Artery Stenosis
Authors: VALENCIA JOSÉ , BERENGUER ALBERTO , MAINAR VICENTE , BORDES PASCUAL , GÓMEZ SILVIA , TELLO ANTONIO , LÓPEZ‐ARANDA MIGUEL ÁNGEL , CATURLA JUAN 
Published: April 2006

Introduction: Sirolimus‐eluting stents (SES) have demonstrated low target vessel revascularizations and low incidence of angiographic restenosis in several clinical scenarios. The aim of the present study was to assess the efficacy and safety of SES for the treatment of proximal left anterior descending coronary artery (pLAD) lesions.
Methods: Ninety‐six patients with severe pLAD stenosis were enrolled. Angiographic and clinical follow‐up were performed at 6 and 24 months, respectively. Death, myocardial infarction (MI), new target lesion revascularization (TLR), and target vessel failure (TVF) were registered. Clinical, angiographic, and procedural variables were analyzed to identify predictors of restenosis.
Results: Mean clinical follow‐up was 858 ± 158 days (26.5 ± 8.3 months). Angiographic procedural success was 100%. Angiographic follow‐up showed 8.4% of binary restenosis without edge‐restenosis phenomenon. Late loss was 0.15 ± 0.65 mm; 15.6% of patients had an adverse cardiac event, with 1% of death, 5.2% of MI, 6.3% of TLR, and 9.4% of TVF. At 2 years, the probabilities of cumulative TVF‐ and TLR‐free survival were 90.6% and 93.7%, respectively. Interestingly, no adverse cardiac events were registered between the first and second years. Female gender (OR 10.7 CI 95%[1.7–66.7]) and in‐stent restenosis (OR 8.2, CI 95%[1.2–56.4]) were found as independent predictors of binary restenosis.
Advanced chronic renal failure showed a strong trend toward worse outcome in terms of binary restenosis (P = 0.063).
Conclusions: SES for the treatment of pLAD stenosis proved safe and effective in a long‐term follow‐up with low incidence of adverse cardiac events and restenosis. Female gender and in‐stent restenosis were predictors of binary restenosis.
Usefulness of Fractional Flow Reserve in Multivessel Coronary Artery Disease with Intermediate Lesions
Authors: JIMÉNEZ‐NAVARRO MANUEL F. , ALONSO‐BRIALES JUAN , HERNÁNDEZ‐GARCÍA JOSÉ MARÍA , CURIEL EMILIO , KÜHLMORGEN BIRGIT , GÓMEZ‐DOBLAS JUAN JOSÉ , GARCÍA‐PINILLA JOSÉ MANUEL , ROBLEDO JUAN , DE TERESA EDUARDO 
Published: April 2006

Background: Calculation of myocardial fractional flow reserve (FFR) enables coronary stenoses to be evaluated.
Objectives: We determined the usefulness of measuring the FFR in multivessel coronary artery disease, reflected in changes in the therapeutic options for patients with moderate coronary stenosis.
Methods: We studied 38 patients (30 men, 8 women; mean age: 59.8 ± 10 years) with multivessel coronary artery disease with 41 moderate lesions. Indications for coronary angiography were unstable angina in 24 patients (60%), acute myocardial infarction in 10 (27%), and stable angina in 4 (13%). We studied the FFR (in nonactive lesions) in the left anterior descending artery in 23 patients (56%), the left coronary trunk in 8 (19.5%), the circumflex artery in 5 (12.2%), the right coronary artery in 3 (7.3%), and the left internal mammary artery and diagonal branch in 1 patient each.
Results: Twelve patients had a positive FFR, which resulted in no change in the mode of revascularization; 26 patients had a negative FFR, in 20 (77%) of whom the revascularization approach was changed, especially those with moderate lesions of the left coronary trunk or anterior descending artery. No differences were detected in the angiographic characteristics of the lesions examined. Cardiac events during follow‐up were few.
Conclusions: The results of FFR may influence the decision‐making process after diagnostic coronary angiography in multivessel coronary artery disease with moderate lesions, especially in patients with a negative FFR in nonculprit lesions of the left trunk or left anterior descending artery.
Tropical Forests of Xishuangbanna, China1
Authors: Cao Min , Zou Xiaoming , Warren Matthew , Zhu Hua 
Published: April 2006

ABSTRACTLowland tropical forests once covered a large fraction of tropical southern China, but currently have an extent of ca 633,800 ha, mostly in Xishuangbanna of southern Yunnan. The Xishuangbanna region has a typical monsoon climate with a mean annual temperature ranging between 15.1°C and 21.7°C, and precipitation between 1200 and 2500 mm. There is a pronounced dry season between November and April with frequent occurrence of heavy fog. Rainfall during the wet season between May and October accounts for over 80 percent of total annual precipitation. Water deposition from fog accounts for over one‐third of total water input during the dry season in the forests, suggesting an important role that fog may play in pushing up the northern limit of tropical rain forest in Southeast Asia.
Forest Structure and Biomass of a Tropical Seasonal Rain Forest in Xishuangbanna, Southwest China1
Authors: Zheng Zheng , Feng Zhili , Cao Min , Li Zhongfei , Zhang Jianhou 
Published: April 2006

ABSTRACTXishuangbanna is a region located at the northern edge of tropical Asia. Biomass estimates of its tropical rain forest have not been published in English literature. We estimated forest biomass and its allocation patterns in five 0.185–1.0 ha plots in tropical seasonal rain forests of Xishuangbanna. Forest biomass ranged from 362.1 to 692.6 Mg/ha. Biomass of trees with diameter at 1.3 m breast height (DBH) ≥ 5 cm accounted for 98.2 percent of the rain forest biomass, followed by shrubs (0.9%), woody lianas (0.8%), and herbs (0.2%). Biomass allocation to different tree components was 68.4–70.0 percent to stems, 19.8–21.8 percent to roots, 7.4–10.6 percent to branches, and 0.7–1.3 percent to leaves. Biomass allocation to the tree sublayers was 55.3–62.2 percent to the A layer (upper layer), 30.6–37.1 percent to the B layer (middle), and 2.7–7.6 percent to the C layer (lower). Biomass of Pometia tomentosa, a dominant species, accounted for 19.7–21.1 percent of the total tree biomass. The average density of large trees (DBH ≥100 cm) was 9.4 stems/ha on two small plots and 3.5 stems/ha on two large plots, illustrating the potential to overestimate biomass on a landscape scale if only small plots are sampled. Biomass estimations are similar to typical tropical rain forests in Southeast Asia and the Neotropics.