Seizure outcome after epilepsy surgery in tuberous sclerosis complex: Results and analysis of predictors from a multicenter study.

Epilepsy surgery is recommended in selected patients with Tuberous Sclerosis Complex (TSC). However, reports on predictive factors of seizure outcome are variable. Here we report on seizure and cognitive outcome of 35 TSC patients who received surgery for refractory epilepsy in 7 Italian centers over a period of 22 years (1997-2019). The rate of seizure-free individuals at last follow-up (mean 7.5 years, range 1-21 years) was 51%. Patients with longer follow-up (≥10 years) had a lower rate of Engel I outcome (11.1%) than those who received surgery in the last 10 years (65.4%, p = 0.003). Factors associated with Engel II, III, IV outcome in our cohort included: high number of cortical tubers (≥5); presence of subependymal nodules (SENs); seizure onset before age 1 year; and multifocal interictal epileptic discharges (IEDs) on electroencephalogram (EEG). A subset of patients evaluated with Vineland Adaptive Behaviour Scales (VABS) showed developmental gains, in line with their developmental trajectories, but no improvement in standard scores after surgery was noted. Our study demonstrates that the rates of successful seizure outcome of epilepsy surgery in TSC have improved in the last 10 years. More than half of the patients achieved seizure freedom, and a high proportion of affected individuals experienced a reduction in seizure burden and in antiseizure medications. A comprehensive assessment after surgery should be performed in TSC patients to evaluate the overall neurodevelopmental outcome, as measures that are based only on seizure control do not adequately identify the benefits of surgery on global functioning in these patients.

Pravastatin acute neuroprotective effects depend on blood brain barrier integrity in experimental cerebral ischemia.

Statins have since long been reported to exert acute neuroprotection in experimental stroke models. However, crucial questions still need to be addressed as far as the timing of their cerebral effects after intravascular administration and the role played by the blood brain barrier (BBB) crossing properties. We tested the effects of an hydrophilic statin (pravastatin, 100 nM), which poorly crosses BBB under physiological conditions. Pravastatin was administered either 90 min before or immediately after transient middle cerebral artery occlusion in the in vitro isolated guinea pig brain preparation. A multi-modal outcome assessment was performed, through electrophysiological and cerebral vascular tone recordings, MAP-2 immunohistochemistry, BBB evaluation via ZO-1/FITC-albumin analysis, AKT and ERK activation and whole-cell antioxidant capacity. Pravastatin pre-ischemic administration did not produce any significant effect. Pravastatin post-ischemic administration significantly prevented MAP-2 immunoreactivity loss in ischemic areas, increased ERK phosphorylation in the ischemic hemisphere and enhanced whole-cell antioxidant capacity. Electrophysiological parameters, vascular tone and AKT signaling were unchanged. In all tested ischemic brains, ZO-1 fragmentation and FITC albumin extravasation was observed, starting 30 min from ischemia onset, indicating loss of BBB integrity. Our findings indicate that the rapid anti-ischemic effects of intravascular pravastatin are highly dependent on BBB increased permeability after stroke.

Accuracy of transcranial ultrasound in the detection of mild white matter lesions in newborns.

Cranial Ultrasound (cUS) may not be sensitive enough to detect subtle white matter (WM) injuries. Our study compared serial cUS with MRI at term equivalent age (TEA) to determine if it is possible to identify an ultrasound representation of subtle diffuse WM injuries such as punctate lesions (PWMLs) and diffuse excessive high signal intensity (DEHSI). Fifty-six very preterm infants were scanned sequentially from birth to TEA, an MRI was performed at TEA. Each echodensity found on cUS was classified as absent, transient (≤7 days), or prolonged (>7 days). A transient periventricular echodensity was detected in seven infants (12.5%), and a prolonged echodensity in 15 (26.8%). MRI examinations were performed in all 56 infants. No altered signal intensity was found in 18 infants (32.1%). DEHSI was detected in 14 infants (25%), and PWMLs were detected in eight babies (14.3%). Both abnormalities were found in 16 infants (28.6%). The positive predictive values of the prolonged echodensity for DEHSI and PWMLs were 86.7% and 46.7% respectively. However, a significant statistical correspondence (p=0.002, Odds Ratio 11.9) was found comparing DEHSI with cUS abnormal echodensities. Serial cUS during the neonatal period in preterm infants is essential and cannot be replaced with MRI at TEA. MRI seems to be more reliable in detecting mild or moderate WM abnormalities. However, serial cUS performed by an experienced neonatologist can provide valuable information on early WM changes such as prolonged echodensities that could potentially lead to a diffuse injury.

Acute lipophilicity-dependent effect of intravascular simvastatin in the early phase of focal cerebral ischemia.

The acute effects of simvastatin lactone (lipophilic) and simvastatin acid (hydrophilic) on transient focal ischemia were assessed using the isolated guinea pig brain maintained in vitro by arterial perfusion. This new model of cerebral ischemia allows the assessment of the very early phase of the ischemic process, with the functional preservation of the vascular and neuronal compartments and the blood-brain barrier (bbb). The middle cerebral artery was transiently tied for 30 min followed by reperfusion for 60 min. Statins (nanomolar doses) were administered by intravascular continuous infusion starting 60 min before ischemia induction. Brain cortical activity and arterial vascular tone were continuously recorded. At the end of the experiment immunoreactivity for microtubule-associated protein 2 (MAP-2), expression of survival kinases (ERK and Akt) and total anti-oxidant capacity were assayed. Brains treated with simvastatin lactone showed i) reduced amplitude and delayed onset of ischemic depressions, ii) preservation of MAP-2 immunoreactivity, iii) activation of ERK signaling in the ischemic hemisphere and iv) increase in whole-brain anti-oxidant capacity. Treatment with the bbb-impermeable simvastatin acid was ineffective on the above-mentioned parameters. Vascular resistance recordings and Akt signaling were unchanged by any statin treatment. Our findings suggest that intravascular-delivered simvastatin exerts an acute lipophilicity-dependent protective effect in the early phase of cerebral ischemia.

[Macrosomic infants: clinical problems at birth and afterward]. / I macrosomi: problemi clinici alla nascita e a distanza.

Macrosomic infants (birth weight >4000 g) show increased risk for shoulder dystocia and associated injuries, hypoglycemia and respiratory distress. Higher risk is directly related to neonatal birth weight. High birth weight is also associated with increased risk of developing metabolic syndrome later in life. However the relation between birth weight and later-life metabolic syndrome in not linear, but "U" shaped.

[The contribution of enteral nutrition in the premature infant]. / Apporti nutrizionali enterali nel pretermine.

In recent years, improvements in obstetrical and neonatal care have significantly improved survival in preterm and, particularily, the very low birth weight infant. Several studies stress the importance of timely and adequate nutrition in these high-risk infants on a short- and long-term. Presently, there is little consensus among the neonatologists concerning the optimal way to initiate, advance or maintain enteral feeding in preterm Infants. The preferred food for premature infants is fortified milk from the infant's own mother or,alternatively, formula designed for premature infants. The recent guidelines proposed by ESPGHAN Committee on Nutrition provide minimal and maximal levels of intake for individual macro- and micro-nutrients.

Enteral nutrient supply for preterm infants: commentary from the European Society of Paediatric Gastroenterology, Hepatology and Nutrition Committee on Nutrition.

The number of surviving children born prematurely has increased substantially during the last 2 decades. The major goal of enteral nutrient supply to these infants is to achieve growth similar to foetal growth coupled with satisfactory functional development. The accumulation of knowledge since the previous guideline on nutrition of preterm infants from the Committee on Nutrition of the European Society of Paediatric Gastroenterology and Nutrition in 1987 has made a new guideline necessary. Thus, an ad hoc expert panel was convened by the Committee on Nutrition of the European Society of Paediatric Gastroenterology, Hepatology, and Nutrition in 2007 to make appropriate recommendations. The present guideline, of which the major recommendations are summarised here (for the full report, see http://links.lww.com/A1480), is consistent with, but not identical to, recent guidelines from the Life Sciences Research Office of the American Society for Nutritional Sciences published in 2002 and recommendations from the handbook Nutrition of the Preterm Infant. Scientific Basis and Practical Guidelines, 2nd ed, edited by Tsang et al, and published in 2005. The preferred food for premature infants is fortified human milk from the infant's own mother, or, alternatively, formula designed for premature infants. This guideline aims to provide proposed advisable ranges for nutrient intakes for stable-growing preterm infants up to a weight of approximately 1800 g, because most data are available for these infants. These recommendations are based on a considered review of available scientific reports on the subject, and on expert consensus for which the available scientific data are considered inadequate.

Risk factors associated with Cryptosporidium parvum infection in cattle.

A 2-year, cross-sectional study was conducted to identify risk factors for Cryptosporidium sp. infection in bovine farms in central Italy. Faecal samples were collected on 248 farms, from 2024 calves and analysed using ELISA and immunofluorescent assay (IFA) commercial kits. In all 101 samples confirmed to be positive with IFA, the aetiological agent was identified as Cryptosporidium parvumand a large genetic variability was detected by subtype analysis. The prevalence of farm infection ranged from 3.4% to 35.6%. Univariate analysis showed a number of putative risk factors, including the type of farm, stalling of calves, late supply of colostrum, number of heads and contact between calves and adults. However, multivariate analysis confirmed that the higher risk for calves was associated with housing calves separately from their dams, a characteristic practice of dairy herd, whereas calves being nursed by their dams, a characteristic of cow-calf herd resulted as a protective factor.

Acute induction of epileptiform discharges by pilocarpine in the in vitro isolated guinea-pig brain requires enhancement of blood-brain barrier permeability.

Systemic application of the muscarinic agonist, pilocarpine, is commonly utilized to induce an acute status epilepticus that evolves into a chronic epileptic condition characterized by spontaneous seizures. Recent findings suggest that the status epilepticus induced by pilocarpine may be triggered by changes in the blood-brain barrier (BBB) permeability. We tested the role of the BBB in an acute pilocarpine model by using the in vitro model brain preparation and compared our finding with in vivo data. Arterial perfusion of the in vitro isolated guinea-pig brain with <1 mM pilocarpine did not cause epileptiform activity, but rather reduced synaptic transmission and induced steady fast (20-25 Hz) oscillatory activity in limbic cortices. These effects were reversibly blocked by co-perfusion of the muscarinic antagonist atropine sulfate (5 microM). Brain pilocarpine measurements in vivo and in vitro suggested modest BBB penetration. Pilocarpine induced epileptiform discharges only when perfused with compounds that enhance BBB permeability, such as bradykinin (n=2) or histamine (n=10). This pro-epileptic effect was abolished when the BBB-impermeable muscarinic antagonist atropine methyl bromide (5 microM) was co-perfused with histamine and pilocarpine. In the absence of BBB permeability enhancing drugs, pilocarpine induced epileptiform activity only after arterial perfusion at concentrations >10 mM. Ictal discharges correlated with a high intracerebral pilocarpine concentration measured by high pressure liquid chromatography. We propose that acute epileptiform discharges induced by pilocarpine treatment in the in vitro isolated brain preparation are mediated by a dose-dependent, atropine-sensitive muscarinic effect promoted by an increase in BBB permeability. Pilocarpine accumulation secondary to BBB permeability changes may contribute to in vivo ictogenesis in the pilocarpine epilepsy model.

Pravastatin in vivo reduces mononuclear cell migration through endothelial monolayers.

The objective was to evaluate pravastatin modulation on peripheral blood mononuclear cell (PBMC) migration across endothelial monolayers. Eleven hypercholesterolaemic patients were treated with pravastatin 20 mg/day. At baseline (T0), after 40 days (T40) and after 6 months (T 6 months) of treatment total serum cholesterol, low-density lipoprotein (LDL), high-density lipoprotein, triglycerides, C-reactive protein, as well as tumour necrosis factor-alpha (TNF-alpha) and metalloproteinases-9 plasma levels were evaluated. At the same time points the effect of pravastatin on migration of PBMCs through a monolayer of murine brain endothelial cells was studied both in basal conditions and after endothelial stimulation with recombinant mouse TNF-alpha 10 ng/ml for 24 h. Seven volunteers were used as healthy controls. Significant decreases in total cholesterol, LDL and triglycerides as well as inhibition of transmigration were observed. PBMCs transmigration in patients prior to pravastatin therapy was higher than in healthy controls. These results suggest that pravastatin could be of benefit in a spectrum of diseases characterised by extravasation of PBMCs into the central nervous system.

Olfactory bulb networks revealed by lateral olfactory tract stimulation in the in vitro isolated guinea-pig brain.

Olfactory information processing is mediated by synaptic connections between the olfactory bulbs (OBs) and piriform-limbic cortices. Limited accessibility using common in vivo and in vitro preparations has hindered previous attempts to define these synaptic interactions. We utilized the isolated guinea-pig brain preparation to overcome these experimental limitations. Previous studies demonstrated extensive functional preservation in this preparation maintained in vitro by arterial perfusion. Field potential laminar profiles were performed with multi-channel probes in the OB following stimulation of both the lateral olfactory tract (LOT) and the anterior piriform cortex (APC). Current-source density analysis was carried out on laminar profiles to reconstruct current sinks/sources associated with intrinsic synaptic activities. LOT stimulation induced sequentially i) an antidromic population spike (at 2.66+/-0.39 ms) located in the mitral cell layer that was resistant to 100 Hz high-frequency stimulation (HFS) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) (10 microM), ii) a component located in the external plexiform layer at 3.85+/-0.63 ms that was unaffected by HFS, iii) a large amplitude potential (peak amplitude at 5.84+/-0.58 ms) generated in the external plexiform layer, abolished by HFS and CNQX, but not by bicuculline (50 microM), iv) a late response (onset at 20.00+/-2.94 ms) abolished by CNQX and enhanced by bicuculline. Stimulation of the APC also induced a late potential abolished by HFS and CNQX. Both APC-evoked and late LOT-evoked responses were abolished by a transverse cut to separate OB from APC. These results demonstrate in an isolated mammalian brain preparation the presence of reciprocal synaptic interactions between the OB and piriform cortical structures.

Realistic modeling of entorhinal cortex field potentials and interpretation of epileptic activity in the guinea pig isolated brain preparation.

Mechanisms underlying epileptic activities recorded from entorhinal cortex (EC) were studied through a computational model based on review of cytoarchitectonic and neurobiological data about this structure. The purpose of this study is to describe and use this model to interpret epileptiform discharge patterns recorded in an experimental model of ictogenesis (guinea pig isolated brain perfused with bicuculline). A macroscopic modeling approach representing synaptic interactions between cells subpopulations in the EC was chosen for its adequacy to mimic field potentials reflecting overall dynamics rising from interconnected cells populations. Therefore intrinsic properties of neurons were not included in the modeling design. Model parameters were adjusted from an identification procedure based on quantitative comparison between real and simulated signals. For both EC deep and superficial layers, results show that the model generates very realistic signals regarding temporal dynamics, spectral features, and cross-correlation values. These simulations allowed us to infer information about the evolution of synaptic transmission between principal cell and interneuronal populations and about connectivity between deep and superficial layers during the transition from background to ictal activity. In the model, this transition was obtained for increased excitation in deep versus superficial layers. Transitions between epileptiform activities [interictal spikes, fast onset activity (25 Hz), ictal bursting activity] were explained by changes of parameters mainly related to GABAergic interactions. Notably, the model predicted an important role of GABAa,fast- and GABAb-receptor-mediated inhibition in the generation of ictal fast onset and burst activities, respectively. These findings are discussed with respect to experimental data.

Activation of cerebral endothelium is required for mononuclear cell recruitment in a novel in vitro model of brain inflammation.

Brain inflammation is a common event in the pathogenesis of several neurological diseases. It is unknown whether leukocyte/endothelium interactions are sufficient to promote homing of blood-borne cells into the brain compartment. The role of mononuclear cells and endothelium was analyzed in a new experimental model, the isolated guinea-pig brain maintained in vitro by arterial perfusion. This preparation allows one to investigate early steps of brain inflammation that are impracticable in vivo. We demonstrate by confocal microscopy analysis that in vitro co-perfusion of pro-inflammatory agents and pre-activated fluorescent mononuclear cells induced endothelial expression of selectins and intracellular adhesion molecule-1 in correspondence of arrested mononuclear cells, and correlates with a moderate increase in blood-brain barrier permeability. Separate perfusion of pro-inflammatory agents and mononuclear cells induced neither mononuclear cell adhesion nor adhesion molecule expression. We demonstrate that co-activation of mononuclear cells and cerebral endothelium is an essential requirement for cell arrest and adhesion in the early stages of experimental cerebral inflammation.

Do interictal spikes sustain seizures and epileptogenesis?

Interictal spiking is seen in the EEG of epileptic patients between seizures. To date, the roles played by interictal events in seizure occurrence and in epileptogenesis remain elusive. While interictal spikes may herald the onset of electrographic seizures, experimental data indicate that hippocampus-driven interictal events prevent seizure precipitation. Even less clear than the role of interictal events in seizure occurrence is whether and how interictal spikes contribute to epileptogenesis. Thus, while plastic changes within limbic neuronal networks may result from ongoing interictal activity, experimental evidence supports the view that epileptogenesis is accompanied by a decrease in hippocampus-driven interictal activity.