Multimodality imaging for focus localization in pediatric pharmacoresistant epilepsy.

Multiple structural and functional imaging modalities are available to localize the epileptogenic focus. In pre-surgical evaluation of children with pharmacoresistant epilepsy, investigations with the maximum yield should be considered in order to reduce the complexity of the workup. OBJECTIVE: To determine the extent to which PET, ictal/interictal SPECT and its co-registration with the patient's MRI contributes to correct localization of the epileptogenic focus, surgical intervention and to the post surgical outcome in paediatric patients. METHODS: The study population included children and adolescents with pharmacoresistant epilepsy (n = 50) who underwent preoperative evaluation, surgery and had postoperative follow-up for at least 12 months. Outcome was measured by postoperative seizure frequency using Engel's classification. RESULTS: Thirty-nine patients (78%) became completely seizure free after surgical intervention. The likelihood to benefit from surgical treatment was significantly higher if localization with more imaging modalities (MRI, PET, SPECT) were concordant with respect to the resected brain area (p < 0.01). Preoperative PET examination provided better localizing information in patients with extratemporal epilepsy and/or dysplastic lesions, whereas SPECT was found to be superior to PET in patients with temporal lobe epilepsy and/or tumors (p < 0.05). No significant difference was noted in the surgical outcome in younger or older age group, in children with or without special education needs. CONCLUSION: In paediatric epilepsy pre-surgical evaluation, the combined use of multiple functional imaging modalities for a precise localisation of the epileptogenic focus is worthwhile for both extratemporal and temporal lobe epilepsy, also when EEG and MRI alone are non-contributive, given the potential benefit of complete postoperative seizure control.     

Anesthesia and the developing brain: a way forward for clinical research

It is now well established that many general anesthetics have a variety of effects on the developing brain in animal models. In contrast, human cohort studies show mixed evidence for any association between neurobehavioural outcome and anesthesia exposure in early childhood. In spite of large volumes of research, it remains very unclear if the animal studies have any clinical relevance; or indeed how, or if, clinical practice needs to be altered. Answering these questions is of great importance given the huge numbers of young children exposed to general anesthetics. A recent meeting in Genoa brought together researchers and clinicians to map a path forward for future clinical studies. This paper describes these discussions and conclusions. It was agreed that there is a need for large, detailed, prospective, observational studies, and for carefully designed trials. It may be impossible to design or conduct a single study to completely exclude the possibility that anesthetics can, under certain circumstances, produce long‐term neurobehavioural changes in humans; however , observational studies will improve our understanding of which children are at greatest risk, and may also suggest potential underlying etiologies, and clinical trials will provide the strongest evidence to test the effectiveness of different strategies or anesthetic regimens with respect to better neurobehavioral outcome.     

Asthma exacerbation is associated with particulate matter source factors in children in New York City

Exposure to fine particulate matter (PM_2.5) is linked with asthma exacerbation; however, the role played by specific PM sources is not well understood. Our objective was to investigate the associations between daily cough and wheeze symptoms in a panel of asthmatic children and PM source factors determined by receptor modeling using positive matrix factorization (PMF). We studied 36 children with moderate-to-severe asthma in New York City over both a warm and a cold season. Exposure to ambient air pollutants, including PM_2.5 elements and elemental and organic carbon fractions, was characterized. The mean ambient PM_2.5 concentration for the study periods was 12.0?±?6.7 μg/m³. Six factors were resolved using PMF, including oil, road dust, ships, regional, salt, and traffic. When adjusted for ozone, cough and wheeze symptoms were most strongly associated with the regional and salt factors. Results using tracer elements (as determined from PMF analyses) showed some inconsistency, with two tracers for road dust (K and Si) showing associations in opposite directions to each other. Positive associations were also observed for S, which is a tracer of regional PM. Significant negative associations were observed for the oil factor and one of its tracers (Zn). Mostly nonsignificant associations were found for carbon fractions, with the exception of pyrolized carbon and two elemental carbon fractions. Our results indicate that asthma symptoms are associated with regional and salt factors. In this study, the regional factor was comprised of sulfate as well as carbon-containing PM, the latter which is likely derived from both anthropogenic and biogenic sources.     

Comparison between clonidine and epinephrine admixture to lidocaine in brachial plexus block.

The admixture of clonidine or epinephrine to lidocaine for brachial plexus block was studied with regard to duration of block, postoperative analgesia, and plasma concentrations of lidocaine. Thirty-three patients of ASA physical status I and II received an admixture of either clonidine (150 micrograms; n = 15) or epinephrine (200 micrograms; n = 18) to 40 mL of 1% lidocaine in a randomized, double-blind fashion. Bone surgery predominated in those patients receiving clonidine and soft-tissue surgery in those receiving epinephrine (P less than 0.05). Onset and duration of block were not different between the groups. With the admixture of clonidine, fewer patients were completely pain free for greater than 12 h (13.3%) and pain scores (visual analogue scale 0-10) were higher 6 h after the block (median 4; range 0-6) than with epinephrine (61.1%; median 2; range 0-7, respectively; P less than 0.05). In patients who had received clonidine, peak plasma concentrations of lidocaine were higher (10.29 +/- 2.96 mumol/L) and occurred earlier (23.7 +/- 9.3 min; mean +/- SD) than in those treated with epinephrine (6.9 +/- 1.71 mumol/L; 72.5 +/- 56.2 min; P less than 0.05). This indicates the absence of a local vasoconstrictor effect of clonidine and implies a reduced margin of safety with regard to local anesthetic toxicity. Although clonidine does not offer advantages compared with epinephrine, it may be a useful adjunct to local anesthetics in those patients in whom the administration of epinephrine is contraindicated.     

Talus bipartitus

Talus bipartitus is an exceptional congenital malformation consisting in the presence of two non-fused bony talar fragments. We report the case of an adolescent girl who complained of mechanical pain in the left ankle which became increasingly invalidating. Plain radiographs, CT-scan and MRI led to the diagnosis of this congenital anomaly: talus bipartitus. Surgical correction by subtalar arthrodesis provided improvement at the cost of reduced ankle mobility. Surgical treatment should be proposed for talus bipartitus in patients with invalidating pain or stiffness when rehabilitation fails to provide sufficient improvement.     

Gallbladder torsion. A case report

Gallbladder torsion is a rare condition causing acalculus cholecystitis. Its preoperative identification is difficult with current radiological means and it is generally diagnosed at surgery. A case of gallbladder torsion due to an extremely rare anomaly consisting of partial fixation of the fundus to a fore-shortened liver bed is reported. The etiology, diagnosis and treatment of this condition are discussed.     

Protective Effects of Volatile Agents against Methacholine-induced Bronchoconstriction in Rats

Background: The protective properties of common volatile agents against generalized lung constriction have previously been addressed only via estimations of parameters that combine airway and tissue mechanics. Their effectiveness in preventing airway constriction have not been compared systematically. Therefore, the authors investigated the abilities of halothane, isoflurane, sevoflurane, and desflurane to provide protection against airway constriction induced by methacholine.

Methods: Low-frequency pulmonary impedance data were collected in open-chest rats under baseline conditions and during three consecutive intravenous infusions of methacholine (32 [mu]g [middle dot] kg-1 [middle dot] min-1) while the animals were anesthetized with intravenous pentobarbital (control group). Methacholine challenges were performed in four other groups of rats, first during intravenous anesthesia and then repeated during the inhalation of halothane, isoflurane, sevoflurane, or desflurane at concentrations of 1 and 2 minimum alveolar concentration (MAC). Airway resistance and inertance, parenchymal damping, and elastance were estimated from the impedance data by model fitting.

Results: The methacholine-induced increases in airway resistance during intravenous pentobarbital anesthesia (204 +/- 53%) were markedly and significantly (P < 0.005) reduced by 1-MAC doses of halothane (80 +/- 48%), isoflurane (112 +/- 59%), sevoflurane (68 +/- 34%), and desflurane (96 +/- 34%), with no significant difference between the gases applied. Increasing the concentration to 2 MAC did not lead to any significant further protection against the increase in airway resistance.