Nonepileptic seizures during apparent sleep

We report 12 patients with nonepileptic seizures(NESs) documented with video-electroencephalographic monitoring during apparent sleep. There were 7 females and 5 males, ages 11 to 67 years(mean, 33 yr). In all patients there was a well-organized posterior α rhythm present immediately before onset of clinical changes despite the appearance of sleep. Patients later “confirmed” that these attacks occured during sleep. Features of these episodes were typical of NESs and none were associated with ictal or postictal electroencephalographic changes other than muscle and movement artifact. Provocative testing with suggestion confirmed the nonepileptic nature of these episodes in 9 patients. Three patients had epileptiform discharges during prolonged interictal recordings and 1 had a documented complex partial seizure. Our findings indicate that reports of seizures during sleep are not uncommon among patients with NESs.     

Tests of two new polyurethane foam wheelchair tires

The performance characteristics of four 24-inch wheelchair tires are considered; one pneumatic and three airless. Specifically, two new airless polyurethane foam tires (circular and tapered cross-section) were compared to both a molded polyisoprene tire and a rubber pneumatic tire. Rolling resistance, coefficient of static friction, spring rate, tire roll-off, impact absorption, wear resistance, and resistance to compression set were the characteristics considered for the basis of comparison. Although the pneumatic tire is preferred by many wheelchair users, the two new polyurethane foam tires were found to offer a performance similar to the high-pressure pneumatic tire. In addition, the foam tires are less expensive and lighter in weight than the other tires tested.     

Corpus callosum and limbic system: neuroanatomic MR evaluation of developmental anomalies

Agenesis of the corpus callosum is a complex malformation of the brain that has been associated with varying degrees of limbic system maldevelopment. We retrospectively reviewed the records of 11 patients with callosal agenesis (seven total, four partial) who underwent magnetic resonance (MR) imaging, with particular attention to the associated malformations of the limbic system. Comparison was made with selected images from MR examinations of healthy volunteers and with necropsy specimens from other patients with callosal agenesis. Ten of 11 patients demonstrated limbic anomalies (severe motion artifact precluded evaluation of these structures in one patient). MR depicted not only the abnormalities intrinsic to callosal agenesis but also the frequently associated malformations of the limbic system.     

Robust quantification of short echo time 1H magnetic resonance spectra using the Padé approximant

Accurate quantification of in vivo short echo time spectra is hampered by the presence of overlapping peaks and a significant baseline. In this work the Padé approximant in conjunction with Monte Carlo simulation is used to extract peak areas from short echo time ¹H spectra. We exploit the fact that the Padé approximant is known to model broad non‐Lorentzian signals as arbitrary sums of Lorentzian components to separate baseline components from sharper metabolite signals by combining the Padé approximant with Monte Carlo simulation. The simulation results demonstrate that the Padé approximant–Monte Carlo hybrid analysis is able to separate the metabolite signals from the baseline, while a least squares fitting of a time domain model may result in significant bias of the peak area estimations. For the in vivo data the estimates of the peak areas using the Padé approximant and AMARES compare well, with the exception of the NAA peak at 2.02 ppm. We suggest that the discrepancy may be due to the baseline contamination as supported by the simulation results; however, without an in vivo gold standard this remains difficult to demonstrate. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.     

Pulmonary arteriovenous malformations: techniques and long-term outcome of embolotherapy

Over a 10-year period, 276 pulmonary arteriovenous malformations (PAVMs) were occluded with balloon embolotherapy in 76 patients, 67 (88%) of whom had hereditary hemorrhagic telangiectasia. Eleven patients (14%) were discovered by means of family screening with measurement of arterial blood gases and chest radiography. Epistaxis, dyspnea, hemoptysis, and hemothorax occurred in 79%, 71%, 13%, and 9% of patients, respectively. Clinical histories of strokes and transient ischemic attacks were present in 18% and 37% of patients, respectively. Computed tomographic scans of 59 patients showed stroke in 36%. Sixty-five percent of PAVMs were located in the lower lobes, which correlated with the finding of more pronounced hypoxemia in the upright position. After embolotherapy, symptomatic hypoxemia was corrected, and serial values have remained constant for 5 years. Complications were minimal, and no patient required surgery. Balloon embolotherapy is effective long-term therapy for PAVMs, and family screening should be pursued because of the possibility of a higher frequency of paradoxical embolization (stroke) than previously recognized.     

Scientific basis for selecting surgical needles and needle holders for wound closure

Standardized reproducible tests have been devised to determine surgical needle sharpness, resistance to bending, and ductility. Three comparable groups of reverse cutting edge needles were selected from different manufacturers for measurement of these needle performance parameters. This testing demonstrated that needle diameter, manufacturing process, needle material composition, cross-sectional design, and the manufacturer were all important determinants of surgical needle performance. In addition, the biomechanics of curved surgical needle bending has been related to the clamping moment of surgical needle holders. This relationship identifies the surgical needle holder that can be used with surgical needles without deformation. The results of these studies provide a scientific basis for the selection of surgical needles and needle holders for use in surgery.     

Sustained Bronchodilation with Isoproterenol Poly(Glycolide-co-Lactide) Microspheres

An animal study was carried out to evaluate the in vivo bronchodilator action of isoproterenol (Iso) from poly(glycolide-co-lactide) (PGL) microspheres. Microspheres with a mean diameter of 4.5 µm and a drug load of 7% were administered intratracheally to Long-Evans rats. The microspheres released about 70% of the incorporated drug in the instillation medium before administration, which provided immediate action, and the remaining 30% was available for sustained release. A total of 120 animals was anesthetized, paralyzed, artificially ventilated, and divided into 15 groups (n = 8): 3 groups each for saline, blank microspheres, free Iso, blank microspheres with free Iso, and microencapsulated Iso. All instillations were made in a volume of 1 ml/kg and the dose of all Iso preparations was 0.1 mg/kg. At 3, 6, or 12 hr after the intratracheal instillation, a serotonin challenge (40 µg/rat) was administered intravenously to constrict the airways. Airway function tests were performed at each time interval on one group of animals by a maximal expiratory flow-volume maneuver. The heart rate in animals receiving Iso formulations was similar to that in the saline control group, indicating minimal systemic effect of the dose administered. The systemic serum levels were below 2 ng/ml in all the groups. Animals receiving encapsulated Iso resisted the serotonin challenge for at least 12 hr after intratracheal instillation, indicating that the drug was still present over this period of time. On the other hand, the serotonin-induced airway constriction observed in the animals receiving blank microspheres, free Iso, or free Iso with blank microspheres was similar to that in saline controls at all time points. The results clearly show that only a small fraction of the free dose is required in sustained-release form for a prolonged pharmacological effect, resulting in a 50- to 100-fold reduction in the total dose administered.