The use of exogenous electrical stimulation to promote nerve regeneration has achieved only limited success. Conditions impeding optimized outgrowth may arise from inadequate stimulus presentation due to differences in injury geometry or signal attenuation. Implantation of an electrically-conductive biomaterial may mitigate this attenuation and provide a more reproducible signal. In this study, a conductive nanofiller (single-walled carbon nanotubes [SWCNT]) was selected as one possible material to manipulate the bulk electrical properties of a collagen type I-10% Matrigel™ composite hydrogel. Neurite outgrowth within hydrogels (SWCNT or nanofiller-free controls) was characterized to determine if: 1) nanofillers influence neurite extension and 2) electrical stimulation of the nanofiller composite hydrogel enhances neurite outgrowth. Increased SWCNT loading (10–100-μg/ml) resulted in greater bulk conductivity (up to 1.7-fold) with no significant changes to elastic modulus. Neurite outgrowth increased 3.3-fold in 20-μg/mL SWCNT loaded biomaterials relative to the nanofiller-free control. Electrical stimulation promoted greater outgrowth (2.9-fold) within SWCNT-free control. The concurrent presentation of electrical stimulation and SWCNT-loaded biomaterials resulted in a 7.0-fold increase in outgrowth relative to the unstimulated, nanofiller-free controls. Local glia residing within the DRG likely contribute, in part, to the observed increases in outgrowth; but it is unknown which specific nanofiller properties influence neurite extension. Characterization of neuronal behavior in model systems, such as those described here, will aid the rational development of biomaterials as well as the appropriate delivery of electrical stimuli to support nerve repair.

Summary:Purpose: To determine both the efficacy of and compliance with the ketogenic diet in the adolescent population.Methods: A retrospective study of 45 patients, aged 12-19 years, consecutively enrolled in a ketogenic diet program from 1994 to 2002, was performed. Thirty-seven patients were from The Johns Hopkins Medical Institutions; eight were from The University of Texas at Houston. Charts were reviewed, and patients were contacted by telephone.Results: Six months after diet initiation, 28 (62%) of 45 remained on the ketogenic diet, with six (21%) of 28 having 50-90% seizure reduction, and eight (29%) of 28 having >90%. At 12 months, 20 (44%) of 45 remained on the diet, with seven (35%) of 20 having 50-90% seizure reduction and six (30%) of 20 achieving >90% efficacy. Only 22% discontinued the diet for perceived restrictiveness. The mean diet duration was 1.2 years. Patients with multiple seizure types did best, whereas gender, prior seizure frequency, diet ratio, and age did not influence outcome. Patients dependent on parents for daily care were more likely to remain on the diet at 6 months, but had less efficacy. Weight loss (60%) and menstrual dysfunction (45% of female subjects) were the most commonly reported side effects.Conclusions: The ketogenic diet is as well tolerated and efficacious for adolescents with epilepsy as for the general childhood population.

Intravenous antiepileptic drugs are required in patients needing urgent treatment or unable to take oral medication. The safety of intravenous levetiracetam has been established in prospective studies of adult epilepsy and healthy participants. The authors performed a prospective, single-center study to evaluate the safety of a rapid loading dose of intravenous levetiracetam. Patients were divided into 3 equal dosing groups (N = 15 each): 20, 40, and 60 mg/kg (corresponding to maximum doses of 1, 2, and 3 g). Electrocardiogram and safety assessment were performed during the infusion. Ages were 4 to 32 years. Postinfusion serum levetiracetam concentrations were 14 to 189 microg/mL. There were no significant changes in blood pressure, no local infusion site reactions, and no electrocardiogram abnormalities. The authors concluded that high serum levels of parenteral levetiracetam can be achieved rapidly and safely, in a small infusion volume. This finding has important implications for the treatment of status epilepticus.

No abstract

There is an increased probability of a partial or total displacement of key components of the brain mechanism responsible for receptive language function to the nondominant hemisphere in mesial temporal sclerosis patients. Early onset of seizures is strongly associated with atypical language lateralization. Lesions in the dominant hemisphere tend to result in an intrahemispheric reorganization of linguistic function.