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Bone mineral metabolism changes in epileptic children receiving valproic acid.
Oner, N, Kaya, M, Karasalihoğlu, S, Karaca, H, Celtik, C, Tütüncüler, F
Journal of paediatrics and child health. 2004;(8):470-3
Abstract
OBJECTIVE The aim of this study was to evaluate bone mineral density (BMD) in epileptic children receiving valproic acid (VPA) and to determine differences between osteopenic and non-osteopenic children. METHODS Thirty-three epileptic children, receiving VPA for at least 6 months, were compared with 33 healthy children for BMD. BMD was measured by dual-energy X-ray absorptiometry at lumbar vertebrae, femoral neck and greater trochanter. Serum calcium, phosphorus, alkaline phosphates, osteocalcin and VPA levels were also determined. RESULTS Patient's osteocalcin levels were significantly higher (P = 0.02) and femur and trochanter BMD values were significantly lower (P = 0.04 and P = 0.03, respectively). Duration of VPA therapy was significantly longer and doses of VPA were significantly higher in seven osteopenic patients compared with 26 non-osteopenic patients. Osteopenic patients (4.6 +/- 2.4 years) were younger than non-osteopenic patients (7.8 +/- 3.2 years) (P = 0.01). CONCLUSION Long-term and high dose VPA therapy may cause osteopenia, primarily in younger epileptic children. These patients should be followed closely by BMD measurements.
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Neural bases of cognitive ERPs: more than phase reset.
Fell, J, Dietl, T, Grunwald, T, Kurthen, M, Klaver, P, Trautner, P, Schaller, C, Elger, CE, Fernández, G
Journal of cognitive neuroscience. 2004;(9):1595-604
Abstract
Up to now, two conflicting theories have tried to explain the genesis of averaged event-related potentials (ERPs): Whereas one hypothesis claims that ERPs originate from an event-related activation of neural assemblies distinct from background dynamics, the other hypothesis states that ERPs are produced by phase resetting of ongoing oscillatory activity. So far, this question has only been addressed for early ERP components. Late ERP components, however, are generally thought to represent superimposed activities of several anatomically distinct brain areas. Thus, the question of which mechanism underlies the genesis of late ERP components cannot be easily answered based on scalp recordings. In contrast, two well-investigated late ERP components recorded invasively from within the human medial temporal lobe (MTL) in epilepsy patients, the so-called MTL-P300 and the anterior MTL-N400 (AMTL-N400), are based on single source activity. Hence, we investigated whether the MTL-P300 and the AMTL-N400 are based on an event-related activity increase, a phase reset of ongoing oscillatory activity or both. ERPs were recorded from the hippocampus and rhinal cortex in subjects performing a visual oddball paradigm and a visual word recognition paradigm. With wavelet techniques, stimulus-related phase-locking and power changes were analyzed in a frequency range covering 2 to 48 Hz. We found that the MTL-P300 is accompanied by both phase reset and power increase and that both effects overlap partly in time. In contrast, the AMTL-N400 is initially associated with phase locking without power increase and only later during the course of the AMTL-N400 we observed an additional power increase. In conclusion, both aspects, event-related activation of neural assemblies and phase resetting of ongoing activity seem to be involved in the generation of late ERP components as recorded in cognitive tasks. Therefore, separate analysis of event-related power and phase-locking changes might reveal specific insights into the mechanisms underlying different cognitive functions.
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Antioxidant and anticonvulsant effect of a modified formula of chaihu-longu-muli-tang.
Hung-Ming, W, Liu, CS, Tsai, JJ, Ko, LY, Wei, YH
The American journal of Chinese medicine. 2002;(2-3):339-46
Abstract
Antiepileptic drug therapy in individuals with epilepsy can induce free radical generation and profound lipid peroxidation. Some Chinese herbs with antiepileptic potential show antioxidant effects. We performed an open add-on study of TW970, a modified formula of the Chinese medicine "chaihu-longu-muli-tang", on 20 patients with refractory epilepsy and a seizure frequency of at least four fits per month, and another 20 patients with benign epilepsy and a seizure frequency of less than four fits per month. The control group consisted of 20 age-matched healthy adults. Seizure frequency, serum malondialdehyde (MDA), glutathione (GSH) and copper-zinc superoxide dismutase (Cu,Zn-SOD) were investigated in patients with refractory and benign epilepsy before and after four months add-on treatment of TW970. There was a decrease in seizure frequency in refractory epileptics from 13.4 +/- 3.4 to 10.7 +/- 2.5/per month, although the p value was 0.084. Before TW970 add-on treatment, a significant enhancement of lipid peroxidation with increased MDA and Cu,Zn-SOD activities together with decreased GSH were seen in refractory epileptics compared with normal controls. After TW970 add-on treatment of refractory epileptics for four months, normalization of MDA and Cu,Zn-SOD levels was achieved. Before and after TW970 add-on treatment, there were no statistically significant changes of the above-mentioned parameters in the patients with benign epilepsy. These results suggest that TW970 can reduce the seizure frequency in patients with refractory epilepsy and this may be due to the antioxidant effects of the modified formula of chaihu-longu-muli-tang.
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The effect of B-vitamins on hyperhomocysteinemia in patients on antiepileptic drugs.
Apeland, T, Mansoor, MA, Pentieva, K, McNulty, H, Seljeflot, I, Strandjord, RE
Epilepsy research. 2002;(3):237-47
Abstract
Patients on antiepileptic drugs (AEDs) may have elevated levels of plasma total homocysteine (p-tHcy). The aim of this study was to assess the effect of B-vitamin supplementation on the levels of p-tHcy and markers of endothelial activation and lipid peroxidation. A total of 33 adult patients on AEDs were identified with either fasting (Group 1, n=23) or post methionine load (PML) (Group 2, n=10) hyperhomocysteinemia. Subjects were supplemented with B-vitamins for 30 days: folic acid 0.4 mg, pyridoxine 120 mg and riboflavin 75 mg per day. After supplementation, serum folate and pyridoxal phosphate had increased, while fasting and PML p-tHcy had decreased (P<0.0001) by 36 and 26%, respectively. Prior to supplementation, the Group 1 patients had elevated levels of P-selectin and von Willebrand factor (vWF) (P=0.05 and 0.03, respectively). After supplementation, the levels of intercellular cell adhesion molecules had decreased (P=0.01) and E-selectin decreased nonsignificantly (P=0.07). However, the levels of vascular cell adhesion molecules had increased (P<0.0001), while lipid peroxidation were unchanged. In conclusion, the combined supplementation with folic acid, pyridoxine and riboflavin reduced fasting and PML hyperhomocysteinemia in patients on AEDs. Patients with fasting hyperhomocysteinemia had elevated levels of P-selectin and vWF, which may indicate an increased risk of cardiovascular disease. Furthermore, B-vitamin supplementation influenced endothelial activation, although the clinical implication is uncertain.