Objective: To investigate, by transcranial magnetic stimulation, the effects of valproate on silent period and corticomotor excitability.
Methods: thirty patients with generalized epilepsy were studied at baseline, and re-examined 4 (S1) and 25 (S2) weeks after the administration of valproate (mean dose: 1040 +/- 284 mg). Transcranial magnetic stimulation was performed with a figure of eight coil (recording, first dorsal interosseous). Threshold was measured at 1% steps. Silent period was measured using a recently described protocol. Briefly, silent periods were elicited at 5% increments from 0 to 100% maximum stimulus intensity. At each stimulus intensity, 4 silent periods were obtained and the average value of silent period duration was used to construct a stimulus/response curve of stimulus intensity versus silent period. The resulting curves were then fitted to a Boltzman function and were statistically compared. The motor-evoked potential recruitment curve was constructed under active conditions and analyzed in a similar way.
Results: Valproate increased threshold from 36.5 +/- 5.99% at baseline to 41.02 +/- 7.84% at S1 (p < 0.0001, paired t-test). The maximum value of the silent period curve decreased from 257.5 +/- 3.9 ms at baseline to 230.3 +/- 3.9 ms at S1 (p < 0.0001, F-test and AIC) while the other best-fit values (V(50), slope, threshold) were not significantly affected. Regarding the motor-evoked potential recruitment curve, the maximum value decreased significantly post-drug (from 0.449 +/- 0.007 to 0.392 +/- 0.009, p < 0.01, F-test and AIC test), whereas the rest of the best-fit values remained unaffected.
Conclusion: In patients with idiopathic generalized epilepsy, valproate increases threshold and reduces the maximum values of the silent period curve and the motor-evoked potential recruitment curve. These findings probably reflect valproate's effects on voltage-dependent Na(+) channels, as well as an activation of GABA(A) receptors.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Postextubation Dysphagia Among Patients With COVID-19: Results of Instrumental Swallow Studies and Clinical Swallow Evaluations.
Am J Speech Lang Pathol
January 2025
Department of Therapy Services, University of Virginia Health System, Charlottesville.
Purpose: Research has shown that prolonged endotracheal intubation can increase risk of aspiration following extubation. This study examined the relationship between swallowing and intubation among patients with COVID-19. We investigated the association between the duration of intubation and time until an oral diet was safely initiated and the correlation between the length of intubation and reduced sensation with aspiration as seen on flexible endoscopic evaluation of swallowing (FEES)/videofluoroscopic swallowing study (VFSS).
View Article and Find Full Text PDFPrioritising gynaecological care in post-haematopoietic stem cell transplant patients.
BMJ Case Rep
January 2025
Reproductive Medicine and Surgery, Sri Ramachandra Medical College and Research Institute, Chennai, Tamil Nadu, India.
An adolescent girl with acute myeloid leukaemia underwent chemotherapy followed by haematopoietic stem cell transplantation (HSCT). Post-HSCT, she developed oral chronic graft-versus-host disease (cGvHD), which was successfully treated. Twenty months later, she was referred to the gynaecology department for evaluation of secondary amenorrhoea.
View Article and Find Full Text PDF[Berberine regulates glucose and lipid metabolism via clock-controlled genes to ameliorate insulin resistance of hepatocytes].
Zhongguo Zhong Yao Za Zhi
December 2024
Jiangxi Province Key Laboratory of Traditional Chinese Medicine Etiopathogenisis & Research Center for Differentiation and Development of Traditional Chinese Medicine Basic Theory, Jiangxi University of Chinese Medicine Nanchang 330004,China.
This study aims to investigate the mechanism of berberine in regulating the metabolism network via clock-controlled genes represented by brain and muscle arnt-like 1(BMAL1) to ameliorate insulin resistance(IR) of hepatocytes in vitro. The HepG2 cell model of dexamethasone-induced IR(IR-HepG2) was established and treated with 5, 10, and 20 μmol·L~(-1) berberine, respectively, for 24 h. The glucose oxidase method and cell counting kit-8(CCK-8) assay were employed to measure extracellular glucose concentration and cell viability, respectively.
View Article and Find Full Text PDFUltrafast multicellular calcium imaging of calcium spikes in mouse beta cells in tissue slices.
Acta Physiol (Oxf)
February 2025
Faculty of Medicine, University of Maribor, Maribor, Slovenia.
Background: The crucial steps in beta cell stimulus-secretion coupling upon stimulation with glucose are oscillatory changes in metabolism, membrane potential, intracellular calcium concentration, and exocytosis. The changes in membrane potential consist of bursts of spikes, with silent phases between them being dominated by membrane repolarization and absence of spikes. Assessing intra- and intercellular coupling at the multicellular level is possible with ever-increasing detail, but our current ability to simultaneously resolve spikes from many beta cells remains limited to double-impalement electrophysiological recordings.
View Article and Find Full Text PDFIt has been twenty-three years since China acceded to the WTO. Since then, China has participated in high-profile disputes through the WTO's DSM. During this period, China has evolved from being a silent observer to a sophisticated participant in the DSM.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!