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Numerical Results and Biological Conclusions
Published in Candace M. Kent, David M. Chan, Analysis of a Model for Epilepsy, 2022
Candace M. Kent, David M. Chan
We investigate the relationship between the degree of hyperexcitability of neurons involved in seizures (see Definition 2.4) with (1) the variability in seizures at low seizure thresholds, and (2) the partial or complete elimination of seizures at high seizure thresholds. Based on findings from the model concerning the bifurcation values b0 and b1 for Cases 1–8 below, we show that possibly the greater the degree is to which the neurons involved in seizures potentially become hyperexcitable in mesial temporal lobe epilepsy the greater is and thus the greater the interval of seizure thresholds at the low end of the spectrum (i.e., ) is over which the model shows high variability in seizure characteristics such as duration, frequency, and severity as discussed in Subsection 5.2; andthe greater the minimum seizure threshold, , is at which there is attainment of a partially or completely seizure-free state.
Neurologic disorders in pregnancy
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Robert Burger, Terry Rolan, David Lardizabal, Upinder Dhand, Aarti Sarwal, Pradeep Sahota
Epilepsy per se does not pose a teratogenic risk. Most WWE have no change in seizure frequency during pregnancy or even develop fewer seizures. Only 15% to 33% have more seizures during pregnancy (51,66–68). AED pharmacokinetics is altered during pregnancy. Serum drug concentrations are reduced by increasing maternal blood volume, a phenomenon that reaches its nadir at term (69,70). However, seizure frequency increases as early as the first trimester and not necessarily around term, so reduced AED levels only partially explain the phenomenon. Hormonal changes may also contribute: the ratio of estrogen (which lowers seizure threshold) to progesterone (which raises seizure threshold) increases during pregnancy reaching its peak between weeks 8 and 16. Other factors that may contribute to a lower seizure threshold include stress, anxiety, and sleep deprivation. Also some women stop therapy because of the fear of teratogenic effects. Generalized tonic clonic seizure during pregnancy can result in fetal intracranial hemorrhage, transient fetal brady-cardia, heart beat variability, fetal hypoxia, and stillbirth. Status epilepticus resulted in 30% maternal mortality and 50% infant mortality. There is no evidence that non-convulsive seizures during pregnancy adversely affect outcome apart from trauma.
Prescribing for a first episode of schizophrenia-like psychosis
Published in Kathy J Aitchison, Karena Meehan, Robin M Murray, First Episode Psychosis, 2021
Kathy J Aitchison, Karena Meehan, Robin M Murray
Antipsychotic medications, particularly the low-potency typical antipsychotics and clozapine, can lower the seizure threshold. The frequency of seizures is dose related; the rates are less than 1% for all typicals at standard doses. Risk factors for medication-induced seizures include: idiopathic epilepsyhead injuryfamily history of epilepsyhistory of previous medication-induced seizurehigh rate of increase of dose
Managing pregnancy in women with Sturge-Weber syndrome: case report and review of the literature
Published in Journal of Obstetrics and Gynaecology, 2022
Vignesh Durai, Haritha Sagili, Jayalakshmi Durairaj, Ramesh Ananthakrishnan, Pradeep P. Nair, Arun Keepanasseril, Anish Keepanasseril
Hormonal changes, the increase in stress and reduction in sleep during pregnancy may cause lowering of the seizure threshold, can predispose to recurrence or exacerbation of seizures in pregnancy (Dolkart and Bhat 1995). Recurrence of seizures should be differentiated from those following intracranial haemorrhage from rupture of angiomas and the pregnancy-specific causes such as eclampsia, which necessitates an urgent evaluation with neuro-imaging to aid early diagnosis and intervention. Only two of the 11 cases reported in women with SWS were seizure-free during pregnancy (Table 2). Most of them needed anti-seizure agents to prevent seizure recurrence, except one who underwent hemispherectomy for refractory seizures during infancy, following which she remained seizure-free (Aziz et al. 2013). Monotherapy and minimum possible maintenance doses, similar to the pregnant women with epilepsy, of the anti-seizure agents to avoid recurrence of seizures and reduce their effect on the baby should be continued throughout pregnancy (Borgelt et al. 2016).
A comparison of the safety, feasibility, and tolerability of ECT and ketamine for treatment-resistant depression
Published in Expert Opinion on Drug Safety, 2022
Amanda Tamman, Amit Anand, Sanjay J. Mathew
Though ECT appears to be a safe and low-risk procedure in adolescents, ECT has been associated with broadly distributed volumetric gray matter increases in the brain that do not predict clinical response [69]. Such neural changes raise concerns for vulnerable developing brain. Side effect profile considerations specific to this group should be made. These considerations include greater risk of prolonged seizures and of tardive seizures following ECT treatment [64] in 5% and 10% of adolescents, respectively, compared to just 1.1% of adults [70,71]. This increased likelihood is thought to reflect a lower seizure threshold in children and adolescents compared to middle age or older adults [72]. Consequently, AACAP recommends increased monitoring pediatric populations for at least 24 hours after ECT [64,73,74]. AACAP advises each patient should be evaluated by a second physician who is knowledgeable about ECT for a second opinion [64]. Other considerations include administering a comprehensive pre-treatment evaluation for children and adolescents, including regular cognitive assessments and baseline neuropsychological assessments.
Dosing methods in electroconvulsive therapy (ECT): towards the modal ECT technique
Published in Nordic Journal of Psychiatry, 2022
Charles H. Kellner, Martin B. Jørgensen
As part of their plea to bring back the Scandinavian time-titration method, Bergsholm and Bjølseth consider whether individualized stimulus dose titration is necessary and helpful. They discuss some recent literature on this topic and quote several skeptical authors, one of us (CHK), included. A central question relevant to this is whether or not there is great variability in seizure threshold (ST). We would suggest, that while a few outliers exist, the vast majority of patients have highly predictable STs. This view is supported by several large datasets [2,3] and the fact that age- and formula-based dosing methods work for the vast majority of patients. If a patient has an unusually high ST, this will be discovered at the first treatment session, and appropriate steps can be taken to ensure effective treatments at subsequent sessions. If ST outliers comprise 1-10% of ECT patients, the technique should be geared to the 90%, not the 10%. In addition, the concept that there exists an optimal charge dose that is a multiple of ST has never been adequately replicated. In summary, while the promise of ‘personalized’ or ‘individualized’ medicine is tempting, there is no solid evidence that dose titration leads to better ECT outcomes.