Incidence Of Tonic-clonic Seizures Research Articles

Acute and chronic cardiorespiratory consequences of focal intrahippocampal administration of seizure-inducing agents. Implications for SUDEP

<h2>Abstract</h2> The risk factors for SUDEP are undoubtedly heterogenous but the main factor is the frequency of generalized tonic-clonic seizures with apnoea and/or cardiac abnormalities likely precipitating the lethal event. By its very nature modelling SUDEP experimentally is challenging, yet insights into the nature of the lethal event and precipitating factors are vital in order to understand and prevent fatalities. Acute animal models, which induce status epilepticus (SE), can be used to help understand pathophysiological processes during and following seizures, which sometimes lead to death. The most commonly used method to induce seizures and status epilepticus is systemic administration of an ictogenic agent. Microinjection of such agents into restricted regions within the brain induces a more localised epileptic focus and circumvents the risk of direct actions on cardiorespiratory control centres. Both approaches have revealed substantial cardiovascular and respiratory consequences, including death as a result of apnoea, which may be of central origin, obstructive due to laryngospasm or, at least in genetically modified mice, a result of spreading depolarisation to medullary respiratory control centres. SUDEP is by definition a result of epilepsy, which in turn is diagnosed on the basis of two or more unprovoked seizures. The incidence of tonic-clonic seizures is the main risk factor, raising the possibility that repeated seizures cause cumulative pathological and/or pathophysiological changes that contribute to the risk of SUDEP. Chronic experimental models, which induce repeated seizures that in some cases lead to death, do show progressive development of pathophysiological changes in the myocardium, e.g. prolongation of QT the interval of the ECG or, over longer periods, ventricular hypertrophy. However, the currently available evidence indicates that seizure-related deaths are primarily due to apnoeas, but cardiac factors, particularly cumulative cardiac pathophysiologies due to repeated seizures, are potential contributing factors.

Seizure frequency and obstetric complications at advanced maternal age: a preliminary observational study in women with epilepsy

BackgroundSeizure control during pregnancy and obstetric outcomes are of important concerns for women with epilepsy (WWE) and their families. Advanced maternal age (≥35 years) shows a growing trend in the society with changes of lifestyle, which also occurs in diseased populations. The advanced maternal age is an independent factor for some unsatisfying obstetric outcomes. In this study we explored the seizure control and obstetric complications associated with advanced maternal age in WWE.MethodsThis study was based on the epilepsy pregnancy registry at West China Hospital. Patients with epilepsy in this registry who were aged 35 or older when starting pregnancy were included in this study. Their basic demographics and detailed information on epilepsy management and obstetric issues in all trimesters and during 1-year follow-up after birth were documented and reviewed. Data were processed by IBM SPSS version 22.0. The demographic characteristics, seizure frequency, treatment change, obstetric complications, and outcomes were analyzed and compared.ResultsFifteen patients were included in this study, with an average age of 36.32 ± 2.39 years at pregnancy, and 73.33% of them were primiparas. The change of seizure frequency during pregnancy was not in a clear pattern, but there was an increased incidence of tonic-clonic seizures during the mid- and last trimesters. More than 20% of the patients had obstetric complications throughout the trimesters, including vaginal bleeding, hypothyroidism, and pre-eclampsia. The pre-eclampsia seemed extraordinarily complicated with other conditions. However, none of the complications were related with malformations or poor outcome of babies after 1-year follow-up.ConclusionAdvanced maternal age combined with WWE is associated with frequent common obstetric complications. Future controlled studies with large sample sizes are needed to explore the related risks in comparison with other WWE and non-epileptic populations.

Testosterone reduces pentylenetetrazole-induced ictal activity of wildtype mice but not those deficient in type I 5α-reductase

Testosterone’s (T) anti-seizure effects may be mediated in part by actions of its 5α-reduced metabolites. To test this hypothesis, T was administered to knockout mice deficient in the 5α-reductase type I enzyme and wildtype controls and their ictal activity following pentylenetetrazole (PTZ; 85 mg/kg i.p.) was compared to mice administered vehicle. T to wildtype mice increased latencies to forelimb clonus, tonic clonic seizures, hindlimb extension, and death compared to that seen with vehicle administration. Moreover, incidence of tonic clonic seizures and hindlimb extension were reduced in wildtype mice administered T compared to vehicle-administered mice. T administration to wildtype mice reduced ictal activity compared to T to knockout mice, which were not different than vehicle-administered control mice. T to wildtype mice increased the latencies and decreased the incidence of forelimb clonus compared to T to knockout mice, which were not different from vehicle-administered mice. These data are consistent with T having anti-convulsant effects and that 5α-reduced metabolites may mitigate some of T’s anti-seizure effects.