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Objective: Epileptogenesis after status epilepticus (SE) has a faster onset in rats treated to reduce brain levels of the anticonvulsant neurosteroid allopregnanolone with the 5α-reductase inhibitor finasteride; however, it still has to be evaluated whether treatments aimed at increasing allopregnanolone levels could result in the opposite effect of delaying epileptogenesis. This possibility could be tested using the peripherally active inhibitor of 3β-hydroxysteroid dehydrogenase/Δ 5-4 isomerase trilostane, which has been shown repeatedly to increase allopregnanolone levels in the brain., Methods: Trilostane (50 mg/kg) was administered subcutaneously once daily for up to six consecutive days, starting 10 min after intraperitoneal administration of kainic acid (15 mg/kg). Seizures were evaluated by video-electrocorticographic recordings for 70 days maximum, and endogenous neurosteroid levels were assessed by liquid chromatography-electrospray tandem mass spectrometry. Immunohistochemical staining was performed to evaluate the presence of brain lesions., Results: Trilostane did not alter the latency of kainic acid-induced SE onset or its overall duration. When compared to the vehicle-treated group, rats receiving six daily trilostane injections presented a remarkable delay of the first spontaneous electrocorticographic seizure and subsequent tonic-clonic spontaneous recurrent seizures (SRSs). Conversely, rats treated with only the first trilostane injection during SE did not differ from vehicle-treated rats in developing the SRSs. Notably, trilostane did not modify neuronal cell densities or the overall damage in the hippocampus. In comparison to the vehicle group, repeated administration of trilostane significantly decreased the activated microglia morphology in the subiculum. As expected, allopregnanolone and other neurosteroid levels were remarkably increased in the hippocampus and neocortex of rats treated for 6 days with trilostane, but pregnanolone was barely detectable. Neurosteroids returned to basal levels after a week of trilostane washout., Significance: Overall, these results suggest that trilostane led to a remarkable increase in allopregnanolone brain levels, which was associated with protracted effects on epileptogenesis., (© 2023 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Background: Neurosteroids modulate epileptic activity by interacting with the γ-aminobutyric acid type A receptor, but their brain levels are still undetermined., Objectives: We aimed to establish neurosteroid levels in the neocortex and hippocampus by liquid chromatography/mass spectrometry in epileptic rats., Methods: Kainic acid-treated rats were continuously monitored up to 9 weeks to determine seizure frequency by video electrocorticography (n = 23) and compared to age-matched controls monitored in the same manner (n = 11)., Results: Decreased allopregnanolone (-50%; p < 0.05, Mann-Whitney test) and pregnanolone levels (-64%; p < 0.01) were found in the hippocampus, whereas pregnenolone sulfate, pregnenolone, progesterone, and 5α-dihydroprogesterone were nonsignificantly reduced. No changes were found in the neocortex. Moreover, allopregnanolone (but not pregnanolone) levels were positively correlated with seizure frequency (r2 = 0.4606, p < 0.01)., Conclusion: These findings indicate a selective reduction in hippocampal levels of 3α-reduced neurosteroids. This reduction was partially mitigated by seizures in the case of allopregnanolone., (© 2020 S. Karger AG, Basel.)

Neurosteroids can modulate γ-aminobutyric acid type A receptor-mediated inhibitory currents. Recently, we discovered that the neurosteroids progesterone, 5α-dihydroprogesterone, allopregnanolone, and pregnanolone are reduced in the cerebrospinal fluid of patients with status epilepticus (SE). However, it is undetermined whether neurosteroids influence SE. For this reason, first we evaluated whether the inhibitor of adrenocortical steroid production trilostane (50 mg/kg) could modify the levels of neurosteroids in the hippocampus and neocortex, and we found a remarkable increase in pregnenolone, progesterone, 5α-dihydroprogesterone, and allopregnanolone levels using liquid chromatography tandem mass spectrometry. Second, we characterized the dynamics of SE in the presence of the varied neurosteroidal milieu by a single intraperitoneal kainic acid (KA; 15 mg/kg) injection in trilostane-treated rats and their controls. Convulsions started in advance in the trilostane group, already appearing 90 minutes after the KA injection. In contrast to controls, convulsions prevalently developed as generalized seizures with loss of posture in the trilostane group. However, this effect was transient, and convulsions waned 2 hours before the control group. Moreover, electrocorticographic traces of convulsions were shorter in trilostane-treated rats, especially at the 180-minute (P < .001) and 210-minute (P < .01) time points. These findings indicate that endogenous neurosteroids remarkably modulate SE dynamics., (© 2020 International League Against Epilepsy.)

Background/aims: Status epilepticus (SE) might be followed by temporal lobe epilepsy (TLE), a common neurologic disorder characterized by spontaneous recurrent seizures (SRSs). However, the relationship between SE and TLE is still incompletely characterized. For this reason, in a model of TLE we evaluated the lesion extent and the onset of SRSs to determine if they were influenced by the SE dynamics., Methods: Sixty-two adult male Sprague-Dawley rats were implanted for video-electrocorticographic (v-ECoG) monitoring and intraperitoneally treated with saline or kainic acid (KA, 15 mg/kg) at 8 weeks of age. v-ECoG recordings were obtained during SE, in the following 9 weeks, and assessed by amplitude or power band spectrum. Rats were euthanized 3 or 64 days after SE to evaluate the lesion., Results: SE lasted about 10 h during which the mean duration of convulsive seizures (CSs) increased from 39 s, at 30 min, to 603 s at 4 h. The gamma power peaked 30 min after the SE onset and its peak was correlated (r²=0.13, p=0.042) with the overall SE duration. Subsequently, the gamma power was reduced under the baseline until the end of SE. The theta power increased at approximately 150% of basal levels 3 h after KA injection, but it went back to basal levels with the full development of CSs. Interestingly, the timing of the first SRS in chronic epilepsy was correlated with the latency to develop the first CS with loss of posture during SE (r²=0.60, p<0.001). Additionally, the overall duration of CSs observed during SE was related to the number of damaged brain regions (r²=0.60, p=0.005), but it did not influence the timing of the first SRS in chronic epilepsy., Conclusion: Overall, our results show that the onset of chronic epilepsy is modulated by SE dynamics, whereas brain damage is related to prolonged convulsions in SE., Competing Interests: The authors have no conflicts of interest to declare., (© Copyright by the Author(s). Published by Cell Physiol Biochem Press.)

Neurosteroids such as allopregnanolone may play a role in epilepsy as positive modulators of inhibitory currents mediated by γ-aminobutyric acid type A (GABA A ) receptor. Indeed, these molecules have been consistently shown to be anticonvulsants in animal models, but their role is still unclear in patients. For this reason, we investigated neurosteroids in the cerebrospinal fluid (CSF) of patients with status epilepticus (SE) by liquid chromatography tandem-mass spectrometry. Patients were retrospectively identified within subjects who received a lumbar puncture in the 2007-2017 period. Seventy-three patients (median age 65, ranging from 13 to 94 years; 67% women) with SE were evaluated. Controls (n = 52, median age 53, ranging from 16 to 93 years; 65% women) were patients presenting with symptoms for which a lumbar puncture was required by clinical guidelines, and who were negative at the end of the diagnostic work-up. Progesterone was 64% lower in patients with SE (p < 0.001). With respect to progesterone, upstream pregnenolone sulfate and pregnenolone did not change. Instead, downstream 5α-dihydroprogesterone, pregnanolone and allopregnanolone were, respectively, 49% (p < 0.001), 21% (p < 0.01) and 37% (p < 0.001) lower than in controls. Duration or type of SE, age and sex did not consistently affect CSF neurosteroid levels in the SE cohort. Instead, pregnenolone sulfate (Spearman's ρ = 0.4335, p < 0.01), allopregnanolone (ρ = 0.4121, p < 0.05) and pregnanolone (ρ = 0.592, p < 0.001) levels significantly increased by aging in controls. We conclude that neurosteroidogenesis is defective in patients with SE., (© 2018 International Society for Neurochemistry.)

Neuroactive steroids are increasingly considered as relevant modulators of neuronal activity. Especially allopregnanolone (AP) and pregnenolone sulfate (PS) have been shown to possess, respectively, anticonvulsant or proconvulsant properties. In view of the potential role of these steroids, we aimed at evaluating AP and PS levels in cerebrospinal fluid (CSF) and blood samples obtained from patients with status epilepticus (SE). To this purpose, we enrolled 41 patients affected by SE and 41 subjects investigated for nonepileptic neurologic disorders. Liquid chromatographic procedures coupled with electrospray tandem mass spectrometry and routine laboratory investigations were performed. Significantly lower AP levels were found in the CSF of patients affected by SE (-30%; p < 0.05, Mann-Whitney test). Notably, AP was not detectable in 28 of 41 patients affected by SE (p < 0.01 vs. controls, Fisher's exact test). In serum, AP levels did not differ in the two considered groups. Conversely, PS was present at similar levels in the investigated groups. Finally, differences in AP levels could not be explained by a variation in CSF albumin content. These findings indicate that AP is defective in the CSF of patients affected by SE. This phenomenon was not dependent on carriers for steroids, such as albumin., (Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.)

Status epilepticus (SE) is one of the recognized primary precipitating events that can lead to temporal lobe epilepsy (TLE) associated with hippocampal sclerosis. This type of epilepsy is characterized by poor response to drug treatment, often requiring surgical intervention to remove the mesial temporal regions involved in the seizure onset. However, even neurosurgery may not be completely successful. Thus, the prevention of hippocampal damage and epileptogenesis is currently evaluated as a possible alternative therapeutic approach to prevent the development of pharmacoresistant TLE. Lines of evidence suggest that ischemic-hypoxic lesions might occur in different brain regions, including the hippocampus, during SE. Especially in the hippocampal CA3 region, an ischemic-like lesion develops in the stratum lacunosum-moleculare and is mainly characterized by a loss of astrocytes and neuronal processes and increased immunostaining of pimonidazole which probes areas exposed to hypoxia. Interestingly, these mechanisms can contribute to neuronal cell loss and may be counteracted by drugs that can afford vascular protection, as in the case of ligands of the ghrelin receptor. Notably, some of the ghrelin receptor ligands possess a double edge effect, since they are anticonvulsant and vascular-protective, thus, potentially representing new tools to counteract the consequences of SE. This article is part of a Special Issue entitled "Status Epilepticus"., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In models of status epilepticus ghrelin displays neuroprotective effects mediated by the growth hormone secretagogue-receptor 1a (GHS-R1a). This activity may be explained by anticonvulsant properties that, however, are controversial. We further investigated neuroprotection and the effects on seizures by comparing ghrelin with a more effective GHS-R1a agonist, JMV-1843. Rats were treated either with ghrelin, JMV-1843 or saline 10 min before pilocarpine, which was used to induce status epilepticus. Status epilepticus, developed in all rats, was attenuated by diazepam. No differences were observed among the various groups in the characteristics of pilocarpine-induced seizures. In saline group the area of lesion, characterized by lack of glial fibrillary acidic protein immunoreactivity, was of 0.45 ± 0.07 mm(2) in the hippocampal stratum lacunosum-moleculare, and was accompanied by upregulation of laminin immunostaining, and by increased endothelin-1 expression. Both ghrelin (P<0.05) and JMV-1843 (P<0.01) were able to reduce the area of loss in glial fibrillary acidic protein immunostaining. In addition, JMV-1843 counteracted (P<0.05) the changes in laminin and endothelin-1 expression, both increased in ghrelin-treated rats. JMV-1843 was able to ameliorate neuronal survival in the hilus of dentate gyrus and medial entorhinal cortex layer III (P<0.05 vs saline and ghrelin groups). These results demonstrate diverse protective effects of growth hormone secretagogues in rats exposed to status epilepticus.