The Effects and Mechanisms of Action of TC-G 1008, GPR39 Agonist, in Animal Models of Seizures and Epilepsy

Background and purpose: The G-protein coupled receptor 39 (GPR39) may be activated by zinc ions. Activation of GPR39 was suggested as a novel pharmacological strategy for treating seizures. Experimental approach: We utilized a specific agonist of GPR39, TC-G 1008, and the nonspecific agonist, zinc chloride and a variety of models of acute seizures or a chronic model of epilepsy which were induced in non-genetically modified mice, GPR39 knockout mice or in zebrafish larvae. We examined total serum zinc (by Inductively Coupled Plasma Optical Emission Spectrometry) as well as intracellular zinc ([Zn2+]I) (by Zinpyr-1 staining) concentrations and the expression of selected proteins (by Western blot) which are associated with GPR39 signaling in the hippocampus. Key results: Liquid chromatography tandem mass spectrometry analysis showed that TC-G 1008 is brain penetrant. TC-G 1008 decreased the seizure threshold in the maximal electroshock seizure (MES) threshold test, but it increased the seizure threshold in the 6-Hz induced seizure threshold test. The behavioral effects of TC-G 1008 and MES or 6-Hz seizure were accompanied by alterations in hippocampal [Zn2+]I. TC-G 1008 increased the mean duration of EEG discharges in response to pentylenetetrazole (PTZ) in zebrafish larvae and facilitated the development of PTZ kindling in mice. Using GPR39 knockout mouse line, generated by the CRISPR-Cas-9 method, we showed that GPR39 is a target for TC-G 1008 regarding PTZ-induced epileptogenesis. Conclusion and implications: Our in vivo data obtained using TC-G 1008 generally argue against GPR39 activation as a therapeutic strategy for alleviating seizures/epilepsy.

Scorpion Envenomation of Lactating Rats Decreases the Seizure Threshold in Offspring

Few data are available in the literature describing the long-term effects of envenoming in the perinatal period. In this study, the relationship between envenoming of lactating rats and possible behavioral changes in the mother and in her offspring were investigated. Lactating Wistar rats received a single dose of T. serrulatus crude venom on postnatal days 2 (V2), 10 (V10) or 16 (V16), and had their maternal behavior evaluated. The seizure threshold was evaluated in adulthood offspring. A decrease in maternal care during envenoming was observed in V2 and V10 groups. The retrieval behavior was absent in the V2 group, and a lower seizure threshold in the adult offspring of all groups was observed. During envenoming, mothers stayed away from their offspring for a relatively long time. Maternal deprivation during the early postnatal period is one of the most potent stressors for pups and could be responsible, at least in part, for the decrease in the convulsive threshold of the offspring since stress is pointed to as a risk factor for epileptogenesis. Furthermore, the scorpionic accident generates an intense immune response, and inflammation in neonates increases the susceptibility to seizures in adulthood. Therefore, maternal envenoming during lactation can have adverse effects on offspring in adulthood.

New Onset Focal Seizure Following COVID-19 Vaccination: Case Report

IntroductionAs more novel COVID-19 vaccines are being rolled out in a frantic pace globally, any complication that might be related to COVID-19 vaccines should be highlighted, especially since COVID-19 vaccines are relatively new, and side effects may yet to be fully elucidated. We report a case of a healthy 18-year-old male who presented with new onset focal seizures 5 days after receiving 1st dose of Oxford/AstraZeneca COVID-19 vaccine. Case PresentationThe patient was treated with intravenous phenytoin and oral levetiracetam 250mg twice daily with no further events. There was no documented fever. CT venogram and EEG were unremarkable. MRI brain revealed generalised atrophy including mild bilateral hippocampal atrophy with no evidence of sclerosis. There was no predilection for seizures identified from the patient’s history. The patient was discharged the following day on levetiracetam and advised to proceed with the 2nd dose of Oxford/AstraZeneca COVID-19 vaccination in 3 months’ time.ConclusionSeizures following COVID-19 vaccination have only been reported in a handful of cases. COVID-19 vaccination could lower seizure threshold, or unmask an underlying predisposition for epilepsy. As most COVID-19 vaccines worldwide are given in 2 doses, clinicians should consider maintaining patients on anti-seizure drugs if vaccination was thought to be a provoking factor.

Propofol and Sevoflurane Anesthesia in Early Childhood Do Not Influence Seizure Threshold in Adult Rats

Experimental studies have demonstrated that general anesthetics administered during the period of synaptogenesis may induce widespread neurodegeneration, which results in permanent cognitive and behavioral deficits. What remains to be elucidated is the extent of the potential influence of the commonly used hypnotics on comorbidities including epilepsy, which may have resulted from increased neurodegeneration during synaptogenesis. This study aimed to test the hypothesis that neuropathological changes induced by anesthetics during synaptogenesis may lead to changes in the seizure threshold during adulthood. Wistar rat pups were treated with propofol, sevoflurane, or saline on the sixth postnatal day. The long-term effects of prolonged propofol and sevoflurane anesthesia on epileptogenesis were assessed using corneal kindling, pilocarpine-, and pentylenetetrazole-induced seizure models in adult animals. Body weight gain was measured throughout the experiment. No changes in the seizure threshold were observed in the three models. A significant weight gain after exposure to anesthetics during synaptogenesis was observed in the propofol group but not in the sevoflurane group. The results suggest that single prolonged exposure to sevoflurane or propofol during synaptogenesis may have no undesirable effects on epileptogenesis in adulthood.

Combinatorial Regimen of Carbamazepine and Imipramine Exhibits Synergism against Grandmal Epilepsy in Rats: Inhibition of Pro-Inflammatory Cytokines and PI3K/Akt/mTOR Signaling Pathway

Epilepsy is a neurodegenerative disorder that causes recurring seizures. Thirty-five percent of patients remain refractory, with a higher prevalence of depression. We investigated the anticonvulsant efficacy of carbamazepine (CBZ; 20 and 50 mg/kg), imipramine (IMI; 10 and 20 mg/kg) alone, and as a low dose combination. This preclinical investigation included dosing of rats for 14 days followed by elicitation of electroshock on the last day of treatment. Along with behavioral monitoring, the rat hippocampus was processed for quantification of mTOR, IL-1β, IL-6 and TNF-α levels. The histopathological analysis of rat hippocampus was performed to ascertain neuroprotection. In vitro studies and in silico studies were also conducted. We found that the low dose combinatorial therapy of CBZ (20 mg/kg) + IMI (10 mg/kg) exhibits synergism (p < 0.001) in abrogation of maximal electroshock (MES) induced convulsions/tonic hind limb extension (THLE), by reducing levels of pro-inflammatory cytokines, and weakening of the PI3K/Akt/mTOR signal. The combination also exhibits cooperative binding at the Akt. As far as neuroprotection is concerned, the said combination increased cell viability by 166.37% compared to Pentylenetetrazol (PTZ) treated HEK-293 cells. Thus, the combination of CBZ (20 mg/kg) + IMI (10 mg/kg) is a fruitful combination therapy to elevate seizure threshold and provide neuroprotection.

Case Report: “Niemann-Pick Disease Type C in a Catatonic Patient Treated With Electroconvulsive Therapy”

We describe a case of an adolescent male with Niemann-Pick Type C (NP-C), a neurodegenerative lysosomal lipid storage disorder, who presented with recurrent catatonia which required repeated treatment with electroconvulsive therapy (ECT). During the ECT-course, seizure threshold increased substantially, leading to questions about the influence of NP-C on neuronal excitability. In this exemplary ECT-patient, NP-C was diagnosed not until after the first ECT-course when initial psychopharmacology for catatonia had failed and antipsychotics and benzodiazepines showed significant side-effects. Clinicians should be aware of NP-C in patients referred for ECT, especially in the case of treatment resistance, neurological symptoms and intolerance of psychopharmacological drugs. As was shown in our NP-C patient, ECT can be repeatedly effective for catatonic features. In the literature, effectiveness of ECT in patients with NP-C has sparsely been reported. This case demonstrates that detection of NP-C is beneficial for patients because more optimal treatment with ECT can be provided earlier without further exposure to side-effects.

The SZT2 Interactome Unravels New Functions of the KICSTOR Complex

Seizure threshold 2 (SZT2) is a component of the KICSTOR complex which, under catabolic conditions, functions as a negative regulator in the amino acid-sensing branch of mTORC1. Mutations in this gene cause a severe neurodevelopmental and epileptic encephalopathy whose main symptoms include epilepsy, intellectual disability, and macrocephaly. As SZT2 remains one of the least characterized regulators of mTORC1, in this work we performed a systematic interactome analysis under catabolic and anabolic conditions. Besides numerous mTORC1 and AMPK signaling components, we identified clusters of proteins related to autophagy, ciliogenesis regulation, neurogenesis, and neurodegenerative processes. Moreover, analysis of SZT2 ablated cells revealed increased mTORC1 signaling activation that could be reversed by Rapamycin or Torin treatments. Strikingly, SZT2 KO cells also exhibited higher levels of autophagic components, independent of the physiological conditions tested. These results are consistent with our interactome data, in which we detected an enriched pool of selective autophagy receptors/regulators. Moreover, preliminary analyses indicated that SZT2 alters ciliogenesis. Overall, the data presented form the basis to comprehensively investigate the physiological functions of SZT2 that could explain major molecular events in the pathophysiology of developmental and epileptic encephalopathy in patients with SZT2 mutations.

432 - Ultrabrief Right Unilateral ECT in Older Adults with Catatonia: A Case Series and Literature Review

Objectives:Comparing Ultra-brief (UB) Right Unilateral Electroconvulsive Therapy (RU ECT) to the existing literature, this case series highlights the use of the treatment with geriatric patients.Methods:This is a retrospective chart review of 5 patients with catatonia who were successfully treated with UB RUL ECT. Medical records were reviewed for clinical data and ECT treatment. The existing literature is compared and contrasted with other published cases. Quick Inventory of Depressive Symptomatology (QIDS) was completed both pre-ECT and post-ECT. Clinical Global Impression–Improvement (CGI-I) scale was performed post-ECT. Response was defined as decrease of QIDS by 50% and remission was defined as QIDS ≤5. CGI response was defined as CGI-I ≤2.Results:All patients received UB RUL ECT treatment (mean age 67, 100% female). 20% (n=2) were caucasian. 60% had mood disorders and 40% had psychotic disorders. Number of treatments in the acute treatment course ranged from 5 to 20, charge was dosed at 6-10 times the seizure threshold determined at first treatment. All patients had a significant clinical response to ECT as reflected by clinical data, ECT procedure notes, and rating scales when available. All patients completed post ECT CGI-I. Response rate was 60% (n = 3). We also assessed QIDS scores for patients with comorbid depression. Out of these patients, 40% (n = 2) were unable to complete baseline QIDS secondary to symptoms severity. Mean baseline QIDS for the remaining patients was 9.67 (SD 1.53). Post-treatment QIDS was 3.67 (SD 5.51). Paired-samples t-test comparing these scores at baseline and post-ECT demonstrated a significance P value of 0.14. None of the patients experienced worsening of cognitive function.Conclusions:UB RUL ECT is a safe and effective treatment for Catatonia. Our data demonstrate clinical improvement in patients with Catatonia with UB RUL ECT. In addition, this method may lower the burden of cognitive effects that can significantly benefit the older adult population. The literature is limited regarding the use of Ultra-brief (<0.37 milisec) Right Unilateral (RU) ECT in Catatonia. Additional studies will benefit from the inclusion of objective metrics such as Bush Francis Catatonia Scale, Scale for the Assessment of Psychotic Symptoms (SAPS), and the systematic evaluation of cognitive status and function.