Seizure Severity Score Research Articles

Adjuvant indoleamine 2,3-dioxygenase enzyme inhibition for comprehensive management of epilepsy and comorbid depression

Epilepsy is one of the major neurological disorders frequently associated with psychiatric disorders such as depression. Alteration of tryptophan metabolism towards kynurenine pathway may be one of the plausible reasons for association of depression in epilepsy. Hence, this study was envisaged to evaluate the dose dependent inhibition of indoleamine 2,3-dioxygenase (IDO) enzyme (responsible for shifting tryptophan metabolism) employing minocycline with valproic acid for comprehensive management of epilepsy and comorbid depression. Kindling was induced in male swiss albino mice by administration of pentylenetetrazole subconvulsive dose (35mg/kg, i.p.) at an interval of 48±2h. Kindled animals were treated with saline, valproate (300mg/kg/day i.p.), valproate in combination with different doses of minocycline (10mg/kg; 20mg/kg; 40mg/kg)/day i.p. and minocycline per se (40mg/kg/day i.p.) for 15 days. Except naïve, all the groups were challenged with pentylenetetrazole (35mg/kg i.p.) on day 5, 10, and 15 to evaluate the seizure severity score. Depression was evaluated in all experimental groups using tail suspension and forced swim test on days 1, 5, 10 and 15, 2h after pentylenetetrazole challenge. Results suggested that saline treated kindled animals were significantly associated with depression. Chronic valproate treatment significantly reduced seizure severity score but unable to ameliorate the associated depression. Minocycline supplementation with valproic acid dose dependently ameliorated depression associated with epilepsy. Neurochemical and biochemical findings also supported the behavioural findings of the study. Thus, our results suggested that supplementation of IDO enzyme inhibitors with valproic acid could be explored further for comprehensive management of epilepsy and associated depression.

A randomized controlled trial of the ketogenic diet in refractory childhood epilepsy.

To evaluate the efficacy and tolerability of the ketogenic diet (KD) during the first 4 months of a randomized controlled trial (RCT) in refractory epilepsy patients aged 1-18 years. Children and adolescents with refractory epilepsy, not eligible for epilepsy surgery, were included. Following 1 month at baseline, patients were randomized to either the KD or to care as usual (CAU).Primary outcome is the proportion of patients with at least 50% reduction in seizure frequency at 4 months. Secondary outcomes are mean percentage of baseline seizures, seizure severity, and side effects. Fifty-seven patients were randomized; nine dropped out, leaving 48 for analysis (i.e., 26 KD, 22 CAU). In an intention-to-treat analysis, 13 patients (50%) treated with the KD and four patients (18.2%) of the CAU group were responders.Mean seizure frequency at 4 months compared to baseline, after removal of two outliers in the KD group, was significantly lower (P = 0.024) in the KD group (56%) (95% CI: 36-76) than in the CAU group (99%) (95% CI: 65-133%).Twice as many patients in the KD group had a relevant decrease in seizure severity score (P = 0.070).Patients treated with the KD had a significantly higher score for gastrointestinal symptoms (P = 0.021) without an increase in the total score of side effects. This trial provides class I evidence that the KD is an effective therapy in children and adolescents with refractory epilepsy compared with CAU. Most often reported side effects are gastrointestinal symptoms.The study has been registered with the Netherlands Trial Registry (NTR2498).

Anticonvulsant Effect of Time-Restricted Feeding in a Pilocarpine-Induced Seizure Model: Metabolic and Epigenetic Implications.

A new generation of antiepileptic drugs has emerged; however, one-third of epilepsy patients do not properly respond to pharmacological treatments. The purpose of the present study was to investigate whether time-restricted feeding (TRF) has an anticonvulsant effect and whether this restrictive diet promotes changes in energy metabolism and epigenetic modifications in a pilocarpine-induced seizure model. To resolve our hypothesis, one group of rats had free access to food and water ad libitum (AL) and a second group underwent a TRF schedule. We used the lithium-pilocarpine model to induce status epilepticus (SE), and behavioral seizure monitoring was analyzed. Additionally, an electroencephalography (EEG) recording was performed to verify the effect of TRF on cortical electrical activity after a pilocarpine injection. For biochemical analysis, animals were sacrificed 24 h after SE and hippocampal homogenates were used to evaluate the proteins related to metabolism and chromatin structure. Our results showed that TRF had an anticonvulsant effect as measured by the prolonged latency of forelimb clonus seizure, a decrease in the seizure severity score and fewer animals reaching SE. Additionally, the power of the late phase EEG recordings in the AL group was significantly higher than the TRF group. Moreover, we found that TRF is capable of inducing alterations in signaling pathways that regulate energy metabolism, including an increase in the phosphorylation of AMP dependent kinase (AMPK) and a decrease in the phosphorylation of Akt kinase. Furthermore, we found that TRF was able to significantly increase the beta hydroxybutyrate (β-HB) concentration, an endogenous inhibitor of histone deacetylases (HDACs). Finally, we found a significant decrease in HDAC activity as well as an increase in acetylation on histone 3 (H3) in hippocampal homogenates from the TRF group. These findings suggest that alterations in energy metabolism and the increase in β-HB mediated by TRF may inhibit HDAC activity, thus increasing histone acetylation and producing changes in the chromatin structure, which likely facilitates the transcription of a subset of genes that confer anticonvulsant activity.

Bromocriptine Mesylate Protects against Status Epilepticus and Temporal Lobe Epilepsy: Neurobehavioral, Histopathological and Neurochemical Evidences

Background: Dopamine (DA) plays a major role in the control of epileptic seizures arising in the limbic system, through D1/D2 receptor-mediated signaling. Objective: The study was intended to investigate whether bromocriptine mesylate (BRC), a dopamine (D2) receptor agonist, has an anti-seizure property, attenuates oxidative stress and neuronal morphological alterations against pilocarpine induced status epilepticus (SE) in mice, using sodium valproate (SVP) as comparator AED. Materials and Methods: SVP (300 mg/kg) and BRC (6 &10 mg/kg) were administered orally once daily for a period of 4 weeks followed by pilocarpine (300 mg/kg, i.p) to induce SE. The convulsions Original Research Article Pottoo et al.; INDJ, 6(4): 1-13, 2016; Article no.INDJ.24401 2 were monitored for 2 hrs post pilocarpine injection. At 2 hrs post pilocarpine injection hippocampal malondialdehyde, glutathione reduced, glutathione peroxidase, glutathione reductase and catalase activities were measured. While hippocampal histopathological assessment of neuronal injury was performed 24 hrs post pilocarpine injection. Results: We report that SVP (300 mg/kg) and BRC (6 &10 mg/kg) were able to reduce seizure severity score (P<0.001, P<0.01, P<0.05), attenuate oxidative damage in lipids and proteins, restore depletion in hippocampal glutathione reduced, glutathione peroxidase and glutathione reductase activities compared to toxic/pilocarpine control. Contrary catalase levels were strengthened as like pilocarpine control. In addition SVP (300 mg/kg) and BRC (6 & 10 mg/kg) protected against degeneration in hippocampal CA1, CA2, CA3 & DG regions (P<0.001, P<0.01, P<0.05) compared to pilocarpine control. Conclusions: The present study highlights the prominent dysregulation of dopaminergic system in seizures and perspectives for the development of novel therapeutic approaches acompassing dopaminergic drugs in amelioration of epileptic seizures especially status-epilepticus and temporal lobe epilepsy.

Time to treatment predicts seizure outcome in a high-treatment gap epilepsy population

ObjectivesTo investigate the relationship between time to antiepileptic drug (AED) treatment (TTT) and seizure outcome in a high treatment gap sub-Sahara African setting. MethodsClinical and demographic characteristics of 72 adults with epilepsy aged 18–75 years were obtained. We estimated TTT as the difference between the duration of epilepsy and the duration of treatment. Indices of clinical outcome including seizure severity and 6-month disease remission were documented. The effects of TTT and other clinical and demographic characteristics on clinical outcomes were tested using bivariate and logistic regression analyses. ResultsForty (55.6%) of the participants initiated treatment within 5 years of seizure onset (TTT≤5 years) while 32 (44.4%) initiated treatment after 5 years (TTT>5 years). There was moderate to strong correlation between TTT and age of onset (p=.009), age at treatment initiation (p=.026), duration of epilepsy (p=.000), and seizure severity (p=.020). The TTT>5 years group had an earlier mean age of onset (p=.015) and higher seizure severity score (p=.001) and were less likely to be in 6-month disease remission (p=.014). Time to treatment ≤5 years was the only independent predictor of lesser seizure severity (OR=0.163, 95% CI=0.041–0.649) and better 6-month remission (OR=0.154, 95% CI=0.031–0.770) after adjusting for age of onset, duration of epilepsy, and number of AEDs. ConclusionDelayed treatment initiation is common in our sample and independently associated with poor seizure outcome.

Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice

Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17β-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17β-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids.

Protective effect on phenytoin-induced cognition deficit in pentylenetetrazol kindled mice: A repertoire of Glycyrrhiza glabra flavonoid antioxidants

Context: Glycyrrhiza glabra L. (Febaceae) has been widely used in traditional medicine and scientifically explored for its anticonvulsant and memory improving potential.Objective: The objective of this study is to investigate the effect of flavonoid rich fraction of G. glabra root extract against phenytoin-induced cognition deficit in pentylenetetrazol (PTZ) kindled mice.Materials and methods: The ethyl acetate fraction was initially screened in different in vitro free radical scavenging assays. For in vivo studies, the kindled mice in different groups were given 15 d post-treatment with phenytoin (25 mg/kg; p.o.) per se or in combination with varying doses of the fraction (5, 10, and 15 mg/kg; p.o.). Seizure severity score and cognitive functions were accessed using Racine's scale and passive shock avoidance paradigm, respectively on every 5th d after a PTZ challenge dose (35 mg/kg; i.p.). At the end of study, the animals were scarified for cerebral biochemistry.Results: The fraction showed marked antioxidant activity indicated by low IC50 values in DPPH (20.9 µg/mL), nitric oxide radical scavenging (195.2 µg/mL), and capacity of hydrogen peroxide scavenging (3.4 µg/mL) assays. Treatment with phenytoin per se and along with the flavonoid rich fraction showed significant reduction in seizure severity score as compared to vehicle control. The combined-treated groups also showed improved cognitive functions indicated by reduced number of mistakes and increased step-down latency in passive shock avoidance paradigm.Conclusion: From the results, it can be concluded that the flavonoid rich fraction in combination with phenytoin reduces seizure severity and improve cognitive functions in PTZ-kindled mice.

Variable electrobehavioral patterns during focal nonconvulsive status epilepticus induced by unilateral intrahippocampal injection of kainic acid.

Nonconvulsive status epilepticus (ncSE) is a severe condition that may result in neurologic sequelae and epilepsy resistant to pharmacologic treatment. We analyze here seizure and electroencephalography (EEG) patterns and their correlation to the development of a chronic epileptic condition in a guinea pig model of focal ncSE induced by intrahippocampal injection of kainic acid (KA). Electrobehavioral patterns during ncSE induced by unilateral injection of 1μg of KA in the CA1 region of the hippocampus were characterized by continuous video-EEG monitoring in 13 guinea pigs bilaterally implanted with recording electrodes in the hippocampus and neocortex. Video-EEG analysis demonstrates a high variability of seizure type and duration during KA-induced ncSE. Seizures showed focal signs correlated with diverse epileptiform EEG discharge distributions, either diffuse or localized. Nonfocal (bilateral motor) signs during seizures most likely correlated with a diffuse EEG pattern. The evolution into a chronic epileptic condition correlated neither with the severity of seizure pattern nor with the diffusion of the EEG discharges observed during the ncSE. Video-EEG monitoring in a guinea pig model of ncSE induced by unilateral hippocampal injection of KA demonstrates a high variability of electrobehavioral patterns. We demonstrate that the seizure severity score during focal ncSE is not a predictor of the evolution into a chronic epileptic condition of mesial temporal lobe epilepsy.

Ficus religiosa L. figs — A potential herbal adjuvant to phenytoin for improved management of epilepsy and associated behavioral comorbidities

Oxidative stress, together with mitochondrial dysfunction, has been reported to be involved in the pathogenesis of epileptogenesis and its associated comorbidities. Phytoflavonoids have shown numerous beneficial ameliorative effects on different neurological disorders by virtue of their antioxidant effect. The present study investigated the effect of flavonoid-rich ethyl acetate fraction of the crude fig extract of Ficus religiosa in combination with phenytoin on seizure severity, depressive behavior, and cognitive deficit in pentylenetetrazol (PTZ)-kindled mice. The flavonoid-rich ethyl acetate fraction of the crude fig extract was found to show significant antioxidant potential in various in vitro free radical scavenging assays. Combined treatment of this fraction (2.5, 5, and 10mg/kg; i.p.) along with a subeffective dose of phenytoin (15mg/kg; i.p.) in postkindled animals once daily for fifteen days showed a dose-dependent decrease in the seizure severity score, a decreased number of mistakes, increased step-down latency in passive shock avoidance paradigm, and decreased immobility time in the tail suspension test in comparison with the phenytoin only-treated group. Biochemical investigations of the brain tissue showed amelioration of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) levels, and reduced catalase and acetylcholinesterase (AChE) activities, thereby indicating suppression of oxidative stress. In conclusion, the results of the present study showed the protective effect of the flavonoid-rich fraction of F. religiosa along with a subeffective dose of phenytoin in PTZ-kindling-associated cognitive deficit and depressive behavior with complete suppression of seizures through reduction of oxidative stress, supporting the the need for clinical evaluation of the supplementation of phytoflavonoids along with antiepileptic drugs (AEDs) for management of epilepsy and its psychiatric and cognitive comorbidities.

Raloxifene protects against seizures and neurodegeneration in a mouse model mimicking epilepsy in postmenopausal woman

Epilepsy in menopausal women presents several challenges in the treatment including an increased risk of seizures due to hormone replacement therapy. We investigated the hypothesis if raloxifene, a selective oestrogen receptor modulator, could be employed to prevent behavioural seizures and morphological alterations in a mouse model mimicking epilepsy in postmenopausal women. Female mice were made ovotoxic by treatment with 4-vinylcyclohexene diepoxide (VCD) to mimic a postmenopausal state. They were then subjected to kainic acid (KA)-induced seizures and neurotoxicity, as assessed by microscopic examination of hippocampus, relevant to human temporal lobe epilepsy. VCD administration (for 15days followed by a drug-free period of 30days) induced ovotoxicity in mice as evidenced by reduced number of primary ovarian follicles. This was accompanied by a 62.4% reduction in serum oestradiol levels. The bone mineral density of ovotoxic mice, however, remained unaffected. Raloxifene (8mg/kg) reduced the seizure severity score in both normal and ovotoxic mice and protected against degeneration induced by KA in the CA3, CA1 sub-fields and hilus of the DG. Hippocampal TGF-β3 levels were not affected by any of the treatments. We show the potential protective role of raloxifene in preventing seizures and neuronal damage in a mouse model mimicking epilepsy in postmenopausal women which was found unrelated to hippocampal TGF-β3. Raloxifene might represent a novel therapeutic option for postmenopausal temporal lobe epileptic woman.

Adjuvant Anticholinesterase Therapy for the Management of Epilepsy‐Induced Memory Deficit: A Critical Pre‐clinical Study

Epilepsy is one of the major neurological disorders still awaiting safer drugs with improved antiepileptic effect and lesser side effects. Apart from epilepsy itself, AEDs also have been shown to induce cognitive impairment in patients with epilepsy. There are limited data for the treatment of this menace. As cholinergic approach has widely been practiced for the restoration of memory in various neurodegenerative disorders, this study was envisaged to evaluate add on effect of acetylcholinesterase inhibitor (tacrine) with phenytoin in pentylenetetrazole-kindling-induced learning and memory deficit in mice. In this study, mice were kindled using subconvulsive dose of pentylenetetrazole (35mg/kg, i.p.; at interval of 48±2hr) and successfully kindled animals were divided into different groups and treated with vehicle, phenytoin and phenytoinin in combination with tacrine (0.3mg/kg), atropine (1mg/kg) and tacrine + atropine. Effect of different interventions on learning and memory was evaluated using elevated plus maze and passive shock avoidance on days 5, 10, 15 and 20. Phenytoin-treated kindled animals were associated with learning and memory deficit, while tacrine supplementation improved memory deficit with increased seizure severity score. Atropine treatment significantly reversed the protective effect of tacrine. Neurochemical findings also support the behavioural finding of the study. Our results suggest the use of anticholinesterases, with better seizure tolerance, for the management of cognitive impairment of epilepsy, as adjunct therapy.

Glutamate receptor antibodies directed against AMPA receptors subunit 3 peptide B (GluR3B) can be produced in DBA/2J mice, lower seizure threshold and induce abnormal behavior

Anti-GluR3B antibodies (GluR3B Ab's), directed against peptide B/aa372-395 of GluR3 subunit of glutamate/AMPA receptors, are found in ∼35% of epilepsy patients, activate glutamate/AMPA receptors, evoke ion currents, kill neurons and damage the brain. We recently found that GluR3B Ab's also associate with neurological/psychiatric/behavioral abnormalities in epilepsy patients. Here we asked if GluR3B Ab's could be produced in DBA/2J mice, and also modulate seizure threshold and/or cause behavioral/motor impairments in these mice. DBA/2J mice were immunized with the GluR3B peptide in Complete Freund's Adjuvant (CFA), or with controls: ovalbumin (OVA), CFA, or phosphate-buffer saline (PBS). GluR3B Ab's and OVA Ab's were tested. Seizures were induced in all mice by the chemoconvulsant pentylenetetrazole (PTZ) at three time points, each time with less PTZ to avoid non-specific death. Behavior was examined in Open-Field, RotaRod and Grip tests. GluR3B Ab's were produced only in GluR3B-immunized mice, while OVA Ab's were produced only in OVA-immunized mice, showing high Ab's specificity. In GluR3B Ab's negative mice, seizure severity scores and percentages of animals developing generalized seizures declined in response to decreasing PTZ doses. In contrast, both parameters remained unchanged/high in the GluR3B Ab's positive mice, showing that these mice were more susceptible to seizures. The seizure scores associated significantly with the GluR3B Ab's levels. GluR3B Ab's positive mice were also more anxious in Open-Field test, fell faster in RotaRod test, and fell more in Grip test, compared to all the control mice. GluR3B Ab's are produced in DBA/2J mice, facilitate seizures and induce behavioral/motor impairments. This animal model can therefore serve for studying autoimmune epilepsy and abnormal behavior mediated by pathogenic anti-GluR3B Ab's.

Effects of seizure severity and seizure freedom on the health-related quality of life of an African population of people with epilepsy

PurposeThis study aimed at determining the effects of seizure severity and seizure freedom on health-related quality of life (HRQOL) of people with epilepsy (PWE) in the presence of perceived stigma in a sub-Saharan African culture. MethodsHealth-related quality of life was assessed using QOLIE-31 in 93 consecutive adults (56 males and 37 females) with epilepsy. They were stratified into seizure-free, low–moderate seizure severity, and high seizure severity groups based on the seizure type and the number of seizures in the previous 6months. Other illness variables and sociodemographic variables were also obtained. A 3-item perceived stigma scale was administered. A modified QOLIE-31 (excluding the epilepsy-specific items) was given to 102 age- and sex-matched healthy controls. ResultsThere was moderate negative correlation between seizure severity and mean total HRQOL score as well as scores on the Seizure Worry (p=.000), Overall Quality of Life (p=.000), and Social Function (p=.001) subscales of QOLIE-31. Overall, the healthy control subjects had a higher mean HRQOL score compared with the PWE put together (71.0+11.1 vs 64.2±13.6, p=.001). However, there was no difference in the mean HRQOL score between the seizure-free individuals and the healthy controls (p=.270). Seizure severity was associated with HRQOL independent of perceived stigma on a multiple regression analysis. ConclusionThis study provides evidence that seizure severity relates to health-related quality of life in an inverse, graded manner and independent of perceived stigma. Seizure-free people with epilepsy can have quality of life comparable with healthy individuals.

Pharmacological and neuroethological studies of three antiepileptic drugs in the Genetic Audiogenic Seizure Hamster (GASH:Sal)

Epilepsy modeling is essential for understanding the basic mechanisms of the epileptic process. The Genetic Audiogenic Seizure Hamster (GASH:Sal) exhibits generalized tonic–clonic seizures of genetic origin in response to sound stimulation and is currently being validated as a reliable model of epilepsy. Here, we performed a pharmacological and neuroethological study using well-known and widely used antiepileptic drugs (AEDs), including phenobarbital (PB), valproic acid (VPA), and levetiracetam (LEV). The intraperitoneal administration of PB (5–20mg/kg) and VPA (100–300mg/kg) produced a dose-dependent decrease in GASH:Sal audiogenic seizure severity scores. The administration of LEV (30–100mg/kg) did not produce a clear effect. Phenobarbital showed a short plasmatic life and had a high antiepileptic effect starting at 10mg/kg that was accompanied by ataxia. Valproic acid acted only at high concentrations and was the AED with the most ataxic effects. Levetiracetam at all doses also produced sedation and ataxia side effects. We conclude that the GASH:Sal is a reliable genetic model of epilepsy suitable to evaluate AEDs.

Seizure severity and health-related quality of life of adult Nigerian patients with epilepsy

There is paucity of information about the association of seizure severity and quality of life in people with epilepsy (PWE) in sub-Saharan Africa. We evaluated the relationship of seizure severity to health-related quality of life of patients with epilepsy being followed up in an outpatient neurology clinic in southwestern Nigeria. Eighty-eight consecutive patients with epilepsy who met the recruitment criteria completed the study questionnaire in company of an eyewitness. The study questionnaire comprised of the National Hospital Seizure Severity Scale (NHS3), the Quality of Life Inventory in Epilepsy (QOLIE-31), and the Beck's Depression Inventory-II (BDI-II). We found a minute association between seizure severity and QOLIE-31 total score (r = -0.262, P = 0.014). Increased seizure severity predicted a worse QOLIE-31 seizure worry (R(2) = 0.311, β = -0.289; P = 0.003). Of the seven seizure severity items, generalization of seizures and presence of falls were items that predicted a worse QOLIE-31 seizure worry score and time to recover predicted a worse QOLIE-31 total score. Reducing seizure severity may be an alternate endpoint in epilepsy care in Nigeria (particularly difficult to control seizures) because of its practical clinical relevance in view of the fact that state-of-the-art epilepsy care is still farfetched.

Influence of hypo-osmolality and induced seizures on blood brain barrier permeability and brain concentrations of trace elements in rats

Backgrounds: We studied the changes in blood-brain barrier (BBB) permeability and brain trace elements concentration in acute hypo-osmolality and pentylenetetrazol (PTZ)-induced seizures model in rats. Furthermore, the effect of acute hypo-osmolality on seizure activity (patterns) in the PTZ model, the correlation between seizure severity score (SS score) and changes of both of BBB permeability and brain trace elements concentration in rats were also studied. Materials and Methods: Four groups (18 animals /group) of adult male albino rats were included. The animal groups are: (1) Control group: received only a vehicle. (2) Hypo-osmolar group: received warm distilled water (DW). (3) Seizure group: injected with PTZ i.p. (4) Hypo-osmolar + seizure group: first injected with DW and then PTZ. During the next 30 minutes, the animals were observed for seizure activity. For evaluation of BBB permeability changes, serum S100B protein and Evan Blue (EB) dye content of brain tissue were evaluated. Additionally macroscopic and microscopic examinations of brain tissue were completed. Trace elements, magnesium (Mg), zinc (Zn), copper (Cu) and iron (Fe), concentration in brain tissue were estimated. Results: There were significant increase of EB content of brain tissue, and serum S100ß in hypo-osmolar, seizure and hypo-osmolar + seizure groups, as compared with control animals. These parameters were significantly increased in the hypo-osmolar + seizure group when compared with either hypo-osmolar or seizure groups. These results were confirmed by macroscopic examination of brain tissue. Trace elements concentration of brain tissue, Mg, Zn, Cu and Fe, were significantly decreased in hypo-osmolar, seizure and hypo-osmolar + seizure groups in comparison with control animals. Histological examination of sections from the hilar region of dentate gyrus of the hippocampus revealed degenerative changes in the three groups of animals in comparison with control animals. Morphometric analysis showed a significant decrease in the number of cells in the hilar region of dentate gyrus in the three groups of animals in comparison with controls. Seizure activity significantly increased in hypo-osmolar + seizure as compared to seizure group. The correlation analysis revealed that significant −ve correlations were found between SS score and trace elements concentration, while significant +ve correlations were observed between SS score, and each of EB content and serum S100ß protein in seizure and hypo-osmolar + seizure groups. Conclusion: Our study demonstrated that, hypo-osmolality and PTZ-induced seizures could result in increased BBB permeability with a decrease of brain trace elements concentration. This could play a vital role in the pathophysiology of epileptic seizures. In addition, hypo-osmolality can enhance neuronal excitability and severity of seizures in the PTZ-induced model in rats.

Ameliorative effect of Curcumin on seizure severity, depression like behavior, learning and memory deficit in post-pentylenetetrazole-kindled mice

Epilepsy is a chronic neurological disorder and generally associated with certain psychiatric comorbidities. Among several comorbidities depressive behavior and cognitive impairment has been reported to be most debilitating comorbidity associated with epilepsy. This study was envisaged to evaluate the ameliorative effect of Curcumin on depression like behavior and cognitive impairment observed in pentylenetetrazole kindled animals. Male Swiss Albino mice were kindled with subconvulsive dose of pentylenetetrazole (35mg/kg, i.p.). Successfully kindled animals were used in the study to observe the effect of different treatments. Treatment groups received phenytoin (30mg/kg) and Curcumin (50, 100 and 200mg/kg) for 15 days. The animals were challenged with pentylenetetrazole (35mg/kg, i.p.) on day 5, 10 and 15 and seizure severity score, immobility period, number of mistakes and step down latency were recorded. On 15th day, all the animals were sacrificed after behavioral evaluations and their brain was isolated and homogenized to estimate brain norepinephrine, serotonin, total nitrite level and acetylcholinesterase activity. Phenytoin treatment significantly improved the depressive like behavior along with its anticonvulsant effect, however was unable to improve memory impairment. Curcumin significantly attenuated seizure severity, depression like behavior and memory impairment in kindled animals, in dose dependent manner. These results were supported by the biochemical modulation of brain monoamine, nitrosative stress level and acetylcholinesterase activity. Thus present study concluded that Curcumin has the ameliorative effect on seizure severity, depression like behavior and memory impairment in pentylenetetrazole kindled mice, possibly via central monoaminergic modulation and inhibitory effect on nitrosative stress and acetylcholinesterase activity.

Probing the role of the sodium/calcium exchanger in pentylenetetrazole-induced generalized seizures in rats

The Na⁺/Ca²⁺ exchanger (NCX) is thought to play an important role in the pathogenesis of pentylenetetrazole (PTZ)-induced tonic flexion in mice. Here, I investigated the expression of PTZ-induced generalized clonic and tonic-clonic seizures in rats, using two potent NCX reverse mode inhibitors, KB-R7943 and SN-6 for NCX subtypes 3 (NCX3) and 1 (NCX1), respectively. Pretreatment with KB-R7943 (3, 10, and 30 mg/kg; p.o.) significantly reduced the expression of PTZ-induced generalized seizures with clonic and tonic-clonic components in 12-62% and 25-62% of the treated animals, respectively. In the remaining animals that exhibited seizures, KB-R7943 (3 mg/kg; p.o.) pretreatment significantly delayed the onset of the first seizure episode and reduced the seizure severity. Following pretreatment with SN-6 (0.3, 1, 3, 10, and 30 mg/kg; p.o.), clonic and tonic-clonic PTZ-induced generalized seizures were reduced in 25-50% and 38-63% of treated animals, respectively. SN-6 (0.3, 1, and 3 mg/kg; p.o.) also significantly reduced PTZ-induced seizure severity scores, but did not alter seizure latencies. KB-R7943 (3 and 30 mg/kg; p.o.) or SN-6 (3 and 30 mg/kg; p.o.) administration potentiated the sub-anticonvulsant dose of diazepam (2.5 mg/kg; i.p.) that suppresses clonic and tonic-clonic PTZ-induced seizures. These findings suggested that Ca²⁺ influx via the NCX in reverse mode contributes to a neuronal hyperexcitability that leads to clonic and tonic-clonic generalized seizures and that the NCX1 and NCX3 isoforms may serve as novel molecular targets for seizure suppression.

Influence of carbenoxolone on the anticonvulsant efficacy of phenytoin in pentylenetetrazole kindled rats.

Abnormal synchronized neuronal discharges mediated by gap junctions have an important role in epileptic seizures. The analysis of anticonvulsant drugs acting on gap junctions is still a priority in epilepsy research. Therefore, the present study was designed to investigate the effect of carbenoxolone, a gap junction blocker, on the anticonvulsant efficacy of phenytoin in pentylenetetrazole kindled rats. Male Wistar albino rats, 14 weeks of age, were used. In the first step of the study, animals were given PTZ 35 mg/kg intraperitoneally (i.p.) three times a week until kindling was produced. Then, indwelling screw electrodes - allowing EEG monitoring of conscious rats - were implanted into the crania of the kindled rats. In this way, we were able to record EEG activity and evaluate seizure stage at the same time. In the second step of the study, the interaction between carbenoxolone (40 mg/kg i.p.) and phenytoin (60 mg/kg, i.p.) was investigated. The data analysis was performed using a one-way ANOVA with LSD post-hoc test. Total spike number and the generalized seizure duration were reduced in the carbenoxolone treated group compared to the PTZ group. Phenytoin decreased generalized seizure duration, total spike number and seizure severity score. Carbenoxolone and phenytoin have anti-seizure effects in PTZ kindled rats. There was no significant difference between the carbenoxolone + phenytoin combination and phenytoin in terms of generalized seizure duration, total spike number and seizure stage. The results indicate that carbenoxolone combined with phenytoin is not more effective than the use of these drugs alone.

Noninvasive Transcranial Focal Stimulation Via Tripolar Concentric Ring Electrodes Lessens Behavioral Seizure Activity of Recurrent Pentylenetetrazole Administrations in Rats

Epilepsy affects approximately 1% of the world population. Antiepileptic drugs are ineffective in approximately 30% of patients and have side effects. We have been developing a noninvasive transcranial focal electrical stimulation with our novel tripolar concentric ring electrodes as an alternative/complementary therapy for seizure control. In this study we demonstrate the effect of focal stimulation on behavioral seizure activity induced by two successive pentylenetetrazole administrations in rats. Seizure onset latency, time of the first behavioral change, duration of seizure, and maximal seizure severity score were studied and compared for focal stimulation treated (n = 9) and control groups (n = 10). First, we demonstrate that no significant difference was found in behavioral activity for focal stimulation treated and control groups after the first pentylenetetrazole administration. Next, comparing first and second pentylenetetrazole administrations, we demonstrate there was a significant change in behavioral activity (time of the first behavioral change) in both groups that was not related to focal stimulation. Finally, we demonstrate focal stimulation provoking a significant change in seizure onset latency, duration of seizure, and maximal seizure severity score. We believe that these results, combined with our previous reports, suggest that transcranial focal stimulation may have an anticonvulsant effect.