Impact of timing of antiseizure medication withdrawal on seizure recurrence in glioma patients: a retrospective observational study

BACKGROUND

Withdrawal of antiseizure medication treatment (ASM) can be considered after completion of antitumour treatment in glioma patients who no longer suffer from seizures. We compared the risk for recurrent seizures after ASM withdrawal between patients with short-term, medium-term versus long-term seizure freedom after antitumour treatment.

METHODS

In this retrospective observational study, the primary outcome was time to recurrent seizure, from the starting date of no ASM treatment up to 36 months follow-up. Cox proportional hazards models were used to study the effect of risk factors on time to recurrent seizure. Stratification was done with information known at baseline. Short-term seizure freedom was defined as ≥ 3 months, but < 12 months; medium-term as 12-24 months; and long-term as ≥ 24 months seizure freedom from the date of last antitumour treatment.

RESULTS

This study comprised of 109 patients; 31% (34/109) were in the short-term, 29% (32/109) in the medium-term, and 39% (43/109) in the long-term group. A recurrent seizure was experienced by 47% (16/34) of the patients in the short-term, 31% (10/32) in the medium-term, and 44% (19/43) in the long-term group. Seizure recurrence risk was similar between patients in the short-term group as compared to the medium-term (cause-specific adjusted hazard ratio [aHR] = 0.65 [95%CI = 0.29-1.46]) and long-term group (cause-specific aHR = 1.04 [95%CI = 0.52-2.09]).

CONCLUSIONS

Seizure recurrence risk is relatively similar between patients with short-term, medium-term, and long-term seizure freedom after completion of antitumour treatment.

The challenges to control epilepsy in an isolated indigenous tribe in Brazil's Amazon: 15 years of follow-up

BACKGROUND

Epilepsy is a common neurological disease that affects people all over the world, but it is rarely described in indigenous peoples.

OBJECTIVE

To study the epilepsy characteristics and risk factors for seizure control in people from an isolated indigenous population.

METHODS

This is a retrospective and historical cohort study conducted from 2003 to 2018 (15 years), at a neurology outpatient clinic, of 25 Waiwai tribes' indigenous individuals with epilepsy, inhabitants of an isolated forest reserve in the Amazon. Clinical aspects, background, comorbidities, exams, treatment, and response were studied. Factors that impacted seizure control over 24 months were identified using Kaplan-Meier curves and Cox and Weibull regression models.

RESULTS

The majority of cases started in childhood, with no difference regarding gender. Focal epilepsies were predominant. Most patients had tonic-clonic seizures. A quarter of them had a family history, and 20% had referred febrile seizures. There was intellectual disability in 20% of patients. Neurological examination and psychomotor development were altered in one third of the participants. The treatment controlled 72% of the patients (monotherapy in 64%). Phenobarbital was the most prescribed anti-seizure medication, followed by carbamazepine and valproate. The most relevant factors that impacted seizure control over time were abnormal neurological exam and family history.

CONCLUSION

Family history and abnormal neurological exam were predicted risk factors for refractory epilepsy. Even in an isolated indigenous tribe, the partnership between the indigenous people and the multidisciplinary team ensured treatment adherence. The public healthcare system must guarantee modern anti-seizure medications, mainly for this vulnerable population, which has no other source of treatment.

[Optimal Use of Perampanel in the Treatment of Patients with Epilepsy Based on the Clinical Evidence and Characteristics]

Perampanel (PER) has been used clinically as monotherapy and adjunctive therapy for focal seizures and as adjunctive therapy for generalized tonic-clonic seizures in epilepsy patients in Japan. In recent years in Japan and worldwide, clinical studies have been conducted on patients with various seizure types of epilepsy. The results have shown that PER has broad spectrum properties. The pooled analysis of controlled trials (PERMIT study) showed PER efficacy in patients with status epilepticus, myoclonic seizures, and absence seizures. In addition, PER has been shown to be safe and effective in patients with juvenile myoclonic epilepsy, Lennox-Gastaut syndrome, and elderly-onset epilepsy that are often difficult to treat with narrow-spectrum ASM. In this review article, we summarize the latest findings on PER, and overview the broad spectrum characteristics of PER. In addition, we discuss the optimal use of PER for patients with epilepsy, focusing on low-dose initiation and on slow titration of PER to minimize adverse events. (Received December 7, 2021; Accepted March 29, 2022; Published July 1, 2022).

Approach to the Medical Treatment of Epilepsy

PURPOSE OF REVIEW

This article discusses the use of antiseizure medications in the treatment of focal and generalized epilepsies using an evidence-based approach.

RECENT FINDINGS

In recent years, several new antiseizure medications with differing mechanisms of action have been introduced in clinical practice, and their efficacy and safety has been evaluated in randomized controlled clinical trials. Currently, all antiseizure medications can prevent seizure occurrence, but they have no proven disease-modifying or antiepileptogenic effects in humans. The choice of therapy should integrate the best available evidence of efficacy, tolerability, and effectiveness derived from clinical trials with other pharmacologic considerations, the clinical expertise of the treating physicians, and patient values and preferences. After the failure of a first antiseizure medication, inadequate evidence is available to inform policy. An alternative monotherapy (especially if the failure is because of adverse effects) or a dual therapy (especially if failure is because of inadequate seizure control) can be used.

SUMMARY

Currently, several antiseizure medications are available for the treatment of focal or generalized epilepsies. They differ in mechanisms of action, frequency of administration, and pharmacologic properties, with a consequent risk of pharmacokinetic interactions. Major unmet needs remain in epilepsy treatment. A substantial proportion of patients with epilepsy continue to experience seizures despite two or more antiseizure medications, with a negative impact on quality of life. Therefore, more antiseizure medications that could provide higher seizure control with good tolerability and that could positively affect the underlying disease are needed.

1-Triacontanol cerotate; isolated from Marsilea quadrifolia Linn. ameliorates reactive oxidative damage in the frontal cortex and hippocampus of chronic epileptic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Marsilea quadrifolia Linn. (MQ) has been used for insomnia and epileptic disorders in traditional Indian medicine. The present study is to isolate the active component responsible for antiepileptic property of MQ by evaluating its ability to minimize the reactive oxidative damage in brain due to chronic epilepsy in rat.

MATERIALS AND METHODS

1-Triacontanol cerotate (1TAC) was isolated after chromatography on a silica gel from dried petroleum ether fraction of methanolic extract of MQ. Acute oral toxicity studies of 1TAC were carried out and efficacy of 1TAC on malondialdehyde (MDA) and reduced glutathione (GSH) production in different brain areas of chronic pentylenetetrazole (PTZ) induced epileptic rats were evaluated.

RESULTS

Our results showed that PTZ-kindled chronic epileptic rats had an increase MDA and decreased GSH concentration in the frontal cortex as well as hippocampus, compared to the normal control. MDA and GSH concentrations in those brain areas were normalized after treatment with sodium valproate (SV) in 200 mg kg(-1)bw; as well as 1TAC in 40 and 80 mg kg(-1)bw doses.

CONCLUSION

Production of reactive oxygen species (ROS) is known to worsen epileptogenesis. The isolated component 1TAC which reduced the reactive oxidative damage in hippocampus and frontal cortex of PTZ kindled rats could be responsible for antiepileptic property of MQ. Its action is found to be dose dependent, with 80 mg kg(-1)bw showing even better efficacy than 200 mg kg(-1)bw of SV.

Case report of a patient with bipolar disorder - migraines and epilepsy

Bipolar disorder; migraines and epilepsy are three prevalent conditions, of which little is understood about their pathophysiological processes. Co-morbidities often present between two of these conditions, but it is uncommon for all three to co-exist in a patient. Here, we present a middle-aged gentleman, seen in the outpatient department of a district general hospital in England, who suffers from severe effects of all three disorders, with no other medical history. Clinical difficulties have arisen in the diagnosis and treatment of his bipolar disorder. Management of his depressive episodes with simple selective serotonin reuptake inhibitors and mood stabilisers were either ineffective, or precipitated complicating adverse effects. Persistent use of citalopram is likely to have triggered bipolar disorder, whilst quetiapine induced seizures. The clinical problems presented question the possibility that bipolar disorder; migraines and epilepsy may fall on the same spectrum of disorders. This could contribute towards the complexities in treating his conditions. Further insight into their link and interactions would facilitate diagnoses of these conditions, as well as improve treatment strategies when they are presented co-morbidly.

Anatomically dependent anticonvulsant properties of temporally-coded electrical stimulation

In the PTZ animal model of epilepsy, electrical stimulation applied to the amygdaloid complex may result in either pro-convulsive or anticonvulsant effect, depending on the temporal pattern used (i.e. periodic-PS and non-periodic-NPS electrical stimulation). Our hypothesis is that the anatomical target is a determinant factor for the differential effect of temporally-coded patterns on seizure outcome. The threshold dose of PTZ to elicit forelimb clonus and generalized tonic-clonic seizure behavior was measured. The effect of amygdaloid complex PS on forelimb clonus threshold showed a pro-convulsive effect while NPS was anticonvulsant. NPS also significantly increased generalized tonic-clonic threshold; while PS, although at lower threshold levels, did not present statistical significance. Thalamus stimulation did not affect forelimb clonus threshold and showed similar anticonvulsant profiles for both PS and NPS on generalized tonic-clonic threshold. In summary, the anatomical target is a determinant factor on whether temporally-coded ES differentially modulates seizure outcome.

Zolpidem dependence and withdrawal seizure--report of two cases

Zolpidem is a non-benzodiazepine property which binds selectively to the ?1-GABAA receptors, and has been widely prescribed to patients suffering from insomnia. We report two cases of zolpidem dependence with withdrawal seizure in the Asian population. The first case is a 43-year-old woman who took zolpidem up to the dosage of 200 to 400 mg per night. The second case is a 35-year-old woman who even began to take zolpidem every 15 to 30 minutes to get euphoric and relaxed, and she gradually increased the dosage to 400 to 500mg per day. After abrupt discontinuation of zolpidem, both cases immediately developed anxiety, global insomnia, restlessness, and tonic seizure. The purpose of this case report is to suggest that clinicians should pay close attention to the potential of zolpidem tolerance, abuse and dependence. The possibility of withdrawal seizure cannot be excluded especially at high doses.

[Cerebral complications induced by neurotoxity of nonionic contrast medium after embolization of unruptured cerebral aneurysms: report of 2 cases]

We successfully performed endovascular coil embolization for 2 patients with unruptured saccular aneurysms. However, transient cortical blindness and generalized seizure associated with CNS neurotoxity of contrast medium were noted for each patient after the procedure. In the first case of a 62-year-old woman with a right BA-SCA aneurysm, she complained of blindness with restlessness one day after the intervention but no evidence of embolism on MRA. Abnormal EEG with slow, large amplitudes and 99mTc-HMPAO SPECT-evidenced hyperperfusion were observed in the occipital area. Accompanied by resolution of the edematous changes on MRI in conjunction with normalization of EEG and rCBF by anticonvulsant administration, her visual acuity completely recovered 8 days after the onset. According to these findings, we considered this case as transient cortical blindness. In the second case of a 68-year-old man with a left MCA aneurysm, he exhibited generalized seizure 8 hours after the procedure. CT scan revealed retention of the contrast medium over the left hemisphere. Postictal EEG one day after the seizure showed left frontal slowing but had no evidence of contrast medium retention or hyperperfusion. He recovered well with corticosteroid, anticonvulsant, and intravenous hydration. His follow-up DSA 2 years after the coiling was performed without trouble by reducing the amount/concentration of the contrast medium and by prophylactic steroid and hydration. Non-ionic contrast medium-related neurotoxity as represented by transient cortical blindness or generalized seizure should be recognized as a possible complication of endovascular surgery where patients' brain areas are locally vulnerable to contrast medium exposure.

Antidepressant-associated myoclonic status in a patient with symptomatic generalized epilepsy: does risk occur with therapeutic doses?

The clinical and EEG data of a 49-year-old man with myoclonic and generalized tonic-clonic seizures resulting from early childhood encephalitis are described. He experienced no tonic-clonic seizure for 10 years before brief exposure first to 60 mg/day duloxetine and then to 20mg/day paroxetine for depressive symptoms. These drugs were separately prescribed at a 9-month interval, and after beginning each drug, the patient experienced tonic-clonic seizures of worsening intensity and myoclonus of increasing frequency. Clinical features correlated with subcontinuous, generalized spike-wave discharges on the EEG. Discontinuation of antidepressant treatment resulted in rapid disappearance of clinical and electrophysiological manifestations of myoclonic status. We suggest care must be taken when using serotonin-noradrenaline reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs), as these drugs pose the risk of complications in the specific population of people with myoclonic seizures.

Unintentional rapid opioid detoxification: case report

BACKGROUND

Naltrexone is a competitive opioid antagonist and is often used to maintain abstinence in detoxified opioid dependent patients. However, it can precipitate an accelerated withdrawal when ingested by an individual with concurrent opioid use.

METHODS

We report the case of a 28 year old male with opioid dependence syndrome presenting with chaotic symptoms following ingestion of naltrexone. Symptomatology, management is described and literature in this area is reviewed.

RESULTS

Accidental or surreptitious ingestion of naltrexone in a patient with concurrent opioid use can precipitate symptoms typical of opioid withdrawal in addition to other varying symptomatology. Most cases would require sedation and management of concurrent vomiting and diarrhoea.

CONCLUSIONS

Clinicians, especially those providing substance abuse and emergency care, need to be aware of the possibility of an accelerated and possibly life threatening withdrawal associated with naltrexone ingestion in an incompletely detoxified patient with opioid dependence.

[Epileptic seizures in critically ill patients]

THE AIM OF THIS ARTICLE: To review the causes, clinical signs, pathophysiology, consequences, and treatment of seizures and status epilepticus in critically ill patients. Only 25% of people, who have seizures and status epilepticus, have epilepsy as well. In the intensive care settings, seizures and status epilepticus are a common neurologic complication, which is attributable to primary neurologic pathology (stroke, hemorrhage, tumor, central nervous system infection, head trauma) or secondary to critical illness (anoxic brain damage, intoxications, metabolic abnormalities) and clinical management. There are three main subtypes of status epilepticus in intensive care units: generalized convulsive status epilepticus, focal motor status epilepticus, and nonconvulsive status epilepticus. A seizure is a consequence of electrical neurological derangement because of sudden imbalance between the inhibitory and excitatory forces within the network of cortical neurons. The main inhibiting neurotransmitter in the brain is gamma-aminobutyric acid (GABA), which binds to GABA-A and GABA-B receptors. The main excitatory neurotransmitter is glutamate, which binds to N-methyl-D-aspartate receptors. Different ions (Cl(-), K(+), Na(+), Ca(2+)) also play a role in the pathophysiology of seizures. Prolonged status epilepticus may lead to different systemic and neurologic consequences. Generalized convulsive status epilepticus is one of the most common emergencies encountered in clinical practice, which requires immediate treatment. The first-line drugs are benzodiazepines (lorazepam, diazepam), the second-line ones - phenytoin and fosphenytoin. For the treatment of refractory status epilepticus, barbiturates (phenobarbital, pentobarbital, thiopental), valproate, midazolam, propofol, and isoflurane are used. The dosage of drugs and parameters to monitor are referred in the article. The mortality from generalized convulsive status epilepticus is 15-50%; the main factors, influencing prognosis, are the cause and the duration of status epilepticus and age of a patient.

Severe Reversible Toxic Encephalopathy Induced by Cisplatin in a Patient with Cervical Carcinoma Receiving Combined Radiochemotherapy

CASE REPORT

A 45-year-old patient with cervix carcinoma received combined radiochemotherapy including cisplatin. After a cumulative dose of 240 mg/m(2) the patient suddenly became somnolent and developed a severe tetraparesis and generalized seizures. After ruling out intracranial bleeding, cerebral metastases as well as infectious and metabolic causes of this condition, a severe toxic encephalopathy was diagnosed based on the clinical findings and MRI scans. After symptomatic treatment on the intensive care unit all symptoms were completely reversible.

CONCLUSION

Toxic encephalopathy is a rare but dramatic complication of various cytostatic drugs. With the widespread use of cisplatin this rare disorder should be kept in mind.

Monitoring of acute generalized status epilepticus using multilocal diffusion MR imaging: early prediction of regional neuronal damage

BACKGROUND AND PURPOSE

Diffusion-weighted MR imaging (DWI) has emerged as tool for noninvasive and early detection of neuronal alterations. The aim of this study was to investigate the evolution of acute phase changes in different brain regions during experimental status epilepticus (SE) using DWI correlated with SE-induced neuronal cell loss.

METHODS

DWI was performed in 20 rats before (baseline) and 3, 5, 10, 15, 20, 30, 45, 60, 90, and 120 minutes after onset of pilocarpine-induced SE. Apparent diffusion coefficients (ADCs) were calculated for the parietal cortex, temporal cortex, pyriform cortex, hippocampus, amygdala, and thalamus and compared with baseline. Neuronal cell loss was quantified at different time points after SE using cresyl-violet-staining.

RESULTS

ADC-mapping demonstrated a significant transient increase in ADC (to 116 +/- 4% of baseline) in the very acute phase, starting 3 minutes after SE onset, lasting for 10 minutes, followed by a significant gradual decline in ADC in all animals. Compared with surviving animals (76 +/- 7%), decline in ADC was significantly lower for the animals who died within 2 hours for all regions of interest (63 +/- 6.5%, 0.45 +/- 0.03 x 10(-3) mm(2)/s) except the thalamus (P < .01, analysis of variance). There was good correlation between neuronal cell loss in specific brain regions 2 weeks after SE and maximal decrease in ADC (r > 0.76).

CONCLUSION

Serial ultrafast DWI is a sensitive noninvasive technique for early detection and monitoring of seizure-induced neuronal alterations. Using ADC-mapping differentiation of regional severity of neuronal damage may be possible because there is good correlation between the maximal decrease in ADC in the acute phase of SE and late neuronal cell loss.

Myoclonic-astatic epilepsy in a child with Sturge-Weber syndrome

A child with Sturge-Weber syndrome and a left occipital leptomeningeal angioma developed focal seizures at 6 years of age that responded initially to oxcarbazepine. After 7 months of seizure freedom, the patient developed typical myoclonic-astatic seizures associated with generalized electrographic discharges, which worsened as oxcarbazepine was increased. The seizures and electroencephalogram improved dramatically in 3 weeks as the oxcarbazepine was withdrawn and valproic acid was initiated. This case demonstrates the importance of recognizing that children with epilepsy due to focal lesions can develop secondary bilateral synchrony that can be aggravated by medications that are effective for partial seizures. In such cases, treatment with a broad-spectrum antiepileptic may be advantageous.

Series of seizures as a sign of development of recurrent malignant neuroleptic syndrome - a case report

Neuroleptic malignant syndrome (NMS) is an uncommon but sometimes fatal complication of neuroleptics and other medications that involve the central dopaminergic system. Many diagnostic criteria have been proposed for NMS but because of its variable presentation, universal criteria have not been established yet. Hyperthermia, disturbances of consciousness, extrapyramidal and autonomic symptoms are common features of NMS. We report the case of a 36 years old woman suffering from chronic schizophrenia and treated with flufenazine and olanzapine, who presented with series of generalised tonic-clonic seizures as the acute onset of recurrent malignant neuroleptic syndrome. Although atypical neuroleptics were previously thought to have less risk for MNS, combination of conventional and atypical neuroleptics in therapy increases the risk of NMS development and olanzapine might be responsible for the epileptic manifestations at the onset of fulminant NMS.

Tonic facilitation of glutamate release by presynaptic NR2B-containing NMDA receptors is increased in the entorhinal cortex of chronically epileptic rats

We have shown previously that when postsynaptic NMDA receptors are blocked, the frequency, but not amplitude, of spontaneous EPSCs (sEPSCs) at synapses in the entorhinal cortex is reduced by NMDA receptor antagonists, demonstrating that glutamate release is tonically facilitated by presynaptic NMDA autoreceptors. In the present study, we recorded sEPSCs using whole-cell voltage clamp in neurons in layer V in slices of the rat entorhinal cortex. Using specific antagonists for NR2A [(R)-[(S)-1-(4-bromo-phenyl)-ethylamino]-(2,3-dioxo-1,2,3,4-tetrahydroquinoxalin-5-yl)-methyl]-phosphonic acid] and NR2B [(alphaR, betaS)-alpha-(4-hydroxyphenyl)-beta-methyl-4-(phenylmethyl)-1-piperidinepropanol hydrochloride (Ro 25-6981)] subunit-containing receptors, we confirmed that in slices from juvenile rats (4-6 weeks of age), the autoreceptor is predominantly of the NR1-NR2B subtype. In older (4-6 months of age) control animals, the effect of the NR2B antagonist was less marked, suggesting a decline in autoreceptor function with development. In slices from rats (aged 4-6 months) exhibiting spontaneous recurrent seizures induced with a lithium-pilocarpine protocol, Ro 25-6981 again robustly reduced sEPSC frequency. The effect was equal to or greater than that seen in the juvenile slices and much more pronounced than that seen in the age-matched control animals. In all three groups, the NR2A antagonist was without effect on sEPSCs. These results suggest that there is a developmental decrease in NMDA autoreceptor function, which is reversed in a chronic epileptic condition. The enhanced autoreceptor function may contribute to seizure susceptibility and epileptogenesis in temporal lobe structures.

Anticonvulsant effect of amiloride in pentetrazole-induced status epilepticus in mice

Inhibition of sodium hydrogen exchangers (NHE) has been shown to diminish seizure activity in various in vitro and in vivo models of epilepsy. In the present study, we examined the effect of amiloride, a sodium hydrogen exchanger inhibitor, against pentetrazole (PTZ)-induced status epilepticus (SE). The study was conducted in mice and status epilepticus was induced by administering ip 50 mg/kg of phenytoin followed 2 hour later by PTZ, 100 mg/kg sc. Amiloride produced dose-dependent protection against PTZ-induced SE.

Action of two neuroactive steroids against motor seizures induced by pentetrazol in rats during ontogeny

The anticonvulsant action of two neuroactive steroids, 3alpha-hydroxy-5beta-pregnan-20-one (pregnanolone) and triethylammonium 3 alpha-hydroxy-20-oxo-5 alpha-pregnan-21-yl hydrogensuccinate (THDOC-conjugate), was tested against motor seizures induced by pentetrazol in immature rats. Five age groups (7, 12, 18 and 25 days old and adult rats) were pretreated with the steroids in doses from 2.5 to 40 mg/kg i.p. Twenty minutes later pentetrazol (100 mg/kg s.c.) was administered. Minimal seizures (clonic seizures of head and forelimb muscles with preserved righting ability) could be induced in the three older age groups. They were suppressed by pregnanolone in all these tested groups (this effect was best expressed in 18-day-old rats and decreased with age), whereas significant changes in THDOC-conjugate-pretreated animals appeared only in 18-day-old rats. Generalized tonic-clonic seizures were suppressed by both neuroactive steroids in all age groups, this effect being more marked with pregnanolone and again decreased with age. The 7- and 12-day-old rats exhibited higher sensitivity of the tonic phase so that generalized clonic seizures were observed. Duration of the effect was studied in 12- and 25-day-old animals; it was substantially shorter in the older rats than in 12-day-old animals. Both drugs exhibited an anticonvulsant action in developing rats but, unfortunately, their effect was only shortlasting.

Cellular and network mechanisms of spike-wave seizures

Spike-wave seizures are often considered a relatively "pure" form of epilepsy, with a uniform defect present in all patients and involvement of the whole brain homogeneously. Here, we present evidence against these common misconceptions. Rather than a uniform disorder, spike-wave rhythms arise from the normal inherent network properties of brain excitatory and inhibitory circuits, where they can be provoked by many different insults in several different brain networks. Here we discuss several different cellular and molecular mechanisms that may contribute to the generation of spike-wave seizures, particularly in idiopathic generalized epilepsy. In addition, we discuss growing evidence that electrical, neuroimaging, and molecular changes in spike-wave seizures do not involve the entire brain homogeneously. Rather, spike-wave discharges occur selectively in some thalamocortical networks, while sparing others. It is hoped that improved understanding of the heterogeneous defects and selective brain regions involved will ultimately lead to more effective treatments for spike-wave seizures.

Seizure Aggravation in Idiopathic Generalized Epilepsies

Seizures in the idiopathic generalized epilepsies (IGEs) usually remit completely with antiepileptic drugs (AEDs). Occasionally, however, they may be aggravated by AEDs. Before attributing exacerbation of seizures to an AED, alternative explanations need to be excluded. These include natural fluctuation of seizures, irregular compliance, maladjustment to the disease, comorbid illness, and development of tolerance. Aggravation may be due to a paradoxical reaction or drug-induced encephalopathy, sedative effects, or inappropriate use of a drug; and this need to be established, as it will guide management. An important caveat is that most data on aggravation of generalized seizures are based on anecdotal case reports or case series. Whether considering efficacy or aggravation, the interpretation of data from uncontrolled studies and case reports must be treated with caution. In practice, despite the fact that clear evidence is lacking, the possibility of seizure aggravation must be considered when treating people with IGEs. Predictive factors for seizure aggravation in a particular patient with a specific drug are yet to be fully defined. It is paramount to classify seizure type correctly in all patients. If this is not possible, a broad-spectrum AED should be used. Drugs that modulate Na+-channels and GABAergic drugs seem to be more prone to aggravating seizures, and therefore are best avoided in the initial management of IGE. Further studies are required to elucidate this phenomenon in full. It is interesting to speculate that paradoxical responses to AEDs may have pharmacogenetic value, serving as tools for a more precise and useful characterization of the epilepsies.

Antiepileptic effects of botulinum neurotoxin E

Experimental studies suggest that the delivery of antiepileptic agents into the seizure focus might be of potential utility for the treatment of focal-onset epilepsies. Botulinum neurotoxin E (BoNT/E) causes a prolonged inhibition of neurotransmitter release after its specific cleavage of the synaptic protein synaptosomal-associated protein of 25 kDa (SNAP-25). Here, we show that BoNT/E injected into the rat hippocampus inhibits glutamate release and blocks spike activity of pyramidal neurons. BoNT/E effects persist for at least 3 weeks, as determined by immunodetection of cleaved SNAP-25 and loss of intact SNAP-25. The delivery of BoNT/E to the rat hippocampus dramatically reduces both focal and generalized kainic acid-induced seizures as documented by behavioral and electrographic analysis. BoNT/E treatment also prevents neuronal loss and long-term cognitive deficits associated with kainic acid seizures. Moreover, BoNT/E-injected rats require 50% more electrical stimulations to reach stage 5 of kindling, thus indicating a delayed epileptogenesis. We conclude that BoNT/E delivery to the hippocampus is both antiictal and antiepileptogenic in experimental models of epilepsy.

Epilepsy and intrathecal baclofen therapy in children with cerebral palsy

The objective of this study was to analyze the relationship between epilepsy and intrathecal baclofen by investigating a consecutive sample of 150 children with cerebral palsy or spasticity of cerebral origin who underwent intrathecal baclofen. The medical charts of the 150 children were retrospectively reviewed. A series of 100 children with cerebral palsy, operated on other procedures, was reviewed as a control group. Forty percent of the 150 children had epilepsy before intrathecal baclofen pump implantation; 13.3% had a decrease in seizure frequency after intrathecal baclofen, while two children worsened and one child had seizures ex novo. We conclude that in children with spasticity of cerebral origin, intrathecal baclofen does not seem to aggravate or induce seizure activity.

Clinical experience with levetiracetam in childhood epilepsy: an add-on and mono-therapy trial

We examined the efficacy, optimum dosage and adverse effects of levetiracetam in two prospective trials in children with epilepsy. In the add-on trial, 67 children between 6 months and 16 years were included. In the mono-therapy trial, 10 children between 4 years and 16 years were included. Levetiracetam was titrated up to an optimal dosage for every individual patient, depending on efficacy and tolerability, and reflecting clinical practice. The range of dosages used was between 12 and 62 mg/kg/day, with a median of 33 mg/kg/day. Overall, 20 weeks after the start of levetiracetam, there was a median seizure reduction of 60% (add-on trial 50%; mono-therapy trial 81%). Levetiracetam was equally effective for partial and generalized seizures. Side effects were less common in the mono-therapy trial. Tiredness (7.8%) and aggressiveness (5%) were the most common side effects, and were dose-related, but were no reason to discontinue levetiracetam. In 25% of the children, a positive effect was seen on behaviour and/or alertness. This could not be related directly to seizure control. Overall, these two clinical trials confirm that levetiracetam is a broad spectrum anti-epileptic drug with a favourable safety profile. The positive effect on behaviour needs further quantitative study.

In vivo imaging of dendritic spines during electrographic seizures

Epilepsy is associated with significant neurological morbidity, including learning disabilities, motor deficits, and behavioral problems. Although the causes of neurological dysfunction in epilepsy are multifactorial, accumulating evidence indicates that seizures in themselves may directly cause brain injury. Although it is clear that seizures can result in neuronal death, it is likely that under some circumstances seizures can induce more subtle functional or structural alterations in neurons. We induced focal neocortical seizures with 4-aminopyridine in transgenic mice expressing green fluorescent protein in cortical neurons and sequentially imaged individual dendrites in living animals with two-photon laser-scanning microscopy to determine whether these seizures caused acute alterations in dendritic spine morphology. No dendritic alterations were observed in anesthetized animals during electrographic seizures over a 3-hour period. Similarly, in unanesthetized mice, low-stage, clinical electrographic seizures had minimal effect on dendritic spines. More severe, high-stage seizures in unanesthetized mice were associated with a moderate loss of spines and dendritic swelling, but this effect may have been contingent on a synergistic action of phototoxicity from the imaging method itself. Overall, our results suggest that most neocortical seizures have minimal acute effects on dendrites over several hours, but may predispose to dendritic injury under extreme conditions.

[Zidovudine-associated mitochondriopathy: three possible observations in Abidjan, Côte d'Ivoire]

In Africa, prevention of mother-to-child transmission of HIV (PMTCT) with antiretrovirals is becoming a key component of the response to the pandemic. Toxicity issues remain however a concern and require careful monitoring. We report here three observations of mild neurological deterioration among children for whom a diagnosis of mitochondrial dysfunction was considered possible. These children were identified within a PMTCT research program (ANRS 049) conducted in Abidjan, Côte d'Ivoire, and evaluating a short regimen of maternal zidovudine monotherapy for PMTCT of HIV type 1. Maternal HIV-1 infection was diagnosed during pregnancy before enrolment in the randomised trial (two cases) or in the subsequent open cohort (one case). These three women had been allocated to the ZDV group and had no particular medical history. Pregnancy check-up was negative except the diagnosis of HIV-1 infection. The three children were diagnosed as uninfected by HIV-1. Symptoms developed by the age of six months (two cases) and 13 months (one case): growth failure, anthropometric abnormalities, impaired psycho-motor development, generalised and repeated seizures. The evolution of these three HIV-uninfected children was favourable after 12 to 18 months. The transient nature of these abnormalities is compatible with mild complications of mitochondrial dysfunction. We conclude however that the anticipated benefits of PMTCT with antiretrovirals in Africa greatly outweigh the potential risks and should not lead to reconsider their public health interest

MPEP, an antagonist of metabotropic glutamate receptors, exhibits anticonvulsant action in immature rats without a serious impairment of motor performance

An antagonist of type I metabotropic glutamate receptors MPEP was found to exhibit anticonvulsant action in adult rodents. Present experiments were focused on action of this drug against pentetrazol-induced motor seizures in immature rats 12-, 18- and 25-days old. Dose of pentetrazol (100 mg/kg s.c.) was chosen to elicit minimal clonic seizures and (after a longer latency) generalized tonic-clonic seizures. Pretreatment with MPEP (doses from 10 to 80 mg/kg i.p.) resulted in a dose-dependent suppression of the tonic phase of generalized tonic-clonic seizures in all age groups studied. Efficacy of MPEP was higher and the effect lasted longer in 12- than in 25-day-old rats. In addition, minimal clonic seizures were suppressed in 18-day-old rats. Motor abilities of immature animals were not compromised by MPEP in doses of 20 and/or 40 mg/kg i.p., only righting reflex was a little slowed down in 12- and 18-day-old rats. In contrast to antagonists of ionotropic glutamate receptors anticonvulsant doses of MPEP do not induce unwanted side effects in motor performance of developing rats.

Worsening of Seizures by Oxcarbazepine in Juvenile Idiopathic Generalized Epilepsies

PURPOSE

Several studies have shown that carbamazepine (CBZ) may aggravate idiopathic generalized epilepsy (IGE). Oxcarbazepine (OXC) is a new drug chemically related to CBZ. We report six cases of juvenile IGE with a clear aggravation by OXC.

METHODS

We retrospectively studied all patients with IGE first referred to our epilepsy department between January 2001 and June 2003 and treated with OXC.

RESULTS

During this period, six patients were identified. All had an aggravation of their epilepsy in both clinical and EEG activities. OXC had been used because of an incorrect diagnosis of focal epilepsy or generalized tonic-clonic seizures (GTCSs) of undetermined origin (no syndromic classification of the epilepsy). Before OXC, only one patient had experienced a worsening of seizures with an inadequate drug (CBZ). Four had juvenile myoclonic epilepsy, one had juvenile absence epilepsy, and one had IGE that could not be classified into a precise syndrome. OXC (dosage range, 300-1,200 mg/day) was used in monotherapy in all of them except for one patient. Aggravation consisted of a clear aggravation of myoclonic jerks (five cases) or de novo myoclonic jerks (one case). Three patients had exacerbation of absence seizures. One patient had worsened dramatically and had absence status, and one had de novo absences after OXC treatment. The effects of OXC on GTCSs were less dramatic, with no worsening in frequency in three and a slight increase in three.

CONCLUSIONS

OXC can be added to the list of antiepileptic drugs that can exacerbate myoclonic and absence seizures in IGE.

Severe hyperphosphatemia and hypocalcemia following the rectal administration of a phosphate-containing Fleet pediatric enema

BACKGROUND

Toxicity secondary to rectally administered hypertonic phosphate solution in patients with normal renal function is rarely reported in the literature. We report a case of electrolyte disturbance and seizure secondary to the rectal administration of 2 Fleet pediatric enemas.

CASE REPORT

A 4-year-old white female with spinal muscular atrophy and chronic constipation was brought to the emergency department with complaints of lethargy and difficulty breathing following the administration of 2 Fleet pediatric enemas. In the emergency department, physical examination was significant for a depressed level of consciousness and shallow respirations. A basic metabolic profile was significant for a calcium of 3.3 mg/dL, phosphate of 23 mg/dL, and sodium of 153 mEq/L. Arterial blood gases revealed a pH of 7.24, Pco2 of 38 mm Hg, Po2 of 220 mm Hg. Electrocardiogram revealed a prolonged QT interval of 340 milliseconds with a corrected QT interval of 498 milliseconds. Sixteen hours postexposure, she experienced a generalized seizure unresponsive to multiple doses of lorazepam and responsive only to 100 mg of intravenous calcium chloride. Two days after presentation, the patient experienced complete resolution of symptoms.

CONCLUSION

Osmotically acting hypertonic phosphate enemas can result in severe toxicity if retained. This is true even in patients without predisposing risk factors.

[Refractory generalized convulsions in a patient undergoing brain tumor resection during propofol anesthesia]

Propofol has been used to treat convulsions, while the drug is known to induce convulsions. We described a case of generalized convulsions during brain tumor resection under propofol anesthesia. A 24-year-old man was scheduled to undergo brain tumor resection. He had no history of epilepsy. Anesthesia was induced and maintained with propofol and fentanyl. During the craniotomy, the patient developed generalized convulsions. Diazepam, thiamylal, and phenytoin were given intravenously and the seizure activity resolved. Generalized convulsions recurred three times during the operation. Postoperative course was uneventful. On the 16 th postoperative day, the patient underwent ventriculoperitoneal shunt under general anesthesia using sevoflurane, nitrous oxide and oxygen. Convulsions were not noted intra- and postoperatively. Because convulsions did not occur during sevoflurane anesthesia and the patient had no history of epilepsy, propofol may have induced a generalized convulsions on the first operation.

Cyclosporin A-associated status epilepticus related to hematopoietic stem cell transplantation for thalassemia

Cyclosporin A is an essential drug for graft versus host disease (GvHD) prophylaxis in allogeneic hematopoietic stem cell transplantation. Cyclosporin A-associated neurotoxicity is common but poorly understood. The authors herein report on 3 patients receiving transplants for thalassemia. GvHD prophylaxis included cyclosporin A, prednisolone, and methotrexate. All patients developed a status epilepticus with cortical signal alterations located mainly in occipital regions on T2-weighted magnetic resonance imaging. Complete disappearance of the neurologic symptoms and radiographic findings was observed without discontinuing cyclosporin A therapy. Especially, pediatric thalassemics receiving busulfan/cyclophosphamide as preparative regimen seem to be significantly prone to cyclosporin A-associated seizures.

Right-sided vagus nerve stimulation reduces generalized seizure severity in rats as effectively as left-sided

As currently utilized, vagus nerve stimulation (VNS) is applied to the cervical trunk of the left vagus nerve to suppress seizures clinically. Demonstration that VNS can also reduce seizure severity when electrodes are placed on the right cervical vagus nerve in rats would provide empirical evidence that the antiepileptic effects of VNS are not an exclusive property of the left vagus nerve. Rats were implanted with a custom cuff electrode on either the left or right cervical vagus nerve. Two days later, continuous VNS was begun in half the rats with left-sided and half with right-sided electrodes. The remaining rats were connected to the stimulator, but did not receive VNS. After 30s, pentylenetetrazole (PTZ) was administered systemically and seizures were rated by a blinded observer. The PTZ test was repeated two days later, with VNS administered to the previously unstimulated rats, while the others received no stimulation. VNS significantly reduced the severity of PTZ-induced seizures in rats regardless of the side of stimulation as compared to their no-VNS (control condition) seizure severity. No significant differences in efficacy existed based on the side of stimulation. These results indicate that right-sided VNS in rats is just as effective as left-sided VNS, suggesting that fibers necessary for seizure suppression are not unique to the left vagus nerve.

Diazepam terminates brief but not prolonged seizures in young, naïve rats

PURPOSE

Ample evidence exists from both clinical and animal studies that the success of benzodiazepine intervention during status epilepticus (SE) in the mature nervous system is inversely related to seizure duration. This relationship has not been well studied in the developing nervous system.

METHODS

The objective of this study was to investigate the relation of age and success of diazepam (DZP) treatment in the lithium-pilocarpine model of secondarily generalized seizure in the rat by using naïve rats of three age groups, roughly corresponding to the human ages of infancy (P15), adolescence (P20), and adult (P60).

RESULTS

In all age groups, the dosage of DZP that stopped the seizures at 5 min was not effective in terminating seizures at 60 min. This decline in efficacy was present as early as 15 min after seizure onset.

CONCLUSIONS

These findings demonstrate that the inverse relation between the success of benzodiazepine intervention and seizure duration is observed in young as well as in adult rats and provide further evidence that intervention for SE should commence early.

[A young patient of acute encephalitis complicated with acyclovir encephalopathy without renal dysfunction]

A previously healthy 30-year-old woman was admitted to our hospital because of impaired consciousness after convulsion. A temporary diagnosis of herpes simplex encephalitis was made, and intravenous acyclovir (ACV) therapy (250 mg four times daily in normal saline over 2 hours) was started. Three days later, she became confused, and was having hallucinations, dysarthria and generalized painful seizures occurred without focal neurologic deficit. Whether the neuropsychiatric symptoms were related to herpes simplex encephalitis or acyclovir neurotoxity was initially unclear. The brain MRI and lumbar puncture findings were initially normal, but abnormal FLAIR lesions appeared later. ACV-associated encephalopathy was considered. ACV was discontinued, and she recovered from the neurological disorder within 24 hours. Although blood levels of acyclovir were not determined, it is unlikely that they were in a toxic range, in view of her normal renal function.

Chronic management of seizures in the syndromes of idiopathic generalized epilepsy

As a group, idiopathic generalized epilepsies (IGEs) have the highest rates of complete seizure control with medication. However, there are little evidence-based data to guide drug choice for treatment. Examples of IGE include absence epilepsy, generalized tonic-clonic epilepsy, and juvenile myoclonic epilepsy. Generalized epilepsies seem to be particularly vulnerable to seizure aggravation, and medications that are primarily effective against partial seizures are more commonly involved in seizure aggravation than other medications. A review of current research has shown that only a few medications can control IGE without potentially causing seizure aggravation. Broad-spectrum antiepileptic drugs such as valproate (VPA), lamotrigine, and topiramate are extremely effective at controlling a variety of seizures without causing excessive seizure aggravation. Among these drugs, VPA has the longest clinical experience history and the largest body of published data.

Does vigabatrin possess an anticonvulsant action against pentylenetetrazol-induced seizures in developing rats?

Anticonvulsant action of vigabatrin (300, 600, 900 and/or 1200 mg/kg i.p.), an inhibitor of GABA-transaminase, was studied in a model of motor sezures elicited by pentylenetetrazol. Five age groups of rats (7, 12, 18, 25 and 90 days old) received a s.c. injection of pentylenetetrazol 4, 6 and/or 24 hours after vigabatrin administration. The incidence of minimal, predominantly clonic seizures was not changed in any age group, but their latencies were prolonged in 18- and 25-day-old rats. Generalized tonic-clonic seizures were influenced in a more complex manner. Incidence of these seizures was decreased in 7-day-old rat pups 24 hours after vigabatrin administration. Higher doses of vigabatrin exhibited a similar effect in adult rats at all intervals studied. Specific suppression or at least restriction of the tonic phase was observed in all groups of immature rats, the effect was more marked 24 hours after vigabatrin than at shorter intervals. The anticonvulsant action of vigabatrin, which could be demonstrated mainly against generalized tonic-clonic seizures, varies markedly during development.

Pentylenetetrazol-induced seizures in immature rats provoke long-term changes in adult hippocampal cholinergic excitability

PURPOSE

We previously demonstrated that the anticholinesterase eserine provokes interictal-like discharges in the CA3 area of hippocampal slices from rats in which generalized seizures had been induced by pentylenetetrazol (PTZ) when immature. In this study, we investigated several factors as the possible mechanism for this effect, including age at convulsions.

METHODS

Rats were injected with PTZ on postnatal day (P) 18-20 or >P60, and neuronal activity was recorded intra- and extracellularly from CA3 5-10 or >40 days later. In additional experiments, convulsions were triggered by kainate or were blocked by pentobarbital. Hippocampal (a) acetylcholine (ACh) innervation density was measured by immunocytochemistry, and ACh and gamma-aminobutyric acid (GABA) contents were determined by high-performance liquid chromatography (HPLC)-electrospray ionization.

RESULTS

The excitatory effect of eserine was the most consistent in slices from rats PTZ-treated when immature and after the long interval, whereas the reverse was true in rats treated as adults. This effect was dependent on the occurrence of a seizure and was less prevalent when the seizure had been provoked by kainate. Adult animals PTZ-treated at P20 did not differ from control in (a) poly- or monosynaptic GABAA and GABAB CA3 inhibitory postsynaptic potentials (IPSPs); (b) density of ACh innervation; or (c) tissue content of ACh and GABA.

CONCLUSIONS

A PTZ-induced generalized seizure in immature rat provokes endogenous ACh-induced interictal-like discharges in adult hippocampal CA3. This effect is only transiently observed if the seizure was induced in adult. It does not appear to be related to a change in GABAergic inhibition, in density of ACh innervation, or in ACh or GABA content.

Effects of pentylenetetrazole and 4-aminopyridine on the auditory brainstem response (ABR) and on the hearing sensitivity in the guinea pig in vivo

For exploring a possible connection between the reduced hearing sensitivity and certain abnormalities in the auditory brainstem responses (ABRs) in generalized epilepsy, the effects of two convulsing agents, namely pentylenetetrazole (PTZ) and of 4-aminopyridine (4-AP), on: (1). the cortical activity (EEG), (2). the hearing threshold and (3). the amplitudes and latencies of the ABR waves evoked by a stimulus of high intensity (100 dB) were investigated in guinea pigs. All animals injected (i.p.) with 100mg/kg PTZ or with 2mg/kg 4-AP developed generalized seizures, followed by characteristic EEG patterns for the post-ictal period, that were accompanied by a marked reduction of the hearing sensitivity (as indicated by the elevated threshold of the ABR), as well as by retro-cochlear changes (as judged by the changes in the later ABR waves in response to 100 dB). For instance, both convulsing agents decreased the amplitude and increased the latency of P4, that is the wave component of the ABRs generated in the lateral superior olivary nucleus and while PTZ increased the latency of P3, the wave component of the ABRs generated in the medial superior olivary nucleus, 4-AP dramatically increased its amplitude. Comparison of recordings taken at specific times for the duration of the post-ictal period (i.e. within about 1h for PTZ and 2h for 4-AP) reveals that the extent of the changes on the EEG matches with the increase in the auditory threshold and with the extent of the changes on the later waves of the ABR elicited by 100 dB. These data indicate that changes in the activity of the lateral and the medial nuclei of the superior olivary complex (SOC) accompany the hearing loss and the post-ictal epileptic cortical activity.

The effect of electrical stimulation of the subthalamic nucleus on seizures is frequency dependent

PURPOSE

Animal studies and anecdotal human case reports have indicated that the subthalamic nucleus (STN) may be a site of anticonvulsant action.

METHODS

We tested the hypothesis that continuous electrical stimulation of the STN inhibits seizures acutely. We determined the effects of three stimulation frequencies, 130 Hz, 260 Hz, and 800 Hz, on generalized clonic and tonic-clonic flurothyl seizures. Adult male rats were implanted with concentric bipolar stimulating electrodes in the STN bilaterally. After recovery, rats underwent flurothyl seizures to compare the effects of each stimulation frequency on seizure threshold. Rats were tested 4 times, twice in the stimulated condition, and twice in the unstimulated condition. The order of trials was random, except that stimulation trials alternated with control trials. Flurothyl seizure thresholds under each stimulation condition were compared with control values from the same animal.

RESULTS

Bilateral stimulation of the STN at 130 Hz produced a significant increase in the seizure threshold for clonic flurothyl seizures, whereas stimulation at 260 Hz did not appear to have any effect on seizures. STN stimulation at 800 Hz significantly lowered seizure threshold for tonic-clonic seizures.

CONCLUSIONS

We conclude that electrical stimulation of the STN can be anticonvulsant, but the effects appear to depend on the stimulation frequency and the type of seizure.

Seizures in a boy with subacute sclerosing panencephalitis during high-dose intrathecal interferon-alpha therapy

A 27-month-old boy was admitted with speech abnormality, inability to walk, and involuntary movements. He was diagnosed with subacute sclerosing panencephalitis based on clinical and laboratory findings. Inosiplex (100 mg/kg/day orally) plus intrathecal interferon-alpha (3 million units/dose twice per week) in a standard regime were given. After four doses of interferon it was prescribed as 6 million units/dose/week because he had been admitted from a remote district. One day after giving the second dose of 6 million units of interferon, two generalized tonic-clonic seizures that occurred within an hour, associated with high fever, which lasted approximately 5 minutes were observed. An antiepileptic agent was not administered because electroencephalogram results did not indicate epileptic discharges. After this condition we returned to the first treatment protocol of interferon (3 million units/dose twice per week). At the current time, he is in the fifth month of follow-up and remains convulsion-free. To the best of our knowledge, seizures as a result of high-dose intrathecal interferon in subacute sclerosing panencephalitis has not been reported in the literature. Our patient demonstrated that it is reasonable to avoid the use of high-dose intrathecal interferon-alpha in childhood.

Ifosfamide encephalopathy and nonconvulsive status epilepticus

BACKGROUND

Ifosfamide (IFX), an alkylating agent and isomer of cyclophosphamide, is used as a single agent or a component of multi-agent chemotherapy in the treatment of ovarian, testicular, head and neck cancers, sarcomas and lymphomas. Encephalopathy is manifested by cerebellar ataxia, confusional state, complex visual hallucinations, extrapyramidal signs, seizures, and mutism.

CASE REPORTS

We report two patients with non-Hodgkin's lymphoma presenting with mutism and confusional state after IFX infusion. Nonconvulsive status epilepticus (NCSE) as the cause of confusion was diagnosed on the basis of EEG pattern and the apparent improvement following intravenous administration of diazepam.

CONCLUSIONS

Electroencephalogram abnormalities during IFX treatment have been described but recordings are only available in six cases. In three of them, paroxysmal alterations warranted the diagnosis of NCSE; however, most cases of IFX encephalopathy might have associated NCSE.

Cyclosporin A-induced encephalopathy after allogeneic bone marrow transplantation with prevention of graft-versus-host disease by tacrolimus

A 21-year-old woman with severe aplastic anemia received an allogeneic bone marrow transplant (allo-BMT) from an HLA-matched and ABO-matched sibling donor after conditioning with cyclophosphamide, rabbit ATG (Lymphoglobuline; Aventis-Pharma), and total lymphoid irradiation. She had a long history of cyclosporin A (CsA) therapy before conditioning. She complained of severe headache and convulsions on day 0, and findings on magnetic resonance images suggested CsA-induced encephalopathy. CsA was immediately stopped, and tacrolimus for prevention of graft-versus-host disease (GVHD) was started on day 2. Hematological engraftment was observed on day 14 without serious GVHD. Prompt diagnosis, replacement of immunosuppressive agents, and careful monitoring of serum drug concentrations are thought to have contributed to the patient's good clinical course, since CsA-induced encephalopathy tends to be recurrent but to improve completely without any sequelae.

Anticonvulsant activities of the FS-1 subfraction isolated from roots of Delphinium denudatum

Delphinium denudatum Wall. (Ranunculaceae) is a medicinal herb used for the treatment of epilepsy in the subcontinent. The present study reports the anticonvulsant activities in the maximal electroshock test (MEST) and subcutaneous pentylenetetrazole (PTZ), bicuculline (BIC), picrotoxin (PIC)-induced seizures of the FS-1 subfraction (FS-1) that was obtained by purification of an aqueous fraction isolated from the roots of D. denudatum. In CF 1 mice, FS-1 (600 mg/kg i.p.) exhibited very potent anticonvulsant activity that was comparable to the effects of the well-known antiepileptic drug phenytoin (20 mg/kg) in MEST and protected 100% animals from hind limb tonic extension phase of this model. FS-1 also suppressed PTZ-induced threshold seizure and the loss of the righting reflex with tonic fore and hind limb extension by 100%, similar to the antiepileptic drug valproic acid (350 mg/kg). BIC-induced seizures were suppressed in 80% of the animals. FS-1 exhibited weak anticonvulsant effect on PIC-induced seizures, however, it significantly reduced mortality and delayed the onset of seizures. FS-1 had no effect on strychnine (STN)-induced extensor seizures. The results demonstrate the broad and potent anticonvulsant activity of the compounds in FS-1 of D. denudatum.