Treatment of infantile spasms: an evidence-based approach

Lissencephaly in an epilepsy cohort: Molecular, radiological and clinical aspects

INTRODUCTION

Lissencephaly is a rare malformation of cortical development due to abnormal transmantle migration resulting in absent or reduced gyration. The lissencephaly spectrum consists of agyria, pachygyria and subcortical band heterotopia. In this study we compared genetic aetiology, neuroradiology, clinical phenotype and response to antiepileptic drugs in patients with epilepsy and lissencephaly spectrum malformations.

METHODS

The study group consisted of 20 patients - 13 males and 7 females, aged 18 months to 21 years at the time of data collection. Genetic testing was performed by oligonucleotide array comparative genomic hybridization (microarray), multiplex ligation-dependent probe amplification (MLPA), targeted gene panels and whole exome/genome sequencing. All neuroradiological investigations were re-evaluated and the malformations were classified by the same neuroradiologist. Clinical features and response to anti-epileptic drugs (AEDs) were evaluated by retrospective review of medical records.

RESULTS

In eleven patients (55%) mutations in PAFAH1B1 (LIS1) or variable microdeletions of 17p13.3 including the PAFAH1B1 gene were detected. Four patients (20%) had tubulin encoding gene mutations (TUBA1A, TUBG1 and TUBGCP6). Mutations in DCX, DYNC1H1, ADGRG1 and WDR62 were identified in single patients. In one patient, a possibly pathogenic intragenic deletion in TRIO was detected. A clear radiologic distinction could be made between tubulinopathies and PAFAH1B1 related lissencephaly. The majority of the patients had therapy resistant epilepsy and epileptic spasms was the most prominent seizure type. The best therapeutic response to seizure control in our cohort was obtained by the ketogenic diet, vigabatrin, clobazam, phenobarbital and valproate.

CONCLUSION

The most common genetic aetiologies in our cohort of 20 individuals with epilepsy and lissencephaly spectrum were intragenic deletions or single nucleotide mutations in PAFAH1B1 or larger deletions in 17p13.3, encompassing PAFAH1B1, followed by mutations in tubulin encoding genes. Radiological findings could reliably predict molecular results only in agyria with a posterior to anterior gradient. Radiological and molecular findings did not correlate consistently with severity of clinical outcome or therapeutic response.

Evolution and course of early life developmental encephalopathic epilepsies: Focus on Lennox-Gastaut syndrome

OBJECTIVES

Developmental encephalopathic epilepsies (DEEs) are characterized by refractory seizures, disability, and early death. Opportunities to improve care and outcomes focus on West syndrome/infantile spasms (WS/IS). Lennox-Gastaut syndrome (LGS) is almost as common but receives little attention. We examined initial presentations of DEEs and their evolution over time to identify risk and indicators of developing LGS.

METHODS

Data are from the Connecticut Study of Epilepsy, a prospective, longitudinal study of 613 children with newly diagnosed epilepsy recruited in 1993-1997. Central review of medical records permitted classification of epilepsy syndromes at diagnosis and at reclassification 2, 5, and 9 years later. DEEs were compared to other epilepsies for seizure and cognitive outcomes and mortality. Analyses examined the evolution of DEE syndromes after initial presentation, with specific comparisons made between WS/IS and LGS. Statistical analyses were performed with t tests and chi-square tests.

RESULTS

Fifty-eight children (9.4%) had DEEs, median onset age = 1.1 years (interquartile range ([IQR] 0.3-1.3) in DEEs and 6.0 years (IQR 3.0-9.0) in other epilepsies (P < 0.001). DEEs vs other epilepsies had more pharmacoresistance (71% vs 18%), intellectual disability (84% vs 11%), and mortality (21% vs <1%; all P < 0.001). During follow-up, the form of epilepsy evolved in 33 children. WS/IS was the most common initial diagnosis (N = 23) and in 5 children WS/IS evolved later. LGS was diagnosed initially in 4 children (1 later revised) and in 22 by the end of follow-up, including 7 evolving from WS/IS and 12 from nonsyndromic generalized, focal, or undetermined epilepsies. Evolution to LGS took a median of 1.9 years. LGS developed in 13% of infants, including 9% of those who did not present initially with WS/IS.

SIGNIFICANCE

DEEs account for disproportionate amounts of pharmacoresistance, disability, and early mortality. LGS often has a window between initial presentation and full expression. LGS should become targeted for early detection and prevention.

Randomized, Single-Blind, Parallel Clinical Trial on Efficacy of Oral Prednisolone Versus Intramuscular Corticotropin: A 12-Month Assessment of Spasm Control in West Syndrome

OBJECTIVE

We earlier completed a single-blind, parallel-group, randomized clinical trial to test the null hypothesis that adrenocorticotropic hormone (ACTH) is not superior to high-dose prednisolone for short-term control of West syndrome. We now present long-term follow-up data for spasm control for individuals who completed this earlier trial.

METHODS

Infants with untreated West syndrome were randomized to receive 14 days of prednisolone (40 to 60 mg/day) or intramuscular long-acting ACTH (40 to 60 IU every other day). They were evaluated at three, six, and 12 months to evaluate long-term spasm control.

RESULTS

The total number of infants treated was 97 (48 prednisolone; 49 ACTH). All completed the treatment course. Eighty-five, 82, and 76 children were available for follow-up at three, six, and 12 months. The number lost to follow-up at each interval was not statistically different. Likelihood of spasm freedom at three months was significantly higher for prednisolone (64.6%) than for ACTH (38.8%) (P = 0.01; odds ratio = 2.9; 95% confidence interval = 1.3 to 6.6). At six months (P = 0.19) and twelve months (P = 0.13), the control of spasms was not statistically different, although a trend in favor of prednisolone was documented at both of these time points (58.3% versus 44.9% for ACTH at six months and 56.2% versus 40.8% with ACTH at 12 months). After initial remission by day 14 (n = 46), the likelihood of a relapse within the next 12 months was not statistically different between the two treatment groups (P = 0.1).

CONCLUSIONS

Control of spasms at three months was significantly better if initially treated with prednisolone. Control of spasms at six and 12 months was not significantly different despite a trend favoring prednisolone. Risk of relapse following initial remission was similar in the two groups.

The efficacy of moderate-to-high dose oral prednisolone versus low-to-moderate dose intramuscular corticotropin for improvement of hypsarrhythmia in West syndrome: a randomized, single-blind, parallel clinical trial

BACKGROUND

The role of therapy on improvement of hypsarrhythmia has not been systematically assessed. This study was performed to assess the efficacy of oral prednisolone and intramuscular adrenocorticotrophin hormone in improving hypsarrhythmia in West syndrome.

METHOD

Children (2 months-2 years), with previously untreated West syndrome, were randomized to receive 40-60 IU every other day of intramuscular adrenocorticotrophin hormone or 40-60 mg/day of oral prednisolone for 14 days. Children with tuberous sclerosis were excluded. Improvement of hypsarrhythmia was assessed blindly using a hypsarrhythmia severity scale before and after completion of therapy. Adverse effects were assessed on day 14 using symptom diary. (Clinical trial registry identifier: SLCTR/2010/010.)

RESULTS

From 92 newly diagnosed West syndrome infants, 48 were randomized to receive prednisolone and 44 to receive adrenocorticotrophin hormone. Eighty infants completed the posttreatment evaluation according to specifications. The hypsarrhythmia severity score, significantly improved with hormonal therapy for 2 weeks (10.45 ± 2.65 vs 3.45 ± 2.67); P < 0.01. When individual treatment arms were compared using mean differences in the improvement of scores, improvement in prednisolone arm (7.95 ± 2.76) was significantly greater than that in the adrenocorticotrophin hormone arm (6.00 ± 2.61); P < 0.01. Both forms of therapy were tolerated well. Frequent crying, irritability, weight gain, increased appetite, and abdominal distension were more common (but not statistically significant) with prednisolone.

CONCLUSIONS

Hypsarrhythmia severity score improved significantly with both hormonal therapies, but this improvement was significantly better with oral prednisolone than intramuscular adrenocorticotrophin hormone. This is the first ever documentation of a superior therapeutic role of oral steroids in West syndrome.

Intravenous methylprednisolone for intractable childhood epilepsy

BACKGROUND

Steroids have been used for the treatment of certain epilepsy types, such as infantile spasms; however, the use in the treatment of other intractable epilepsies has received limited study. We report our experience with intravenous methylprednisolone in children with epilepsy refractory to multiple antiepileptic drugs.

METHODS

A series of consecutive children were analyzed retrospectively. Patients with infantile spasms, progressive degenerative, or metabolic disorders were excluded.

RESULTS

Seventeen children aged 2-14 (mean 5.3) years were included. Associated cognitive and motor deficits were recognized in 82%. Most children (88%) had daily seizures and 13 (76%) were admitted previously with status epilepticus. The epilepsy was cryptogenic (unknown etiology) in 47% and the seizures were mixed in 41%. Intravenous methylprednisolone was given at 15 mg/kg per day followed by a weaning dose of oral prednisolone for 2-8 weeks (mean 3 weeks). Children were followed for 6-24 months (mean 18). Six (35%) children became completely seizure free; however, three of them later developed recurrent seizures. At 6 months posttreatment, improved seizure control was noted in 10 (59%) children. Children with mixed seizures were more likely to have a favorable response than those with one seizure type (49% vs 31%, P = 0.02). No major side effects were noted, and 35% of the parents reported improvements in their child's alertness and appetite.

CONCLUSION

Add-on steroid treatment for children with intractable epilepsy is safe and may be effective in some children when used in a short course.

Prenatal corticosteroids modify glutamatergic and GABAergic synapse genomic fabric: insights from a novel animal model of infantile spasms

Prenatal exposure to corticosteroids has long-term postnatal somatic and neurodevelopmental consequences. Animal studies indicate that corticosteroid exposure-associated alterations in the nervous system include hypothalamic function. Infants with infantile spasms, a devastating epileptic syndrome of infancy with characteristic spastic seizures, chaotic irregular waves on interictal electroencephalogram (hypsarhythmia) and mental deterioration, have decreased concentrations of adrenocorticotrophic hormone (ACTH) and cortisol in cerebrospinal fluid, strongly suggesting hypothalamic dysfunction. We have exploited this feature to develop a model of human infantile spasms by using repeated prenatal exposure to betamethasone and a postnatal trigger of developmentally relevant spasms with NMDA. The spasms triggered in prenatally primed rats are more severe compared to prenatally saline-injected ones and respond to ACTH, a treatment of choice for infantile spasms in humans. Using autoradiography and immunohistochemistry, we have identified a link between the spasms in our model and the hypothalamus, especially the arcuate nucleus. Transcriptomic analysis of the arcuate nucleus after prenatal priming with betamethasone but before trigger of spasms indicates that prenatal betamethasone exposure down-regulates genes encoding several important proteins participating in glutamatergic and GABAergic transmission. Interestingly, there were significant sex-specific alterations after prenatal betamethasone in synapse-related gene expression but no such sex differences were found in prenatally saline-injected controls. A pairwise relevance analysis revealed that, although the synapse gene expression in controls was independent of sex, these genes form topologically distinct gene fabrics in males and females and these fabrics are altered by betamethasone in a sex-specific manner. These findings may explain the sex differences with respect to both normal behaviour and the occurrence and severity of infantile spasms. Changes in transcript expression and their coordination may contribute to a molecular substrate of permanent neurodevelopmental changes (including infantile spasms) found after prenatal exposure to corticosteroids.

Burden of disease and unmet needs in tuberous sclerosis complex with neurological manifestations: systematic review

OBJECTIVES

Tuberous sclerosis complex (TSC) is a progressive genetic disorder characterized by pervasive benign tumor growth. We sought to assess the current understanding of burden of TSC-related neurological manifestations.

METHODS

We systematically searched MEDLINE- and EMBASE-indexed, English-language literature (5/2000-5/2010) and non-indexed materials.

RESULTS

In total, 119 articles were included, 115 on epidemiology and treatment. Recent prevalence estimates from Ireland and Taiwan report TSC in 1:14,000-25,000 individuals, below older estimates of 1:10,000. While neurological manifestations are common, treatment is largely unaddressed by guidelines and focuses on symptoms, with resection standard for subependymal giant cell astrocytomas (SEGAs) and common practice for refractory epilepsy. Antiepileptic drugs and mammalian target of rapamycin inhibitors safely, effectively minimize the need for surgery for severe epilepsy and SEGAs.

CONCLUSION

Morbidity and treatment burden of prevalent neurological manifestations is significant, suggesting substantial economic and humanistic burden; however, these areas are poorly studied, indicating total disease burden is unknown. Future research should assess quality of life, caregiver burden, and costs.

Treatment of West syndrome

West syndrome is one of the most refractory epileptic syndromes in infancy, and many researchers have made great effort to find optimal treatment modalities for this syndrome. In this review, previous literature on optimal treatments of West syndrome and its refractory nature were briefly presented, followed by an introduction of recent publication of expert opinions from the US and Europe. An Asian expert opinion generated by a short questionnaire survey was then presented. It was shown that medically proven optimal treatment of West syndrome is not always the practical treatment of choice in Asian countries. Cost and geographical regions should also be taken into account in making practical choices for treatment of West syndrome.

Major adverse events associated with treatment of infantile spasms

Few studies have focused on tolerability and adverse events associated with natural adrenocorticotropic hormone injections for treatment of infantile spasms. Using a retrospective chart review of 130 patients, the authors compare major adverse events, weight and blood pressure changes, and unplanned medication changes associated with adrenocorticotropic hormone (ACTH) injections versus other antiepileptic drugs. Children treated with adrenocorticotropic hormone injections experienced significant short-term weight gain and blood pressure elevations, which were readily reversible with weaning off the drug. Twenty-three percent of patients treated with adrenocorticotropic hormone (14 of 60) and 17% of patients treated with other antiepileptic drugs (11 of 65) experienced a major adverse event during treatment. Few patients overall required a change in medication due to intolerable side effects. Despite early changes in weight and blood pressure, short courses of high-dose natural adrenocorticotropic hormone are generally well tolerated with no increased major adverse events when compared to antiepileptic drugs in the treatment of infantile spasms.

What is epilepsy? Clinical perspectives in the diagnosis and treatment

SUMMARY

The CINNR International Conference, "An Overview of Epilepsy Research: What, Where, When, and Why?," was designed to introduce epilepsy to the nonclinician interested in epilepsy research. This article discusses the clinical aspects of epilepsy, defines clinical terms associated with epilepsy and seizure disorders, and outlines the scope of the clinical problem and the issues that need clarification from a clinical perspective. Most importantly, it is hoped that this article will put a human face on this common disease.

Antiepileptic drug treatment in children

Epilepsy is one of the most common neurological disorders of childhood, and antiepileptic drugs represent the main component of its treatment. The current emphasis in epilepsy treatment is to improve quality of life, not only by suppressing seizure, but also by minimizing the side effects of medications. The last 15 years have been characterized by significant advances in the development of new agents that have helped us to get closer to this goal. Knowledge of the essential properties, key indications and interactions of each antiepileptic drug will help to optimize efficacy and reduce adverse reactions. Age is also a determining factor of the epilepsy phenotype and its treatment. This review addresses the principles of pediatric epilepsy treatment, summarizes the profile of each of the commonly used antiepileptic drugs, and provides a treatment paradigm for particular seizures and epilepsy syndromes of childhood.

Vigabatrin

Refractory epilepsies such as infantile spasms (IS) and complex partial seizures (CPS) can have a severe negative impact on the neurological integrity and quality of life of affected patients, in addition to drastically increasing their risk of premature mortality. Early identification of potentially effective pharmacotherapy agents is important. Vigabatrin has been shown to be a generally well tolerated and effective antiepileptic drug (AED) in a wide variety of seizure types affecting both children and adults, particularly those with IS and CPS. A bilateral, concentric constriction of the peripheral visual field characterizes the visual field defect (VFD) associated with vigabatrin, well characterized by numerous studies. This peripheral VFD presents in 30-50% of patients with exposure of several years; however, most of these patients are asymptomatic. In well-controlled studies, the earliest onset in patients with CPS is 11 months and at 5 months in infants, with average onsets being more than 5 years and 1 year, respectively. Patients with a peripheral VFD retain an average 65 degrees of lateral vision (normal, 90 degrees). The fact that many patients never develop the vigabatrin-related peripheral VFD, despite long-term exposure at high doses, may support the hypothesis that the injury is an idiosyncratic adverse drug reaction (as opposed to a strict dose- or duration-dependent toxicity). Effective testing methods are available to aid in the early detection and management of the peripheral VFD. This article discusses issues of importance to clinical decision-making in the use of vigabatrin to assist the physician and patient in assessing the benefits of vigabatrin therapy and understanding the potential risks of the VFD and uncontrolled seizures.

A pharmacogenetic exploration of vigabatrin-induced visual field constriction

INTRODUCTION

Use of the antiepileptic drug (AED) vigabatrin is severely limited by irreversible visual field constriction, an adverse reaction to the drug reported in approximately 40% of patients. Given the evidence suggesting an idiosyncratic drug response, we set out to detect genetic variation of strong, clinically relevant effect that might guide clinicians in the safe, controlled prescribing of this otherwise usefuldrug.

METHODS

Patients with a history of at least 1-year exposure to vigabatrin were enrolled at two independent referral centers. Using Goldmann perimetry, visual fields and the extent of constriction were calculated for each patient. We examined the correlation between the extent of vigabatrin induced visual field constriction and genetic variation across six candidate genes (SLC6A1, SLC6A13, SCL6A11, ABAT, GABRR1 and GABRR2). We availed of HapMap data and used a tagging SNP technique in an effort to efficiently capture all common variation within these genes. We attempted to replicate any positive associations before drawing conclusions from our results.

RESULTS

The degree of visual field constriction correlated with three SNPs and one haplotype in a cohort of 73 patients. However we were unable to replicate these findings in a second independent cohort consisting of 58 patients, suggesting the initial results were possibly false positives, or variants of weak effect.

CONCLUSION

Common variants of strong, clinically relevant effect do not appear to reside in the candidate genes studied here. This does not rule out the presence of genetic variants of weak effect in these genes, nor of variants of strong effect in other genes.

Use of ACTH and prednisolone in infantile spasms: Experience from a developing country

BACKGROUND

Adrenocorticotrophic hormone (ACTH) and prednisone are both used to treat infantile spasms (IS) in West syndrome. In many countries, ACTH is expensive and difficult to obtain whereas, prednisone or prednisolone are cheap, given orally and easily available.

AIMS

The purpose of this retrospective data analysis was to compare the efficacy and cost of ACTH and prednisolone in the treatment of IS from the perspective of a developing country.

METHODS

Patients admitted with West syndrome in Children's Hospital, Islamabad, between January 1995 and December 2001 were included in the analysis. The diagnosis was made after eliciting a history of characteristic seizures and detecting hypsarrhythmia on the EEG. Parents were offered the use of either ACTH administered by intramuscular injection or prednisolone given orally. ACTH was expensive and difficult to obtain whereas prednisolone was cheap and easily available.

RESULTS

One hundred and five children were included in the study. Sixty-three were boys and their age ranged from 2 months to 3 years with a mean of 11 months. Thirty-three children received ACTH injections; 27 showed improvement and 11 remained spasms free after discontinuation of injections. Seventy-two patients were given oral prednisolone, 51 responded and 17 remained spasms free after oral steroids were stopped. Overall outcome was similar in both groups. The cost of ACTH injection was more than 100 times the cost of oral prednisolone.

CONCLUSION

No significant difference was seen in the final outcome in both treatment groups. Since prednisolone is inexpensive, easily available and given orally, it is the preferred mode of therapy.

Steroids in intractable childhood epilepsy: Clinical experience and review of the literature

Steroids and adrenocorticotrophic hormone (ACTH) have been used for the treatment of infantile spasms for several years. However, the use of steroids in the treatment of epilepsy beyond infantile spasms has been limited to only a few studies. We report the experience with steroids in 32 children with intractable epilepsy, not including West syndrome. In 47% there was a decrease in seizure frequency, 25% became seizure free, 11% had a seizure reduction of >50% and 11% had a seizure reduction of <50%. Our study confirms the conclusions of few previous reports of effective adjunctive steroid treatment for children with intractable epilepsy. The possible side effects, however, especially during prolonged therapy remain an important concern.

Pediatric epilepsy surgery: lessons and challenges

Pediatric epilepsy surgery has come of age, from being considered as a last resort in medically refractory focal epilepsy, after failure of numerous antiepileptic drug trials spanning many years, to a preferred treatment option in carefully selected candidates. There have been certain key developments that have catalyzed this change. First, we are able to predict medical intractability earlier during the course of epilepsy. Second, improved understanding of how the maturing brain recovers from neurologic insults has led to earlier consideration of surgical intervention during a window of developmental plasticity. Finally, improved diagnostic and surgical capabilities now enable us to identify more candidates suitable for surgery. At the same time, as the surgical frontier has been rapidly pushed to new horizons, we have also unearthed new challenges. In this review, several pediatric epilepsy syndromes are discussed to highlight these important developments.

Characteristic retinal atrophy with secondary "inverse" optic atrophy identifies vigabatrin toxicity in children

OBJECTIVE

To describe the clinical pattern of retinal atrophy in children caused by the anticonvulsant vigabatrin.

DESIGN

An interventional case series report.

PARTICIPANTS

One hundred thirty-eight patients, mainly infants, were evaluated regularly for evidence of possible vigabatrin toxicity in the Eye and Neurology clinics at the Hospital for Sick Children, Toronto.

METHOD

Sequential clinical and electroretinographic (International Society for Clinical Electrophysiology of Vision standards) evaluations every 6 months.

MAIN OUTCOME MEASURES

Presence of recognizable retinal and optic atrophy in the presence of abnormal electroretinogram (ERG) and other clinical findings.

RESULTS

Three children being treated for seizures with vigabatrin showed definite clinical findings of peripheral retinal nerve fiber layer atrophy, with relative sparing of the central or macular portion of the retina and relative nasal optic nerve atrophic changes. Some macular wrinkling was evident in 1 case. Progressive ERG changes showing decreased responses, especially the 30-Hz flicker response, supported the presence of decreased retinal function.

CONCLUSIONS

A recognizable and characteristic form of peripheral retinal atrophy and nasal or "inverse" optic disc atrophy can occur in a small number of children being treated with vigabatrin. The changes in superficial light reflexes of the retina in children facilitate the clinical recognition of nerve fiber layer atrophy. The macula is relatively spared, although superficial retinal light reflexes indicating wrinkling of the innermost retina suggest early macular toxicity as well. Because these changes are accompanied by electrophysiologic evidence of retinal dysfunction, discontinuation of vigabatrin should be strongly considered.

Pharmacologic treatment of the catastrophic epilepsies

Treatment of the catastrophic epilepsies [infantile spasms (IS), Lennox-Gastaut syndrome (LGS), and progressive myoclonic epilepsy (PME)] remains a challenge to clinicians. For IS, adrenocorticotropic hormone has traditionally been the drug of choice in the United States but may be associated with serious side effects in some patients. Vigabatrin has shown promise in treating IS patients, particularly those with tuberous sclerosis. However, the drug is associated with visual field loss and is not commercially available in the United States. Newer antiepilepsy drugs (AEDs), such as zonisamide, topiramate (TPM), and lamotrigine (LTG), may be useful in patients with IS. Although LTG, TPM, and felbamate are approved in the United States for the treatment of LGS, the overall effectiveness of therapy in patients with LGS is poor. For PME, valproate is a first-line treatment. Zonisamide and levetiracetam also show promise. Supplementation with certain cofactors to correct deficiencies and increase mitochondrial function may be useful in some patients with PME, but response to such therapy is not well documented. Advances in our understanding of the etiologies, mechanisms, and genetics underlying the catastrophic epilepsies may facilitate more effective pharmacologic interventions.

Managing epilepsy in tuberous sclerosis complex

Epilepsy is very common in tuberous sclerosis complex and occurs in 80 to 90% of affected individuals during their lifetime. Onset usually occurs during childhood, and up to one third of children with tuberous sclerosis complex will develop infantile spasms. Although not completely understood, the incidence of epilepsy is thought to relate to the neuropathologic features of the disorder, including cortical tubers and other dysgenetic features. Individuals with tuberous sclerosis complex frequently have epileptiform features to their electroencephalograms. Treatment of epilepsy in tuberous sclerosis complex is similar to epilepsy resulting from other causes and includes anticonvulsant medications, the vagus nerve stimulator, and the ketogenic diet. Vigabatrin has been shown to be particularly effective in treating infantile spasms in the setting of tuberous sclerosis complex. Epilepsy surgery has a very important role in the management of children and adults with pharmacoresistant epilepsy in tuberous sclerosis complex.

Does Glucocorticoid Administration Prevent Late Seizures after Head Injury?

PURPOSE

Preventing posttraumatic epilepsy has been a difficult challenge. In this study we evaluated the association between glucocorticoid administration after traumatic brain injury (TBI) and posttraumatic seizures.

METHODS

We examined a seizure-prevention trial database of 404 patients with severe TBI for exposure to glucocorticoids in the early (<1 week) posttraumatic period. After controlling for seizure risk, we compared the odds of developing first and second late posttraumatic seizures between those that received glucocorticoids and those that did not.

RESULTS

Patients dosed with glucocorticoids within 1 day of their TBI were more likely to develop first late seizures than were those without [p = 0.04; hazard ratio = 1.74; 95% confidence interval (CI), 1.01-2.98]; whereas those receiving glucocorticoids > or =2 days after their injury had no similar association (p = 0.66; hazard ratio = 0.77; 95% CI, 0.23-2.56; p = 0.10 among the three groups). Receiving glucocorticoids within 1 day, or > or =2 days after TBI was not associated with second late seizure development.

CONCLUSIONS

Glucocorticoid treatment after TBI is not associated with decreased late posttraumatic seizures, and early treatment is associated with increased seizure activity.

Changes in the electroretinogram resulting from discontinuation of vigabatrin in children

Electroretinograms (ERGs) have been recorded longitudinally in children before and during treatment with the antiepileptic drug vigabatrin for the past 3.5 years. Vigabatrin induced changes in ERG responses occur in children; the most dramatic changes occur in the oscillatory potentials. The purpose of this study was to identify changes in ERG responses associated with discontinuation of vigabatrin treatment. If vigabatrin-induced changes reverse after discontinuation of the drug we infer that the original change is not an indicator of toxicity. ERG data were analyzed from 17 children who discontinued vigabatrin therapy. The duration of treatment ranged from 5 to 52 months, the age for the first ERG ranged from 6 to 38 months (median 10 months). ERGs were tested using the standard protocol established by the International Society for Clinical Electrophysiology of Vision, with Burian-Allen bipolar contact-lens electrodes. In addition to standard responses we recorded photopic oscillatory potentials (OPs). During vigabatrin treatment OPs show a greater change than other ERG responses, with the early occurring wavelets from the photopic OPs showing the greatest change. With discontinuation of vigabatrin the amplitude of the early wavelets of the photopic OPs increased dramatically compared with amplitudes while taking the drug (paired t-test, p = 0.000075). The scotopic oscillatory potentials also show some recovery. Although changes in oscillatory potentials may occur with vigabatrin toxicity, a large change likely occurs with a non-toxic pharmacological effect of vigabatrin on GABAergic amacrine cells in the inner plexiform layer. Reduction of OPs in children on vigabatrin may not be related to toxicity.

Sulthiame in the Primary Therapy of West Syndrome: A Randomized Double-blind Placebo-controlled Add-on Trial on Baseline Pyridoxine Medication

PURPOSE

West syndrome (WS) is still one of the most difficult to treat epilepsies in infancy. Sulthiame (STM), which is commonly used in some countries in the treatment of benign focal epilepsies in childhood, has been suggested to be effective in WS too. This prospective, randomized placebo-controlled study was designed to prove or refute this hypothesis.

METHODS

Thirty-seven infants aged between 3.5 and 15 months with newly diagnosed WS received baseline therapy with pyridoxine (PDX). The children were randomized in a double-blind fashion to STM (n = 20) or placebo (n = 17), starting at day 4 at a moderate dose of 5 mg/kg body weight. Without complete cessation of infantile spasms (ISs) and resolution of hypsarrhythmia as the definition criteria of a response, the dose was doubled at day 7. The final examination was undertaken at the end of day 9.

RESULTS

Based on the intention to treat, six (30%) of 20 patients responded to STM (p < 0.025), as did six (35%) of 17 infants fulfilling the study criteria (p < 0.01). Patients with tuberous sclerosis did not respond to STM (n = 3) No patient responded to placebo. One patient in the verum group was withdrawn because of reversible somnolence.

CONCLUSIONS

As no child in the placebo group responded to the baseline PDX therapy, nor did any child in the STM group during the first 3 days of baseline therapy, PDX does not seem to be effective in WS. STM has a positive effect in the primary therapy of WS, comparable to that of vigabatrin.

Treatment Strategies for Myoclonic Seizures and Epilepsy Syndromes with Myoclonic Seizures

Despite the availability of numerous treatment options, the diagnosis and treatment of myoclonic seizures continue to be challenging. Based on clinical experience, valproate and benzodiazepines have historically been used to treat myoclonic seizures. However, many more treatment options exist today, and the clinician must match the appropriate treatment with the patient's epilepsy syndrome and its underlying etiology. Comorbidities and other medications must also be considered when making decisions regarding treatment. Rarely, some antiepileptic drugs may exacerbate myoclonic seizures. Most epileptic myoclonus can be treated pharmacologically, but some cases respond better to surgery, the ketogenic diet, or vagus nerve stimulation. Because myoclonic seizures can be difficult to treat, clinicians should be flexible in their approach and tailor therapy to each patient.