Pharmacologic Treatment of the Catastrophic Epilepsies

Summary:  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.     

Nonpharmacologic Treatment of the Catastrophic Epilepsies of Childhood

Summary:  The catastrophic epilepsy syndromes of childhood are initially treated with a pharmacologic intervention in most cases. However, due to the poor response patients often have to pharmacologic interventions, nonpharmacologic treatment options are an important part of a comprehensive treatment plan for this group of children. Additionally, nonpharmacologic therapy may offer a method to minimize associated morbidity and mortality. This article discusses the use of epilepsy surgery, the ketogenic diet, and vagus nerve stimulation in the treatment of patients with infantile spasms, Lennox-Gastaut syndrome, and progressive myoclonic epilepsy. Efficacy of the nonpharmacologic treatment options, as measured by reduction in seizure frequency, as well as by developmental progress or behavioral improvement, varies according to the specific catastrophic epilepsy disorder and the treatment option.     

Following Catastrophic Epilepsy Patients from Childhood to Adulthood

Summary:  As patients with catastrophic epilepsies move from childhood to adulthood, evolving and innovative therapeutic regimens are often required. However, the goal of providing the best quality of life while minimizing both seizures and side effects remains the same. Clinicians can develop appropriate care plans by being aware of patients' changing needs. Clinical symptoms of the catastrophic epilepsies may change over time; by understanding the natural history of a patient's condition, clinicians can help ease the transition from childhood to adulthood. Additionally, as children with catastrophic epilepsies become adults, medical issues (e.g., medication side effects, tolerance, and dependence) and nonmedical issues (e.g., guardian/caretaker issue, group home applications, and respite care options) must be considered when developing strategies for patient care. Regular assessment of patients, the development of emergency plans, and maintenance of consistency in the delivery of care are also important issues to consider. Finally, a multidisciplinary care plan that incorporates resources from health-care practitioners, social service professionals, and community agencies can be valuable in optimizing treatment for patients with catastrophic epilepsies.     

Efficacy of five days' barbiturate anesthesia in the treatment of intractable epilepsies in children

PURPOSE: To analyze the efficacy of barbiturate anesthesia in the treatment of intractable epilepsies in childhood. METHODS: Anesthesia for 4-5 days with thiopentone sodium was used to treat children with intractable epilepsy in the Department of Pediatrics, Oulu, Finland, from November 1980 through December 1995. The number of epileptic seizures, the number and dosage of antiepileptic drugs (AEDs), and psychomotor development before and after anesthesia were compared. RESULTS: Fifty-four children with intractable epilepsy were treated with barbiturate anesthesia. Twenty-four children had infantile spasms; 22, Lennox-Gastaut syndrome; seven, complex partial epilepsy; and one, myoclonic epilepsy. Twenty-four (44.4%) children had complications during the anesthesia. The seizures recurred in 53 of the 54 patients in a median time of 12 days after the anesthesia. In 42 (78%) children, the seizure frequency returned to a level equal to or higher than that before the anesthesia in a median time of 211 days. The number of AEDs was significantly greater after than before the anesthesia (6.33 vs. 4.8; p < 0.001). Seventeen (32.5%) children were treated surgically after the anesthesia. CONCLUSIONS: Although the seizures are eliminated or the seizure frequency decreases for a short period after the barbiturate anesthesia, the anesthesia does not change the long-term outcome and is therefore inefficient in the treatment of childhood intractable epilepsies.     

Diagnosis of Infantile Spasms, Lennox-Gastaut Syndrome, and Progressive Myoclonic Epilepsy

Summary:  The epilepsies of childhood are distinguished by an interesting dichotomy between the benign and catastrophic disorders. Approximately 50% of children outgrow childhood epilepsy as they mature; although the disorder is disruptive for children and families alike, it is not considered a medical disaster. The catastrophic epilepsies of childhood, in contrast, are associated with significant morbidity and mortality. Infantile spasms, Lennox-Gastaut syndrome, and the progressive myoclonic epilepsies are correlated with significant disability and a multiplicity of underlying etiologies. Accurate diagnosis of both the syndrome and the etiology is very important for treatment purposes, as well as for family education, since many of the disorders have a significant genetic component.     

Treatment of idiopathic west and lennox-gastaut syndromes by intravenous administration of human polyvalent immunoglobulins

Summary A total of 7 patients (3–21 years old) suffering from an intractable primary Lennox-Gastaut syndrome (LGS) were treated with i.v. high doses of polyvalent human immunoglobulins. Of these patients 6 improved following such treatment with a decrease in fits and an improvement in the EEG.Hypotheses about the contribution of the treatment and immunopathological factors in some cases of idiopathic LGS are discussed.     

Occurrence, outcome, and prognostic factors of infantile spasms and Lennox-Gastaut syndrome

PURPOSE: To analyze the occurrence, outcome, and prognostic factors of infantile spasms (IS) and the Lennox-Gastaut syndrome (LGS) in a defined population. METHODS: All children treated because of IS and LGS in the Department of Pediatrics, University of Oulu, from January 1, 1976, until December 31, 1993, who came from the primary catchment area of the hospital were included. Detailed information concerning their individual pre-, peri-, and postnatal medical histories and medical and laboratory examinations were compiled. RESULTS: Thirty-seven children (18 boys) had IS, and 25 (14 boys) had LGS. The occurrence of IS of 0.41/1,000 live births 195% confidence interval (CI), 0.29-0.57/1,000] did not differ significantly from that of LGS, which was 0.28/1,000 live births (95% CI, 0.18-0.41/1,000). Ten (27%) of the 37 patients with IS evolved to LGS, which was 40% of the LGS cases. All the 10 children with both IS and LGS had symptomatic epilepsy, were mentally retarded, and had active epilepsy at the end of approximately 10 years' follow-up. Twenty-six (87%) of the 30 symptomatic IS cases and all the 17 symptomatic LGS cases were due to either congenital or genetic etiologies. The outcome in cryptogenic IS cases was favorable; the risk for a poor neurologic and mental outcome was extremely low; odds ratio, 0.015 (95% Cl, 0.001-0.196), as it was for therapy-resistant epilepsy; odds ratio, 0.013 (95% CI, 0.001-0.166). In LGS patients, cryptogenic etiology did not decrease the risk for a poor outcome. CONCLUSIONS: Cryptogenic etiology is associated with a very low risk for a poor outcome in IS patients, but not in LGS patients. The outcome of IS children and the relation of IS to LGS are determined by the underlying brain disease, not by the epilepsy itself.     

Partial Epilepsies in Infancy: A Study of 40 Cases

Forty patients with partial epilepsy that began before they were aged 3 years were recorded at the Centre Saint-Paul between 1981 and 1986 with a follow-up ranging from 1 year 9 months to 20 years. We analyzed the following data: age at onset, clinical features of seizures at onset and during the follow-up period, ictal and interictal EEG features, etiologic circumstances, evolution of the epilepsy, and psychomotor development. The age of onset was mostly between 2 months and 2 years (more than two thirds of cases). Most had partial symptomatic epilepsy. In nine cases, epilepsy was preceded by febrile convulsions. Seizures at onset were of the following type (in order of decreasing occurrence): unilateral seizures, complex partial seizures, elementary partial seizures, and other seizures, often difficult to classify. A few patients with infantile spasms associated with focal or multifocal EEG abnormalities, differing from West's syndrome, were included in this study. We discuss the problem arising from the classification of infantile seizures and epilepsies.     

Progressive Myoclonus Epilepsies: Clinical and Genetic Aspects

The progressive myoclonus epilepsies (PMEs) are a group of rare genetic disorders previously shrouded in nosological confusion. Recent advances have clarified the features of these disorders and provided a rational approach to diagnosis. The major causes of PME are now known to be Unverricht—Lundborg disease, myoclonus epilepsy ragged-red fiber (MERRF) syndrome, Lafora disease, neuronal ceroid lipofuscinoses, and sialidoses. Over the past 3 years, a series of molecular genetic findings have further refined the understanding of the PMEs. The specific mutation responsible for many cases of MERRF has been identified, and the genes for Unverricht—Lundborg disease and for juvenile neuronal ceroid lipofuscinosis have been linked to chromosomes 21 and 16, respectively. Although the PMEs are among the rarest of the inherited epilepsies, because of molecular genetic discoveries they may soon be the best understood at the neurobiologic level.     

Early Clinical and EEG Features of Infantile Spasms in Down Syndrome

Summary: The combination of West syndrome (WS) and Down syndrome appears not to be coincidental. Fourteen patients free of cardiac malformation or history of perinatal hypoxia were referred and investigated before they had received any treatment and were followed to the mean age of 4.5 years (range 19 months to 14 years). Spasms had onset at the mean age of 8 months (range 4–18 months) in cluster and were symmetrical. Hypsarrhythmia was symmetrical and, after intravenous diazepam (4 patients, 0.5 mg/kg) it disappeared, without any remaining focus. Recorded spasms during a cluster were "independent," with recurrence of hypsarrhythmia between successive spasms, and thus had the ictal and interictal EEG characteristics of idiopathic WS. Seven patients exhibited other types of seizures after WS, consisting of myoclonic jerks, atonic, tonic-clonic or absence seizures, which proved quite easy to control with valproate and/or ethosuximide.     

Epilepsies with astatic seizures of late onset.

In 17 patients with a long course of epilepsy astatic seizures became apparent after the age of 14 years. In the patients' childhood astatic seizures had not been observed. The patients suffered from epilepsies with absences and awakening grand mal or psychomotor fits and sleeping grand mal. The EEG revealed spike-wave variant and spike-and-wave complexes as in the Lennox-Gastaut syndrome. Age dependency of Lennox-Gastaut syndrome is discussed. The described type of epilepsy can be understood as a "Lennox-Gastaut syndrome of late onset".     

West Syndrome and its Related Epileptic Syndromes

Summary: The purpose of this project was to study the relationship between West syndrome (WS) and its related epileptic syndromes, and reconsider the nosological limits of WS. The electroclinical features of 45 patients who experienced spasms in series were investigated, as well as some features not common in patients with WS. All patients were mentally retarded. The patients were divided into three groups: Group 1 consisted of 12 patients with refractory epilepsies with onset in early infancy, group 2 consisted of 5 patients with symptomatic localization-related epilepsies associated with spasms in series, and group 3 consisted of 28 patients with generalized epilepsies who had spasms in series after age 2 years. Partial seizures were the dominant symptom throughout the clinical course and spasms in series associated with atypical hypsarrhythmia appeared transiently during infancy in a significant number of the patients in group 1. In group 2, complex partial seizures (CPS) were the main seizure type and hypsarrhythmia was not observed during the clinical course. The EEGs in group 3 patients showed diffuse slow spike-waves or multifocal epileptic discharges in all but 1 patient. The EEG of the remaining patient still showed hypsarrhythmia at age 8 years. Therefore, group 1 patients should be classified as having WS although cortical mechanisms play a critical role in the occurrence of their seizures. Group 2 patients should be considered as having a type of localization-related epilepsy even though they share a similar pathophysiological mechanism with group 1. In group 3, 1 patient whose EEG still showed hypsarrhythmia was classified as having WS. The other patients should be classified as having generalized epilepsies other than WS.     

Surgery for Catastrophic Localization-Related Epilepsy in Infants

Summary: Cortical resection or hemispherectomy has been reported to result in cessation or dramatic reduction of seizures for small numbers of highly selected infants with severe, intractable epilepsy and developmental delay. However, identification of potential surgical candidates during infancy can be especially challenging because seizure semiology and EEG may sometimes give limited localizing information, e.g., in patients with infantile spasms and hypsarrythmia due to focal cortical dys-plasia or a tumor. In infants as well as older patients, the location of a potentially resectable epileptogenic lesion must be defined by convergence of results from video EEG, anatomic and functional neuroimaging, and clinical examination. Reported outcomes after surgery in small series include 78% of 23 infants seizure-free or with at least 90% seizure reduction (1993 University of California at Los Angeles series), and 75% of 12 infants seizure-free or with rare seizures (1995 Cleveland Clinic series). A tendency of "catch-up" developmental progress after surgery was observed in both series. A few reports of smaller groups of infants noted similar results. Prospective studies are in progress to better define the potential risks and benefits of early surgical intervention for infants and catastrophic localization-related epilepsy.     

The Descriptive Epidemiology of Infantile Spasms Among Atlanta Children

PURPOSE: To determine the population-based epidemiology of infantile spasms (IS) among Atlanta children. METHODS: By using data from a cross-sectional, population-based surveillance system that included 21 EEG laboratories, we identified children born in 1975-1977 in metropolitan Atlanta with IS. Cumulative incidence up to age 2 years was estimated from the number of children with IS born in the study area in 1975-1977, and age-specific prevalence was calculated from the number of children previously diagnosed with IS who lived in the study area at age 10 years. Data regarding coexisting disabilities were available from the surveillance system for developmental disabilities. RESULTS: The cumulative incidence of IS was 2.9/10,000 live births; half of the children with IS had cryptogenic IS. The age-specific prevalence of IS was 2.0/10,000 among 10-year-old children. Eighty-three percent of 10-year-old children with a history of IS had mental retardation (MR, IQ < or =70); 56% of children with a history of IS had profound MR (IQ <20). Developmental outcome did not differ between the children with cryptogenic IS and those with symptomatic IS. Among the 10-year-old children with profound MR who were living in Atlanta at age 10 years, 12% had a history of IS. Fifty percent of children with IS developed Lennox-Gastaut syndrome (LGS) before age 11 years. CONCLUSIONS: The syndrome of IS is rare in the general population, yet a significant percentage of all children with profound MR and severe childhood epilepsy syndromes in the general population have a history of IS.     

Non-convulsive status epilepticus and audiogenic seizures complicating a patient with asymmetrical epileptic spasms

A female infant suffered from epilepsy since the neonatal period, which evolved into West syndrome at the age of 2 months. Spasms in series and hypsarrhythmia disappeared after treatment with high-dose phenobarbital; however, single spasms persisted with right-sided predominance, and polyspike activity in the left parieto-temporal areas preceded or coincided with these spasms. Magnetic resonance imaging revealed a small calcification in the right occipital area, and positron emission tomography showed hypometabolism over the right hemisphere. Widespread epileptic discharges gradually increased on electroencephalography (EEG) during sleep thereafter. The patient presented with daytime unresponsiveness at 1 year and 6 months, when diffuse, irregular spike and wave activity characterized the waking EEG. Spasms or brief tonic seizures with right-sided predominance were provoked by auditory stimuli during this period, particularly by her mother’s voice, with ictal EEG of right posterior predominant fast activity and subsequent desynchronization. The administration of clobazam resulted in the marked improvement of EEG findings and transient disappearance of spasms. Presumably, certain patients with asymmetrical epileptic spasms may be regarded as a unique type of localization-related epilepsy, and can show an unusual course of evolution in comparison to other cases of epilepsy that evolve after West syndrome.     

Seizures in Series: Similarities Between Seizures of the West and Lennox-Gastaut Syndromes

We observed seizures resembling infantile spasms in patients with Lennox-Gastaut syndrome (LGS). Infantile spasms, the type of seizures that occurs in patients who have West syndrome, have been well characterized by video-EEG studies and typically occur as a series of sudden generalized flexor or extensor jerks. The seizure types that occur in LGS have not been as clearly delineated. Some patients with West syndrome (WS) in early infancy later develop LGS. Using intensive video-EEG monitoring, we evaluated 14 LGS patients who had seizures that occurred in series. Clinically, the seizures greatly resembled infantile spasms, and the ictal EEG changes were identical to those that occur with infantile spasms. These findings expand the number of features known to be shared by these two syndromes and strengthen the hypothesis that the two syndromes represent age-related manifestations of similar epileptogenic processes.