Newly diagnosed epilepsy in children: presentation at diagnosis

Incidence of unprovoked seizures and epilepsy in Iceland and assessment of the epilepsy syndrome classification: a prospective study

BACKGROUND

No population-based incidence studies of epilepsy have studied syndrome classification from the outset. We prospectively studied the incidence of a single unprovoked seizure and epilepsy in the population of Iceland, and applied the syndrome classification endorsed by the International League Against Epilepsy to this population.

METHODS

We used a nationwide surveillance system to prospectively identify all residents of Iceland who presented with a first diagnosis of a single unprovoked seizure or epilepsy between December 1995 and February 1999. All cases were classified by seizure type, cause or risk factors, and epilepsy syndrome.

RESULTS

The mean annual incidence of first unprovoked seizures was 56.8 per 100,000 person-years, 23.5 per 100,000 person-years for single unprovoked seizures, and 33.3 per 100,000 person-years for epilepsy (recurrent unprovoked seizures). Incidence was similar in males and females. Partial seizures occurred in 40% and a putative cause was identified in 33%. Age-specific incidence was highest in the first year of life (130 per 100,000 person-years) and in those 65 years and older (110.5 per 100,000 person-years). Using strict diagnostic criteria for epilepsy syndromes, 58% of cases fell into non-informative categories. Idiopathic epilepsy syndromes were identified in 14% of all cases.

INTERPRETATION

Findings are consistent with incidence studies from developed countries. Although the epilepsy syndrome classification might be useful in tertiary epilepsy centers, it has limited practicality in population studies and for use by general neurologists.

Models for generalized seizures

It is clear that a variety of gene defects can result in absence seizures. In addition, the problem is complicated by observation that the behavioral and EEG phenotype in some of the models is highly dependent on pedigree. Despite these difficulties, advances in molecular-genetic techniques coupled with electrophysiological studies are likely to be highly revealing. While the relationship between the rat and mice models and the human condition thus far remains tenuous, insights from the animal models have already been very helpful in choosing antiepileptic drugs and providing insights into the pathophysiology of the seizures.

Occipital lobe epilepsy: clinical characteristics, surgical outcome, and role of diagnostic modalities

PURPOSE

To assess the role of various diagnostic modalities, to identify surgical prognostic factors and concordances with presurgical evaluations, and to characterize the clinical features of occipital lobe epilepsy (OLE), we studied 26 patients who were diagnosed as having OLE and underwent epilepsy surgery.

METHODS

Diagnoses were established by standard presurgical evaluations, which included magnetic resonance imaging (MRI), fluorodeoxyglucose-positron emission tomography (FDG-PET), ictal single-photon emission computed tomography (SPECT), scalp video-EEG monitoring, and intracranial EEG monitoring. After epilepsy surgery, patients were followed up for >2 years.

RESULTS

Sixteen (61.5%) of the 26 became seizure free after surgery, and another eight patients had a favorable outcome. Sixteen of the 26 patients experienced a type of visual aura (i.e., visual hallucination, visual illusion, blindness, or a field defect). Nine patients had both automotor seizures and secondary generalized tonic-clonic seizures at different times. Interictal EEG showed correctly localizing spikes in 10 of the 16 patients who became seizure free, and in three of the 10 non-seizure-free patients. MRI correctly localized the lesion in seven of these 16 seizure-free patients, and in three of the 10 non-seizure-free patients. FDG-PET correctly localized the lesion in eight of the 16 seizure-free patients, and in three of nine non-seizure-free patients. Ictal SPECT was performed in 19 patients and correctly localized the lesion in only three of 12 seizure-free patients, and in four of seven non-seizure-free patients. Ictal EEG correctly localized the lesion in 13 of the 16 seizure-free patients, and in five of the 10 non-seizure-free patients. No significant relation was found between the diagnostic accuracy of any modality and surgical outcome. The localizations of epileptogenic zones by these different diagnostic methods were complementary. The concordance of three or more modalities was significantly observed in seizure-free patients (p = 0.042). However, no definite relation was observed between the presence of lateralizing clinical seizure manifestation and surgical outcome (p = 0.108).

CONCLUSIONS

Some specific auras indicated an occipital epilepsy onset. Various diagnostic methods can be useful to diagnose OLE, and a greater concordance between presurgical evaluation modalities indicates a better surgical outcome.

Status epilepticus after the initial diagnosis of epilepsy in children

OBJECTIVES

To determine the risk and predictors of status epilepticus in children after they have been diagnosed with epilepsy.

METHODS

In a prospective community-based cohort study of 613 children, the occurrence of status epilepticus after the initial diagnosis of epilepsy was ascertained. Parents were called every 3 months, and interval medical records were reviewed every 6 months. Predictors of primary interest included a history of status before the diagnosis of epilepsy, age at onset, underlying etiology, and epilepsy syndrome. Data were analyzed with chi2 tests, Kaplan-Meier analyses, and Cox proportional hazards models.

RESULTS

Of 613 children followed a median of 8.0 years, 58 (9.5%) had > or =1 episode of status epilepticus during follow-up evaluation. The first episode occurred a median of 2.5 years after initial diagnosis (range, <1 month to 8.8 years). A history of previous status epilepticus was strongly associated with subsequent status epilepticus (18/56 [32.1%] vs 40/557 [7.2%]; p < 0.0001). Younger age at onset and symptomatic etiology contributed independently to the risk of status epilepticus. Mortality was higher in children with status epilepticus before diagnosis, largely secondary to underlying cause.

CONCLUSIONS

Status epilepticus occurs in approximately 10% of children after initial diagnosis of epilepsy. Status epilepticus before initial diagnosis, young age at onset, and symptomatic etiology independently influence the risk of status epilepticus. In those without status epilepticus before diagnosis, the risk is modest and is realized over a prolonged period. For children at highest risk, maintaining abortive therapy in the home may be a reasonable precaution.

Longitudinal assessment of adaptive behavior in infants and young children with newly diagnosed epilepsy: influences of etiology, syndrome, and seizure control

OBJECTIVES

The outcomes of childhood-onset epilepsy are highly varied and have several potential determinants. We examined the independent effects of syndrome type, seizure control, and etiology over time on adaptive behavior as measured by the Vineland Scales of Adaptive Behavior.

METHODS

As part of a prospective community-based study of newly diagnosed epilepsy, parents of children who were younger than 3 years at the time of initial onset of epilepsy completed the Vineland Adaptive Behavior Scales screener version at entry into the study and once a year thereafter for up to 3 years. Longitudinal analyses were performed on the composite score as the primary outcome and on the 4 domain scores (communication, socialization, motor, and daily living) as confirmatory/secondary outcomes to determine the effects of syndrome (epileptic encephalopathy or other), seizure control (intractable or not), and etiology (symptomatic or not) on adaptive behavior at the time of initial diagnosis and over time.

RESULTS

A total of 613 children were enrolled in the study, and 191 (31%) of these children met the age criterion for this analysis. Of these, 172 (90%) had adequate follow-up and had completed baseline and at least 1 subsequent Vineland assessment. Overall, Vineland scores (composite and individual domains) were somewhat below average at baseline (initial diagnosis). All declined significantly over time. All of the effects at baseline, however, were limited to children with epileptic encephalopathies and symptomatic etiology. Substantial declines over time occurred in these children, and there was an independent effect of intractable seizures as well. In children with none of these factors ( approximately 75% of the study group), baseline scores were consistent with average performance for the test norms and there was no evidence of any decline over time.

CONCLUSIONS

Children with an underlying symptomatic etiology or a syndrome that can be characterized as 1 of the epileptic encephalopathies demonstrate impaired adaptive behavior at the time of initial diagnosis and experience additional declines in assessments of age-adjusted performance over time. Our results suggest that future seizure outcome is not strongly reflected in adaptive behavior at initial diagnosis but that it takes its toll on the child over time. Understanding how each of these factors affects development and how they interact with each other is the next step in designing effective interventions for lessening the impact of these disorders on the child. In the majority of children with onset of epilepsy during infancy or early childhood, adaptive behavior is within the normal range and does not show any evidence of declining over time. Although this is encouraging, it does not contradict other studies that have demonstrated behavioral and relatively subtle cognitive difficulties in school-aged children with epilepsy. Long-term follow-up in this cohort will permit us to examine the predictive value of the Vineland for later behavioral and cognitive difficulties in this group that, so far, seems to be doing well.

Modeling remission and relapse in pediatric epilepsy: application of a Markov process

Seizure outcome is frequently described in terms of patients ever attaining remission or being in terminal remission. Outcomes are more complicated and, over many years, repeated remission and relapses may occur. These are difficult to quantify with standard survival techniques used in analysis of remission and relapse. The Markov process, which allows one to track a patient's state (remission or not) over time, provides a suitable approach for studying repeated remission and relapse. In a prospective community-based study of children followed from the point of the initial diagnosis of epilepsy, we examined the probability of repeated remission and relapse over up to three different remission episodes (minimum 1 year each) per patient. The role of epilepsy syndrome was the main determinant of remission-relapse patterns considered in the analysis. Two different Markov models were used, one involving three states and the other seven states. Of 613 children initially recruited into the study, 602 were followed at least 1 year and thus eligible for the analysis. Almost 90% of the cohort experienced a remission; however, almost half then relapsed. Second remissions occurred in 81% of those who relapsed of whom 38% relapsed again. A third remission occurred in 82% of those after a second relapse of whom 58% relapsed yet again. After the first 2 years, approximately 70% of the cohort was in remission, 20% was no longer in remission having relapsed, and 10% had never been in remission. Significant differences were seen by underlying epilepsy syndrome. Children with one of the epileptic encephalopathies were least likely of all syndrome groups ever to remit. Those with symptomatic partial epilepsies were less likely to remit than children with any of the other syndromes, idiopathic partial or generalized, cryptogenic partial, and unclassified. Differences between these last groups became apparent when considering their subsequent remission and relapse histories. These differences were best seen in the seven-state model. For example, idiopathic partial epilepsies were most likely to enter remission and never relapse. By contrast, idiopathic generalized and cryptogenic partial epilepsies were more likely to remit and relapse repeatedly. The Markov approach provides an alternative to standard survival techniques for understanding remission and relapse outcomes in epilepsy. Its advantage is that it allows one to track the individuals' outcome over time even as the condition fluctuates. The technique would also be applicable in virtually any remitting-relapsing disorder.

How can paediatric epilepsy services best be delivered in secondary care?

OBJECTIVE

To produce practical evidence-based guidelines for the management of paediatric epilepsy in secondary care settings.

DESIGN

Question-specific systematic literature review and local service audit.

MAIN OUTCOME MEASURES

Grade of recommendation for specific management issues.

RESULTS

There is little good quality research to support many existing epilepsy guidelines for secondary care.

CONCLUSION

Practical guidelines for the provision of children's epilepsy services can be evidence influenced but until more relevant research is undertaken, not evidence based.

Understanding the delay before epilepsy surgery: who develops intractable focal epilepsy and when?

Intractable temporal lobe epilepsy that is surgically treated in adulthood is a disorder whose onset frequently occurs during childhood and early adolescence. The average duration of epilepsy prior to surgery is on the order of 20 years. The long delay between onset and surgery has at least two components: time from onset to intractability and time from evidence of intractability to surgery. The first interval is prolonged >10 years especially if the onset is during childhood. This suggests a complex natural history that we have not fully appreciated as well as a potential window of opportunity for early secondary intervention. The second interval is also prolonged, especially if onset was during childhood. Reasons for this are not fully clear but may include a reluctance to consider surgery and perhaps difficulty deciding whether seizures are sufficiently intractable to warrant surgery especially after what may have been a relatively benign initial course. Factors involved in the second delay need to be better understood so that surgical interventions can be appropriately targeted early rather than late, thereby reducing serious social, psychological, and educational consequences associated with uncontrolled seizures.

Episousse: Incidence of Newly Presenting Seizures in Children in the Region of Sousse, Tunisia

PURPOSE

To evaluate the incidence of newly presenting seizures in children in the area of Sousse, Tunisia.

METHODS

From June 1, 1998, to May 31, 1999, all children aged 1 month to 15 years with first provoked and unprovoked seizures were included. Children with febrile seizures were excluded. All suspected cases were systematically referred to the Department of Functional Explorations of the Nervous System where a detailed questionnaire was filled out by a neurologist. All the patients underwent an EEG. Only 12 patients had a computed tomography (CT) scan.

RESULTS

A total of 175 patients were included. Eighteen (10.3%) patients had acute symptomatic seizures, and 157 patients had unprovoked seizures. The incidence rate of first unprovoked seizures was 102.1/100,000. In this latter group, some epileptic syndromes were individualized on strict electroclinical criteria.

CONCLUSIONS

However, nearly 75% of the cases remained cryptogenic, one of the major reasons that no predominant risk factor was identified in this population.

Childhood epilepsy: what is the evidence for what we think and what we do?

This article reviews the strength of the evidence that underlies the current approach to the management of childhood epilepsy. The authors reviewed published, peer-reviewed English literature accessed through PubMed and Cochrane reviews with evidence rated as Class 1 (strongest) to Class 4 (weakest). There is considerable inaccuracy in the diagnosis of seizures and epilepsy syndromes. Sound information supports the consensus that the diagnosis of epilepsy should await two unprovoked seizures. Population-based studies indicate that remission from childhood onset epilepsy occurs in at least 50% of children. It is easier to predict a good seizure outcome than a poor one. Absence of concomitant neurologic handicap and onset before about 12 years of age are the most consistent predictors of remission. Intractability is poorly defined and difficult to predict until several antiepilepsy drugs have been used and failed to control the seizures. Most epilepsy syndrome diagnoses do not yield an accurate prognosis. Social outcome appears unsatisfactory in about 50% of cases without intellectual handicap. Death is rare in childhood epilepsy. Those without severe neurologic handicaps have the same mortality as the general population. We identified only 27 published randomized trials of antiepilepsy drugs in children that compare the efficacy of antiepilepsy drugs, offer treatment of syndromes currently without successful treatment, or have negative effects. There is a pressing need for better definitions of seizures and epilepsy syndromes. The causes of poor social outcome are unclear. Intractability needs a clear definition and randomized trials comparing treatment regimes are sadly lacking.

Systematic review and meta-analysis of incidence studies of epilepsy and unprovoked seizures

PURPOSE

To evaluate the methodology of incidence studies of epilepsy and unprovoked seizures and to assess the value of their findings by summarizing their results.

METHODS

A Medline literature search from January 1966 to December 1999 was conducted. In each selected study, key methodologic items such as case definition and study design were evaluated. Furthermore, a quantitative meta-analysis of the incidence data was performed.

RESULTS

Forty incidence studies met the inclusion criteria. There was considerable heterogeneity in study methodology, and the methodologic quality score was generally low. The median incidence rate of epilepsy and unprovoked seizures was 47.4 and 56 per 100,000, respectively. The age-specific incidence of epilepsy was high in those aged 60 years or older, but was highest in childhood. Males had a slightly higher incidence of epilepsy (median, 50.7/100,000) than did females (median, 46.2/100,000), and partial seizures seemed to occur more often than generalized seizures. Developing countries had a higher incidence rate of epilepsy (median, 68.7/100,000) than did industrialized countries (median, 43.4/100,000). Similar results were found for unprovoked seizures. The incidence of epilepsy over time appears to decrease in children, whereas it increases in the elderly.

CONCLUSIONS

The age-specific incidence of epilepsy showed a bimodal distribution with the highest peak in childhood. No definitive conclusions could be reached for the incidence of unprovoked seizures and other specific incidence rates of epilepsy. More incidence studies with an adequate study methodology are needed to explore geographic variations and time trends of the incidence of epilepsy and unprovoked seizures.

The epidemiology of the epilepsies in children

The epilepsies are a heterogeneous collection of neurological conditions and syndromes characterized by recurrent, unprovoked, paroxysmal seizure activity. There are several types of epileptic seizures and syndromes that are unique to children, including infantile spasms, Lennox-Gastaut syndrome and absence seizures. Febrile seizures and neonatal seizures, while not epilepsy, are relatively common types of seizures in infants and children and are likely markers of risk of later epilepsy. Thus, it is important to consider the epidemiological features of the epilepsies as they occur specifically in infants and children. The purpose of this review is to summarize what is currently known about the epidemiology of the childhood epilepsies and to identify promising areas for further population-based studies. The epilepsies are an important cause of neurological morbidity in children. The average annual rate of new cases (incidence) of epilepsy is approximately 5-7 cases per 10,000 children from birth to age 15 years, and in any given year, about 5 of every 1,000 children will have epilepsy. There is evidence that the incidence of the epilepsies in some populations of children may be decreasing over time, and this possibility merits further investigation. Factors that are known to increase risk of the epilepsies in children include congenital malformations of the central nervous system (CNS), moderate or severe head trauma, CNS infections, certain inherited metabolic conditions, and genetic factors. However, these account for only 25% to 45% of cases, and thus, the etiology of most cases of the epilepsies remains obscure. The paucity of well-controlled etiological studies is due largely to formidable methodological problems in conducting epidemiological studies of the epilepsies. The prognosis for seizure control is generally good, although children with remote symptomatic seizures and those with additional neurological disabilities do less well.

Epilepsy in children in Benin City, Nigeria

The pattern of epilepsy in children in Nigeria showed little difference from that seen in children in western countries, except that birth asphyxia was relatively common as a cause and there was a longer time between onset of seizures and parents seeking medical care. It was estimated that good control of seizures was achieved in 52.9% of children, but more than a quarter attended the clinic only once or twice and the reasons for this are not known. The response to medication was less satisfactory for children under 1 year, a result consistent with most other studies. Some uncommon forms and associations of epilepsy were recognised. An EEG was not essential for management but was useful for the diagnosis of syndromes. Treatment was equally effective when commenced 5 years or more after the onset of seizures. The anti-convulsant used for most children was phenobarbitone which had to be discontinued in only two cases because of side-effects. Phenobarbitone has been successfully used to treat epilepsy by primary health workers in rural Africa and this is expected to continue in the future.

Nonsymptomatic generalized epilepsy in children younger than six years: excellent prognosis, but classification should be reconsidered after follow-up: the Dutch Study of Epilepsy in Childhood

PURPOSE

To assess the prognosis and the accuracy of the epilepsy classification in young children with nonsymptomatic generalized epilepsy.

METHODS

Of the cohort of the Dutch Study of Epilepsy in Childhood (n = 466), all children younger than 6 years with a diagnosis of idiopathic (IGE) or cryptogenic (CGE) generalized epilepsy either at intake (n = 108) and/or after 2 years of follow-up (n = 102) were included. The number of reclassifications after 2 years was determined, and the reasons for reclassification were analyzed. All children receiving a diagnosis of IGE or CGE at 2 years were followed up for 5 years to study their outcome in terms of terminal remission (TR). Data on their level of intellectual functioning were collected at the start of this analysis.

RESULTS

The epilepsy syndrome was reclassified in 17 children. In 14 of them, the seizure type also was reclassified, and in three, the course of the epilepsy determined the new epilepsy type. Two other children had a reclassification of their seizure types without a change of the epilepsy type. Many children were categorized as having IGE not otherwise specified. In all probability, this is a heterogeneous group, containing patients with various epilepsy syndromes, with generalized tonic-clonic seizures as a common hallmark. Of the 102 children with IGE or CGE at 2 years of follow-up, 75% had a TR of >6 months after 2 years, and 85% a TR of >or=1 year after 5 years.

CONCLUSIONS

In a fair proportion of children with nonsymptomatic generalized epilepsy in this age group, it is not possible to classify firmly the epilepsy and/or the seizures immediately after the intake. Instead, they are reclassified during the course of the disease. This and the apparent heterogeneity of the category IGE not otherwise specified point to inherent drawbacks of the current International League Against Epilepsy (ILAE) classification of epilepsy and epileptic syndromes. The prognosis of IGE at this young age is generally excellent.

Is refractory epilepsy preventable?

About a third of the patients diagnosed with epilepsy will not be fully controlled with antiepileptic drugs (AEDs), and many of them will have frequent and disabling seizures. These patients will undergo multiple drug trials, most often without complete seizure remission. Moreover, refractory epilepsy is associated with increased morbidity (from seizures and medications), social isolation, unemployment, and overall reduced quality of life. There is evidence that refractory epilepsy can be a progressive disorder, which, if controlled early, might never develop into a full syndrome with all of its associated sequelae. The difficulty lies in identifying at an early stage patients who are likely to progress to intractability. No currently known markers enable clinicians to make this identification with confidence. Advances in pharmacogenomics and our understanding of pharmacologic responsiveness in epilepsy may change this situation. Even now, we are able to identify many patients with a poor prognosis earlier than before, particularly in the pediatric population, in which syndromic classification may provide an approach to predict intractability. The early initiation of aggressive therapy may improve outcome and overall quality of life.

Update on the epidemiology and prognosis of pediatric epilepsy

Epilepsy is among the most common serious neurologic disorders in childhood. Epidemiologic studies over the past few decades have greatly increased current knowledge of the incidence and prognosis of seizures. Newer epidemiologic studies have used population- or community-based cohorts, and careful attention has been given to etiology and specific epilepsy syndromes, the two most important factors affecting prognosis. Risk of epilepsy is highest in patients with an associated serious neurologic abnormality, such as mental retardation or cerebral palsy. More than two thirds of patients with childhood-onset epilepsy ultimately achieve remission. Of those attaining remission on medications, approximately 70% remain seizure free when medications are discontinued. Mortality is increased in patients with epilepsy, but the increased mortality risk in childhood-onset epilepsy is primarily seen in patients with neurologic abnormalities or intractable epilepsy. Although long-term seizure outcomes are generally favorable, childhood-onset epilepsy is associated with adverse long-term psychosocial outcomes, even in patients attaining remission. This review summarizes recent data on the epidemiology and prognosis of pediatric epilepsy.

Two-year remission and subsequent relapse in children with newly diagnosed epilepsy

PURPOSE

Although remission is the ultimate measure of seizure control in epilepsy, and epilepsy syndrome should largely determine this outcome, little is known about the relative importance of syndrome versus other factors traditionally examined as predictors of remission or of relapse after remission. The purpose of this study was to examine remission and relapse with respect to the epilepsy syndrome and other factors traditionally considered with respect to seizure outcome.

METHODS

A prospectively identified cohort of 613 children with newly diagnosed epilepsy was assembled and is actively being followed to determine seizure outcomes. Epilepsy syndrome and etiology were classified at diagnosis and again 2 years later. Remission was defined as 2 years completely seizure-free, and relapse as the recurrence of seizures after remission. Multivariable analysis was performed with the Cox proportional hazards model.

RESULTS

Five hundred ninety-four of the original 613 children were followed > or = 2 years (median follow-up, 5 years). Remission occurred in 442 (74%), of whom 107 (24%) relapsed. On multivariable analysis, idiopathic generalized syndromes and age at onset between 5 and 9 years were associated with a substantially increased remission rate, whereas remote symptomatic etiology, family history of epilepsy, seizure frequency, and slowing on the initial EEG were associated with a decreased likelihood of attaining remission. Young onset age (<1 year) and seizure type were not important after adjustment for these predictors. Relapses occurred more often in association with focal slowing on the initial EEG and with juvenile myoclonic epilepsy. Benign rolandic epilepsy and age at onset <1 year were associated with markedly lower risks of relapse. About one fourth of relapses were apparently spontaneous while the child was taking medication with good compliance, and more than half occurred in children who were tapering or had fully stopped medication.

CONCLUSIONS

A large proportion of children with epilepsy remit. Symptomatic etiology, family history, EEG slowing, and initial seizure frequency negatively influence, and age 5-9 years and idiopathic generalized epilepsy positively influence the probability of entering remission. Factors that most influence relapse tend to be different from those that influence remission.

West syndrome in Thailand: a hospital-based survey

The prevalence of West syndrome in Thailand had not been studied. During January 1997 to December 1999, at the Department of Pediatrics, Ramathibodi Hospital, Bangkok, Thailand, of the total 628 first seen epileptic patients, aged 0-15 years, 31 patients (4.9%) with West syndrome were encountered. Sixteen were males. The mean age at presentation was 9.7 months (range 4-32 months) and at seizure onset was 5.7 months (range 2-11 months). Twenty-two patients had typical spasms, four each had generalized tonic seizures and focal seizures prior to the onset of infantile spasms, and another patient had myoclonic seizures. Nineteen patients were classified as symptomatic. Electroencephalogram revealed hypsarrhythmia in six patients, multifocal independent epileptiform discharges in 24 patients, and focal epileptiform discharges in four patients. Abnormal brain-imaging findings were demonstrated in six of the 11 patients investigated. Vigabatrin was given to 17 patients whereas one patient was given valproate. Others who had been severely retarded were given phenobarbital in combination with benzodiazepine. Six patients were lost to follow-up. Of the remaining patients, the duration of follow-up ranged from 7 to 44 months (mean 28 months). Infantile spasms disappeared in 11 patients, persisted in six patients, and changed to other form in eight patients. The developmental outcome was apparently normal in five, slightly delayed in four, moderately delayed in ten, and severely delayed in eight patients.

Incidence of epilepsies and epileptic syndromes in children and adolescents: a population-based prospective study in Germany

PURPOSE

To estimate the incidence rate of epilepsies and epileptic syndromes in German children and adolescents aged 1 month to <15 years, and to provide data on their classification.

METHODS

A population-based prospective study was performed between July 1, 1999, and June 30, 2000. All children aged 1 month to <15 years with a newly diagnosed epilepsy or epileptic syndrome were recorded by private pediatricians, EEG laboratories, and the two University Children's Hospitals in the neighboring cities of Heidelberg and Mannheim. The diagnoses were classified according to the International Classification of Epilepsies and Epileptic Syndromes of the International League Against Epilepsy (ILAE).

RESULTS

The total age-adjusted annual incidence rate was 60/100,000 (95% confidence interval, 42-84), with the highest incidence in the first year of life (146/100,000). Focal epilepsies or epileptic syndromes (58%; incidence rate, 35/100,000) were more common than were generalized ones (39%; incidence rate, 24/100,000), and 3% (incidence rate, 2/100,000) of the epilepsies or epileptic syndromes were undetermined. The rate of idiopathic (47%; incidence rate, 29/100,000) and symptomatic or cryptogenic epilepsies (50%; incidence rate, 30/100,000) was equal. No significant difference in incidence between boys and girls was found.

CONCLUSIONS

Incidence rates for epilepsy in German children aged 1 month to <15 years are about equal to those of other countries in Europe and North America. In accordance with studies from the United States and from many European countries, incidence was highest in the first year of life, and no difference in the incidence between girls and boys was found. In Germany as throughout Europe, idiopathic generalized epileptic syndromes are more often diagnosed than in the United States.

Mortality risk in children with epilepsy: the Dutch study of epilepsy in childhood

OBJECTIVE

Long-term follow-up studies of patients with epilepsy have revealed an increased mortality risk compared with the general population. Mortality of children who have epilepsy in modern times is as yet unknown. Therefore, the objective of this study was to determine mortality of children who have epilepsy in comparison with the general population.

METHODS

Between August 1988 and August 1992, 472 children, aged 1 month to 16 years, who presented in 1 of the participating hospitals with 2 or more newly diagnosed unprovoked seizures or at least 1 status epilepticus were enrolled in the study. All children were followed for 5 years or until death. The number of deaths observed during follow-up was compared with the expected number of deaths in the same age group in the general population in the Netherlands.

RESULTS

Nine children died during follow-up, amounting to a mortality rate of 3.8/1000 person-years, which is sevenfold higher than expected (95% confidence interval = 2.4-11.5). No deaths were observed among the 328 children who had epilepsy of nonsymptomatic cause. All deceased children had epilepsy that was caused by a static or progressive neurologic disorder (mortality risk = 22.9; 95% confidence interval = 7.9-37.9). None of them died from sudden unexpected and unexplained death of epilepsy.

CONCLUSIONS

In our cohort, we found no indication that children who have nonsymptomatic epilepsy have an increased mortality risk compared with the general population, whereas children who have symptomatic epilepsy have a 20-fold increased mortality risk. These data provide guidance for counseling parents of children who have epilepsy.

Newly diagnosed unprovoked epileptic seizures: presentation at diagnosis in CAROLE study. Coordination Active du Réseau Observatoire Longitudinal de l' Epilepsie

PURPOSE

We describe first unprovoked seizures and newly diagnosed epilepsies at initial presentation, with a special emphasis on epilepsy syndromes, in a large cohort recruited in the mid-1990s in France.

METHODS

The French Foundation for Research on Epilepsy set up a network to conduct a prospective study of patients with newly diagnosed unprovoked seizures. Information was provided by 243 child or adult neurologists. Four neurologists classified each case according to the International League Against Epilepsy (ILAE) criteria. First-seizure patients and patients with previously undiagnosed seizures were compared.

RESULTS

Between May 1, 1995, and June 30, 1996, 1,942 patients aged from 1 month to 95 years were identified: 926 (47.7%) with a single seizure and 1,016 (52.3%) with newly diagnosed epilepsy. All but 17 patients had EEGs. In the first-seizure and newly-diagnosed-epilepsy groups, neuroimaging studies were performed in 78.2 and 68.3% of patients, and medication prescribed in 54.1 and 89.6%, respectively. There were significant differences between the two groups with respect to age at onset and diagnosis, sex, etiology, several specific syndromes, as well as the type and presentation of initial seizure. In patients for whom the first seizure was convulsive, only sex, multiple seizures in a day or status epilepticus, and cryptogenic localization-related syndrome differed between the two groups.

CONCLUSIONS

Approximately half of patients who first came to attention for an unprovoked seizure already met epidemiologic criteria for epilepsy. There were significant differences between the types of patients with a first seizure and those with newly diagnosed epilepsy. One or several seizures at diagnosis did not influence the diagnostic assessment of the patients but had a strong influence on the initiation of treatment.

Classification of epilepsy syndromes and role of genetic factors

In this report the types of epilepsy syndromes seen in children in a tertiary referral center in Beirut, Lebanon were studied and the importance of consanguinity and family history in the occurrence of these syndromes was investigated. Records of 230 pediatric patients evaluated during a 1-year period with the diagnosis of single seizure, febrile seizure, or epilepsy were reviewed. Each patient was classified according to the International League Against Epilepsy classification. The occurrence of consanguinity, of family history of febrile seizures or epilepsy, and of other variables was noted. Thirty-six percent of patients were diagnosed with localization-related epilepsy, 21.7% with generalized epilepsy, 11.7% with undetermined generalized or focal, and 24.3% with special syndromes. Twelve percent of patients were diagnosed with idiopathic, 15.1% with symptomatic, and 30.3% with cryptogenic epilepsies. Consanguinity was more common in patients with symptomatic and cryptogenic epilepsies than in patients with idiopathic epilepsies or with incidental seizures (P < 0.05). Family history of epilepsy was more common in patients with symptomatic, cryptogenic, and idiopathic epilepsies than in patients with incidental seizures (P < 0.05). Family history of febrile seizures but not consanguinity was more common in patients with febrile seizures (P < 0.05). We conclude that genetic factors are important not only in idiopathic epilepsies and febrile seizures but also in cryptogenic and symptomatic epilepsies.

Defining early seizure outcomes in pediatric epilepsy: the good, the bad and the in-between

PURPOSE

To examine different approaches to classifying seizure outcomes.

METHODS

In a prospective cohort study of children (N=613) with newly diagnosed epilepsy, seizure outcomes at 2 years were classified as 'good' (> or =1 year remission), 'bad' or 'intractable' (> or = AED failures, > or =1 seizure/month over > or =18 months), and 'indeterminate' (neither 'good' nor 'bad'). Outcomes at 2 years were compared to outcomes in those followed 4 or more years. The associations of three commonly studied prognostic factors, etiology, age at onset, and syndromic grouping with the three-level outcome were assessed.

RESULTS

595 (97.1%) children were followed > or =2 years. A 'good', indeterminate, and 'bad' outcome was present in 314 (52.8%), 235 (38.3%), and 46 (7.7%) children. Problems with treatment were recorded in 64.7% of the indeterminate group. In 390 children followed > or =4 years, early 'good' and 'bad' outcomes persisted in approximately 80%. About half of those with indeterminate 2-year outcomes later achieved remission, 8% met criteria for intractability, and 37% remained indeterminate. Most of the associations with etiology, age, and syndrome were due to variation in the proportion that met criteria for intractability and not remission.

CONCLUSIONS

Many children have indeterminate outcomes, often in association with treatment issues. Clearly 'good' and 'bad' early outcomes can be identified and persist > or =2 years later. In the absence of pharmaco-resistance, lack of early remission (indeterminate outcome) is usually not associated with a bad outcome, at least over the next few years.

How well can epilepsy syndromes be identified at diagnosis? A reassessment 2 years after initial diagnosis

PURPOSE

Epilepsy syndromes can be identified very early in the course of a seizure disorder. It is unclear how accurate and resilient such early classifications are. We compared the classification of epilepsy syndromes made previously on the basis of information available at diagnosis with those made 2 years later in a cohort of children with newly diagnosed epilepsy.

METHODS

Children (n = 613) were prospectively identified at the time of initial diagnosis by participating physicians in Connecticut between 1993 and 1997. Classification of epilepsy syndrome according to International League Against Epilepsy guidelines was made previously based on all relevant information available at diagnosis. All cases were reclassified again after 2 years of additional evidence had accumulated. The distributions of syndromes at diagnosis and at 2 years are compared and reasons for changes examined.

RESULTS

After 2 years, syndromes remained the same in 86.3% of the cohort and changes occurred in 13.7% (n = 84). Evolution of the syndrome occurred in 24 children (3.9%), and rectification to the initial diagnosis occurred in 60 children (9.8%). The most common scenario for evolution of a syndrome was from West syndrome (n = 5), undetermined (n = 4), or symptomatic localization-related epilepsy (n = 3) to the Lennox-Gastaut syndrome. The most common rectification of initial classifications involved incompletely classified syndromes (cryptogenic localization-related and undetermined syndromes; n = 36). In a few instances, a fully specified syndrome was reclassified to another apparently unrelated syndrome. In these cases, initial information at diagnosis had been difficult to interpret.

CONCLUSIONS

Epilepsy syndromes can, for the most part, be identified at the time of initial diagnosis. Two years later, rectifications were made in only 9.8% of cases, and most of these involved syndromes that represented incomplete classifications in the first place. Significant changes were rare. The International League Against Epilepsy classification of the epilepsies can be meaningfully applied in epidemiological studies of newly diagnosed pediatric epilepsy.

Neuroimaging in children with newly diagnosed epilepsy: A community-based study

BACKGROUND

Neuroimaging is generally considered a part of the evaluation of seizures and epilepsy. There is limited information about its current use in the initial evaluation of pediatric epilepsy and about its yield during the initial diagnosis of epilepsy. We describe the patterns in the use and yield of diagnostic imaging in children with newly diagnosed epilepsy in a community-based study.

METHODS

Children were recruited when first diagnosed with epilepsy by participating physicians in Connecticut (1993-1997). Definitions for etiology and underlying epilepsy syndromes are as published by the International League Against Epilepsy.

RESULTS

Of 613 children, 488 (79.6%) had imaging: 388 (63. 3%) magnetic resonance imaging, 197 (32.1%) computed tomography scans, and 97 (15.8%) both. Half of children with idiopathic generalized epilepsy had imaging studies compared with 70% to 100% of children with other forms of epilepsy, depending on the specific type. Etiologically relevant abnormalities were found in 62 (12.7% of those imaged). Fourteen of these children had otherwise completely normal presentations and histories. Their abnormalities included tuberous sclerosis (N = 4), tumors (N = 2), an arteriovenous malformation later diagnosed as a tumor, a cavernous angioma, cerebral malformations (N = 3), and other abnormalities (N = 3). Thirteen of the 14 had partial seizures and 12 had focal electroencephalographic (EEG) findings. Only 1 had neither.

CONCLUSIONS

In children with newly diagnosed epilepsy, neuroimaging reveals a small but significant number of serious abnormalities not previously suspected. Most of these children have partial seizures or focal EEG abnormalities. Neuroimaging should be considered during the evaluation of children with newly diagnosed epilepsy, especially for those with neurologic deficits or partial seizures or focal EEG abnormalities that are not part of an idiopathic localization-related epilepsy syndrome.

Distribution of epilepsy syndromes in a cohort of children prospectively monitored from the time of their first unprovoked seizure

PURPOSE

To assess the distribution of epilepsy syndromes and their stability in children.

METHODS

A cohort of 407 children with a first unprovoked seizure was prospectively recruited and followed up for a mean of 9.4 years. Etiology and epilepsy syndromes were classified by using the International League Against Epilepsy (ILAE) guidelines in the 182 children with two or more seizures. Classification was done both at time of second seizure and at last follow-up. Two-year terminal remission also was analyzed by etiology and epilepsy syndrome.

RESULTS

Etiology of epilepsy syndromes was idiopathic in 45 (25%), cryptogenic in 89 (49%), and remote symptomatic in 48 (26%). In the initial classification, 114 (63%) children had a localization-based epilepsy syndrome including idiopathic in 26, cryptogenic in 34, and symptomatic based on localization or etiology in 54. Twenty-one (12%) children had a generalized epilepsy syndrome, including 19 with primary generalized epilepsy. Forty-seven (26%) cases were in the category of undetermined if focal or generalized. At last follow-up, there was a change in either etiology (n = 16) or the final epilepsy syndrome classification (n = 33) or both (n = 15) in 34 (19%) cases. At time of last follow-up, 144 (79%) of the children with epilepsy were in 2-year terminal remission, and 108 (59%) were in 2-year terminal remission without medications. Factors associated with a favorable prognosis included an idiopathic or cryptogenic etiology and having a localization-based idiopathic epilepsy syndrome.

CONCLUSIONS

After two seizures, childhood-onset epilepsy can be classified by etiology and epilepsy syndrome. Prognosis is favorable in the majority of cases. However, the apparent syndrome may change with longer follow-up. The ability to classify these cases early in the clinical course is important if they are to be used for prognostic purposes.

Epilepsy syndromes in patients with childhood-onset seizures in Finland

Childhood-onset epilepsy is a common disorder. There is insufficient data on the distribution of epilepsy syndromes in the population and their effect on long-term prognosis. This report presents the data on epilepsy syndromes in a childhood-onset epilepsy cohort. A population-based active-prevalence cohort of all children under 16 years of age residing in the catchment area of Turku University Hospital with active epilepsy between 1961 and 1964 was monitored prospectively until 1992. Etiology, seizure type, and epilepsy syndromes were classified according to the recent guidelines of the International League Against Epilepsy. The etiology of seizures was idiopathic in 28%, cryptogenic in 22%, and remote symptomatic in 50%. Seizures were classifiable in 235 patients (96%) and included 157 (64%) with partial seizures and 88 (36%) with generalized seizures. Epilepsy syndromes could be classified in 223 patients (91%) and included 152 (62%) localization-related syndromes, 61 (25%) generalized epilepsy syndromes, and 10 (4%) with syndromes not determined as being focal or generalized. Prognosis for both survival and remission was dependent on etiology and on the specific epilepsy syndrome. The authors conclude that the International League Against Epilepsy guidelines can be successfully applied to a population-based cohort with childhood-onset epilepsy. Accurate classification of syndromes is important because in many cases long-term outcome may be largely determined by the underlying epilepsy syndrome.

Classification of childhood epilepsy syndromes in newly diagnosed epilepsy: interrater agreement and reasons for disagreement

PURPOSE

The International League Against Epilepsy (ILAE) classification of the epilepsies is in increasingly widespread use. The following analysis was done to assess the interrater agreement in classifying epilepsy syndromes in children with newly diagnosed epilepsy.

METHODS

In a prospective, community-based study, 613 children with newly diagnosed epilepsy were recruited. Based on information available at diagnosis or generated as part of the initial diagnostic assessment, three pediatric neurologists independently classified epilepsy syndromes. Interrater agreement was assessed with kappa.

RESULTS

Interrater agreement was extremely good, with kappa scores > or = 0.80 for almost all comparisons. Relatively limited quality of the EEG and seizure information in some cases, as well as discrepancies between the two, were associated with a tendency for more disagreement.

CONCLUSIONS

A high degree of interrater agreement was obtained in this study, indicating that the system for classifying syndromes can be meaningfully used in a community-based sample. Quality of the information, which is often, by necessity, less than optimal in newly diagnosed epilepsy, is a potential barrier to identification of syndromes. A substantial proportion of children were classified into relatively nonspecific syndromes. Over time, additional information may come to light to allow more precise identification of their forms of epilepsy. In an epidemiologic setting, the ILAE classification of the epilepsies can be successfully used with a high degree of reliability to classify newly diagnosed epilepsy in children.