Western driving regulations for unprovoked first seizures and epilepsy

PurposeTo review the legislation for non-commercial driving licenses in the Western world for unprovoked first seizures (UFS) and recurrence of established epilepsy, and to examine available evidence on the road traffic accident (RTA) risk in people with seizures.MethodsRegulations for non-commercial driving licenses were sought from appropriate national or state authorities and epilepsy societies. The literature was searched for consensus guidelines and data relevant to risk analysis, including an appropriate seizure-free period (SFP).ResultsThe SFP varied widely from 3 to 24 months and in most countries no distinction was made between UFS and recurrence of established epilepsy. In the European Union (EU), harmonisation is underway but implementation of the relevant directive has been slow. The excess risk of RTA in epilepsy is minimal, especially compared to other factors such as alcohol, and few accidents result from seizures at the wheel. Risk analysis supports the shortened SFPs that are being enacted in the EU.ConclusionRegulations across the world continue to vary widely, and the available data support rules which are less stringent than those currently in force in many parts of the Western world. The ongoing European harmonisation is encouraging but much work remains to be done in revising legislation elsewhere, and in strengthening the theoretical foundations underpinning driving regulations.     

Incidence of febrile seizures in Finland: prospective population-based study

The objective was to study the incidence of febrile seizures prospectively determined through age 4 years. A standardized randomized cluster sample of nulliparous pregnant women from a geographically defined area were prospectively followed from the beginning of pregnancy through the child's age 4. Data on children eligible for the study (n = 1287), including febrile seizures, sociodemographic data, developmental milestones, and chronic diseases, were prospectively collected from families and health care staff. Data were available for 1033 children. Through age 4, the average annual incidence of febrile seizures was 14 per 1000 person-years (15 for girls and 13.5 for boys). The incidence rate through age 4 was 6.9% (7.3% for girls and 6.5% for boys). The incidence rate of febrile seizures in Finnish children is comparable to that reported previously. The higher figure, based on prospective rather than retrospective data, may give a more accurate picture of the clinical importance of febrile seizures.     

ADHD as a risk factor for incident unprovoked seizures and epilepsy in children

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) occurs more frequently than expected in prevalent cohorts with epilepsy. The association has been attributed to the epilepsy or its treatment, although it is impossible to determine in previous studies which condition occurs first. OBJECTIVES: To conduct a population-based case-control study of all newly diagnosed unprovoked seizures among Icelandic children younger than 16 years to address the question of time order. DESIGN: Children with seizures were matched to the next 2 same-sex births from the population registry. The Diagnostic Interview Schedule for Children was used to make a DSM-IV diagnosis of ADHD in a standardized fashion among cases and controls aged 3 to 16 years. RESULTS: A history of ADHD was 2.5-fold more common among children with newly diagnosed seizures than among control subjects (95% confidence interval [CI], 1.1-5.5). The association was restricted to ADHD predominantly inattentive type (odds ratio [OR], 3.7; 95% CI, 1.1-12.8), not ADHD predominantly hyperactive-impulsive type (OR, 1.8; 95% CI, 0.6-5.7) or ADHD combined type (OR, 2.5; 95% CI, 0.3-18.3). Seizure type, etiology, sex, or seizure frequency at diagnosis (1 or >1) did not affect findings. CONCLUSION: Attention-deficit/hyperactivity disorder occurs more often than expected before unprovoked seizures, suggesting a common antecedent for both conditions.     

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.     

Newly diagnosed single unprovoked seizures and epilepsy in Stockholm, Sweden: First report from the Stockholm Incidence Registry of Epilepsy (SIRE)

Purpose:   To describe and report initial findings of a system for prospective identification and follow-up of patients with newly diagnosed single unprovoked seizures and epilepsy in Stockholm, Sweden, the Stockholm Incidence Registry of Epilepsy (SIRE).
Methods:   From September 2001 through August 2004, a surveillance system has been in use to identify incident cases of first unprovoked seizures (neonatal seizures excluded) and epilepsy among residents of Northern Stockholm, an urban area with approximately 998,500 inhabitants. Potential cases are identified through multiple mechanisms: Network of health care professionals, medical record screening in specific hospital units, including outpatient clinics, emergency room services, and review of requests for electroencephalography (EEG) examination. Potential cases are classified 6 months after the index seizure based on review of medical records.
Results:   After screening approximately 10,500 EEG requests and 3,300 medical records, 1,015 persons met the criteria for newly diagnosed unprovoked seizures (430 single seizures; 585 epilepsy). The crude incidence for first unprovoked seizures and epilepsy was 33.9/100,000 person years, (the same adjusted to the European Standard Million), highest the first year of life (77.1/100,000) and in the elderly. No cause could be identified in 62.4%.
Conclusions:   We have established a sustainable system for prospective identification of new onset epilepsy cases in Stockholm. Despite a possible under-ascertainment, the registry provides a useful starting point for follow-up studies.     

Mortality following a first unprovoked seizure in children: a prospective study

In a prospective study, 407 children with a first unprovoked seizure were followed for a mean of 14.2 years. To date, nine have died. Death was unrelated to seizures in four subjects who had no further seizures and were on no medications. The remaining five subjects all had multiple seizures and were on medications. Treatment following the first seizure would not have altered mortality in any of the nine cases.     

Incidence of seizures during pregnancy, labor and puerperium in epileptic women: a prospective study

154 pregnancies of 140 epileptic patients were observed in a prospective study. The number of seizures during pregnancy and 3 first puerperal months was compared with the number of seizures during the 12 months preceding pregnancy. An increase in the number of seizures was noticed in 32% of the cases, a decrease in 14% and unchanged frequency in 23% of the cases, 31% being seizure-free during the study period. The highest incidence of major convulsive seizures occurred during the last trimester of pregnancy, while the incidence of complex partial seizures was highest during puerperium. No factors were found which may predict the increase in seizures.     

Incidence and risk factors in sudden unexpected death in epilepsy: a prospective cohort study

OBJECTIVE: To determine incidence of and risk factors for sudden unexpected death in epilepsy (SUDEP). METHODS: Three epilepsy centers enrolled 4,578 patients and prospectively followed these patients for 16,463 patient-years. The cohort was screened for death annually. Deaths were investigated to determine whether SUDEP occurred. Potential risk factors were compared in SUDEP cases and in controls enrolled contemporaneously at the same center. RESULTS: Incidence of SUDEP was 1.21/1,000 patient-years and was higher among women (1.45/1,000) than men (0.98/1,000). SUDEP accounted for 18% of all deaths. Occurrence of tonic-clonic seizures, treatment with more than two anticonvulsant medications, and full-scale IQ less than 70 were independent risk factors for SUDEP. The number of tonic-clonic seizures was a risk factor only in women. The presence of cerebral structural lesions and use of psychotropic drugs at the last visit were not risk factors for SUDEP in this cohort. Subtherapeutic anticonvulsant levels at the last visit were equally common in the two groups. No particular anticonvulsant appeared to be associated with SUDEP. CONCLUSIONS: These results support the idea that tonic-clonic seizures are an important proximate cause of SUDEP. This information creates a risk profile for SUDEP that may help direct preventative efforts.     

Prevalence of epilepsy in rural Iceland: a population-based study

PURPOSE: To determine the prevalence of epilepsy (recurrent unprovoked seizures) in the population of rural Iceland. METHODS: Review of records of primary-care facilities for the population of rural Iceland supplemented by review of referrals to electroencephalographic facilities and neurologic specialists to identify all individuals with unprovoked seizures or receiving treatment for epilepsy in the calendar year 1993. RESULTS: Crude prevalence was 4.8 per 1,000 and was 4.8/1,000 after age adjustment to the 1970 United States population. Age-adjusted prevalence was higher in male (5.1) than in female subjects (4.4) and increased with advancing age. Sixty-two percent of prevalence cases were of unknown cause. Sixty-three percent of cases had major motor seizures without aura or generalized epileptiform pattern on EEG. Sixty-four percent of patients had had seizures in the year of observation. Seizure control was inversely correlated with number of medications. Ten percent of the prevalence group was taking no medication, although the frequency of seizures was high in this medication-free group. CONCLUSIONS: Prevalence of epilepsy in rural Iceland is consistent with that reported in recent studies in other developed countries. The data provide insights into the approaches of treatment and use of specialized diagnostic testing in the country. The prevalence is similar to that in other European countries but lower than that reported from rural areas in Latin America.     

The incidence of epilepsy and unprovoked seizures in multiethnic, urban health maintenance organizations

PURPOSE: Studies of the incidence of epilepsy are limited to a few populations in which new cases can be ascertained. Health maintenance organization (HmO) populations were studied to determine the incidence in a multiethnic, urban United States population. METHODS: Cases of initial unprovoked seizure disorder or epilepsy while enrolled in an HMO between 1988 and 1994 were ascertained. Ethnicity was obtained from the medical records and was part of a nested case-control study. RESULTS: There were 197 incidence cases of epilepsy and 275 of initial unprovoked seizure diagnosis. The incidence rate in the age range 0-64 years was 35.5 per 100,000 for epilepsy and 50.9 for initial unprovoked seizure. When compared with population-based studies, rates were slightly higher in children younger than 15, similar for the 15- to 24-year age group, but lower for ages 25-64 years. The ethnicity-specific odds ratios for initial unprovoked seizure, by using non-Hispanic white as the referent, were 1.04 (0.73-1.49) for African-American, 0.97 (0.64-1.48) for Hispanic, and 0.25 (0.08-0.84) for Asian-American. CONCLUSIONS: The lower rate in the HMO population is presumably due to a healthy-worker effect. The ethnicity-specific incidence rates do not differ in this population.     

Seizure recurrence after a first unprovoked seizure in childhood: a prospective study

PURPOSE: To study the risk of recurrence after a first unprovoked seizure in childhood. METHODS: All consecutive patients aged less than 14 years with one or more unprovoked seizures who were attended between January 1, 1987, and June 1, 1996, were included in a prospective study. Clinical features of patients attended after a first seizure and those attended after two or more seizures were compared. Recurrence risk in both groups was estimated by Kaplan-Meier curves. Univariate and multivariate analyses of the potential predictors of recurrence risk were performed for the group of patients attended after a first seizure using the Cox proportional hazards model. RESULTS: Included in the study were 217 children. Kaplan-Meier estimate of recurrence risk was 64% at 5 years, when only patients being attended after a first epileptic seizure were included, compared with 74% when all patients were included. Significant differences in several clinical features were found between patients attended after a first seizure and those attended after two or more seizures. Univariate and multivariate analyses showed that in the overall cohort of patients attended after a first seizure, a symptomatic etiology increased the risk of recurrence, whereas a patient age of 3 to 10 years decreased this risk. In particular, the recurrence risk was 96% at 2 years for symptomatic seizures, compared with 46% for idiopathic/cryptogenic seizures. In the group of patients with idiopathic/cryptogenic seizures, an abnormal electroencephalogram and the occurrence of seizures during sleep increased the recurrence risk, whereas a patient aged 3 to 10 years reduced it. In the group of patients with symptomatic etiology, univariate analysis revealed that there was a lower recurrence risk for patients aged 3 to 10 years. This last finding was not maintained, however, in multivariate analysis. CONCLUSIONS: The recurrence risk depends on the inclusion criteria for enrolling patients. Several factors enable us to predict the recurrence risk after a first unprovoked seizure; the most important of these factors is the etiology of the seizures.     

Transient hyperammonemia in seizures: a prospective study

Purpose: To investigate the incidence and duration of transient hyperammonemia in seizures and to verify the significant confounders related to transient hyperammonemia in seizures. Methods: One hundred twenty‐one noncirrhotic adult patients with seizures admitted to the emergency department were enrolled in the study. Laboratory examination was performed, including plasma ammonia level assessment. In addition, the basic parameters, underlying systemic diseases, and seizure‐related conditions were assessed. The patients were classified into a group with hyperammonemia on arrival and a group without, in order to compare seizure‐related adverse events that occurred during a 9‐month period. Key Findings: The incidence of hyperammonemia in patients with seizures was 67.77%. Plasma ammonia levels in patients with generalized tonic–clonic (GTC) seizures were significantly higher than those in patients in the non‐GTC seizure group (median 174.5 vs. 47 μg/dl; proportion 76.5% vs. 21.1%; p < 0.001). Median plasma ammonia levels decreased spontaneously from 250 to 54 μg/dl (p < 0.00001) in an average interval of 466.79 min. GTC seizures (p < 0.0001), male gender (p < 0.0001), bicarbonate (p < 0.0001), diabetes (p = 0.0139), and alcohol‐related seizures (p = 0.0002) were significant factors associated with hyperammonemia on arrival. No significant differences related to admission rates or mortalities were found between the two groups. Significance: The presence of transient hyperammonemia in patients with seizures is significantly related to GTC seizures, male gender, bicarbonate, diabetes, and alcohol‐related seizures. The appropriate period to study ammonia levels following a seizure event is within 8 h. Because these phenomena are self‐limited, ammonia‐lowering management are not necessary. Hyperammonemia on arrival is not necessarily related to adverse outcomes.     

A 15‐year follow‐up of first unprovoked seizures: a prospective study of 200 children

Epilepsy is associated with an extended spectrum of behaviour, psychiatric problems, and learning difficulties. The aim of this study was to establish the natural history of children with first unprovoked seizures. We studied prospectively 200 children under the age of 11 years who attended hospital emergency with a first unprovoked seizure. Demographic variables, personal and family history, neurological examination, EEG, psychiatric, and cognitive and educational profiles were analysed. Patients who developed epilepsy were characterised with respect to: time to relapse, remission rate, duration of epilepsy, neuroimaging, aetiology, epileptic syndrome, and therapeutic regimen. These results were compared to data of patients who had a single seizure over a follow‐up period of 15 years. Thirty percent of children who had a first unprovoked seizure developed epilepsy. Partial seizure type was a statistically significant variable for the development of epilepsy. An EEG with epileptic abnormalities proved to be the main risk factor for recurrence. Fifteen years later, the group with epilepsy exhibited a 2.6 greater risk of psychiatric and academic comorbidities, compared to the group without epilepsy.     

Guidelines for epilepsy management in India classification of seizures and epilepsy syndromes

This article is part of the Guidelines for Epilepsy management in India. This article reviews the classification systems used for epileptic seizures and epilepsy and present the recommendations based on current evidence. At present, epilepsy is classified according to seizure type and epilepsy syndrome using the universally accepted International League Against Epilepsy (ILAE) classification of epileptic seizures and epilepsy syndromes. A multi-axial classification system incorporating ictal phenomenology, seizure type, epilepsy syndrome, etiology and impairments is being developed by the ILAE task force. The need to consider age-related epilepsy syndromes is particularly important in children with epilepsy. The correct classification of seizure type and epilepsy syndrome helps the individual with epilepsy to receive appropriate investigations, treatment, and information about the likely prognosis.     

The classification of childhood seizures and epilepsy syndromes

The classification of seizures and the epileptic syndromes is particularly relevant to those who treat children, as most syndromes are age related, with onset between the neonatal and adolescent periods. Whereas seizures are characterized by ictal behavior and EEG findings, epilepsy syndromes are defined by seizure type, etiology, age of onset, natural history, possible genetic factors, and prognosis. Limitations exist, but attempts to use these classifications typically lead to a better understanding of the patient and allow for more precise evaluation and treatment.     

Afebrile seizures associated with minor infections: comparison with febrile seizures and unprovoked seizures

This study aimed to demonstrate that afebrile seizures provoked by minor infections constitute a distinct epilepsy syndrome different from febrile seizures and unprovoked afebrile seizures. Of the children who were admitted to hospitals for their first seizure, 1170 had febrile seizures, 286 had provoked seizures, and 125 had unprovoked afebrile seizures. Children with provoked seizures were afebrile at the time of seizure but manifested definite symptoms or signs of minor infection, for example, cough, coryza, vomiting or diarrhea, normal metabolic and cerebrospinal fluid investigations, and no obvious cause for their seizures. The average follow-up was 6.1 years. The Kaplan-Meier estimate of risk at 5 years for subsequent unprovoked afebrile seizures after a first febrile seizure, provoked seizure, or unprovoked afebrile seizure was 1.6%, 5.7%, and 65.7% respectively. All differences were statistically significant (P < 0.0014). In conclusion, afebrile seizures provoked by minor illnesses constitute a distinct type of situation-related seizures, which have not been previously described. Children with provoked seizures have a much lower risk of subsequent unprovoked afebrile seizures than patients with the first afebrile seizure. Careful inquiry for symptoms of minor infections when children present with their first afebrile seizure will help determine the risk for subsequent seizures and the need for antiepileptic drugs.