Recurrence after a First Unprovoked Cryptogenic/Idiopathic Seizure in Children: A Prospective Study from São Paulo, Brazil

Abstract

Summary:Purpose: To evaluate the recurrence risk after a first unprovoked seizure in a large population of children and adolescents of a developing country.Methods: This prospective study was conducted at two tertiary hospitals, between September 1989 and August 1998. Children were enrolled if they had a first unprovoked cryptogenic/idiopathic seizure and maximal interval to the enrollment ≤90 days. EEG and computed tomography (CT) were performed in most patients. Potential predictors of recurrence were compared by using the Cox proportional hazards model in univariate and multivariate analyses. Survival analysis was performed by using the Kaplan-Meier curves.Results: Two hundred thirteen children were included. Recurrence occurred in 34% of the patients, and mean time for recurrence was 12 months. Statistical analysis showed significance for seizure recurrence only for patients with abnormal EEGs. CT was performed in 182 patients, and abnormalities were found in 9.5%. Small calcifications were the most frequent finding, and this was not a predictor for recurrence.Conclusions: The risk of recurrence after a first unprovoked seizure in children from a developing country is similar to that found in developed countries. An abnormal EEG is a risk factor for seizure recurrence in children with a cryptogenic/idiopathic seizure. Calcifications on CT do not increase the risk of recurrence. Key Words: Unprovoked seizure-Children-Recurrence rate-Risk factorsCalcifications.The recurrence rate after a first unprovoked seizure varies widely depending mainly on the design of the study and the inclusion criteria of the subjects (1-13). Risks of recurrence vary from 26 to 71%. Retrospective studies usually show higher recurrence rates than do prospective studies.Most studies that address this issue have been conducted in developed countries. The aim of this study was to evaluate the recurrence risk after a first unprovoked seizure in a large population of children and adolescents of a developing country and examine whether the outcome of first nonsymptomatic seizures in Brazil is similar to that seen in other countries. METHODSThis prospective study was conducted at the Pediatric Epilepsy Clinics of two tertiary hospitals,

Epilepsy in the developing world

“…In DCs, after a fi rst unprovoked seizure, the risk of recurrence is 33% to 37%, which is similar to that among developed countries [25][26][27]. Studies from DCs show that epilepsy secondary to underlying structural causes [26] or with an abnormal electroencephalogram confers the worst prognosis [27].…”

Determination of risk factors associated with seizure relapse after antiepileptic drug withdrawal

“…the number of seizures before treatment, the total number of seizures, the time period from the initiation of treatment until the convulsions being under control, the duration of discontinuation and seizure relapse rates after AED withdrawal [5,14,22]. It has been reported that the overall seizure relapse rate was 23-71% in patients who did not receive any treatment after the first seizure and seizure relapse rates were higher in patients who had abnormal EEG findings and symptomatic epilepsy [23][24][25][26][27][28]. The relation between age at onset of epilepsy and seizure relapse rates have been investigated in several studies with contradictory results [10,11,29].…”

Risk of seizure recurrence in patients of new-onset partial seizure having a solitary cysticercus granuloma of brain or normal neuroimaging

“…The diagnosis of a patient seizures was based on the International League against Epilepsy Classification [8]. A family history of seizures was defined as a history of an unprovoked seizure or seizures in parents or siblings [9]. Serial seizures were defined as multiple seizures within 24 h [10].…”

“…Persons with status epilepticus or clusters of seizures (two or more) in the same 24-h period were considered to have had a single seizure [15]. Status epilepticus was defined as a seizure lasting N30 min or as a series of seizures, without regaining consciousness between them, lasting N30 min [9]. Patients having three or more seizure episodes were classified as multiple seizure recurrences.…”