S. Shinnar et al., THE RISK OF SEIZURE RECURRENCE AFTER A FIRST UNPROVOKED AFEBRILE SEIZURE IN CHILDHOOD - AN EXTENDED FOLLOW-UP, Pediatrics, 98(2), 1996, pp. 216-225
Objective. To assess the long-term recurrence risks after a first unpr
ovoked seizure in childhood. Methods. In a prospective study, 407 chil
dren who presented with a first unprovoked seizure were then followed
for a mean of 6.3 years from the time of first seizure. Results. One h
undred seventy-one children (42%) experienced subsequent seizures. The
cumulative risk of seizure recurrence was 29%, 37%, 42%, and 44% at 1
, 2, 5, and 8 years, respectively. The median time to recurrence was 5
.7 months, with 53% of recurrences occurring within 6 months, 69% with
in 1 year, and 88% within 2 years. Only 5 recurrences (3%) occurred af
ter 5 years. On multivariable analysis, risk factors for seizure recur
rence included a remote symptomatic etiology, an abnormal electroencep
halogram (EEG), a seizure occurring while asleep, a history of prior f
ebrile seizures, and Todd's paresis. In cryptogenic cases, the risk fa
ctors were an abnormal EEG and an initial seizure during sleep. In rem
ote symptomatic cases, risk factors were a history of prior febrile se
izures and age of onset younger than 3 years. Risk factors for late re
currences (after 2 years) were etiology, an abnormal EEG, and prior fe
brile seizures in the overall group and an abnormal EEG in the cryptog
enic group. These are similar to the risk factors for early recurrence
. Conclusions. The majority of children with a first unprovoked seizur
e will not have recurrences. Children with cryptogenic first seizures
and a normal EEG whose initial seizure occurs while awake have a parti
cularly favorable prognosis, with a 5-year recurrence risk of only 21%
. Late recurrences do occur but are uncommon.