Abstracts

RATIONALE: Prolonged convulsive seizures are a common neurological emergency and a potential cause for neuronal damage and functional sequelae. This study explores the role of various background factors for possible neurological sequelae of convulsive seizures lasting over five minutes in children.
METHODS: The subjects of this study were all those children ([lt]16 years) who had been admitted into the Pediatric Intensive Care Unit of Tampere University Hospital, Finland, between 1993 and 1999 due to convulsive seizures lasting more than 5 minutes. Patients were followed up after this episode on individual basis and the mean follow-up time was 2.1 years (range 0.1 to 7.7 years). All data of the initial seizure episode and clinical follow up was analyzed retrospectively through medical charts and records.
RESULTS: There were 279 separate seizure episodes lasting [gt]5 minutes in 186 children (mean 4.4 years; range 1 month to 15.25 years). Previously diagnosed epilepsy was present in 80 cases (28.7%) and other neurological abnormality in 112 cases (39.1%). The etiology of the acute seizure episode was idiopathic in 26.5%, febrile in 42.3%, remote symptomatic in 27.6% and acute symptomatic in 5.7% of the cases. The mean duration of the prolonged seizure episode in the study group was 42.5 minutes, and 160(57.6%) of these episodes had lasted more than 30 minutes (=convulsive status epilepticus). The mean duration was correlated with the etiology: it was the shortest in the febrile group (35.4 minutes) and the longest in the acute symptomatic group (88.6 minutes) (p[lt]0.001). 10% of the episodes had resolved spontaneously, and rectal or iv. benzodiazepines had aborted additional 58%, other iv. anticonvulsants (phenobarbital, phenytoin) were needed in 25% of benzodiazepine-refractory cases and barbiturate anaesthesia had to be used to abort the still continuing convulsions in the remaining 7%. The main result was that there were no deaths directly related to these acute prolonged seizure episodes. The most common sequelae was recurrence of seizures (=onset of epilepsy) in 40 children (22%), the etiology of the initial seizure episode being idiopathic in most of these cases (60%). Major, permanent neurological sequelae was noted only in four patients (2.2%, mean seizure duration 16 min.), three of them had acute symptomatic etiology. Minor, nonpermanent sequelae occured in six patients (3.2%, mean seizure duration 38 min.), the etiology being febrile in five of them.
CONCLUSIONS: Permanent neurological sequelae in children after prolonged convulsions seems to be rare and related more to etiological factors than duration of a single seizure episode. The possible role of acute seizures in the evolution of active epilepsy in children remains obscure.
Support: Arvo and Lea Ylppö Foundation