Prolonged recovery of consciousness in children following symptomatic epileptic seizures

There is little published data on the duration of depressed consciousness following epileptic seizures. A prolonged recovery time may be a symptom of underlying brain pathology. This prospective paediatric cohort study investigates whether recovery is prolonged following symptomatic seizures.

Children aged 1-16 years, who had a witnessed seizure in which consciousness was impaired, were recruited. One hundred and twenty eight children (158 seizures) were studied. Seizure aetiology was classified as febrile, idiopathic, remote symptomatic, acute symptomatic and acute on remote symptomatic. At least hourly Paediatric Coma Scale recordings were used to assess recovery time.

Recovery time was longest for children with acute on remote symptomatic seizures (4.0 h, range 0.89-10.5), followed by those with acute symptomatic seizures (1.94 h, range 0-35.27), remote symptomatic seizures (1.5h, range 0.07-85.5) and idiopathic seizures (0.83 h, range 0.07-13.13). Children with febrile seizures recovered the quickest (0.3h, range 0.05-9). Recovery time was significantly longer (p<0.001, CI 1.96-5.38) following seizures for which rescue antiepileptic drugs were administered compared to those for which it was not. Age, sex, type and duration of seizure did not independently affect recovery time.

Symptomatic seizures take longer to recover than seizures of other aetiologies. It is recommended that a febrile child who presents with a seizure, who has not fully recovered within 30 min, should be investigated for an acute symptomatic aetiology. A high index of suspicion is also needed if children with apparent idiopathic seizures have not fully recovered within 1.5h.