Abstracts

Secondary generalized epilepsy (SGE) syndromes are typically associated with a poor prognosis, although based on our previous studies 25% enter permanent remission. We postulated that patients with SGE and convulsive status epilepticus have a more severe seizure disorder and a lower rate of remission than those without. The Nova Scotia Childhood Epilepsy Study identified all children with onset of epilepsy between 1977-85 in a population of 850,000. Children with SGE syndromes were followed up in 2004-5. Medical records and parent recall identified those with convulsive status epilepticus. Clinical course and outcome of those with and without convulsive status was compared. Convulsive status was defined as [gt]30 minutes of continuous convulsive seizures. Of the 692 children in the cohort, 79 had SGE - 11.4% of all childhood onset epilepsy. Mean age of onset was 21 months (range 1-144). Of SGE patients 26/79 (33%) had [ge]1 episode of status (10 had 1 episode, 16 had 2-100 episodes) during an average follow up for survivors of 19 [plusmn] 6.7 years (range 1.5-26 years). Etiology of epilepsy was more likely to be identified in those with status (21/26 vs. 27/53, p=0.02); however, children with status were not more likely to die during follow up than those without (5/26 vs. 4/53, p=ns). The first episode of status was within the 1.5 years of epilepsy onset in 52% and scattered between 1.5-20 years in 48%. Status did not occur in myoclonic astatic epilepsy but was equal in all other SGE syndromes [SGE otherwise unspecified 10/21 (48%), West syndrome 12/32 (38%), Lennox Gastaut 8/17 (47%) myoclonic astatic 0/9 (0%)]. Status was associated with a higher risk of frequent generalized tonic-clonic seizures ([gt]100 GTCs in 16/26 (62%) with status and 14/53 (26%) without, p[lt]0.001) and exposure to more AEDs. The status group had more major neurologic handicap prior to seizure onset (20/26 vs. 27/53 p=0.02) and less ability to walk (5/25 vs. 22/46, p=0.009). However, status was not associated with more intellectual handicap (2/26 with status were intellectually normal vs. 9/53 without, p=ns). The rate of physical injury during seizures was equal (6/24 vs. 6/39, p=ns). Terminal remission rate (seizure-free without AEDs) was markedly lower in those with status (2/26 (8%) vs. 32/53 (60%), p=0.003) and the proportion with intractable epilepsy was higher (20/26 vs. 22/53, p[lt]0.001). Convulsive status epilepticus is associated with more severe epilepsy in children with SGE. If status occurs in SGE, terminal remission is very uncommon and the chances of severe epilepsy and intractability are increased. Status in SGE is associated with higher rates of recognized etiology and major neurological handicap. We suspect that those with more severe brain disease are more prone to status and that the status itself makes little contribution to their unfavorable seizure outcome.