Abstracts

Epilepsy Monitoring units (EMUs) have become increasingly important in the diagnosis and management of epilepsy. In spite of this role, very limited information is available about the distribution of epilepsy syndromes in children with intractable epilepsy, which is expected to be rather different from the general epilepsy population. In this study, we analyzed the distribution of epilepsy syndromes in children with intractable epilepsy who were admitted to an EMU. A total of 1430 patients were admitted to the EMU at Montefiore Medical Center between January 1991 and December 1998. Among them, 859 patients were under 12 years old of which 483 patients were children with intractable epilepsy admitted for diagnostic and/or therapeutic purposes. These 483 children are the subject of this retrospective chart review. Children who were admitted for the first time for diagnostic purposes without clear history of clinical seizures were excluded from the study. Classification of seizure types and epilepsy syndromes were made using an algorithm based on the ILAE classification. To date, we have reviewed 150 cases. The etiology of epilepsy syndromes was idiopathic in 14 (9%), cryptogenic in 42 (28%), and remote symptomatic in 94 (62 %). Epilepsy syndromes were generalized in 83 (55%) children, localization related in 51 (34%), and undetermined whether focal or generalized in 15 (10%). Among children with generalized epilepsy syndromes, those of cryptogenic or symptomatic etiology (infantile spasms, Lennox-Gastaut and myoclonic astatic epilepsy) accounted for the majority of cases (80%). In children with localization related epilepsy, the majority (85%) met the criteria for symptomatic epilepsy by virtue of either localization or etiology. Of the 150 children, 75(49%) were either developmentally delayed or had abnormalities on their neurological examination. Neurodevelopmental abnormalities were present in 59 (71%) of 83 children with generalized epilepsy syndromes compared with 16 (31%) of the 51 children with partial epilepsy (p[lt]0.0001). Thirty-four (22%) children had multiple admissions including 18 (22%) with generalized epilepsy and 11 (22%) with localization related epilepsy. The distribution of epilepsy syndromes in children admitted to EMUs is skewed towards nonidiopathic generalized epilepsy syndromes and symptomatic localization related epilepsy. A high proportion of children, particularly those with generalized epilepsy are neurologically abnormal. The remainder of this cohort is being reviewed. Follow up study is underway to assess the long-term seizure outcomes, neurodevelopmental status and school progress of these children.