title: Etiology and Long-Term Outcomes of Late-Onset Infantile Spasms.
abstract: OBJECTIVE
  The purpose of the study was to evaluate the etiology and long-term outcomes of late-onset epileptic spasms (LOS).
  
  
  METHODS
  This is a retrospective analysis of all consecutive patients seen at our center with onset of clusters of epileptic spasms between 1 and 3 years of age in 1995 through 2005.
  
  
  RESULTS
  Overall, 17 children with LOS were identified. Overall, 14 children (82%) had structural etiology. Six patients received resective surgical treatment. Five had focal cortical dysplasia type 1 (FCD1) histology (29% of all the patients). Overall, 16 children were followed for 2 to 18 years. At the latest follow-up, seizure freedom was observed in 67% of the operated and in 50% of the nonoperated patients. Normal cognition or only mild mental deficiency was observed in nine patients (56%), of whom eight were seizure-free. All patients with intractable spasms had a severe mental deficiency.
  
  
  CONCLUSIONS
  The overall cognitive outcome of LOS was more favorable than in the previous reports and was associated with seizure freedom. FCD1 is a frequent etiology for LOS and the cognitive outcome of patients with FCD1 seemed to be favorable.
authors.affiliation: Epilepsy Unit, Department of Pediatric Neurology, Helsinki University Hospital, Helsinki, Finland.
authors.forename: Liisa
authors.initials: L
authors.lastname: Metsähonkala
authors.affiliation: Epilepsy Unit, Department of Pediatric Neurology, Helsinki University Hospital, Helsinki, Finland.
authors.forename: Eija
authors.initials: E
authors.lastname: Gaily
authors.affiliation: Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Valanne
authors.affiliation: Department of Neurosurgery, Helsinki University Hospital, Helsinki, Finland.
authors.forename: Göran
authors.initials: G
authors.lastname: Blomstedt
mesh_terms: D000293:Adolescent; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D000067562:Late Onset Disorders / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications*; D012189:Retrospective Studies; D013036:Spasms, Infantile / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D055815:Young Adult