Abstracts

RATIONALE:_Epileptic spasms occur rarely, are similar electroclinically to infantile spasms, and are known to persist beyond infancy. They are defined by brief axial flexion/extension jerks (often occurring in clusters) that are associated with a slow-wave transient, blunted sharp wave, with or without an electrodecremental response on EEG. Spasms often do not respond to anticonvulsant medications. Our aim was to determine whether the clinical and/or EEG features of epileptic spasms change with age. METHODS:_Retrospective chart and time-locked video-EEG review of patients evaluated at the Children's Hospital and Regional Medical Center (Seattle) between 1996-1999 who met clinical criteria for epileptic spasms. Included were patients whose spasms persisted beyond the second year of life. RESULTS:_Epileptic spasms were identified in 24 patients (age range: 2.5 to 17 years, mean = 8.2). Seizure frequency ranged from 1-200 (mean = 37) per day, and complete seizure control was uncommon (2 patients were seizure-free on valproic acid, 1 on lamotrigine, 1 on lamotrigine and carbamazepine following temporal lobe resection of a dysplastic lesion). The EEG background was slow in 17 cases; in 5 of the remaining 7 cases, normal or mildly slow posterior background activity correlated with mild cognitive dysfunction. The ictal EEGs showed slow-wave transients followed by attenuation in 22 cases; in 5 of these cases, paroxysmal fast activity was superimposed on the slow transients. In the remaining two cases, spasms were accompanied by a blunted sharp wave or an isolated electrodecremental response. CONCLUSIONS: Epileptic spasms persisting beyond the second year of life are characterized by relatively stable ictal EEG correlates and clinical semiology. Most patients with this epileptic condition are severely impaired. However, normal or mildly slow EEG background activity appears to be associated with a better outcome.