Abstracts

To update previous work on age-related differences in spontaneous epilepsy after amygdala kindling in cats. Amygdala kindled seizure development and the post-kindling course is described in 58 cats (29 males and 29 females), including 40 preadolescents between 2.5 and 6.5 months of age and 18 adults [ge] 1year of age at the beginning of kindling The results confirm and extend previous findings, as follows: 1) Young animals are far more likely than adults to exhibit spontaneous epilepsy, indexed by seizures that occur [ge] 1 h after stimulus-evoked seizures; 2) The youngest animals ([le]5.0 months, n=30) exhibit accelerated kindling rates (fewest elicited afterdischarges or ADs to the first generalized tonic-clonic convulsion or GTC) and rapid post-kindling onset of multifocal spontaneous epilepsy with a catastrophic clinical course. The profile includes a variety of EEG and/or clinical seizure manifestations and a progressive increase in the number and density of convulsive seizure clusters. Behavioral sequelae accompany seizure clusters and range from sensory or motor deficits (visual agnosia, sensory hypersensitivity, atonic episodes, restricted mobility) to social isolation and placidity. Developmental deterioration with spontaneous epilepsy need not be gender-related, rarely involves anatomical localization of kindling site and is substantially enhanced by recurrent or recent evoked seizures early in the post-kindling course. The post-kindling progression can be stopped or minimized by suspension of evoked seizure trials and/or by management of frequent spontaneous convulsions ([gt] 1 per h) with nembutal. The findings suggested different factors in the onset vs. maintenance of spontaneous epilepsy at different ages and a favorable prognosis for the young following early detection and intervention. (Supported by Department of Veterans Affairs)