Abstracts

Epilepsy surgery is an established treatment for many patients with refractory focal epilepsy, and is not employed for treatment of primary generalized epilepsy. Yet, both conditions may coexist in the same patient and thereby cause unique diagnostic and therapeutic challenges. Only few previous case reports have addressed this issue. Our aim is to review the clinical, electrograghic, radiological, and pathological findings of patients with coexistent epileptic syndromes evaluated in our institution within the last 10 years.
3009 patients were admitted to the epilepsy monitoring units in the Cleveland Clinic between 1992 to 2002. Among those, a database computer search identified 185 patients who had either (1) generalized and focal seizures, or (2) generalized seizures with an interictal focus, or (3) focal seizures with interictal generalized spike and/or sharp wave activity. Exclusion criteria were: (1) age [lt] 10 or [gt]60 years old; (2) obvious secondary bilateral synchrony, independently occurring extratemporal spikes, multiple independent spike foci, and/or generalized discharges with consistent or prominent lateralization on EEG; (3) a clinically progressive cerebral lesion such as a tumor; (4) focal neurological deficits, developmental delay or mental retardation.
Only seven patients met all criteria. Two (29%) were men. Mean age was 26 years (range 15 to 52yo). Four patients had a history of febrile seizures; an equal number had a positive family history of epilepsy. At the time of evaluation, mean duration of the generalized epilepsy syndrome was 11 years, and of the focal epilepsy syndrome 18 years. Among the seven patients, four had video EEG documentation of both focal and generalized seizures. Three patients had only their focal seizures recorded, but had strong interictal findings supportive of a coexistent generalized epilepsy. Hippocampal atrophy was present on MRI in five patients, and hippocampal dysplasia in two. Five patients had PET imaging with hypometabolism in areas corresponding to the ictal onset on EEG. Interictally, 1%-86% of the spikes/sharp waves were regional, while 14%-99% were generalized in six out of the seven cases identified. One patient had no evidence of her generalized epilepsy until after right temporal lobectomy for the treatment of intractable focal epilepsy when valproate was discontinued. Four patients underwent epilepsy surgery with pathological confirmation of hippocampal sclerosis in all. Two are seizure free on monotherapy; two are lost to follow-up.
We found a 0.2% prevalence of coexistent focal and primary generalized epilepsy in patients admitted to the epilepsy monitoring units over 10 years . Febrile seizures and a positive family history of epilepsy were common. In patients with coexistent epilepsy syndromes, even if most of the interictal discharges were generalized, good seizure control was achieved if the focal epileptogenic zone was surgically resected.