Absence seizures in patients with localization-related epilepsy.

We studied the clinical features of 12 patients with localization-related epilepsy (LRE) associated with absence seizures (AS). AS did not appear in any patients before partial seizures (PS) were first observed. The interval between the onset of PS and AS ranged from 1 month to 7.2 years (mean 2.11 years). The duration of AS (mean 5 months) was short compared with that of PS (mean 3.8 years). Carbamazepine (CBZ) was used in seven patients at the onset of AS. It was discontinued in five but continued in the other two. AS was initially treated with valproate in ten patients. Three of them needed additional antiepileptic drugs: clonazepam in two patients and ethosuximide in one. All patients became free from AS after treatment for AS was started, whereas PS was relatively intractable. Generalized spike-and-waves were often observed before the onset of AS. The interval between the first appearance of generalized spike-and-waves and the onset of AS ranged from 1 to 53 months (mean 20 months). AS in patients with LRE will be relatively benign and transient, and will respond well to antiepileptic drugs.