Electroclinical characteristics of Landau-Kleffner syndrome
The study aimed at investigating epileptic attack's semiology and other electroclinical characteristics in Landau-Kleffner syndrome as well as therapeutic efficacy. Six patients with Landau--Kleffner syndrome, 5 boys, 1 girl, aged 6-10 years, mean age 7.5 years, have been analyzed. Epileptic attacks were observed only in 3 patients with debut at the age of 2.5-6 years (mean 4 years). In 50% of the cases, the attacks were not detected. The types of epileptic attacks were specified as follows: atypical absences--3 patients; pharyngo-oral--2; secondary generalized--2; atonic falls--1; hemiconvulsive--1. In routine EEG study, regional epileptiform activity was observed in all the patients, being localized in central temporal (3 cases), posterior temporal (1) and fronto-temporal (1) leads. In 3 cases (50%), diffusive epiactivity was also detected. During sleep, emergence of prolonged diffuse epiactivity was revealed for all the patients, with appearance of electrical status epilepticus during slow sleep in 50%. Valproates in dosage 30-60 mg/kg daily were highly effective for stopping epileptic seizures. Significant improvement of speech functions was observed only if antiepileptics sulthiame (ospolot) or clobasam (frizium) were used in addition to basic therapy. Clobasam in dosage 0.5-0.75 mg/kg daily was the most efficient in blockade of EEG diffuse epileptiform activity, reduction of aphasia symptoms and behavior improvement.