To the Editor.
—Paquier et al1 made an excellent review of the recent advances in the understanding of the Landau-Kleffner syndrome (LKS). There is little agreement on the limits, mechanism, or treatment of this particular condition.2 Landau-Kleffner syndrome can easily be differentiated from postictal aphasia (of short duration) and other, primary or permanent, forms of childhood language disorders. However, particular problems are posed by the electroencephalographic (EEG)-clinical correlations. A few points should be stressed:1. There is no correlation whatsoever between epilepsy (understood as a clinical phenomenon, which it is, and not as an abnormal EEG) and LKS; most patients with both LKS and seizures have a very mild form of epilepsy and readily respond to antiepileptic drug therapy.2. There is, indeed, a correlation between EEG abnormalities and the speech disorder, although both may fluctuate "out of phase" at some point; there are no clinical reports with
Genton P, Guerrini R. What Differentiates Landau-Kleffner Syndrome From the Syndrome of Continuous Spikes and Waves During Slow Sleep?. Arch Neurol. 1993;50(10):1008–1009. doi:10.1001/archneur.1993.00540100009006