Efficacy of intravenous immunoglobulin in Landau-Kleffner syndrome.

We administered 2 gm/kg of intravenous gamma globulin (IVIG) to each of five consecutive patients with Landau-Kleffner syndrome, over 4 days. We compared the 1-month baseline to that following IVIG using a severity score assessing speech, comprehension, behavior, seizures, and electroencephalography. There was a significant drop in this score after IVIG (P = 0.025). Two patients had a dramatic response to IVIG, with complete resolution of symptoms. This finding suggests that IVIG has at least some efficacy for the therapy of Landau-Kleffner syndrome.