Electroencephalography demonstrating rhythmic frontocentral theta activity in a patient with Rett syndrome

Rhythmic frontocentral theta in a patient with Rett syndrome.
(A) Electroencephalography demonstrated a prominent 50 to 100 microvolts, 4 to 5 Hz rhythmic, fluctuating central theta rhythm (asterisk) during wakefulness.
(B) After tactile stimulation (line), a blocking phenomenon occurred (arrow), during which the central theta rhythm abated. All data are presented in longitudinal bipolar montage, sensitivity 7 microvolts/mm.