Rolandic epilepsy: tap-indiced spikes seen in a girl in remission

(A) Spontaneous high-amplitude centrotemporal spikes (in fact, these are central spikes) occur independently on the right and left, and are markedly exaggerated during natural sleep. (B) Typical morphology and polarity of centrotemporal spikes in laplacian montage. (C) Giant spikes are evoked by tapping fingers or toes. Note that their location corresponds to the location of the activating stimulus (black arrows). (D) Giant somatosensory spikes from another patient are evoked by electrical stimulation of the right thumb (onset at red arrow). Peak latency of the somatosensory evoked spike is 58 ms. (Used with permission from: Panayiotopoulos CP. A clinical guide to epileptic syndromes and their treatment. Revised 2nd edition. London: Springer, 2010.)