Figure 1: Case 1. Brain computed tomography (CT) and magnetic resonance imaging (MRI) on admission. Brain CT showed no acute cerebral bleeding (a). Brain MRI showed no acute cerebral infarction (b). Electroencephalography after admission showed repetition of intermittent high-amplitude irregular slow waves in the right frontal lobe (c). *Lead placement: 1, left frontal pole (Fp1); 2, left frontal (F3); 3, left central (C3); 4, left parietal (P3); 5, left occipital (O1); 6, right frontal pole (Fp2); 7, right frontal (F4); 8, right central (C4); 9, right parietal (P4); 10, right occipital (O2); 11, left mid temporal (T3); 12, right mid temporal (T4).