case_images: PMC10917932_01
case_images: Experimental setup. The stimulator output signal during AM-tACS is illustrated with amplitude of a carrier signal (120 Hz) modulated at 15 Hz of a signal envelop (A). The electrodes (5 x 5 cm) were placed on F7 and F8 in the sham and real conditions, and on F7 and P5 in the control condition (B). The order of the interventions is illustrated in the short-term and long-term interventions (C, D).
case_images: fnhum-18-1297683-g0001.jpg
case_images: PMC10917932_01_fnhum-18-1297683-g0001.jpg
case_images: F1
case_images: We conducted three types of interventions to examine the effect of AM-tACS according to an N-of-1 study design: (1) AM-tACS with 120 Hz frequency of sinusoidal carrier waves with 15 Hz of sinusoidal amplitude modulation, a peak-to-peak amplitude of 3 mA (-1.5-1.5 mA) and trough amplitudes of +- 0.3 mA (Figure 1A) on the Broca's area [centering the 5 x 5 cm2 electrode on F7 according to the international 10-20 electroencephalography (EEG) system] and on the homotopic region of the right hemisphere (centering the 5 x 5 cm2 electrode on F8; real condition), (2) sham AM-tACS with only 10 cycles of 15 Hz amplitude modulation of AM-tACS given on the same regions with the real condition (sham condition), and (3) AM-tACS with the Broca's area and the left parietal area using the same stimulation parameter with the real condition (control condition) by using Nurostym tES (Neuro Device Group S.A., Warsaw, Poland; Figure 1B). The interval between sessions was over 1 h, and the control condition was performed 1 day after the real and sham conditions because of patient fatigue (Figure 1C). For the long-term intervention, we performed 10 sessions of sham and real conditions (one session per day, 2 days per week for 5 weeks) with the interval of 1 month (Figure 1D).