Event-related potentials reveal visual episodic memory deficits in patients with temporal lobe epilepsy.

OBJECTIVE: Temporal lobe epilepsy (TLE) patients usually suffer from impaired episodic memory (EM), but its underlying electrophysiologic mechanism and impacted cognitive performance are unclear. We aim to investigate the association between episodic memory reserve and physiological measures of memory workload in TLE patients using Event-related potentials (ERP). METHODS: A change detection task with image stimuli assesses visual episodic memory. During the memory encoding and decoding phases, the ERP signals were analyzed from twenty-nine TLE patients (twelve with left TLE patients, seventeen with TLE), and thirty healthy controls. Given that EM is a complex process involving many fundamental cognitive processes, the amplitudes and latencies of EM-related ERP (FN400, late positive potential (LPC), and late posterior negativity (LPN)), and the ERP reflecting the fundamental processes (P100, N100, P200, and P300) were calculated. Then we used a three-by-two factorial design on the ERP metrics for interaction and main effects. The correlation analysis among Wechsler Memory Scales-Chinese Revision (WMS-RC) results, behavioral data, and the ERPs was carried out. RESULTS: The TLE patients performed worse in WMS-RC and the memory task. The increased P200 and decreased P300 amplitudes were observed in the TLE patients, and LPN was abnormal in only LTLE patients. For EM-related components, differences were observed in both the LTLE and RTLE patients: the lack of the FN400 effect, the lack of the reversed LPC effect, and the reduced FN400. No significant inter-group difference was detected for the latencies of all the ERPs. Additionally, there were significant correlations among WMS-RC scores, behaviors, and some ERP amplitudes. CONCLUSIONS: The impaired EM is linked to the increased P200 and decreased P300 amplitudes. LPN seems to be sensitive to left temporal lobe dysfunction. More importantly, the abnormal old or new effects of the FN400 and LPC, and the reduced FN400 amplitude might be associated with the visual EM deficit in the TLE patients. These findings may assist in the deep understanding of the EM disorder and the evaluation of the side effects of antiepileptic drugs.

The Effect of Accelerated Continuous Theta Burst Stimulation on Weight Loss in Overweight Individuals With Schizophrenia: A Double-Blind, Randomized, Sham-Controlled Clinical Trial.

BACKGROUND AND HYPOTHESIS: Obesity is a common comorbidity in individuals with schizophrenia and is associated with poor clinical outcomes. At present, there are limited effective approaches for addressing this issue. We conducted a double-blind, randomized, sham-controlled clinical trial to investigate the efficacy of noninvasive magnetic stimulation techniques in reducing obesity in individuals with schizophrenia. STUDY DESIGN: Forty overweight individuals with schizophrenia were recruited and randomly assigned to receive either the active or sham intervention. The active group received 50 accelerated continuous theta burst stimulation (cTBS) sessions over the left primary motor area (M1), while the sham group received sham stimulation. The primary outcomes were the change in body weight and body mass index (BMI), and the secondary outcomes were the psychiatric symptoms, eating behavior scales, metabolic measures, and electrophysiological to food picture stimuli. STUDY RESULTS: The study demonstrated a significant decrease in body weight and BMI after the intervention selectively in the active group (mean = -1.33 kg, P = .002), and this improvement remained at the 1-month follow-up (mean = -2.02 kg, P = .008). The score on the Barratt Impulsivity Scale (mean = -1.78, P = 0.036) decreased in the active group and mediated the effect of accelerated cTBS on body weight. In the food picture cue electroencephalograph task, the late positive potential component, which is related to motivated attention and emotional processing, decreased in frontal brain regions and increased in posterior regions after the active intervention. CONCLUSIONS: The accelerated cTBS may offer a promising approach for treating obesity in individuals with schizophrenia. Further research with a larger sample size or individualized stimulation protocol should be promising. TRIAL REGISTRATION: Clinical trial registered with clinicaltrials.gov (NCT05086133).