Abstract
OBJECTIVE: Exploring whether ultra-brief pulse electroconvulsive therapy (ECT) reduces the occurrence of postoperative delirium in patients with schizophrenia (SCZ), and its effects on cholinesterase, inflammatory markers, and hippocampal neural metabolites. METHODS: From August 2022 to August 2023, inpatients at the Affiliated Brain Hospital of Nanjing Medical University diagnosed with SCZ according to the International Statistical Classification of Diseases and Related Health Problems (Tenth Edition ICD-10) and aged 18-55 years were studied. Patients were randomly divided into ultra-brief pulse (UBP) and brief pulse (BP) groups, receiving ultra-brief pulse ECT (pulse width 0.25 ms) or brief pulse ECT (pulse width 1.0 ms). Assessments were conducted before and 24 h after ECT sessions, including evaluations of delirium, psychiatric symptoms, magnetic resonance spectroscopy (MRS) for hippocampal metabolites, and serum markers. Delirium was assessed using the Richmond Agitation-Sedation Scale (RASS) and the Confusion Assessment Method for the Intensive Care Unit (ICU-CAM). MRS measured changes in hippocampal metabolites, including N-acetyl-aspartate (NAA), creatinine (Cr), myo-inositol (MI), and choline (Cho). Serum markers included twelve cytokines, C-reactive protein (CRP), and cholinesterase (ChE). Statistical analyses used chi-square tests and independent sample t-tests. RESULTS: No significant differences were found between the UBP and BP groups in baseline demographic and clinical data, cholinesterase levels, inflammatory markers, hippocampal spectra, ECT sessions, and BPRS scores post-treatment. However, the incidence of delirium was significantly different between UBP and BP groups (χ(2) = 3.49, p = 0.046), with the BP group having a higher incidence of delirium. Post-treatment, cholinesterase levels in the UBP group were significantly higher than those in the BP group (t = 0.52, p < 0.001). Levels of CRP, IL-6, IL-8, IL-10, IL-1β, and TNF-α were significantly lower in the UBP group compared to the BP group. Right hippocampal NAA/Cr and left hippocampal NAA/MI levels were significantly lower in the UBP group than in the BP group post-treatment. CONCLUSION: Compared with BP ECT, UBP ECT may reduce the incidence of delirium post-treatment in SCZ without a significant difference in efficacy. The higher cholinesterase levels in the UBP group suggest that UBP ECT may reduce neuronal asynchronous depolarization, cholinergic disorder, and pro-inflammatory responses, thereby reducing the impact on delirium. These findings provide partial scientific evidence for elucidating the mechanisms underlying ECT.