Electrophysiological Changes Related to Childhood Trauma in Patients with Major Depressive Disorder: An Event-related Potential Study

A Comparative Investigation of Functional Connectivity Utilizing Electroencephalography in Insomnia Patients with and without Restless Leg Syndrome

Objective

The current study aimed to identify distinctive functional brain connectivity characteristics that differentiate patients with restless legs syndrome (RLS) from those with primary insomnia.

Methods

Quantitative electroencephalography (QEEG) was employed to analyze connectivity matrices using the phaselocking value technique. A total of 107 patients with RLS (RLS group) and 17 patients with insomnia without RLS (primary insomnia group) were included in the study. Demographic variables were compared using t tests and chi-square tests, while differences in connectivity were examined through multiple analyses of covariance. Correlation analysis was conducted to explore the relationship between connectivity and the severity of RLS.

Results

The results indicated significant differences in the primary somatosensory cortex (F = 4.377, r = 0.039), primary visual cortex (F = 4.215, r = 0.042), and anterior prefrontal cortex (F = 5.439, r = 0.021) between the RLS and primary insomnia groups. Furthermore, the connectivity of the sensory cortex, including the primary somatosensory cortex (r = -0.247, p = 0.014), sensory association cortex (r = -0.238, p = 0.028), retrosplenial region (r = -0.302, p = 0.002), angular gyrus (r = -0.258, p = 0.008), supramarginal gyrus (r = -0.230, p = 0.020), primary visual cortex (r = -0.275, p = 0.005) and secondary visual cortex (r = -0.226, p = 0.025) exhibited an inverse association with RLS symptom severity.

Conclusion

The prefrontal cortex, primary somatosensory cortex, and visual cortex showed potential as diagnostic biomarkers for distinguishing RLS from primary insomnia. These findings indicate that QEEG-based functional connectivity analysis shows promise as a valuable diagnostic tool for RLS and provides insights into its underlying mechanisms. Further research is needed to explore this aspect further.

The cognitive tasks and event-related potentials associated childhood adversity: A systematic review

In this systematic review, 18 articles met inclusion criteria to be qualitatively analyzed for converging evidence of brain activity, measured using event-related potential (ERP), related to retrospectively reported childhood adversity/trauma. Using the PRISMA guidelines for systematic reviews, 917 articles were assessed for inclusion and were filtered using study parameters. The most common ERP components listed in the literature were P100, N170, N200, P200, P300, ERN, and LPP. We discuss levels of evidence for changed brain activity, each ERP component, and the tasks used to evoke them. The Childhood Trauma Questionnaire was found to be the most commonly cited measure. We note the need to assess the duration and intensity of childhood adversity/trauma measurements in the strengths and limitations of the reported childhood adversity/trauma measurements. No concrete converging evidence was found to support a relationship between ERP-measured brain activity and retrospectively reported childhood adversity/trauma. Thus, a discussion of limitations and future directions for this field of research is presented.