Pathophysiological relevance of EEG slowing: An EEG/fMRI/MR-spectroscopy study in patients with borderline personality disorder and autoimmune psychosis

• Applicants: Professor Dr. Dominique Endres; Dr. Bernd Feige; Professor Dr. Ludger Tebartz van Elst, Ph.D.
• Subject Area: Clinical Psychiatry, Psychotherapy, Child and Adolescent Psychiatry
• Term: from 2019 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 419859038

Patients with borderline personality disorder (BPD) and autoimmune psychosis (AP) show a high prevalence of electroencephalography (EEG) slowing. In particular, these patients display identifiable, generalized, and intermittent rhythmic delta- and theta activity (IRDA and IRTA). In earlier studies, we found these phenomena in 15% of patients with BPD. EEG slowing such as IRDAs/IRTAs was found even more frequently in patients with autoimmune psychoses (in 80-90%). The exact pathogenetic-pathophysiological and differential diagnostic importance of IRDAs/IRTAs is still unclear. They have been interpreted as paraepileptic components in different neuropsychiatric disorders and can be an expression of neuronal network instability. With new functional and neurochemical imaging methods, further scientific insights are possible. In preliminary investigations, we were able to show valid localization of the generator areas of IRDAs/IRTAs with simultaneous EEG/fMRI imaging. In the planned project, simultaneous resting state EEG- fMRI imaging will be used to show hemodynamic correlates of IRDAs/IRTAs in patients with BPD and AP. In volumetric and MR-spectroscopic (MRS) measurements, the generator areas should be analyzed regarding their volume and neurochemical integrity and compared with a control group. The aim of this study is to create a better trans-diagnostic pathophysiological classification of these EEG phenomena. Therefore, the pathophysiology of BPD and AP should be clarified in the patient group with these EEG alterations. For the first time in patients with BPD and AP, we plan to use the whole brain MRS to quantify GABA and glutamate concentrations. The study is clinically relevant because anticonvulsants (e.g., the GABA agonist and NMDA antagonist valproate) were already used off-label in patients with BPD and AP. This study should be able to provide explanatory approaches for the partially successful use of such anticonvulsants.

• DFG Programme: Research Grants