Predicting risk of post-stroke delirium using transcranial magnetic stimulation-evoked EEG responses (DELIRISK)

• Applicant: Privatdozentin Dr. Annerose Mengel
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology ; Cognitive, Systems and Behavioural Neurobiology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 566383634

Delirium is an acute neuropsychiatric disorder, which results in a fluctuating disturbance in attention, awareness, and cognition. Approximately one in four stroke patients develops delirium within the first seven days after stroke onset, making it a very common and, in fact, severe complication after stroke. Post-stroke delirium (PSD) is associated with serious outcomes including cognitive decline, longer periods of hospitalization and increased mortality. Diagnosis is currently limited to clinical screening tools, e.g., the Intensive Care Delirium Screening Checklist (ICDSC), and confirmation by DSM-V criteria. To date no objective biomarkers exist for the diagnosis. Transcranial magnetic stimulation (TMS)-EEG is a relatively novel technique, which became available with advanced TMS-compatible EEG amplifiers that avoid a large TMS-induced artifact in the EEG signal. It provides a way for directly probing both local and widespread changes in brain neurophysiology, through the recording of TMS-evoked potentials and TMS-induced cortical oscillations Our study group has recently conducted a pilot study using resting-state EEG and TMS-EEG for estimating delirium risk in the acute phase after stroke. In summary, our pilot study showed that acute stroke patients at risk for PSD present abnormal brain physiology (which can be detected by resting-state EEG and TMS-EEG) already prior to delirium onset. The increased low-frequency activity, decreased high-frequency activity and decreased spatio-temporal complexity of cortical reactivity are strongly associated with delirium development. Theses abnormalities might become biomarkers to predict delirium onset at a very early stage and, therefore, help to guide prevention and therapy for patients at risk for PSD. Our pilot work has been published in the meantime as a cover study in Clinical Neurophysiology and was highlighted by an Editorial from Prof. Marcello Massimini. However, due to our small sample size, conduction of an adequately powered larger confirmation study is necessary to obtain convincing and more comprehensive knowledge about PSD vulnerability and its development. We will investigate more EEG and TMS-EEG features and build a machine learning model to integrate the complex data into a tool that will be applicable in daily practice. We expect that this project will help to identify patients at risk of PSD to improve PSD prevention and therapy.

• DFG Programme: Research Grants
• Co-Investigators: Professorin Dr. Katharina Feil; Dr. Robert Fleischmann