Covert brain complexity in the intensive care unit.
Cortex; a journal devoted to the study of the nervous system and behavior August 1, 2026 Matteo Fecchio, David R Schreier, Morgan K Cambareri et al.
This proof-of-concept report describes the use of transcranial magnetic stimulation with electroencephalography (TMS-EEG) to assess consciousness in a critically ill patient with severe brain injury in the acute stage. Standard multimodal assessments, including behavioral exams, task-based fMRI, and task-based EEG, suggested a vegetative state/unresponsive wakefulness syndrome. TMS-EEG, which directly engages corticothalamic circuits to compute the perturbational complexity index (PCI), detected signs of consciousness that these advanced evaluations missed. The authors demonstrate the feasibility of TMS-EEG as part of a multimodal protocol for consciousness assessment in the intensive care unit, potentially improving early detection and prognostication.