Measuring Brain Complexity to Detect and Predict Recovery of Consciousness in the ICU

Measuring Brain Complexity to Detect and Predict Recovery of Consciousness in the ICU (COMPASS)

Disorders of consciousness (DoC) caused by severe brain injury affect millions of people worldwide each year. A patient's level of consciousness in the intensive care unit (ICU) significantly impacts the recovery from disability and is a primary determinant of family decisions about withdrawal of life-sustaining therapy (WLST). However, reliable assessment of consciousness in the ICU remains elusive. Transcranial magnetic stimulation-electroencephalography (TMS-EEG) is a tool that has shown the best performance in detecting signs of consciousness in patients with chronic DoC. The goals of this prospective, observational study are to demonstrate the diagnostic performance and prognostic utility of TMS-EEG in the ICU setting.

Disorders of consciousness (DoC) caused by severe brain injury affect millions of people worldwide each year. A patient's level of consciousness in the intensive care unit (ICU) significantly influences the recovery from disability and may affect family decisions about withdrawal of life-sustaining therapy (WLST). Transcranial magnetic stimulation-electroencephalography (TMS-EEG) has shown the best performance in detecting signs of consciousness in patients with chronic DoC. The goals of this multi-center observational study are to demonstrate the diagnostic performance and prognostic utility of TMS-EEG in patients with DoC caused by severe brain injuries in the ICU.

Through this research, we aim to demonstrate that:

• TMS-EEG can detect 95% of conscious patients who are defined as conscious by a combination of tests that aim to detect overt and covert consciousness.
• TMS-EEG measurements can predict 6-month outcomes on the Disability Rating Scale (DRS) in patients in an acute vegetative state, controlling for age, Glasgow Coma Scale (GCS) score, and injury mechanism

All participants will undergo repeated behavioral assessments, task-based electroencephalography (EEG), and TMS-EEG. Of note, conventional brain magnetic resonance imaging (MRI) and task-based functional MRI are optional.

Inclusion Criteria:

1. Age greater than or equal to 18
2. Functionally independent at baseline
3. Acquired brain injury within the last 28 days
4. Disorder of consciousness, as defined by no instance of following commands (i.e., Glasgow Coma Scale motor score = 6) on two or more consecutive assessments
5. Continuous intravenous sedation able to be discontinued for at least 10 minutes
6. ICU clinicians approve safe placement of 64-electrode EEG cap on the scalp

Additional inclusion criteria are present in the study protocol.

Exclusion Criteria:

1. Status epilepticus or uncontrolled seizure disorder
2. No head CT scan from current hospital admission AND contraindications for MRI: conductive, ferromagnetic, or other magnetic-sensitive metals implanted in the head (e.g., cochlear implants, implanted electrodes/stimulators, aneurysm clips or coils, stents, bullet fragments)
3. Medical instability, restlessness, or other factors identified by the PI that would either prevent safe participation or compromise data acquisition
4. Hemicraniectomy

If a subject meets a contraindication for MR imaging, the subject may participate in all other aspects of the study except MRI.