My main project is a clinical trial focused on Disorders of Consciousness (DoC). Patients who suffer from DoC are in one of several states: Comatose, Unresponsive Wakefulness Syndrome (UWS, formerly referred to as “Vegetative State”), or Minimally Conscious States (MCS+/-). One of the clinical motivations for this project is that as many as 40% of DoC patients are misdiagnosed. The clinical goals of this project are: to improve diagnostic, prognostic and therapeutic techniques. The main scientific goal is to deepen our understanding of human consciousness, especially Levels of Consciousness (LoC).

In stage one, the clinical trial has comprised these components: behavioral assessments using the Coma Recovery Scale-Revised; fMRI scanning for anatomy, magnetic resonance spectroscopy (MRS) for GABAergic activity in the Posterior Cingulate Cortex, arterial spin labeling for cerebral blood flow, and the resting state; FDG-PET for brain metabolism; and double-blind administration of zolpidem/placebo. For this stage our patient number already exceeds 80.

In January 2023, we are beginning stage two, for which most BCRC/GIMBC PIs are actively involved. The clinical trial described above will continue, but we are now adding new measures. These include EEG (P300, Readiness Potential, etc.), Heart-Evoked Response (HER), several physiological-behavioral assessments for circadian rhythms, and olfactory response. Expectations for stage two include: identification of less resource-expensive means for detecting consciousness; development of methods for continuous monitoring of LoC outside of the clinical environment; and, increased understanding of brain-body interactions (heart-brain, circadian rhythms, etc.) effects on consciousness fluctuations. Finally, because some among our patients suffer from Locked-in Syndrome (LiS), we are exploring methods whereby we can enhance their ability to communicate.

The figure below (Thibaut et al. 2019) summarizes the scope of our investigations as well as standard cognitive and motor functions used for patient assessment:

Thibaut A, et al. Therapeutic interventions in patients with prolonged disorders of consciousness. Lancet Neurol. 2019 18, 6, 600-614.