Consciousness, Level Altered Clinical Trial
Official title:
The Neural Mechanisms of Anesthesia and Human Consciousness (LOC-2013)
The explanation of consciousness poses one of the greatest challenges to science and
philosophy in the 21st century. It remains unclear what consciousness is and how it emerges
from brain activity. By studying anesthesia and sleep, the investigators aim to reveal what
happens in the brain when consciousness is lost and when it returns. During the study, a
series of Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI) and
electroencephalography (EEG) studies will be carried out on healthy male subjects to reveal
the neural correlates of consciousness. Consciousness of the subjects will be manipulated
with normal sleep and anesthetic agents dexmedetomidine and propofol.
First, various neurophysiological tools to separate consciousness, connectedness and
responsiveness during normal sleep will be tested. The most suitable methods and subjects
will be selected and then tested during anesthetic-induced sedation and loss of
responsiveness (LOR). The anesthetics (dexmedetomidine or propofol) will be administered as
target-controlled infusions (TCI) with step-wise concentration-increments until LOR is
detected. Then, TCIs are repeated in the same subjects but adjusted according to the
individual drug target concentrations sufficient for LOR, and a series of PET perfusion
imaging measurements will be performed to obtain the brain activity information in various
states of consciousness. The same subjects will then be imaged with PET for brain activity
after sleep deprivation (awake), during various sleep stages and immediately after
awakening. Finally, ten dexmedetomidine subjects will be given the drug once more, and
functional MRI (fMRI) data will be collected at various states of consciousness before and
during verbal and nonverbal vocalizations. EEG will be continuously collected in all
sessions. The depth of anesthesia will be measured using quantitative EEG and bispectral
index (BIS) monitoring.
The results may lead to the discovery of new and better objective indicators of the depth of
anesthesia and consciousness, and new insights into the understanding of neural mechanisms
behind drug-induced loss of consciousness and ultimately the mechanisms of action of
(general) anesthetics as well as consciousness itself.
(not needed) ;
Allocation: Randomized, Endpoint Classification: Pharmacodynamics Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Basic Science
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Completed |
NCT03328221 -
Physical Activity on Heart Rate Variability in Patients With Severe Acquired Brain Injury
|
||
| Completed |
NCT04653597 -
Non-invasive Airway Management of Comatose Poisoned Emergency Patients
|
Phase 3 | |
| Completed |
NCT04366544 -
Effects of an 8-day Advanced Meditation, Samyama on Physical, Psychological and Spiritual Wellbeing ,and Associated Neural Mechanisms
|
N/A | |
| Completed |
NCT06029205 -
Mindfulness Training in Nurses and Its Effect on Work Stress
|
N/A | |
| Completed |
NCT03814356 -
Stimulant Therapy Targeted to Individualized Connectivity Maps to Promote ReACTivation of Consciousness
|
Phase 1 | |
| Not yet recruiting |
NCT06003127 -
REcovery From DEXmedetomidine-induced Unconsciousness
|
N/A |