Asset Details
Do you wish to reserve the book?
Breakdown in cortical effective connectivity during midazolam-induced loss of consciousness
Hey, we have placed the reservation for you!
By the way, why not check out events that you can attend while you pick your title.
Oops! Something went wrong.
Looks like we were not able to place the reservation. Kindly try again later.
Are you sure you want to remove the book from the shelf?
Breakdown in cortical effective connectivity during midazolam-induced loss of consciousness
Do you wish to request the book?
Breakdown in cortical effective connectivity during midazolam-induced loss of consciousness
Please be aware that the book you have requested cannot be checked out. If you would like to checkout this book, you can reserve another copy
We have requested the book for you!
Your request is successful and it will be processed during the Library working hours. Please check the status of your request in My Requests.
Oops! Something went wrong.
Looks like we were not able to place your request. Kindly try again later.
Journal Article
Breakdown in cortical effective connectivity during midazolam-induced loss of consciousness
2010
Overview
By employing transcranial magnetic stimulation (TMS) in combination with high-density electroencephalography (EEG), we recently reported that cortical effective connectivity is disrupted during early non-rapid eye movement (NREM) sleep. This is a time when subjects, if awakened, may report little or no conscious content. We hypothesized that a similar breakdown of cortical effective connectivity may underlie loss of consciousness (LOC) induced by pharmacologic agents. Here, we tested this hypothesis by comparing EEG responses to TMS during wakefulness and LOC induced by the benzodiazepine midazolam. Unlike spontaneous sleep states, a subject's level of vigilance can be monitored repeatedly during pharmacological LOC. We found that, unlike during wakefulness, wherein TMS triggered responses in multiple cortical areas lasting for >300 ms, during midazolam-induced LOC, TMS-evoked activity was local and of shorter duration. Furthermore, a measure of the propagation of evoked cortical currents (significant current scattering, SCS) could reliably discriminate between consciousness and LOC. These results resemble those observed in early NREM sleep and suggest that a breakdown of cortical effective connectivity may be a common feature of conditions characterized by LOC. Moreover, these results suggest that it might be possible to use TMS-EEG to assess consciousness during anesthesia and in pathological conditions, such as coma, vegetative state, and minimally conscious state.
Publisher
National Academy of Sciences,National Acad Sciences
Subject
/ Anesthetics, Intravenous - administration & dosage
/ Brain
/ Cerebral Cortex - anatomy & histology
/ Cerebral Cortex - physiology
/ Coma
/ Evoked Potentials, Motor - physiology
/ eyes
/ Humans
/ Male
/ Midazolam - administration & dosage
/ Sleep
/ Transcranial Magnetic Stimulation
/ Unconsciousness - chemically induced
