scholarly journals USEFULNESS OF BRAIN SIGNALS FOR THE DETECTION OF LOSS OF CONSCIOUSNESS IN ANESTHESIA - Overview of the Problem and Results from a Clinical Study

2016 ◽  
Vol 13 (114) ◽  
pp. 20151027 ◽  
Author(s):  
Enzo Tagliazucchi ◽  
Dante R. Chialvo ◽  
Michael Siniatchkin ◽  
Enrico Amico ◽  
Jean-Francois Brichant ◽  
...  

Loss of cortical integration and changes in the dynamics of electrophysiological brain signals characterize the transition from wakefulness towards unconsciousness. In this study, we arrive at a basic model explaining these observations based on the theory of phase transitions in complex systems. We studied the link between spatial and temporal correlations of large-scale brain activity recorded with functional magnetic resonance imaging during wakefulness, propofol-induced sedation and loss of consciousness and during the subsequent recovery. We observed that during unconsciousness activity in frontothalamic regions exhibited a reduction of long-range temporal correlations and a departure of functional connectivity from anatomical constraints. A model of a system exhibiting a phase transition reproduced our findings, as well as the diminished sensitivity of the cortex to external perturbations during unconsciousness. This framework unifies different observations about brain activity during unconsciousness and predicts that the principles we identified are universal and independent from its causes.


1981 ◽  
Vol 12 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Donald L. McCanna ◽  
Giacinto DeLapa

This report reviews 27 cases of children exhibiting functional hearing loss. The study reveals that most students were in the upper elementary grades and were predominantly females. These subjects were functioning below their ability level in school and were usually in conflict with school, home, or peers. Tests used were selected on the basis of their helping to provide early identification. The subjects' oral and behavioral responses are presented, as well as ways of resolving the hearing problem. Some helpful counseling techniques are also presented.


2014 ◽  
Vol 19 (5) ◽  
pp. 3-12
Author(s):  
Lorne Direnfeld ◽  
David B. Torrey ◽  
Jim Black ◽  
LuAnn Haley ◽  
Christopher R. Brigham

Abstract When an individual falls due to a nonwork-related episode of dizziness, hits their head and sustains injury, do workers’ compensation laws consider such injuries to be compensable? Bearing in mind that each state makes its own laws, the answer depends on what caused the loss of consciousness, and the second asks specifically what happened in the fall that caused the injury? The first question speaks to medical causation, which applies scientific analysis to determine the cause of the problem. The second question addresses legal causation: Under what factual circumstances are injuries of this type potentially covered under the law? Much nuance attends this analysis. The authors discuss idiopathic falls, which in this context means “unique to the individual” as opposed to “of unknown cause,” which is the familiar medical terminology. The article presents three detailed case studies that describe falls that had their genesis in episodes of loss of consciousness, followed by analyses by lawyer or judge authors who address the issue of compensability, including three scenarios from Arizona, California, and Pennsylvania. A medical (scientific) analysis must be thorough and must determine the facts regarding the fall and what occurred: Was the fall due to a fit (eg, a seizure with loss of consciousness attributable to anormal brain electrical activity) or a faint (eg, loss of consciousness attributable to a decrease in blood flow to the brain? The evaluator should be able to fully explain the basis for the conclusions, including references to current science.


1951 ◽  
Vol 17 (1) ◽  
pp. 35-38 ◽  
Author(s):  
Frank C. Bone ◽  
Chester Cassel ◽  
Julian M. Ruffin ◽  
Robert J. Reeves

1961 ◽  
Vol 40 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Charles H. Brown ◽  
Mauro Merlo ◽  
John B. Hazard

2007 ◽  
Vol 177 (4S) ◽  
pp. 197-197 ◽  
Author(s):  
Hazem O. Orabi ◽  
Tamer A. Aboushwareb ◽  
Yuan Yuan Zhang ◽  
James J. Yoo ◽  
Anthony Atala

2005 ◽  
Vol 29 (3) ◽  
pp. 291-302 ◽  
Author(s):  
P. Sewell ◽  
J. Vinney ◽  
S. Noroozi ◽  
R. Amali ◽  
S. Andrews

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