Electrophysiological assessments of cognition and sensory processing in TBI: Applications for diagnosis, prognosis and rehabilitation

This article from the International Journal of Psychophysiology shows the full acceptance of the use of EP and ERP testing to evaluate TBI. The paper is co-authored from the Defence Veterans Brain Injury Center (DVBIC), and this paper shows none of the quibbling or caveats about a lack of specificity or sensitivity in TBI. It is a paper that looks at full adoption for use, not a call for plenty of more studies and funding!

This ERP technology is ready for prime time in TBI. The peer review and publication process is how science moves forward, and the use of ERP for TBI evaluations is now accepted by the peer review process, but not the EEG/qEEG yet fully, and definitely not EEG based discriminants for TBI, which are now counseled against in the peer reviewed literature.

Jay

ABSTRACT

Traumatic brain injuries are often associated with damage to sensory and cognitive processing pathways. Because evoked potentials (EPs) and event-related potentials (ERPs) are generated by neuronal activity, they are useful for assessing the integrity of neural processing capabilities in patients with traumatic brain injury (TBI). This review of somatosensory, auditory and visual ERPs in assessments of TBI patients is provided with the hope that it will be of interest to clinicians and researchers who conduct or interpret electrophysiological evaluations of this population. Because this article reviews ERP studies conducted in three different sensory modalities, involving patients with a wide range of TBI severity ratings and circumstances, it is dif!cult to provide a coherent summary of !ndings. However, some general trends emerge that give rise to the following observations and recommendations:

1) bilateral absence of somatosensory evoked potentials (SEPs) is often associated with poor clinical prognosis and outcome;

2) the presence of normal ERPs does not guarantee favorable outcome;

3) ERPs evoked by a variety of sensory stimuli should be used to evaluate TBI patients, especially those with severe injuries;

4) time since onset of injury should be taken into account when conducting ERP evaluations of TBI patients or interpreting results;

5) because sensory de!cits (e.g., vision impairment or hearing loss) affect ERP results, tests of peripheral sensory integrity should be conducted in conjunction with ERP recordings; and

6) patients’ state of consciousness, physical and cognitive abilities to respond and follow directions should be considered when conducting or interpreting ERP evaluations.

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Consciousness: An Emergent Property Of Mind-Brain Interaction

Consciousness: An Emergent Property Of Mind-Brain Interaction – presented by Jay Gunkelman

A model of consciousness will be illustrated with physiological data from EEG and Event related potentials. Using millisecond level time resolution, a working model of the interaction between the mind and the brain will be constructed.

The Slow Cortical Potentials generated by Glial activity and the faster gamma activity reflecting activity of bound neural networks will be used to illustrate this model. The physiological correlates of concepts like intention, attention, memory, perception, awareness, sensory differentiation and conscious awareness will all be discussed within the framework of this model. Advanced concepts like neural network binding, nested rhythms, cross-spectral correlation, and the bispectrum will be discussed.

The DC potentials cause an instantaneous phase resetting and binding of a neural network, which can initiate synchronous activity within these neural networks. Current work using this model in clinical work on severe disorders of consciousness, including work by the International Brain Research Foundation on recovery of consciousness in coma cases will be reviewed. The simplest expression of the model: when the DC potentials reflecting activity of the mind interact with gamma activity reflecting neural activity in the brain, the emergent property of this interaction is consciousness.

[youtube]http://www.youtube.com/watch?v=Pv-msnzTk7o[/youtube]

From The Society for Scientific Exploration (SSE)