Altered states of consciousness: processed EEG in mental disease

Area of Science:

• Neuroscience
• Gerontology
• Medical Diagnostics

Background:

• Rising life expectancy and an aging European population contribute to an increased incidence of mild cognitive impairment.
• Mild cognitive impairment can be a predictor for neurodegenerative diseases like Alzheimer's Disease and Vascular Dementia.
• Early diagnosis is crucial for managing cognitive decline and associated neurological conditions.

Purpose of the Study:

• To explore the utility of neurophysiological techniques for the early diagnosis of cognitive impairment.
• To investigate the potential of bispectral analysis and the Bispectral Index as diagnostic tools for mental diseases.

Main Methods:

• Utilized neurophysiological techniques to assess cognitive activity in normal subjects and patients.
• Analyzed power and phase relationships in different brainwave bands (alpha, beta, delta, theta) using bispectral analysis.
• Quantified brain signal characteristics to identify objective correlates of cognitive function.

Main Results:

• Cognitive impairment is associated with decreased alpha/beta band power and coherence, indicating cortical disconnection.
• Increased delta and theta band power and coherence suggest deafferentation from subcortical structures in cognitive impairment.
• Bispectral analysis revealed the Bispectral Index as a potentially useful and simple tool for early detection.

Conclusions:

• Neurophysiological methods offer simple, inexpensive, and objective means for early cognitive impairment diagnosis.
• Specific alterations in brainwave band power and coherence patterns are indicative of different types of cognitive dysfunction.
• The Bispectral Index, derived from bispectral analysis, shows potential for early diagnosis of mental diseases, including dementia.