Exploratory investigation into mild brain injury and discriminant analysiswith high frequency bands (32-64 Hz)

QEEG variables (five activation, two relationship variables, 19 locations a nd five bands up to 64 Hertz) were collected under eyes dosed condition (un der both 32 and 64 Hertz conditions) on 91 subjects, consisting of 32 mild brain-injured subjects (no loss of consciousness greater than 20 minutes) a nd 52 normals over the age of 14. An additional seven subjects who were unc onscious seater than 20 minutes were available for analysis. Previous discr iminant function analysis developed by Thatcher et at. was employed on the eyes closed 32 Hertz condition to ascertain its robustness for time periods greater than 1 year and for significant periods of unconsciousness. A sepa rate discriminant for subjects was developed, employing only frontal high f requency coherence figures. The Thatcher discriminant could reliably (79%) identify all subjects up to 43 years post accident. The high frequency disc riminant effectively identified 87% of the brain injured across an time per iods (without significant loss of consciousness) and 100% of subjects withi n 1 year of accident. The combination of the discriminants resulted in a 10 0% accuracy rate for the 39 brain injured subjects for which discriminate v alues were available.