Over-complete discrete wavelet transformation of the normal auditory brainstem response improves prediction of outcome following severe acute closed head injury.

Previous research has shown that complex statistical analysis ( discriminant function analysis) of a 'normal' auditory brainstem response ( ABR) result can improve this measure's ability to predict subject outcome following severe acute closed head injury ( ACHI). We hypothesized that adding the ABR's time-frequency information to such an analysis would improve this predictive value even further. 'Normal' ABR results were sampled from 69 severe ACHI subjects ( 22 of whom died and 47 of whom lived) and their time-frequency information extracted using an over-complete discrete wavelet transformation ( OCDWT). A series of logistic regression analyses then showed correct predictions of death and survival as follows: ABR measures only 72 and 89% ( respectively), ABR OCDWT measures only 82 and 89% ( respectively), and ABR and ABR OCDWT measures combined 86 and 93% ( respectively). These results showed that the addition of time-frequency information can improve the ability of the 'normal' ABR result to predict outcome following severe ACHI. Copyright (C) 2006 S. Karger AG, Basel.