Long-term outcome prediction after a traumatic brain injury using early somatosensory and acoustic evoked potentials: analysis of the predictive value of the different single components of the potentials.

PURPOSE

The prediction of the long-term outcome of comatose patients after severe traumatic brain injury (TBI) using early somatosensory and acoustic evoked potentials is controversial. It was our aim to examine the different single components of the evoked potentials regarding their predictive capacity in comatose patients.

METHODS

We examined the amplitude and latency of the wave N20, the amplitude differences between right and left hemisphere, the central conduction time (CCT), the amplitude ratio N20 left/N20 right, the amplitude and latency of peak V, the inter-peak latency I-V and the amplitude ratio V/I. The long-term clinical outcome of the patients was re-evaluated 3 years after their discharge and correlated with the different components.

RESULTS

Only the central conduction time (CCT) and the latency of the wave N20 indicated a statistical correlation with the later outcome (p = 0.0366). The amplitude ratio of wave V/I of the EAEP did not reveal a significant statistical difference between the various outcome groups.

CONCLUSIONS

In this study, the use of single components of the SSEP and EAEP per se could not predict the long-term clinical outcome after TBI. Combined systems such as the Riffel Score are necessary in order to achieve this goal.