Objective: To study the changes in somatosensory evoked potentials (SEPs) and brainstem auditory evoked potentials (BAEPs) during intracranial hypertension.
Method: A rabbit model of acute intracranial hypertension was developed. Thirty New Zealand rabbits were divided into 3 group. Both Group A and B were groups with intracranial hypertension; Group C was the control group. In Group A, balloons were placed to the right parietal lobe beneath the dura mater; in Group B, to temporal at the middle fossa near the brainstem.
Result: (1) In Group A, when ICP rose to (1.48 +/- 0.35) kPa, P1 amplitude of SEPs was significantly changed, whereas latencies of Wave IV, V, and VII of BAEPs were prolonged when ICP rose to (9.40 +/- 1.60) kPa. In group B, P1 amplitude of SEPs was changed when ICP reached (8.10 +/- 1.25) kPa, and latency of Wave III of BAEPs was prolonged when ICP rose to (3.11 +/- 0.80) kPa. (2) P1 amplitude increased with ICP value when the balloon volume increased from V = 0.0 ml, ICP = (0.43 +/- 0.10) kPa to V = 0.4 ml, ICP = (2.44 +/- 0.65) kPa and then decreased afterward.
Conclusions: (1) Changes in SEPs and BAEPs relate to not only ICP value but also the location of the balloon. (2) With the increasing of ICP, P1 amplitude increases firstly and then decreases.