Diagnostic Potential of Distortion Product Otoacoustic Emissions in Noninvasive Assessment of Elevated Intracranial Pressure: Different Patterns of DPOAE Alterations in the Guinea Pig

Table 1

Overview of all measured ICP intervals with stable ICP in the range of ±2 mmHg of the target value indicated in the table and the information whether they were valid. For valid ICP intervals the pattern of DPOAE level alterations is given. For explanation of the two patterns see Figure 1. Note that the second pattern only occurred at the respective highest ICP value.

Animal no.	ICP [mmHg]	Valid	Pattern
1	18	yes	first
	22	yes	first
	24	yes	second
2	18	no^1
	22	yes	first
	24	yes	first
3	18	yes	no change
	22	yes	first
	24	yes	second
4	18	yes	first
	22	no^2
5	18	yes	first
	22	yes	first
	24	yes	second
6	18	yes	no change
	22	no^2
7	18	no^1
	22	no^1	first
	24	yes
8	18	no^1
	22	yes	no change
	24	no^1
9	18	yes	first
	22	yes	second
	24	no^2
10	18	yes	first
	22	yes	first
	24	yes	second

¹invalid because mean_postICP did not stabilize in the range of ±2 SD_baseline compared to mean_preICP in all frequencies.
²invalid because SaO₂ dropped below 80%. In these cases, no further pressure steps were recorded.
See Section 2.3 for calculations and inclusion criteria.