Title Page

Contents

Abstract 9

INTRODUCTION 11

Materials and Methods 15

Clinical presentation 15

Surgical method 16

Evaluation of LSR 17

Electrode Position 17

Stimulation Parameters 18

Statistical analysis 20

Results 21

Basic demographic findings 21

Clinical outcome 22

Findings of LSR 23

Discussion 27

Limitation 32

Conclusion 33

Figure Legends 34

References 55

Appendix 59

논문요약 61

Table 1. Basic demographics of cases in the study 37

Table 2. The factors related to clinical outcome 40

Table 3. The factors related to the artifact 44

Figure 1. The density plot of optimal stimulation range 48

Figure 2. Relationship between stimulation intensity, abnormal muscle response,and onset latency 49

Figure 3. Abnormal muscle response seen at upper and lower branch facial muscles. 50

Figure 4. The density plot of onset latency for optimal range and 30mA stimulation 51

Figure 5. Comparison between the optimal range and high 30mA stimulation before and after decompression 52

Figure 6. Patterns of lateral spread response waveforms 53

Figure 7. Schematic representations of route of the lateral spread response and lateral spread artifact 54