TABLE 4.
Correlation of MEP Findings and Postoperative Muscle Strength of the 208 Muscles in the 59 Operations for Intramedullary Tumors/Lesions.
| Muscle strength | |||
|---|---|---|---|
| MEP findings | Worse | Unchanged/improved | Sum |
| No response | 10 | 48 | 58 |
| Negative MEP findings: | |||
| Stable | 6 | 78 | 84 |
| Appeared after initial absence | 0 | 11 | 11 |
| Slight change | 0 | 3 | 3 |
| Temporarily disappeared or declined to < 20% baseline amplitude with recovery at the end | 2 | 13 | 15 |
| Subtotal: negative MEP | 8 | 105 | 113 |
| Positive MEP warnings: | |||
| Declined to <20% baseline amplitude | 5 | 9 | 14 |
| Disappeared | 10 | 13 | 23 |
| Subtotal: positive MEP | 15 | 22 | 37 |
Positive Predictive Value was 0.41 (=15/37) and Negative Predictive Value was 0.93 (=105/113)