Patients who have postoperative neurological deficit following lumbar spine surgery are 22 times more likely to have exhibited intraoperative somatosensory-evoked potential (SSEP) changes. This is according to a new meta-analysis published recently in the journal Spine by Robert Chang (University of Pittsburgh Medical Centre, Pittsburgh, USA) et al.
The aim of the study was to determine the diagnostic accuracy of intraoperative lower extremity SSEP changes for predicting postoperative neurological deficit. As a secondary analysis, three subtypes of intraoperative SSEP changes—reversible, irreversible, and total signal loss—were also evaluated.
The meta-analysis included prospective and retrospective studies identified in PubMed, Web of Science, and Embase, with outcomes of patients who received intraoperative SSEP monitoring during lumbar spine surgery. A total of 5,607 patients were included in the study, which calculated sensitivity, specificity, and diagnostic odds ratio (DOR).
All significant intraoperative SSEP changes were found to have a sensitivity of 44% and specificity of 97% with a DOR of 22.13 (95% confidence interval [CI], 11.30–43.34). Reversible and irreversible SSEP changes had sensitivities of 28% and 33% respectively and both had specificities of 97%.
The DORs for reversible and irreversible SSEP changes were 13.93 (95% CI, 4.60–40.44) and 57.84 (95% CI, 15.95–209.84), respectively. Total loss of SSEPs had a sensitivity of 9% and specificity of 99% with a DOR of 23.91 (95% CI, 7.18–79.65).
These results indicate that SSEP changes during lumbar spine surgery are “highly specific but moderately sensitive for new postoperative neurological deficits” say the researchers.