Predicting residual neurologic deficits using the Spinal Infection Treatment Evaluation score after surgery for thoracic and lumbar spinal epidural abscess: a retrospective study in Taiwan.

Study design: Retrospective, consecutive case series.

Purpose: We assessed the predictive validity of the Spinal Infection Treatment Evaluation (SITE) score to determine the likelihood of residual neurological deficits (ND) following surgical treatment of spinal epidural abscess (SEA).

Overview of literature: SEA is a severe spinal infection that can result in irreversible ND and sepsis if left untreated. Although various risk factors have been proposed to predict postoperative neurological outcomes, the optimal predictors remain unclear.

Methods: A total of 45 patients diagnosed with de novo thoracic or lumbar SEA who underwent posterior-only surgical decompression between 2005 and 2014, with a minimum postoperative follow-up of 2 years, were included. Patients were stratified based on the presence or absence of postoperative residual ND, and neurological function was assessed immediately after surgery and at the final followup using the Frankel grading system. SITE scores, along with clinical and radiological data associated with residual ND, were collected. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to identify significant predictors.

Results: Patients with residual ND had significantly lower SITE scores than those without residual ND (4.3±1.3 vs. 7±1.8, p<0.0001). Multivariate analysis identified the SITE score as an independent predictor (odds ratio, 2.70; p=0.012). ROC analysis showed that a SITE score ≤6 predicted residual ND with 73.3% sensitivity and 100% specificity, with an area under the curve of 0.877 (p<0.001). Other significant predictors included cauda equina syndrome and a shorter symptom-to-surgery interval, both of which were associated with a higher risk of residual ND.

Conclusions: The SITE score is a reliable and independent predictor of residual ND after surgery for SEA. SITE scores <6 indicate a significantly higher risk of postoperative ND.