LAUSR

STUDY DESIGN Retrospective review. OBJECTIVES Spinal intradural extramedullary abscess (SIEA) is a rare disease with an unknown incidence. In this study, we systematically described the clinical course of SIEA in a large cohort with acute onset of neurological illness, assessed the morbidity and mortality rates, and determined the potential risk factors for mortality. METHODS Electronic medical records of patients diagnosed with SIEA at a single institution for the period between September 2005 and December 2020 were retrieved. RESULTS Over a period of 15 years, 881 patients with spinal infections were treated either conservatively or surgically at our center, of whom 45 patients (45/881, 5.1%) had SIEA. The overall mean age was 69.6 ± 5.6 years of patients diagnosed with SIEA and all of them underwent posterior decompression via laminectomy. The mean Charlson Comorbidity Index (CCI) was 6.9 ± 2.5, indicating a poor baseline reserve. Progressive neurological decline was observed in all patients (mean motor score, 88.6 ± 9.7). The in-hospital rate and 90-day mortality were 4.4% and 10%, respectively. Mortality was not surgery related. Most importantly, the patients' motor deficits and blood infection parameters significantly improved after surgery. Risk factors for mortality were increased age, comorbidities as measured by CCI, and preoperative motor weakness (MS). CONCLUSIONS Immediate surgical decompression via laminectomy, with antiseptic irrigation and drainage of the subdural space, followed by antibiotic therapy, appears to be the key to ensuring beneficial clinical outcomes to treatment of rare diseases such as SIEA.