Neurological Outcomes Following Surgical Resection of Intradural Extramedullary Spinal Tumors: A Retrospective Analysis Using the American Spinal Injury Association (ASIA) Impairment Scale

Objective Intradural extramedullary (IDEM) tumors, predominantly meningiomas and schwannomas, frequently require surgical resection. However, reliable predictors of postoperative neurological outcomes remain poorly defined. This study aimed to identify risk factors for neurological deterioration following IDEM tumor resection and to evaluate outcomes using the American Spinal Injury Association (ASIA) Impairment Scale. Methods A retrospective chart review was conducted of 93 consecutive patients who underwent surgical resection of IDEM tumors (52 meningiomas, 41 schwannomas) at a single tertiary neurosurgical center between 2008 and 2019. Patient demographics, tumor characteristics, perioperative variables, and medical comorbidities were systematically analyzed. The primary outcome was change in ASIA score from admission to last follow-up. Statistical analyses included paired t-tests, chi-square tests, Spearman correlations, and multivariable comparisons to identify potential risk factors. Results The cohort comprised 38 males and 55 females with a mean age of 59.8 ± 13.2 years. Mean operative duration was 142.2 ± 50.1 minutes. Median follow-up was 5 months. Mean ASIA score improved significantly from 4.14 ± 0.84 at admission to 4.74 ± 0.66 at follow-up (p < 0.001). Individual outcomes showed improvement in 49 patients (52.7%), stability in 43 (46.2%), and deterioration in 1 (1.1%). Notably, patients with obesity (p = 0.005) and a smoking history (p = 0.043) demonstrated significantly lower baseline ASIA scores but achieved comparable postoperative outcomes. No significant associations were identified between neurological outcomes and age, sex, tumor pathology, tumor location, symptom duration, operative duration, tumor size, or the presence of medical comorbidities. Conclusions Surgical resection of IDEM tumors demonstrates excellent neurological safety, with significant functional improvement in the majority of patients. The ASIA scale effectively captures neurological outcomes in this population. No modifiable perioperative risk factors for neurological deterioration were identified, supporting the safety of surgery across diverse patient populations.