Clinical Features and Diagnosis of Intramedullary Spinal Cord Abscess in Adults: A Systematic Review

Background and objectives: Intramedullary spinal cord abscess (ISCA) was described 200 years ago but remains poorly understood and is often mistaken for immune-mediated or neoplastic processes. We present a systematic review of ISCA in adults, describing the clinical presentation, diagnostic features, treatment strategies, and outcomes.

Methods: Database searches for intramedullary abscess were performed on April 15, 2019, and repeated on February 9, 2022, using PubMed and EMBASE with 2 unpublished cases also included. Publications were independently reviewed for inclusion by 2 authors followed by adjudication. Data were abstracted using an online form and then analyzed for predictors of disability.

Results: A total of 202 cases were included (median age 45 years [interquartile range 31-58]; 70% male). Thirty-one percent of those affected had no identified predisposing condition. The most common symptom was weakness (97%), and the median symptom duration before presentation was 10 days (interquartile range 5-42). An MRI showed restricted diffusion in 100% of 8 cases where performed and enhancement in 99% of 153 cases where performed. The most common organisms were Mycobacterium tuberculosis (29%), Streptococcus sp. (13%), and Staphylococcus sp. (10%). All patients received antimicrobial therapy; surgical drainage was performed in 65%. At follow-up (median 6 months), 12% had died, 69% were ambulatory, and 77% had improved compared with clinical nadir. Of those who underwent operative intervention, surgery within 24 hours of diagnosis was associated with an increased likelihood of being ambulatory at follow-up compared with surgery after 24 hours (odds ratio 4.44; 95% CI 1.26-15.61; p = 0.020).

Discussion: ISCA is important to consider in any patient presenting with acute-to-subacute, progressive myelopathy. Immunocompromise and typical signs of infection (e.g., fever) are often absent. Diffusion restriction and gadolinium enhancement on MRI seem to be sensitive. Antimicrobial therapy with surgical drainage is the most common therapeutic approach, but morbidity remains substantial. If performed, urgent surgery may be more beneficial.