To present a systematic review of the clinical presentation, diagnostic features, and outcomes of adult intramedullary spinal cord abscesses (ISCA).

Though ISCA was first described 200 years ago, it remains poorly understood. ISCA causes significant morbidity and may be mistaken for immune-mediated or neoplastic processes. ISCA is more common in children and is usually associated with spinal dysraphism (e.g. dermal sinus). This association is not seen in adult ISCA, suggesting a different pathogenesis. There are no formal diagnostic criteria or standard of care for ISCA. We present the first systematic review of ISCA in adults including 121 cases.

PubMed and EMBASE were searched for “(spinal cord abscess) NOT epidural.” Cases were independently reviewed by two authors. Data were analyzed using Excel and STATA.

121 cases were included (median age 50; 71% male). 12% of reported patients were immunosuppressed/immunocompromised. Causative organisms included bacteria (79%), tuberculosis (13%), fungi (5%), and parasites (3%). The most common bacteria were Streptococcus (20%) and Staphylococcus (14%) species. The median symptom duration prior to presentation was 7 days. The most common symptoms were weakness (97%), sensory changes (81%), pain (65%), and bowel/bladder dysfunction (60%). Fever was present in only 43%. MRI showed restricted diffusion in 100% (of 7 cases where performed) and enhancement in 99% (of 91 cases where performed; ring enhancement in 86%). All patients received antimicrobial therapy; surgical drainage was performed in 64%. At the time of last follow up 14% had died, 24% had no clinical improvement, and 34% remained non-ambulatory.

ISCA affects predominantly immunocompetent adults, with a variety of causative organisms. The presentation is often acute-to-subacute myelopathy; fever is not a reliable sign. Diffusion restriction and gadolinium enhancement on MRI are very sensitive signs. Antimicrobial therapy with surgical drainage is the most common therapeutic approach, but morbidity remains significant.