Spinal epidural abscess secondary to gram-negative bacteria: case report and literature review

Abstract

Bacterial spinal epidural abscess (SEA) is a rare suppurative infection that commonly presents with nonspecific symptoms along with the infrequent triad of fever, back pain, and neurological deficits. Risk factors include diabetes mellitus, intravenous drug use, degenerative disc disease, infection with human immunodeficiency virus, and recent trauma or surgery. Patients with SEA often experience poor outcomes such as permanent neurological deficits, residual motor weakness, and even death. Staphylococcus aureus is the most predominant organism known to cause SEA; however, gram-negative bacteria are isolated in a small percentage of cases. Here we report three cases of SEA caused by gram-negative organisms. Each patient had identifiable risk factors known to increase the risk for SEA, and upon presentation had symptoms of SEA. Upon work up, the patients had positive cultures for gram-negative organisms and MRI imaging confirmed the presence of SEA. One patient made a full recovery while the other two cases resulted in permanent paraplegia. These cases stress the importance of considering SEA even in the presence of gram-negative infections, despite them being a rare cause. Furthermore, these cases emphasize the importance of broad-spectrum antibiotics that cover gram-negative bacteria in patients found to have risk factors along with symptoms of SEA.

Keywords: Diseases of the nervous system; Gram-negative infection; Spinal epidural abscess.

Figure 1.

T2 weighted sagittal MRI of the spine with gadolinium demonstrating a 4.0 × 0.3 x 1.7 cm anterior epidural fluid collection with peripheral enhancement compatible with epidural abscess spanning C5-C7. There is early suspected discitis and osteomyelitis at the C5-C6 level. The epidural collection compresses the cervical spinal cord resulting in cord edema at the affected levels.

Figure 2.

T2 weighted sagittal MRI of the spine with gadolinium demonstrating 0.55 cm ventral epidural abscess at the level of L2-L3 with discitis osteomyelitis at L2-L3 and loss of height at the L2 and L3 vertebral bodies. Additionally, there is osteomyelitis of the posterior aspect of the L4 vertebral body.