CASE REPORT SPINE Volume 38, Number 13, pp E844–E847 ©2013, Lippincott Williams & Wilkins E844 www.spinejournal.com June 2013 Thoracolumbosacral Spinal Subdural Abscess Magnetic Resonance Imaging Appearance and Limited Surgical Management Jad G. Khalil, MD, Ahmad Nassr, MD, Felix E. Diehn, MD , Norbert G. Campeau, MD , John L. Atkinson, MD, Irene G. Sia, MD , and Amgad Hanna, MD Study Design. Case report and review of relevant literature. Objective. To report a rare case of a thoracolumbosacral spinal subdural abscess (SSA) and highlight the magnetic resonance imaging (MRI) appearance and surgical management. Summary of Background Data. SSA is rare, as most intraspinal abscesses are epidural in location. Extensive thoracolumbosacral SSA has only rarely been reported. The MRI features and options for limited surgical management are not well described. Methods. A case report of SSA is presented and relevant literature is reviewed. Results. An elderly female presented with worsening back pain and sepsis. MRI demonstrated an extensive intraspinal abscess, extending from the upper thoracic spine to the sacrum. Both axial and sagittal images demonstrated a subdural location of the collection, with preservation of the dorsal epidural fat and mass effect on the spinal cord. Cord compression was most marked at the T8 level. Limited midthoracic laminectomies were performed. The epidural space seemed normal intraoperatively. A limited longitudinal durotomy yielded purulent fluid. After intraoperative irrigation, primary dural repair was performed. At 2-year follow-up, the patient had no clinical, radiographical, or laboratory evidence of residual or recurrent spinal infection. Conclusion. Careful review of MRI can localize an intraspinal abscess to the subdural space. Even for extensive subdural collections, limited operative management can achieve excellent clinical outcome. Key words: spinal infection, spinal subdural abscess, spinal epidural abscess, neurological compromise, spinal cord compression, magnetic resonance imaging, limited laminectomy, antibiotic treatment. Level of Evidence: N/A Spine 2013;38:E844–E847 P rompt recognition and appropriate treatment of intra- spinal infections are paramount in obtaining a favor- able outcome. 1 –5 Although most spinal abscesses involve the epidural space, a rare and underdescribed entity is the subdural abscess. 2 Failure to recognize a spinal sub- dural abscess (SSA) can lead to suboptimal treatment and patient outcome. 1 CASE REPORT An 82-year-old female presented with an acute exacerbation of chronic back pain and sepsis, followed by increasing diffi- culty in ambulating and urinary retention. Her physical exam- ination was notable for bilateral symmetrical lower extremity weakness, hyperreflexia, with neck stiffness, and pain with range of motion characteristic of meningeal irritation. A magnetic resonance imaging (MRI) examination of the entire spine (Figure 1) showed a peripherally enhancing T2 hyperin- tense process extending from T2 to the sacrum worrisome for abscess, with associated cord compression at the midthoracic region. Although this was initially favored to be an epidural collection, careful review of the MRI demonstrated preserva- tion of the epidural space, compatible with a subdural abscess. Because her multiple comorbidities and precarious clinical sta- tus, a limited approach was chosen for decompression. Mid- thoracic laminectomies (partial T6, complete T7, and partial T8) were performed, revealing a normal epidural space. A limited longitudinal durotomy was then performed and 30 mL of purulent fluid was expressed (Figure 2). Intraoperative irrigation, by passing a rubber catheter cephalad and caudad, was continued until the return was clear. The dural sac was repaired primarily. She was placed on intravenous antibiot- ics and cultures grew methicillin-susceptible Staphylococcus aureus, which was consistent with the results of her preopera- tive blood cultures. Nafcillin was chosen because of its better cerebrospinal fluid penetration. After 8 weeks of intravenous antibiotics, the patient was placed on oral antibiotic suppres- sion with cephalexin. Postoperative magnetic resonance images at 15 months (Figure 3) revealed no residual collection. Her weakness grad- ually improved and her inflammatory markers normalized after an 8-week course of antibiotics. At 2-year follow-up, she had intact lower extremity strength and no clinical, radio- graphical, or laboratory evidence of residual or recurrent infection. From the Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN. Acknowledgment date: January 15, 2013. Acceptance date: February 14, 2013. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. No relevant financial activities outside the submitted work. Address correspondence and reprint requests to Ahmad Nassr, MD, Department of Orthopedic Surgery, Mayo Clinic, 200 First St., SW, Rochester MN 55905; E-mail: Nassr.ahmad@mayo.edu DOI: 10.1097/BRS.0b013e31828d5f30 Copyright © 2013 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.