J Electrodiagn Neuromuscul Dis.  2021 Apr;23(1):11-14. 10.18214/jend.2020.00101.

Cauda Equina Syndrome Caused by a Sacral Insufficiency Fracture in the Lower Part of Zones 2 and 3: A Case Report

• Cha JM
• Kwon N
• Lee SJ
• Lee JW

• KMID: 2526167
• DOI: http://doi.org/10.18214/jend.2020.00101

Abstract

Sacral insufficiency fractures (SIFs) often cause referred low back pain, and are rarely accompanied by cauda equina syndrome (CES). We report a case of CES caused by SIF in the lower part of zones 2 and 3, which is not a typical location. A postmenopausal woman often sat on a chair for long periods, and pain in the coccyx and perianal area occurred. After 4 years, during which time the pain worsened and she developed urinary and fecal incontinence, magnetic resonance imaging showed a SIF involving the S3-S5 vertebrae. Prolonged latency of the bulbocavernosus reflex was confirmed through an electrodiagnostic study, and detrusor underactivity was confirmed through a urodynamic study, leading to a CES diagnosis. Unlike typical cases of osteoporotic SIF, the fracture occurred at an atypical location. We believe that long periods of sitting caused a different weight-bearing pattern of the sacrum from that found in typical cases.

Keyword

Insufficiency fracture; Cauda equina syndrome; Osteoporosis