Tandem spinal stenosis: a case of stenotic cauda equina syndrome following cervical decompression and fusion for spondylotic cervical myelopathy

Abstract

Tandem spinal stenosis is a clinical phenomenon which may cause a functional loss related to neurologic compression in numerous areas of the spinal cord. In this phenomenon, the second area of symptomatic neurologic insult is not revealed until the primary symptomatic area has been treated. This case describes a 71-year-old male referred to physical therapy 4 weeks following a combined anterior/posterior C3/4 decompression and fusion for treatment of cervical spondylotic myelopathy. Approximately 8 weeks post-operatively (4 weeks after initiation of physical therapy), the patient began to complain of bilateral lower extremity weakness, primarily with climbing stairs. At 12 weeks post-operatively, the patient developed bowel incontinence and saddle paresthesia. Magnetic resonance imaging revealed multiple levels of critical stenosis of the lower thoracic and upper lumbar spine, which resulted in referral for surgical intervention. Following surgical decompression there was complete recovery of lower extremity strength, saddle area sensation and bowel function. This case highlights the need for the clinician to remain vigilant for concomitant pathology despite successful surgical intervention. A thorough knowledge of the presentation of various spinal disorders, as well as a thorough neurologic examination, is required to accurately recognize both candid and subtle red flags requiring immediate referral for surgical intervention.

Keywords: Cauda equina syndrome; Concomitant conditions; Myelopathy; Spinal stenosis.

Figure 1

Pre-operative cervical sagital T2 image demonstrating significant narrowing of spinal canal, with significant area of increased signal intensity in the spinal cord, representing myelomalacia.

Figure 2

Body chart demonstrating patient's areas of sensory change at initial evaluation. Areas marked with "X" represent numbness or tingling.

Figure 3

Body chart demonstrating patients areas of sensory change at 12 weeks post-operatively, corresponding to initial complaints of Cauda Equina syndrome. Areas marked with "X" represent numbness or tingling.

Figure 4

T2 sagital image indicating areas of significant stenosis with increased signal intensity within the distal conus medullaris. Note the change in angulation of the neural structures at the T12-L1 level (uppermost arrow). Arrows indicate involved levels of T12-L1, L1-2, and L4-5.

Figure 5

T2 axial image demonstrating significant central canal stenosis at L1-2, with central disc bulge.

Figure 6

Axial T2 image at the L4-5 level demonstrating central and foraminal stenosis.