Magnetic resonance imaging of cauda equina syndrome in ankylosing spondylitis: a case report

Cauda equina syndrome in ankylosing spondylitis: successful treatment with lumboperitoneal shunting

STUDY DESIGN

Retrospective study.

OBJECTIVE

To assess outcomes after lumboperitoneal shunting for CES with dural sac dilation and multiple arachnoid diverticula in patients with long-standing AS.

SUMMARY OF BACKGROUND DATA

Cauda equina syndrome (CES) is a rare complication of long-standing ankylosing spondylitis (AS). Neurologic symptoms occur insidiously and have a poor prognosis without effective treatment.

METHODS

We retrospectively studied cases seen between 1997 and 2009 at our university-hospital rheumatology department.

RESULTS

We identified 9 patients with AS and dural sac dilation (mean age: 64, range: 38-75), of whom 8 experienced CES 29.1 years on average (range: 10-51) after AS onset. Presenting symptoms were urinary abnormalities (n = 4), sensory abnormalities (n = 6), or radicular or low back pain (n = 4). The symptoms worsened progressively, with mild (n = 3) to severe (n = 1) motor deficiency, sphincter dysfunction (urinary [n = 6] and/or anal [n = 4] sphincter), and impotence (n = 3). Magnetic resonance imaging showed dural sac dilation (n = 9), multiple lumbar arachnoid diverticula (n = 6), erosions of the laminae and spinous processes (n = 6), and nerve-root tethering (n = 6) with adhesion to the dura mater and vertebrae (n = 7). Cerebrospinal fluid (CSF) flow study by magnetic resonance imaging was performed in 2 patients and showed communication of the diverticula with the CSF. Lumboperitoneal shunting, performed in 5 patients, was followed by improvements in sensation (n = 4), urinary symptoms (n = 2), anal continence (n = 3), and pain. Full recovery of muscle strength was noted in 3 patients. Improvements persisted after a mean of 49 months (range: 18-96).

CONCLUSION

Lumboperitoneal shunting induced substantial improvements in all 5 patients treated with this procedure. This result suggests that AS-related CES may be due to chronic arachnoiditis and dural fibrosis leading to diminished CSF resorption with dural sac dilation and diverticula formation.

Lumbar Dural Ectasia Secondary to Spinal Fusion: A Report of Two Cases

Two cases of lumbar dural ectasia secondary to spinal fusion are presented. Background history of dural ectasia is discussed; computed tomography (CT) and MR imaging characteristics of dural ectasia are shown and possible causes are discussed.

Cauda equina syndrome in ankylosing spondylitis (the CES-AS syndrome): meta-analysis of outcomes after medical and surgical treatments

The cauda equina syndrome in ankylosing spondylitis (the CES-AS syndrome) is marked by slow, insidious progression and a high incidence of dural ectasia in the lumbosacral spine. A high index of suspicion for this problem must be maintained when evaluating the patient with ankylosing spondylitis with a history of incontinence and neurologic deficit on examination. There has been disagreement in the literature as to whether surgical treatment is warranted for this condition. A meta-analysis was thus performed comparing outcomes with treatment regimens. Our results suggest that leaving these patients untreated or treating with steroids alone is inappropriate. Nonsteroidal antiinflammatory drugs may improve back pain but do not improve neurologic deficit. Surgical treatment of the dural ectasia, either by lumboperitoneal shunting or laminectomy, may improve neurologic dysfunction or halt the progression of neurologic deficit.