Predictive value of clinical characteristics in patients with suspected cauda equina syndrome

Overlooking a potential diagnosis of cauda equina syndrome (CES) can result in severe long-term neurologic deficits. There is a growing trend to order urgent magnetic resonance imaging (MRI) scans of the lumbar spine in any patient presenting with signs suspicious for CES. A substantial number of these MRI scans do not show cauda compression. The purpose of this study is to assess whether clinical characteristics can predict MRI-confirmed cauda compression.

We retrospectively studied 58 consecutive cases of suspected CES who presented at our hospital's emergency room.

Eight of 58 patients had cauda compression on MRI. When measured, MRI + CES patients (6) had more than 500 ml urinary retention. Moreover, when these patients had at least two of the following characteristics: bilateral sciatica, subjective urinary retention or rectal incontinence symptoms, MRI was more probable to demonstrate cauda compression with an OR of 48.00, 95% (CI 3.30-697.21), which was also significant (P of 0.04). The presence of other symptoms or signs alone was not significantly different between both groups.

In our series, urinary retention of more than 500 ml alone or in combination with two or more specific clinical characteristics were the most important predictors of MRI confirmed cauda compressions.