Abstract
In this study we aim to establish which symptoms and signs are able to reliably predict the presence or absence of cauda equina syndrome.
Prospective collection of data was carried out over 10 months on all patients referred with suspected cauda equina syndrome(CES) to a single spinal unit. 28 patients were referred.
MRI was normal in 4 (14%) patients. 4 (14%) had disc prolapse causing CES and 3 (11%) had spinal metastatic disease. All patients with CES presented with low back pain, unilateral sciatica, urinary dysfunction (painless retention 2, incontinence 2), altered perianal sensation and abnormal anal tone. 1 described constipation. Of patients without CES or malignancy 21 (100%) complained of low back pain, 19 (90%) sciatica (15 unilateral, 4 bilateral), 12 urinary dysfunction (incontinence 5, reduced sensation 3, painless retention 2, urgency 1, terminal dribbling 1) and 5 described altered bowel habit. 7 (33%) exhibited altered perianal sensation and 1 (5%) abnormal anal tone.
The patients with spinal metastases all described back pain but no sciatica. 2 had urinary retention and constipation with 1 having abnormal perianal sensation and anal tone.
This study suggests abnormal anal tone (sensitivity 1.0, specificity 0.95) and altered perianal sensation (sensitivity 1.0, specificity 0.67) are the most reliable predictors of CES. Thorough clinical examination is essential. Back pain with bladder and/or bowel dysfunction without sciatica should raise the suspicion of malignancy.
