CES may be difficult to initially diagnose as patients do not always complain of pain and it may occasionally develop slowly. However, the majority of cases develop suddenly and progress rapidly - sometimes within hours. (1)
About 50-70% of patients have urinary retention on presentation, and up to 50% have an incomplete syndrome. (2)
Characteristically, there is; (3)
- urinary and faecal incontinence
- sensory numbness of the buttocks and the backs of the thighs
- lower motor neurone weakness, the precise features of which depend upon the level at which the cauda equina is compressed. Commonly, the foot becomes flail with loss of dorsiflexion of the foot (L4) and toes (L4,5), and of eversion and plantarflexion (S1). The ankle jerks are usually absent on both sides.
'Red flags' for CES include: (4)
- Acute onset of urinary retention or overflow incontinence (retention and overflow incontinence are signs of CES that may be irreversible.)
- Loss of anal sphincter tone or faecal incontinence
- Saddle anaesthesia
- Bilateral or progressive weakness in the lower limbs.
Note;
- bladder dysfunction is always present at some stage in the progression of CES (5)
References
- Lavy C, James A, Wilson-MacDonald J, et al; Cauda equina syndrome. BMJ. 2009 Mar 31;338
- Gardner A, Gardner E, Morley T; Cauda equina syndrome: a review of the current clinical and medico-legal position. Eur Spine J. 2011 May;20(5):690-7
- Barraclough K. Cauda equina syndrome. BMJ. 2021 Jan 12;372:n32.
- Expert Panel on Neurological Imaging., Hutchins TA, Peckham M, et al. ACR appropriateness criteria® low back pain: 2021 update. J Am Coll Radiol. 2021 Nov;18(11s):S361-79.
- Kuris EO, McDonald CL, Palumbo MA, et al. Evaluation and management of cauda equina syndrome. Am J Med. 2021 Dec;134(12):1483-9.