1. Cauda Equina By Hugh Pelc Bsc, MBBS, MRCS, MRCGP

2. This is a serious business Cauda equina syndrome occurs in approximately 2% of cases of herniated lumbar discs The cauda equina are LOWER motor neurones and sensory nerve roots. They do not show good healing compared to UPPER motor neurones Good evidence suggests surgery should be performed within 24h of the onset of symptoms Complications of untreated/delayed treatment include incontinence and sexual dysfunction. More than 1000 operations/y performed in England alone i.e. NOT RARE Average litigation payout 336,000 GBP

3. Aims Understand anatomy pertinent to Cauda Equina syndrome Understand what Cauda Equina Syndrome is Know the important symptoms of Cauda Equina Know the important aspects of examination for Cauda Equina Know when referral is indicated Educators love aims and objective slides

4. What is the cauda equina and why is it so special anyway?

5. What is Cauda Equina Syndrome?

6. Disc Bulge

7. Cauda Equina

8. Why is it so bad? The disc squishes all of the nerve roots This therefore includes those innervating the bladder, bowels and genitals Consequently incontinence, global weakness/paralysis and sexual dysfunction are risks Don't forget these are lower motor neurones and heal badly This is a “chunk and check” slide

9. Classic History Develops rapidly over hours-days Sometimes on background of established sciatica Here are the “classic signs”: Paraesthesiae Motor abnormality 1)Bilateral sciatica 2)Altered perineal (peri-anal) sensation 3)Absence of urge to micturate 4)Urinary retention/incontinence (overflow) 5)Faecal incontinence/constipation 6)Altered genital sensation 7)Sexual dysfunction (i.e. erectile dysfunction)

10. Hang on a minute... How do we know that altered perianal sensation or any other “classic sign” is not from normal sciatica? i.e. from a paracentral disc bulge

11. Because there aren't any discs below the L5/S1 disc So the S2 root cannot be compressed by a paracentral disc bulge Nor can the S3,4 or 5 roots! Innervation of perianal sensation/bladder function/bowel function/genital sensation is all from lower sacral nerve roots

12. HISTORY: What to ask Step 1: Confirm that this really is sciatica – i.e. dermatomal shooting pain extending below the knee It is unlikely to be sciatica if there is no pain below the knee 95% disc prolapse occurs at L4/5 or L5/S1 If there is no pain below the knee establish the dermatome carefully Step 2: Ask for the “classic signs”.

13. HISTORY: What do we really need to ask? “Do you still notice the urge to pee?” “Have you wet yourself at all” “Do your privates still feel normal when you wipe?” (female) “Does your penis feel tingly?” and “Have you started having trouble getting erections?” (male) “Do you ever get the pain in the other leg?” “How are your bowels?” “Have you noticed any pins and needles around your back passage?” BEWARE: codeine, previous incontinence/ED, pain that isn't sciatica “You might have trapped a nerve” “The nerve causes pain in your leg but it might also control your bladder, bowel or private parts”

14. HISTORY: Summary Establish a history of dysfunction in a nerve supplied by S2 or lower. Bladder Bowel Genitals Perineum “This is a chunk and check slide”

15. EXAMINATION: What should we do? STEP 1: Establish sciatica Check for dermatomal paraesthesiae Check for myotomal weakness STEP 2: Special tests to help establish sciatica SLR until pain ellicited Does ankle dorsiflexion worsen pain? Does knee flexion improve pain? STEP 3: Consider testing hip rotation/knee movements.

16. If they admitted to any “classic signs” Glove up people, you're going in.

17. EXAMINATION: Summary Establish Sciatica PR if they admitted to “classic signs” in the history “This is a chunk and check slide”

18. Indications for Referral/MRI Presence of any “classic signs” Just 1 will do.

20. Lower Limb Neuro Examination L2 – Hip flexion L3 – Knee extension L4 – Ankle Dorsiflexion L5 – Hallux dorsiflexion S1 – Ankle Plantarflexion All posterior muscles are S1 (e.g. knee flexion)