THE COMPRESSED NERVE Timothy Jones PhD FRCS(SN) Consultant Neurosurgeon
MY BACKGROUND Consultant Neurosurgeon at St George s Hospital Trained in the region Subspecialty interest in neuro-oncology & trigeminal neuralgia Neuro-oncology lead & academic interest Degenerative spine clinic Mon & Tues www.southlondonneurosurgery.com timothy.jones@stgeorges.nhs.uk Secretary: 0208 725 4182
PLAN FOR THIS MORNING Summary of spinal bread and butter My approach to a common problem Evidence based treatments Q&A
HOW MUCH OF A PAIN IS THE LUMBAR SPINE IN GENERAL PRACTICE? Spinal disorders are common Multi-factorial aetiology No standardised treatment Absence of robust evidence Some patients do very well, some very bad Functional overlay Medico-legal burden Increasing access to imaging and increasingly defensive reports
LOW BACK PAIN & LUMBAR DISC DISEASE Second commonest reason for seeking a medical opinion 15% of all sick leave Annual incidence 5% Common, no diagnosis in 85% 89-90% will improve within 1 month
CHANCES OF THE PATIENT GOING BACK TO WORK Better if self-employed 6 months or less out of work 50% chance 1 year out of work 20% chance 2 years out of work <5% chance
DEGENERATIVE DISC DISEASE Progressive deterioration of structures of the spine 1. Disc abnormality Decreased proteoglycans Loss of hydration Tears of the annulus Herniation of disc Loss of disc height 2. Facet joint hypertrophy and joint laxity 3. Osteophyte formation 4. Hypertrophy of lig. Flavum +/- spondylolisthesis
RISK FACTORS Rarely identified Probably over-estimate effect of physical loading Obestity & sedentary Axial loading Runs in families Gets worse with age continuum of degeneration
SCENARIO 1 45F, previously fit and well 4 days ago was lifting a heavy box out of her car Next day lower back pain and rapid onset pain into both calves Today reports a around groin numbness less control over urinary stream Weak ankle dorsiflexion
SCENARIO 1 Cauda equina syndrome until proven otherwise Recommend Expedited admission to local A&E MRI scan Transfer for surgery Avoid Wait and see Trial of analgesia Eating and drinking! Waiting to call the on call team at the local hospital
CES SYMPTOMS Urinary retention (90% sensitivity) Post void bladder residual No retention, chance of CES 1 in 1000 Reduced sphincter tone Saddle anaesthesia Motor weakness Sciatica (uni or bilateral) Absent ankle jerks Sexual dysfunction (late)
CES CAUSES Disc prolapse (L4/5) Tumour Infection (epidural abscess) Neuropathy
CES HOT TOPICS Time to surgery Laminectomy vs. discectomy Medico-legal issues Take home point: Time is function Perineal anaesthesia is a bad sign Good documentation essential
SCENARIO 2 (MORE COMMON) 58M, Works as a taxi driver, PMHx of Type II diabetes, obese and generally inactive 8 months of twinge of pain in left buttock, occasionally travels down back of thigh to knee Worsening lower back pain when sitting cant do my job No weakness or any bladder symptoms Pain is affecting his work Has been a repeat attender Rx paracetamol, NSAIDS cause tummy upset, did not tolerate amitriptyline doesn't like to take tablets Dr.
SCENARIO 2 WHAT COULD YOU DO? Options: Physiotherapy Try NSAID with PPI Gabapentin/Pregabalin Lifestyle advice: exercise, weight loss Ultimately get an MRI
SCENARIO 2 MRI REPORT Degenerate disease Mild lateral recess stenosis... Facet joint hypertrophy... Bulge in L4/5 disc which may be touching the L5 nerve root... Modic changes... Final line: recommend spinal/neurosurgical opinion...
SCENARIO 2 - MRI Combination of disc, osteophyte and thickened ligament causing LATERAL RECESS STENOSIS Causes back pain and neurogenic leg symptom (L4/5, L5 root +/- S1 root)
SCENARIO 2 - WHAT ARE THE OPTIONS? Good Options Lifestyle advice Pilates/physio Trial of neuropathic pain agent Nerve root injection Facet joint injection (maybe) Bad Options Opiates/Muscle relaxants/steroids Spinal brace TENS Prolonged bed rest Traction Provocative discography Overly aggressive surgery
IS SURGERY AN OPTION? In general, yes Surgery: GA, 1 to 2 day admission 3-4 cm midline scar Window in the spinal canal Nerve root decompression Evidence: None!
SCENARIO 3 75F, history of OA, ex-smoker, hypertensive Last 3 years, progressively deteriorating mobility Heaviness in legs, worse on exertion Having to stop when walking long distances Losing confidence Bladder/bowel OK Normal neurological exam, stooped posture
SCENARIO 3 DIFFERENTIAL DIAGNOSES Lumbar canal stenosis/spondylolisthesis Vascular claudication Hip disease/trochanteric bursitis Spinal tumour Spinal AV malformation Diabetic neuritis Inguinal hernia
SCENARIO 3 What are the options? NSAIDS Mobility assessment/falls risk Cardio/vascular risk assessment MRI scan Hip x-ray
SCENARIO 3 MRI
FEATURES OF LUMBAR CANAL STENOSIS Uni or bilateral buttock/thigh/leg pain, may get burning dysaesthesia Precipitated by standing or walking Relieved by sitting/bending forward Slow relief of symptoms at rest (cf. vascular claudication) also claudicant distance variable Normal neurological exam in 20% Exclude: vascular claudication, hip pathology, diabetic neuritis No need for X-rays, straight to MRI L4/5 > L3/4
LUMBAR CANAL STENOSIS (MANAGEMENT) NSAIDS Physiotherapy Avoid braces/support orthoses Surgery (if symptoms > 3 months) Laminectomy Inter-spinous spacer (X-stop) Anterior lumbar interbody fusion (ALIF) Decompression and pedicle screw fusion Caudal epidural injection
SCENARIO 3 IS THERE ANY EVIDENCE? None for Interspinous devices, ALIF
NEJM PAPER SWEDISH SPINAL STENOSIS STUDY 247 patients with spinal stenosis Randomised into laminectomy or laminectomy plus fusion Outcomes: patient reported, walk test, health economic evaluation, ODI No difference in outcomes at 2 and 5 years Simple decompression: shorter length of stay (median 4 days) less blood loss shorter operation time cheaper
LUMBAR LAMINECTOMY 2 day admission Prone position X-ray confirmation of level Midline incision Muscle strip De-roofing of canal with drill and upcut rongeurs Central and lateral canal decompression Epidural steroids
SURGICAL RISKS Infection 1% (superficial vs. deep) Unintended durotomy 3% Motor deficit Post op urinary retention Post op visual loss (v. rare) CES (v.rare) Spinal instability (est. 1%) In general, well tolerated procedure
SCENARIO 4 40M, generally fit & active, works full time, no PMHx Back pain for a week after cycling holiday Sudden left sided sciatica started 1week later, lasting for 3 months Numb lateral foot on left Absent ankle jerk Has tried physio Taking regular NSAID Has had a nerve root injection which worked for 2 days
SCENARIO Cant sit down in clinic room Hurts when he coughs Limp with pain Cant stand on tip toes Limited straight leg raise Clinical Diagnosis: S1 nerve root compression
SCENARIO 4 MRI SCAN
OPTIONS Reassurance Neuropathic pain agent Nerve injection Surgery Microdiscectomy Laminectomy and discectomy Bad options Intradiscal procedures: laser disc therapy, percutaneous endoscopic discectomy, intradiscal endothermal therapy Crutches Back supports
SPORT SPINE PATIENT OUTCOME RESEARCH TRIAL Surgery vs non operative for lumbar disc herniation 500 patients with proven lumbar disc and symptoms for > 6 weeks randomised into surgery or best conservative therapy After 2 years no difference in function or symptoms on intention to treat analysis But!!! Only 50% of those assigned to surgery had an operation and 30% assigned to conservative therapy had a discectomy! Highlights the issues with surgical trials (crossover, blinding, ITT analysis)
MICRODISCECTOMY Well tolerated procedure 1-2 day admission Small scar Risks as before, includes discitis And recurrent disc prolapse
SUMMARY Scenario 1 CES Scenario 2 Lateral recess stenosis Scenario 3 Lumbar canal stenosis Scenario 4 Prolapsed disc
WHAT DOES A NEUROSURGEON REALLY THINK? Prolapsed disc great, will either get better by itself or surgery likely to cure Lumbar canal stenosis if symptoms are bad, surgery will be a great relief Lateral recess stenosis if you identify the correct level then result will be good Back pain in isolation surgery has a very low yield in making patient better A lot to be said for trying a decent neuropathic agent Do encourage exercise Be sceptical of unproven revolutionary spinal surgery!