Back Pain

Background

•30 million adults in UK /yr experience back pain

•1/3 experience pain> 12 months and 1/5 of above will be off work >3/12

•Costs NHS £1.3 million/day•Large scale all around cost- NHS

approved campaign- BackCare Awareness Week 08-12 October 2014

Red Flags

Focal neurological symptoms/signs- incl. Cauda Equina

TraumaThoracic region painUnintentional weight lossLong term steroid useNight sweats- symptoms of general

malaiseHistory of Bone disease

Cauda Equina Syndrome(CES)• Back pain• ‘Saddle anaesthesia’- S3-

S5 dermatome• Bowel and bladder

dysfunction• Paraplegia• Multiple causes• Urgent MRI- low

threshold if high clinical suspicion

• Tx- Urgent Decompression/Discectomy

• ‘Time is function’

Disc Prolapse• Usually following

minor-moderate injury

• More likely in young-middle aged

• Unlikely to be >70s due to loss of volume of nucleus pulposus

• Higher propensity- L4/L5 and L5/S1

Spinal Stenosis• Cervical and

Lumbar stenosis- common sites

• Central – usually• Discomfort whilst

standing-94%• Symptoms

related to level of stenosis

• Lumbar flexion helps

As a continuum…

Minor/Moderate injury Acute onset

pain

Resolves with rest /analgesia

Slight protrusion of nucleus pulposus

Re-injuryFurther prolapse

Neurological deficit either transient/established

Re-injuryIncreased risk for CES

Spinal stenosis

Minor Injury

Other causes• Leriche syndrome- buttock

pain- aorto-iliac occlusive disease

• Part of disease process- Multiple Myeloma, Prostate Ca

• Potts’ abscess-extrapulmonary TB

Pain

•In >70% of patients presenting with back pain- Chronic LBP

•Usually spasmodic exacerbations on a background of constant pain

•Can usually treat the exacerbations, background pain- poorly controlled

•Area where subjective scoring of pain has significant variations with time

Case Scenario

•38 yr old lady presented with lower back pain of 2/52

•Minor back injury 2/52•Worsening pain over the previous 3-4/7•Recent weight gain•Shooting pain down from back and front to

left knee•Numbness over left lateral thigh•No associated bladder or bowel dysfunction

noted

Examination findings• In obvious discomfort• No evidence of unilateral muscle wasting• Some generalised discomfort over L3/L4 vertebrae but

no pinpoint tenderness noted• Flex hip to 110 degrees (L side) , internal and external

rotation preserved• Lumbar flexion largely preserved• SLR normal both sides, lasegue test negative• Femoral stretch test equivocal on left side• Reduced sensation over lateral aspect of left thigh• Slightly diminished reflexes at left knee> R knee• Power reduced to 4/5 LLL possibly due to pain

Lower limb dermatome

Lasegue’s test and SLR

• SLR- note angle at which pain is reproduced

• Lasegue test- dorsiflexion with SLR- reproducing pain

• Both indicative of L5/S1 primary nerve root involvement

Discussion of findings

•No evidence of spinal cord compression•No evidence of cauda equina•No evidence of hip involvement•SLR and Lasegue's test being negative-

rules out true sciatica•True sciatica- burning pain radiating to

heel and lasegue's test would be positive- compress L5/S1 disc space

Likely explanation

•Femoral nerve roots involvement- primarily L3/L4- possibly entrapment ? Disc prolapse

•Could be a component of meralgia paraesthetica

•Classical symptoms of burning pain and localised anaesthesia

•Lateral cutaneous femoral nerve involvement

•Usually related to diabetes, weight gain, tight clothing related

Management•Simple analgesia•Weak opioids•Large role of anti-neuropathic type of

medications- e.g. gabapentin, amitriptylline•Large proportion of patients get symptomatic

relief•Small proportion develop longstanding pain•The above management was instituted•Explained if pain does not settle•Will need imaging- MRI, EMG(not routinely)