Musculoskeletal System >
Sciatica (Lumbar Radiculopathy)
“Symptoms of pain, tingling, and numbness which arise from nerve root compression or irritation in the lumbosacral spine”
Risk Factors
- Increased risk of developing sciatica:
- Strenuous physical activity, for example, heavy lifting or jogging.
- Whole-body vibration, for example, driving.
- Modifiable factors associated with the first onset of sciatica:
- Smoking
- Obesity
- Occupational factors
- General health
Aetiology
- A herniated intervertebral disc (90% of cases), Spondylolisthesis, Spinal stenosis.
- Cancer and infection (rare).
Pathophysiology
- Sciatic nerve L4-S3 can be damaged by pelvic tumours or fractures to pelvis or femur.
- Lesions affect the hamstrings and all muscles below the knee (> foot drop), with loss of sensation below the knee laterally
Clinical Presentation
- Unilateral leg pain radiating below the knee to the foot or toes.
- Low back pain, numbness, tingling (paraesthesia), and muscle weakness in the distribution of a nerve root (dermatome).
- Red flags:
- Cauda equina syndrome
- Spinal fracture
- Cancer
- Infection (such as discitis, vertebral osteomyelitis, or spinal epidural abscess)
Investigations
- Positive straight leg raising test, Extensor plantar response
- XRay of the lumbar spine
- CT and MRI imaging only to be requested if serious underlying pathology is suspected
Management
- Admission or urgent referral to a neurosurgeon or orthopaedic surgeon if:
- Red flag symptoms are present
- There is a progressive, persistent, or severe neurological deficit
- Adequate analgesia (an NSAID first-line, or codeine with or without paracetamol if an NSAID is contraindicated or not tolerated).
- If analgesia is not effective, drugs to treat neuropathic pain can be prescribed.
- Assess the risk of back pain disability using a risk stratification tool.
- Offer higher risk patients referral for group exercise, and/or cognitive behavioural therapy, and/or physiotherapy.
- Consider referral to low back pain specialist referral for an epidural corticosteroid/ local anaesthetic injection.
- Assessment for radiofrequency denervation, or spinal decompression if non-surgical treatment has not improved pain or function.
- Provide information about its expected time course, self-help measures, advice about staying active, resuming normal activities, and returning to work as soon as possible.
Complications
- Permanent nerve damage
- Psychosocial problems eg Anxiety, depression, and impact on family
- Loss of employment from time off work, reduced productivity