Back Pain

Approach to Back Pain

• Xrays: Poor test, but done anyways
  • spinal metastasis (60% sensitivity, 17% specificity)
  • steomyelitis (82% sens, 57% spec)
• CT/MRI
  • Study found herniated disks in 25% of asymptomatic ppl. (most asymptomatic)
  • Does not correlate well with clinical symptoms
  • MRI: better for soft tissue (herniated disks, tumors)
  • CT: better for bone (osteoarthritis)

Cauda Equina Syndrome

• Acute loss of function of the lumbar plexus due to compression, trauma, or other damage.
• Triad:
  • Urine Retention / Fecal incontinence
  • Saddle anesthesia
  • Ataxia
• Any patient with suspected cauda equina needs post-void residual  (positive if volume >200cc).  A negative post-void residual essentially rules out cauda equina.
• NEED MRI IF SUSPECTED
• CT does not have enough sensitivity/specificity for cord compression syndromes (only bony).  
• CT myelogram is an option if MRI not available

Causes

• Mechanical Pain (97%)
  • Lumbosacral Strain (MOST COMMON)
  • Herniated Disk (4%) - leg pain often worse than back pain, radiates below knee
  • Spondylolisthesis (2%)
  • Degenerative
    • Degenerative Disk or Facet (10%) - older, similar findings to lumbosacral strain
    • Spinal Stenosis (3%) - pain better when spine flexed or seated (open post. comp.), worse walking downhill
    • Osteoporotic Fractures (4%) - spine tenderness, hx of trauma
• Nonmechanical Spinal Conditions (1%)
  • Neoplasia
  • Inflammatory
  • Infection

Physical Exam

• .Screening for herniated disk: ask for sciatica (if pain radiates below knee)
  • (95% of herniated disks have sciatica)
•  

Lumbosacral Strain & Disc Herniation

• Continue daily activities as tolerated, use pain as limiting factor.
• No bed rest (only a bit if needed), shown to prolongue recovery.
• Tylenol, NSAID, opioid analgesics.
• Spinal traction, massage, diathermy (electrically induced current producing heat), ultrasound, biofeedback, acupuncture no proven benefit.
• Follow-up in 4-6wks with primary care.
• Return if RED FLAGS.

Treatments/Outcomes

• Education
  • Natural history of back pain is favourable overall
    • 30-60% improve in one week
    • 60-90% recover in six weeks
    • 95% recover in 12 weeks.
  • Relapses common.
• Drugs:
  • Tylenol
  • NSAIDs at antiinflammatory doses.  (use H2 antagonist or misoprostol)
  • Narcotics (short term narcotic is acceptable, if needs long term - re-evaluate cause of pain).
  • Early mobility + Early return to work.  (LBP correlates to low job satisfaction)
• Surgery
  • No benefit, unless Red Flags.

Cervical Radiculopathy

• Nerve root compression at cervical spine
• Nerve roots exit above the level of the corresponding pedicle (unlike Lumbar spine).
• Mechanisms:
  • Herniated disk. (soft disk herniation)
  • Encrouachment by surrounding degenerative or hypertrophic bony elements (hard disk pathology)
  • Associated inflammation, vascular response, and intraneural edema contribute to pain.
• Pain:
  • Patterns:
    • Soft disk herniation: acute presentation, with or without radiating extremity sx.
    • Spondylosis: Chronic bilateral axial neck and radiating arm pain.
      •  
      • Can have many sources, but notably:
        • Degenerative disk
        • Facet joints
  • Classically pain radiates from neck or upper back down the arm, past the elbow.  (absence of radiating extremity pain does not precloude root compression)
• Specific Exam:
  • Symptoms exacerbated by Spurling Sign (extension and rotation of neck)
    • 
    • Holding arm above head (Shoulder abduction sign) decompresses nerve root - helps symptoms.
• Myelopathy vs Radiculopathy
  • Myelopathic symptoms: difficulty manual dexterity, gait disturbance, upper motor neuron signs (Hoffman sign, Babinski, hyperreflexia, clonus)
• Imaging:
  • Xrays:
    • Antero-posterior open-mouth.
    • Anteroposterior lower cervical
    • Neutral lateral.
  • If unclear if radiculopathy or entrapment syndrome in upper limb do electromyography.
  • MRI if persistent symptoms (do CT if has steel cervical hardware)
• Tx:
  • Non-operative:
    • Non-operative is suggested, use multimodal approach
    • 1.  Immobilization (Cervical collar):
      • A short course (one week) may reduce symptoms in inflammatory phase. 
      • Not proven to alter course or intensity of pain.
    • 2.  Traction  (Cervical traction unit)
      • In theory: Distracts neural foramen and decompresses nerve root.
      • 12lb applied on angle of 24 degrees at 15-20minute intervals.
      • Only beneficial when muscular pain subsided, do not use in myelopathy.
      • Recent systematic review: (2012) insufficient evidence for management of chronic symptoms.
    • 3. Pharmacotherapy
      • No proven benefit for cervical radiculopathy. (but positive results in lumbar and low back pain sugest potential role).
      • NSAIDs: show to be effective for low-back pain, often considered first-line.
      • May add narcotics, muscle relaxants, antidepressants, or anticonvulsants.
        • Opioids may be effective in neuropathic pain of up to 8wks duration. (insufficient evidence beyond 2 months).
        • Muscle relaxants (Cyclobenzaprine [Flexeril]) may help acute neck pain by reducing tension.
        • Tricyclic Antidepressants and Venlafaxine (Effexor): may produce moderate relief in chronic neuropathic pain.
        • Tramadol may provide significant relief of neuropathic pain.
        • Oral Steroids: widely used for radicular pain, but no evidence they alter the course.  
    • 4. Physiotherapy
      • Beneficial in restoring ROM and conditioning of neck muscles.
      • Principles:
      • In first 6 weeks: gentle ROM + stretching exercises
        • Supplement w/ massage, heat, ice, electrical stimulation
      • When pain better: isometric strengthening and increased ROM exercises.
      • Spinal Manipulation: no evidence.  May cause harm (worsen).
    • 5. Steroid injections
      • Perineural steroid injections (trans-laminar, transforaminal epidural, selective nerve root blocks).  
      • Do only if confirmed pathology on CT/MRI.
      • One study: significant pain relief at 14 days and 6mo F/U after a series of blocks.
      • Another study: 21 pts awaiting surgery: Improved pain + reduced need for surgery.
      • Another study: no difference.
      • Complications are rare:
        • 1.66% or minor, and <1% for major (spinal/brainstem damage)
      • Another study: epidural Corticosteroids may give short-term improvement of radicular symptoms.

• Indications for Surgery:
  • Intractable pain.
  • Sensory deficit
  • Objective weakness
• Prognosis:
  • 31% had recurrence
  • 26% needed surgery for intractable pain, sensory deficit, objective weakness.
  • Natural history study: 51 pts followed for 2-19 yrs.  At 2 months:
    • 43% no symptoms
    • 29% mild or intermittent symptoms.
    • 27% disabling pain.
    • NONE progressed to myelopathy
  • Overall: 90% asymptomatic.

Reference: AAFP article