23A. Lumboischialgia and chronic back pain

Lumboischialgia and low back pain are two manifestations of spinal cord disease. Lumboischialgia is characterised by the presence of neurological symptoms other than radiating pain, like weakness, sensory loss, or reflex loss. Usually L5 and/or S1 are affected.

In non-specific low back pain there are no neurological symptoms. This condition is very common, and often occurs in otherwise healthy individuals.

The other manifestations of spinal cord disease are cervicobrachialgia and lumboischialgia (topic 13A).

Etiology

• Trauma to the back
• Spondylosis (age-related arthritis of the spine)
• Spinal disc herniation
• Spinal stenosis
• Spinal tumour

In case of non-specific low back pain, there is often no underlying pathology to be detected. Muscular or ligamental strain may be involved.

Clinical features

The neurological symptoms of lumboischialgia depend on the nerve root which is affected. The symptoms may be weakness and atrophy, sensory loss, reflex loss, and radicular pain. Low back pain may be present.

• If L5
  • Sensory symptoms on lateral surface of thigh, anterior surface of calf
  • Motor symptoms of extensor hallucis longus -> foot drop
  • Loss of tibialis posterior reflex
• If S1
  • Sensory symptoms on lateral surface of calf
  • Motor symptoms of peroneus muscle, triceps surae
  • Loss of Achilles reflex

Lasegue sign is positive in lumboischialgia and negative in low back pain.

Diagnosis and evaluation

Imaging is only necessary in cases of severe symptoms.

Treatment

Treatment is conservative, unless the symptoms are severe, in which case surgery may be an option. Most cases of low back pain are self-limiting.