Disc Herniation and Radiculopathy

A herniation is a focal displacement of disc material beyond the vertebral body margins. Lumbar disc herniation is the pathologic condition for which spinal surgery is most often performed. Lumbar intervertebral disc herniation typically occurs as a result of age-related changes within the extracellular matrix of the intervertebral disc.

Several occupational factors are believed to be associated with an increased risk of sciatica and disc herniation :

• frequent heavy lifting
• frequent twisting and bending
• sedentary activity
• driving

The clinical syndrome of sciatica is a direct result of the effect of the disc herniation on the adjacent nerve root. This leads to radiculopathy, which is characterized by radiating pain following a dermatomal distribution.

Mechanical Deformation

The extent of the nerve root compromise by mechanical deformation is a result of several effects :

• impaired blood supply
• edema
• onset of compression (rapid or slow progression)
• compromised CSF-related nutritional fluid flow
• level of compression (one or multiple)

Most lumbar disc herniations occur between 30 and 50 years of age. Low back pain may or may not be present.

Symptoms of a symptomatic disc herniation are:

• radicular leg pain
• sensory loss
• motor weakness

Additional but less frequent findings may be:

• paresthesia in the affected dermatome
• radicular pain provoked by pressing, sneezing or pressing
• pain relief in supine position with hips and knees flexed
• previous episodes of acute back pain

Symptoms in children and adolescents can differ significantly:

• predominant back pain
• radicular or pseudoradicular leg pain
• hamstring tightness
• difficulties stooping and picking up things
• restriction in running and jumping
• diminished stride

In very rare cases, patients present massive disc herniation that compresses the cauda equina, causing cauda equina syndrome. Symptoms may be :

• incapacitating back and leg pain
• numbness and weakness of the lower extremities
• inability to urinate (early)
• paradoxic incontinence (later)
• bowel incontinence (late)