Intervertebral Disc Prolapse
Definition: A Herniation of the annulus fibrosus of an intervertebral disc most frequently seen in the lumbar region
Causes Protrusion of the nucleus pulposus though a weakness in the fibrocartilagenous annulus. Causes include acute trauma ie. from lifting a heavy object or by long term degenerative changes to the structures of the spine (spondylosis). Symptoms include low back pain, muscle spasm, leg pain (sciatica), numbness and weakness in the affected area.
Examination Symptoms depends on the direction and size of the prolapsed material. Usually in a posterolateral direction it will affect the exiting intervertebral nerve root causing the radiation of neurological symptoms in the distribution of the affected root. With a central prolapse, if significant it may result in cauda equina syndrome. Tests include straight leg raise test for lower upper roots, femoral nerve stretch test for upper lumbar roots, tendon reflexes, plantar, cremasteric and anal reflex, sensory modalities tests.