Caused by compression of the nerve roots caudal to the level of spinal cord termination
Aetiology
- Most common cause is compression arising from large central lumbar disc herniation at the L4/L5 and L5/S1 level
Clinical presentation
Symptoms
- Classically bilateral leg pain, can be unilateral or with no leg symptoms
- Loss of motor or sensory function of bowel/bladder
- Loss of control/awareness (NOT constipation or increased urinary frequency)
- Perineal/saddle anaethesia
- Widespread or progressive motor weakness in the legs or gait distribution
Signs
- PR exam - loss of anal sphincter tone
Investigations
- Urgent MRI to determine level of prolapse
Management
Complications
- Prolonged compression can cause permanent nerve damage requiring colostomy and urinary diversion
- Even with prompt surgical intervention, significant number of patients have residual nerve injury with permanent bladder and bowel dysfunction