The nerve in the spine that controls the bladder is called the Sacral Spinal Cord.
When that Sacral Spinal Cord nerve is compressed it can interrupt messages from your brain to your bladder and can cause urinary incontinence.
If you've had a spinal cord injury it is possible to develop Urinary Incontinence from the Spinal Cord Injury if the nerve that controls the bladder is compressed or injured in any other way.
The only cure for incontinence from a spinal cord injury is surgery to be performed on your spinal cord and nerves controlling your bladder.