Regarding central disc herniations, the bulge can cause a number of symptoms and it is the type and intensity of symptoms that need to be addressed.
If the symptoms are mild as many central disc herniations are, nothing needs to be done or a conservative rehabilitation program needs to be started. If the symptoms are more problematic, an epidural injection can be considered.
If the disc herniation is larger and causes central stenosis, the symptoms of neurogenic claudication can occur (see website). In this case a microdiscectomy will address the symptoms.
If the symptoms are lower back pain only (without the presence of the degenerative spondylolisthesis), a microdisectomy can be considered with a success rate of about 50-60 %. With the degenerative spondylolisthesis, a fusion needs to be considered for lower back pain.